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Sample records for interspecific crossing barriers

  1. Application of three pollination techniques and of hormone treatments for overcoming interspecific crossing barriers in Tulipa

    NARCIS (Netherlands)

    Creij, van M.G.M.; Kerckhoffs, D.M.F.J.; Tuyl, van J.M.

    1997-01-01

    In tulip, interspecific crossing is restricted by both pre-fertilization and post-fertilization barriers. In order to introduce traits from wild species into the cultivar assortment these barriers must be bypassed. By application of embryo rescue techniques, unique hybrids have been obtained of

  2. Evaluation of reproductive barriers contributes to the development of novel interspecific hybrids in the Kalanchoë genus

    DEFF Research Database (Denmark)

    Kuligowska, Katarzyna; Lütken, Henrik Vlk; Christensen, Brian

    2015-01-01

    BackgroundInterspecific hybridization is a useful tool in ornamental breeding to increase genetic variability and introduce new valuable traits into existing cultivars. The successful formation of interspecific hybrids is frequently limited by the presence of pre- and post-fertilization barriers....... In the present study, we investigated the nature of hybridization barriers occurring in crosses between Kalancho? species and evaluated possibilities of obtaining interspecific hybrids.ResultsThe qualitative and quantitative analyses of pollen tube growth in situ were performed following intra- and interspecific...... pollinations. They revealed occurrence of pre-fertilization barriers associated with inhibition of pollen germination on the stigma and abnormal growth of pollen tubes. Unilateral incongruity related to differences in pistil length was also observed. The pollen quality was identified as a strong factor...

  3. Climate as possible reproductive barrier in Pinus radiata (D. Don interspecific hybridisation

    Directory of Open Access Journals (Sweden)

    Hannél Ham

    2017-12-01

    Full Text Available Historically, interspecific hybridisation with Pinus radiata D. Don had limited success. The effect of environmental conditions and position of pollination bags in the tree were investigated as possible hybridisation barriers. The study was conducted in a P. radiata seed orchard in the Southern Cape (South Africa. Field data were compared to the climatic conditions at natural and commercial provenances of seven Mesoamerican Pinus species identified as possible hybrid partners. In vitro pollen studies were used to confirm whether interspecific crosses with P. radiata might be feasible within predefined climatic parameters. The temperature ranges for both top and northern side of P. radiata pine trees in the seed orchard was similar to the natural distribution of P. radiata, P. elliottii Engelm. and P. taeda L. in the USA. Results suggested that pollen of P. elliottii and P. taeda might be more suited to result in the successful pollination of P. radiata than the other Mesoamerican pine species tested in this study.  Furthermore, the combination of minimum temperature and precipitation also showed a closer correlation to successful hybridisation with P. radiata for both P. elliotii and P. taeda. However, pollen tube elongation studies did not support these results, suggesting that mean temperature might not be the only determining factor of hybridisation success. Three circadian temperature models that mimic natural conditions were developed for Karatara and Sabie (Tweefontein, Witklip and Spitskop.  These models will be tested in future in vitro studies to further evaluate temperature fluctuations between day and night regimes as a possible reproductive barrier limiting hybridisation success between P. radiata and other Mesoamerican pine species.

  4. Introgression in interspecific hybrids of lily

    NARCIS (Netherlands)

    Tuyl, van J.M.; Maas, I.W.G.M.; Lim, K.B.

    2002-01-01

    In order to introduce new desirable characters into the cultivar assortment of lily a range of interspecific crossing barriers has to be overcome. By using various pollination and embryo rescue techniques pre- and postfertilization barriers were overcome and a range of wide interspecific lily

  5. Advances in interspecific pregnancy

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Interspecific pregnancy in which the conceptus and female carrying the pregnancy are of different species is a key step to interspecific cloning. Cloning endangered animals by interspecific pregnancy is such a highlight catching people's eyes nowadays. In this article, the history of interspecific pregnancy, the methods for establishment of interspecific pregnancy, the corresponding theories, barriers and applied prospects are reviewed.``

  6. Interspecific hybridization of flower bulbs: a review

    NARCIS (Netherlands)

    Tuyl, van J.M.

    1997-01-01

    In order to introduce new characters such as resistances, flower shape and colour, from wild species into the cultivar assortment of lily it is necessary to overcome interspecific crossing barriers.. Several techniques have been used for wide interspecific lily crosses with species and cultivars

  7. Interspecific lily hybrids: a promise for the future

    NARCIS (Netherlands)

    Tuyl, van J.M.; Chi, H.S.; Kronenburg-van de Ven, van B.C.E.; Meijer, B.

    1997-01-01

    In order to introduce new characters such as resistances, flower shape and colour, from wild species into the cultivar assortment of lily it is necessary to overcome interspecific crossing barriers.. Several techniques have been used for wide interspecific lily crosses with species and cultivars

  8. Interspecific Hybridisation in Campanula

    DEFF Research Database (Denmark)

    Röper, Anna Catharina

    In the present thesis, economically important Campanula species were selected for interspecific hybridisation to increase the genetic viability in plant breeding material. To reach this goal, ovule culture was established as an embryo rescue technique to overcome post-fertilisation barriers...... had an influence on the number of ovules and germination success in some cross combinations. In the second research part interspecific hybrids obtained from ovule culture were genotypically and phenotypically characterised by AFLP analysis, flow cytometry and biometrical parameters. Hybridity...

  9. Interspecific Hybridization within Ornamental Plants

    DEFF Research Database (Denmark)

    Kuligowska, Katarzyna

    commercially important genera of ornamental plants: Kalanchoë and Hibiscus. The nature of hybridization barriers hampering hybrid production was investigated during pre- and post-fertilization stages. For each genus the interspecific crosses of Kalanchoë species and Hibiscus species, abnormal germination...... and growth of pollen tubes, as well as lower frequencies of pollen tubes were observed in specific cross-combinations. Post-fertilization barriers related to endosperm development and hybrid incompatibility were also observed in Kalanchoë and Hibiscus genus, respectively. Qualitative and quantitative...

  10. Erosion of interspecific reproductive barriers resulting from hatchery supplementation of rainbow trout sympatric with cutthroat trout.

    Science.gov (United States)

    Docker, Margaret F; Dale, Angie; Heath, Daniel D

    2003-12-01

    The frequency of hybridization between cutthroat (Onchorhynchus clarki clarki) and rainbow (O. mykiss irideus) trout from coastal habitats in British Columbia, Canada, was examined in seven populations where the two species are sympatric with no history of rainbow trout stocking and compared with areas where native rainbow trout populations have been supplemented with hatchery fish (three populations). Four nuclear markers were used to identify each species and interspecific hybrids and one mitochondrial marker showed the direction of gene exchange between species. The frequency of hybrids was significantly higher (Fisher exact test, P < 0.001) in river systems where hatchery rainbow trout have been introduced (50.6% hybrids) than in populations where the two species naturally co-occur without supplementation (9.9% hybrids).

  11. Evaluation of wheat genotypes originated from interspecific crossing and gamma radiation

    International Nuclear Information System (INIS)

    Camargo, C.E.O.; Ferreira Filho, A.W.P.; Freitas, J.G.; Tulmann Neto, A.; Pettinelli Junior, A.; Castro, J.L.

    1995-01-01

    Twenty three inbred HEXAPLOID wheat lines were evaluated. They were originated by selections made in populations submitted to gamma radiation (27.5 krad), in the F 4 generation, from the interspecific hybrid between BH-1146 (triticum aestivum L.) and Anhinga S x Winged S (Triticum durum L.) and the cultivars BH-1146 and Yavaros S (T. durum L.) Nine trials were carried out with irrigation and in upland conditions. Several agronomic characteristics were assessed. Under laboratory conditions the genotypes were evaluated with respect to Al toxicity using nutrient solutions. Semi dwarf line 11 and 19, with moderate lodging resistance, medium cycle from emergence to flowering, tolerance to aluminum toxicity, were the most productive. Seven lines showed resistance to the causal agent of mildew, but all genotypes were susceptible to the causal agents of leaf spots. Some of the genotypes could be used in cross breeding as genetic sources for short plant, long head, large number of spikelets per head, large number of grains per head and per spikelet and heavy grains. BH-1146 and seven from the 23 lines were considered the most tolerant to aluminium toxicity, presenting good regrowth after treatment in nutrient solutions with 10 mg/liter of Al +3 . (author). 15 refs., 7 tabs

  12. Genetical and ultrastructural aspects of self and cross incompatibility in interspecific hybrids between self-compatible Lycopersicum esculentum and self-incompatible L. peruvianum.

    Science.gov (United States)

    De Nettancourt, D; Devreux, M; Laneri, U; Cresti, M; Pacini, E; Sarfatti, G

    1974-01-01

    Cytological and genetical analyses were made of the breeding system of embryo-cultured interspecific tomato hybrids between L. esculentum and L. peruvianum. It was found that fluorescence techniques and electron microscopy allowed a distinction to be made between pollen tubes inhibited by a unilateral incompatibility reaction and pollen tubes inhibited by a self-incompatibility reaction, after self-pollination of the hybrids or after reciprocal crossing between the hybrid and the parental species. The observed differences, if real and reliable, demonstrate that unilateral incompatibility in esculentum pollen tubes is governed by a single gametophytic factor which is either linked or allelic to the S-locus. This finding is discussed with reference to recent reports that unilateral incompatibility is controlled, in peruvianum styles, by a number of different dominant genes and it is concluded that these dominant genes, the S-locus of self-incompatibility and the gametophytic factor regulating the unilateral reaction in esculentum pollen belong to the same linkage group. The strong sterility barriers which prevent practically all backcrosses between the hybrid and the parental species were shown to be independent of the factors regulating stylar incompatibility. L. peruvianum is heterozygous for the sterility genes which prevent fertilization or embryo formation when the interspecific hybrid is crossed, as pistillate parent, to different accessions of L. peruvianum. One peruvianum stock was found which, as a pollinator, was highly cross-fertile with the hybrids.The presence of a concentric endoplasmic reticulum in inhibited pollen tubes was observed to be a constant feature of both the self- and the unilateral incompatibility reactions and was interpreted as an indication that incompatibility might lead to a general cessation of protein synthesis. Although incompatible tubes very much resemble, in this respect, the pollen tubes cultured in vitro, it seems probable, on

  13. Cross-cultural barriers to health care.

    Science.gov (United States)

    Vidaeff, Alex C; Kerrigan, Anthony J; Monga, Manju

    2015-01-01

    Culturally sensitive health care represents a real ethical and practical need in a Western healthcare system increasingly serving a multiethnic society. This review focuses on cross-cultural barriers to health care and incongruent aspects from a cultural perspective in the provision of health care. To overcome difficulties in culturally dissimilar interactions and eventually remove cross-cultural barriers to health care, a culturally sensitive physician considers his or her own identity, values, and beliefs; recognizes the similarities and differences among cultures; understands what those similarities and differences mean; and is able to bridge the differences to accomplish clear and effective communication.

  14. Mapping quantitative trait loci (QTLs for fatty acid composition in an interspecific cross of oil palm

    Directory of Open Access Journals (Sweden)

    Sharma Mukesh

    2009-08-01

    Full Text Available Abstract Background Marker Assisted Selection (MAS is well suited to a perennial crop like oil palm, in which the economic products are not produced until several years after planting. The use of DNA markers for selection in such crops can greatly reduce the number of breeding cycles needed. With the use of DNA markers, informed decisions can be made at the nursery stage, regarding which individuals should be retained as breeding stock, which are satisfactory for agricultural production, and which should be culled. The trait associated with oil quality, measured in terms of its fatty acid composition, is an important agronomic trait that can eventually be tracked using molecular markers. This will speed up the production of new and improved oil palm planting materials. Results A map was constructed using AFLP, RFLP and SSR markers for an interspecific cross involving a Colombian Elaeis oleifera (UP1026 and a Nigerian E. guinneensis (T128. A framework map was generated for the male parent, T128, using Joinmap ver. 4.0. In the paternal (E. guineensis map, 252 markers (199 AFLP, 38 RFLP and 15 SSR could be ordered in 21 linkage groups (1815 cM. Interval mapping and multiple-QTL model (MQM mapping (also known as composite interval mapping, CIM were used to detect quantitative trait loci (QTLs controlling oil quality (measured in terms of iodine value and fatty acid composition. At a 5% genome-wide significance threshold level, QTLs associated with iodine value (IV, myristic acid (C14:0, palmitic acid (C16:0, palmitoleic acid (C16:1, stearic acid (C18:0, oleic acid (C18:1 and linoleic acid (C18:2 content were detected. One genomic region on Group 1 appears to be influencing IV, C14:0, C16:0, C18:0 and C18:1 content. Significant QTL for C14:0, C16:1, C18:0 and C18:1 content was detected around the same locus on Group 15, thus revealing another major locus influencing fatty acid composition in oil palm. Additional QTL for C18:0 was detected on Group 3

  15. Comparison of the effects of artificial and natural barriers on large African carnivores: implications for interspecific relationships and connectivity.

    Science.gov (United States)

    Cozzi, Gabriele; Broekhuis, Femke; McNutt, J Weldon; Schmid, Bernhard

    2013-05-01

    1. Physical barriers contribute to habitat fragmentation, influence species distribution and ranging behaviour, and impact long-term population viability. Barrier permeability varies among species and can potentially impact the competitive balance within animal communities by differentially affecting co-occurring species. The influence of barriers on the spatial distribution of species within whole communities has nonetheless received little attention. 2. During a 4-year period, we studied the influence of a fence and rivers, two landscape features that potentially act as barriers on space use and ranging behaviour of lions Panthera leo, spotted hyenas Crocuta crocuta, African wild dogs Lycaon pictus and cheetahs Acinonyx jubatus in Northern Botswana. We compared the tendencies of these species to cross the barriers using data generated from GPS-radio collars fitted to a total of 35 individuals. Barrier permeability was inferred by calculating the number of times animals crossed a barrier vs. the number of times they did not cross. Finally, based on our results, we produced a map of connectivity for the broader landscape system. 3. Permeability varied significantly between fence and rivers and among species. The fence represented an obstacle for lions (permeability = 7.2%), while it was considerably more permeable for hyenas (35.6%) and wild dogs and cheetahs (≥ 50%). In contrast, the rivers and associated floodplains were relatively permeable to lions (14.4%) while they represented a nearly impassable obstacle for the other species (habitat patch on one side of the fence, which might provide a potential refuge for other species. For instance, the competitively inferior wild dogs used this refuge significantly more intensively than the side of the fence with a high presence of lions. 5. We showed that the influence of a barrier on the distribution of animals could potentially result in a broad-scale modification of community structure and ecology within a guild

  16. Crossing safety barriers: influence of children's morphological and functional variables.

    Science.gov (United States)

    Cordovil, Rita; Vieira, Filomena; Barreiros, João

    2012-05-01

    Thirty-three children between 3 and 6 years of age were asked to climb four different types of safety barriers. Morphological and functional variables of the children, which were expected to influence climbing or passing through skills, were collected. The influence of those variables on children's success rate and time to cross was tested. No barrier offered a total restraining efficacy. The horizontal bars barrier was crossed by 97% of the children. In the group of children that succeeded in crossing the four barriers, mean time to cross the most difficult barrier was 15 s. Age was the best predictor for success in crossing most barriers but morphology and strength were important predictors of time to cross. The influence of anthropometric variables in time to cross was dependent upon the characteristics of the barrier. A good design of safety barriers should consider children's age, morphology and strength. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  17. Interspecific cross of the Bactrocera dorsalis Complex (Diptera: Tephritidae): How did it happen?

    International Nuclear Information System (INIS)

    Wee, Suk-Ling; Tan, Keng-Hong

    2000-01-01

    consumption, males of B. papayae and B. carambolae produce a common sex pheromonal component, coniferyl alcohol, CF (Nishida et al. 1988a, Nishida et al. 1988b, Tan and Nishida 1996). Therefore, is CF the sole factor that causes the interspecific attraction before copulation can take place? Secondly, will the acquisition of ME enhance the interspecific mating competitiveness? Lastly, do the females (of these species) show preference for their conspecific males or any males that have ingested ME in their diet and vice versa? The objective of the current investigation was to shed some light on these questions

  18. Genome wide SSR high density genetic map construction from an interspecific cross of Gossypium hirsutum × Gossypium tomentosum

    Directory of Open Access Journals (Sweden)

    Muhammad Kashif Riaz eKhan

    2016-04-01

    Full Text Available A high density genetic map was constructed using F2 population derived from an interspecific cross of G. hirsutum x G. tomentosum. The map consisted of 3,093 marker loci distributed across all the 26 chromosomes and covered 4,365.3 cM of cotton genome with an average inter-marker distance of 1.48 cM. The maximum length of chromosome was 218.38 cM and the minimum was 122.09 cM with an average length of 167.90 cM. A sub-genome covers more genetic distance (2,189.01 cM with an average inter loci distance of 1.53 cM than D sub-genome which covers a length of 2,176.29 cM with an average distance of 1.43 cM. There were 716 distorted loci in the map accounting for 23.14% and most distorted loci were distributed on D sub-genome (25.06%, which were more than on A sub-genome (21.23%. In our map 49 segregation hotspots (SDR were distributed across the genome with more on D sub-genome as compared to A genome. Two post-polyploidization reciprocal translocations of A2/A3 and A4/A5 were suggested by 7 pairs of duplicate loci. The map constructed through these studies is one of the three densest genetic maps in cotton however; this is the first dense genome wide SSR interspecific genetic map between G. hirsutum and G. tomentosum.

  19. Chromosomal rearrangements in interspecific hybrids between Nicotiana gossei Domin and N. tabacum L., obtained by crossing with pollen exposed to helium ion beams or gamma-rays

    International Nuclear Information System (INIS)

    Kitamura, S.; Inoue, M.; Ohmido, N.; Fukui, K.; Tanaka, A.

    2003-01-01

    It is very difficult to obtain interspecific hybrids between Nicotiana tabacum L. (2n=48) and N. gossei Domin (2n=36), because of strong cross incompatibility. We had already obtained interspecific hybrids between these two species, crossing N. gossei flower with N. tabacum pollen exposed to He ions or gamma-rays. Here, we analyze chromosome constitution of these hybrids by genomic in situ hybridization. In root tip cells of the two hybrids obtained with He ion exposure, most mitotic cells contained 18 chromosomes of N. gossei and 24 chromosomes of N. tabacum. However, in some cells, translocations and insertions between parental genomes were observed. On the other hand, in a hybrid obtained by gamma-ray irradiation, intergenomic rearrangements were not observed, although mitotic cells showed 19 hybridization signals with N. gossei DNA in 41 chromosomes. Such chromosomal changes in structure or constitution may be related to overcoming cross incompatibility between these two species

  20. Overcoming interspecific incompatibility in the cross Brassica campestris ssp. japonica x Brassica oleracea var. botrytis using irradiated mentor pollen page

    International Nuclear Information System (INIS)

    Sarla, N.

    1988-01-01

    The cross B. campestris ssp. japonica x B. oleracea var. botrytis fails due to incompatibility barrier at the stigma. To realize this cross, irradiated compatible pollen (mentor pollen) was used before the incompatible pollination. The presence of mentor pollen stimulated the incompatible pollen to germinate and effect fertilization and seed set. One hybrid was thus obtained. Most of the seeds were inviable. Of the 5 plants raised one was a hybrid and 4 resembled the female parent. 1 tab., 7 refs

  1. Early learning affects social dominance: interspecifically cross-fostered tits become subdominant

    OpenAIRE

    Bo Terning Hansen; Tore Slagsvold

    2004-01-01

    Social dominance influences the outcome of competitive interactions over limited resources, and may hence be important for individual fitness. Theory thus predicts that its heritability will be low and that non-genetic determinants of dominance should prevail. In this field experiment we reciprocally cross-fostered great tits (Parus major) to blue tits (Parus caeruleus) to investigate the impact of early social experience on dominance status in competition over food during winter. Controlling...

  2. Performance of Traffic Noise Barriers with Varying Cross-Section

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    Sanja Grubeša

    2011-05-01

    Full Text Available The efficiency of noise barriers largely depends on their geometry. In this paper, the performance of noise barriers was simulated using the numerical Boundary Element Method (BEM. Traffic noise was particularly considered with its standardized noise spectrum adapted to human hearing. The cross-section of the barriers was varied with the goal of finding the optimum shape in comparison to classical rectangular barriers. The barrier performance was calculated at different receiver points for a fixed barrier height and source position. The magnitude of the insertion loss parameter was used to evaluate the performance change, both in one-third octave bands and as the broadband mean insertion loss value. The proposed barriers of varying cross-section were also compared with a typical T-shape barrier of the same height.

  3. An interspecific fungal hybrid reveals cross-kingdom rules for allopolyploid gene expression patterns.

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    Murray P Cox

    2014-03-01

    Full Text Available Polyploidy, a state in which the chromosome complement has undergone an increase, is a major force in evolution. Understanding the consequences of polyploidy has received much attention, and allopolyploids, which result from the union of two different parental genomes, are of particular interest because they must overcome a suite of biological responses to this merger, known as "genome shock." A key question is what happens to gene expression of the two gene copies following allopolyploidization, but until recently the tools to answer this question on a genome-wide basis were lacking. Here we utilize high throughput transcriptome sequencing to produce the first genome-wide picture of gene expression response to allopolyploidy in fungi. A novel pipeline for assigning sequence reads to the gene copies was used to quantify their expression in a fungal allopolyploid. We find that the transcriptional response to allopolyploidy is predominantly conservative: both copies of most genes are retained; over half the genes inherit parental gene expression patterns; and parental differential expression is often lost in the allopolyploid. Strikingly, the patterns of gene expression change are highly concordant with the genome-wide expression results of a cotton allopolyploid. The very different nature of these two allopolyploids implies a conserved, eukaryote-wide transcriptional response to genome merger. We provide evidence that the transcriptional responses we observe are mostly driven by intrinsic differences between the regulatory systems in the parent species, and from this propose a mechanistic model in which the cross-kingdom conservation in transcriptional response reflects conservation of the mutational processes underlying eukaryotic gene regulatory evolution. This work provides a platform to develop a universal understanding of gene expression response to allopolyploidy and suggests that allopolyploids are an exceptional system to investigate gene

  4. Unified Model of Dynamic Forced Barrier Crossing in Single Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Friddle, R W

    2007-06-21

    Thermally activated barrier crossing in the presence of an increasing load can reveal kinetic rate constants and energy barrier parameters when repeated over a range of loading rates. Here we derive a model of the mean escape force for all relevant loading rates--the complete force spectrum. Two well-known approximations emerge as limiting cases; one of which confirms predictions that single-barrier spectra should converge to a phenomenological description in the slow loading limit.

  5. Memory-induced acceleration and slowdown of barrier crossing

    Science.gov (United States)

    Kappler, Julian; Daldrop, Jan O.; Brünig, Florian N.; Boehle, Moritz D.; Netz, Roland R.

    2018-01-01

    We study the mean first-passage time τMFP for the barrier crossing of a single massive particle with non-Markovian memory by Langevin simulations in one dimension. In the Markovian limit of short memory time τΓ, the expected Kramers turnover between the overdamped (high-friction) and the inertial (low-friction) limits is recovered. Compared to the Markovian case, we find barrier crossing to be accelerated for intermediate memory time, while for long memory time, barrier crossing is slowed down and τMFP increases with τΓ as a power law τM F P˜τΓ2. Both effects are derived from an asymptotic propagator analysis: while barrier crossing acceleration at intermediate memory can be understood as an effective particle mass reduction, slowing down for long memory is caused by the slow kinetics of energy diffusion. A simple and globally accurate heuristic formula for τMFP in terms of all relevant time scales of the system is presented and used to establish a scaling diagram featuring the Markovian overdamped and the Markovian inertial regimes, as well as the non-Markovian intermediate memory time regime where barrier crossing is accelerated and the non-Markovian long memory time regime where barrier crossing is slowed down.

  6. Detailed ordering of markers localizing to the Xq26-Xqter region of the human X chromosome by the use of an interspecific Mus spretus mouse cross

    International Nuclear Information System (INIS)

    Avner, P.; Amar, L.; Arnaud, D.; Hanauer, A.; Cambrou, J.

    1987-01-01

    Five probes localizing to the Xq26-Xqter region of the human X chromosome have been genetically mapped on the mouse X chromosome using an interspecific cross involving Mus spretus to a contiguous region lying proximally to the Tabby (Ta) locus. Pedigree and recombinational analysis establish the marker order as being Hprt-FIX-c11-G6PD-St14-1. The size of this contiguous region is such that the X-linked muscular dystrophy (mdx) mouse mutation probably maps within this segment. This in turn suggests that it is highly improbable that the mouse mdx locus represents a model for Duchenne muscular dystrophy (DMD). It is, however, compatible with the idea that this mutation may correspond in man to Emery Dreifuss muscular dystrophy. The high frequency of restriction fragment length polymorphisms found in this interspecific system for all the human cross-reacting probes examined up until now, using only a limited number of restriction enzymes, suggests that the Mus spretus mapping system may be of great potential value for establishing the linkage relationships existing in man when conserved chromosomal regions are concerned and human/mouse cross-reacting probes are available or can be obtained

  7. Achieving Crossed Strong Barrier Coverage in Wireless Sensor Network.

    Science.gov (United States)

    Han, Ruisong; Yang, Wei; Zhang, Li

    2018-02-10

    Barrier coverage has been widely used to detect intrusions in wireless sensor networks (WSNs). It can fulfill the monitoring task while extending the lifetime of the network. Though barrier coverage in WSNs has been intensively studied in recent years, previous research failed to consider the problem of intrusion in transversal directions. If an intruder knows the deployment configuration of sensor nodes, then there is a high probability that it may traverse the whole target region from particular directions, without being detected. In this paper, we introduce the concept of crossed barrier coverage that can overcome this defect. We prove that the problem of finding the maximum number of crossed barriers is NP-hard and integer linear programming (ILP) is used to formulate the optimization problem. The branch-and-bound algorithm is adopted to determine the maximum number of crossed barriers. In addition, we also propose a multi-round shortest path algorithm (MSPA) to solve the optimization problem, which works heuristically to guarantee efficiency while maintaining near-optimal solutions. Several conventional algorithms for finding the maximum number of disjoint strong barriers are also modified to solve the crossed barrier problem and for the purpose of comparison. Extensive simulation studies demonstrate the effectiveness of MSPA.

  8. Hybrid Weakness Found in the Backcross Progeny of an Inter-Specific Cross of Oryza Sativa / O. Glumaepatula

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    Sobrizal

    2009-01-01

    Full Text Available Hybrid breakdown expressed as sterility or weakness or both in F2 or later generations is considered to be a reproductive barrier between two distantly related taxa. Hybrid breakdown that showed poor growth habit with fertile seeds was found in the backcross progenies (BC4F2 which were derived from a cross between a cultivated rice Oryza sativa L. cv. Taichung 65 and a wild rice Oryza glumaepatula Steud (Acc. IRGC 105668 where Taichung 65 was used as a recurrent parent. Through segregation analysis of BC4F2 population, a novel gene for weakness was identified, and this gene was designated as hwf1 (hybrid weakness f-1. RFLP (Restriction Fragment Length Polymorphism analysis was employed to determine the chromosomal location of hwf1 gene. The result revealed that hwf1 was located between G3006 and C933 RFLP markers, with map distances of 0.5 cM and 1.9 cM, respectively, and co-segregated with C708, C820, and R288 on the short arm of chromosome 4. Since both O. glumaepatula (Acc. IRGC 105668 and Taichung 65 that was used as parents showed normal growth habit, the weakness in this study was assumed to be controlled by a set of complementary recessive genes. One of the complementary genes is hwf1 from O. glumaepatula, and another gene should be from Taichung 65, because the genetic background of the BC4F2 populations that were used for analysis is Taichung 65. The gene from Taichung 65 has not been identified yet, therefore, it is necessary to conduct the experiment for finding out the complement of hwf1 gene in near future.

  9. Hybrid Weakness Found In the Backcross Progeny of an Inter-Specific Cross of Oryza Sativa / O. Glumaepatula

    International Nuclear Information System (INIS)

    Sobrizal; Yoshimura, A

    2009-01-01

    Hybrid breakdown expressed as sterility or weakness or both in F 2 or later generations is considered to be a reproductive barrier between two distantly related taxa. Hybrid breakdown that showed poor growth habit with fertile seeds was found in the backcross progenies (BC 4 F 2 ) which were derived from a cross between a cultivated rice Oryza sativa L. cv. Taichung 65 and a wild rice Oryza glumaepatula Steud (Acc. IRGC 105668) where Taichung 65 was used as a recurrent parent. Through segregation analysis of BC 4 F 2 population, a novel gene for weakness was identified, and this gene was designated as hwf1 (hybrid weakness f-1). RFLP (Restriction Fragment Length Polymorphism) analysis was employed to determine the chromosomal location of hwf1 gene. The result revealed that hwf1 was located between G3006 and C933 RFLP markers, with map distances of 0.5 cM and 1.9 cM, respectively, and co-segregated with C708, C820, and R288 on the short arm of chromosome 4. Since both O. glumaepatula (Acc. IRGC 105668) and Taichung 65 that was used as parents showed normal growth habit, the weakness in this study was assumed to be controlled by a set of complementary recessive genes. One of the complementary genes is hwf1 from O. glumaepatula, and another gene should be from Taichung 65, because the genetic background of the BC 4 F 2 populations that were used for analysis is Taichung 65. The gene from Taichung 65 has not been identified yet, therefore, it is necessary to conduct the experiment for finding out the complement of hwf1 gene in near future. (author)

  10. CORRIDOR-TYPE BAFFLED MIXING BASIN WITH CROSS POROUS BARRIERS

    Directory of Open Access Journals (Sweden)

    S. M. Epoyan

    2018-02-01

    Full Text Available Purpose. The paper hightlights the increase in operational efficiency of corridor-type baffled mixing basin by installing of cross porous barriers made of gravel (or other materials and epoxy resin, grade ED-20 (ED-16 with the hardener polyethylenepolyamine (PEPA, approved by Ukrainian Ministry of Health in systems of utility and drinking water supply. Methodology. The first stage of the experiments was performed on the model of the proposed mixer in scale 1:4 in order to determine the local resistance of the porous barrier, which is made of gravel with a size of 10-15 mm (average diameter 12.5 mm and thickness of 50 mm. The local resistance of the barrier was measured using piezometers installed before and after the porous barrier. The velocity of water motion in the corridor of the mixer was determined depending on the water consumption, incoming on the mixer accordingly to the water meter and by the volumetric method. Findings. In accordance with researches when the water flows at a velocity of 0.1 m/s in the corridor of the mixer, the head losses in the porous barrier is 17 cm (0.17 m, and at a velocity of 0.2 m/s–0.68 m. The resistance coefficient (ξ, which is equal to 333.2 for the investigated barrier, was determined experimentally. It allows determining the head losses in the porous barrier at other velocities of water motion. When the velocity of water motion in the corridors of the mixer is from 0.7 up to 0.5 m/s, head losses increase almost fourfold. The conducted researches allowed to develop a calculation methodology for corridor-type baffled mixing basin with porous polymer-concrete barriers. Originality. Authors developed and investigated the corridor-type baffled mixing basin with porous polymer-concrete barriers. These barriers allow increasing and regulating the intensity and time of reagents mixing with the initial water exactly in the barriers, improving the distribution of the flow through the section of the mixer

  11. Interspecific Hybridization May Provide Novel Opportunities for Coral Reef Restoration

    Directory of Open Access Journals (Sweden)

    Wing Yan Chan

    2018-05-01

    Full Text Available Climate change and other anthropogenic disturbances have created an era characterized by the inability of most ecosystems to maintain their original, pristine states, the Anthropocene. Investigating new and innovative strategies that may facilitate ecosystem restoration is thus becoming increasingly important, particularly for coral reefs around the globe which are deteriorating at an alarming rate. The Great Barrier Reef (GBR lost half its coral cover between 1985 and 2012, and experienced back-to-back heat-induced mass bleaching events and high coral mortality in 2016 and 2017. Here we investigate the efficacy of interspecific hybridization as a tool to develop coral stock with enhanced climate resilience. We crossed two Acropora species pairs from the GBR and examined several phenotypic traits over 28 weeks of exposure to ambient and elevated temperature and pCO2. While elevated temperature and pCO2 conditions negatively affected size and survival of both purebreds and hybrids, higher survival and larger recruit size were observed in some of the hybrid offspring groups under both ambient and elevated conditions. Further, interspecific hybrids had high fertilization rates, normal embryonic development, and similar Symbiodinium uptake and photochemical efficiency as purebred offspring. While the fitness of these hybrids in the field and their reproductive and backcrossing potential remain to be investigated, current findings provide proof-of-concept that interspecific hybridization may produce genotypes with enhanced climate resilience, and has the potential to increase the success of coral reef restoration initiatives.

  12. Triploid Production from Interspecific Crosses of Two Diploid Perennial Helianthus with Diploid Cultivated Sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Liu, Zhao; Seiler, Gerald J; Gulya, Thomas J; Feng, Jiuhuan; Rashid, Khalid Y; Cai, Xiwen; Jan, Chao-Chien

    2017-04-03

    Wild Helianthus species are a valuable genetic resource for the improvement of cultivated sunflower. We report the discovery and characterization of a unique high frequency production of triploids when cultivated sunflower was pollinated by specific accessions of diploid Helianthus nuttallii T. & G. and H. maximiliani Schr. Genomic in situ hybridization (GISH) analyses indicated that the triploid F 1 s had two genomes from the wild pollen sources and one from the cultivated line. Mitotic chromosome analyses indicated that the frequency of triploid progenies from the crosses of cultivated lines × H. nuttallii accession 102 (N102) was significantly higher than those of unexpected polyploid progenies from the crosses of wild perennial species × N102, and no unexpected polyploids were obtained from the reverse crosses. Pollen stainability analysis suggested the existence of a low percentage of unreduced (2 n ) male gametes in some accessions, especially N102 and H. maximiliani accession 1113 (M1113), which were generated at the telophase II and tetrad stages of meiosis. The triploid F 1 s could be the results of preferred fertilization of the low frequency of 2 n male gametes with the female gametes of the cultivated sunflower, due to the dosage factors related to recognition and rejection of foreign pollen during fertilization. The triploids have been used to produce amphiploids and aneuploids. Future studies of the male gametes' fate from pollination through fertilization will further uncover the mechanism of this whole genome transmission. Studies of the genetic control of this trait will facilitate research on sunflower polyploidy speciation and evolution, and the utilization of this trait in sunflower breeding. Copyright © 2017 Liu et al.

  13. Accelerated Senescence and Enhanced Disease Resistance in Hybrid Chlorosis Lines Derived from Interspecific Crosses between Tetraploid Wheat and Aegilops tauschii

    Science.gov (United States)

    Tosa, Yukio; Yoshida, Kentaro; Park, Pyoyun; Takumi, Shigeo

    2015-01-01

    Hybrid chlorosis, a type of hybrid incompatibility, has frequently been reported in inter- and intraspecific crosses of allopolyploid wheat. In a previous study, we reported some types of growth abnormalities such as hybrid necrosis and observed hybrid chlorosis with mild or severe abnormalities in wheat triploids obtained in crosses between tetraploid wheat cultivar Langdon and four Ae. tauschii accessions and in their derived synthetic hexaploids. However, the molecular mechanisms underlying hybrid chlorosis are not well understood. Here, we compared cytology and gene expression in leaves to characterize the abnormal growth in wheat synthetics showing mild and severe chlorosis. In addition, we compared disease resistance to wheat blast fungus. In total 55 and 105 genes related to carbohydrate metabolism and 53 and 89 genes for defense responses were markedly up-regulated in the mild and severe chlorosis lines, respectively. Abnormal chloroplasts formed in the mesophyll cells before the leaves yellowed in the hybrid chlorosis lines. The plants with mild chlorosis showed increased resistance to wheat blast and powdery mildew fungi, although significant differences only in two, third internode length and maturation time, out of the examined agricultural traits were found between the wild type and plants showing mild chlorosis. These observations suggest that senescence might be accelerated in hybrid chlorosis lines of wheat synthetics. Moreover, in wheat synthetics showing mild chlorosis, the negative effects on biomass can be minimized, and they may show substantial fitness under pathogen-polluted conditions. PMID:25806790

  14. Accelerated senescence and enhanced disease resistance in hybrid chlorosis lines derived from interspecific crosses between tetraploid wheat and Aegilops tauschii.

    Directory of Open Access Journals (Sweden)

    Hiroki Nakano

    Full Text Available Hybrid chlorosis, a type of hybrid incompatibility, has frequently been reported in inter- and intraspecific crosses of allopolyploid wheat. In a previous study, we reported some types of growth abnormalities such as hybrid necrosis and observed hybrid chlorosis with mild or severe abnormalities in wheat triploids obtained in crosses between tetraploid wheat cultivar Langdon and four Ae. tauschii accessions and in their derived synthetic hexaploids. However, the molecular mechanisms underlying hybrid chlorosis are not well understood. Here, we compared cytology and gene expression in leaves to characterize the abnormal growth in wheat synthetics showing mild and severe chlorosis. In addition, we compared disease resistance to wheat blast fungus. In total 55 and 105 genes related to carbohydrate metabolism and 53 and 89 genes for defense responses were markedly up-regulated in the mild and severe chlorosis lines, respectively. Abnormal chloroplasts formed in the mesophyll cells before the leaves yellowed in the hybrid chlorosis lines. The plants with mild chlorosis showed increased resistance to wheat blast and powdery mildew fungi, although significant differences only in two, third internode length and maturation time, out of the examined agricultural traits were found between the wild type and plants showing mild chlorosis. These observations suggest that senescence might be accelerated in hybrid chlorosis lines of wheat synthetics. Moreover, in wheat synthetics showing mild chlorosis, the negative effects on biomass can be minimized, and they may show substantial fitness under pathogen-polluted conditions.

  15. Crossing the entropy barrier of dynamical zeta functions

    International Nuclear Information System (INIS)

    Aurich, R.; Bolte, J.; Matthies, C.; Sieber, M.; Steiner, F.

    1992-01-01

    Dynamical zeta functions are an important tool to quantize chaotic dynamical systems. The basic quantization rules require the computation of the zeta functions on the real energy axis, where the Euler product representations running over the classical periodic orbits usually do not converge due to the existence of the so-called entropy barrier determined by the topological entropy of the classical system. We shown that the convergence properties of the dynamical zeta functions rewritten as Dirichlet series are governed not only by the well-known topological and metric entropy, but depend crucially on subtle statistical properties of the Maslow indices and of the multiplicities of the periodic orbits that are measured by a new parameter for which we introduce the notion of a third entropy. If and only if the third entropy is nonvanishing, one can cross the entropy barrier; if it exceeds a certain value, one can even compute the zeta function in the physical region by means of a convergent Dirichlet series. A simple statistical model is presented which allows to compute the third entropy. Four examples of chaotic systems are studied in detail to test the model numerically. (orig.)

  16. Crossing the entropy barrier of dynamical zeta functions

    Energy Technology Data Exchange (ETDEWEB)

    Aurich, R.; Bolte, J.; Matthies, C.; Sieber, M.; Steiner, F. (Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik)

    1992-01-01

    Dynamical zeta functions are an important tool to quantize chaotic dynamical systems. The basic quantization rules require the computation of the zeta functions on the real energy axis, where the Euler product representations running over the classical periodic orbits usually do not converge due to the existence of the so-called entropy barrier determined by the topological entropy of the classical system. We shown that the convergence properties of the dynamical zeta functions rewritten as Dirichlet series are governed not only by the well-known topological and metric entropy, but depend crucially on subtle statistical properties of the Maslow indices and of the multiplicities of the periodic orbits that are measured by a new parameter for which we introduce the notion of a third entropy. If and only if the third entropy is nonvanishing, one can cross the entropy barrier; if it exceeds a certain value, one can even compute the zeta function in the physical region by means of a convergent Dirichlet series. A simple statistical model is presented which allows to compute the third entropy. Four examples of chaotic systems are studied in detail to test the model numerically. (orig.).

  17. Genetic relationships between interspecific lines derived from Oryza glaberrima and Oryza sativa crosses using microsatellites and agro-morphological markers

    Energy Technology Data Exchange (ETDEWEB)

    Moukoumbi, Y.D.; Kolade, O.; Drame, K.N.; Sie, M.; Ndjiondjo, M.N.

    2015-07-01

    New Rice(s) for Africa (NERICA) are high yielding rice varieties mostly cultivated in Sub-Saharan Africa and developed by the Africa Rice Center. This study is aimed at investigating the proportion of introgression of parental genomic contribution of 60 lowland NERICA varieties and establishment of molecular profiling. Agro-morphological data from 17 characteristics was recorded and significant (p<0.05) to high significant (p<0.0001) differences were obtained with leaf length and width, plant height at maturity, days to heading, maturity, primary and secondary branching of panicles, and grain width and grain thickness. A total of 114 microsatellite polymorphic markers covering 2183.13 cM of the rice genome showed the proportions of alleles introgressed from the donor parent (Oryza glaberrima) into 52 lowland NERICA lines (TOG5681 and IR64) as follows: 11% for BC2, 6.07% for BC3, and 7.55% for BC4. The introgression proportions for the eight remaining lowland NERICA lines derived from other crosses ranged from 5.5 to 11.3%. The proportion recorded with the recurrent parent was 83.99%. The highest introgression proportions of the O. glaberrima allele for all 60 lowland NERICA lines were found on chromosomes 2, 6 and 12 (TOG5681/IR64) and on chromosome 3 with NERIC-L-29 (TOG5681/IR1529-680-3-2). Multivariate analyses performed using an association of agro-morphological and molecular data revealed two major groups according to the distribution of the lowland NERICAs including the lowland NERICAs released were found in cluster 1 of the dendrogram. Genetic and genomic studies, QTL identification and analysis using agro-morphologically significant traits revealed should be used to develop mega-varieties adapted in rice growth conditions in Sub-Saharan Africa. (Author)

  18. Synthesis and characterization of interspecific trigenomic hybrids ...

    African Journals Online (AJOL)

    Jane

    2011-09-28

    Sep 28, 2011 ... Interspecific reciprocal crosses between three cultivated Brassica ... environmental conditions, which impacts the qualitative and quantitative crop and oil production to a greater extent. ... Brassica rapa L. (2n= 20, AA) (Nanda Kumar et al., 1991; ... breeding potential for the crop brassicas as a trigenomic.

  19. Genetic Diversity and Phenotypic Variation in an Introgression Line Population Derived from an Interspecific Cross between Oryza glaberrima and Oryza sativa.

    Directory of Open Access Journals (Sweden)

    Caijin Chen

    Full Text Available The introduction of closely related species genomic fragments is an effective way to enrich genetic diversity and creates new germplasms in crops. Here, we studied the genetic diversity of an introgression line (IL population composed of 106 ILs derived from an interspecific tetra cross between O. glaberrima and O. sativa (RAM3/Jin23B//Jin23B///YuetaiB. The proportion of O. glaberrima genome (PGG in the ILs ranged from 0.3% to 36.7%, with an average value of 12.32% which is close to the theoretically expected proportion. A total of 250 polymorphic alleles were amplified by 21 AFLP primer combinations with an average of 12 alleles per primer. Population structure analysis revealed that the IL population can be divided into four genetically distinct subpopulations. Both principal component analysis and neighbor-joining tree analysis showed that ILs with a higher PGG displayed greater genetic diversity. Canonical discriminant analysis identified six phenotypic traits (plant height, yield per plant, filled grain percentage, panicle length, panicle number and days to flowering as the main discriminatory traits among the ILs and between the subpopulations and showed significant phenotypic distances between subpopulations. The effects of PGG on phenotypic traits in the ILs were estimated using a linear admixed model, which showed a significant positive effect on grain yield per plant (0.286±0.117, plant height (0.418 ± 0.132, panicle length (0.663 ± 0.107, and spikelet number per panicle (0.339 ± 0.128, and a significant negative effect on filled grain percentage (-0.267 ± 0.123 and days to flowering (-0.324 ± 0.075. We found that an intermediate range (10% - 20% of PGG was more effective for producing ILs with favorable integrated agronomic traits. Our results confirm that construction of IL population carrying O. glaberrima genomic fragments could be an effective approach to increase the genetic diversity of O. sativa genome and an appropriate

  20. Reproductive characterization of interspecific hybrids among Capsicum species

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo da Silva Monteiro

    2011-01-01

    Full Text Available The objective of this study was the reproductive characterization of Capsicum accessions as well as of interspecifichybrids, based on pollen viability. Hybrids were obtained between Capsicum species. Pollen viability was high in most accessions,indicating that meiosis is normal, resulting in viable pollen grains. The pollen viability of species C. pubescens was the lowest (27%. The interspecific hybrids had varying degrees of pollen viability, from fertile combinations (C. chinense x C. frutescens and C.annuum x C. baccatum to male sterile combinations. Pollen viability also varied within the hybrid combination according toaccessions used in the cross. Results indicate that male sterility is one of the incompatibility barriers among Capsicum species sincehybrids can be established, but may be male sterile.

  1. [Blood-brain barrier part III: therapeutic approaches to cross the blood-brain barrier and target the brain].

    Science.gov (United States)

    Weiss, N; Miller, F; Cazaubon, S; Couraud, P-O

    2010-03-01

    Over the last few years, the blood-brain barrier has come to be considered as the main limitation for the treatment of neurological diseases caused by inflammatory, tumor or neurodegenerative disorders. In the blood-brain barrier, the close intercellular contact between cerebral endothelial cells due to tight junctions prevents the passive diffusion of hydrophilic components from the bloodstream into the brain. Several specific transport systems (via transporters expressed on cerebral endothelial cells) are implicated in the delivery of nutriments, ions and vitamins to the brain; other transporters expressed on cerebral endothelial cells extrude endogenous substances or xenobiotics, which have crossed the cerebral endothelium, out of the brain and into the bloodstream. Recently, several strategies have been proposed to target the brain, (i) by by-passing the blood-brain barrier by central drug administration, (ii) by increasing permeability of the blood-brain barrier, (iii) by modulating the expression and/or the activity of efflux transporters, (iv) by using the physiological receptor-dependent blood-brain barrier transport, and (v) by creating new viral or chemical vectors to cross the blood-brain barrier. This review focuses on the illustration of these different approaches. Copyright (c) 2009 Elsevier Masson SAS. All rights reserved.

  2. The effect of pH on hydrolysis, cross-linking and barrier properties of starch barriers containing citric acid.

    Science.gov (United States)

    Olsson, Erik; Menzel, Carolin; Johansson, Caisa; Andersson, Roger; Koch, Kristine; Järnström, Lars

    2013-11-06

    Citric acid cross-linking of starch for e.g. food packaging applications has been intensely studied during the last decade as a method of producing water-insensitive renewable barrier coatings. We managed to improve a starch formulation containing citric acid as cross-linking agent for industrial paper coating applications by adjusting the pH of the starch solution. The described starch formulations exhibited both cross-linking of starch by citric acid as well as satisfactory barrier properties, e.g. fairly low OTR values at 50% RH that are comparable with EVOH. Furthermore, it has been shown that barrier properties of coated papers with different solution pH were correlated to molecular changes in starch showing both hydrolysis and cross-linking of starch molecules in the presence of citric acid. Hydrolysis was shown to be almost completely hindered at solution pH≥4 at curing temperatures≤105 °C and at pH≥5 at curing temperatures≤150 °C, whereas cross-linking still occurred to some extent at pH≤6.5 and drying temperatures as low as 70 °C. Coated papers showed a minimum in water vapor transmission rate at pH 4 of the starch coating solution, corresponding to the point where hydrolysis was effectively hindered but where a significant degree of cross-linking still occurred. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. 6,7Li + 28Si total reaction cross sections at near barrier energies

    International Nuclear Information System (INIS)

    Pakou, A.; Musumarra, A.; Pierroutsakou, D.; Alamanos, N.; Assimakopoulos, P.A.; Divis, N.; Doukelis, G.; Gillibert, A.; Harissopulos, S.; Kalyva, G.; Kokkoris, M.; Lagoyannis, A.; Mertzimekis, T.J.; Nicolis, N.G.; Papachristodoulou, C.; Perdikakis, G.; Roubos, D.; Rusek, K.; Spyrou, S.; Zarkadas, Ch.

    2007-01-01

    Total reaction cross section measurements for the 6,7 Li + 28 Si systems have been performed at near-barrier energies. The results indicate that, with respect to the potential anomaly at barrier, 6 Li and 7 Li on light targets exhibit similar energy dependence on the imaginary potential. Comparisons are made with 6,7 Li cross sections on light and heavy targets, extracted via previous elastic scattering measurements and also with CDCC calculations. Energy dependent parametrisations are also obtained for total reaction cross sections of 6,7 Li on Si, as well as on any target, at near barrier energies

  4. Fine-mapping and cross-validation of QTLs linked to fatty acid composition in multiple independent interspecific crosses of oil palm.

    Science.gov (United States)

    Ting, Ngoot-Chin; Yaakub, Zulkifli; Kamaruddin, Katialisa; Mayes, Sean; Massawe, Festo; Sambanthamurthi, Ravigadevi; Jansen, Johannes; Low, Leslie Eng Ti; Ithnin, Maizura; Kushairi, Ahmad; Arulandoo, Xaviar; Rosli, Rozana; Chan, Kuang-Lim; Amiruddin, Nadzirah; Sritharan, Kandha; Lim, Chin Ching; Nookiah, Rajanaidu; Amiruddin, Mohd Din; Singh, Rajinder

    2016-04-14

    The commercial oil palm (Elaeis guineensis Jacq.) produces a mesocarp oil (commonly called 'palm oil') with approximately equal proportions of saturated and unsaturated fatty acids (FAs). An increase in unsaturated FAs content or iodine value (IV) as a measure of the degree of unsaturation would help to open up new markets for the oil. One way to manipulate the fatty acid composition (FAC) in palm oil is through introgression of favourable alleles from the American oil palm, E. oleifera, which has a more unsaturated oil. In this study, a segregating E. oleifera x E. guineensis (OxG) hybrid population for FAC is used to identify quantitative trait loci (QTLs) linked to IV and various FAs. QTL analysis revealed 10 major and two putative QTLs for IV and six FAs, C14:0, C16:0, C16:1, C18:0, C18:1 and C18:2 distributed across six linkage groups (LGs), OT1, T2, T3, OT4, OT6 and T9. The major QTLs for IV and C16:0 on LGOT1 explained 60.0 - 69.0 % of the phenotypic trait variation and were validated in two independent BC2 populations. The genomic interval contains several key structural genes in the FA and oil biosynthesis pathways such as PATE/FATB, HIBCH, BASS2, LACS4 and DGAT1 and also a relevant transcription factor (TF), WRI1. The literature suggests that some of these genes can exhibit pleiotropic effects in the regulatory networks of these traits. Using the whole genome sequence data, markers tightly linked to the candidate genes were also developed. Clustering trait values according to the allelic forms of these candidate markers revealed significant differences in the IV and FAs of the palms in the mapping and validation crosses. The candidate gene approach described and exploited here is useful to identify the potential causal genes linked to FAC and can be adopted for marker-assisted selection (MAS) in oil palm.

  5. Barrier and mechanical properties of plasticized and cross-linked nanocellulose coatings for paper packaging applications

    OpenAIRE

    Herrera, M. A. (Martha A.); Mathew, A. P. (Aji P.); Oksman, K. (Kristiina)

    2017-01-01

    Abstract Barrier, mechanical and thermal properties of porous paper substrates dip-coated with nanocellulose (NC) were studied. Sorbitol plasticizer was used to improve the toughness, and citric acid cross-linker to improve the moisture stability of the coatings. In general, the addition of sorbitol increased the barrier properties, maximum strength and toughness as well as the thermal stability of the samples when compared to the non-modified NC coatings. The barrier properties significan...

  6. Microscopic calculation of sub-barrier fusion cross section and barrier distribution using M3Y-type forces

    International Nuclear Information System (INIS)

    Ismail, M.; Ramadan, Kh.A.

    2000-01-01

    The heavy-ion (HI) potential between spherical and deformed nuclei is derived using an M3Y-type nucleon-nucleon (NN) interaction. The calculation of the exchange part of the HI potential was improved by using a finite-range NN exchange force instead of the zero-range pseudo-potential which is usually used in deriving the potential between deformed nuclei. We consider an 154 Sm- 16 O nuclear pair as an example to show the effect of finite range on the nucleus-nucleus potential for different deformation parameters and at different orientation angles of the deformed target nucleus. We calculated the fusion cross section and the barrier distribution in the WKB approximation and studied their dependence on the orientation and deformation of the target nucleus. The variations found due to improving the exchange part enhance the fusion cross section below the Coulomb barrier by a factor of about four. It has been found that both the cross section and the barrier distribution are very sensitive to the deformation parameters at energies below the Coulomb barrier. (author)

  7. Microscopic calculation of sub-barrier fusion cross section and barrier distribution using M3Y-type forces

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, M.; Ramadan, Kh.A. [Physics Department, Faculty of Science, Cairo University, Giza (Egypt)

    2000-10-01

    The heavy-ion (HI) potential between spherical and deformed nuclei is derived using an M3Y-type nucleon-nucleon (NN) interaction. The calculation of the exchange part of the HI potential was improved by using a finite-range NN exchange force instead of the zero-range pseudo-potential which is usually used in deriving the potential between deformed nuclei. We consider an {sup 154}Sm-{sup 16}O nuclear pair as an example to show the effect of finite range on the nucleus-nucleus potential for different deformation parameters and at different orientation angles of the deformed target nucleus. We calculated the fusion cross section and the barrier distribution in the WKB approximation and studied their dependence on the orientation and deformation of the target nucleus. The variations found due to improving the exchange part enhance the fusion cross section below the Coulomb barrier by a factor of about four. It has been found that both the cross section and the barrier distribution are very sensitive to the deformation parameters at energies below the Coulomb barrier. (author)

  8. Viscosity-Induced Crossing of the Phantom Barrier

    Directory of Open Access Journals (Sweden)

    Iver Brevik

    2015-09-01

    Full Text Available We show explicitly, by using astrophysical data plus reasonable assumptions for the bulk viscosity in the cosmic fluid, how the magnitude of this viscosity may be high enough to drive the fluid from its position in the quintessence region at present time t = 0 across the barrier w = −1 into the phantom region in the late universe. The phantom barrier is accordingly not a sharp mathematical divide, but rather a fuzzy concept. We also calculate the limiting forms of various thermodynamical quantities, including the rate of entropy production, for a dark energy fluid near the future Big Rip singularity.

  9. Simple Sequence Repeat (SSR Genetic Linkage Map of D Genome Diploid Cotton Derived from an Interspecific Cross between Gossypium davidsonii and Gossypium klotzschianum

    Directory of Open Access Journals (Sweden)

    Joy Nyangasi Kirungu

    2018-01-01

    Full Text Available The challenge in tetraploid cotton cultivars is the narrow genetic base and therefore, the bottleneck is how to obtain interspecific hybrids and introduce the germplasm directly from wild cotton to elite cultivars. Construction of genetic maps has provided insight into understanding the genome structure, interrelationships between organisms in relation to evolution, and discovery of genes that carry important agronomic traits in plants. In this study, we generated an interspecific hybrid between two wild diploid cottons, Gossypium davidsonii and Gossypium klotzschianum, and genotyped 188 F2:3 populations in order to develop a genetic map. We screened 12,560 SWU Simple Sequence Repeat (SSR primers and obtained 1000 polymorphic markers which accounted for only 8%. A total of 928 polymorphic primers were successfully scored and only 728 were effectively linked across the 13 chromosomes, but with an asymmetrical distribution. The map length was 1480.23 cM, with an average length of 2.182 cM between adjacent markers. A high percentage of the markers on the map developed, and for the physical map of G. raimondii, exhibited highly significant collinearity, with two types of duplication. High level of segregation distortion was observed. A total of 27 key genes were identified with diverse roles in plant hormone signaling, development, and defense reactions. The achievement of developing the F2:3 population and its genetic map constructions may be a landmark in establishing a new tool for the genetic improvement of cultivars from wild plants in cotton. Our map had an increased recombination length compared to other maps developed from other D genome cotton species.

  10. Does sumatriptan cross the blood-brain barrier in animals and man?

    DEFF Research Database (Denmark)

    Tfelt-Hansen, Peer

    2010-01-01

    Sumatriptan, a relatively hydrophilic triptan, based on several animal studies has been regarded to be unable to cross the blood-brain barrier (BBB). In more recent animal studies there are strong indications that sumatriptan to some extent can cross the BBB. The CNS adverse events of sumatriptan...

  11. Crossing the Barriers: An Analysis of Land Access Barriers to Geothermal Development and Potential Improvement Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Levine, Aaron L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Young, Katherine R [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-10-04

    Developers have identified many non-technical barriers to geothermal power development, including access to land. Activities required for accessing land, such as environmental review and private and public leasing can take a considerable amount of time and can delay or prevent project development. This paper discusses the impacts to available geothermal resources and deployment caused by land access challenges, including tribal and cultural resources, environmentally sensitive areas, biological resources, land ownership, federal and state lease queues, and proximity to military installations. In this analysis, we identified challenges that have the potential to prevent development of identified and undiscovered hydrothermal geothermal resources. We found that an estimated 400 MW of identified geothermal resource potential and 4,000 MW of undiscovered geothermal resource potential were either unallowed for development or contained one or more significant barriers that could prevent development at the site. Potential improvement scenarios that could be employed to overcome these barriers include (1) providing continuous funding to the U.S. Forest Service (USFS) for processing geothermal leases and permit applications and (2) the creation of advanced environmental mitigation measures. The model results forecast that continuous funding to the USFS could result in deployment of an additional 80 MW of geothermal capacity by 2030 and 124 MW of geothermal capacity by 2050 when compared to the business-as-usual scenario. The creation of advanced environmental mitigation measures coupled with continuous funding to the USFS could result in deployment of an additional 97 MW of geothermal capacity by 2030 and 152 MW of geothermal capacity by 2050 when compared to the business-as-usual scenario. The small impact on potential deployment in these improvement scenarios suggests that these 4,400 MW have other barriers to development in addition to land access. In other words, simply

  12. A cross-cultural investigation into the dimensional structure and stability of the Barriers to Research and Utilization Scale (BARRIERS Scale).

    Science.gov (United States)

    Williams, Brett; Brown, Ted; Costello, Shane

    2015-10-24

    It is important that scales exhibit strong measurement properties including those related to the investigation of issues that impact evidence-based practice. The validity of the Barriers to Research Utilization Scale (BARRIERS Scale) has recently been questioned in a systematic review. This study investigated the dimensional structure and stability of the 28 item BARRIERS Scale when completed by three groups of participants from three different cross-cultural environments. Data from the BARRIERS Scale completed by 696 occupational therapists from Australia (n = 137), Taiwan (n = 413), and the United Kingdom (n = 144) were analysed using principal components analysis, followed by Procrustes Transformation. Poorly fitting items were identified by low communalities, cross-loading, and theoretically inconsistent primary loadings, and were systematically removed until good fit was achieved. The cross-cultural stability of the component structure of the BARRIERS Scale was examined. A four component, 19 item version of the BARRIERS Scale emerged that demonstrated an improved dimensional fit and stability across the three participant groups. The resulting four components were consistent with the BARRIERS Scale as originally conceptualised. Findings from the study suggest that the four component, 19 item version of the BARRIERS Scale is a robust and valid measure for identifying barriers to research utilization for occupational therapists in paediatric health care settings across Australia, United Kingdom, and Taiwan. The four component 19 item version of the BARRIERS Scale exhibited good dimensional structure, internal consistency, and stability.

  13. Direct Visualization of Barrier Crossing Dynamics in a Driven Optical Matter System.

    Science.gov (United States)

    Figliozzi, Patrick; Peterson, Curtis W; Rice, Stuart A; Scherer, Norbert F

    2018-04-25

    A major impediment to a more complete understanding of barrier crossing and other single-molecule processes is the inability to directly visualize the trajectories and dynamics of atoms and molecules in reactions. Rather, the kinetics are inferred from ensemble measurements or the position of a transducer ( e. g., an AFM cantilever) as a surrogate variable. Direct visualization is highly desirable. Here, we achieve the direct measurement of barrier crossing trajectories by using optical microscopy to observe position and orientation changes of pairs of Ag nanoparticles, i. e. passing events, in an optical ring trap. A two-step mechanism similar to a bimolecular exchange reaction or the Michaelis-Menten scheme is revealed by analysis that combines detailed knowledge of each trajectory, a statistically significant number of repetitions of the passing events, and the driving force dependence of the process. We find that while the total event rate increases with driving force, this increase is due to an increase in the rate of encounters. There is no drive force dependence on the rate of barrier crossing because the key motion for the process involves a random (thermal) radial fluctuation of one particle allowing the other to pass. This simple experiment can readily be extended to study more complex barrier crossing processes by replacing the spherical metal nanoparticles with anisotropic ones or by creating more intricate optical trapping potentials.

  14. Genetic Confirmation of Mungbean (Vigna radiata) and Mashbean (Vigna mungo) Interspecific Recombinants using Molecular Markers.

    Science.gov (United States)

    Abbas, Ghulam; Hameed, Amjad; Rizwan, Muhammad; Ahsan, Muhammad; Asghar, Muhammad J; Iqbal, Nayyer

    2015-01-01

    Molecular confirmation of interspecific recombinants is essential to overcome the issues like self-pollination, environmental influence, and inadequacy of morphological characteristics during interspecific hybridization. The present study was conducted for genetic confirmation of mungbean (female) and mashbean (male) interspecific crosses using molecular markers. Initially, polymorphic random amplified polymorphic DNA (RAPD), universal rice primers (URP), and simple sequence repeats (SSR) markers differentiating parent genotypes were identified. Recombination in hybrids was confirmed using these polymorphic DNA markers. The NM 2006 × Mash 88 was most successful interspecific cross. Most of true recombinants confirmed by molecular markers were from this cross combination. SSR markers were efficient in detecting genetic variability and recombination with reference to specific chromosomes and particular loci. SSR (RIS) and RAPD identified variability dispersed throughout the genome. In conclusion, DNA based marker assisted selection (MAS) efficiently confirmed the interspecific recombinants. The results provided evidence that MAS can enhance the authenticity of selection in mungbean improvement program.

  15. Adults Who Do Not Want to Participate in Learning: A Cross-National European Analysis of Their Perceived Barriers

    Science.gov (United States)

    Roosmaa, Eve-Liis; Saar, Ellu

    2017-01-01

    This article explores cross-national differences in the intensity of perceived barriers to adult learning in Europe focusing on the barriers recognised by those not participating and having no intention to do so. This relatively large subgroup has received scant scholarly attention, yet exploring their participation barriers is critical for…

  16. Some results of applied interspecific hybridization in sunflower breeding

    International Nuclear Information System (INIS)

    Tsvetkova, F.

    1976-01-01

    Investigations on the interspecific hybridization in sunflower, aimed at developing a diversified initial selection material, were carried out Wild species of the diploid, tetraploid and hexaploid groups, varieties, hybrids, and selfed-lines of cultivated sunflower were used for crossings. To overcome incrossability between the species and sterility in the hybrids the method of f;cilitating of crossability by mutual gra'fting and gamma-rays treatment of seeds and pollen were applied. Results showed that: 1. By the method of interspecific hybridization forms might be produced resistant to more important diseases. 2. Interspecific hybridization in combination with other methods of selection might produce varieties and hybrids with a complex of valuable qualities. 3. Crossings between wild species and cultivated sunflower gave progenies with gene rale sterility. 4. The species H.tuberosus, H.scaberimus, H.arωphylus and H.lenticularis possess genes of full fertility restoration. (author)

  17. Genomic Characterization of Interspecific Hybrids and an Admixture Population Derived from Panicum amarum × P. virgatum

    Directory of Open Access Journals (Sweden)

    Christopher Heffelfinger

    2015-07-01

    Full Text Available Switchgrass ( L. and its relatives are regarded as top bioenergy crop candidates; however, one critical barrier is the introduction of useful genetic diversity and the development of new cultivars and hybrids. Combining genomes from related cultivars and species provides an opportunity to introduce new traits. In switchgrass, a breeding advantage would be achieved by combining the genomes of intervarietal ecotypes or interspecific hybrids. The recovery of wide crosses, however, is often tedious and may involve complicated embryo rescue and numerous backcrosses. Here, we demonstrate a straightforward approach to wide crosses involving the use of a selectable transgene for recovery of interspecific [ cv. Alamo × Ell var or Atlantic Coastal Panicgrass (ACP] F hybrids followed by backcrossing to generate a nontransgenic admixture population. A nontransgenic herbicide-sensitive (HbS admixture population of 83 FBC progeny was analyzed by genotyping-by-sequencing (GBS to characterize local ancestry, parental contribution, and patterns of recombination. These results demonstrate a widely applicable breeding strategy that makes use of transgenic selectable resistance to identify and recover true hybrids.

  18. Obtaining interspecific hybrids, and molecular analysis by microsatellite markers in grapevine

    OpenAIRE

    Mariane Ruzza Schuck; Luiz Antonio Biasi; Ada Michele Mariano; Bernardo Lipski; Summaira Riaz; Michael Andrew Walker

    2011-01-01

    The objective of this work was to assess the potential of interspecific hybridization of Vitis labruscana and Muscadinia rotundifolia by using artificial cross-pollinations. Microsatellite markers were used to confirm interspecific hybridizations and the identity of the parental genotypes. In crosses in which M. rotundifolia was used as the female parent, no true hybrids were obtained. In the reciprocal crosses, 114 seedlings were identified as true V. labruscana x M. rotundifolia hybrids. Se...

  19. Discursive barriers and cross-scale forest governance in Central Kalimantan, Indonesia

    Directory of Open Access Journals (Sweden)

    Caleb T. Gallemore

    2014-06-01

    Full Text Available Students of social-ecological systems have emphasized the need for effective cross-scale governance. We theorized that discursive barriers, particularly between technical and traditional practices, can act as a barrier to cross-scale collaboration. We analyzed the effects of discursive divides on collaboration on Reducing Emissions from Deforestation and Forest Degradation (REDD+ policy development in Central Kalimantan, an Indonesian province on the island of Borneo selected in 2010 to pilot subnational REDD+ policy. We argue that the complexities of bridging local land management practices and technical approaches to greenhouse gas emissions reduction and carbon offsetting create barriers to cross-scale collaboration. We tested these hypotheses using an exponential random graph model of collaboration among 36 organizations active in REDD+ policy in the province. We found that discursive divides were associated with a decreased probability of collaboration between organizations and that organizations headquartered outside the province were less likely to collaborate with organizations headquartered in the province. We conclude that bridging discursive communities presents a chicken-and-egg problem for cross-scale governance of social-ecological systems. In precisely the situations where it is most important, when bridging transnational standards with local knowledge and land management practices, it is the most difficult.

  20. Trojan Horse Transit Contributes to Blood-Brain Barrier Crossing of a Eukaryotic Pathogen.

    Science.gov (United States)

    Santiago-Tirado, Felipe H; Onken, Michael D; Cooper, John A; Klein, Robyn S; Doering, Tamara L

    2017-01-31

    The blood-brain barrier (BBB) protects the central nervous system (CNS) by restricting the passage of molecules and microorganisms. Despite this barrier, however, the fungal pathogen Cryptococcus neoformans invades the brain, causing a meningoencephalitis that is estimated to kill over 600,000 people annually. Cryptococcal infection begins in the lung, and experimental evidence suggests that host phagocytes play a role in subsequent dissemination, although this role remains ill defined. Additionally, the disparate experimental approaches that have been used to probe various potential routes of BBB transit make it impossible to assess their relative contributions, confounding any integrated understanding of cryptococcal brain entry. Here we used an in vitro model BBB to show that a "Trojan horse" mechanism contributes significantly to fungal barrier crossing and that host factors regulate this process independently of free fungal transit. We also, for the first time, directly imaged C. neoformans-containing phagocytes crossing the BBB, showing that they do so via transendothelial pores. Finally, we found that Trojan horse crossing enables CNS entry of fungal mutants that cannot otherwise traverse the BBB, and we demonstrate additional intercellular interactions that may contribute to brain entry. Our work elucidates the mechanism of cryptococcal brain invasion and offers approaches to study other neuropathogens. The fungal pathogen Cryptococcus neoformans invades the brain, causing a meningoencephalitis that kills hundreds of thousands of people each year. One route that has been proposed for this brain entry is a Trojan horse mechanism, whereby the fungus crosses the blood-brain barrier (BBB) as a passenger inside host phagocytes. Although indirect experimental evidence supports this intriguing mechanism, it has never been directly visualized. Here we directly image Trojan horse transit and show that it is regulated independently of free fungal entry, contributes

  1. Overcoming the species hybridization barrier by ploidy manipulation in the genus Oryza.

    Science.gov (United States)

    Tonosaki, Kaoru; Sekine, Daisuke; Ohnishi, Takayuki; Ono, Akemi; Furuumi, Hiroyasu; Kurata, Nori; Kinoshita, Tetsu

    2018-02-01

    In most eudicot and monocot species, interspecific and interploidy crosses generally display abnormalities in the endosperm that are the major cause of a post-zygotic hybridization barrier. In some eudicot species, however, this type of hybridization barrier can be overcome by the manipulation of ploidy levels of one parental species, suggesting that the molecular mechanisms underlying the species hybridization barrier can be circumvented by genome dosage. We previously demonstrated that endosperm barriers in interspecific and interploidy crosses in the genus Oryza involve overlapping but different mechanisms. This result contrasts with those in the genus Arabidopsis, which shows similar outcomes in both interploidy and interspecific crosses. Therefore, we postulated that an exploration of pathways for overcoming the species hybridization barrier in Oryza endosperm, by manipulating the ploidy levels in one parental species, might provide novel insights into molecular mechanisms. We showed that fertile hybrid seeds could be produced by an interspecific cross of female tetraploid Oryza sativa and male diploid Oryza longistaminata. Although the rate of nuclear divisions did not return to normal levels in the hybrid endosperm, the timing of cellularization, nucellus degeneration and the accumulation of storage products were close to normal levels. In addition, the expression patterns of the imprinted gene MADS87 and YUCCA11 were changed when the species barrier was overcome. These results suggest that the regulatory machinery for developmental transitions and imprinted gene expression are likely to play a central role in overcoming species hybridization barriers by genome dosage in the genus Oryza. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  2. Genetic analysis of post-mating reproductive barriers in hybridizing European Populus species

    OpenAIRE

    Macaya-Sanz, David; Suter, Leonie; Joseph, Jeffrey A.; Barbará, Thelma; Alba, N.; González-Martínez, S. C.; Widmer, Alex; Lexer, Christian

    2011-01-01

    Molecular genetic analyses of experimental crosses provide important information on the strength and nature of post-mating barriers to gene exchange between divergent populations, which are topics of great interest to evolutionary geneticists and breeders. Although not a trivial task in long-lived organisms such as trees, experimental interspecific recombinants can sometimes be created through controlled crosses involving natural F₁'s. Here, we used this approach to understand the genetics of...

  3. Universal trend for heavy-ion total reaction cross sections at energies above the Coulomb barrier

    International Nuclear Information System (INIS)

    Tavares, O.A.P.; Medeiros, E.L.; Morcelle, V.

    2010-06-01

    Heavy-ion total reaction cross section measurements for more than one thousand one hundred reaction cases covering 61 target nuclei in the range 6 Li- 238 U, and 158 projectile nuclei from 2 H up to 84 Kr (mostly exotic ones) have been analysed in a systematic way by using an empirical, three-parameter formula which is applicable to cases for projectile kinetic energies above the Coulomb barrier. The analysis has shown that the average total nuclear binding energy per nucleon of the interacting nuclei and their radii are the chief quantities which describe the cross section patterns. A great number of cross section data (87%) has been quite satisfactorily reproduced by the proposed formula, therefore total reaction cross section predictions for new, not yet experimentally investigated reaction cases can be obtained within 25 percent (or much less) of uncertainty (author)

  4. Universal trend for heavy-ion total reaction cross sections at energies above the Coulomb barrier

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, O.A.P.; Medeiros, E.L., E-mail: emil@cbpf.b [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Morcelle, V. [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica

    2010-06-15

    Heavy-ion total reaction cross section measurements for more than one thousand one hundred reaction cases covering 61 target nuclei in the range {sup 6}Li-{sup 238}U, and 158 projectile nuclei from {sup 2}H up to {sup 84}Kr (mostly exotic ones) have been analysed in a systematic way by using an empirical, three-parameter formula which is applicable to cases for projectile kinetic energies above the Coulomb barrier. The analysis has shown that the average total nuclear binding energy per nucleon of the interacting nuclei and their radii are the chief quantities which describe the cross section patterns. A great number of cross section data (87%) has been quite satisfactorily reproduced by the proposed formula, therefore total reaction cross section predictions for new, not yet experimentally investigated reaction cases can be obtained within 25 percent (or much less) of uncertainty (author)

  5. Comparison of different Skyrme forces: Fusion barriers and fusion cross sections

    International Nuclear Information System (INIS)

    Puri, R.K.; Gupta, R.K.

    1995-01-01

    Fusion barriers and fusion cross sections are calculated using the Skyrme energy-density formalism. To study the role of different parametrizations of the Skyrme interaction, we use two typical forces, i.e., the original Skyrme force S and the widely used Skyrme force SIII. Our calculations show that, in the reactions considered here, the Skyrme force S gives higher fusion cross sections compared to that of the Skyrme force SIII. The main part of this difference can be associated with the presence of the spin-density contribution in the Skyrme force SIII

  6. Cross-sections and average angular momenta in fusion reactions near the coulomb barrier

    International Nuclear Information System (INIS)

    Dasgupta, M.

    1992-01-01

    In recent years there has been an increasing interest in the study of heavy ion collisions near the Coulomb barrier. This has been triggered mainly by the observations of enhancements by factors of about one to two order of magnitude in sub-Coulomb barrier fusion (SBF) cross-sections between medium mass nuclei, as compared to predictions based on one-dimensional barrier penetration model (l-d BPM). Though, a considerable amount of work both theoretical and experimental has been done in this field, a complete understanding of the SBF phenomenon has not yet been achieved. The relation between fusion excitation function and angular momentum (l) distribution in SBF reactions is a topic of current interest. It is believed that l-distributions provide a more stringent test of SBF models that the excitation functions alone. Simultaneous measurement of l-distribution (or its moments) and fusion excitation function is expected to lead to a better understanding of the relationship between these two qualities. Such information has been obtained in experiments done at pelletron accelerator facility. In the present talk the measurement of fusion cross-sections and the method of determination of average l from partial evaporation residue cross-section has been elaborated. An analysis of the experimental data on the basis of some of the SBF models has been discussed briefly. (author). 13 refs

  7. Activated barrier crossing dynamics in the non-radiative decay of NADH and NADPH

    Energy Technology Data Exchange (ETDEWEB)

    Blacker, Thomas S., E-mail: t.blacker@ucl.ac.uk [Centre for Mathematics and Physics in the Life Sciences and Experimental Biology (CoMPLEX), University College London, London WC1E 6BT (United Kingdom); Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom); Research Department of Cell and Developmental Biology, University College London, London WC1E 6BT (United Kingdom); Marsh, Richard J., E-mail: richard.marsh@ucl.ac.uk [Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom); Duchen, Michael R., E-mail: m.duchen@ucl.ac.uk [Research Department of Cell and Developmental Biology, University College London, London WC1E 6BT (United Kingdom); Bain, Angus J., E-mail: a.bain@ucl.ac.uk [Centre for Mathematics and Physics in the Life Sciences and Experimental Biology (CoMPLEX), University College London, London WC1E 6BT (United Kingdom); Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom)

    2013-08-30

    Highlights: ► NADH and NADPH have a high rate of non-radiative excited state decay. ► Conformational relaxation is shown to be a significant non-radiative pathway. ► The Kramers equation describes the barrier crossing dynamics of the relaxation. ► Conformational restriction upon enzyme binding will alter NAD(P)H lifetimes. - Abstract: In live tissue, alterations in metabolism induce changes in the fluorescence decay of the biological coenzyme NAD(P)H, the mechanism of which is not well understood. In this work, the fluorescence and anisotropy decay dynamics of NADH and NADPH were investigated as a function of viscosity in a range of water–glycerol solutions. The viscosity dependence of the non-radiative decay is well described by Kramers and Kramers–Hubbard models of activated barrier crossing over a wide viscosity range. Our combined lifetime and anisotropy analysis indicates common mechanisms of non-radiative relaxation in the two emitting states (conformations) of both molecules. The low frequencies associated with barrier crossing suggest that non-radiative decay is mediated by small scale motion (e.g. puckering) of the nicotinamide ring. Variations in the fluorescence lifetimes of NADH and NADPH when bound to different enzymes may therefore be attributed to differing levels of conformational restriction upon binding.

  8. The effects of different pollination methods on overcoming distant cross barriers of the Lily 'cordelia' x Lilium dauricum

    International Nuclear Information System (INIS)

    Ma Li; Zhang Qixiang; Zhang Kezhong; Jia Yuehui; Wang Zhe

    2008-01-01

    The application of irradiated pollen assisting pollination, cross chemical assisting pollination and cut-style pollination in overcoming the cross barriers of lily 'cordelia' x Lilium dauricum were investigated. A number of fruits and plump seeds were produced by using the normal stigma pollination, which indicated that the cross was a compatible cross. The fact that the application of 1000 Gy or 2000 Gy irradiated pollen assisting pollination increased the fruitset and seedset obviously exhibited that this methods could overcome the cross barriers effectively. More hybrid seeds would have a positive effect on the future breeding selection. Application of cross chemical's assisting pollination raised the fruitset and seedset to some extent. The cut-style pollination method deduced the fruitset and seedset, which suggested that the method was not suitable for bypassing the cross barriers. (authors)

  9. Drosophila interspecific hybrids phenocopy piRNA-pathway mutants.

    Directory of Open Access Journals (Sweden)

    Erin S Kelleher

    Full Text Available The Piwi-interacting RNA (piRNA pathway defends the germline of animals from the deleterious activity of selfish transposable elements (TEs through small-RNA mediated silencing. Adaptation to novel invasive TEs is proposed to occur by incorporating their sequences into the piRNA pool that females produce and deposit into their eggs, which then propagates immunity against specific TEs to future generations. In support of this model, the F1 offspring of crosses between strains of the same Drosophila species sometimes suffer from germline derepression of paternally inherited TE families, caused by a failure of the maternal strain to produce the piRNAs necessary for their regulation. However, many protein components of the Drosophila piRNA pathway exhibit signatures of positive selection, suggesting that they also contribute to the evolution of host genome defense. Here we investigate piRNA pathway function and TE regulation in the F1 hybrids of interspecific crosses between D. melanogaster and D. simulans and compare them with intraspecific control crosses of D. melanogaster. We confirm previous reports showing that intraspecific crosses are characterized by derepression of paternally inherited TE families that are rare or absent from the maternal genome and piRNA pool, consistent with the role of maternally deposited piRNAs in shaping TE silencing. In contrast to the intraspecific cross, we discover that interspecific hybrids are characterized by widespread derepression of both maternally and paternally inherited TE families. Furthermore, the pattern of derepression of TE families in interspecific hybrids cannot be attributed to their paucity or absence from the piRNA pool of the maternal species. Rather, we demonstrate that interspecific hybrids closely resemble piRNA effector-protein mutants in both TE misregulation and aberrant piRNA production. We suggest that TE derepression in interspecific hybrids largely reflects adaptive divergence of pi

  10. Production of interspecific Campanula hybrids by ovule culture

    DEFF Research Database (Denmark)

    Röper, A. C.; Lütken, H.; Christensen, B.

    2015-01-01

    The Campanula genus comprises several economically important ornamental plants species. Wide hybridisation is a method to increase phenotypic variability, but is limited due to interspecies hybridisation barriers. In this study we investigated whether ovule culture could be used to increase....... With this study, a protocol for ovule culture was established and the usefulness of ovule culture to obtain interspecific hybrids of selected Campanula species was demonstrated....

  11. Mapping of quantitative trait locus (QTLs that contribute to germination and early seedling drought tolerance in the interspecific cross Setaria italica×Setaria viridis.

    Directory of Open Access Journals (Sweden)

    Lufeng Qie

    Full Text Available Drought tolerance is an important breeding target for enhancing the yields of grain crop species in arid and semi-arid regions of the world. Two species of Setaria, domesticated foxtail millet (S. italica and its wild ancestor green foxtail (S. viridis are becoming widely adopted as models for functional genomics studies in the Panicoid grasses. In this study, the genomic regions controlling germination and early seedling drought tolerance in Setaria were identified using 190 F7 lines derived from a cross between Yugu1, a S. italica cultivar developed in China, and a wild S. viridis genotype collected from Uzbekistan. Quantitative trait loci were identified which contribute to a number of traits including promptness index, radical root length, coleoptile length and lateral root number at germinating stage and seedling survival rate was characterized by the ability of desiccated seedlings to revive after rehydration. A genetic map with 128 SSR markers which spans 1293.9 cM with an average of 14 markers per linkage group of the 9 linkage groups was constructed. A total of eighteen QTLs were detected which included nine that explained over 10% of the phenotypic variance for a given trait. Both the wild green foxtail genotype and the foxtail millet cultivar contributed the favorite alleles for traits detected in this trial, indicating that wild Setaria viridis populations may serve as a reservoir for novel stress tolerance alleles which could be employed in foxtail millet breeding.

  12. Mapping of quantitative trait locus (QTLs) that contribute to germination and early seedling drought tolerance in the interspecific cross Setaria italica×Setaria viridis.

    Science.gov (United States)

    Qie, Lufeng; Jia, Guanqing; Zhang, Wenying; Schnable, James; Shang, Zhonglin; Li, Wei; Liu, Binhui; Li, Mingzhe; Chai, Yang; Zhi, Hui; Diao, Xianmin

    2014-01-01

    Drought tolerance is an important breeding target for enhancing the yields of grain crop species in arid and semi-arid regions of the world. Two species of Setaria, domesticated foxtail millet (S. italica) and its wild ancestor green foxtail (S. viridis) are becoming widely adopted as models for functional genomics studies in the Panicoid grasses. In this study, the genomic regions controlling germination and early seedling drought tolerance in Setaria were identified using 190 F7 lines derived from a cross between Yugu1, a S. italica cultivar developed in China, and a wild S. viridis genotype collected from Uzbekistan. Quantitative trait loci were identified which contribute to a number of traits including promptness index, radical root length, coleoptile length and lateral root number at germinating stage and seedling survival rate was characterized by the ability of desiccated seedlings to revive after rehydration. A genetic map with 128 SSR markers which spans 1293.9 cM with an average of 14 markers per linkage group of the 9 linkage groups was constructed. A total of eighteen QTLs were detected which included nine that explained over 10% of the phenotypic variance for a given trait. Both the wild green foxtail genotype and the foxtail millet cultivar contributed the favorite alleles for traits detected in this trial, indicating that wild Setaria viridis populations may serve as a reservoir for novel stress tolerance alleles which could be employed in foxtail millet breeding.

  13. A stakeless yard long bean cultivar derived from an interspecific cross between cowpea Vigna unguiculata L. (Walp) and yard long bean Vigna sesquipedalis L. (Verdc.)

    International Nuclear Information System (INIS)

    Luadthong, Sanit

    1990-01-01

    Full text: 'Yard long bean' is an important vegetable in the Thai diet, particularly in Northeast Thailand. However, growing 'yard long beans' requires stakes for supporting the twining stems and keeping the pod from touching the ground. Staking costs money, takes time and needs labour. An ideal cultivar would be a 'yard long bean' with erect plant type and under 80 cm in height that produces typical long bean pods and allows convenient picking during the harvest time. An attempt to breed such a cultivar was made by crossing cowpea Vigna unguiculata L. (Walp.) with' yard long bean' Vigna sesquipedalis L. (Verdc.) in 1984. This resulted in a new cultivar 'KKU 25'. This cultivar, having erect plant type, requires no staking for supporting the stem and produces long fresh pods with acceptable taste which can be harvested within 43 days. The average pod length is 48 cm, and pod diameter 1.43 cm. In a preliminary yield trial, an average fresh pod yield of 16 t/ha was obtained. (author)

  14. A cross-cultural survey of residents' perceived barriers in questioning/challenging authority.

    Science.gov (United States)

    Kobayashi, H; Pian-Smith, M; Sato, M; Sawa, R; Takeshita, T; Raemer, D

    2006-08-01

    To identify perceived barriers to residents' questioning or challenging their seniors, to determine how these barriers affect decisions, and to assess how these barriers differ across cultures. A written questionnaire was administered to residents in teaching hospitals in the US and Japan to assess factors affecting residents' willingness to question or challenge their superiors. The responses were analyzed for statistical significance of differences between the two cultures and to determine the importance of issues affecting decisions. Questionnaires were completed by 175 US and 65 Japanese residents, with an overall response rate of 71%. Trainees from both countries believe that questioning and challenging contribute to safety. The perceived importance of specific beliefs about the workplace differed across cultures in seven out of 22 questions. Residents' decisions to make a challenge were related to the relationships and perceived response of the superiors. There was no statistical difference between the US and Japanese residents in terms of the threshold for challenging their seniors. We have identified attributes of residents' beliefs of communication, including several cross-cultural differences in the importance of values and issues affecting one's decision to question or challenge. In contrast, there was no difference in the threshold for challenging seniors by the Japanese and US residents studied. Changes in organizational and professional culture may be as important, if not more so, than national culture to encourage "speaking up". Residents should be encouraged to overcome barriers to challenging, and training programs should foster improved relationships and communication between trainers and trainees.

  15. Postpartum nurses' perceptions of barriers to screening for intimate partner violence: a cross-sectional survey

    Directory of Open Access Journals (Sweden)

    Guillery Margaret E

    2012-02-01

    Full Text Available Abstract Background Intimate partner violence (IPV is a human rights violation that is pervasive worldwide, and is particularly critical for women during the reproductive period. IPV includes physical, sexual and emotional abuse. Nurses on in-patient postpartum units are well-positioned to screen women for IPV, yet low screening rates suggest that barriers to screening exist. The purpose of this study was to (a identify the frequency of screening for IPV, (b the most important barriers to screening, (c the relationship between the barriers to screening and the frequency of screening for types of abuse, and (d to identify other factors that contribute to the frequency of screening for IPV. Methods In 2008, we conducted a cross-sectional survey of 96 nurses from postpartum inpatient units in three Canadian urban hospitals. The survey included the Barriers to Abuse Assessment Tool (BAAT, adapted for postpartum nurses (PPN. Ordinary least squares (OLS regression models were used to predict barriers to screening for each type of IPV. Results The frequency of screening varied by the type of abuse with highest screening rates found for physical and emotional abuse. According to the BAAT-PPN, lack of knowledge was the most important barrier to screening. The BAAT-PPN total score was negatively correlated with screening for physical, sexual, and emotional abuse. Using OLS regression models and after controlling for demographic characteristics, the BAAT-PPN explained 14%, 12%, and 11% of the variance in screening for physical, sexual and emotional abuse, respectively. Fluency in the language of the patient was negatively correlated with screening for each type of abuse. When added as Step 3 to OLS regression models, language fluency was associated with an additional decrease in the likelihood of screening for physical (beta coefficient = -.38, P P = .05, and emotional abuse (beta coefficient = -.48, P Conclusions Our findings support an inverse

  16. Backcrosses in interspecific hybridization in sunflower

    Directory of Open Access Journals (Sweden)

    Atlagić Jovanka

    2003-01-01

    Full Text Available When incorporating desirable traits (resistance to causal agents of various diseases from the wild relatives into the cultivated sunflower, some undesirable ones are introduced too (branching, small head diameter, low oil content, etc. To overcome this problem, backcrosses (F1 interspecific hybrids x cultivated sunflower are used, although very often desirable traits are lost in the process. Cytological analysis (meiosis and pollen viability and molecular markers (RAPD were used to estimate what portion of the parental species genome was present in (be interspecific hybrids of the F1 and BC1F1 generations. The results showed that the percentage of irregularities at meiosis increased from F1 to BC1F1 gen. They also indicated the presence of aneuploids and sterility in the cross between the hexaploid species H.rigidus and cultivated sunflower. The genetic distance between the parents was 83%, that between H.rigidus and the F1 hybrid 54 61%, and that between H.annuus and F1 hybrid 70-76%. In the BC1F1 generation, the genetic distance from Hannuus decreased to 58-66% and that from H.rigidus increased to 69-76%.

  17. GENETIC DIVERSITY OF INTERSPECIFIC HYBRIDS OF THE GENUS ALLIUM L.

    Directory of Open Access Journals (Sweden)

    V. S. Romanov

    2018-01-01

    Full Text Available Selection based on interspecific hybridization of fundamentally new plant forms with a unique combination of genetic material allows expanding the scope of genotypic and phenotypic variability. In this work the comparative analysis of plants of interspecific hybrids of genus Allium L. from various inbred descendants of combinations of crossing of species A. cepa х A. vavilovii and A. cepa х A. fistulosum on selection traits is carried out.Forms were identified: by mass of the bulb more than 100 g; with contrasting coloration of dry cover scales bulbs; by the index of the shape of the bulb; on the resistance to peronosporosis of plants of the first year of vegetation and seed plants; by the number of arrows; height of the arrow; on seed production with a sufficiently high percentage of fertile plants. Plants of interspecific hybrids of onions formed bulbs weighing from 20 to 120 g, with white, golden-yellow, dark golden-yellow, brownish and dark purple color of dry covering scales of a bulb. Plants of interspecific hybrids of onions were flat and round-flat shape of the bulb with the frequency of symptoms ranging from 6.9 to 93.3% and from 11.7 to 93.3%. In a phytopathological evaluation of interspecific hybrids of onions the first year of vegetation identified plants with resistance to downy mildew is from 0 to 4.0 points. Was studied the frequency of occurrence of plants in the progenies weight, colour, bulb type, number, height of the seedstalk, seed productivity and resistance to downy mildew. The increase of genetic diversity in onion plants obtained on the basis of interspecific hybridization, backcrossing and inbreeding is shown.

  18. Controle genético da concentração de 2-Tridecanona e de 2-Undecanona em cruzamentos interespecíficos de tomateiro Genetic control of 2-Tridecanone and 2-Undecanone concentration in tomato interspecific cross

    Directory of Open Access Journals (Sweden)

    NORMA ELIANE PEREIRA

    2000-01-01

    Full Text Available Estudou-se o controle genético da concentração das metil-cetonas 2-tridecanona (2-TD e 2-undecanona (2-UN no cruzamento de Lycopersicon esculentum cv IPA-6 x L. hirsutum f. glabratum PI 134418. Para tal, as gerações parentais F1 e F2 foram avaliadas em experimento de casa de vegetação, sendo a quantificação das metil-cetonas foliares realizada por cromatografia gasosa com coluna capilar. Os resultados revelaram alta correlação (0,97; P > 0,001 entre as concentrações de 2-TD e 2-UN, possivelmente devido à ocorrência de efeitos pleiotrópicos ou de ligação gênica. O grau médio de dominância revelou a ocorrência de dominância parcial para as menores concentrações de 2-TD e 2-UN, cujas herdabilidades foram 0,75 e 0,78 respectivamente. A análise de média de gerações mostrou não haver adequação dos dados de concentração de 2-TD e 2-UN ao modelo aditivo-dominante, devido, possivelmente, a problemas de incongruidade ou a efeitos epistáticos.Genetic control of methyl-ketones 2-tridecanone (2-TD and 2-undecanone (2-UN concentration was studied in a cross of Lycopersicon esculentum cv IPA-6 x L. hirsutum f. glabratum PI 134418. The progenitors F1 and F2 generations were evalueted in a green house experiment, and the level of methyl-ketones in the leaves were determined by capilar gas chromatography. The results indicate that there is high correlations between 2-TD and 2-UN concentrations (0.97; P > 0.001, indicating that pleiotropic or genic linkage effects may be occurring. The 2-TD and 2-UN showed complete dominance for low concentration and high heritability, 0.75 and 0.78, respectively. The generation means analysis showed that the results of 2-TD and 2-UN concentration can not be explained by the simple additive-dominant model, suggesting that the segregation distortion could be due to incongruity problems of interspecific crosses or epistatic gene action.

  19. 12C+16O sub-barrier radiative capture cross-section measurements

    International Nuclear Information System (INIS)

    Goasduff, A.; Courtin, S.; Haas, F.; Beck, C.; Lebhertz, D.; Jenkins, D.G.; Fallis, J.; Ruiz, C.; Hutcheon, D.A.; Amandruz, P.A.; Davis, C.; Hager, U.; Ottewell, D.; Ruprecht, G.

    2011-01-01

    We have performed a heavy ion radiative capture reaction between two light heavy ions, 12 C and 16 O, leading to 28 Si. The present experiment has been performed below Coulomb barrier energies in order to reduce the phase space and to try to shed light on structural effects. Obtained γ-spectra display a previously unobserved strong feeding of intermediate states around 11 MeV at these energies. This new decay branch is not fully reproduced by statistical nor semi-statistical decay scenarios and may imply structural effects. Radiative capture cross-sections are extracted from the data. (authors)

  20. Total reaction cross section for 12C+16O below the Coulomb barrier

    International Nuclear Information System (INIS)

    Cujec, B.; Barnes, C.A.

    1976-01-01

    The energy dependence of the total reaction cross section, sigma(E), for 12 C+ 16 0 has been measured over the range Esub(c.m.)=4-12 MeV, by detecting γ-rays from the various possible residual nuclei with two large NaI(Tl) detectors placed close to the target. This technique for measuring total reaction cross sections was explored in some detail and shown to yield reliable values for sigma(E). Although the principal emphasis of this work was placed on obtaining reliable cross sections, a preliminary study has been made of the suitability of various methods for extrapolating the cross section to still lower energies. The statistical model provides a good fit with a reasonable value for the strength function, 2 >/ =6.8x10 -2 , over the range Esub(c.m.)=6.5-12 MeV, but predicts cross sections which are much too large for Esub(c.m.)<6.5 MeV. Optical model fits at low energies are especially sensitive to the radius and diffuseness of the imaginary component of the potential and, since these are still poorly known at present, such extrapolations may be wrong by orders of magnitude. A simple barrier penetration model gives a moderately good fit to the data and seems to provide the safest extrapolation to lower energies at the present time. It is clear, however, that our knowledge of the heavy-ion reaction mechanism at low energies is incomplete, and that cross-section measurements at still lower energies are needed to establish the correct procedure for extrapolating heavy-ion reaction cross sections to low energies. (Auth.)

  1. Iranian Nurses’ Views on Barriers and Facilitators in Patient Education: A Cross-Sectional Study

    Science.gov (United States)

    Ramezanli, Somayeh; Jahromi, Zohreh Badiyepeymaie

    2015-01-01

    Background: As a major factor in patient-centered care, patient education has a great impact on the quality of care provided by nurses; however, clinical nurses’ performance with regard to patient education is not satisfactory. This study is an attempt to investigate barriers and facilitators in patient education from nurses’ point of view. Methods: 122 nurses at Jahrom University of Medical Sciences participated in this descriptive-cross sectional study. Sampling was based on the census method. The questionnaire used to collect data included questions about nurses’ demography, barriers (10 questions), and facilitators (10 questions) in patient education. The questionnaire was designed to be completed independently. To analyze the data, the researchers used descriptive statistics, including frequency, mean and standard deviation. Results: The highest scores related to barriers to patient education were: nurses’ insufficient knowledge, patients’ physical and emotional unpreparedness, and lack of a proper environment for education. The most important facilitators, on the other hand, were: enhancement of instructing nurses’ knowledge and skills, motivating nurses, and a step-by-step approach to patient education. Conclusion: It is important that nurses be prepared and motivated to train their patients. By satisfactory patient education on the part of nurses, patients will be more willing to cooperate in the treatment process. PMID:26156926

  2. Iranian Nurses' Views on Barriers and Facilitators in Patient Education: A Cross-Sectional Study.

    Science.gov (United States)

    Ramezanli, Somayeh; Badiyepeymaie Jahromi, Zohreh

    2015-03-18

    As a major factor in patient-centered care, patient education has a great impact on the quality of care provided by nurses; however, clinical nurses' performance with regard to patient education is not satisfactory. This study is an attempt to investigate barriers and facilitators in patient education from nurses' point of view. 122 nurses at Jahrom University of Medical Sciences participated in this descriptive-cross sectional study. Sampling was based on the census method. The questionnaire used to collect data included questions about nurses' demography, barriers (10 questions), and facilitators (10 questions) in patient education. The questionnaire was designed to be completed independently. To analyze the data, the researchers used descriptive statistics, including frequency, mean and standard deviation. The highest scores related to barriers to patient education were: nurses' insufficient knowledge, patients' physical and emotional unpreparedness, and lack of a proper environment for education. The most important facilitators, on the other hand, were: enhancement of instructing nurses' knowledge and skills, motivating nurses, and a step-by-step approach to patient education. It is important that nurses be prepared and motivated to train their patients. By satisfactory patient education on the part of nurses, patients will be more willing to cooperate in the treatment process.

  3. Evolutionary disarmament in interspecific competition.

    Science.gov (United States)

    Kisdi, E; Geritz, S A

    2001-12-22

    Competitive asymmetry, which is the advantage of having a larger body or stronger weaponry than a contestant, drives spectacular evolutionary arms races in intraspecific competition. Similar asymmetries are well documented in interspecific competition, yet they seldom lead to exaggerated traits. Here we demonstrate that two species with substantially different size may undergo parallel coevolution towards a smaller size under the same ecological conditions where a single species would exhibit an evolutionary arms race. We show that disarmament occurs for a wide range of parameters in an ecologically explicit model of competition for a single shared resource; disarmament also occurs in a simple Lotka-Volterra competition model. A key property of both models is the interplay between evolutionary dynamics and population density. The mechanism does not rely on very specific features of the model. Thus, evolutionary disarmament may be widespread and may help to explain the lack of interspecific arms races.

  4. Facilitators and barriers experienced by federal cross-sector partners during the implementation of a healthy eating campaign.

    Science.gov (United States)

    Fernandez, Melissa Anne; Desroches, Sophie; Marquis, Marie; Turcotte, Mylène; Provencher, Véronique

    2017-09-01

    To identify facilitators and barriers that Health Canada's (HC) cross-sector partners experienced while implementing the Eat Well Campaign: Food Skills (EWC; 2013-2014) and describe how these experiences might differ according to distinct partner types. A qualitative study using hour-long semi-structured telephone interviews conducted with HC partners that were transcribed verbatim. Facilitators and barriers were identified inductively and analysed according partner types. Implementation of a national mass-media health education campaign. Twenty-one of HC's cross-sector partners (food retailers, media and health organizations) engaged in the EWC. Facilitators and barriers were grouped into seven major themes: operational elements, intervention factors, resources, collaborator traits, developer traits, partnership factors and target population factors. Four of these themes had dual roles as both facilitators and barriers (intervention factors, resources, collaborator traits and developer traits). Sub-themes identified as both facilitators and barriers illustrate the extent to which a facilitator can easily become a barrier. Partnership factors were unique facilitators, while operational and target population factors were unique barriers. Time was a barrier that was common to almost all partners regardless of partnership type. There appeared to be a greater degree of uniformity among facilitators, whereas barriers were more diverse and unique to the realities of specific types of partner. Collaborative planning will help public health organizations anticipate barriers unique to the realities of specific types of organizations. It will also prevent facilitators from becoming barriers. Advanced planning will help organizations manage time constraints and integrate activities, facilitating implementation.

  5. Fusion cross sections for 6,7Li + 24Mg reactions at energies below and above the barrier

    International Nuclear Information System (INIS)

    Ray, M.; Mukherjee, A.; Pradhan, M. K.; Kshetri, Ritesh; Sarkar, M. Saha; Dasmahapatra, B.; Palit, R.; Majumdar, I.; Joshi, P. K.; Jain, H. C.

    2008-01-01

    Measurement of fusion cross sections for the 6,7 Li + 24 Mg reactions by the characteristic γ-ray method has been done at energies from below to well above the respective Coulomb barriers. The fusion cross sections obtained from these γ-ray cross sections for the two systems are found to agree well with the total reaction cross sections at low energies. The relatively large difference between total cross sections and measured fusion cross sections at higher energies is consistent with the fact that other channels, in particular breakup, open up with an increase of bombarding energy. The breakup channel, however, appears not to have any influence on fusion cross sections. The critical angular momenta (l cr ) deduced from the fusion cross sections are found to have an energy dependence similar to other Li-induced reactions

  6. Fission barrier theory and its application to the calculation of actinide neutron cross-sections

    International Nuclear Information System (INIS)

    Lynn, J.E.

    1980-01-01

    The lectures discuss the possibilities and realisations of applying nuclear fission theory to the calculation of unknown nuclear data required for applications, principally in the nuclear power field. A brief description of the fundamentals of fission theory, the nature of the potential energy surface in the deformation plane, and of the inertial tensor, is given, and the accuracy of the theoretical calculations is discussed. It is concluded that it is impracticable to obtain required quantities such as neutron cross-sections from such fundamental calculations at present. On the other hand the fundamental theory reveals a wealth of phenomenological aspects of the fission process which can be incorporated into nuclear reaction theory. It is then shown how reaction theory thus extended to take correct account of the structured (''double-humped'') fission barrier can be used to parametrise the barrier by analysis of experimental data, and subsequently to calculate new data. Descriptions of computer programmes and illustrations of the application of the methods to actual physical examples are included in this account. (author)

  7. Maternal exposure to carbamazepine at environmental concentrations can cross intestinal and placental barriers

    Energy Technology Data Exchange (ETDEWEB)

    Kaushik, Gaurav, E-mail: kausgaur@isu.edu [Department of Biological Sciences, Idaho State University, Stop 8007, 921 S 8th Ave, Pocatello, ID 83209-8007 (United States); Department of Medical Pathology and Laboratory Medicine, University of California at Davis, Davis, CA 95817 (United States); Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children, Northern California, 2425 Stockton Boulevard, Sacramento, CA 95817 (United States); Huber, David P., E-mail: hubedavi@isu.edu [Department of Biological Sciences, Idaho State University, Stop 8007, 921 S 8th Ave, Pocatello, ID 83209-8007 (United States); Aho, Ken, E-mail: ahoken@isu.edu [Department of Biological Sciences, Idaho State University, Stop 8007, 921 S 8th Ave, Pocatello, ID 83209-8007 (United States); Finney, Bruce, E-mail: finney@isu.edu [Department of Biological Sciences, Idaho State University, Stop 8007, 921 S 8th Ave, Pocatello, ID 83209-8007 (United States); Bearden, Shawn, E-mail: bearshaw@isu.edu [Department of Biological Sciences, Idaho State University, Stop 8007, 921 S 8th Ave, Pocatello, ID 83209-8007 (United States); Zarbalis, Konstantinos S., E-mail: kzarbalis@ucdavis.edu [Department of Medical Pathology and Laboratory Medicine, University of California at Davis, Davis, CA 95817 (United States); Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children, Northern California, 2425 Stockton Boulevard, Sacramento, CA 95817 (United States); Thomas, Michael A., E-mail: mthomas@isu.edu [Department of Biological Sciences, Idaho State University, Stop 8007, 921 S 8th Ave, Pocatello, ID 83209-8007 (United States)

    2016-05-27

    Psychoactive pharmaceuticals have been found as teratogens at clinical dosage during pregnancy. These pharmaceuticals have also been detected in minute (ppb) concentrations in drinking water in the US, and are environmental contaminants that may be complicit in triggering neurological disorders in genetically susceptible individuals. Previous studies have determined that psychoactive pharmaceuticals (fluoxetine, venlafaxine and carbamazepine) at environmentally relevant concentrations enriched sets of genes regulating development and function of the nervous system in fathead minnows. Altered gene sets were also associated with potential neurological disorders, including autism spectrum disorders (ASD). Subsequent in vitro studies indicated that psychoactive pharmaceuticals altered ASD-associated synaptic protein expression and gene expression in human neuronal cells. However, it is unknown if environmentally relevant concentrations of these pharmaceuticals are able to cross biological barriers from mother to fetus, thus potentially posing risks to nervous system development. The main objective of this study was to test whether psychoactive pharmaceuticals (fluoxetine, venlafaxine, and carbamazepine) administered through the drinking water at environmental concentrations to pregnant mice could reach the brain of the developing embryo by crossing intestinal and placental barriers. We addressed this question by adding {sup 2}H-isotope labeled pharmaceuticals to the drinking water of female mice for 20 days (10 pre-and 10 post–conception days), and quantifying {sup 2}H-isotope enrichment signals in the dam liver and brain of developing embryos using isotope ratio mass spectrometry. Significant levels of {sup 2}H enrichment was detected in the brain of embryos and livers of carbamazepine-treated mice but not in those of control dams, or for fluoxetine or venlafaxine application. These results provide the first evidence that carbamazepine in drinking water and at

  8. Maternal exposure to carbamazepine at environmental concentrations can cross intestinal and placental barriers

    International Nuclear Information System (INIS)

    Kaushik, Gaurav; Huber, David P.; Aho, Ken; Finney, Bruce; Bearden, Shawn; Zarbalis, Konstantinos S.; Thomas, Michael A.

    2016-01-01

    Psychoactive pharmaceuticals have been found as teratogens at clinical dosage during pregnancy. These pharmaceuticals have also been detected in minute (ppb) concentrations in drinking water in the US, and are environmental contaminants that may be complicit in triggering neurological disorders in genetically susceptible individuals. Previous studies have determined that psychoactive pharmaceuticals (fluoxetine, venlafaxine and carbamazepine) at environmentally relevant concentrations enriched sets of genes regulating development and function of the nervous system in fathead minnows. Altered gene sets were also associated with potential neurological disorders, including autism spectrum disorders (ASD). Subsequent in vitro studies indicated that psychoactive pharmaceuticals altered ASD-associated synaptic protein expression and gene expression in human neuronal cells. However, it is unknown if environmentally relevant concentrations of these pharmaceuticals are able to cross biological barriers from mother to fetus, thus potentially posing risks to nervous system development. The main objective of this study was to test whether psychoactive pharmaceuticals (fluoxetine, venlafaxine, and carbamazepine) administered through the drinking water at environmental concentrations to pregnant mice could reach the brain of the developing embryo by crossing intestinal and placental barriers. We addressed this question by adding "2H-isotope labeled pharmaceuticals to the drinking water of female mice for 20 days (10 pre-and 10 post–conception days), and quantifying "2H-isotope enrichment signals in the dam liver and brain of developing embryos using isotope ratio mass spectrometry. Significant levels of "2H enrichment was detected in the brain of embryos and livers of carbamazepine-treated mice but not in those of control dams, or for fluoxetine or venlafaxine application. These results provide the first evidence that carbamazepine in drinking water and at typical

  9. Crossing the Blood-Brain Barrier: Recent Advances in Drug Delivery to the Brain.

    Science.gov (United States)

    Patel, Mayur M; Patel, Bhoomika M

    2017-02-01

    CNS disorders are on the rise despite advancements in our understanding of their pathophysiological mechanisms. A major hurdle to the treatment of these disorders is the blood-brain barrier (BBB), which serves as an arduous janitor to protect the brain. Many drugs are being discovered for CNS disorders, which, however fail to enter the market because of their inability to cross the BBB. This is a pronounced challenge for the pharmaceutical fraternity. Hence, in addition to the discovery of novel entities and drug candidates, scientists are also developing new formulations of existing drugs for brain targeting. Several approaches have been investigated to allow therapeutics to cross the BBB. As the molecular structure of the BBB is better elucidated, several key approaches for brain targeting include physiological transport mechanisms such as adsorptive-mediated transcytosis, inhibition of active efflux pumps, receptor-mediated transport, cell-mediated endocytosis, and the use of peptide vectors. Drug-delivery approaches comprise delivery from microspheres, biodegradable wafers, and colloidal drug-carrier systems (e.g., liposomes, nanoparticles, nanogels, dendrimers, micelles, nanoemulsions, polymersomes, exosomes, and quantum dots). The current review discusses the latest advancements in these approaches, with a major focus on articles published in 2015 and 2016. In addition, we also cover the alternative delivery routes, such as intranasal and convection-enhanced diffusion methods, and disruption of the BBB for brain targeting.

  10. Interspecific hybridization between Crassostrea angulata and C. ariakensis

    Science.gov (United States)

    Yao, Tuo; Zhang, Yuehuan; Yan, Xiwu; Wang, Zhaoping; Li, Dongchun; Su, Jiaqi; Yu, Ruihai

    2015-08-01

    Interspecific hybridization can generate heterosis, which is proven to be a useful tool in selective breeding programs for oyster culture. Crassostrea angulata and C. ariakensis are two important economic shellfish species in China. We conducted 2 × 2 reciprocal crosses to determine whether these two species can cross-fertilize and their hybrids can hatch, survive and perform heterosis. Fertilization was found symmetrical without delay. The rate of fertilization success of C. angulata ♀ × C. ariakensis ♂ was lower than that of C. ariakensis ♀ × C. angulata ♂, and the success rate of both hybridizations was lower than that of two intraspecific crosses each. During the planktonic period, survival rate of the progeny was lower in the hybrid crosses than in the intraspecific crosses. On day 360, mean shell height of the progeny of C. angulata ♀ × C. angulata ♂ was highest, which was followed by that of C. angulata ♀ × C. ariakensis ♂, C. ariakensis ♀ × C. ariakensis ♂ and C. ariakensis ♀ × C. angulata ♂ in a descending order. Morphology of adults produced by the hybrid crosses was similar to that of C. angulata. Both hybrids underwent normal gonad development and produced mature gametes in the mating season. This study provided new insights into the quantitative traits in interspecific crosses of Crassostrea species, thus being of guidance value for selective breeding of oyster.

  11. Targeting and crossing of the human maternofetal barrier by Listeria monocytogenes: role of internalin interaction with trophoblast E-cadherin.

    Science.gov (United States)

    Lecuit, Marc; Nelson, D Michael; Smith, Steve D; Khun, Huot; Huerre, Michel; Vacher-Lavenu, Marie-Cécile; Gordon, Jeffrey I; Cossart, Pascale

    2004-04-20

    Listeria monocytogenes produces severe fetoplacental infections in humans. How it targets and crosses the maternofetal barrier is unknown. We used immunohistochemistry to examine the location of L. monocytogenes in placental and amniotic tissue samples obtained from women with fetoplacental listeriosis. The results raised the possibility that L. monocytogenes crosses the maternofetal barrier through the villous syncytiotrophoblast, with secondary infection occurring via the amniotic epithelium. Because epidemiological studies indicate that the bacterial surface protein, internalin (InlA), may play a role in human fetoplacental listeriosis, we investigated the cellular patterns of expression of its host receptor, E-cadherin, at the maternofetal interface. E-cadherin was found on the basal and apical plasma membranes of syncytiotrophoblasts and in villous cytotrophoblasts. Established trophoblastic cell lines, primary trophoblast cultures, and placental villous explants were each exposed to isogenic InlA+ or InlA- strains of L. monocytogenes, and to L. innocua expressing or not InlA. Quantitative assays of cellular invasion demonstrated that bacterial entry into syncytiotrophoblasts occurs via the apical membrane in an InlA-E-cadherin dependent manner. In human placental villous explants, bacterial invasion of the syncytiotrophoblast barrier and underlying villous tissue and subsequent replication produces histopathological lesions that mimic those seen in placentas of women with listeriosis. Thus, the InlA-E-cadherin interaction that plays a key role in the crossing of the intestinal barrier in humans is also exploited by L. monocytogenes to target and cross the placental barrier. Such a ligand-receptor interaction allowing a pathogen to specifically cross the placental villous trophoblast barrier has not been reported previously.

  12. Phenotypic and Genotypic Analysis of Newly Obtained Interspecific Hybrids in the Campanula Genus.

    Directory of Open Access Journals (Sweden)

    Anna-Catharina Röper

    Full Text Available Interspecific hybridisation creates new phenotypes within several ornamental plant species including the Campanula genus. We have employed phenotypic and genotypic methods to analyse and evaluate interspecific hybridisation among cultivars of four Campanula species, i.e. C. cochleariifolia, C. isophylla, C. medium and C. formanekiana. Hybrids were analysed using amplified fragment length polymorphism (AFLP, flow cytometry and biometrical measurements. Results of correlation matrices demonstrated heterogeneous phenotypes for the parental species, which confirmed our basic premise for new phenotypes of interspecific hybrids. AFLP assays confirmed the hybridity and identified self-pollinated plants. Limitation of flow cytometry analysis detection was observed while detecting the hybridity status of two closely related parents, e.g. C. cochleariiafolia × C. isophylla. Phenotypic characteristics such as shoot habitus and flower colour were strongly influenced by one of the parental species in most crosses. Rooting analysis revealed that inferior rooting quality occurred more often in interspecific hybrids than in the parental species. Only interspecific hybrid lines of C. formanekiana 'White' × C. medium 'Pink' showed a high rooting level. Phenotype analyses demonstrated a separation from the interspecific hybrid lines of C. formanekiana 'White' × C. medium 'Pink' to the other clustered hybrids of C. formanekiana and C. medium. In our study we demonstrated that the use of correlation matrices is a suitable tool for identifying suitable cross material. This study presents a comprehensive overview for analysing newly obtained interspecific hybrids. The chosen methods can be used as guidance for analyses for further interspecific hybrids in Campanula, as well as in other ornamental species.

  13. Food-Derived Hemorphins Cross Intestinal and Blood–Brain Barriers In Vitro

    Directory of Open Access Journals (Sweden)

    Dorothée Domenger

    2018-04-01

    Full Text Available A qualitative study is presented, where the main question was whether food-derived hemorphins, i.e., originating from digested alimentary hemoglobin, could pass the intestinal barrier and/or the blood–brain barrier (BBB. Once absorbed, hemorphins are opioid receptor (OR ligands that may interact with peripheral and central OR and have effects on food intake and energy balance regulation. LLVV-YPWT (LLVV-H4, LVV-H4, VV-H4, VV-YPWTQRF (VV-H7, and VV-H7 hemorphins that were previously identified in the 120 min digest resulting from the simulated gastrointestinal digestion of hemoglobin have been synthesized to be tested in in vitro models of passage of IB and BBB. LC-MS/MS analyses yielded that all hemorphins, except the LLVV-H4 sequence, were able to cross intact the human intestinal epithelium model with Caco-2 cells within 5–60 min when applied at 5 mM. Moreover, all hemorphins crossed intact the human BBB model with brain-like endothelial cells (BLEC within 30 min when applied at 100 µM. Fragments of these hemorphins were also detected, especially the YPWT common tetrapeptide that retains OR-binding capacity. A cAMP assay performed in Caco-2 cells indicates that tested hemorphins behave as OR agonists in these cells by reducing cAMP production. We further provide preliminary results regarding the effects of hemorphins on tight junction proteins, specifically here the claudin-4 that is involved in paracellular permeability. All hemorphins at 100 µM, except the LLVV-H4 peptide, significantly decreased claudin-4 mRNA levels in the Caco-2 intestinal model. This in vitro study is a first step toward demonstrating food-derived hemorphins bioavailability which is in line with the growing body of evidence supporting physiological functions for food-derived peptides.

  14. Interspecific Competition Underlying Mutualistic Networks

    Science.gov (United States)

    Maeng, Seong Eun; Lee, Jae Woo; Lee, Deok-Sun

    2012-03-01

    Multiple classes of interactions may exist affecting one another in a given system. For the mutualistic networks of plants and pollinating animals, it has been known that the degree distribution is broad but often deviates from power-law form more significantly for plants than animals. To illuminate the origin of such asymmetry, we study a model network in which links are assigned under generalized preferential-selection rules between two groups of nodes and find the sensitive dependence of the resulting connectivity pattern on the model parameters. The nonlinearity of preferential selection can come from interspecific interactions among animals and among plants. The model-based analysis of real-world mutualistic networks suggests that a new animal determines its partners not only by their abundance but also under the competition with existing animal species, which leads to the stretched-exponential degree distributions of plants.

  15. Cross-Cultural Differences in Undergraduate Students' Perceptions of Online Barriers

    Science.gov (United States)

    Olesova, Larisa; Yang, Dazhi; Richardson, Jennifer C.

    2011-01-01

    The intent of this study was to learn about students' perceived barriers and the impact of those barriers on the quality of online discussions between two distinct cultural groups in Eastern and Northern Siberia (Russia). A mixed-methods approach utilizing surveys and interviews was used to investigate (1) the types of barriers the students…

  16. Superresolution and Fluorescence Dynamics Evidence Reveal That Intact Liposomes Do Not Cross the Human Skin Barrier.

    Directory of Open Access Journals (Sweden)

    Jes Dreier

    Full Text Available In this study we use the combination of super resolution optical microscopy and raster image correlation spectroscopy (RICS to study the mechanism of action of liposomes as transdermal drug delivery systems in human skin. Two different compositions of liposomes were applied to newly excised human skin, a POPC liposome and a more flexible liposome containing the surfactant sodium cholate. Stimulated emission depletion microscopy (STED images of intact skin and cryo-sections of skin treated with labeled liposomes were recorded displaying an optical resolution low enough to resolve the 100 nm liposomes in the skin. The images revealed that virtually none of the liposomes remained intact beneath the skin surface. RICS two color cross correlation diffusion measurements of double labeled liposomes confirmed these observations. Our results suggest that the liposomes do not act as carriers that transport their cargo directly through the skin barrier, but mainly burst and fuse with the outer lipid layers of the stratum corneum. It was also found that the flexible liposomes showed a greater delivery of the fluorophore into the stratum corneum, indicating that they functioned as chemical permeability enhancers.

  17. The blood-brain barrier: structure, function and therapeutic approaches to cross it.

    Science.gov (United States)

    Tajes, Marta; Ramos-Fernández, Eva; Weng-Jiang, Xian; Bosch-Morató, Mònica; Guivernau, Biuse; Eraso-Pichot, Abel; Salvador, Bertrán; Fernàndez-Busquets, Xavier; Roquer, Jaume; Muñoz, Francisco J

    2014-08-01

    The blood-brain barrier (BBB) is constituted by a specialized vascular endothelium that interacts directly with astrocytes, neurons and pericytes. It protects the brain from the molecules of the systemic circulation but it has to be overcome for the proper treatment of brain cancer, psychiatric disorders or neurodegenerative diseases, which are dramatically increasing as the population ages. In the present work we have revised the current knowledge on the cellular structure of the BBB and the different procedures utilized currently and those proposed to cross it. Chemical modifications of the drugs, such as increasing their lipophilicity, turn them more prone to be internalized in the brain. Other mechanisms are the use of molecular tools to bind the drugs such as small immunoglobulins, liposomes or nanoparticles that will act as Trojan Horses favoring the drug delivery in brain. This fusion of the classical pharmacology with nanotechnology has opened a wide field to many different approaches with promising results to hypothesize that BBB will not be a major problem for the new generation of neuroactive drugs. The present review provides an overview of all state-of-the-art of the BBB structure and function, as well as of the classic strategies and these appeared in recent years to deliver drugs into the brain for the treatment of Central Nervous System (CNS) diseases.

  18. Addressing safety liabilities of TfR bispecific antibodies that cross the blood-brain barrier.

    Science.gov (United States)

    Couch, Jessica A; Yu, Y Joy; Zhang, Yin; Tarrant, Jacqueline M; Fuji, Reina N; Meilandt, William J; Solanoy, Hilda; Tong, Raymond K; Hoyte, Kwame; Luk, Wilman; Lu, Yanmei; Gadkar, Kapil; Prabhu, Saileta; Ordonia, Benjamin A; Nguyen, Quyen; Lin, Yuwen; Lin, Zhonghua; Balazs, Mercedesz; Scearce-Levie, Kimberly; Ernst, James A; Dennis, Mark S; Watts, Ryan J

    2013-05-01

    Bispecific antibodies using the transferrin receptor (TfR) have shown promise for boosting antibody uptake in brain. Nevertheless, there are limited data on the therapeutic properties including safety liabilities that will enable successful development of TfR-based therapeutics. We evaluate TfR/BACE1 bispecific antibody variants in mouse and show that reducing TfR binding affinity improves not only brain uptake but also peripheral exposure and the safety profile of these antibodies. We identify and seek to address liabilities of targeting TfR with antibodies, namely, acute clinical signs and decreased circulating reticulocytes observed after dosing. By eliminating Fc effector function, we ameliorated the acute clinical signs and partially rescued a reduction in reticulocytes. Furthermore, we show that complement mediates a residual decrease in reticulocytes observed after Fc effector function is eliminated. These data raise important safety concerns and potential mitigation strategies for the development of TfR-based therapies that are designed to cross the blood-brain barrier.

  19. Zika Virus Infects, Activates, and Crosses Brain Microvascular Endothelial Cells, without Barrier Disruption

    Science.gov (United States)

    Papa, Michelle P.; Meuren, Lana M.; Coelho, Sharton V. A.; Lucas, Carolina G. de Oliveira; Mustafá, Yasmin M.; Lemos Matassoli, Flavio; Silveira, Paola P.; Frost, Paula S.; Pezzuto, Paula; Ribeiro, Milene R.; Tanuri, Amilcar; Nogueira, Mauricio L.; Campanati, Loraine; Bozza, Marcelo T.; Paula Neto, Heitor A.; Pimentel-Coelho, Pedro M.; Figueiredo, Claudia P.; de Aguiar, Renato S.; de Arruda, Luciana B.

    2017-01-01

    Zika virus (ZIKV) has been associated to central nervous system (CNS) harm, and virus was detected in the brain and cerebrospinal fluids of microcephaly and meningoencephalitis cases. However, the mechanism by which the virus reaches the CNS is unclear. Here, we addressed the effects of ZIKV replication in human brain microvascular endothelial cells (HBMECs), as an in vitro model of blood brain barrier (BBB), and evaluated virus extravasation and BBB integrity in an in vivo mouse experimental model. HBMECs were productively infected by African and Brazilian ZIKV strains (ZIKVMR766 and ZIKVPE243), which induce increased production of type I and type III IFN, inflammatory cytokines and chemokines. Infection with ZIKVMR766 promoted earlier cellular death, in comparison to ZIKVPE243, but infection with either strain did not result in enhanced endothelial permeability. Despite the maintenance of endothelial integrity, infectious virus particles crossed the monolayer by endocytosis/exocytosis-dependent replication pathway or by transcytosis. Remarkably, both viruses' strains infected IFNAR deficient mice, with high viral load being detected in the brains, without BBB disruption, which was only detected at later time points after infection. These data suggest that ZIKV infects and activates endothelial cells, and might reach the CNS through basolateral release, transcytosis or transinfection processes. These findings further improve the current knowledge regarding ZIKV dissemination pathways. PMID:29312238

  20. Heterosis and correlation in interspecific and intraspecific hybrids of cotton.

    Science.gov (United States)

    Munir, S; Hussain, S B; Manzoor, H; Quereshi, M K; Zubair, M; Nouman, W; Shehzad, A N; Rasul, S; Manzoor, S A

    2016-06-24

    Interspecific and intraspecific hybrids show varying degrees of heterosis for yield and yield components. Yield-component traits have complex genetic relationships with each other. To determine the relationship of yield-component traits and fiber traits with seed cotton yield, six lines (Bt. CIM-599, CIM-573, MNH-786, CIM-554, BH-167, and GIZA-7) and three test lines (MNH-886, V4, and CIM-557) were crossed in a line x tester mating design. Heterosis was observed for seed cotton yield, fiber traits, and for other yield-component traits. Heterosis in interspecific hybrids for seed cotton yield was more prominent than in intraspecific hybrids. The interspecific hybrid Giza-7 x MNH-886 had the highest heterosis (114.77), while among intraspecific hybrids, CIM-554 x CIM-557 had the highest heterosis (61.29) for seed cotton yield. A major trait contributing to seed cotton yield was bolls/plant followed by boll weight. Correlation studies revealed that bolls/plant, boll weight, lint weight/boll, lint index, seed index, lint/seed, staple length, and staple strength were significantly and positively associated with seed cotton yield. Selection based on boll weight, boll number, lint weight/boll, and lint index will be helpful for improving cotton seed yield.

  1. Translation, Cross-cultural Adaptation and Psychometric Validation of the Korean-Language Cardiac Rehabilitation Barriers Scale (CRBS-K).

    Science.gov (United States)

    Baek, Sora; Park, Hee-Won; Lee, Yookyung; Grace, Sherry L; Kim, Won-Seok

    2017-10-01

    To perform a translation and cross-cultural adaptation of the Cardiac Rehabilitation Barriers Scale (CRBS) for use in Korea, followed by psychometric validation. The CRBS was developed to assess patients' perception of the degree to which patient, provider and health system-level barriers affect their cardiac rehabilitation (CR) participation. The CRBS consists of 21 items (barriers to adherence) rated on a 5-point Likert scale. The first phase was to translate and cross-culturally adapt the CRBS to the Korean language. After back-translation, both versions were reviewed by a committee. The face validity was assessed in a sample of Korean patients (n=53) with history of acute myocardial infarction that did not participate in CR through semi-structured interviews. The second phase was to assess the construct and criterion validity of the Korean translation as well as internal reliability, through administration of the translated version in 104 patients, principle component analysis with varimax rotation and cross-referencing against CR use, respectively. The length, readability, and clarity of the questionnaire were rated well, demonstrating face validity. Analysis revealed a six-factor solution, demonstrating construct validity. Cronbach's alpha was greater than 0.65. Barriers rated highest included not knowing about CR and not being contacted by a program. The mean CRBS score was significantly higher among non-attendees (2.71±0.26) than CR attendees (2.51±0.18) (pKorea.

  2. Magnetic Nanoparticles Cross the Blood-Brain Barrier: When Physics Rises to a Challenge

    Directory of Open Access Journals (Sweden)

    Maria Antònia Busquets

    2015-12-01

    Full Text Available The blood-brain barrier is a physical and physiological barrier that protects the brain from toxic substances within the bloodstream and helps maintain brain homeostasis. It also represents the main obstacle in the treatment of many diseases of the central nervous system. Among the different approaches employed to overcome this barrier, the use of nanoparticles as a tool to enhance delivery of therapeutic molecules to the brain is particularly promising. There is special interest in the use of magnetic nanoparticles, as their physical characteristics endow them with additional potentially useful properties. Following systemic administration, a magnetic field applied externally can mediate the capacity of magnetic nanoparticles to permeate the blood-brain barrier. Meanwhile, thermal energy released by magnetic nanoparticles under the influence of radiofrequency radiation can modulate blood-brain barrier integrity, increasing its permeability. In this review, we present the strategies that use magnetic nanoparticles, specifically iron oxide nanoparticles, to enhance drug delivery to the brain.

  3. Triple-humped fission barrier model for a new {sup 238}U neutron cross-section evaluation and first validations

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Jimenez, M.J. [CEA/DIF/DPTA/Service de Physique Nucleaire, B.P. 12, F-91680 Bruyeres-le-Chatel (France); Morillon, B. [CEA/DIF/DPTA/Service de Physique Nucleaire, B.P. 12, F-91680 Bruyeres-le-Chatel (France); Romain, P. [CEA/DIF/DPTA/Service de Physique Nucleaire, B.P. 12, F-91680 Bruyeres-le-Chatel (France)]. E-mail: pascal.romain@cea.fr

    2005-01-15

    A new neutron-induced cross-section evaluation of {sup 238}U from 1 keV up to 200 MeV has been performed using only nuclear reactions models. A new fission penetrability model taking into account a triple humped barrier has been developed. A clear improvement has been observed for K-effective validation tests (up to 30 MeV) with this new evaluation. This improvement is mainly due to a better treatment of the inelastic exit channel.

  4. Obtaining of interspecific hybrids for pea introgressive breeding

    Directory of Open Access Journals (Sweden)

    Sergey Vasilevich Bobkov

    2015-09-01

    Full Text Available Background. Overcoming of reproductive isolation, identification and transfer of agronomic value genes from wild relatives into cultivated pea genomes is an important task for pea introgressive breeding. Materials and methods. Reciprocal hybridization of cultivated pea with wide set of P. fulvum accessions was conducted. Identification of hybrids was carried out with use of biochemical and morphological markers. Identification of unique protein was conducted with use of electrophoretic spectra of mature seeds. Results. Pea interspecific hybrids were obtained in two reciprocal directions of crosses. Cross efficiency in Р. sativum × P. fulvum and P. fulvum × Р. sativum combinations was 36 % and 7 %, respectively. All tested seeds in crosses Р. sativum × P. fulvum were hybrids. Crosses in direction P. fulvum × Р. sativum led to formation of puny seeds restricted in embryo growth. Protein markers of one seed derived in cross P. fulvum × Р. sativum proved its hybrid nature. Morphological markers demonstrated that plant derived from another cross was also a hybrid. Culture of immature embryos was developed for recovering plants in interspecific crosses. Morphogenic calli and regenerated plants were obtained in culture of immature embryos P. fulvum (И592589 × Р. sativum (Aest. Identification of unique protein 7 of P. fulvum was conducted. Inheritance of that protein was proved as monogenic dominant. Conclusion. Efficiency of hybridization in combination P. fulvum × Р. sativum was significantly less in compare to reciprocal one. All products of that cross combination were tested as hybrids. Unique protein 7 of P. fulvum was revealed as a result of mature seed electrophoretic spectra analysis. Inheritance of that protein was determined as monogenic dominant.

  5. A cross-sectional study of facilitators and barriers of Iranian nurses' participation in continuing education programs.

    Science.gov (United States)

    Hamzehgardeshi, Zeinab; Shahhosseini, Zohreh

    2013-12-27

    Continuing education is one of the modern strategies to maintain and elevate knowledge and professional skills of nurses which in turn elevate the health status of society. Since several factors affect nurses' participation in continuing education, it's essential to know promoters and obstacles in this issue and plan accordingly. In this cross-sectional study, 361 Iranian nurses who were recruited by convenience sampling method completed an anonymous, self-administered questionnaire from October 2012 to April 2013. Topics covered the participants' attitudes towards facilitators and barriers of their participation in continuing education. Mean and standard deviation of participants ' age were 37.14±7.58 years and 93.94% were female. The maximum score of facilitators and barriers to nurses' participation in continuing education were related to "Update my knowledge" and "Work commitments" respectively. The results showed among Iranian nurses, the mean score of personal and structural barriers was significantly higher than the mean score of interpersonal ones (F=2122.66, peducation programs by enforcement of facilitators and reducing barriers focusing on the personal and structural barriers.

  6. Barrier contraception among adolescents and young adults in a tertiary institution in Southwestern Nigeria: a cross-sectional descriptive study.

    Science.gov (United States)

    Olugbenga-Bello, Adenike I; Adekanle, Daniel A; Ojofeitimi, Ebenezer O; Adeomi, Adeleye A

    2010-01-01

    Nigeria, like most African nations, is basically conservative, but the young people are becoming more sexually liberated, and the incidence of STD/HIV, unwanted pregnancies and abortions among these young people is on the increase. The use of barrier contraception (BC), which is a cost-effective method of preventing STD/HIV, unwanted pregnancies and its attending complications, has therefore become an important issue in reproductive health. This descriptive cross-sectional study was carried out among first year students of Osun State University, Nigeria. Four hundred respondents were studied using pre-tested semi-structured questionnaires. The respondents were selected by balloting. Most respondents (93%) had heard about the male condom as a method of barrier contraception. Most respondents (79.1%) supported the use of barrier contraceptives, but many (62.5%) thought it would promote sexual promiscuity, 33.4% believed that the use of barrier contraception reflected a lack of trust from the partner, and 38.7% felt barrier contraception is not necessary with a stable partner. One hundred and sixty one (40.5%) had used a form of barrier contraception before, but only 130 (32.7%) are currently using BC. The male condom was the most commonly used method (88.2%), followed by female condom and diaphragm (5.6% respectively). The prevention of STI and unwanted pregnancies were the main reasons (59%) given by respondents for using BC, while religion was the main reason given by non-users. The attitudes of these students toward barrier contraception and their practice were poor. The role of sex education at homes and religious gatherings cannot be over-emphasized.

  7. Predictors of perceived barriers to physical activity in the general adult population: a cross-sectional study.

    Science.gov (United States)

    Herazo-Beltrán, Yaneth; Pinillos, Yisel; Vidarte, José; Crissien, Estela; Suarez, Damaris; García, Rafael

    The perception of personal barriers to physical activity varies according to the sociodemographic characteristics of individuals. To determine the predictors of the perception of barriers to physical activity in the adult population. A cross-sectional study with 1066 adult women and 1036 adult men. The sociodemographic variables (age, gender, marital status, socioeconomic level, level of education), the perception of barriers that do not allow performance of physical activity (i.e. lack of time, social support, energy, motivation, skill, resources, and fear of injury during practice); and the level of physical activity through the International Physical Activity Questionnaire in its short-form version were evaluated. Individuals from low socioeconomic level (1 and 2) have higher risks of perceiving barriers such as lack of motivation [OR 1.76 (95% CI (1.4-2.1))] and lack of resources [OR 1.37 (95% CI (1.1-1.6))]; individuals with partners did not perceive the lack of social support [OR 0.29 (95% CI (0.2-0.4))] and lack of motivation [OR 0.54 (95% CI (0.4-0.7))] as barriers to physical activity. Individuals with low schooling perceived lack of social support [OR 3.81 (95% CI (3-4.7))], lack of resources [OR 2.78 (95% CI (2.2-3.3))], and fear of injury [OR 2.70 (95% CI (2.2-3.3))] as barrier to physical activity. Factors such as socioeconomic level, marital status, level of education, and self-perception of health are predictors of barriers to physical activity. Copyright © 2017 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. Publicado por Elsevier Editora Ltda. All rights reserved.

  8. Changes in research on language barriers in health care since 2003: A cross-sectional review study.

    Science.gov (United States)

    Schwei, Rebecca J; Del Pozo, Sam; Agger-Gupta, Niels; Alvarado-Little, Wilma; Bagchi, Ann; Chen, Alice Hm; Diamond, Lisa; Gany, Francesca; Wong, Doreena; Jacobs, Elizabeth A

    2016-02-01

    Understanding how to mitigate language barriers is becoming increasingly important for health care providers around the world. Language barriers adversely affect patients in their access to health services; comprehension and adherence; quality of care; and patient and provider satisfaction. In 2003, the United States (US) government made a major change in national policy guidance that significantly affected limited English proficient patients' ability to access language services. The objectives of this paper are to describe the state of the language barriers literature inside and outside the US since 2003 and to compare the research that was conducted before and after a national policy change occurred in the US. We hypothesize that language barrier research would increase inside and outside the US but that the increase in research would be larger inside the US in response to this national policy change. We reviewed the research literature on language barriers in health care and conducted a cross sectional analysis by tabulating frequencies for geographic location, language group, methodology, research focus and specialty and compared the literature before and after 2003. Our sample included 136 studies prior to 2003 and 426 studies from 2003 to 2010. In the 2003-2010 time period there was a new interest in studying the providers' perspective instead of or in addition to the patients' perspective. The methods remained similar between periods with greater than 60% of studies being descriptive and 12% being interventions. There was an increase in research on language barriers inside and outside the US and we believe this was larger due to the change in the national policy. We suggest that researchers worldwide should move away from simply documenting the existence of language barriers and should begin to focus their research on documenting how language concordant care influences patient outcomes, providing evidence for interventions that mitigate language barriers

  9. Barriers to cross--institutional health information exchange: a literature review.

    Science.gov (United States)

    Edwards, Ashley; Hollin, Ilene; Barry, Jeffrey; Kachnowski, Stan

    2010-01-01

    While the development of health information technology, particularly electronic health records (EHR), is a triumph for the advancement of healthcare, non-interoperable clinical data systems lead to fragmented communication and incomplete records. If interoperable HIT systems could be achieved integrated HIT could be leveraged to lessen medical errors, improve patient care and optimize epidemiological research. To understand the barriers to interoperability or health information exchange (HIE), we reviewed the literature on HIT and barriers to HIE. Our search yielded 492 articles, 25 meeting our inclusion criteria. In general, we found that the predominant barriers to HIE are need for standards, security concerns, economic loss to competitors, and federated systems. Research on interoperability is limited because most HIE programs are still in formative stages. More research is needed to fully understand interoperability of HIT, how to overcome the barriers to interoperability, and how to design HIT to better facilitate HIE.

  10. Barriers to physical activity in older adults in Germany: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Moschny Anna

    2011-11-01

    Full Text Available Abstract Background Data on barriers to physical activity in older adults in Germany are scarce. The aim of this study was to analyse barriers to physical activity in a cohort of older adults, allowing comparisons between men and women, and age groups. Methods 1,937 older adults with a median age of 77 (range 72-93 years (53.3% female took part in the 7-year follow-up telephone interviews of the getABI cohort. Participants who stated that they did not get enough physical activity were surveyed with respect to barriers to physical activity. Barriers were analysed for all respondents, as well as by sex and age group for cases with complete data. Multivariate logistic regression analysis was performed to evaluate differences between sexes and age groups. The level of significance (alpha Results 1,607 (83.0% participants stated that they were sufficiently physically active. 286 participants rated their physical activity as insufficient and responded to questions on barriers to physical activity completely. The three most frequently cited barriers were poor health (57.7%, lack of company (43.0%, and lack of interest (36.7%. Lack of opportunities for sports or leisure activities (30.3% vs. 15.6%, and lack of transport (29.0% vs. 7.1% were more frequently stated by female respondents than male respondents. These differences between men and women were significant (p = .003; p Conclusions The present study provides relevant data on barriers to physical activity in older adults. By revealing appreciable differences between men and women, and age groups, this study has implications for efforts to increase older adults' physical activity. Promotion and intervention strategies should consider the barriers and tailor measures to the specific needs of older adults in order to reduce their constraints to physical activity.

  11. Cancer symptom awareness and barriers to medical help seeking in Scottish adolescents: a cross-sectional study.

    Science.gov (United States)

    Hubbard, Gill; Macmillan, Iona; Canny, Anne; Forbat, Liz; Neal, Richard D; O'Carroll, Ronan E; Haw, Sally; Kyle, Richard G

    2014-10-29

    Initiatives to promote early diagnosis include raising public awareness of signs and symptoms of cancer and addressing barriers to seeking medical help about cancer. Awareness of signs and symptoms of cancer and emotional barriers, such as fear, worry, and embarrassment, strongly influence help seeking behaviour. Whether anxiety influences seeking medical help about cancer is not known. The purpose of this study about adolescents was to examine: 1) the relationship between contextual factors and awareness of signs and symptoms of cancer and barriers (including emotional barriers) to seeking medical help, and 2) associations between anxiety and endorsed barriers to seeking medical help. Interpretation of data is informed by the common sense model of the self-regulation of health and illness. A cross-sectional study of 2,173 Scottish adolescents (age 12/13 years) using the Cancer Awareness Measure. Socio-demographic questions were also included. Descriptive statistics were calculated and two Poisson regression models were built to determine independent predictors of: 1) the number of cancer warning signs recognized, and; 2) number of barriers to help seeking endorsed. Analysis identified that knowing someone with cancer was a significant independent predictor of recognising more cancer warning signs whereas Black and Minority Ethnic status was a significant independent predictor of recognising fewer cancer warning signs. Emotional barriers were the most commonly endorsed, followed by family, service and practical barriers. Over two thirds of adolescents were 'worried about what the doctor would find' and over half were 'scared'. Higher anxiety scores, knowing more cancer warning signs and female gender were significant independent predictors of barriers to help seeking. Improving cancer awareness and help seeking behaviour during adolescence may contribute to early presentation. Contextual factors (for example, ethnicity, gender, knowing someone with cancer), and

  12. Development of inter-specific chromosomes segment substitution libraries (CSSL) in rice

    Science.gov (United States)

    Six libraries of inter-specific Chromosome Segment Substitution Lines (CSSLs) of rice are being developed as pre-breeding materials and genetic stocks. Three accessions of O. rufipogon were selected as donors, based on phylogenetic, geographical and morphological divergence, and crossed with two rec...

  13. Barriers to women's participation in inter-conceptional care: a cross-sectional analysis

    Directory of Open Access Journals (Sweden)

    Hogan Vijaya K

    2012-02-01

    Full Text Available Abstract Background We describe participation rates in a special interconceptional care program that addressed all commonly known barriers to care, and identify predictors of the observed levels of participation in this preventive care service. Methods A secondary analysis of data from women in the intervention arm of an interconceptional care clinical trial in Philadelphia (n = 442. Gelberg-Andersen Behavioral Model for Vulnerable Populations to Health Services (herein called Andersen model was used as a theoretical base. We used a multinomial logit model to analyze the factors influencing women's level of participation in this enhanced interconceptional care program. Results Although common barriers were addressed, there was variable participation in the interconceptional interventions. The Andersen model did not explain the variation in interconceptional care participation (Wald ch sq = 49, p = 0.45. Enabling factors (p = 0.058, older maternal age (p = 0.03 and smoking (p = were independently associated with participation. Conclusions Actively removing common barriers to care does not guarantee the long-term and consistent participation of vulnerable women in preventive care. There are unknown factors beyond known barriers that affect participation in interconceptional care. New paradigms are needed to identify the additional factors that serve as barriers to participation in preventive care for vulnerable women.

  14. Psychosocial problems and barriers to improved diabetes management: results of the Cross-National Diabetes Attitudes, Wishes and Needs (DAWN) Study

    NARCIS (Netherlands)

    Peyrot, M.; Rubin, R.R.; Lauritzen, T.; Snoek, F.J.; Matthews, D.R.; Skovlund, S.E.

    2005-01-01

    Aims: To examine patient- and provider-reported psychosocial problems and barriers to effective self-care and resources for dealing with those barriers. Methods: Cross-sectional study using face-to-face or telephone interviews with diabetic patients and health-care providers in 13 countries in Asia,

  15. Breeding of lilies and tulips—Interspecific hybridization and genetic background—

    Science.gov (United States)

    Marasek-Ciolakowska, Agnieszka; Nishikawa, Tomotaro; Shea, Daniel J.; Okazaki, Keiichi

    2018-01-01

    Lilies and tulips (Liliaceae family) are economically very important ornamental bulbous plants. Here, we summarize major breeding goals, the role of an integrated method of cut-style pollination and fertilization followed by embryo rescue and mitotic and meiotic polyploidization involved in new assortment development. Both crops have been subjected to extensive interspecific hybridization followed by selection. Additionally, spontaneous polyploidization has played a role in their evolution. In lilies, there is a tendency to replace diploids with polyploid cultivars, whereas in tulip a majority of the cultivars that exist today are still diploid except for triploid Darwin hybrid tulips. The introduction of molecular cytogenetic techniques such as genomic in situ hybridization (GISH) permitted the detailed studies of genome composition in lily and tulip interspecific hybrids and to follow the chromosome inheritance in interspecific crosses. In addition, this review presents the latest information on phylogenetic relationship in lily and tulip and recent developments in molecular mapping using different DNA molecular techniques. PMID:29681746

  16. Treatment gap and barriers for mental health care: A cross-sectional community survey in Nepal.

    Directory of Open Access Journals (Sweden)

    Nagendra P Luitel

    Full Text Available There is limited research on the gap between the burden of mental disorders and treatment use in low- and middle-income countries.The aim of this study was to assess the treatment gap among adults with depressive disorder (DD and alcohol use disorder (AUD and to examine possible barriers to initiation and continuation of mental health treatment in Nepal.A three-stage sampling technique was used in the study to select 1,983 adults from 10 Village Development Committees (VDCs of Chitwan district. Presence of DD and AUD were identified with validated versions of the Patient Health Questionnaire (PHQ-9 and Alcohol Use Disorder Identification Test (AUDIT. Barriers to care were assessed with the Barriers to Access to Care Evaluation (BACE.In this sample, 11.2% (N = 228 and 5.0% (N = 96 screened positive for DD and AUD respectively. Among those scoring above clinical cut-off thresholds, few had received treatment from any providers; 8.1% for DD and 5.1% for AUD in the past 12 months, and only 1.8% (DD and 1.3% (AUD sought treatment from primary health care facilities. The major reported barriers to treatment were lacking financial means to afford care, fear of being perceived as "weak" for having mental health problems, fear of being perceived as "crazy" and being too unwell to ask for help. Barriers to care did not differ based on demographic characteristics such as age, sex, marital status, education, or caste/ethnicity.With more than 90% of the respondents with DD or AUD not participating in treatment, it is crucial to identify avenues to promote help seeking and uptake of treatment. Given that demographic characteristics did not influence barriers to care, it may be possible to pursue general population-wide approaches to promoting service use.

  17. Extreme endurance flights by landbirds crossing the Pacific Ocean : Ecological corridor rather than barrier?

    NARCIS (Netherlands)

    Gill, Robert E.; Tibbitts, T. Lee; Douglas, David C.; Handel, Colleen M.; Mulcahy, Daniel M.; Gottschalck, Jon C.; Warnock, Nils; McCaffery, Brian J.; Battley, Philip F.; Piersma, Theunis

    2009-01-01

    Mountain ranges, deserts, ice fields and oceans generally act as barriers to the movement of land-dependent animals, often profoundly shaping migration routes. We used satellite telemetry to track the southward flights of bar-tailed godwits (Limosa lapponica baueri), shorebirds whose breeding and

  18. Buckling of thermally fluctuating spherical shells: Parameter renormalization and thermally activated barrier crossing

    Science.gov (United States)

    Baumgarten, Lorenz; Kierfeld, Jan

    2018-05-01

    We study the influence of thermal fluctuations on the buckling behavior of thin elastic capsules with spherical rest shape. Above a critical uniform pressure, an elastic capsule becomes mechanically unstable and spontaneously buckles into a shape with an axisymmetric dimple. Thermal fluctuations affect the buckling instability by two mechanisms. On the one hand, thermal fluctuations can renormalize the capsule's elastic properties and its pressure because of anharmonic couplings between normal displacement modes of different wavelengths. This effectively lowers its critical buckling pressure [Košmrlj and Nelson, Phys. Rev. X 7, 011002 (2017), 10.1103/PhysRevX.7.011002]. On the other hand, buckled shapes are energetically favorable already at pressures below the classical buckling pressure. At these pressures, however, buckling requires to overcome an energy barrier, which only vanishes at the critical buckling pressure. In the presence of thermal fluctuations, the capsule can spontaneously overcome an energy barrier of the order of the thermal energy by thermal activation already at pressures below the critical buckling pressure. We revisit parameter renormalization by thermal fluctuations and formulate a buckling criterion based on scale-dependent renormalized parameters to obtain a temperature-dependent critical buckling pressure. Then we quantify the pressure-dependent energy barrier for buckling below the critical buckling pressure using numerical energy minimization and analytical arguments. This allows us to obtain the temperature-dependent critical pressure for buckling by thermal activation over this energy barrier. Remarkably, both parameter renormalization and thermal activation lead to the same parameter dependence of the critical buckling pressure on temperature, capsule radius and thickness, and Young's modulus. Finally, we study the combined effect of parameter renormalization and thermal activation by using renormalized parameters for the energy

  19. A processing plant persistent strain of Listeria monocytogenes crosses the fetoplacental barrier in a pregnant guinea pig model

    DEFF Research Database (Denmark)

    Jensen, Anne; Williams, D.; Irving, E. A.

    2008-01-01

    independent fish processing plants. The purpose of the present study was to determine the virulence potential of one RAPD type 9 strain (La111), one human clinical strain (Scott A), and one monkey clinical strain (12443) in a pregnant guinea pig model. Animals were orally exposed to 10(8) CFU of L...... was isolated from 16 and 20% of placentas for 12443 and La111, respectively. The study demonstrates that a food processing plant persistent strain of L. monocytogenes is able to cross the fetoplacental barrier in pregnant guinea pigs. Furthermore, we demonstrate that although information can be gained from...

  20. Barriers to gene flow in interspecific hybridization in Fuchsia L ...

    Indian Academy of Sciences (India)

    from the poor pollen germination on the stigma to arrested pollen tube ..... stored in 70% ethanol until required. The pistils ... A total of 1495 flowers were pollinated in 125 combinations. (including ... 'Gartenmeister Bonstedt' as the female parent. Despite ... centage of unfilled seeds ranged from 30 per cent to 71 per cent. In ...

  1. Molecular markers unravel intraspecific and interspecific genetic ...

    Indian Academy of Sciences (India)

    [Kotwal S., Dhar M. K., Kour B., Raj K. and Kaul S. 2013 Molecular markers unravel intraspecific and interspecific genetic variability in ... of bowel problems including chronic constipation, amoebic ..... while to select parents from accessions, Pov80 and Pov79 ... nology (DBT), Govt. of India, for financial assistance in the form.

  2. Interspecific nest use by aridland birds

    Science.gov (United States)

    Deborah M. Finch

    1982-01-01

    Nest holes drilled by woodpeckers (Picidae) are frequently used by secondary cavity-nesting species, but interspecific use of open and domed nests is less well known. Nests constructed by many southwestern desert birds last longer than one year (pers. obs.) and are consequently reused by the same pair (e.g., Abert's Towhees [Pipilo aberti], pers. obs.) or by other...

  3. Asymmetric interspecific territorial competition over food resources ...

    African Journals Online (AJOL)

    The rock-dwelling cichlids in Lake Malawi comprise the most diverse freshwater fish community in the world. Individuals frequently interact with heterospecifics through feeding territoriality. Underwater observations and experiments were conducted to examine interspecific variation in the frequencies of territorial behaviour ...

  4. Apparatus and method of manufacture for an imager equipped with a cross-talk barrier

    Science.gov (United States)

    Pain, Bedabrata (Inventor)

    2012-01-01

    An imager apparatus and associated starting material are provided. In one embodiment, an imager is provided including a silicon layer of a first conductivity type acting as a junction anode. Such silicon layer is adapted to convert light to photoelectrons. Also included is a semiconductor well of a second conductivity type formed in the silicon layer for acting as a junction cathode. Still yet, a barrier is formed adjacent to the semiconductor well. In another embodiment, a starting material is provided including a first silicon layer and an oxide layer disposed adjacent to the first silicon layer. Also included is a second silicon layer disposed adjacent to the oxide layer opposite the first silicon layer. Such second silicon layer is further equipped with an associated passivation layer and/or barrier.

  5. Exploration of barriers to breast-self examination among urban women in Shah Alam, Malaysia: a cross sectional study.

    Science.gov (United States)

    Al-Dubai, Sami Abdo Radman; Ganasegeran, Kurubaran; Alabsi, Aied M; Abdul Manaf, Mohd Rizal; Ijaz, Sharea; Kassim, Saba

    2012-01-01

    Breast cancer is the most common cancer among women in Malaysia. Barriers for practicing breast self examination (BSE) await exploration. To assess the practice of BSE and its correlated factors and particularly barriers amongst urban women in Malaysia. This cross-sectional study was conducted with 222 Malaysian women using a self-administered questionnaire. The mean (SD) age was 28.5 (±9.2) years, 59.0% were university graduates. Of the total, 81.1% were aware of breast cancer and 55% practiced BSE. Amongst 45% of respondents who did not practice BSE, 79.8% did not know how to do it, 60.6% feared being diagnosed with breast cancer, 59.6% were worried about detecting breast cancer, 22% reported that they should not touch their bodies, 44% and 28% reported BSE is embarrassing or unpleasant, 29% time consuming, 22% thought they would never have breast cancer or it is ineffective and finally 20% perceived BSE as unimportant. Logistic regression modeling showed that respondents aged ≥45 years, being Malay, married and having a high education level were more likely to practice BSE (pcultural, perception and environmental factors were identified as barriers. BSE practice was associated significantly with socio-demographic factors and socioeconomic status.

  6. Effect of skin barrier disruption on immune responses to topically applied cross-reacting material, CRM(197), of diphtheria toxin.

    Science.gov (United States)

    Godefroy, S; Peyre, M; Garcia, N; Muller, S; Sesardic, D; Partidos, C D

    2005-08-01

    The high accessibility of the skin and the presence of immunocompetent cells in the epidermis makes this surface an attractive route for needle-free administration of vaccines. However, the lining of the skin by the stratum corneum is a major obstacle to vaccine delivery. In this study we examined the effect of skin barrier disruption on the immune responses to the cross-reacting material CRM(197), a nontoxic mutant of diphtheria toxin (DTx) that is considered as a vaccine candidate. Application of CRM(197), together with cholera toxin (CT), onto the tape-stripped skin of mice elicited antibody responses that had anti-DTx neutralizing activity. Vaccine delivery onto mildly ablated skin or intact skin did not elicit any detectable anti-CRM(197) antibodies. Mice immunized with CRM(197) alone onto the tape-stripped skin mounted a vigorous antigen-specific proliferative response. In contrast, the induction of cellular immunity after CRM(197) deposition onto mildly ablated or intact skin was adjuvant dependent. Furthermore, epidermal cells were activated and underwent apoptosis that was more pronounced when the stratum corneum was removed by tape stripping. Overall, these findings highlight the potential for transcutaneous delivery of CRM(197) and establish a correlation between the degree of barrier disruption and levels of antigen-specific immune responses. Moreover, these results provide the first evidence that the development of a transcutaneous immunization strategy for diphtheria, based on simple and practical methods to disrupt the skin barrier, is feasible.

  7. Anti-transferrin receptor antibody and antibody-drug conjugates cross the blood-brain barrier

    International Nuclear Information System (INIS)

    Friden, P.M.; Walus, L.R.; Musso, G.F.; Taylor, M.A.; Malfroy, B.; Starzyk, R.M.

    1991-01-01

    Delivery of nonlipophilic drugs to the brain is hindered by the tightly apposed capillary endothelial cells that make up the blood-brain barrier. The authors have examined the ability of a monoclonal antibody (OX-26), which recognizes the rat transferrin receptor, to function as a carrier for the delivery of drugs across the blood-brain barrier. This antibody, which was previously shown to bind preferentially to capillary endothelial cells in the brain after intravenous administration, labels the entire cerebrovascular bed in a dose-dependent manner. The initially uniform labeling of brain capillaries becomes extremely punctate ∼ 4 hr after injection, suggesting a time-dependent sequestering of the antibody. Capillary-depletion experiments, in which the brain is separated into capillary and parenchymal fractions, show a time-dependent migration of radiolabeled antibody from the capillaries into the brain parenchyma, which is consistent with the transcytosis of compounds across the blood-brain barrier. Antibody-methotrexate conjugates were tested in vivo to assess the carrier ability of this antibody. Immunohistochemical staining for either component of an OX-26-methotrexate conjugate revealed patterns of cerebrovascular labeling identical to those observed with the unaltered antibody. Accumulation of radiolabeled methotrexate in the brain parenchyma is greatly enhanced when the drug is conjugated to OX-26

  8. Interspecific gene flow and maintenance of species integrity in oaks

    Directory of Open Access Journals (Sweden)

    Oliver Gailing

    2014-07-01

    Full Text Available Oak species show a wide variation in morphological and physiological characters, and species boundaries between closely related species are often not clear-cut. Still, despite frequent interspecific gene flow, oaks maintain distinct morphological and physiological adaptations. In sympatric stands, spatial distribution of species with different ecological requirements is not random but constrained by soil and other microenvironmental factors. Pre-zygotic isolation (e.g. cross incompatibilities, asynchrony in flowering, pollen competition and post-zygotic isolation (divergent selection contribute to the maintenance of species integrity in sympatric oak stands. The antagonistic effects of interspecific gene flow and divergent selection are reflected in the low genetic differentiation between hybridizing oak species at most genomic regions interspersed by regions with signatures of divergent selection (outlier regions. In the near future, the availability of high-density genetic linkage maps anchored to scaffolds of a sequenced Q. robur genome will allow to characterize the underlying genes in these outlier regions and their putative role in reproductive isolation between species. Reciprocal transplant experiments of seedlings between parental environments can be used to characterize selection on outlier genes. High transferability of gene-based markers will enable comparative outlier screens in different oak species.

  9. A cross-sectional analysis of barriers to health-care seeking among medical students across training period

    Directory of Open Access Journals (Sweden)

    Vikas Menon

    2017-01-01

    Full Text Available Background and Aims: Very little information is available on how needs and perceptions to service utilization may change with duration of medical training. Our objective was to compare the self-reported barriers to health-care seeking for mental and physical health services separately between 1st year and final year medical students. Methods: In this cross-sectional study, we invited all medical students of the concerned cohorts to complete a prevalidated checklist and 28-item self-reported questionnaire about perceived barriers to health-care seeking. The questionnaire had separate items pertaining to usage of mental and physical health-care services. Results: The response rate of the 1st year and final year cohorts were 83.8% and 86.6%, respectively. Lack of time, unawareness about where to seek help, cost issues, and fear of future academic jeopardy were more common concerns among 1st year students to the usage of mental health services (odds ratio [OR] 0.27, 0.45,0.09, and 0.49, respectively whereas issues of stigma were more commonly reported by final year students for using mental health services (OR = 2.87. In contrast, the barriers in using physical health services were broadly comparable between the two cohorts. Conclusion: Differences exist between medical students in various years of training particularly with regard to self-reported barriers and perceptions particularly about using mental health-care services. This may have key implications for designing and delivery of service provisions in this group.

  10. Multiple barriers to participation for people with psychosocial disability in Dehradun district, North India: a cross-sectional study.

    Science.gov (United States)

    Mathias, Kaaren; Pant, Hira; Marella, Manjula; Singh, Lawrence; Murthy, Gvs; Grills, Nathan

    2018-02-27

    This study used a population-based cross-sectional survey to describe the prevalence of psychosocial disability and unmet need for access to services in North India. This study was conducted in Dehradun district, Uttarakhand, in 2014. A population-based sample of 2441 people over the age of 18 years. The Rapid Assessment of Disability survey tool identified people with disability and used an adapted version of the Kessler scale to identify those with psychosocial disability. It additionally collected information on socioeconomic variables, access to community services and barriers to participation. Prevalence of psychosocial disability and unmet needs and descriptions of barriers to services were calculated, and multivariable logistic regression was used to assess associations between risk factors and psychosocial disability. Prevalence of psychosocial disability was 4.8% and 75% of participants with psychological distress also reported comorbid functional impairments. Adjusted ORs for depression of more than two were found for people who were unschooled, unemployed and of moderate or poor socioeconomic status. The unmet need for access to services was significantly higher in every domain for people with psychosocial disability and was more than 25% in the areas of employment, health service access and community consultation. People with psychosocial disability encountered greater barriers in each domain compared with controls. People who are poor, uneducated and unemployed are two to four times more likely to have psychosocial disability in Dehradun district. They face unmet needs in accessing community services and perceive negative social attitudes, lack of physical accessibility and lack of information as barriers limiting their participation. Social policy must increase access to education and reduce poverty but additionally ensure action is taken in all community services to increase information, physical accessibility and social inclusion of people with

  11. Attitudes, experiences, and barriers to research and publishing among dental postgraduate students of Bengaluru City: A cross-sectional study

    Directory of Open Access Journals (Sweden)

    Aditi Hegde

    2017-01-01

    Full Text Available Background: Research experience not only enhances understanding but also instills evidence-based practice and improves skills. A natural successor to research is academic publishing. Unfortunately, student research itself is plagued by a number of barriers. Aim: To identify the attitudes, experiences, and barriers to research and publishing among dental postgraduate students of Bangalore city. Materials and Methods: A cross-sectional survey using purposive sampling technique was conducted among the dental postgraduate students of all specialties in Bengaluru city in the months of July–August 2015. A prevalidated, close-ended, self-administered questionnaire consisting of 26 questions was used. Data from 638 completed questionnaires were entered into and analyzed using Microsoft Excel 2013 and SPSS software version 14. Results: The majority of the students displayed a positive attitude towards research and stated that they would like more opportunities to take part in research (89%. Most students were positive toward publishing research; 94% agreed that it is important to publish, although only 43.7% had submitted an article for publication. The single most often stated barrier to conducting research was a lack of funding from the institution (15.7%, followed by workload and time constraints (15.0%. Lack of training and good mentorship was the most often (23.3% faced barrier to publishing, along with high publication fee for indexed journals (17.9%. Conclusion: Dental postgraduate students show an urge to conduct research and publish their results. Research-related workshops for teachers and students are suggestions for improving the status of research in dental colleges.

  12. A cross sectional survey of the barriers for implementing rapid HIV testing among French general practitioners.

    Science.gov (United States)

    Fraisse, Thibaut; Fourcade, Camille; Brazes-Sanz, Julie; Koumar, Yatrika; Lavigne, Jean Philippe; Sotto, Albert; Laureillard, Didier

    2016-10-01

    In France, almost 30,000 people are unaware of their HIV-positive status. Innovative screening strategies are essential to reach this population. The aim of this study was to describe the acceptability of rapid HIV testing (RHT) among French general practitioners (GPs) working in the south of France and barriers for implementing this strategy. We analysed an anonymous questionnaire sent by mail to GPs about demographic data, routine practice, knowledge of RHT and barriers to its use. Between 1 April and 30 September 2013, out of the 165 GPs contacted, 78 returned the questionnaires. The GPs' mean age was 52 years; 49 were men. Fifty-one GPs reported that their registered patients included at least one HIV-infected person and 70 GPs reported taking care of high-risk patients. Sixty-three percent of GPs reported being interested in using RHT in their daily practice. The main reasons reported by uninterested GPs were: greater confidence in standard HIV testing, difficulties including RHT during the routine consultation, difficulties to screen for other sexually transmitted infections simultaneously, and difficulties to deliver a positive result. French National Authorities for Health propose to screen the population at least once in their lifetime and high-risk people at least once a year. In order to achieve this aim, RHT should be included in the GPs' arsenal for HIV testing. We showed a high acceptability of RHT by GPs. If specific and adapted training is developed, and if solutions to barriers reported by GPs are found, RHT could be implemented in to their routine activity. © The Author(s) 2016.

  13. 14N + 10B fusion and elastic scattering cross section measurements near the interaction barrier

    International Nuclear Information System (INIS)

    Wu, S.C.; Overley, J.C.; Barnes, C.A.; Switkowski, Z.E.

    1979-01-01

    The 14 N + 10 B fusion reactions were studied at c.m. energies between 2.9 and 7.5 MeV by measuring the yields of γ-rays from the residual nuclei formed by particle evaporation from the compound system. Cross sections for formation of the evaporation residues 16 O, 19 F, 19 Ne, 20 Ne, 21 Ne, 22 Ne, 22 Na, 23 Na and 23 Mg, as well as the total cross section, were deduced from these yields with the aid of statistical model calculations. 14 N + 10 B elastic scattering differential cross sections were measured from 4.3 to 9.1 MeV at THETA 74.4 degrees, and from 3.3 to 8.3 MeV at THETA = 90.0 degrees. The elastic scattering cross sections were analyzed within the framework of the incoming-wave boundary condition (IWBC) model. The fusion cross sections calculated for the real ion-ion potential deduced from the IWBC model fit to the elastic scattering are in good agreement with the measured values

  14. Genetic analysis of post-mating reproductive barriers in hybridizing European Populus species.

    Science.gov (United States)

    Macaya-Sanz, D; Suter, L; Joseph, J; Barbará, T; Alba, N; González-Martínez, S C; Widmer, A; Lexer, C

    2011-10-01

    Molecular genetic analyses of experimental crosses provide important information on the strength and nature of post-mating barriers to gene exchange between divergent populations, which are topics of great interest to evolutionary geneticists and breeders. Although not a trivial task in long-lived organisms such as trees, experimental interspecific recombinants can sometimes be created through controlled crosses involving natural F(1)'s. Here, we used this approach to understand the genetics of post-mating isolation and barriers to introgression in Populus alba and Populus tremula, two ecologically divergent, hybridizing forest trees. We studied 86 interspecific backcross (BC(1)) progeny and >350 individuals from natural populations of these species for up to 98 nuclear genetic markers, including microsatellites, indels and single nucleotide polymorphisms, and inferred the origin of the cytoplasm of the cross with plastid DNA. Genetic analysis of the BC(1) revealed extensive segregation distortions on six chromosomes, and >90% of these (12 out of 13) favored P. tremula donor alleles in the heterospecific genomic background. Since selection was documented during early diploid stages of the progeny, this surprising result was attributed to epistasis, cyto-nuclear coadaptation, heterozygote advantage at nuclear loci experiencing introgression or a combination of these. Our results indicate that gene flow across 'porous' species barriers affects these poplars and aspens beyond neutral, Mendelian expectations and suggests the mechanisms responsible. Contrary to expectations, the Populus sex determination region is not protected from introgression. Understanding the population dynamics of the Populus sex determination region will require tests based on natural interspecific hybrid zones.

  15. Characterization of F1 interspecific hybrids between wild Helianthus annuus L. populations and cultivated sunflower

    Directory of Open Access Journals (Sweden)

    Terzić Sreten

    2006-01-01

    Full Text Available Phenotype, chromosomes pairing and pollen vitality were compared between parental populations and F1 hybrids of interspecific cross between Helianthus annuus L. and cultivated sunflower. The investigation of the simple sequence repeats (SSR polymorphism was also used to test the hybrid nature of F1 populations. The phenotypic traits of F1 hybrid plants were either closer to the wild species or intermediate. Irregular chromosome pairing was found in only 0 to 10% of meiocytes in the meiosis of F1 hybrid plants. Interspecific crosses were confirmed with SSR markers in all hybrid combinations. Alleles that were not present in parental DNA were frequently observed in F1 hybrids. That is additional evidence that those hybrid combinations were not produced by self-fertilization. The results suggest that SSR markers can be efficiently used for the F1 hybrid characterization in crosses between closely related species, in which, the changes of phenotype, meiosis and pollen vitality are not always significant.

  16. Extreme endurance flights by landbirds crossing the Pacific Ocean: Ecological corridor rather than barrier?

    Science.gov (United States)

    Gill, Robert E.; Tibbitts, T.L.; Douglas, David C.; Handel, Colleen M.; Mulcahy, D.M.; Gottschalck, J.C.; Warnock, N.; McCaffery, B.J.; Battley, Phil F.; Piersma, Theunis

    2009-01-01

    Mountain ranges, deserts, ice fields and oceans generally act as barriers to the movement of land-dependent animals, often profoundly shaping migration routes. We used satellite telemetry to track the southward flights of bar-tailed godwits (Limosa lapponica baueri), shorebirds whose breeding and non-breeding areas are separated by the vast central Pacific Ocean. Seven females with surgically implanted transmitters flew non-stop 8117-11680km (10153??1043 s.d.) directly across the Pacific Ocean; two males with external transmitters flew non-stop along the same corridor for 7008-7390km. Flight duration ranged from 6.0 to 9.4 days (7.8??1.3 s.d.) for birds with implants and 5.0 to 6.6 days for birds with externally attached transmitters. These extraordinary non-stop flights establish new extremes for avian flight performance, have profound implications for understanding the physiological capabilities of vertebrates and how birds navigate, and challenge current physiological paradigms on topics such as sleep, dehydration and phenotypic flexibility. Predicted changes in climatic systems may affect survival rates if weather conditions at their departure hub or along the migration corridor should change. We propose that this transoceanic route may function as an ecological corridor rather than a barrier, providing a wind-assisted passage relatively free of pathogens and predators. ?? 2008 The Royal Society.

  17. Obtaining interspecific hybrids, and molecular analysis by microsatellite markers in grapevine

    Directory of Open Access Journals (Sweden)

    Mariane Ruzza Schuck

    2011-11-01

    Full Text Available The objective of this work was to assess the potential of interspecific hybridization of Vitis labruscana and Muscadinia rotundifolia by using artificial cross-pollinations. Microsatellite markers were used to confirm interspecific hybridizations and the identity of the parental genotypes. In crosses in which M. rotundifolia was used as the female parent, no true hybrids were obtained. In the reciprocal crosses, 114 seedlings were identified as true V. labruscana x M. rotundifolia hybrids. Self pollination occurred in direct and in reciprocal crosses. The crossings between 'Bordo' x 'Carlos', 'Magnolia', 'Regale' and' Roanoke', and between' Isabel' x 'Bountiful', 'Carlos', 'Magnolia', 'Regale' and 'Roanoke' were confirmed. The 15 markers evaluated showed that two M. rotundifolia parental genotypes had the same fingerprint profile, indicating a like lyplanting error. The success of hybridization depends mainly on the species and on the cultivar used as the female parent. Microsatellite markers are efficient to confirm the paternity of interspecific F1 hybrids and to determine the correct identity of M. rotundifolia cultivars.

  18. Does self-compassion mitigate the relationship between burnout and barriers to compassion? A cross-sectional quantitative study of 799 nurses.

    Science.gov (United States)

    Dev, Vinayak; Fernando, Antonio T; Lim, Anecita Gigi; Consedine, Nathan S

    2018-05-01

    Burnout has numerous negative consequences for nurses, potentially impairing their ability to deliver compassionate patient care. However, the association between burnout and compassion and, more specifically, barriers to compassion in medicine is unclear. This article evaluates the associations between burnout and barriers to compassion and examines whether dispositional self-compassion might mitigate this association. Consistent with prior work, the authors expected greater burnout to predict greater barriers to compassion. We also expected self-compassion - the ability to be kind to the self during times of distress - to weaken the association between burnout and barriers to compassion among nurses. Registered nurses working in New Zealand medical contexts were recruited using non-random convenience sampling. Following consent, 799 valid participants completed a cross-sectional survey including the Copenhagen Burnout Inventory, the Barriers to Physician Compassion scale, and a measure of dispositional self-compassion. As expected, greater burnout predicted greater barriers to compassion while self-compassion predicted fewer barriers. However, self-compassion mitigated the association between burnout and burnout related barriers to compassion (but not other barriers). The interaction suggested that suggested that the association was stronger (rather than weaker) among those with greater self-compassion. Understanding the lack of compassion and the effects of burnout in patient care are priorities in health. This report extends evidence on the association between burnout and compassion-fatigue to show that burnout also predicts the experience of specific barriers to compassion. While self-compassion predicted lower burnout and barriers, it may not necessarily reduce the extent to which burnout contributes to the experience of barriers to compassion in medicine. Implications for understanding how burnout manifests in barriers to clinical compassion, interventions

  19. Carbenoxolone does not cross the blood brain barrier: an HPLC study

    Directory of Open Access Journals (Sweden)

    Burnham William M

    2006-01-01

    Full Text Available Abstract Background Carbenoxolone (CBX is a widely used gap junctional blocker. Considering several reports indicating that transient gap junctional blockade could be a favourable intervention following injuries to central nervous tissue, and some current enthusiasm in studies using systemic injections of CBX, it is imperative to consider the penetration of CBX into central nervous tissue after systemic administrations. So far, only very indirect evidence suggests that CBX penetrates into the central nervous system after systemic administrations. We thus determined the amounts of CBX present in the blood and the cerebrospinal fluid of rats after intraperitoneal administration, using high performance liquid chromatography Results CBX was found in the blood of the animals, up to 90 minutes post-injection. However, the cerebrospinal fluid concentration of CBX was negligible. Conclusion Thus, we conclude that, most likely, CBX does not penetrate the blood brain barrier and therefore recommend careful consideration in the manner of administration, when a central effect is desired.

  20. Fusion cross sections for 6,7Li + 24Mg at energies around the barrier

    International Nuclear Information System (INIS)

    Ray, Maitreyi; Pradhan, M.K.; Kshetri, R.; Mukherjee, A.; Saha Sarkar, M.; Biswas, M.; Roy, S.; Basu, P.; Majumdar, H.; Dasmahapatra, B.; Sinha, M.; Palit, R.; Mazumdar, I.; Joshi, P.K.; Jain, H.C.

    2006-01-01

    The 6,7 Li + 24 Mg reactions in the energy interval E lab = 11-32 MeV using 6,7 Li beams have been investigated from the 14 UD BARC-TIFR Pelletron accelerator at TIFR, Mumbai. The γ-ray cross sections were measured using a Compton suppressed clover detector, placed at 55 deg with respect to the beam direction

  1. Theranostic quantum dots for crossing blood–brain barrier in vitro and providing therapy of HIV-associated encephalopathy

    Science.gov (United States)

    Xu, Gaixia; Mahajan, Supriya; Roy, Indrajit; Yong, Ken-Tye

    2013-01-01

    The blood–brain barrier (BBB) is a complex physiological checkpoint that restricts the free diffusion of circulating molecules from the blood into the central nervous system. Delivering of drugs and other active agents across the BBB is one of the major technical challenges faced by scientists and medical practitioners. Therefore, development of novel methodologies to address this challenge holds the key for both the diagnosis and treatment of brain diseases, such as HIV-associated encephalopathy. Bioconjugated quantum dots (QDs) are excellent fluorescent probes and nano-vectors, being designed to transverse across the BBB and visualize drug delivery inside the brain. This paper discusses the use of functionalized QDs for crossing the blood–brain barrier and treating brain disease. We highlight the guidelines for using in vitro BBB models for brain disease studies. The theranostic QDs offers a strategy to significantly improve the effective dosages of drugs to transverse across the BBB and orientate to the targets inside the brain. PMID:24298256

  2. Exploring leadership roles, goals, and barriers among Kansas registered nurses: a descriptive cross-sectional study.

    Science.gov (United States)

    Peltzer, Jill N; Ford, Debra J; Shen, Qiuhua; Fischgrund, Avery; Teel, Cynthia S; Pierce, Janet; Jamison, Marian; Waldon, Trynn

    2015-01-01

    The Institute of Medicine's Future of Nursing report advocates for full nurse leader representation across multiple settings to address current challenges in our health care system. The purpose of this study was to examine nursing leadership development needs among Kansas registered nurses (RNs). Data were collected through an online survey and analyzed using quantitative and qualitative methods. Nearly 1,000 Kansas RNs participated. Most reported holding one or more leadership positions. Prevalent leadership goals were health care organization volunteer administrative roles. The most frequently identified barrier to developing leadership roles was time constraints. Many wanted to develop skills to serve on a board, 20% were interested in personal leadership development, and 19% in policy development. Based on the findings, the Kansas Action Coalition leadership team is developing programs to address the leadership needs of Kansas RNs. By building capacity in advanced leadership roles, RNs will be better prepared serve as full partners and lead efforts to promote the health of Kansans. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Gamma irradiation of the interspecific hybrids Gossypium hirsutum L. x G. barbadense L. Part 1

    International Nuclear Information System (INIS)

    Stoilova, A.

    1990-01-01

    The study was aimed at combining the methods of hybridization and experimental mutagenesis and widening the possibilities of interspecific hybridization for successful breeding work. The reaction of interspecific cotton hybrids (G. hirsutum x G. barbadense) to gamma rays in the year of treatment was investigated. Four hybrid combinations resulting from reciprocal crosses between the two species were studied. Seeds of long fibre F 1 plants from each combination were divided in four equal parts (irradiated with 15, 20 and 25 krad and a control). The changes in the main biometrical indices between the control and maximum dose (25 krad) treatment showed that the F 2 hybrids were either resistant or slightly sensitive to irradiation depending on the direction of crossing in respect to growth processes, field germination and survival to the end of vegetation. 3 tabs., 2 figs., 14 refs

  4. Feline APOBEC3s, Barriers to Cross-Species Transmission of FIV?

    Directory of Open Access Journals (Sweden)

    Zeli Zhang

    2018-04-01

    Full Text Available The replication of lentiviruses highly depends on host cellular factors, which defines their species-specific tropism. Cellular restriction factors that can inhibit lentiviral replication were recently identified. Feline immunodeficiency virus (FIV was found to be sensitive to several feline cellular restriction factors, such as apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like 3 (APOBEC3 and tetherin, but FIV evolved to counteract them. Here, we describe the molecular mechanisms by which feline APOBEC3 restriction factors inhibit FIV replication and discuss the molecular interaction of APOBEC3 proteins with the viral antagonizing protein Vif. We speculate that feline APOBEC3 proteins could explain some of the observed FIV cross-species transmissions described in wild Felids.

  5. Superresolution and Fluorescence Dynamics Evidence Reveal That Intact Liposomes Do Not Cross the Human Skin Barrier

    DEFF Research Database (Denmark)

    Dreier, Jes; Sørensen, Jens A; Brewer, Jonathan R

    2016-01-01

    In this study we use the combination of super resolution optical microscopy and raster image correlation spectroscopy (RICS) to study the mechanism of action of liposomes as transdermal drug delivery systems in human skin. Two different compositions of liposomes were applied to newly excised human...... skin, a POPC liposome and a more flexible liposome containing the surfactant sodium cholate. Stimulated emission depletion microscopy (STED) images of intact skin and cryo-sections of skin treated with labeled liposomes were recorded displaying an optical resolution low enough to resolve the 100 nm...... liposomes in the skin. The images revealed that virtually none of the liposomes remained intact beneath the skin surface. RICS two color cross correlation diffusion measurements of double labeled liposomes confirmed these observations. Our results suggest that the liposomes do not act as carriers...

  6. Feline APOBEC3s, Barriers to Cross-Species Transmission of FIV?

    Science.gov (United States)

    Zhang, Zeli; Gu, Qinyong; Marino, Daniela; Lee, Kyeong-Lim; Kong, Il-Keun; Häussinger, Dieter; Münk, Carsten

    2018-01-01

    The replication of lentiviruses highly depends on host cellular factors, which defines their species-specific tropism. Cellular restriction factors that can inhibit lentiviral replication were recently identified. Feline immunodeficiency virus (FIV) was found to be sensitive to several feline cellular restriction factors, such as apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like 3 (APOBEC3) and tetherin, but FIV evolved to counteract them. Here, we describe the molecular mechanisms by which feline APOBEC3 restriction factors inhibit FIV replication and discuss the molecular interaction of APOBEC3 proteins with the viral antagonizing protein Vif. We speculate that feline APOBEC3 proteins could explain some of the observed FIV cross-species transmissions described in wild Felids. PMID:29642583

  7. Genetic Linkage Map Construction and QTL Analysis of Two Interspecific Reproductive Isolation Traits in Sponge Gourd

    OpenAIRE

    Wu, Haibin; He, Xiaoli; Gong, Hao; Luo, Shaobo; Li, Mingzhu; Chen, Junqiu; Zhang, Changyuan; Yu, Ting; Huang, Wangping; Luo, Jianning

    2016-01-01

    The hybrids between Luffa acutangula (L.) Roxb. and L.cylindrica (L.) Roem. have strong heterosis effects. However, some reproductive isolation traits hindered their normal hybridization and fructification, which was mainly caused by the flowering time and hybrid pollen sterility. In order to study the genetic basis of two interspecific reproductive isolation traits, we constructed a genetic linkage map using an F2 population derived from a cross between S1174 [L. acutangula (L.) Roxb.] and 9...

  8. Inter-specific competitive stress does not affect the magnitude of inbreeding depression

    OpenAIRE

    Willi, Yvonne; Dietrich, Stefan; van Kleunen, Mark; Fischer, Markus

    2007-01-01

    Hypothesis: Stressful inter-specific competition enhances inbreeding depression.Organisms: Creeping spearwort (Ranunculus reptans L.) and its common competitor, thecreeping bentgrass (Agrostis stolonifera L.).Field site: Outdoor common garden experiment at the University of Potsdam.Methods: We collected plants of 12 natural populations of R. reptans differing in mean parental inbreeding coefficient (0.01–0.26). We performed within-population crosses for twogenerations and kept the offspring i...

  9. Molecular profiling of interspecific lowland rice populations derived ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-03

    Dec 3, 2008 ... Molecular profiling of interspecific lowland rice populations ... Both cluster and principal component analyses revealed two major groups ...... simulations. Theor ... inheritance, chromosomal location, and population dynamics.

  10. The Columbia River plume as cross-shelf exporter and along-coast barrier

    Science.gov (United States)

    Banas, N. S.; MacCready, P.; Hickey, B. M.

    2009-01-01

    An intensive Lagrangian particle-tracking analysis of the July 2004 upwelling period was conducted in a hindcast model of the US Pacific Northwest coast, in order to determine the effect of the Columbia River plume on the fate of upwelled water. The model, implemented using Regional Ocean Modeling System (ROMS), includes variable wind and atmospheric forcing, variable Columbia river flow, realistic boundary conditions from Navy Coastal Ocean Model (NCOM), and 10 tidal constituents. Model skill has been demonstrated in detail elsewhere [MacCready, P., Banas, N.S., Hickey, B.M., Dever, E.P., Liu, Y., 2008. A model study of tide- and wind-induced mixing in the Columbia River estuary and plume. Continental Shelf Research, this issue, doi:10.1016/j.csr.2008.03.015]. Particles were released in the Columbia estuary, along the Washington coastal wall, and along the model's northern boundary at 48°N. Particles were tracked in three dimensions, using both velocities from ROMS and a vertical random displacement representing turbulent mixing. When 25 h of upwelling flow is looped and particles tracked for 12 d, their trajectories highlight a field of transient eddies and recirculations on scales from 5 to 50 km both north and south of the Columbia. Not all of these features are caused by plume dynamics, but the presence of the plume increases the entrainment of inner-shelf water into them. The cumulative effect of the plume's interaction with these transient features is to increase cross-shelf dispersion: 25% more water is transported laterally past the 100 m isobath when river and estuarine effects are included than when they are omitted. This cross-shelf dispersion also disrupts the southward transport of water along the inner shelf that occurs in the model when the Columbia River is omitted. This second effect—increased retention of upwelled water on the Washington shelf—may be partly responsible for the regional-scale alongcoast gradient in chlorophyll biomass

  11. Comparative intra-and inter-specific sexual organ reciprocity in four distylous Primula species in the Himalaya-Hengduan Mountains.

    Science.gov (United States)

    Li, Hai-Dong; Ren, Zong-Xin; Zhou, Wei; Bernhardt, Peter; Zhao, Yan-Hui; Wu, Zhi-Kun; Li, De-Zhu; Wang, Hong

    2018-04-23

    Distyly is a mechanism promoting cross-pollination within a balanced polymorphism. Numerous studies show that the degree of inter-morph sexual organ reciprocity (SOR) within species relates to its pollen-mediated gene flow. Similarly, a lower inter-specific SOR should promote inter-specific isolation when congeners are sympatric, co-blooming, and share pollinators. In this comparative study, we address the significance of SOR at both intra- and inter-specific levels. Seventeen allopatric and eight sympatric populations representing four Primula species (P. anisodora, P. beesiana, P. bulleyana and P. poissonii) native to the Himalaya-Hengduan Mountains were measured for eight floral traits in both long- and short-styled morphs. GLMM and spatial overlap methods were used to compare intra- and inter-specific SOR. While floral morphology differed among four Primula species. SOR within species was generally higher than between species, but species pairs P. poissonii / P. anisodora and P. beesiana / P. bulleyana, the SOR was high at both intra- and inter-specific levels. We didn't detect a significant variation in intra-specific SOR or inter-specific SOR when compare allopatric vs. sympatric populations for all species studied. As intra-specific SOR increased, disassortative mating may be promoted. As inter-specific SOR decreased, inter-specific isolation between co-flowering species pairs also may increase. Hybridization between congeners occurred when inter-specific SOR increased in sympatric populations was confirmed in two species pairs, P. poissonii / P. anisodora and P. beesiana / P. bulleyana. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  12. Barriers to Exercise in Younger and Older Non-Exercising Adult Women: A Cross Sectional Study in London, United Kingdom

    OpenAIRE

    Ansari, Walid El; Lovell, Geoff

    2009-01-01

    A survey of 100 women in the south of London, United Kingdom (UK) compared exercise barrier intensities between non-exercising younger (20-27 years) and older (28-35 years) adult women; and examined childcare duties as perceived barriers to exercise. Perceived barriers to exercise were examined using an Exercise Benefits/Barriers Scale (EBBS) comprising four subscales (exercise milieu; time expenditure; physical exertion; family discouragement). Participants’ number of children was also noted...

  13. Interspecific hybridization among cultivars of hardy Hibiscus species section Muenchhusia

    DEFF Research Database (Denmark)

    Kuligowska, Katarzyna; Lütken, Henrik Vlk; Christensen, Brian

    2016-01-01

    Rose mallows belong to the Muenchhusia section of the Hibiscus genus. They represent a small group of cold tolerant North American plants and are popular ornamentals mainly because of their abundant, large and colorful flowers. Due to their geographical origin they are well suited for garden use...... in temperate regions worldwide. The aim of the study was to investigate hybridization barriers in crosses among cultivars of Hibiscus species from the Muenchhusia section: H. coccineus, H. laevis and H. moscheutos. Crossing barriers were identified as both pre- and post-zygotic. The analysis of pollen tube...

  14. Dual-pump CARS measurements in a hydrogen diffusion flame in cross-flow with AC dielectric barrier discharge

    Science.gov (United States)

    Nishihara, Munetake; Freund, Jonathan B.; Glumac, Nick G.; Elliott, Gregory S.

    2018-03-01

    This paper presents dual-pump coherent anti-Stokes Raman scattering (CARS) measurements for simultaneous detection of flow temperature and relative concentration, applied to the characterization of a discharge-coupled reacting jet in a cross flow. The diagnostic is hydrogen Q-branch based, providing a much wider dynamic range compared to detection in the S-branch. For a previously developed dielectric barrier discharge, aligned co-axially with the fuel jet, OH planar laser induced fluorescence measurements show that the disturbance in the flame boundary leads to mixing enhancement. The H2-N2 dual-pump CARS measurement was used to map two-dimensional temperature distributions. The increase of the maximum temperature was up to 300 K, with 50% more H2 consumption, providing the reason for the decrease in the flame length by 25%. The increase of the relative H2O-H2 fraction was accompanied with a temperature increase, which indicates local equivalence ratios of below 1. The H2-O2 dual-pump measurements confirmed that the fuel-oxidizer ratios remain in the fuel-lean side at most of the probed locations.

  15. Investigation of the effect of dielectric barrier discharge plasma actuators on the radar cross section of an object

    International Nuclear Information System (INIS)

    Wolf, S; Arjomandi, M

    2011-01-01

    The application of dielectric barrier discharge (DBD) plasma as an electromagnetic absorber was investigated by determining the radar cross section (RCS) of a rectangular, flat plate with a DBD plasma actuator array installed on one of its sides. In order to justify the experimental results, the expected effect of plasma actuation on RCS was analysed by determining the attenuation effect of the plasma with the Lorentz model. Due to the very limited life time of the free electrons and the small extent of the plasma sheath, the attenuation was found to be only minimal. The theoretical results have been verified by comparing the measured RCS values of a plate with and without plasma actuation applied on it in a high-frequency anechoic lab. As expected, no significant influence of DBD plasma on RCS was detected. In addition, it was found that the high voltage power supply used as a part of DBD circuitry produced a high level of disturbance even in the microwave range.

  16. Investigation of the effect of dielectric barrier discharge plasma actuators on the radar cross section of an object

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, S; Arjomandi, M [University of Adelaide, Adelaide, South Australia, 5005 (Australia)

    2011-08-10

    The application of dielectric barrier discharge (DBD) plasma as an electromagnetic absorber was investigated by determining the radar cross section (RCS) of a rectangular, flat plate with a DBD plasma actuator array installed on one of its sides. In order to justify the experimental results, the expected effect of plasma actuation on RCS was analysed by determining the attenuation effect of the plasma with the Lorentz model. Due to the very limited life time of the free electrons and the small extent of the plasma sheath, the attenuation was found to be only minimal. The theoretical results have been verified by comparing the measured RCS values of a plate with and without plasma actuation applied on it in a high-frequency anechoic lab. As expected, no significant influence of DBD plasma on RCS was detected. In addition, it was found that the high voltage power supply used as a part of DBD circuitry produced a high level of disturbance even in the microwave range.

  17. Age of Barrier Canyon-style rock art constrained by cross-cutting relations and luminescence dating techniques.

    Science.gov (United States)

    Pederson, Joel L; Chapot, Melissa S; Simms, Steven R; Sohbati, Reza; Rittenour, Tammy M; Murray, Andrew S; Cox, Gary

    2014-09-09

    Rock art compels interest from both researchers and a broader public, inspiring many hypotheses about its cultural origin and meaning, but it is notoriously difficult to date numerically. Barrier Canyon-style (BCS) pictographs of the Colorado Plateau are among the most debated examples; hypotheses about its age span the entire Holocene epoch and previous attempts at direct radiocarbon dating have failed. We provide multiple age constraints through the use of cross-cutting relations and new and broadly applicable approaches in optically stimulated luminescence dating at the Great Gallery panel, the type section of BCS art in Canyonlands National Park, southeastern Utah. Alluvial chronostratigraphy constrains the burial and exhumation of the alcove containing the panel, and limits are also set by our related research dating both a rockfall that removed some figures and the rock's exposure duration before that time. Results provide a maximum possible age, a minimum age, and an exposure time window for the creation of the Great Gallery panel, respectively. The only prior hypothesis not disproven is a late Archaic origin for BCS rock art, although our age result of A.D. ∼ 1-1100 coincides better with the transition to and rise of the subsequent Fremont culture. This chronology is for the type locality only, and variability in the age of other sites is likely. Nevertheless, results suggest that BCS rock art represents an artistic tradition that spanned cultures and the transition from foraging to farming in the region.

  18. Mobile and cordless telephones, serum transthyretin and the blood-cerebrospinal fluid barrier: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Carlberg Michael

    2009-04-01

    Full Text Available Abstract Background Whether low-intensity radiofrequency radiation damages the blood-brain barrier has long been debated, but little or no consideration has been given to the blood-cerebrospinal fluid barrier. In this cross-sectional study we tested whether long-term and/or short-term use of wireless telephones was associated with changes in the serum transthyretin level, indicating altered transthyretin concentration in the cerebrospinal fluid, possibly reflecting an effect of radiation. Methods One thousand subjects, 500 of each sex aged 18–65 years, were randomly recruited using the population registry. Data on wireless telephone use were assessed by a postal questionnaire and blood samples were analyzed for serum transthyretin concentrations determined by standard immunonephelometric techniques on a BN Prospec® instrument. Results The response rate was 31.4%. Logistic regression of dichotomized TTR serum levels with a cut-point of 0.31 g/l on wireless telephone use yielded increased odds ratios that were statistically not significant. Linear regression of time since first use overall and on the day that blood was withdrawn gave different results for males and females: for men significantly higher serum concentrations of TTR were seen the longer an analogue telephone or a mobile and cordless desktop telephone combined had been used, and in contrast, significantly lower serum levels were seen the longer an UMTS telephone had been used. Adjustment for fractions of use of the different telephone types did not modify the effect for cumulative use or years since first use for mobile telephone and DECT, combined. For women, linear regression gave a significant association for short-term use of mobile and cordless telephones combined, indicating that the sooner blood was withdrawn after the most recent telephone call, the higher the expected transthyretin concentration. Conclusion In this hypothesis-generating descriptive study time since first

  19. Barriers to using skilled birth attendants' services in mid- and far-western Nepal: a cross-sectional study.

    Science.gov (United States)

    Choulagai, Bishnu; Onta, Sharad; Subedi, Narayan; Mehata, Suresh; Bhandari, Gajananda P; Poudyal, Amod; Shrestha, Binjwala; Mathai, Matthews; Petzold, Max; Krettek, Alexandra

    2013-12-23

    Skilled birth attendants (SBAs) provide important interventions that improve maternal and neonatal health and reduce maternal and neonatal mortality. However, utilization and coverage of services by SBAs remain poor, especially in rural and remote areas of Nepal. This study examined the characteristics associated with utilization of SBA services in mid- and far-western Nepal. This cross-sectional study examined three rural and remote districts of mid- and far-western Nepal (i.e., Kanchanpur, Dailekh and Bajhang), representing three ecological zones (southern plains [Tarai], hill and mountain, respectively) with low utilization of services by SBAs. Enumerators assisted a total of 2,481 women. All respondents had delivered a baby within the past 12 months. We used bivariate and multivariate analyses to assess the association between antenatal and delivery care visits and the women's background characteristics. Fifty-seven percent of study participants had completed at least four antenatal care visits and 48% delivered their babies with the assistance of SBAs. Knowing the danger signs of pregnancy and delivery (e.g., premature labor, prolonged labor, breech delivery, postpartum hemorrhage, severe headache) associated positively with four or more antenatal care visits (OR = 1.71; 95% CI: 1.41-2.07). Living less than 30 min from a health facility associated positively with increased use of both antenatal care (OR = 1.44; 95% CI: 1.18-1.77) and delivery services (OR = 1.25; CI: 1.03-1.52). Four or more antenatal care visits was a determining factor for the utilization of SBAs. Less than half of the women in our study delivered babies with the aid of SBAs, indicating a need to increase utilization of such services in rural and remote areas of Nepal. Distance from health facilities and inadequate transportation pose major barriers to the utilization of SBAs. Providing women with transportation funds before they go to a facility for delivery and managing transportation

  20. Crossing the Salt Barrier

    Indian Academy of Sciences (India)

    either the sea or freshwater (rivers, lakes, ponds, etc.), or brackish ... by use of the term osmol (Osm) where, for ... much lower than EE and a fresh water fish lives in an environment where just ..... than prophyropsin, vision is greatly improved.

  1. Barriers to Exercise in Younger and Older Non-Exercising Adult Women: A Cross Sectional Study in London, United Kingdom

    Science.gov (United States)

    Ansari, Walid El; Lovell, Geoff

    2009-01-01

    A survey of 100 women in the south of London, United Kingdom (UK) compared exercise barrier intensities between non-exercising younger (20–27 years) and older (28–35 years) adult women; and examined childcare duties as perceived barriers to exercise. Perceived barriers to exercise were examined using an Exercise Benefits/Barriers Scale (EBBS) comprising four subscales (exercise milieu; time expenditure; physical exertion; family discouragement). Participants’ number of children was also noted. Non-exercising older women reported significantly higher total exercise barriers, as well as across three barrier subscales: exercise milieu, time expenditure, and family discouragement. For both age groups, significant correlation existed between number of children and women’s total exercise barrier scores. Number of children explained ≈25% and ≈30% of the variance of younger and older women’s total barrier scores respectively. For both women groups, the strongest correlation between exercise barrier and number of children was for the time expenditure subscale. Broad grouping of 20–35 year old non-exercising women does not reflect a homogenous sample. Age categories employing narrower age brackets are recommended. Issues surrounding family responsibilities e.g. childcare duties may be shared between these groups and require further research and policy attention. PMID:19440527

  2. Barriers to Exercise in Younger and Older Non-Exercising Adult Women: A Cross Sectional Study in London, United Kingdom

    Directory of Open Access Journals (Sweden)

    Geoff Lovell

    2009-04-01

    Full Text Available A survey of 100 women in the south of London, United Kingdom (UK compared exercise barrier intensities between non-exercising younger (20-27 years and older (28-35 years adult women; and examined childcare duties as perceived barriers to exercise. Perceived barriers to exercise were examined using an Exercise Benefits/Barriers Scale (EBBS comprising four subscales (exercise milieu; time expenditure; physical exertion; family discouragement. Participants’ number of children was also noted. Non-exercising older women reported significantly higher total exercise barriers, as well as across three barrier subscales: exercise milieu, time expenditure, and family discouragement. For both age groups, significant correlation existed between number of children and women’s total exercise barrier scores. Number of children explained »25% and »30% of the variance of younger and older women’s total barrier scores respectively. For both women groups, the strongest correlation between exercise barrier and number of children was for the time expenditure subscale. Broad grouping of 20-35 year old non-exercising women does not reflect a homogenous sample. Age categories employing narrower age brackets are recommended. Issues surrounding family responsibilities e.g. childcare duties may be shared between these groups and require further research and policy attention.

  3. Barriers to exercise in younger and older non-exercising adult women: a cross sectional study in London, United Kingdom.

    Science.gov (United States)

    El Ansari, Walid; Lovell, Geoff

    2009-04-01

    A survey of 100 women in the south of London, United Kingdom (UK) compared exercise barrier intensities between non-exercising younger (20-27 years) and older (28-35 years) adult women; and examined childcare duties as perceived barriers to exercise. Perceived barriers to exercise were examined using an Exercise Benefits/Barriers Scale (EBBS) comprising four subscales (exercise milieu; time expenditure; physical exertion; family discouragement). Participants' number of children was also noted. Non-exercising older women reported significantly higher total exercise barriers, as well as across three barrier subscales: exercise milieu, time expenditure, and family discouragement. For both age groups, significant correlation existed between number of children and women's total exercise barrier scores. Number of children explained approximately 25% and approximately 30% of the variance of younger and older women's total barrier scores respectively. For both women groups, the strongest correlation between exercise barrier and number of children was for the time expenditure subscale. Broad grouping of 20-35 year old non-exercising women does not reflect a homogenous sample. Age categories employing narrower age brackets are recommended. Issues surrounding family responsibilities e.g. childcare duties may be shared between these groups and require further research and policy attention.

  4. Molecular phylogeny of the genus Asparagus (Asparagaceae) explains interspecific crossability between the garden asparagus (A. officinalis) and other Asparagus species.

    Science.gov (United States)

    Kubota, Shosei; Konno, Itaru; Kanno, Akira

    2012-02-01

    The genus Asparagus comprises approximately 200 species, some of which are commercially cultivated, such as the garden asparagus (A. officinalis). Many Asparagus species, including A. officinalis, are dioecious and have been grouped into a subgenus distinct from that of hermaphroditic species. Although many interspecific crossings have been attempted to introduce useful traits into A. officinalis, only some of the dioecious species were found to be cross-compatible with A. officinalis. Here, molecular phylogenetic analyses were conducted to determine whether interspecific crossability is proportional to the genetic distance between the crossing pairs and to further clarify the evolutionary history of the Asparagus genus. A clade with all cross-compatible species and no cross-incompatible species was recovered in the phylogenetic tree based on analyses of non-coding cpDNA regions. In addition, a sex-linked marker developed for A. officinalis amplified a male-specific region in all cross-compatible species. The phylogenetic analyses also provided some insights about the evolutionary history of Asparagus; for example, by indicating that the genus had its origin in southern Africa, subsequently spreading throughout the old world through intensive speciation and dispersal. The results also suggest that dioecious species were derived from a single evolutionary transition from hermaphroditism in Asparagus. These findings not only contribute towards the understanding of the evolutionary history of the genus but may also facilitate future interspecific hybridization programs involving Asparagus species.

  5. Nursing and midwifery use, perceptions and barriers to evidence-based practice: a cross-sectional survey.

    Science.gov (United States)

    Fry, Margaret; Attawet, Jutharat

    2018-03-01

    The study aimed to explore how nurses and midwives obtain, use and embed evidence in everyday practice. The study design was cross-sectional survey method. The setting was one local health district in metropolitan Sydney, Australia. All nurses and midwives working within the local health district, with access to an email account, were invited to participate in the study. An online survey questionnaire was distributed to explore how evidence is obtained, used and embedded within the clinical setting. The data were analysed using descriptive statistics (frequency and percentages). Pearson's Chi-square tests were used for comparison between groups. There were 204 survey respondents. The findings identified that the majority (n = 157; 76.96%) of respondents obtained evidence primarily from clinical practice guidelines. The majority (n = 149; 73.04%) of respondents reportedly searched databases and used evidence related to general clinical practice. There was a statistical difference (χ = 17.069; df = 8; P = 0.029) when comparing leadership positions and other registered practitioner groups in the frequency of searching for evidence. Most respondents (n = 138; 67.65%) were confident in their ability to change practice on the basis of available evidence. Thematic analysis identified four barriers to sustaining evidence-based practice, which included: the need for time; the need for organizational and management support; the need for educational opportunities and challenges to accessing evidence. The study provided an understanding of how nurses and midwives obtain, use and embed evidence into everyday practice. More importantly, the role of leadership is significant to support a process of knowledge generation, research translation and the implementation of evidence into clinical settings.

  6. Perceived Barriers to Healthy Eating and Physical Activity among Adolescents in Seven Arab Countries: A Cross-Cultural Study

    Directory of Open Access Journals (Sweden)

    Abdulrahman O. Musaiger

    2013-01-01

    Full Text Available Objective. To highlight the perceived personal, social, and environmental barriers to healthy eating and physical activity among Arab adolescents. Method. A multistage stratified sampling method was used to select 4698 students aged 15–18 years (2240 males and 2458 females from public schools. Seven Arab counties were included in the study, namely, Algeria, Jordan, Kuwait, Libya, Palestine, Syria, and the United Arab Emirates. Self-reported questionnaire was used to list the barriers to healthy eating and physical activity facing these adolescents. Results. It was found that lack of information on healthy eating, lack of motivation to eat a healthy diet, and not having time to prepare or eat healthy food were the main barriers to healthy eating among both genders. For physical activity, the main barriers selected were lack of motivation to do physical activity, less support from teachers, and lack of time to do physical activity. In general, females faced more barriers to physical activity than males in all countries included. There were significant differences between males and females within each country and among countries for most barriers. Conclusion. Intervention programmes to combat obesity and other chronic noncommunicable diseases in the Arab world should include solutions to overcome the barriers to weight maintenance, particularly the sociocultural barriers to practising physical activity.

  7. Interspecific hybrids between Paspalum plicatulum and P. oteroi: a key tool for forage breeding

    Directory of Open Access Journals (Sweden)

    Patricia Elda Novo

    2016-08-01

    Full Text Available ABSTRACT Grama-tio-pedro (Paspalum oteroi Swallen is a rare stoloniferous grass of the Plicatula group of Paspalum, well adapted to continuous grazing in areas subject to seasonal flooding in the Pantanal region, in central western Brazil. The species is a facultative apomictic (asexual reproduction by seed tetraploid, sporadically cultivated on Pantanal farms, propagated either by cuttings or seed. Due to its potential for extensive cultivation and forage quality, Grama-tio-pedro appears as a candidate for genetic improvement within the Plicatula group through plant breeding. We used a colchicine-induced sexual autotetraploid genotype of P. plicatulum Michx. to obtain interspecific hybrids using the apomictic species, P. oteroi, as pollen donor. The very similar meiotic chromosome behavior observed in both parents, with main quadrivalent and bivalent associations, suggested that P. oteroi is a natural autotetraploid. The hybrids showed less irregular meiotic behavior with fewer quadrivalents and more bivalents than either parent. Fertility among interspecific hybrids varied from complete sterility in some of them to seed productions in others that were approximately twice as much as for either parent. The great variability of seed set performance may well be a drastic genetic consequence of joining two homologous chromosome sets of P. plicatulum together with two homologous sets of P. oteroi that, in turn, have some homeology between them. Most hybrids reproduce by sexual means, thus, they could be used as female parents in backcrosses and in crosses with other species of the Plicatula group for interspecific gene transferring in breeding programs.

  8. Phenology of the oil palm interspecific hybrid Elaeis oleifera × Elaeis guineensis

    Directory of Open Access Journals (Sweden)

    Paola Hormaza

    2012-01-01

    Full Text Available Oil palm is one of the most important oil crops in the world. Because of its high productivity and perennial nature, it has been expanding quickly. Commercial plantations consist mostly of the African palm E. guineensis Jacq. However, producers in Latin America are increasingly planting the O × G interspecific hybrid, a cross between African palm (E. guineensis and the American palm (E. oleifera (Kunth Cortés. This interspecific hybrid has emerged as a promising solution to diseases such as the bud rot of oil palm because of the apparent partial resistance of this genotype to the disease. This work studied and described the phenology of the O × G interspecific hybrid. The phenology stages were coded using the BBCH scale. The scale for the phenophases was defined using a three-digit code. Due to the nature of the palm, no descriptions were used for stage two (formation of side shoots/tillering and stage four (development of harvestable vegetative plant parts or vegetative reproductive organs because these stages do not apply to oil palm. The scale was constructed using germinating seeds, pre-nursery and nursery plants and five year-old palms. For the description of the stem elongation, different age palms of the same O × G hybrid were used. Observations were performed during an 18-month period. Additionally, the interval for the change from one phenology stage to another was determined both in days and degree-days (DD. The interspecific O × G hybrid required 6408 DD from when the spear leaf unfolds until the bunch was ripened and harvested, and 4427.6 DD from leaf unfolding to anthesis.

  9. Evolutionary and Ecological Consequences of Interspecific Hybridization in Cladocerans

    NARCIS (Netherlands)

    Schwenk, K.; Spaak, P.

    1995-01-01

    The evolutionary process of interspecific hybridization in cladocerans is reviewed based on ecological and population genetic data. The evolutionary consequences of hybridization, biogeographic patterns and fitness comparisons are analyzed within the conceptual framework of theories on

  10. Meiotic behaviour in three interspecific three-way hybrids between ...

    Indian Academy of Sciences (India)

    The meiotic behaviour of three three-way interspecific promising hybrids (H17, H27, and H34) was evaluated. ... Arrangement of parental genomes in distinct ... vanna due to its physiological tolerance to low fertility acid ... nomic evaluations.

  11. Cancer symptom awareness and barriers to medical help seeking in Scottish adolescents: a cross-sectional study

    OpenAIRE

    Hubbard, Gill; Macmillan, Iona; Canny, Anne; Forbat, Liz; Neal, Richard D; O’Carroll, Ronan E; Haw, Sally; Kyle, Richard G

    2014-01-01

    Background Initiatives to promote early diagnosis include raising public awareness of signs and symptoms of cancer and addressing barriers to seeking medical help about cancer. Awareness of signs and symptoms of cancer and emotional barriers, such as, fear, worry, and embarrassment strongly influence help seeking behaviour. Whether anxiety influences seeking medical help about cancer is not known. The purpose of this study about adolescents was to examine: 1) the relationship between contextu...

  12. Prairie dogs increase fitness by killing interspecific competitors.

    Science.gov (United States)

    Hoogland, John L; Brown, Charles R

    2016-03-30

    Interspecific competition commonly selects for divergence in ecology, morphology or physiology, but direct observation of interspecific competition under natural conditions is difficult. Herbivorous white-tailed prairie dogs (Cynomys leucurus) employ an unusual strategy to reduce interspecific competition: they kill, but do not consume, herbivorous Wyoming ground squirrels (Urocitellus elegans) encountered in the prairie dog territories. Results from a 6-year study in Colorado, USA, revealed that interspecific killing of ground squirrels by prairie dogs was common, involving 47 different killers; 19 prairie dogs were serial killers in the same or consecutive years, and 30% of female prairie dogs killed at least one ground squirrel over their lifetimes. Females that killed ground squirrels had significantly higher annual and lifetime fitness than non-killers, probably because of decreased interspecific competition for vegetation. Our results document the first case of interspecific killing of competing individuals unrelated to predation (IK) among herbivorous mammals in the wild, and show that IK enhances fitness for animals living under natural conditions. © 2016 The Author(s).

  13. Unified theory of interspecific allometric scaling

    International Nuclear Information System (INIS)

    Silva, Jafferson K L da; Barbosa, Lauro A; Silva, Paulo Roberto

    2007-01-01

    A general simple theory for the interspecific allometric scaling is developed in the d + 1-dimensional space (d biological lengths and a physiological time) of metabolic states of organisms. It is assumed that natural selection shaped the metabolic states in such a way that the mass and energy d + 1-densities are size-invariant quantities (independent of body mass). The different metabolic states (basal and maximum) are described by considering that the biological lengths and the physiological time are related by different transport processes of energy and mass. In the basal metabolism, transportation occurs by ballistic and diffusion processes. In d = 3, the 3/4 law occurs if the ballistic movement is the dominant process, while the 2/3 law appears when both transport processes are equivalent. Accelerated movement during the biological time is related to the maximum aerobic sustained metabolism, which is characterized by the scaling exponent 2d/(2d + 1) (6/7 in d = 3). The results are in good agreement with empirical data and a verifiable empirical prediction about the aorta blood velocity in maximum metabolic rate conditions is made. (fast track communication)

  14. Introducing a new breed of wine yeast: interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast and Saccharomyces mikatae.

    Science.gov (United States)

    Bellon, Jennifer R; Schmid, Frank; Capone, Dimitra L; Dunn, Barbara L; Chambers, Paul J

    2013-01-01

    Interspecific hybrids are commonplace in agriculture and horticulture; bread wheat and grapefruit are but two examples. The benefits derived from interspecific hybridisation include the potential of generating advantageous transgressive phenotypes. This paper describes the generation of a new breed of wine yeast by interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast strain and Saccharomyces mikatae, a species hitherto not associated with industrial fermentation environs. While commercially available wine yeast strains provide consistent and reliable fermentations, wines produced using single inocula are thought to lack the sensory complexity and rounded palate structure obtained from spontaneous fermentations. In contrast, interspecific yeast hybrids have the potential to deliver increased complexity to wine sensory properties and alternative wine styles through the formation of novel, and wider ranging, yeast volatile fermentation metabolite profiles, whilst maintaining the robustness of the wine yeast parent. Screening of newly generated hybrids from a cross between a S. cerevisiae wine yeast and S. mikatae (closely-related but ecologically distant members of the Saccharomyces sensu stricto clade), has identified progeny with robust fermentation properties and winemaking potential. Chemical analysis showed that, relative to the S. cerevisiae wine yeast parent, hybrids produced wines with different concentrations of volatile metabolites that are known to contribute to wine flavour and aroma, including flavour compounds associated with non-Saccharomyces species. The new S. cerevisiae x S. mikatae hybrids have the potential to produce complex wines akin to products of spontaneous fermentation while giving winemakers the safeguard of an inoculated ferment.

  15. Introducing a new breed of wine yeast: interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast and Saccharomyces mikatae.

    Directory of Open Access Journals (Sweden)

    Jennifer R Bellon

    Full Text Available Interspecific hybrids are commonplace in agriculture and horticulture; bread wheat and grapefruit are but two examples. The benefits derived from interspecific hybridisation include the potential of generating advantageous transgressive phenotypes. This paper describes the generation of a new breed of wine yeast by interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast strain and Saccharomyces mikatae, a species hitherto not associated with industrial fermentation environs. While commercially available wine yeast strains provide consistent and reliable fermentations, wines produced using single inocula are thought to lack the sensory complexity and rounded palate structure obtained from spontaneous fermentations. In contrast, interspecific yeast hybrids have the potential to deliver increased complexity to wine sensory properties and alternative wine styles through the formation of novel, and wider ranging, yeast volatile fermentation metabolite profiles, whilst maintaining the robustness of the wine yeast parent. Screening of newly generated hybrids from a cross between a S. cerevisiae wine yeast and S. mikatae (closely-related but ecologically distant members of the Saccharomyces sensu stricto clade, has identified progeny with robust fermentation properties and winemaking potential. Chemical analysis showed that, relative to the S. cerevisiae wine yeast parent, hybrids produced wines with different concentrations of volatile metabolites that are known to contribute to wine flavour and aroma, including flavour compounds associated with non-Saccharomyces species. The new S. cerevisiae x S. mikatae hybrids have the potential to produce complex wines akin to products of spontaneous fermentation while giving winemakers the safeguard of an inoculated ferment.

  16. Introducing a New Breed of Wine Yeast: Interspecific Hybridisation between a Commercial Saccharomyces cerevisiae Wine Yeast and Saccharomyces mikatae

    Science.gov (United States)

    Bellon, Jennifer R.; Schmid, Frank; Capone, Dimitra L.; Dunn, Barbara L.; Chambers, Paul J.

    2013-01-01

    Interspecific hybrids are commonplace in agriculture and horticulture; bread wheat and grapefruit are but two examples. The benefits derived from interspecific hybridisation include the potential of generating advantageous transgressive phenotypes. This paper describes the generation of a new breed of wine yeast by interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast strain and Saccharomyces mikatae, a species hitherto not associated with industrial fermentation environs. While commercially available wine yeast strains provide consistent and reliable fermentations, wines produced using single inocula are thought to lack the sensory complexity and rounded palate structure obtained from spontaneous fermentations. In contrast, interspecific yeast hybrids have the potential to deliver increased complexity to wine sensory properties and alternative wine styles through the formation of novel, and wider ranging, yeast volatile fermentation metabolite profiles, whilst maintaining the robustness of the wine yeast parent. Screening of newly generated hybrids from a cross between a S. cerevisiae wine yeast and S. mikatae (closely-related but ecologically distant members of the Saccharomyces sensu stricto clade), has identified progeny with robust fermentation properties and winemaking potential. Chemical analysis showed that, relative to the S. cerevisiae wine yeast parent, hybrids produced wines with different concentrations of volatile metabolites that are known to contribute to wine flavour and aroma, including flavour compounds associated with non-Saccharomyces species. The new S. cerevisiae x S. mikatae hybrids have the potential to produce complex wines akin to products of spontaneous fermentation while giving winemakers the safeguard of an inoculated ferment. PMID:23614011

  17. Barriers to Research Utilization among Registered Nurses in Traditional Chinese Medicine Hospitals: A Cross-Sectional Survey in China

    Directory of Open Access Journals (Sweden)

    Fen Zhou

    2015-01-01

    Full Text Available Background. As there might be relevant differences with regard to research utilization in the general hospitals, we aimed to study research utilization among registered nurses working in traditional Chinese medicine hospitals. Methods. A total of 648 registered nurses from 4 tertiary-level hospitals in China were recruited for participation. A modified BARRIERS Scale and self-designed questionnaires were used for data collection. Data were analyzed with descriptive statistics, t-tests, and one-way ANOVAs and Spearman correlation analysis. Results. Overall, items which belong to the subscale “Research” were identified as the most important barriers. Among the individual items, the lack of time on the job was ranked as the top barrier, followed by the lack of knowledgeable colleagues and by overwhelming research publications. Clinical experience, working pressure, job satisfaction, and research experience could be identified as associated factors for barriers to research utilization. Conclusions. Registered nurses in traditional Chinese medicine hospitals felt high barriers to research utilization. Reducing registered nurses’ working pressure, promoting their positive attitude to nursing, and improving research training might be helpful for increasing research utilization. Close cooperation between clinical and nursing schools or academic research centres might facilitate the necessary change in nursing education and routine.

  18. [Cross-cultural aspects of interaction and communication in mental health care. Barriers and recommendations for action].

    Science.gov (United States)

    Penka, S; Schouler-Ocak, M; Heinz, A; Kluge, U

    2012-09-01

    Mental health care for migrants is often impaired by a lack of policies and provisions in the respective institutions. This article focuses on "communication barriers" in psychosocial and psychotherapeutic settings, where personal communication is of great importance. Barriers that prevent migrants from using health care institutions include translation problems but also more complex misunderstandings based on divergent explanations regarding the causes, course, and adequate treatment of different disorders. The widely recommended intercultural opening of medical and psychosocial institutions involves using interpreters as cultural experts, reflecting on and mediating between divergent explanatory models, and avoiding cultural and ethnic stereotyping as well as encouraging an open, curious, and reflective professional attitude. With respect to institutional settings, rules for the financing of interpreters are as important as tackling barriers that limit migrants' access to medical and psychosocial institutions.

  19. Crossing the Telemedicine Chasm: Have the U.S. Barriers to Widespread Adoption of Telemedicine Been Significantly Reduced?

    Directory of Open Access Journals (Sweden)

    Cynthia LeRouge

    2013-11-01

    Full Text Available Barriers have challenged widespread telemedicine adoption by health care organizations for 40 years. These barriers have been technological, financial, and legal and have also involved business strategy and human resources. The article canvasses recent trends—events and activities in each of these areas as well as US health reform activities that might help to break down these barriers. The key to telemedicine success in the future is to view it as an integral part of health care services and not as a stand-alone project. Telemedicine must move from experimental and separate to integrated and equivalent to other health services within health care organizations. Furthermore, telemedicine serves as vital connective tissue for expanding health care organization networks.

  20. Crossing the Telemedicine Chasm: Have the U.S. Barriers to Widespread Adoption of Telemedicine Been Significantly Reduced? †

    Science.gov (United States)

    LeRouge, Cynthia; Garfield, Monica J.

    2013-01-01

    Barriers have challenged widespread telemedicine adoption by health care organizations for 40 years. These barriers have been technological, financial, and legal and have also involved business strategy and human resources. The article canvasses recent trends—events and activities in each of these areas as well as US health reform activities that might help to break down these barriers. The key to telemedicine success in the future is to view it as an integral part of health care services and not as a stand-alone project. Telemedicine must move from experimental and separate to integrated and equivalent to other health services within health care organizations. Furthermore, telemedicine serves as vital connective tissue for expanding health care organization networks. PMID:24287864

  1. Barriers in access to healthcare in countries with different health systems. A cross-sectional study in municipalities of central Colombia and north-eastern Brazil.

    Science.gov (United States)

    Garcia-Subirats, Irene; Vargas, Ingrid; Mogollón-Pérez, Amparo Susana; De Paepe, Pierre; da Silva, Maria Rejane Ferreira; Unger, Jean Pierre; Vázquez, María Luisa

    2014-04-01

    There are few comprehensive studies available on barriers encountered from the initial seeking of healthcare through to the resolution of the health problem; in other words, on access in its broad domain. For Colombia and Brazil, countries with different healthcare systems but common stated principles, there have been no such analyses to date. This paper compares factors that influence access in its broad domain in two municipalities of each country, by means of a cross-sectional study based on a survey of a multistage probability sample of people who had had at least one health problem within the last three months (2163 in Colombia and 2155 in Brazil). The results reveal important barriers to healthcare access in both samples, with notable differences between and within countries, once differences in sociodemographic characteristics and health needs are accounted for. In the Colombian study areas, the greatest barriers were encountered in initial access to healthcare and in resolving the problem, and similarly when entering the health service in the Brazilian study areas. Differences can also be detected in the use of services: in Colombia greater geographical and economic barriers and the need for authorization from insurers are more relevant, whereas in Brazil, it is the limited availability of health centres, doctors and drugs that leads to longer waiting times. There are also differences according to enrolment status and insurance scheme in Colombia, and between areas in Brazil. The barriers appear to be related to the Colombian system's segmented, non-universal nature, and to the involvement of insurance companies, and to chronic underfunding of the public system in Brazil. Further research is required, but the results obtained reveal critical points to be tackled by health policies in both countries. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Dasatinib crosses the blood-brain barrier and is an efficient therapy for central nervous system philadelphia chromosome positive leukemia

    NARCIS (Netherlands)

    K. Porkka (Kimmo); P. Koskenvesa (Perttu); T. Lundan (Tuija); J. Rimpiläinen (Johanna); S. Mustjoki (Satu); R. Smykla (Richard); R. Wild (Robert); R. Luo (Roger); M. Arnan (Montserrat); B. Brethon (Benoit); L. Eccersley (Lydia); H. Hjorth-Hansen (Henrik); M. Höglund (Martin); H. Klamova (Hana); H. Knutsen (Håvar); S. Parikh (Suhag); E. Raffoux (Emmanuel); F. Gruber (Franz); F. Brito-Babapulle (Finella); H. Dombret (Hervé); R.F. Duarte (Rafael); E. Elonen (Erkki); R. Paquette (Ron); C.M. Zwaan (Christian Michel); F.Y.F. Lee (Francis)

    2008-01-01

    textabstractAlthough imatinib, a BCR-ABL tyrosine kinase inhibitor, is used to treat acute Philadelphia chromosome-positive (Ph+) leukemia, it does not prevent central nervous system (CNS) relapses resulting from poor drug penetration through the blood-brain barrier. Imatinib and dasatinib (a

  3. Targeting metastatic breast cancer with ANG1005, a novel peptide-paclitaxel conjugate that crosses the blood-brain-barrier (BBB

    Directory of Open Access Journals (Sweden)

    Fei Li

    2017-03-01

    Full Text Available We devoted this short interview piece with Dr Shou-Ching Tang at Augusta University to feature some promising results from a clinical phase II trial on a novel brain-penetrating peptide-paclitaxel-conjugate, ANG1005, in treating brain metastatic breast cancer. These results were presented by Dr. Tang at the recent annual meeting of the European Society for Medical Oncology (ESMO 2016 Congress. This development heralds an important step forward towards the development of effective chemotherapeutic agents, which can cross the blood-brain-barrier and effectively treat and prevent the brain metastatic cancers.

  4. Barriers and Bridges to Positive Cross-Ethnic Relations: African American and White Parent Socialization Beliefs and Practices.

    Science.gov (United States)

    Hamm, Jill V.

    2001-01-01

    Using interviews and focus groups, lower and middle socioeconomic status (SES) African American parents and middle SES white parents discussed their objectives regarding cross-ethnic relations and how they helped their children forge positive cross-ethnic relations. The groups relied on different methods to promote socialization. Parents' efforts…

  5. Insulin initiation status of primary care physicians in Turkey, barriers to insulin initiation and knowledge levels about insulin therapy: A multicenter cross-sectional study.

    Science.gov (United States)

    Ates, Elif; Set, Turan; Saglam, Zuhal; Tekin, Nil; Karatas Eray, Irep; Yavuz, Erdinc; Sahin, Mustafa Kursat; Selcuk, Engin Burak; Cadirci, Dursun; Cubukcu, Mahcube

    2017-10-01

    Our aim was to evaluate the insulin initiation status, barriers to insulin initiation and knowledge levels about treatment administered by primary care physicians (PCP). We conducted our study in accordance with a multicenter, cross-sectional design in Turkey, between July 2015 and July 2016. A questionnaire inquiring demographic features, status of insulin initiation, obstacles to insulin initiation and knowledge about therapy of the PCPs was administered during face-to-face interviews. 84 PCPs (19%) (n=446, mean age=41.5±8.4years, 62.9% male and 90.0% ministry certified family physicians) initiated insulin therapy in the past. Most of the stated primary barriers (51.9%, n=230) were due to the physicians. The most relevant barrier was "lack of clinical experience" with a rate of 19% (n=84 of the total). The average total knowledge score was 5.7±2.0 for the family medicine specialist, and 3.8±2.1 for the ministry certified family physicians (p=0.000, maximum knowledge score could be 10). The status of insulin initiation in Turkey by the primary care physicians is inadequate. Medical education programs and health care systems may require restructuring to facilitate insulin initiation in primary care. Copyright © 2017 Primary Care Diabetes Europe. Published by Elsevier Ltd. All rights reserved.

  6. Experimental evolution of protozoan traits in response to interspecific competition.

    Science.gov (United States)

    terHorst, C P

    2011-01-01

    Decades of experiments have demonstrated the ecological effect of competition, but experimental evidence for competitive effects on trait evolution is rare. I measured the evolution of six protozoan traits in response to competitors from the inquiline community of pitcher plants. Replicate populations of Colpoda, a ciliated protozoan, were allowed to evolve in response to intra- and interspecific competition for 20 days (approximately 100 generations), before traits were measured in two common garden environments. Populations that evolved with interspecific competition had smaller cell sizes, produced fewer cysts and had higher population growth rates relative to populations grown in monoculture. The presence of interspecific competitors led to differential lineage sorting, most likely by increasing the strength of selection. These results are the first to demonstrate protozoan evolution in response to competition and may have implications for species coexistence in this system. © 2010 The Author. Journal of Evolutionary Biology © 2010 European Society For Evolutionary Biology.

  7. Stages of change, barriers, benefits, and preferences for exercise in RA patients: a cross-sectional study.

    Science.gov (United States)

    Henchoz, Y; Zufferey, P; So, A

    2013-01-01

    To determine the distribution of exercise stages of change in a rheumatoid arthritis (RA) cohort, and to examine patients' perceptions of exercise benefits, barriers, and their preferences for exercise. One hundred and twenty RA patients who attended the Rheumatology Unit of a University Hospital were asked to participate in the study. Those who agreed were administered a questionnaire to determine their exercise stage of change, their perceived benefits and barriers to exercise, and their preferences for various features of exercise. Eighty-nine (74%) patients were finally included in the analyses. Their mean age was 58.4 years, mean RA duration 10.1 years, and mean disease activity score 2.8. The distribution of exercise stages of change was as follows: precontemplation (n = 30, 34%), contemplation (n = 11, 13%), preparation (n = 5, 6%), action (n = 2, 2%), and maintenance (n = 39, 45%). Compared to patients in the maintenance stage of change, precontemplators exhibited different demographic and functional characteristics and reported less exercise benefits and more barriers to exercise. Most participants preferred exercising alone (40%), at home (29%), at a moderate intensity (64%), with advice provided by a rheumatologist (34%) or a specialist in exercise and RA (34%). Walking was by far the preferred type of exercise, in both the summer (86%) and the winter (51%). Our cohort of patients with RA was essentially distributed across the precontemplation and maintenance exercise stages of change. These subgroups of patients exhibit psychological and functional differences that make their needs different in terms of exercise counselling.

  8. DEVELOPMENT AND COMPREHENSIVE ASSESSMENT OF BULBOUS FORMS OF INTERSPECIFIC HYBRIDS OF ONION ALLIUM CEPA x A. FISTULOSUM

    Directory of Open Access Journals (Sweden)

    V. S. Romanov

    2016-01-01

    Full Text Available One of the way of increasing of genetic variability of onion (Allium cepa L. is the interspecific hybridization. Development of onion interspecific hybrids consists of the study of initial breeding forms, its heterogeneity, ways of crossing and pollination, overcoming of outbreeding problem, sterility and weak fertility of the hybrids of first and next generations, specifics of hybrid’s seeds development, identification and selection of recombinant forms with breeding valuable traits. The stages of development of the bulbous forms of interspecific hybrids of onion are presented in the article. The study was conducted in the “All-Russian Scientific Research Institute of vegetable breeding and seed production” of the Moscow region. The plants of inbreed progenies I1-5 from BC1-2F5 of bulb forms of interspecific hybrids A. cepa х A. Fistulosum as well as the parental forms were analyzed. The breeding and phytopathological assessment of recombinant forms of onion interspecific hybrids was done for qualitative and quantitative traits and for resistance to downy mildew. Using the individual selection for quality and quantity traits, it was found that the forms, whose traits were not undergo the inbreeding depression because of the higher homozygosity can be used for development of linear initial material for breeding for heterosis. The forms with the inbreeding depression have to be used for crossbreeding. Along with increasing of homozygosity, the new modified genotypes appear because of potential variability and genes recombination. It allows to make the purposive selection of recombinant forms for valuable traits. The selected onion forms from inbreed progenies of I1-5 from BC1-2F5 which have bulbs of flat and well-rounded-flat shape are characterized by high resistance to downy mildew and bulbs with good storage ability. The selection process of the recombinant forms from progenies of onion interspecific hybrids obtained based on repeated

  9. Peptide gH625 enters into neuron and astrocyte cell lines and crosses the blood–brain barrier in rats

    Directory of Open Access Journals (Sweden)

    Valiante S

    2015-03-01

    Full Text Available Salvatore Valiante,1,* Annarita Falanga,2,3,* Luisa Cigliano,1 Giuseppina Iachetta,1 Rosa Anna Busiello,1 Valeria La Marca,1 Massimiliano Galdiero,4 Assunta Lombardi,1 Stefania Galdiero1,2 1Department of Biology, 2Department of Pharmacy, 3DFM Scarl, University of Naples Federico II, 4Department of Experimental Medicine, II University of Naples, Naples, Italy *These authors contributed equally to this paper and are considered joint first authors Abstract: Peptide gH625, derived from glycoprotein H of herpes simplex virus type 1, can enter cells efficiently and deliver a cargo. Nanoparticles armed with gH625 are able to cross an in vitro model of the blood–brain barrier (BBB. In the present study, in vitro experiments were performed to investigate whether gH625 can enter and accumulate in neuron and astrocyte cell lines. The ability of gH625 to cross the BBB in vivo was also evaluated. gH625 was administered in vivo to rats and its presence in the liver and in the brain was detected. Within 3.5 hours of intravenous administration, gH625 can be found beyond the BBB in proximity to cell neurites. gH625 has no toxic effects in vivo, since it does not affect the maximal oxidative capacity of the brain or the mitochondrial respiration rate. Our data suggest that gH625, with its ability to cross the BBB, represents a novel nanocarrier system for drug delivery to the central nervous system. These results open up new possibilities for direct delivery of drugs into patients in the field of theranostics and might address the treatment of several human diseases. Keywords: drug delivery, neurons, astrocytes, blood–brain barrier, peptide

  10. Identifying motivators and barriers to older community-dwelling people participating in resistance training: A cross-sectional study.

    Science.gov (United States)

    Burton, Elissa; Lewin, Gill; Pettigrew, Simone; Hill, Anne-Marie; Bainbridge, Liz; Farrier, Kaela; Langdon, Trish; Airey, Phil; Hill, Keith D

    2017-08-01

    Participation rates of older people in resistance training (RT) are low despite increasing research showing many health benefits. To increase the number of older people participating in RT it is important to know what would motivate people to become involved, what motivates those who participate to continue, and the factors preventing many older people from commencing participation. To investigate these issues, a questionnaire was mailed to three groups of older people: (1) those receiving home care services, (2) members of a peak non-government seniors' organisation and (3) those participating in a specific gym-based RT programme. In total, 1327 questionnaires were returned (response rate = 42.5%). To feel good physically and mentally were the main reasons motivating participation among all three groups, and falls prevention was identified as an important motivator for the home care respondents. Pain, injury and illness were the main barriers to participating, or continuing to participate. However, medical advice was a factor influencing participation commencement. The results suggest organisations providing RT programmes for older people should tailor the promotion and delivery of programmes to address key motivators and barriers specific to each group to increase the proportion of older people initiating and continuing to engage in RT.

  11. Gamma irradiation of the interspecific hybrids Gossypium hirsutum L. x G. barbadense L. Part 1

    International Nuclear Information System (INIS)

    Stoilova, A.

    1990-01-01

    The aim of the investigation is to combine the methods of hybridization and experimental mutagenesis and to widen the possibilities of interspecific hybridization for successful breeding work. Four hybrid combinations resulting from reciprocal crosses between the two species were studied. Seeds of long fibre F 1 plants from each combination were devided in four equal parts, three of which were irradiated with doses 15, 20 and 25 krad and one remained as control. The complex radiosensitivity evaluation of the four hybrid combinations investigated was based on the changes in the main biometrical indices comparing the control with 25 krad treatment and showed that the F 2 hybrids were either resistant or slightly sensitive to irradiation depending on the direction of crossing in respect to growth process, field germination and survival to the end of vegetation. 2 figs., 3 tabs., 14 refs

  12. Glass Barriers : Constraints to Women's Small-Scale Cross-Border Trade in Cambodia and Lao PDR

    OpenAIRE

    Seror, Marlon; Record, Richard; Clarke, Julian

    2017-01-01

    Trade facilitation projects often assume indirect benefits for small-scale, cross-border traders. Recent studies have shown the challenges faced in Africa by this population, especially women, but it remains unknown in Cambodia and the Lao People's Democratic Republic, despite large trade facilitation investments. This paper fills this gap, thanks to an innovative mix of original qualitati...

  13. Genetic Identification of Hyalodaphnia Species and Interspecific Hybrids

    NARCIS (Netherlands)

    Billiones, R.; Brehm, G.M.; Klee, J.; Schwenk, K.

    2004-01-01

    Species of the genus Daphnia, in particular the subgenus Hyalodaphnia, represent a taxonomically problematic group due to their phenotypic plasticity, local races and the formation of interspecific hybrids and backcrosses. In this study, we present a genetic approach utilising nuclear DNA to

  14. Sex-specific asymmetry in eye development in interspecific hybrids ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics; Volume 94; Issue 3. Sex-specific asymmetry in eye development in interspecific hybrids in the Drosophila bipectinata species complex. Bashisth N. Singh Parul Banerjee. Research Note Volume 94 Issue 3 September 2015 pp 493-495 ...

  15. Quantitative trait loci mapping for stomatal traits in interspecific ...

    Indian Academy of Sciences (India)

    Dr.YASODHA

    seedling raising, field planting and maintenance of the mapping population. ... tereticornis and production of interspecific hybrids displaying hybrid vigour in terms of .... A total of 114, 115 and 129 SSR, ISSR and SRAP markers were generated .... stomatal traits with yield and adaptability would help to improve productivity of ...

  16. Evaluation of interspecific DNA variability in poplars using AFLP and ...

    African Journals Online (AJOL)

    The objective of this paper was to examine interspecific DNA variation in poplars using AFLP and SSR markers. The AFLP and SSR markers polymorphism and its power of discrimination were determined within 13 genotypes of different genetic background (clones, cultivars, hybrids) of two sections (Aigeiros and ...

  17. Interspecific and interploidal gene flow in Central European Arabidopsis (Brassicaceae

    Directory of Open Access Journals (Sweden)

    Jørgensen Marte H

    2011-11-01

    Full Text Available Abstract Background Effects of polyploidisation on gene flow between natural populations are little known. Central European diploid and tetraploid populations of Arabidopsis arenosa and A. lyrata are here used to study interspecific and interploidal gene flow, using a combination of nuclear and plastid markers. Results Ploidal levels were confirmed by flow cytometry. Network analyses clearly separated diploids according to species. Tetraploids and diploids were highly intermingled within species, and some tetraploids intermingled with the other species, as well. Isolation with migration analyses suggested interspecific introgression from tetraploid A. arenosa to tetraploid A. lyrata and vice versa, and some interploidal gene flow, which was unidirectional from diploid to tetraploid in A. arenosa and bidirectional in A. lyrata. Conclusions Interspecific genetic isolation at diploid level combined with introgression at tetraploid level indicates that polyploidy may buffer against negative consequences of interspecific hybridisation. The role of introgression in polyploid systems may, however, differ between plant species, and even within the small genus Arabidopsis, we find very different evolutionary fates when it comes to introgression.

  18. Construction of an EST-SSR-based interspecific transcriptome ...

    Indian Academy of Sciences (India)

    Construction of an EST-SSR-based interspecific transcriptome linkage map of fibre development in cotton. CHUANXIANG LIU, DAOJUN YUAN and ZHONGXU LIN. ∗. National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research (Wuhan),. Huazhong Agricultural University, Wuhan ...

  19. Motivators and barriers to mammography screening uptake by female health-care workers in primary health-care centres: a cross-sectional study.

    Science.gov (United States)

    Nazzal, Zaher; Sholi, Hisham; Sholi, Suha B; Sholi, Mohammad B; Lahaseh, Rawya

    2018-02-21

    Mammography screening is an effective tool for early detection and management of breast cancer. Female health-care workers' awareness of breast cancer screening is important because their beliefs and behaviours could influence other women. The aim of this study was to assess mammography screening uptake by female health-care workers at primary health-care centres and to identify the primary motivators and barriers that affect uptake. This cross-sectional study included all governmental primary health-care centres in the West Bank. Governorates were grouped into three regions as follows: north West Bank (Nablus, Jenin, Tulkarm, Tubas, Qalqiliya, and Salfit), middle West Bank (Jerusalem, Jericho, and Ramallah), and south West Bank (Hebron, and Bethlehem). The study population included all female health-care workers older than 40 years. Those who performed mammography for a suspected mass or other breast abnormalities were excluded. A self-administered questionnaire was used to collect data on demographic characteristics, knowledge about mammography screening, the extent and regularity of mammography screening, and motivators and barriers influencing their mammography screening uptake. The rate of mammography screening uptake was calculated. χ 2 test and t tests were used to assess screening motivators and barriers. The study was approved by the Institutional Review Board of the An-Najah National University. Participation was voluntary, and written consent was obtained from each participant. 299 female health-care workers completed a self-administered questionnaire. The mean age of the participants was 46 years (SD 4·7). 284 (95%) women had adequate knowledge about breast cancer and mammography screening, and 149 (50%) women reported having had at least one mammogram. 62 (21%) women had had regular scheduled mammograms. The most frequent reported motivators were the perceived benefit that early detection of breast cancer is important for its management (269 [90

  20. Cross-sector surveys assessing perceptions of key stakeholders towards barriers, concerns and facilitators to the appropriate use of adaptive designs in confirmatory trials.

    Science.gov (United States)

    Dimairo, Munyaradzi; Julious, Steven A; Todd, Susan; Nicholl, Jonathan P; Boote, Jonathan

    2015-12-23

    Appropriately conducted adaptive designs (ADs) offer many potential advantages over conventional trials. They make better use of accruing data, potentially saving time, trial participants, and limited resources compared to conventional, fixed sample size designs. However, one can argue that ADs are not implemented as often as they should be, particularly in publicly funded confirmatory trials. This study explored barriers, concerns, and potential facilitators to the appropriate use of ADs in confirmatory trials among key stakeholders. We conducted three cross-sectional, online parallel surveys between November 2014 and January 2015. The surveys were based upon findings drawn from in-depth interviews of key research stakeholders, predominantly in the UK, and targeted Clinical Trials Units (CTUs), public funders, and private sector organisations. Response rates were as follows: 30(55 %) UK CTUs, 17(68 %) private sector, and 86(41 %) public funders. A Rating Scale Model was used to rank barriers and concerns in order of perceived importance for prioritisation. Top-ranked barriers included the lack of bridge funding accessible to UK CTUs to support the design of ADs, limited practical implementation knowledge, preference for traditional mainstream designs, difficulties in marketing ADs to key stakeholders, time constraints to support ADs relative to competing priorities, lack of applied training, and insufficient access to case studies of undertaken ADs to facilitate practical learning and successful implementation. Associated practical complexities and inadequate data management infrastructure to support ADs were reported as more pronounced in the private sector. For funders of public research, the inadequate description of the rationale, scope, and decision-making criteria to guide the planned AD in grant proposals by researchers were all viewed as major obstacles. There are still persistent and important perceptions of individual and organisational obstacles

  1. Genetic Linkage Map Construction and QTL Analysis of Two Interspecific Reproductive Isolation Traits in Sponge Gourd.

    Science.gov (United States)

    Wu, Haibin; He, Xiaoli; Gong, Hao; Luo, Shaobo; Li, Mingzhu; Chen, Junqiu; Zhang, Changyuan; Yu, Ting; Huang, Wangping; Luo, Jianning

    2016-01-01

    The hybrids between Luffa acutangula (L.) Roxb. and L.cylindrica (L.) Roem. have strong heterosis effects. However, some reproductive isolation traits hindered their normal hybridization and fructification, which was mainly caused by the flowering time and hybrid pollen sterility. In order to study the genetic basis of two interspecific reproductive isolation traits, we constructed a genetic linkage map using an F2 population derived from a cross between S1174 [L. acutangula (L.) Roxb.] and 93075 [L. cylindrica (L.) Roem.]. The map spans 1436.12 CentiMorgans (cM), with an average of 8.11 cM among markers, and consists of 177 EST-SSR markers distributed in 14 linkage groups (LG) with an average of 102.58 cM per LG. Meanwhile, we conducted colinearity analysis between the sequences of EST-SSR markers and the genomic sequences of cucumber, melon and watermelon. On the basis of genetic linkage map, we conducted QTL mapping of two reproductive isolation traits in sponge gourd, which were the flowering time and hybrid male sterility. Two putative QTLs associated with flowering time (FT) were both detected on LG 1. The accumulated contribution of these two QTLs explained 38.07% of the total phenotypic variance (PV), and each QTL explained 15.36 and 22.71% of the PV respectively. Four QTLs for pollen fertility (PF) were identified on LG 1 (qPF1.1 and qPF1.2), LG 3 (qPF3) and LG 7 (qPF7), respectively. The percentage of PF explained by these QTLs varied from 2.91 to 16.79%, and all together the four QTLs accounted for 39.98% of the total PV. Our newly developed EST-SSR markers and linkage map are very useful for gene mapping, comparative genomics and molecular marker-assisted breeding. These QTLs for interspecific reproductive isolation will also contribute to the cloning of genes relating to interspecific reproductive isolation and the utilization of interspecific heterosis in sponge gourd in further studies.

  2. Age of Barrier Canyon-style rock art constrained by cross-cutting relations and luminescence dating techniques

    DEFF Research Database (Denmark)

    Pederson, Joel L.; Chapot, Melissa S.; Simms, Steven R.

    2014-01-01

    Rock art compels interest from both researchers and a broader public, inspiring many hypotheses about its cultural origin and meaning, but it is notoriously difficult to date numerically. Barrier Canyon-style (BCS) pictographs of the Colorado Plateau are among the most debated examples; hypotheses......, the type section of BCS art in Canyon-lands National Park, southeastern Utah. Alluvial chronostratigraphy constrains the burial and exhumation of the alcove containing the panel, and limits are also set by our related research dating both a rockfall that removed some figures and the rock's exposure...... duration before that time. Results provide a maximum possible age, a minimum age, and an exposure time window for the creation of the Great Gallery panel, respectively. The only prior hypothesis not disproven is a late Archaic origin for BCS rock art, although our age result of A. D. similar to 1...

  3. Recent advancements in liposomes targeting strategies to cross blood-brain barrier (BBB) for the treatment of Alzheimer's disease.

    Science.gov (United States)

    Agrawal, Mukta; Ajazuddin; Tripathi, Dulal K; Saraf, Swarnlata; Saraf, Shailendra; Antimisiaris, Sophia G; Mourtas, Spyridon; Hammarlund-Udenaes, Margareta; Alexander, Amit

    2017-08-28

    In this modern era, with the help of various advanced technologies, medical science has overcome most of the health-related issues successfully. Though, some diseases still remain unresolved due to various physiological barriers. One such condition is Alzheimer; a neurodegenerative disorder characterized by progressive memory impairment, behavioral abnormalities, mood swing and disturbed routine activities of the person suffering from. It is well known to all that the brain is entirely covered by a protective layer commonly known as blood brain barrier (BBB) which is responsible to maintain the homeostasis of brain by restricting the entry of toxic substances, drug molecules, various proteins and peptides, small hydrophilic molecules, large lipophilic substances and so many other peripheral components to protect the brain from any harmful stimuli. This functionally essential structure creates a major hurdle for delivery of any drug into the brain. Still, there are some provisions on BBB which facilitate the entry of useful substances in the brain via specific mechanisms like passive diffusion, receptor-mediated transcytosis, carrier-mediated transcytosis etc. Another important factor for drug transport is the selection of a suitable drug delivery systems like, liposome, which is a novel drug carrier system offering a potential approach to resolving this problem. Its unique phospholipid bilayer structure (similar to physiological membrane) had made it more compatible with the lipoidal layer of BBB and helps the drug to enter the brain. The present review work focused on various surface modifications with functional ligand (like lactoferrin, transferrin etc.) and carrier molecules (such as glutathione, glucose etc.) on the liposomal structure to enhance its brain targeting ability towards the successful treatment of Alzheimer disease. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Home Care Pharmacy Practice in Canada: A Cross-Sectional Survey of Services Provided, Remuneration, Barriers, and Facilitators.

    Science.gov (United States)

    Houle, Sherilyn; MacKeigan, Linda

    2017-01-01

    As the population ages, and individuals desire to remain in their homes as long as possible, the need for in-home care is expected to increase. However, pharmacists have rarely been included in studies of in-home care, and little is known about the prevalence or effectiveness of pharmacists' home-based services in Canada. To identify pharmacy practices in Canada that regularly provide in-home patient care and to identify specific services provided, remuneration obtained, and barriers and facilitators influencing the provision of home-based care. A link to a web-based survey was posted in e-newsletters of provincial, territorial, and national pharmacy associations in Canada. In addition, pharmacists known to the researchers as providing in-home clinical services were contacted directly. The survey was open from October to December 2015. Practices or organizations that performed at least one home visit per week for clinical purposes, with documentation of the services provided, were eligible to participate. One response per practice or organization was allowed. Seventeen practices meeting the inclusion criteria were identified, representing community, hospital, and clinic settings. Home visits were most commonly performed for individuals with complex medication regimens or nonadherence to medication therapy. The most common services were conducting medication reconciliation and reviews and counselling patients about medication adherence. No practices or organizations billed patients for these services, yet lack of remuneration was an important barrier identified by many respondents. Although 12 (71%) of the respondents collected data for evaluative purposes, collection of clinical or health system outcome data was rare. Few Canadian pharmacy practices that provide in-home patient care at least once a week could be identified. Data collection suitable to establish an evidence base for this service was infrequently performed by practices and organizations providing

  5. Sexual imprinting misguides species recognition in a facultative interspecific brood parasite.

    Science.gov (United States)

    Sorenson, Michael D; Hauber, Mark E; Derrickson, Scott R

    2010-10-22

    Sexual reproduction relies on the recognition of conspecifics for breeding. Most experiments in birds have implicated a critical role for early social learning in directing subsequent courtship behaviours and mating decisions. This classical view of avian sexual imprinting is challenged, however, by studies of megapodes and obligate brood parasites, species in which reliable recognition is achieved despite the lack of early experience with conspecifics. By rearing males with either conspecific or heterospecific brood mates, we experimentally tested the effect of early social experience on the association preferences and courtship behaviours of two sympatrically breeding ducks. We predicted that redheads (Aythya americana), which are facultative interspecific brood parasites, would show a diminished effect of early social environment on subsequent courtship preferences when compared with their host and congener, the canvasback (Aythya valisineria). Contrary to expectations, cross-fostered males of both species courted heterospecific females and preferred them in spatial association tests, whereas control males courted and associated with conspecific females. These results imply that ontogenetic constraints on species recognition may be a general impediment to the initial evolution of interspecific brood parasitism in birds. Under more natural conditions, a variety of mechanisms may mitigate or counteract the effects of early imprinting for redheads reared in canvasback broods.

  6. The cytology, isozyme, HPLC fingerprint, and interspecific hybridization studies of genus epimedium (berberidaceae).

    Science.gov (United States)

    Wang, Lin-Jiao; Sheng, Mao-Yin

    2013-01-01

    104 samples from 27 accessions belonging to 12 species of genus Epimedium were studied on the basis of cytology observation, POD (i.e., peroxide) isozyme, high performance liquid chromatography (i.e., HPLC) fingerprint, and interspecific hybridization. The cytology observation showed karyotypes of twelve species studied; all are 2A symmetry type of Stebbins standard and similar to each other, and except for karyotype of E. leptorrhizum which is 2n = 2x = 8m (2SAT) + 4sm, the rest are 2n = 2x = 6m (2SAT) + 6sm. Chromosomes C-banding of barrenwort species varies, with 15 to 22 bands, consisting of centromeric bands, intercalary bands, terminal bands, and middle satellite bands. Results of POD isozyme showed that the zymographs vary greatly and sixteen bands were detected in the eleven species, and each species has its own characteristic bands different from the others. Studies on the HPLC fingerprint showed that the HPLC fingerprint of different species has characteristic peaks, divided into two regions (retention time 10 min). Results of interspecific hybridization showed that crosses of any combination among seven species studied are successful and the rates of grain set vary greatly. Based on these results, the system and phylogeny of this genus were inferred.

  7. Barriers to treatment and control of hypertension among hypertensive participants: A community based cross-sectional mixed method study in municipalities of Kathmandu, Nepal

    Directory of Open Access Journals (Sweden)

    Surya Devkota

    2016-08-01

    Full Text Available AbstractIntroduction: Despite the established evidence on benefits of controlling raised blood pressure and development of several guidelines on detection and management of hypertension, people often have untreated or uncontrolled hypertension. In this context, we undertook this study to identify the barriers existing in hypertension treatment and control in the municipalities of Kathmandu district in Nepal. Methods: This was a community based, cross-sectional mixed method study conducted in the municipalities of Kathmandu district in Nepal between January and July 2015. Among 587 randomly selected participants, the aware hypertensive participants were further assessed for the treatment and control of hypertension. For qualitative component, 20 participants having uncontrolled hypertension took part in two focused group discussions and two cardiac physicians participated in in-depth interviews.Results: Out of 587 participants screened, 191 (32.5% were identified as hypertensive. Among 191 hypertensive participants, 118 (61.8% were aware of their problem. Of the 118 aware hypertensive participants, 93 (78.8% were taking medicines, and among those treated, 46 (49.6% had controlled hypertension. Proportions of participants taking anti-hypertensive medications varied significantly with age groups, ethnicity, occupation and income. Hypertension control was significantly associated with use of combination therapy, adherence to medication, follow-up care, counseling by healthcare providers and waiting time in hospital. Being worried that the medicine needs to be taken life-long, perceived side effects of drugs, non-adherence to medication, lost to follow-up, inadequate counseling from physician, and lack of national guidelines for hypertension treatment were the most commonly cited barriers for treatment and control of hypertension in qualitative component of the research.Conclusion: Large proportion of the hypertensive population has the untreated and

  8. Dopamine D2-receptor imaging with [sup 123]I-iodobenzamide SPECT in migraine patients abusing ergotamine: does ergotamine cross the blood brain barrier

    Energy Technology Data Exchange (ETDEWEB)

    Verhoeff, N.P.; Visser, W.H.; Ferrari, M.D.; Saxena, P.R.; Royen, E.A. van (Erasmus Univ., Rotterdam (Netherlands))

    1993-10-01

    Two migraine patients were studied by in vivo SPECT using the dopamine D2-receptor specific radioligand [sup 123]I-3-iodo-6-methoxybenzamide ([sup 123]I-IBZM) during ergotamine abuse and after withdrawal. Results were compared with 15 healthy controls. Striatum/cerebellum and striatum/occipital cortex ratios of count rate density were calculated as a semiquantitative measurement for striatal dopamine D2-receptor binding potential. No differences were found in striatal uptake of [sup 123]I-IBZM between healthy controls and the patients when on or off ergotamine. Preliminary evidence suggests that ergotamine may not occupy striatal dopamine D2-receptors to a large extent and thus may not cross the blood brain barrier in large quantities. 23 refs., 3 figs.

  9. Barriers to healthy eating by National Health Service (NHS hospital doctors in the hospital setting: results of a cross-sectional survey

    Directory of Open Access Journals (Sweden)

    Wilson Sue

    2008-08-01

    Full Text Available Abstract Background With high levels of obesity and related illness, improving the health of the nation is a major public health concern. This study aimed to identify factors that prevent healthy eating among doctors, and that are associated with satisfaction with catering services. Findings Methods: Cross-sectional survey of 328 NHS doctors working in two NHS Trusts with on-site hospital canteen. Questionnaire to establish perceived barriers to healthy eating, weekly use and satisfaction with the hospital canteen, lifestyle and dietary habits, gender, age, height, weight, job details, and affect. Results: 70% of doctors reported using their hospital canteen each week, with 2 visits per week on average. Canteen opening times, lack of selection and lack of breaks were the most commonly perceived barriers to healthy eating. Availability of healthy options caused the most dissatisfaction. Only 12% felt the NHS was supportive of healthy eating. 74% did not feel their canteen advocated healthy eating. Canteen use is associated with younger age (r = -0.254, p Conclusion Interventions to encourage regular meal breaks, eating breakfast and drinking more water each day need developing. Improved canteen accessibility and availability of healthy options at evenings and weekends may be beneficial.

  10. Human serum albumin nanoparticles modified with apolipoprotein A-I cross the blood-brain barrier and enter the rodent brain.

    Science.gov (United States)

    Zensi, Anja; Begley, David; Pontikis, Charles; Legros, Celine; Mihoreanu, Larisa; Büchel, Claudia; Kreuter, Jörg

    2010-12-01

    Nanoparticles made of human serum albumin (HSA) and modified with apolipoproteins have previously been shown to transport drugs, which normally do not enter the brain, across the blood-brain barrier (BBB). However the precise mechanism by which nanoparticles with different apolipoproteins on their surface can target to the brain, as yet, has not been totally elucidated. In the present study, HSA nanoparticles with covalently bound apolipoprotein A-I (Apo A-I) as a targetor for brain capillary endothelial cells were injected intravenously into SV 129 mice and Wistar rats. The rodents were sacrificed after 15 or 30 min, and their brains were examined by transmission electron microscopy. Apo A-I nanoparticles could be found inside the endothelial cells of brain capillaries as well as within parenchymal brain tissue of both, mice and rats, whereas control particles without Apo A-I on their surface did not cross the BBB during our experiments. The maintenance of tight junction integrity and barrier function during treatment with nanoparticles was demonstrated by perfusion with a fixative containing lanthanum nitrate as an electron dense marker for the permeability of tight junctions.

  11. Comparison between cross sections, saddle point and scission point barriers for the 32S+24Mg reaction

    Directory of Open Access Journals (Sweden)

    Santos T. J.

    2014-04-01

    Full Text Available One of the principal characteristics of nuclear multifragmentation is the emission of complex fragments of intermediate mass. The statistical multifragmentation model has been used for many years to describe the distribution of these fragments. An extension of the statistical multifragmentation model to include partial widths and lifetimes for emission, interprets the fragmentation process as the near simultaneous limit of a series of sequential binary decays. In this extension, the expression describing intermediate mass fragment emission is almost identical to that of light particle emission. At lower temperatures, similar expressions have been shown to furnish a good description of very light intermediate mass fragment emission. However, this is usually not considered a good approximation to the emission of heavier fragments. These emissions seem to be determined by the characteristics of the system at the saddle-point and its subsequent dynamical evolution rather than by the scission point. Here, we compare the barriers and decay widths of these different formulations of intermediate fragment emission and analyze the extent to which they remain distinguishable at high excitation energy.

  12. Comparison between cross sections, saddle point and scission point barriers for the {sup 32}S+{sup 24}Mg reaction

    Energy Technology Data Exchange (ETDEWEB)

    Santos, T.J.; Carlson, B.V., E-mail: nztiago@gmail.com [Instituto Tecnologia de Aeronautica (ITA), Sao Jose dos Campos, SP (Brazil)

    2014-07-01

    One of the principal characteristics of nuclear multifragmentation is the emission of complex fragments of intermediate mass. The statistical multifragmentation model has been used for many years to describe the distribution of these fragments. An extension of the statistical multifragmentation model to include partial widths and lifetimes for emission, interprets the fragmentation process as the near simultaneous limit of a series of sequential binary decays. In this extension, the expression describing intermediate mass fragment emission is almost identical to that of light particle emission. At lower temperatures, similar expressions have been shown to furnish a good description of very light intermediate mass fragment emission. However, this is usually not considered a good approximation to the emission of heavier fragments. These emissions seem to be determined by the characteristics of the system at the saddle-point and its subsequent dynamical evolution rather than by the scission point. Here, we compare the barriers and decay widths of these different formulations of intermediate fragment emission and analyze the extent to which they remain distinguishable at high excitation energy. (author)

  13. On the phantom barrier crossing and the bounds on the speed of sound in non-minimal derivative coupling theories

    Science.gov (United States)

    Quiros, Israel; Gonzalez, Tame; Nucamendi, Ulises; García-Salcedo, Ricardo; Horta-Rangel, Francisco Antonio; Saavedra, Joel

    2018-04-01

    In this paper we investigate the so-called ‘phantom barrier crossing’ issue in a cosmological model based on the scalar–tensor theory with non-minimal derivative coupling to the Einstein tensor. Special attention will be paid to the physical bounds on the squared sound speed. The numeric results are geometrically illustrated by means of a qualitative procedure of analysis that is based on the mapping of the orbits in the phase plane onto the surfaces that represent physical quantities in the extended phase space, that is: the phase plane complemented with an additional dimension relative to the given physical parameter. We find that the cosmological model based on the non-minimal derivative coupling theory—this includes both the quintessence and the pure derivative coupling cases—has serious causality problems related to superluminal propagation of the scalar and tensor perturbations. Even more disturbing is the finding that, despite the fact that the underlying theory is free of the Ostrogradsky instability, the corresponding cosmological model is plagued by the Laplacian (classical) instability related with negative squared sound speed. This instability leads to an uncontrollable growth of the energy density of the perturbations that is inversely proportional to their wavelength. We show that, independent of the self-interaction potential, for positive coupling the tensor perturbations propagate superluminally, while for negative coupling a Laplacian instability arises. This latter instability invalidates the possibility for the model to describe the primordial inflation.

  14. The mitochondrial genome impacts respiration but not fermentation in interspecific Saccharomyces hybrids.

    Directory of Open Access Journals (Sweden)

    Warren Albertin

    Full Text Available In eukaryotes, mitochondrial DNA (mtDNA has high rate of nucleotide substitution leading to different mitochondrial haplotypes called mitotypes. However, the impact of mitochondrial genetic variant on phenotypic variation has been poorly considered in microorganisms because mtDNA encodes very few genes compared to nuclear DNA, and also because mitochondrial inheritance is not uniparental. Here we propose original material to unravel mitotype impact on phenotype: we produced interspecific hybrids between S. cerevisiae and S. uvarum species, using fully homozygous diploid parental strains. For two different interspecific crosses involving different parental strains, we recovered 10 independent hybrids per cross, and allowed mtDNA fixation after around 80 generations. We developed PCR-based markers for the rapid discrimination of S. cerevisiae and S. uvarum mitochondrial DNA. For both crosses, we were able to isolate fully isogenic hybrids at the nuclear level, yet possessing either S. cerevisiae mtDNA (Sc-mtDNA or S. uvarum mtDNA (Su-mtDNA. Under fermentative conditions, the mitotype has no phenotypic impact on fermentation kinetics and products, which was expected since mtDNA are not necessary for fermentative metabolism. Alternatively, under respiratory conditions, hybrids with Sc-mtDNA have higher population growth performance, associated with higher respiratory rate. Indeed, far from the hypothesis that mtDNA variation is neutral, our work shows that mitochondrial polymorphism can have a strong impact on fitness components and hence on the evolutionary fate of the yeast populations. We hypothesize that under fermentative conditions, hybrids may fix stochastically one or the other mt-DNA, while respiratory environments may increase the probability to fix Sc-mtDNA.

  15. Barriers to initiation of antiretroviral treatment in rural and urban areas of Zambia: a cross-sectional study of cost, stigma, and perceptions about ART.

    Science.gov (United States)

    Fox, Matthew P; Mazimba, Arthur; Seidenberg, Phil; Crooks, Denise; Sikateyo, Bornwell; Rosen, Sydney

    2010-03-06

    While the number of HIV-positive patients on antiretroviral therapy (ART) in resource-limited settings has increased dramatically, some patients eligible for treatment do not initiate ART even when it is available to them. Understanding why patients opt out of care, or are unable to opt in, is important to achieving the goal of universal access. We conducted a cross-sectional survey among 400 patients on ART (those who were able to access care) and 400 patients accessing home-based care (HBC), but who had not initiated ART (either they were not able to, or chose not to, access care) in two rural and two urban sites in Zambia to identify barriers to and facilitators of ART uptake. HBC patients were 50% more likely to report that it would be very difficult to get to the ART clinic than those on ART (RR: 1.48; 95% CI: 1.21-1.82). Stigma was common in all areas, with 54% of HBC patients, but only 15% of ART patients, being afraid to go to the clinic (RR: 3.61; 95% CI: 3.12-4.18). Cost barriers differed by location: urban HBC patients were three times more likely to report needing to pay to travel to the clinic than those on ART (RR: 2.84; 95% CI: 2.02-3.98) and 10 times more likely to believe they would need to pay a fee at the clinic (RR: 9.50; 95% CI: 2.24-40.3). In rural areas, HBC subjects were more likely to report needing to pay non-transport costs to attend the clinic than those on ART (RR: 4.52; 95% CI: 1.91-10.7). HBC patients were twice as likely as ART patients to report not having enough food to take ART being a concern (27% vs. 13%, RR: 2.03; 95% CI: 1.71-2.41), regardless of location and gender. Patients in home-based care for HIV/AIDS who never initiated ART perceived greater financial and logistical barriers to seeking HIV care and had more negative perceptions about the benefits of the treatment. Future efforts to expand access to antiretroviral care should consider ways to reduce these barriers in order to encourage more of those medically eligible

  16. Optically enhanced blood-brain-barrier crossing of plasmonic-active nanoparticles in preclinical brain tumor animal models

    Science.gov (United States)

    Yuan, Hsiangkuo; Wilson, Christy M.; Li, Shuqin; Fales, Andrew M.; Liu, Yang; Grant, Gerald; Vo-Dinh, Tuan

    2014-02-01

    Nanotechnology provides tremendous biomedical opportunities for cancer diagnosis, imaging, and therapy. In contrast to conventional chemotherapeutic agents where their actual target delivery cannot be easily imaged, integrating imaging and therapeutic properties into one platform facilitates the understanding of pharmacokinetic profiles, and enables monitoring of the therapeutic process in each individual. Such a concept dubbed "theranostics" potentiates translational research and improves precision medicine. One particular challenging application of theranostics involves imaging and controlled delivery of nanoplatforms across blood-brain-barrier (BBB) into brain tissues. Typically, the BBB hinders paracellular flux of drug molecules into brain parenchyma. BBB disrupting agents (e.g. mannitol, focused ultrasound), however, suffer from poor spatial confinement. It has been a challenge to design a nanoplatform not only acts as a contrast agent but also improves the BBB permeation. In this study, we demonstrated the feasibility of plasmonic gold nanoparticles as both high-resolution optical contrast agent and focalized tumor BBB permeation-inducing agent. We specifically examined the microscopic distribution of nanoparticles in tumor brain animal models. We observed that most nanoparticles accumulated at the tumor periphery or perivascular spaces. Nanoparticles were present in both endothelial cells and interstitial matrices. This study also demonstrated a novel photothermal-induced BBB permeation. Fine-tuning the irradiating energy induced gentle disruption of the vascular integrity, causing short-term extravasation of nanomaterials but without hemorrhage. We conclude that our gold nanoparticles are a powerful biocompatible contrast agent capable of inducing focal BBB permeation, and therefore envision a strong potential of plasmonic gold nanoparticle in future brain tumor imaging and therapy.

  17. Molecules of various pharmacologically-relevant sizes can cross the ultrasound-induced blood-brain barrier opening in vivo.

    Science.gov (United States)

    Choi, James J; Wang, Shougang; Tung, Yao-Sheng; Morrison, Barclay; Konofagou, Elisa E

    2010-01-01

    Focused ultrasound (FUS) is hereby shown to noninvasively and selectively deliver compounds at pharmacologically relevant molecular weights through the opened blood-brain barrier (BBB). A complete examination on the size of the FUS-induced BBB opening, the spatial distribution of the delivered agents and its dependence on the agent's molecular weight were imaged and quantified using fluorescence microscopy. BBB opening in mice (n=13) was achieved in vivo after systemic administration of microbubbles and subsequent application of pulsed FUS (frequency: 1.525MHz, peak-rarefactional pressure in situ: 570 kPa) to the left murine hippocampus through the intact skin and skull. BBB-impermeant, fluorescent-tagged dextrans at three distinct molecular weights spanning over several orders of magnitude were systemically administered and acted as model therapeutic compounds. First, dextrans of 3 and 70 kDa were delivered trans-BBB while 2000 kDa dextran was not. Second, compared with 70 kDa dextran, a higher concentration of 3 kDa dextran was delivered through the opened BBB. Third, the 3 and 70 kDa dextrans were both diffusely distributed throughout the targeted brain region. However, high concentrations of 70 kDa dextran appeared more punctated throughout the targeted region. In conclusion, FUS combined with microbubbles opened the BBB sufficiently to allow passage of compounds of at least 70 kDa, but not greater than 2000 kDa into the brain parenchyma. This noninvasive and localized BBB opening technique could, thus, provide a unique means for the delivery of compounds of several magnitudes of kDa that include agents with shown therapeutic promise in vitro but whose in vivo translation has been hampered by their associated BBB impermeability. (E-mail: ek2191@columbia.edu).

  18. Behavioral and neuropharmacological evidence that serotonin crosses the blood-brain barrier in Coturnix japonica (Galliformes; Aves

    Directory of Open Access Journals (Sweden)

    PA. Polo

    Full Text Available This study was carried out aiming to reach behavioral and neuropharmacological evidence of the permeability of the blood-brain barrier (BBB to serotonin systemically administered in quails. Serotonin injected by a parenteral route (250-1000 µg.kg-1, sc elicited a sequence of behavioral events concerned with a sleeping-like state. Sleeping-like behaviors began with feather bristling, rapid oral movements, blinking and finally crouching and closure of the eyes. Previous administration of 5-HT2C antagonist, LY53857 (3 mg.kg-1, sc reduced the episodes of feather bristling and rapid oral movements significantly but without altering the frequency of blinking and closure of the eyes. Treatment with the 5-HT2A/2C antagonist, ketanserin (3 mg.kg-1, sc did not affect any of the responses evoked by the serotonin. Quipazine (5 mg.kg-1, sc a 5-HT2A/2C/3 agonist induced intense hypomotility, long periods of yawning-like and sleeping-like states. Previous ketanserin suppressed gaping responses and reduced hypomotility, rapid oral movements and bristling but was ineffective for remaining responses induced by quipazine. Results showed that unlike mammals, serotonin permeates the BBB and activates hypnogenic mechanisms in quails. Studies using serotoninergic agonist and antagonists have disclosed that among the actions of the serotonin, feather bristling, rapid oral movements and yawning-like state originated from activation of 5-HT2 receptors while blinking and closure of the eyes possibly require other subtypes of receptors.

  19. New lager yeast strains generated by interspecific hybridization.

    Science.gov (United States)

    Krogerus, Kristoffer; Magalhães, Frederico; Vidgren, Virve; Gibson, Brian

    2015-05-01

    The interspecific hybrid Saccharomyces pastorianus is the most commonly used yeast in brewery fermentations worldwide. Here, we generated de novo lager yeast hybrids by mating a domesticated and strongly flocculent Saccharomyces cerevisiae ale strain with the Saccharomyces eubayanus type strain. The hybrids were characterized with respect to the parent strains in a wort fermentation performed at temperatures typical for lager brewing (12 °C). The resulting beers were analysed for sugar and aroma compounds, while the yeasts were tested for their flocculation ability and α-glucoside transport capability. These hybrids inherited beneficial properties from both parent strains (cryotolerance, maltotriose utilization and strong flocculation) and showed apparent hybrid vigour, fermenting faster and producing beer with higher alcohol content (5.6 vs 4.5 % ABV) than the parents. Results suggest that interspecific hybridization is suitable for production of novel non-GM lager yeast strains with unique properties and will help in elucidating the evolutionary history of industrial lager yeast.

  20. Predators induce interspecific herbivore competition for food in refuge space

    OpenAIRE

    Pallini, A.; Janssen, A.; Sabelis, M.W.

    1998-01-01

    Resource competition among herbivorous arthropods has long been viewed as unimportant because herbivore populations are controlled by predators. Although recently resurrected as an organizing force in arthropod communities on plants, there is still general agreement that resource competition among herbivores is reduced by predators. Here we show the reverse: predators induce interspecific resource competi-tion among herbivores. We found that thrips larvae (Frankliniella occidentalis) use the ...

  1. Interspecific variations in the gastrointestinal microbiota in penguins

    OpenAIRE

    Dewar, Meagan L; Arnould, John P Y; Dann, Peter; Trathan, Phil; Groscolas, Rene; Smith, Stuart

    2013-01-01

    Despite the enormous amount of data available on the importance of the gastrointestinal (GI) microbiota in vertebrate (especially mammals), information on the GI microbiota of seabirds remains incomplete. As with many seabirds, penguins have a unique digestive physiology that enables them to store large reserves of adipose tissue, protein, and lipids. This study used quantitative real-time polymerase chain reaction (qPCR) and 16S rRNA gene pyrosequencing to characterize the interspecific vari...

  2. Interleukin 7 from maternal milk crosses the intestinal barrier and modulates T-cell development in offspring.

    Directory of Open Access Journals (Sweden)

    Richard Aspinall

    Full Text Available Breastfeeding protects against illnesses and death in hazardous environments, an effect partly mediated by improved immune function. One hypothesis suggests that factors within milk supplement the inadequate immune response of the offspring, but this has not been able to account for a series of observations showing that factors within maternally derived milk may supplement the development of the immune system through a direct effect on the primary lymphoid organs. In a previous human study we reported evidence suggesting a link between IL-7 in breast milk and the thymic output of infants. Here we report evidence in mice of direct action of maternally-derived IL-7 on T cell development in the offspring.We have used recombinant IL-7 labelled with a fluorescent dye to trace the movement in live mice of IL-7 from the stomach across the gut and into the lymphoid tissues. To validate the functional ability of maternally derived IL-7 we cross fostered IL-7 knock-out mice onto normal wild type mothers. Subsets of thymocytes and populations of peripheral T cells were significantly higher than those found in knock-out mice receiving milk from IL-7 knock-out mothers.Our study provides direct evidence that interleukin 7, a factor which is critical in the development of T lymphocytes, when maternally derived can transfer across the intestine of the offspring, increase T cell production in the thymus and support the survival of T cells in the peripheral secondary lymphoid tissue.

  3. Interspecific Plastome Recombination Reflects Ancient Reticulate Evolution in Picea (Pinaceae).

    Science.gov (United States)

    Sullivan, Alexis R; Schiffthaler, Bastian; Thompson, Stacey Lee; Street, Nathaniel R; Wang, Xiao-Ru

    2017-07-01

    Plastid sequences are a cornerstone in plant systematic studies and key aspects of their evolution, such as uniparental inheritance and absent recombination, are often treated as axioms. While exceptions to these assumptions can profoundly influence evolutionary inference, detecting them can require extensive sampling, abundant sequence data, and detailed testing. Using advancements in high-throughput sequencing, we analyzed the whole plastomes of 65 accessions of Picea, a genus of ∼35 coniferous forest tree species, to test for deviations from canonical plastome evolution. Using complementary hypothesis and data-driven tests, we found evidence for chimeric plastomes generated by interspecific hybridization and recombination in the clade comprising Norway spruce (P. abies) and 10 other species. Support for interspecific recombination remained after controlling for sequence saturation, positive selection, and potential alignment artifacts. These results reconcile previous conflicting plastid-based phylogenies and strengthen the mounting evidence of reticulate evolution in Picea. Given the relatively high frequency of hybridization and biparental plastid inheritance in plants, we suggest interspecific plastome recombination may be more widespread than currently appreciated and could underlie reported cases of discordant plastid phylogenies. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  4. Barriers and facilitators to care for the terminally ill: a cross-country case comparison study of Canada, England, Germany, and the United States.

    Science.gov (United States)

    Klinger, Christopher A; Howell, Doris; Zakus, David; Deber, Raisa B

    2014-02-01

    Why do many patients not die at their preferred location? Analyze system-level characteristics influencing the ability to implement best practices in delivering care for terminally ill adults (barriers and facilitators). Cross-country comparison study from a "most similar-most different" perspective, triangulating evidence from a scoping review of the literature, document analyses, and semi-structured key informant interviews. Case study of Canada, England, Germany, and the United States. While similar with regard to leading causes of death, patient needs, and potential avenues to care, different models of service provision were employed in the four countries studied. Although hospice and palliative care services were generally offered with standard care along the disease continuum and in various settings, and featured common elements such as physical, psycho-social, and spiritual care, outcomes (access, utilization, etc.) varied across jurisdictions. Barriers to best practice service provision included legislative (including jurisdictional), regulatory (e.g. education and training), and financial issues as well as public knowledge and perception ("giving up hope") challenges. Advance care planning, dedicated and stable funding toward hospice and palliative care, including caregiver benefits, population aging, and standards of practice and guidelines to hospice and palliative care, were identified as facilitators. Successful implementation of effective and efficient best practice approaches to care for the terminally ill, such as shared care, requires concerted action to align these system-level characteristics; many factors were identified as being essential but not sufficient. Policy implementation needs to be tailored to the respective health-care system(s), monitored, and fine-tuned.

  5. Interspecific aggression, not interspecific mating, drives character displacement in the wing coloration of male rubyspot damselflies (Hetaerina)

    Science.gov (United States)

    Drury, J. P.; Grether, G. F.

    2014-01-01

    Traits that mediate intraspecific social interactions may overlap in closely related sympatric species, resulting in costly between-species interactions. Such interactions have principally interested investigators studying the evolution of reproductive isolation via reproductive character displacement (RCD) or reinforcement, yet in addition to reproductive interference, interspecific trait overlap can lead to costly between-species aggression. Previous research on rubyspot damselflies (Hetaerina spp.) demonstrated that sympatric shifts in male wing colour patterns and competitor recognition reduce interspecific aggression, supporting the hypothesis that agonistic character displacement (ACD) drove trait shifts. However, a recent theoretical model shows that RCD overshadows ACD if the same male trait is used for both female mate recognition and male competitor recognition. To determine whether female mate recognition is based on male wing coloration in Hetaerina, we conducted a phenotype manipulation experiment. Compared to control males, male H. americana with wings manipulated to resemble a sympatric congener (H. titia) suffered no reduction in mating success. Thus, female mate recognition is not based on species differences in male wing coloration. Experimental males did, however, experience higher interspecific fighting rates and reduced survival compared to controls. These results greatly strengthen the case for ACD and highlight the mechanistic distinction between ACD and RCD. PMID:25339724

  6. Identification of interspecific hybrids between loquat (eriobotrya japonica lindl.) and bengal loquat (e. bengalensis hook.)

    International Nuclear Information System (INIS)

    Wang, Y.; Deng, Q.; Zeng, J.; Zhang, J.

    2017-01-01

    Loquat (Eriobotrya japonica Lindl.) is an important subtropical fruit; however, loquat fruitlets are vulnerable to cold injury in winter, which significantly decreases loquat yield in most production regions. In the present study, two loquat cultivars ('Dawuxing' and '4-1-5') and one wild loquat (E. bengalensis Hook., Bengal loquat), were used for interspecific hybridization to produce hybrids with characteristics of spring blooming to avoid cold injury of fruitlets. Hybrid seedlings were derived from direct cross (loquat as female parent and Bengal loquat as male parent) and reciprocal cross. The authenticity of 47 hybrid seedlings was confirmed using inter-simple sequence repeat (ISSR) molecular markers; and leaf morphological characteristics of the hybrid offspring and parents were preliminarily studied and compared. The results suggested that 23 true direct cross hybrids and 12 true reciprocal cross hybrids were obtained, with hybrid authenticity rates of 100 and 50.0%, respectively. Thus, a novel method of distant hybridization for loquat breeding was developed, and with their various genetic and morphological characteristics these hybrids could be valuable germplasms for horticultural use. (author)

  7. Efficacy of NGR peptide-modified PEGylated quantum dots for crossing the blood-brain barrier and targeted fluorescence imaging of glioma and tumor vasculature.

    Science.gov (United States)

    Huang, Ning; Cheng, Si; Zhang, Xiang; Tian, Qi; Pi, Jiangli; Tang, Jun; Huang, Qing; Wang, Feng; Chen, Jin; Xie, Zongyi; Xu, Zhongye; Chen, Weifu; Zheng, Huzhi; Cheng, Yuan

    2017-01-01

    Delivery of imaging agents to brain glioma is challenging because the blood-brain barrier (BBB) functions as a physiological checkpoint guarding the central nervous system from circulating large molecules. Moreover, the ability of existing probes to target glioma has been insufficient and needs to be improved. In present study, PEG-based long circulation, CdSe/ZnS quantum dots (QDs)-based nanoscale and fluorescence, asparagines-glycine-arginine peptides (NGR)-based specific CD13 recognition were integrated to design and synthesize a novel nanoprobe by conjugating biotinylated NGR peptides to avidin-PEG-coated QDs. Our data showed that the NGR-PEG-QDs were nanoscale with less than 100 nm and were stable in various pH (4.0~8.0). These nanomaterials with non-toxic concentrations could cross the BBB and target CD13-overexpressing glioma and tumor vasculature in vitro and in vivo, contributing to fluorescence imaging of this brain malignancy. These achievements allowed groundbreaking technological advances in targeted fluorescence imaging for the diagnosis and surgical removal of glioma, facilitating potential transformation toward clinical nanomedicine. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Reaction cross sections and elastic scattering energy dependence around the Coulomb barrier for the {sup 7}Be+{sup 27}Al system

    Energy Technology Data Exchange (ETDEWEB)

    Morcelle, Viviane; Gomes, P.R.S.; Lubian, J.; Mendes Junior, D.R. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Lichtenthaeler, R.; Guimaraes, V.; Lepine-Szily, A.; Camargo, O.; Faria, P.N. de; Gasquez, L.; Morais, M.C.; Condori, R.P.; Pires, K.C.C.; Scarduelli, V. [Universidade de Sao Paulo (USP), SP (Brazil); Barioni, A. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil); Shorto, J.M.B. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Zamora, J.C. [Technische Universitaet Darmstadt (Germany); Aguilera, E.; Martinez-Quiroz, E. [Instituto Nacional de Investigaciones Nucleares (Mexico); Kolata, J.; Jiang, H. [University of Notre Dame, IN (United States); Bechetti, F.D.; Lamm, L.O. [Michigan University, MI (United States); Lizcano, D. [Universidad Autonoma del Estado de Mexico (Mexico)

    2012-07-01

    Full text: Elastic scattering measurements were performed at energies around the Coulomb barrier at the Tandem Accelerators of the Sao Paulo (USP - Brazil ) and Notre Dame (UND - USA) Universities. The {sup 7}Be is a radioactive nucleus and has been produced by the reaction {sup 6}He({sup 6}Li,{sup 9}Be) and impinged on {sup 27}Al and {sup 197}Au secondary targets using a double superconducting systems RIBRAS ( USP ) and Twinsol (UND). The elastic scattering angular distributions were analyzed through the optical model calculations, using the Woods- Saxon form factors [1] and the Sao Paulo potential [2] to fit the experimental data. The total reaction cross sections were also derived and compared with others presented at the literature for other systems. In addition, a study of the nuclear potential energy dependence has been carried out in this work in the dispersion relation context. Due to the fact that {sup 7}Be has a small breakup threshold energy, the results can provide significant information of the influence of the breakup channel on the reactions involving this projectile. For this purpose, {chi}{sup 2}- data analysis with different kind of potentials were performed to identify the energy dependence of the real (V) and imaginary (W) parts of the potential. [1] L.C. Chamon et al., Phys. Rev. C 66, (2002) 014610. [2] R.D. Wood e D.S. Saxon, Phys. Rev. 95 ( 1954) 577. (author)

  9. Method for evaluating the potential of 14C labeled plant polyphenols to cross the blood-brain barrier using accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Janle, Elsa M.; Lila, Mary Ann; Grannan, Michael; Wood, Lauren; Higgins, Aine; Yousef, Gad G.; Rogers, Randy B.; Kim, Helen; Jackson, George S.; Weaver, Connie M.

    2010-01-01

    Bioactive compounds in botanicals may be beneficial in preventing age-related neurodegenerative diseases, but for many compounds conventional methods may be inadequate to detect if these compounds cross the blood-brain barrier or to track the pharmacokinetics in the brain. By combining a number of unique technologies it has been possible to utilize the power of AMS to study the pharmacokinetics of bioactive compounds in the brain at very low concentrations. 14 C labeled compounds can be biosynthesized by plant cell suspension cultures co-incubated with radioisotopically-labeled sucrose and isolated and separated into a series of bioactive fractions. To study the pharmacokinetics and tissue distribution of 14 C labeled plant polyphenols, rats were implanted with jugular catheters, subcutaneous ultrafiltration probes and brain microdialysis probes. Labeled fractions were dosed orally. Interstitial fluid (ISF) and brain microdialysate samples were taken in tandem with blood samples. It was often possible to determine 14 C in blood and ISF with a β-counter. However, brain microdialysate samples 14 C levels on the order of 10 7 atoms/sample required AMS technology. The Brain Microdialysate AUC /Serum AUC ranged from .021- to .029, with the higher values for the glycoside fractions. By using AMS in combination with traditional methods, it is possible to study uptake by blood, distribution to ISF and determine the amount of a dose which can reach the brain and follow the pharmacokinetics in the brain.

  10. Induction of Tetraploid Male Sterile Tagetes erecta by Colchicine Treatment and Its Application for Interspecific Hybridization

    Directory of Open Access Journals (Sweden)

    Yanhong He

    2016-09-01

    Full Text Available Tagetes erecta is an annual multifunctional plant which can be cultivated under a broad range of climatic conditions. Polyploidization and interspecific hybridization are applied to facilitate breeding cultivars of T. erecta with improved ornamental qualities. Colchicine treatment to the germinating seeds was proved to be a useful tool for chromosome doubling of the male sterile two-type line ‘M525AB’, with the resulting frequency of polyploid seedlings ranging from 88.89% (following 0.05% w/v colchicine applied for a 3–6 h exposure period to a maximum of 100.00% (following 0.1% for 3–6 h, or 0.2% for 3 h. Morphological observation, stomatal size and density analysis, flow cytometric analysis and chromosome counting were conducted to identify the tetraploid plants. Distinctive morphological changes were observed in a notable proportion of polyploid plants. The colchicine-treated polyploid T. erecta plants showed dwarfed and more robust growth, thicker, larger and greener leaves, larger inflorescences and florets. The mutant plants identified through morphological observation all aligned as polyploid plants, thus morphological observation could be an effective method for the detection of polyploidy. The polyploid plants had significant larger stomata size over the abaxial leaf surface, whereas the density of stomata distribution was remarkably reduced. The survival rate of tetraploid cuttings (i.e. 38% was greatly reduced compared to that of diploid plants. The fertility of tetraploid plants was also decreased, as shown by cross-pollination yields. Interspecific hybridizations between colchicine-induced tetraploid plants of a male sterile T. erecta line and the naturally tetraploid fully fertile Tagetes patula species resulted in hybrid progeny. Most of these hybrids displayed the dwarfed growth stature and compact, larger-flower morphology which is the typical ideotype of herbaceous flowers. Thus, polyploidization may be employed

  11. Plant breeding by using radiation mutation - Development of disease tolerant lines of hotpepper by using radiation and interspecific hybridization

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yong Su; Song, Hi Sup; Kim, Jin Kyu; Shin, In Chul [Nongwoo Seed Co., Suwon (Korea)

    2000-04-01

    To obtain disease resistant mutant lines, 6 inbred lines were hotppepers were irradiated with 250Gy of gamma ray and crossed between cultivar and wild species. 1) 4500 M{sub 1} plants were cultivated for obtaining M{sub 2} seed in 6 inbred lines of hotpeppers irradiated with 250 Gy of gamma ray. 2) Crossability was not generally existed among interspecific crosses, crossability between C. annum and C. chacoense was successful except crosses between C. annum, C. pubescens and C. eximium. 3) The embryo disected 45 days after pollination was suitable for embryo culture. 4) Hybrid plants were obtained from the embryo culture of the combination between C. annum and C. chacoense, while abnormal hybrid plants occurred from the combination between C. annum and C. baccatum. 15 refs., 4 figs., 4 tabs. (Author)

  12. Interspecific variation of ontogeny and skull shape among porpoises (Phocoenidae).

    Science.gov (United States)

    Galatius, Anders; Berta, Annalisa; Frandsen, Marie Schou; Goodall, R Natalie P

    2011-02-01

    All extant members of Phocoenidae (porpoises) have been characterized as pedomorphic based on skeletal characters. To investigate the ontogenetic background for pedomorphosis and assess interspecific differences in ontogeny among phocoenids, samples of the six extant species were compared in terms of development of both epiphyseal and cranial suture fusion. Across all species, full maturity of the vertebral column was rare. Vertebral epiphyseal development did not progress so far in most Phocoena phocoena as in Phocoenoides dalli and Phocoena dioptrica. P. phocoena, Phocoena spinipinnis, Ph. dalli, and P. dioptrica, for which large series were available, were further compared in terms of ontogeny of cranial shape by three-dimensional geometric morphometrics. Ph. dalli and P. dioptrica generally showed further development of cranial sutures than the other species. Postnatal skull shape development was similar for all species studied; the majority of interspecific shape differences are present at parturition. Smaller species had a higher rate of shape development relative to growth in size than Ph. dalli and P. dioptrica, but they still showed less allometric development due to less postnatal growth. Interspecific shape differences indicate phylogenetic relationships similar to that proposed based on morphology or convergent evolution of the two pelagic species, Ph. dalli and P. dioptrica, under the scenarios suggested by recent molecular studies. A shape trend coinciding with habitat preference was detected; in species with pelagic preference the position and orientation of the foramen magnum aligned the skull with the vertebral column; the rostrum showed less ventral inclination, and the facial region was larger and more concave in lateral aspect. Copyright © 2010 Wiley-Liss, Inc.

  13. Assessing hybrid sterility in Oryza glaberrima x O. sativa hybrid progenies by PCR marker analysis and crossing with wide compatibility varieties.

    Science.gov (United States)

    Heuer, Sigrid; Miézan, Kouamé M

    2003-09-01

    Interspecific crossing of the African indigenous rice Oryza glaberrima with Oryza sativa cultivars is hindered by crossing barriers causing 100% spikelet sterility in F(1) hybrids. Since hybrids are partially female fertile, fertility can be restored by back crossing (BC) to a recurrent male parent. Distinct genetic models on spikelet sterility have been developed predicting, e.g., the existence of a gamete eliminator and/or a pollen killer. Linkage of sterility to the waxy starch synthase gene and the chromogen gene C, both located on chromosome 6, have been demonstrated. We selected a segregating BC(2)F(3) population of semi-sterile O. glaberrima x O. sativa indica hybrid progenies for analyses with PCR markers located at the respective chromosome-6 region. These analyses revealed that semi-sterile plants were heterozygous for a marker (OSR25) located in the waxy promoter, whereas fertile progenies were homozygous for the O. glaberrima allele. Adjacent markers showed no linkage to spikelet sterility. Semi-sterility of hybrid progenies was maintained at least until the F(4) progeny generation, suggesting the existence of a pollen killer in this plant material. Monitoring of reproductive plant development showed that spikelet sterility was at least partially due to an arrest of pollen development at the microspore stage. In order to address the question whether genes responsible for F(1) sterility in intraspecific hybrids ( O. sativa indica x japonica) also cause spikelet sterility in interspecific hybrids, crossings with wide compatibility varieties (WCV) were performed. WCV accessions possess "neutral" S-loci ( S(n)) improving fertility in intraspecific hybrids. This experiment showed that the tested S(n)-loci had no fertility restoring effect in F(1) interspecific hybrids. Pollen development was completely arrested at the microspore stage and grains were never obtained after selfing. This suggests that distinct or additional S-loci are responsible for sterility

  14. Coexistence facilitates interspecific biofilm formation in complex microbial communities

    DEFF Research Database (Denmark)

    Madsen, Jonas Stenløkke; Røder, Henriette Lyng; Russel, Jakob

    2016-01-01

    Social interactions in which bacteria respond to one another by modifying their phenotype are central determinants of microbial communities. It is known that interspecific interactions influence the biofilm phenotype of bacteria; a phenotype that is central to the fitness of bacteria. However......, the underlying role of fundamental ecological factors, specifically coexistence and phylogenetic history, in biofilm formation remains unclear. This study examines how social interactions affect biofilm formation in multi-species co-cultures from five diverse environments. We found prevalence of increased...

  15. Barriers and facilitators for the implementation of an online clinical health community in addition to usual fertility care: a cross-sectional study.

    Science.gov (United States)

    Aarts, Johanna W M; Faber, Marjan J; den Boogert, Anne G; Cohlen, Ben J; van der Linden, Paul J Q; Kremer, Jan A M; Nelen, Willianne L D M

    2013-08-30

    Online health communities are becoming more popular in health care. Patients and professionals can communicate with one another online, patients can find peer support, and professionals can use it as an additional information channel to their patients. However, the implementation of online health communities into daily practice is challenging. These challenges relate to the fact that patients need to be activated to (1) become a member (ie, subscription) and (2) participate actively within the community before any effect can be expected. Therefore, we aimed at answering 2 research questions: (1) what factors are associated with subscription to an online health community, and (2) which are associated with becoming an active participant within an online health community. To identify barriers and facilitators as perceived by patients for the implementation of an online health community. We performed a cross-sectional study. Three Dutch fertility clinics (2 IVF-licensed) offered their patients a secure online clinical health community through which clinicians can provide online information and patients can ask questions to the medical team or share experiences and find support from peers. We randomly selected and invited 278 men and women suffering from infertility and attending 1 of the participating clinics. Participants filled out a questionnaire about their background characteristics and current use of the online community. Possible barriers and facilitators were divided into 2 parts: (1) those for subscription to the community, and (2) those for active participation in the community. We performed 2 multivariate logistic regression analyses to calculate determinants for both subscription and active participation. Subscription appeared to be associated with patients' background characteristics (eg, gender, treatment phase), intervention-related facilitators (odds ratio [OR] 2.45, 95% CI 1.14-5.27), and patient-related barriers (OR 0.20, 95% CI 0.08-0.54), such as

  16. Prevalence, barriers and factors associated with parental disclosure of their HIV positive status to children: a cross-sectional study in an urban clinic in Kampala, Uganda

    Directory of Open Access Journals (Sweden)

    Charles Peter Osingada

    2016-07-01

    Full Text Available Abstract Background Disclosure of parental HIV status is associated with a number of positive outcomes such as improved adherence to clinic appointments, lower levels of parental anxiety and depression, and mutual emotional support between parents and their children. Very few studies in low-resource settings have addressed the issues of parental disclosure of their HIV status to their children. Methods A cross-sectional study was conducted among adult parents attending HIV/AIDS prevention, care and treatment clinic at Makerere University Infectious Diseases Institute (IDI, Kampala, Uganda. Participants were interviewed using the Parent Disclosure Interview (PDI questionnaire which is a standard tool developed specifically for HIV infected parents. Data were analyzed using STATA version 13.1. Results Of 344 participants, only 37 % had told at least one of their children that they were HIV positive. Barriers to disclosure were fear that children may tell other people about the parent’s HIV status, desire not to worry or upset children and perceptions that children may not understand. Age of the parent, religion and having someone committed to care of the children were positively associated with parental disclosure of their HIV positives status. Attainment of tertiary level of education was negatively associated with parental disclosure of their HIV status. Conclusions Parental disclosure of a positive HIVstatus to their children is still low in urban Kampala. There is therefore need to develop locally relevant interventions so as to increase rates of parental disclosure of a positive HIV status to their children and thus promote open and honest discussions about HIV/AIDS at family level.

  17. Prevalence, barriers and factors associated with parental disclosure of their HIV positive status to children: a cross-sectional study in an urban clinic in Kampala, Uganda.

    Science.gov (United States)

    Osingada, Charles Peter; Okuga, Monica; Nabirye, Rose Chalo; Sewankambo, Nelson Kaulukusi; Nakanjako, Damalie

    2016-07-11

    Disclosure of parental HIV status is associated with a number of positive outcomes such as improved adherence to clinic appointments, lower levels of parental anxiety and depression, and mutual emotional support between parents and their children. Very few studies in low-resource settings have addressed the issues of parental disclosure of their HIV status to their children. A cross-sectional study was conducted among adult parents attending HIV/AIDS prevention, care and treatment clinic at Makerere University Infectious Diseases Institute (IDI), Kampala, Uganda. Participants were interviewed using the Parent Disclosure Interview (PDI) questionnaire which is a standard tool developed specifically for HIV infected parents. Data were analyzed using STATA version 13.1. Of 344 participants, only 37 % had told at least one of their children that they were HIV positive. Barriers to disclosure were fear that children may tell other people about the parent's HIV status, desire not to worry or upset children and perceptions that children may not understand. Age of the parent, religion and having someone committed to care of the children were positively associated with parental disclosure of their HIV positives status. Attainment of tertiary level of education was negatively associated with parental disclosure of their HIV status. Parental disclosure of a positive HIVstatus to their children is still low in urban Kampala. There is therefore need to develop locally relevant interventions so as to increase rates of parental disclosure of a positive HIV status to their children and thus promote open and honest discussions about HIV/AIDS at family level.

  18. Multiple barriers against successful care provision for depressed patients in general internal medicine in a Japanese rural hospital: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Saitoh Akiyoshi

    2010-04-01

    Full Text Available Abstract Background A general internist has an important role in primary care, especially for the elderly in rural areas of Japan. Although effective intervention models for depressed patients in general practice and primary care settings have been developed in the US and UK medical systems, there is little information regarding even the recognition rate and prescription rate of psychotropic medication by general internists in Japan. The present study surveyed these data cross-sectionally in a general internal medicine outpatient clinic of a Japanese rural hospital. Methods Patients were consecutively recruited and evaluated for major depressive disorder or any mood disorder using the Patient Health Questionnaire (PHQ. Physicians who were blinded to the results of the PHQ were asked to diagnose whether the patients had any mental disorders, and if so, whether they had mood disorders or not. Data regarding prescription of psychotropic medicines were collected from medical records. Results Among 312 patients, 27 (8.7% and 52 (16.7% were identified with major depressive disorder and any mood disorder using the PHQ, respectively. Among those with major depressive disorder, 21 (77.8% were recognized by physicians as having a mental disorder, but only three (11.1% were diagnosed as having a mood disorder. Only two patients with major depressive disorder (7.4% had been prescribed antidepressants. Even among those (n = 15 whom physicians diagnosed with a mood disorder irrespective of the PHQ results, only four (26.7% were prescribed an antidepressant. Conclusions Despite a high prevalence of depression, physicians did not often recognize depression in patients. In addition, most patients who were diagnosed by physicians as having a mood disorder were not prescribed antidepressants. Multiple barriers to providing appropriate care for depressed patients exist, such as recognizing depression, prescribing appropriate medications, and appropriately referring

  19. The pharmacokinetics of xylazine hydrochloride: an interspecific study.

    Science.gov (United States)

    Garcia-Villar, R; Toutain, P L; Alvinerie, M; Ruckebusch, Y

    1981-06-01

    The pharmacokinetic disposition of xylazine hydrochloride is described after both intravenous and intramuscular injection of a single dose, in four domestic species: horse, cattle, sheep and dog, by an original high performance liquid chromatographic technique. Remarkably small interspecific differences are reported. After intravenous administration, systemic half-life (t1/2 beta) ranged between 22 min (sheep) and 50 min (horse) while the distribution phase is transient with half-life (t1/2 alpha) ranging from 1.2 min (cattle) to 5.9 min (horse). The peak level of drug concentration in the plasma is reached after 12-14 min in all the species studied following intramuscular administration. Xylazine bioavailability, as measured by the ratios of the areas under the intravenous and intramuscular plasma concentration versus time curves, ranged from 52% to 90% in dog, 17% to 73% in sheep and 40% to 48% in horse. The low dosage in cattle did not permit calculation. Kinetic data are correlated with clinical data and the origins of interspecific differences are discussed.

  20. Snake co-occurrence patterns are best explained by habitat and hypothesized effects of interspecific interactions

    Science.gov (United States)

    David A. Steen; Christopher J. W. McClure; Jean C. Brock; D. Craig Rudolph; Josh B. Pierce; James R. Lee; W. Jeffrey Humphries; Beau B. Gregory; William B. Sutton; Lora L. Smith; Danna L. Baxley; Dirk J. Stevenson; Craig Guyer

    2014-01-01

    1. Snakes often occur in species-rich assemblages, and sympatry is thought to be facilitated primarily by low diet overlap, not interspecific interactions. 2. We selected, a priori, three species pairs consisting of species that are morphologically and taxonomically similar and may therefore be likely to engage in interspecific, consumptive competition. We then...

  1. Using DNA to describe and quantify interspecific killing of fishers in California

    Science.gov (United States)

    Greta M. Wengert; Mourad W. Gabriel; Sean M. Matthews; J. Mark Higley; Rick A. Sweitzer; Craig. M. Thompson; Kathryn L. Purcell; Reginald H. Barrett; Leslie W. Woods; Rebecca E. Green; Stefan M. Keller; Patricia M. Gaffney; Megan Jones; Benjamin N. Sacks

    2014-01-01

    Interspecific killing is common among carnivores and can have population-level effects on imperiled species. The fisher (Pekania [Martes] pennant) is a rare forest carnivore in western North America and a candidate for listing under the United States Endangered Species Act. Interspecific killing and...

  2. Skin barrier composition

    International Nuclear Information System (INIS)

    Osburn, F.G.

    1985-01-01

    A skin barrier composition comprises a mixture of a copolymer resin of ethylene and vinyl acetate (EVA), and a water-insoluble dry tack-providing elastomer such as polyisobutylene. The composition after mixing and molding, is subjected to ionizing irradiation to form cross-linked polymer networks of the EVA. The compositions have exceptional properties for use as barrier sheets, rings, or strips in ostomy, wound drainage, and incontinence devices. (author)

  3. Skin barrier composition

    Energy Technology Data Exchange (ETDEWEB)

    Osburn, F G

    1985-06-12

    A skin barrier composition comprises a mixture of a copolymer resin of ethylene and vinyl acetate (EVA), and a water-insoluble dry tack-providing elastomer such as polyisobutylene. The composition after mixing and molding, is subjected to ionizing irradiation to form cross-linked polymer networks of the EVA. The compositions have exceptional properties for use as barrier sheets, rings, or strips in ostomy, wound drainage, and incontinence devices.

  4. Interspecific competition of early successional plant species in ex-arable fields as influenced by plant-soil feedback

    OpenAIRE

    Jing, Jingying; Bezemer, T. Martijn; Van der Putten, Wim H.

    2015-01-01

    Plant–soil feedback can affect plants that belong to the same (intraspecific feedback) or different species (interspecific feedback). However, little is known about how intra- and interspecific plant–soil feedbacks influence interspecific plant competition. Here, we used plants and soil from early-stage ex-arable fields to examine how intra- and interspecific plant–soil feedbacks affect the performance of 10 conditioning species and the focal species, Jacobaea vulgaris. Plants were grown alon...

  5. Knowledge and exercise of human rights, and barriers and facilitators to claiming rights: a cross-sectional study of female sex workers and high-risk men who have sex with men in Andhra Pradesh, India

    OpenAIRE

    Ganju, Deepika; Patel, Sangram Kishor; Prabhakar, Parimi; Adhikary, Rajatashurva

    2016-01-01

    Background HIV prevention interventions recognize the need to protect the rights of key populations and support them to claim their rights as a vulnerability reduction strategy. This study explores knowledge of human rights, and barriers and facilitators to claiming rights, among female sex workers (FSWs) and high-risk men who have sex with men (HR-MSM) who are beneficiaries of a community mobilization intervention in Andhra Pradesh, India. Methods Data are drawn from a cross-sectional survey...

  6. Adaptation of bacteriophages to new hosts through overcoming the interspecific barrier

    Directory of Open Access Journals (Sweden)

    Е. N. Andriychuk

    2016-10-01

    Full Text Available Four wild type phage isolates were tested on P. syringae isolated from potato tuber samples collected in the Kiev and Cherkasy regions of Ukraine. The isolated phages formed clear plaques and had a virion size of 2 to 12 nm. Electron microscopy showed that the phages were of similar size and structure and consisted of isometric particles with long tails characteristic of the Podoviridae family. The effectiveness of phage culturing on bacteria different from the original host was also studied on two phytopathogenic strains of Pseudomonas savastanoi pv. рhaseolicola 4013 and P. syringae pv. tabaci 223. However, no stable isolates could be extracted from P. savastanoi pv. phaseolicola as the plages became inactive after a few passages on the bacterial culture. In order to overcome this, the phages were first cultured on P. syringae pv. tabaci before being transferred to P. savastanoi pv. рhaseolicola. The titers obtained were compared with phage titers from the original host bacteria. Thus, it was determined that the changes occuring in phages after their transfer to the Pseudomonas strain 4013 were irreversible. The changes were evaluated by comparing the effectiveness of phage culturing after a cycle of passages on strains 4013 and 223 where the phages were adapted to strain 4013 after being cultured on strain 223. Additionally, the effectiveness of phage culturing on strain 223 was also determined. The change in the effectiveness of phage culturing for the entire phage range suggests the presence of a defensive system in bacteria when the phages were transferred from strain 223 to strain 4013. The irreversibility of the changes occuring in phages was also tested and it was determined that phages 223/4 and 7591/2 adapt to original hosts and swiftly restore their original titers. Phage 7591/1, however, showed titers that were lower than the ones obtained from the original host culture. The testing of the irreversibility of changes in phages after culturing on P. savastanoi pv. phaseolicola was then tested and the results showed that three phage isolates adapted to their original hosts quickly, but not isolate 7591/1. A possible explanation in this case could be a gradual adaptation of the phages to bacteria through a large number of reproductive cycles.

  7. Interspecific competition of early successional plant species in ex-arable fields as influenced by plant–soil feedback

    NARCIS (Netherlands)

    Jing, Y.; Bezemer, T.M.; Putten, van der W.H.

    2015-01-01

    Plant–soil feedback can affect plants that belong to the same (intraspecific feedback) or different species (interspecific feedback). However, little is known about how intra- and interspecific plant–soil feedbacks influence interspecific plant competition. Here, we used plants and soil from

  8. Interspecific competition of early successional plant species in ex-arable fields as influenced by plant-soil feedback

    NARCIS (Netherlands)

    Jing, Jingying; Bezemer, T. Martijn; Van der Putten, Wim H.

    2015-01-01

    Plant–soil feedback can affect plants that belong to the same (intraspecific feedback) or different species (interspecific feedback). However, little is known about how intra- and interspecific plant–soil feedbacks influence interspecific plant competition. Here, we used plants and soil from

  9. Potential role of tele-rehabilitation to address barriers to implementation of physical therapy among West African stroke survivors: A cross-sectional survey.

    Science.gov (United States)

    Sarfo, Fred S; Adamu, Sheila; Awuah, Dominic; Sarfo-Kantanka, Osei; Ovbiagele, Bruce

    2017-10-15

    The greatest burden from stroke-related disability is borne by Low-and-Middle Income countries (LMICs) where access to rehabilitation after stroke is severely challenged. Tele-rehabilitation could be a viable avenue to address unmet rehabilitation needs in LMICs. To assess the burden of post-stroke physical deficits, rates of utilization of physiotherapy services, and perceptions of tele-rehabilitation among recent Ghanaian stroke survivors. Using a consecutive sampling strategy, 100 stroke survivors attending an outpatient Neurology clinic in a Ghanaian tertiary medical center were enrolled into this cross-sectional study. After collecting basic demographic data, clinical history on stroke type, severity and level of disability, we administered the validated 20-item Functional Independence Measure questionnaire to evaluate functional status of study participants and an 8-item questionnaire to assess participants' attitudes towards telemedicine administered rehabilitation intervention. Mean±SD age of study participants was 57.2±13.3years of which 51.0% were males with a mean duration of stroke of 1.3±2.2years. 53% had Modified Rankin scores of ≥3, 57% were fully independent and only 27% reported utilizing any physiotherapy services. Barriers to access to physiotherapy included financial constraints due to cost of physiotherapy services and transportation as well as premature discharge from physiotherapy to avoid overburdening of available physiotherapy services. These factors led to the limited provision of rehabilitative therapy. Participants held positive views of the potential for tele-rehabilitation interventions (80-93%). However, while 85% owned mobile phones, only 35% had smart phones. Despite, a high burden of residual disability, only about 1 out of 4 stroke patients in this Ghanaian cohort was exposed to post-stroke physiotherapy services, largely due to relatively high costs and limited health system resources. These Ghanaian stroke patients viewed

  10. New indices for home nursing care resource disparities in rural and urban areas, based on geocoding and geographic distance barriers: a cross-sectional study.

    Science.gov (United States)

    Lin, Shyang-Woei; Yen, Chia-Feng; Chiu, Tzu-Ying; Chi, Wen-Chou; Liou, Tsan-Hon

    2015-10-08

    Aging in place is the crucial object of long-term care policy worldwide. Approximately 15.6-19.4% of people aged 15 or above live with a disability, and 15.3% of them have moderate or severe disabilities. The allocation of home nursing care services is therefore an important issue. Service providers in Taiwan vary substantially across regions, and between rural and urban areas. There are no appropriate indices for describing the capacity of providers that it is due to the distances from care recipients. This study therefore aimed to describe and compare distance barriers for home nursing care providers using indices of the "profit willing distance" and the "tolerance limited distance". This cross-sectional study was conducted during 2012 and 2013 using geocoding and a geographic information system to identify the distance from the providers' locations to participants' homes in urban (Taipei City) and rural (Hualien County) areas in Taiwan. Data were collected in-person by professionals in Taiwanese hospitals using the World Health Organization Disability Assessment Schedule 2.0. The indices were calculated using regression curves, and the first inflection points were determined as the points on the curves where the first and second derivatives equaled 0. There were 5627 participants from urban areas and 956 from rural areas. In urban areas, the profit willing distance was 550-600 m, and we were unable to identify them in rural areas. This demonstrates that providers may need to supply services even when there is little profit. The tolerance limited distance were 1600-1650 m in urban areas and 1950-2000 m in rural areas. In rural areas, 33.3% of those living inside the tolerance limited distance and there was no provider within this distance, but this figure fell to just 13.9% in urban areas. There were strong disparities between urban and rural areas in home nursing care resource allocation. Our new "profit willing distance" and the "tolerance limited distance" are

  11. Interspecific bacterial interactions are reflected in multispecies biofilm spatial organization

    DEFF Research Database (Denmark)

    Liu, Wenzheng; Røder, Henriette Lyng; Madsen, Jonas Stenløkke

    2016-01-01

    not only the enabling sub-populations. However, the specific molecular mechanisms of cellular processes affecting spatial organization, and vice versa, are poorly understood and very complex to unravel. Therefore, detailed description of the spatial organization of individual bacterial cells...... environments. Species residing in these complex bacterial communities usually interact both intra- and interspecifically. Such interactions are considered to not only be fundamental in shaping overall biomass and the spatial distribution of cells residing in multispecies biofilms, but also to result......, industrial, and clinical implications. This review briefly presents the state of the art of studying interspecies interactions and spatial organization of multispecies communities, aiming to support theoretical and practical arguments for further advancement of this field....

  12. Evidence for the emergence of new rice types of interspecific hybrid origin in West African farmers' fields.

    Directory of Open Access Journals (Sweden)

    Edwin Nuijten

    2009-10-01

    Full Text Available In West Africa two rice species (Oryza glaberrima Steud. and Oryza sativa L. co-exist. Although originally it was thought that interspecific hybridization is impossible without biotechnological methods, progenies of hybridization appear to occur in farmer fields. AFLP analysis was used to assess genetic diversity in West Africa (including the countries The Gambia, Senegal, Guinea Bissau, Guinea Conakry, Sierra Leone, Ghana and Togo using 315 rice samples morphologically classified prior to analysis. We show evidence for farmer interspecific hybrids of African and Asian rice, resulting in a group of novel genotypes, and identify possible mechanisms for in-field hybridization. Spontaneous back-crossing events play a crucial role, resulting in different groups of genetic diversity in different regions developed by natural and cultural selection, often under adverse conditions. These new groups of genotypes may have potential relevance for exploitation by plant breeders. Future advances in crop development could be achieved through co-operation between scientists and marginalized farmer groups in order to address challenges of rapid adaptation in a world of increasing socio-political and climatic uncertainty.

  13. Rin4 causes hybrid necrosis and race-specific resistance in an interspecific lettuce hybrid.

    Science.gov (United States)

    Jeuken, Marieke J W; Zhang, Ningwen W; McHale, Leah K; Pelgrom, Koen; den Boer, Erik; Lindhout, Pim; Michelmore, Richard W; Visser, Richard G F; Niks, Rients E

    2009-10-01

    Some inter- and intraspecific crosses may result in reduced viability or sterility in the offspring, often due to genetic incompatibilities resulting from interactions between two or more loci. Hybrid necrosis is a postzygotic genetic incompatibility that is phenotypically manifested as necrotic lesions on the plant. We observed hybrid necrosis in interspecific lettuce (Lactuca sativa and Lactuca saligna) hybrids that correlated with resistance to downy mildew. Segregation analysis revealed a specific allelic combination at two interacting loci to be responsible. The allelic interaction had two consequences: (1) a quantitative temperature-dependent autoimmunity reaction leading to necrotic lesions, lethality, and quantitative resistance to an otherwise virulent race of Bremia lactucae; and (2) a qualitative temperature-independent race-specific resistance to an avirulent race of B. lactucae. We demonstrated by transient expression and silencing experiments that one of the two interacting genes was Rin4. In Arabidopsis thaliana, RIN4 is known to interact with multiple R gene products, and their interactions result in hypersensitive resistance to Pseudomonas syringae. Site-directed mutation studies on the necrosis-eliciting allele of Rin4 in lettuce showed that three residues were critical for hybrid necrosis.

  14. Genetic analysis of Vitis interspecific hybrids occurring in vineyards of the Czech Republic

    International Nuclear Information System (INIS)

    Jana, R.; Andrea, S.; Radek, S.; Baranek, M.

    2016-01-01

    SSR analysis of 18 unknown uncultured Vitis genotypes planted in an area mostly dedicated to viticulture in the Czech Republic was performed in this work. The aim of this study was to identify analysed samples by comparing their SSR profiles with described standards and classify their mutual relationships based on their distribution in obtained dendrogram. Results show that 50 percent of unknown genotypes belongs to old American interspecific cultivar Noah and 11 percent belong to another old American cultivar Isabella. The rest of analysed genotypes remain unidentified, but three of them suggest relatedness with Noah cultivar, one genotype shows relatednessto Isabella cultivar. From practical point of view the most interesting ones are three genotypes, which were clearly clustered with the genotypes of cultural varities (botanically V. vinifera L.) used as standard. Based on this it is then possible to assume that those genotypes probably originated from crossing of non-V. vinifera genotype specimen with unknown cultural variety. Potential importance of analysed hybrids for further investigation and breeding, especialy in an eco-friendly viticulture, is also discussed. (author)

  15. Perceived Barriers and Facilitators to Integrating HIV Prevention and Treatment with Cross-Sex Hormone Therapy for Transgender Women in Lima, Peru.

    Science.gov (United States)

    Reisner, Sari L; Perez-Brumer, Amaya G; McLean, Sarah A; Lama, Javier R; Silva-Santisteban, Alfonso; Huerta, Leyla; Sanchez, Jorge; Clark, Jesse L; Mimiaga, Matthew J; Mayer, Kenneth H

    2017-12-01

    Transgender women (TW) represent a vulnerable population at increased risk for HIV infection in Peru. A mixed-methods study with 48 TW and 19 healthcare professionals was conducted between January and February 2015 to explore barriers and facilitators to implementing a model of care that integrates HIV services with gender-affirmative medical care (i.e., hormone therapy) in Lima, Peru. Perceived acceptability of the integrated care model was high among TW and healthcare professionals alike. Barriers included stigma, lack of provider training or Peruvian guidelines regarding optimal TW care, and service delivery obstacles (e.g., legal documents, spatial placement of clinics, hours of operation). The hiring of TW staff was identified as a key facilitator for engagement in health care. Working in partnership with local TW and healthcare provider organizations is critical to overcoming existing barriers to successful implementation of an integrated HIV services and gender-affirmative medical care model for this key population in Peru.

  16. Implementing visual cervical cancer screening in Senegal: a cross-sectional study of risk factors and prevalence highlighting service utilization barriers

    Directory of Open Access Journals (Sweden)

    Dykens JA

    2017-01-01

    Full Text Available J Andrew Dykens,1–4 Annē M Linn,5,6 Tracy Irwin,7 Karen E Peters,8 Maria Pyra,8 Fatoumata Traoré,9 Mariama Touré Diarra,9,☪ Memoona Hasnain,1,10 Katie Wallner,11 Patrick Linn,11 Youssoupha Ndiaye12 1Department of Family Medicine, College of Medicine, 2Center for Global Health, 3Institute for Health Research and Policy, 4Cancer Center, Hospital and Health Sciences System, University of Illinois at Chicago, IL, USA; 5Master’s International Graduate School Program, Peace Corps, Dakar, Senegal; 6Rutgers School of Nursing, Newark, NJ, 7Department of Obstetrics and Gynecology, 8School of Public Health, University of Illinois at Chicago, IL, USA; 9Regional Ministry of Health and Social Affairs, Kédougou, Senegal; 10Foundation for Advancement of International Medical Education and Research, Philadelphia, PA, USA; 11Peace Corps, Dakar, 12Regional Ministry of Health and Social Affairs, Sédhiou, Senegal ☪Mariama Touré Diarra passed away on March 21, 2015 Background: Senegal ranks 15th in the world in incidence of cervical cancer, the number one cause of cancer mortality among women in this country. The estimated participation rate for cervical cancer screening throughout Senegal is very low (6.9% of women 18–69 years old, especially in rural areas and among older age groups (only 1.9% of women above the age of 40 years. There are no reliable estimates of the prevalence of cervical dysplasia or risk factors for cervical dysplasia specific to rural Senegal. The goals of this study were to estimate the prevalence of cervical dysplasia in a rural region using visual inspection of the cervix with acetic acid (VIA and to assess risk factors for cervical cancer control. Patients and methods: We conducted a cross-sectional study in which we randomly selected 38 villages across the Kédougou region using a three-stage clustering process. Between October 2013 and March 2014, we collected VIA screening results for women aged 30–50 years and

  17. Development and Meiosis of Three Interspecific Hybrids with Cultivated Barley (Hordeum vulgare L.)

    DEFF Research Database (Denmark)

    Von Bothmer, R.; Flink, J.; Linde-Laursen, Ib

    1986-01-01

    The development and meiosis of three interspecific hybrids between cultivated barley (Hordeum vulgare L.) and H. secalinum Schreb., H. tetraploidum Covas, and H. parodii Covas, respectively, were studied. All three hybrid combinations developed very slowly vegetatively. Meiosis of the hybrids...

  18. Cell-penetrating anti-GFAP VHH and corresponding fluorescent fusion protein VHH-GFP spontaneously cross the blood-brain barrier and specifically recognize astrocytes: application to brain imaging.

    Science.gov (United States)

    Li, Tengfei; Bourgeois, Jean-Pierre; Celli, Susanna; Glacial, Fabienne; Le Sourd, Anne-Marie; Mecheri, Salah; Weksler, Babette; Romero, Ignacio; Couraud, Pierre-Olivier; Rougeon, François; Lafaye, Pierre

    2012-10-01

    Antibodies normally do not cross the blood-brain barrier (BBB) and cannot bind an intracellular cerebral antigen. We demonstrate here for the first time that a new class of antibodies can cross the BBB without treatment. Camelids produce native homodimeric heavy-chain antibodies, the paratope being composed of a single-variable domain called VHH. Here, we used recombinant VHH directed against human glial fibrillary acidic protein (GFAP), a specific marker of astrocytes. Only basic VHHs (e.g., pI=9.4) were able to cross the BBB in vitro (7.8 vs. 0% for VHH with pI=7.7). By intracarotid and intravenous injections into live mice, we showed that these basic VHHs are able to cross the BBB in vivo, diffuse into the brain tissue, penetrate into astrocytes, and specifically label GFAP. To analyze their ability to be used as a specific transporter, we then expressed a recombinant fusion protein VHH-green fluorescent protein (GFP). These "fluobodies" specifically labeled GFAP on murine brain sections, and a basic variant (pI=9.3) of the fusion protein VHH-GFP was able to cross the BBB and to label astrocytes in vivo. The potential of VHHs as diagnostic or therapeutic agents in the central nervous system now deserves attention.

  19. Interspecific studies of circadian genes period and timeless in Drosophila.

    Science.gov (United States)

    Noreen, Shumaila; Pegoraro, Mirko; Nouroz, Faisal; Tauber, Eran; Kyriacou, Charalambos P

    2018-03-30

    The level of rescue of clock function in genetically arrhythmic Drosophila melanogaster hosts using interspecific clock gene transformation was used to study the putative intermolecular coevolution between interacting clock proteins. Among them PER and TIM are the two important negative regulators of the circadian clock feedback loop. We transformed either the D. pseudoobscura per or tim transgenes into the corresponding arrhythmic D. melanogaster mutant (per01 or tim01) and observed >50% rhythmicity but the period of activity rhythm was either longer (D. pseudoobscura-per) or shorter than 24 h (D. pseudoobscura-tim) compared to controls. By introducing both transgenes simultaneously into double mutants, we observed that the period of the activity rhythm was rescued by the pair of hemizygous transgenes (~24 h). These flies also showed a more optimal level of temperature compensation for the period. Under LD 12:12 these flies have a D. pseudoobscura like activity profile with the absence of morning anticipation as well as a very prominent earlier evening peak of activity rhythm. These observation are consistent with the view that TIM and PER form a heterospecific coevolved module at least for the circadian period of activity rhythms. However the strength of rhythmicity was reduced by having both transgenes present, so while evidence for a coevolution between PER and TIM is observed for some characters it is not for others. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  20. Interspecific bacterial interactions are reflected in multispecies biofilm spatial organization

    Directory of Open Access Journals (Sweden)

    Wenzheng Liu

    2016-08-01

    Full Text Available Interspecies interactions are essential for the persistence and development of any kind of complex community, and microbial biofilms are no exception. Multispecies biofilms are structured and spatially defined communities that have received much attention due to their omnipresence in natural environments. Species residing in these complex bacterial communities usually interact both intra- and interspecifically. Such interactions are considered to not only be fundamental in shaping overall biomass and the spatial distribution of cells residing in multispecies biofilms, but also to result in coordinated regulation of gene expression in the different species present. These communal interactions often lead to emergent properties in biofilms, such as enhanced tolerance against antibiotics, host immune responses and other stresses, which have been shown to provide benefits to all biofilm members not only the enabling sub-populations. However, the specific molecular mechanisms of cellular processes affecting spatial organization, and vice versa, are poorly understood and very complex to unravel. Therefore, detailed description of the spatial organization of individual bacterial cells in multispecies communities can be an alternative strategy to reveal the nature of interspecies interactions of constituent species. Closing the gap between visual observation and biological processes may become crucial for resolving biofilm related problems, which is of utmost importance to environmental, industrial, and clinical implications. This review briefly presents the state of the art of studying interspecies interactions and spatial organization of multispecies communities, aiming to support theoretical and practical arguments for further advancement of this field.

  1. [Interspecific interaction between Moina mongolica and Brachionus plicatilis].

    Science.gov (United States)

    Chen, Taoying; Wang, Yan; Huang, Changzhi; Hu, Shiheng; Zhang, Jun

    2004-07-01

    In a laboratory experiment, Moina mongolica and Brachionus plicatilis were polycultured at four relatively inoculating densities, i.e., 0.06/0.30, 0.10/0.30, 0.30/0.30 and 0.60/0.30 (ind x ml(-1)/ind x ml(-1)), while M. mongolica monocultured at 0.06, 0.10, 0.30 and 0.60 ind x ml(-1) and B. plicatilis at 0.30 ind x ml(-1) were used as the control. Interspecific interference did exist between M. mongolica and B. plicatilis when these two species coexisted in a microcosm. In the polycultured microcosms, depressed population density of M. mongolica resulted from the coexistence of B. plicatilis, and M. mongolica maintained at extremely low density. In opposite, M. mongolica had negligibly negative influence on the population of B. plicatilis. Further experiment showed that the mortality of M. mongolica deprived of food for 120 h was 100%, while 90% of B. plicatilis survived after 144 h of food deprivation. The relatively strong capacity of B. plicatilis in tolerating starvation may be one of the important reasons for it wins the competition against M. mongolica.

  2. Motorboat noise disrupts co-operative interspecific interactions.

    Science.gov (United States)

    Nedelec, Sophie L; Mills, Suzanne C; Radford, Andrew N; Beldade, Ricardo; Simpson, Stephen D; Nedelec, Brendan; Côté, Isabelle M

    2017-08-01

    Human-made noise is contributing increasingly to ocean soundscapes. Its physical, physiological and behavioural effects on marine organisms are potentially widespread, but our understanding remains largely limited to intraspecific impacts. Here, we examine how motorboats affect an interspecific cleaning mutualism critical for coral reef fish health, abundance and diversity. We conducted in situ observations of cleaning interactions between bluestreak cleaner wrasses (Labroides dimidiatus) and their fish clients before, during and after repeated, standardised approaches with motorboats. Cleaners inspected clients for longer and were significantly less cooperative during exposure to boat noise, and while motorboat disturbance appeared to have little effect on client behaviour, as evidenced by consistency of visit rates, clientele composition, and use of cleaning incitation signals, clients did not retaliate as expected (i.e., by chasing) in response to increased cheating by cleaners. Our results are consistent with the idea of cognitive impairments due to distraction by both parties. Alternatively, cleaners might be taking advantage of distracted clients to reduce their service quality. To more fully understand the importance of these findings for conservation and management, further studies should elucidate whether the efficacy of ectoparasite removal by cleaners is affected and explore the potential for habituation to boat noise in busy areas.

  3. Interspecific social networks promote information transmission in wild songbirds.

    Science.gov (United States)

    Farine, Damien R; Aplin, Lucy M; Sheldon, Ben C; Hoppitt, William

    2015-03-22

    Understanding the functional links between social structure and population processes is a central aim of evolutionary ecology. Multiple types of interactions can be represented by networks drawn for the same population, such as kinship, dominance or affiliative networks, but the relative importance of alternative networks in modulating population processes may not be clear. We illustrate this problem, and a solution, by developing a framework for testing the importance of different types of association in facilitating the transmission of information. We apply this framework to experimental data from wild songbirds that form mixed-species flocks, recording the arrival (patch discovery) of individuals to novel foraging sites. We tested whether intraspecific and interspecific social networks predicted the spread of information about novel food sites, and found that both contributed to transmission. The likelihood of acquiring information per unit of connection to knowledgeable individuals increased 22-fold for conspecifics, and 12-fold for heterospecifics. We also found that species varied in how much information they produced, suggesting that some species play a keystone role in winter foraging flocks. More generally, these analyses demonstrate that this method provides a powerful approach, using social networks to quantify the relative transmission rates across different social relationships.

  4. Interspecific competition between alien and native congeneric species

    Science.gov (United States)

    Garcia-Serrano, H.; Sans, F. X.; Escarré, J.

    2007-01-01

    A good way to check hypotheses explaining the invasion of ecosystems by exotic plants is to compare alien and native congeneric species. To test the hypothesis that invasive alien plants are more competitive than natives, we designed a replacement series experiment to evaluate interspecific competition between three Senecio species representing the same bushy life form: two alien species ( S. inaequidens and S. pterophorus, both from South Africa) and a native species from the south-east of the Iberian Peninsula and Maghreb ( S. malacitanus). While S. inaequidens is widespread throughout western Europe and is expanding towards the south of Spanish-French border, the geographical distribution of the recently introduced S. pterophorus is still limited to north-eastern Spain. Plants from each species were grown in pure and in mixed cultures with one of their congeners, and water availability was manipulated to evaluate the effects of water stress on competitive abilities. Our results show that the alien S. inaequidens is the most competitive species for all water conditions. The native S. malacitanus is more competitive that the alien S. pterophorus in water stress conditions, but this situation is reversed when water availability is not limiting.

  5. Coupled-channel calculation for cross section of fusion and barrier distribution of {}^{16,17,18}O + {}^{16}O reactions

    Science.gov (United States)

    Fereidonnejad, R.; Sadeghi, H.; Ghambari, M.

    2018-03-01

    In this work, the effect of multi-phonon excitation on heavy-ion fusion reactions has been studied and fusion barrier distributions of energy intervals near and below the Coulomb barrier have been studied for 16,17,18O + 16O reactions. The structure and deformation of nuclear projectiles have been studied. Given the adaptation of computations to experimental data, our calculations predict the behavior of reactions in intervals of energy in which experimental measurements are not available. In addition the S-factor for these reactions has been calculated. The results showed that the structure and deformation of a nuclear projectile are important factors. The S-factor, obtained in the coupled-channel calculations for the {}^{16}O + {}^{16}O, {}^{17}O +{}^{16}O and {}^{18}O +{}^{16}O reactions, showed good agreement with the experimental data and had a maximum value at an energy near 5, 4.5 and 4 MeV, respectively.

  6. Interspecific variations in the gastrointestinal microbiota in penguins.

    Science.gov (United States)

    Dewar, Meagan L; Arnould, John P Y; Dann, Peter; Trathan, Phil; Groscolas, Rene; Smith, Stuart

    2013-02-01

    Despite the enormous amount of data available on the importance of the gastrointestinal (GI) microbiota in vertebrate (especially mammals), information on the GI microbiota of seabirds remains incomplete. As with many seabirds, penguins have a unique digestive physiology that enables them to store large reserves of adipose tissue, protein, and lipids. This study used quantitative real-time polymerase chain reaction (qPCR) and 16S rRNA gene pyrosequencing to characterize the interspecific variations of the GI microbiota of four penguin species: the king, gentoo, macaroni, and little penguin. The qPCR results indicated that there were significant differences in the abundance of the major phyla Firmicutes, Bacteroides, Actinobacteria, and Proteobacteria. A total of 132,340, 18,336, 6324, and 4826 near full-length 16S rRNA gene sequences were amplified from fecal samples collected from king, gentoo, macaroni, and little penguins, respectively. A total of 13 phyla were identified with Firmicutes, Bacteroidetes, Proteobacteria, and Fusobacteria dominating the composition; however, there were major differences in the relative abundance of the phyla. In addition, this study documented the presence of known human pathogens, such as Campylobacter, Helicobacter, Prevotella, Veillonella, Erysipelotrichaceae, Neisseria, and Mycoplasma. However, their role in disease in penguins remains unknown. To our knowledge, this is the first study to provide an in-depth investigation of the GI microbiota of penguins. © 2013 The Authors. Published by Blackwell Publishing Ltd. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

  7. Interspecific nest parasitism by chukar on greater sage-grouse

    Science.gov (United States)

    Fearon, Michelle L.; Coates, Peter S.

    2014-01-01

    Nest parasitism occurs when a female bird lays eggs in the nest of another and the host incubates the eggs and may provide some form of parental care for the offspring (Lyon and Eadie 1991). Precocial birds (e.g., Galliformes and Anseriformes) are typically facultative nest parasites of both their own and other species (Lyon and Eadie 1991). This behavior increases a female’s reproductive success when she parasitizes other nests while simultaneously raising her own offspring. Both interspecific and conspecific nest parasitism have been well documented in several families of the order Galliformes, particularly the Phasianidae (Lyon and Eadie 1991, Geffen and Yom-Tov 2001, Krakauer and Kimball 2009). The Chukar (Alectoris chukar) has been widely introduced as a game bird to western North America from Eurasia and is now well established within the Great Basin from northeastern California east to Utah and north to Idaho and Oregon (Christensen 1996). Over much of this range the Chukar occurs with other phasianids, including the native Greater Sage-Grouse (Centrocercus urophasianus), within sagebrush (Artemisia spp.) steppe (Christensen 1996, Schroeder et al. 1999, Connelly et al. 2000). Chukar typically exploit a broader range of habitats than do sage-grouse, but both species use the same species of sagebrush and other shrubs for nesting cover (Christensen 1996, Schroeder et al. 1999). Chukar are known to parasitize nests of other individuals of their own species (Geffen and Yom-Tov 2001), but we are unaware of reported evidence that Chukar may parasitize nests of sage-grouse. Here we describe a case of a Chukar parasitizing a sage-grouse nest in the sagebrush steppe of western Nevada.

  8. A cross sectional observational study of research activity of allied health teams: is there a link with self-reported success, motivators and barriers to undertaking research?

    Science.gov (United States)

    Wenke, Rachel J; Mickan, Sharon; Bisset, Leanne

    2017-02-06

    Team-based approaches to research capacity building (RCB) may be an efficient means to promote allied health research participation and activity. In order to tailor such interventions, a clearer understanding of current patterns of research participation within allied health teams is needed. Different self-report measures exist which evaluate a team's research capacity and participation, as well as associated barriers and motivators. However, it remains unclear how such measures are associated with a team's actual research activity (e.g., journal publications, funding received). In response, this observational study aimed to identify the research activity, self-reported success, and motivations and barriers to undertaking research of eight allied health professional (AHP) teams and to explore whether any relationships exist between the self-reported measures and actual research activity within each team. A total of 95 AHPs from eight teams completed the research capacity and culture survey to evaluate team success, barriers and motivators to undertaking research, and an audit of research activity from January 2013 to August 2014 was undertaken within each team. Kendell's correlation coefficients were used to determine the association between research activity (i.e., number of journal publications, ethically approved projects and funding received) and the self-reported measures. Seven out of eight teams rated their teams as having average success in research and demonstrated some form of research activity including at least two ethically approved projects. Research activity varied between teams, with funding received ranging from $0 to over $100,000, and half the teams not producing any journal publications. Team motivators demonstrated a stronger association with research activity compared to barriers, with the motivator "enhancing team credibility" being significantly associated with funding received. No significant association between self-reported research

  9. Interspecific interactions in phytophagous insects revisited: a quantitative assessment of competition theory.

    Science.gov (United States)

    Kaplan, Ian; Denno, Robert F

    2007-10-01

    The importance of interspecific competition is a highly controversial and unresolved issue for community ecology in general, and for phytophagous insects in particular. Recent advancements, however, in our understanding of indirect (plant- and enemy-mediated) interactions challenge the historical paradigms of competition. Thus, in the context of this rapidly developing field, we re-evaluate the evidence for interspecific competition in phytophagous insects using a meta-analysis of published studies. Our analysis is specifically designed to test the assumptions underlying traditional competition theory, namely that competitive interactions are symmetrical, necessitate spatial and temporal co-occurrence, and increase in intensity as the density, phylogenetic similarity, and niche overlap of competing species increase. Despite finding frequent evidence for competition, we found very little evidence that plant-feeding insects conform to theoretical predictions for interspecific competition. Interactions were highly asymmetrical, similar in magnitude within vs. between feeding guilds (chewers vs. sap-feeders), and were unaffected by the quantity of resources removed (% defoliation). There was mixed support for the effects of phylogeny, spatial/temporal separation, and the relative strength of intra- vs. interspecific competition. Clearly, a new paradigm that accounts for indirect interactions and facilitation is required to describe how interspecific competition contributes to the organization of phytophagous insect communities, and perhaps to other plant and animal communities as well.

  10. Support or Barrier?

    DEFF Research Database (Denmark)

    Sanden, Guro Refsum; Lønsmann, Dorte

    This study offers a critical look at how corporate-level language management influences front-line language practices among employees in three multinational corporations (MNCs) headquartered in Scandinavia. Based on interview and document data, we examine, firstly, what front-line practices...... employees use to cross language boundaries in their everyday work, and, secondly, how these practices relate to top-down language management in the case companies. Our findings show that employees are often dependent on ad hoc and informal solutions in cross- language situations, which leads us...... to a discussion of how a company’s language policy may be seen as both support and a barrier....

  11. Tiger, Bengal and Domestic Cat Embryos Produced by Homospecific and Interspecific Zona-Free Nuclear Transfer.

    Science.gov (United States)

    Moro, L N; Jarazo, J; Buemo, C; Hiriart, M I; Sestelo, A; Salamone, D F

    2015-10-01

    The aim of this study was to evaluate three different cloning strategies in the domestic cat (Felis silvestris) and to use the most efficient to generate wild felid embryos by interspecific cloning (iSCNT) using Bengal (a hybrid formed by the cross of Felis silvestris and Prionailurus bengalensis) and tiger (Panthera tigris) donor cells. In experiment 1, zona-free (ZP-free) cloning resulted in higher fusion and expanded blastocyst rates with respect to zona included cloning techniques that involved fusion or injection of the donor cell. In experiment 2, ZP-free iSCNT and embryo aggregation (2X) were assessed. Division velocity and blastocyst rates were increased by embryo aggregation in the three species. Despite fewer tiger embryos than Bengal and cat embryos reached the blastocyst stage, Tiger 2X group increased the percentage of blastocysts with respect to Tiger 1X group (3.2% vs 12.1%, respectively). Moreover, blastocyst cell number was almost duplicated in aggregated embryos with respect to non-aggregated ones within Bengal and tiger groups (278.3 ± 61.9 vs 516.8 ± 103.6 for Bengal 1X and Bengal 2X groups, respectively; 41 vs 220 ± 60 for Tiger 1X and Tiger 2X groups, respectively). OCT4 analysis also revealed that tiger blastocysts had higher proportion of OCT4-positive cells with respect to Bengal blastocysts and cat intracytoplasmic sperm injection blastocysts. In conclusion, ZP-free cloning has improved the quality of cat embryos with respect to the other cloning techniques evaluated and was successfully applied in iSCNT complemented with embryo aggregation. © 2015 Blackwell Verlag GmbH.

  12. Designing and creating Saccharomyces interspecific hybrids for improved, industry relevant, phenotypes.

    Science.gov (United States)

    Bellon, Jennifer R; Yang, Fei; Day, Martin P; Inglis, Debra L; Chambers, Paul J

    2015-10-01

    To remain competitive in increasingly overcrowded markets, yeast strain development programmes are crucial for fermentation-based food and beverage industries. In a winemaking context, there are many yeast phenotypes that stand to be improved. For example, winemakers endeavouring to produce sweet dessert wines wrestle with fermentation challenges particular to fermenting high-sugar juices, which can lead to elevated volatile acidity levels and extended fermentation times. In the current study, we used natural yeast breeding techniques to generate Saccharomyces spp. interspecific hybrids as a non-genetically modified (GM) strategy to introduce targeted improvements in important, wine-relevant traits. The hybrids were generated by mating a robust wine strain of Saccharomyces cerevisiae with a wine isolate of Saccharomyces bayanus, a species previously reported to produce wines with low concentrations of acetic acid. Two hybrids generated from the cross showed robust fermentation properties in high-sugar grape juice and produced botrytised Riesling wines with much lower concentrations of acetic acid relative to the industrial wine yeast parent. The hybrids also displayed suitability for icewine production when bench-marked against an industry standard icewine yeast, by delivering icewines with lower levels of acetic acid. Additionally, the hybrid yeast produced wines with novel aroma and flavour profiles and established that choice of yeast strain impacts on wine colour. These new hybrid yeasts display the desired targeted fermentation phenotypes from both parents, robust fermentation in high-sugar juice and the production of wines with low volatile acidity, thus establishing their suitability for wine styles that are traditionally troubled by excessive volatile acidity levels.

  13. Barriers to the implementation of programs for the prevention of mother-to-child transmission of HIV: A cross-sectional survey in rural and urban Uganda

    Directory of Open Access Journals (Sweden)

    Bajunirwe Francis

    2005-10-01

    Full Text Available Abstract Background Implementation of programs for the prevention of mother-to-child transmission (PMTCT of HIV faces a variety of barriers and challenges. The assessment of these challenges has generally been conducted in large urban health facilities. As programs expand into rural areas, the potential barriers that may be encountered there also need to be assessed. This study examines potential barriers that might affect the acceptability of interventions for PMTCT in rural and urban settings. Results Four hundred and four women at a large urban hospital and three rural clinics that had recently started implementing PMTCT were interviewed. Level of knowledge of MTCT and preference for rapid HIV testing were equally high in both areas, but rural women had a higher tendency to think that they should consult their husbands before testing, with borderline statistical significance (72% vs. 64% p = 0.09. Health facility-based deliveries were significantly lower among mothers in rural areas compared to those in the urban setting. Overall, significant predictors of willingness to test for HIV were post-primary education (OR = 3.1 95% CI 1.2, 7.7 and knowledge about rapid HIV tests (OR = 1.8, 95% CI 1.01, 3.4. The strongest predictor of willingness to accept an HIV test was the woman's perception that her husband would approve of her testing for HIV. Women who thought their husbands would approve were almost six times more likely to report a willingness to be tested compared to those who thought their husbands would not approve (OR = 5.6, 95% CI 2.8, 11.2. Conclusion Lessons learned in large urban hospitals can be generalized to rural facilities, but the lower proportion of facility-based deliveries in rural areas needs to be addressed. Same-day results are likely to ensure high uptake of HIV testing services but male spousal involvement should be considered, particularly for rural areas. Universal Primary Education will support the success of PMTCT

  14. Interspecific competition influences the organization of a diverse sessile insect community

    Science.gov (United States)

    Cornelissen, Tatiana; de Carvalho Guimarães, Carla Daniele; Rodrigues Viana, João Paulo; Silva, Bárbara

    2013-10-01

    Interspecific competition has played a major role in determining the effects of species interactions in terrestrial communities and the perception of its role on shaping population dynamics and community structure has changed throughout the years. In this study, we evaluated the existence of interspecific competition in the herbivore community of the dioecious plant Baccharis pseudomyriocephala (Asteraceae), which holds a diverse community of gall-forming insects. Sixty plants were studied and gall richness and abundance among plants were evaluated. To address whether a plant already occupied by a gall species is preferred or avoided by another gall species, null models were used for all 60 plants combined and for male and female plants separately. Our results have shown that the 11 species of gall-formers found on B. pseudomyriocephala co-occur less than expected by chance alone, indicating that interspecific competition might be an important force structuring the insect community in this tropical host plant, regardless of plant gender.

  15. [Effect of habitat and interspecific competition on Apis cerana cerana colony distribution].

    Science.gov (United States)

    Yu, Linsheng; Han, Shengming

    2003-04-01

    Habitat change and interspecific competition were the main factors affecting, Apis cerana cerana colony distribution among Wannan and Wanxi Dabie mountainous areas, Jianghuai area and Huaibei plain. Wannan and Wanxi Dabie mountainous areas were the ideal places for Apis cerana cerana' habitation and propogation, in which, there were integrated natural vegetation, fine ecological condition, abundant nectariferous plants, and Apis cerana cerana had large colony size, wide distribution, high density, no disturbances of natural mating, and was dominant interspecific competition. In Jianghuai area and Huaibei plain, there were small covering of natural vegetation, different degree of degradation of ecological balance, few kinds of nectariferous plants with almost the same blooming periods, natural mating perturbed by Apis mellifera ligustica for Apis cerana cerana, and which was inferior in interspecific competition, colony size sharply decreased, distribution area reduced, and density cut down to a great extent. In Huaibei plain, the negative factors were more conspicuous.

  16. Influence of Temperature on Intra- and Interspecific Resource Utilization within a Community of Lepidopteran Maize Stemborers.

    Science.gov (United States)

    Ntiri, Eric Siaw; Calatayud, Paul-Andre; Van Den Berg, Johnnie; Schulthess, Fritz; Le Ru, Bruno Pierre

    2016-01-01

    Competition or facilitation characterises intra- and interspecific interactions within communities of species that utilize the same resources. Temperature is an important factor influencing those interactions and eventual outcomes. The noctuid stemborers, Busseola fusca and Sesamia calamistis and the crambid Chilo partellus attack maize in sub-Saharan Africa. They often occur as a community of interacting species in the same field and plant at all elevations. The influence of temperature on the intra- and interspecific interactions among larvae of these species, was studied using potted maize plants exposed to varying temperatures in a greenhouse and artificial stems kept at different constant temperatures (15°C, 20°C, 25°C and 30°C) in an incubator. The experiments involved single- and multi-species infestation treatments. Survival and relative growth rates of each species were assessed. Both intra- and interspecific competitions were observed among all three species. Interspecific competition was stronger between the noctuids and the crambid than between the two noctuids. Temperature affected both survival and relative growth rates of the three species. Particularly at high temperatures, C. partellus was superior in interspecific interactions shown by higher larval survival and relative growth rates. In contrast, low temperatures favoured survival of B. fusca and S. calamistis but affected the relative growth rates of all three species. Survival and relative growth rates of B. fusca and S. calamistis in interspecific interactions did not differ significantly across temperatures. Temperature increase caused by future climate change is likely to confer an advantage on C. partellus over the noctuids in the utilization of resources (crops).

  17. Influence of Temperature on Intra- and Interspecific Resource Utilization within a Community of Lepidopteran Maize Stemborers.

    Directory of Open Access Journals (Sweden)

    Eric Siaw Ntiri

    Full Text Available Competition or facilitation characterises intra- and interspecific interactions within communities of species that utilize the same resources. Temperature is an important factor influencing those interactions and eventual outcomes. The noctuid stemborers, Busseola fusca and Sesamia calamistis and the crambid Chilo partellus attack maize in sub-Saharan Africa. They often occur as a community of interacting species in the same field and plant at all elevations. The influence of temperature on the intra- and interspecific interactions among larvae of these species, was studied using potted maize plants exposed to varying temperatures in a greenhouse and artificial stems kept at different constant temperatures (15°C, 20°C, 25°C and 30°C in an incubator. The experiments involved single- and multi-species infestation treatments. Survival and relative growth rates of each species were assessed. Both intra- and interspecific competitions were observed among all three species. Interspecific competition was stronger between the noctuids and the crambid than between the two noctuids. Temperature affected both survival and relative growth rates of the three species. Particularly at high temperatures, C. partellus was superior in interspecific interactions shown by higher larval survival and relative growth rates. In contrast, low temperatures favoured survival of B. fusca and S. calamistis but affected the relative growth rates of all three species. Survival and relative growth rates of B. fusca and S. calamistis in interspecific interactions did not differ significantly across temperatures. Temperature increase caused by future climate change is likely to confer an advantage on C. partellus over the noctuids in the utilization of resources (crops.

  18. Susceptibility of parent and interspecific Fl hybrid pine trees to tip moth damage in a coastal North Carolina planting

    Science.gov (United States)

    Maxine T. Highsmith; John Frampton; David 0' Malley; James Richmond; Martesa Webb

    2001-01-01

    Tip moth damage arnong families of parent pine species and their interspecific F1 hybrids was quantitatively assessed in a coastal planting in North Carolina. Three slash pine (Pinus elliotti var. elliotti Engelm.), two loblolly pine (Pinus taeda L.), and four interspecific F1 hybrid pine families were used. The...

  19. Triploid production from interspecific crosses of two diploid perennial Helianthus with cultivated sunflower

    Science.gov (United States)

    Wild Helianthus species are a valuable genetic source for the improvement of cultivated sunflower. We report the discovery and characterization of a unique high frequency production of triploids when cultivated sunflower was pollinated by specific accessions of diploid Helianthus nuttallii T. &. G. ...

  20. Molecular mapping of resistance to blight in an interspecific cross in the genus Castanea

    Science.gov (United States)

    Thomas L. Kubisiak; F.V. Hebard; C. Dana Nelson; Jiansu Zhang; R. Bernatzky; H. Huang; S.L. Anagnostakis; R.L. Doudrick

    1997-01-01

    A three-generation American chestnut x Chinese chestnut pedigree was used to construct a genetic linkage map for chestnut and to investigate the control of resistance to Endothia parasitica (chestnut blight fungus). DNA genotypes for 241 polymorphic markers (eight isozymes, 17 restriction fragment length polymorphisms [RFLPs], and 216 random...

  1. Knowledge, attitude, practice and barriers on vaccination against human papillomavirus infection: a cross-sectional study among primary care physicians in Hong Kong.

    Science.gov (United States)

    Wong, Martin C S; Lee, Albert; Ngai, Karry L K; Chor, Josette C Y; Chan, Paul K S

    2013-01-01

    This study explored the knowledge, attitude, practice and barriers to prescribe human papillomavirus (HPV) vaccines among private primary care physicians in Hong Kong. A self-administered questionnaire survey was conducted by sending letters to doctors who had joined a vaccination program for school girls. From 720 surveys sent, 444 (61.7%) completed questionnaires were returned and analyzed. For knowledge, few responded to questions accurately on the prevalence of cervical HPV (27.9%) and genital wart infection (13.1%) among sexually active young women in Hong Kong, and only 44.4% correctly answered the percentage of cervical cancers caused by HPV. For attitude, most agreed that HPV vaccination should be fully paid by the Government (68.3%) as an important public health strategy. Vaccination against HPV was perceived as more important than those for genital herpes (52.2%) and Chlamydia (50.1%) for adolescent health, and the majority selected adolescents aged 12-14 years as the ideal group for vaccination. Gardasil(®) (30.9%) and Cervarix(®) (28.0%) were almost equally preferred. For practice, the factors influencing the choice of vaccine included strength of vaccine protection (61.1%), long-lasting immunity (56.8%) and good antibody response (55.6%). The most significant barriers to prescribe HPV vaccines consisted of parental refusal due to safety concerns (48.2%), and their practice of advising vaccination was mostly affected by local Governmental recommendations (78.7%). A substantial proportion of physicians had recommended HPV vaccines for their female clients/patients aged 18-26 years for protection of cervical cancer (83.8%) or both cervical cancer and genital warts (85.5%). The knowledge on HPV infection was low among physicians in Hong Kong. Prescription of HPV vaccine was hindered by the perceived parental concerns and was mostly relied on Governmental recommendations. Educational initiatives should be targeted towards both physicians and parents, and

  2. Knowledge, attitude, practice and barriers on vaccination against human papillomavirus infection: a cross-sectional study among primary care physicians in Hong Kong.

    Directory of Open Access Journals (Sweden)

    Martin C S Wong

    Full Text Available This study explored the knowledge, attitude, practice and barriers to prescribe human papillomavirus (HPV vaccines among private primary care physicians in Hong Kong. A self-administered questionnaire survey was conducted by sending letters to doctors who had joined a vaccination program for school girls. From 720 surveys sent, 444 (61.7% completed questionnaires were returned and analyzed. For knowledge, few responded to questions accurately on the prevalence of cervical HPV (27.9% and genital wart infection (13.1% among sexually active young women in Hong Kong, and only 44.4% correctly answered the percentage of cervical cancers caused by HPV. For attitude, most agreed that HPV vaccination should be fully paid by the Government (68.3% as an important public health strategy. Vaccination against HPV was perceived as more important than those for genital herpes (52.2% and Chlamydia (50.1% for adolescent health, and the majority selected adolescents aged 12-14 years as the ideal group for vaccination. Gardasil(® (30.9% and Cervarix(® (28.0% were almost equally preferred. For practice, the factors influencing the choice of vaccine included strength of vaccine protection (61.1%, long-lasting immunity (56.8% and good antibody response (55.6%. The most significant barriers to prescribe HPV vaccines consisted of parental refusal due to safety concerns (48.2%, and their practice of advising vaccination was mostly affected by local Governmental recommendations (78.7%. A substantial proportion of physicians had recommended HPV vaccines for their female clients/patients aged 18-26 years for protection of cervical cancer (83.8% or both cervical cancer and genital warts (85.5%. The knowledge on HPV infection was low among physicians in Hong Kong. Prescription of HPV vaccine was hindered by the perceived parental concerns and was mostly relied on Governmental recommendations. Educational initiatives should be targeted towards both physicians and parents

  3. Barrier Systems

    NARCIS (Netherlands)

    Heteren, S. van

    2015-01-01

    Barrier-system dynamics are a function of antecedent topography and substrate lithology, Relative sea-level (RSL) changes, sediment availability and type, climate, vegetation type and cover, and various aero- and hydrodynamic processes during fair-weather conditions and extreme events. Global change

  4. Penetration through the Skin Barrier

    DEFF Research Database (Denmark)

    Nielsen, Jesper Bo; Benfeldt, Eva; Holmgaard, Rikke

    2016-01-01

    The skin is a strong and flexible organ with barrier properties essential for maintaining homeostasis and thereby human life. Characterizing this barrier is the ability to prevent some chemicals from crossing the barrier while allowing others, including medicinal products, to pass at varying rates......-through diffusion cells) as well as in vivo methods (microdialysis and microperfusion). Then follows a discussion with examples of how different characteristics of the skin (age, site and integrity) and of the penetrants (size, solubility, ionization, logPow and vehicles) affect the kinetics of percutaneous...

  5. Combining Ascochyta blight and Botrytis grey mould resistance in chickpea through interspecific hybridization

    Directory of Open Access Journals (Sweden)

    Livinder KAUR

    2013-05-01

    Full Text Available Ascochyta blight (AB caused by Ascochyta rabiei (Pass. Labr. and Botrytis grey mould (BGM caused by Botrytis cinerea (Pers. ex Fr. are important diseases of the aerial plant parts of chickpea in most chickpea growing areas of the world. Although conventional approaches have contributed to reducing disease, the use of new technologies is expected to further reduce losses through these biotic stresses. Reliable screening techniques were developed: ‘field screening technique’ for adult plant screening, ‘cloth chamber technique’ and ‘growth chamber technique’ for the study of races of the pathogen and for segregating generations. Furthermore, the ‘cut twig technique’ for interspecific population for AB and BGM resistance was developed. For introgression of high levels of AB and BGM resistance in cultivated chickpea from wild relatives, accessions of seven annual wild Cicer spp. were evaluated and identified: C. judaicum accessions 185, ILWC 95 and ILWC 61, C. pinnatifidum accessions 188, 199 and ILWC 212 as potential donors. C. pinnatifidum accession188 was crossed with ICCV 96030 and 62 F9 lines resistant to AB and BGM were derived. Of the derived lines, several are being evaluated for agronomic traits and yield parameters while four lines, GL 29029, GL29206, GL29212, GL29081 possessing high degree of resistance were crossed with susceptible high yielding cultivars BG 256 to improve resistance and to undertake molecular studies. Genotyping of F2 populations with SSR markers from the chickpea genome was done to identify markers potentially linked with AB and BGM resistance genes. In preliminary studies, of 120 SSR markers used, six (Ta 2, Ta 110, Ta 139, CaSTMS 7, CaSTMS 24 and Tr 29 were identified with polymorphic bands between resistant derivative lines and the susceptible parent. The study shows that wild species of Cicer are the valuable gene pools of resistance to AB and BGM. The resistant derivative lines generated here can

  6. Organizational barriers associated with the implementation of national essential medicines policy: A cross-sectional study of township hospitals in China.

    Science.gov (United States)

    Yang, Lianping; Liu, Chaojie; Ferrier, J Adamm; Zhang, Xinping

    2015-11-01

    This study identifies potential organizational barriers associated with the implementation of the Chinese National Essential Medicines Policy (NEMP) in rural primary health care institutions. We used a multistage sampling strategy to select 90 township hospitals from six provinces, two from each of eastern, middle, and western China. Data relating to eight core NEMP indicators and institutional characteristics were collected from January to September 2011, using a questionnaire. Prescription-associated indicators were calculated from 9000 outpatient prescriptions selected at random. We categorized the eight NEMP indicators using an exploratory factor analysis, and performed linear regressions to determine the association between the factor scores and institution-level characteristics. The results identified three main factors. Overall, low levels of expenditure of medicines (F1) and poor performance in rational use of medicines (F2) were evident. The availability of medicines (F3) varied significantly across both hospitals and regions. Factor scores had no significant relationship with hospital size (in terms of number of beds and health workers); however, they were associated with revenue and structure of the hospital, patient service load, and support for health workers. Regression analyses showed that public finance per health worker was negatively associated with the availability of medicines (p finance from local governments may reduce medicine stock lines of township hospitals and lead them to seek alternative sources of income, jeopardizing their capacity to meet the needs of local consumers. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Is fatigue after work a barrier for leisure-time physical activity? Cross-sectional study among 10,000 adults from the general working population.

    Science.gov (United States)

    Bláfoss, Rúni; Micheletti, Jéssica K; Sundstrup, Emil; Jakobsen, Markus D; Bay, Hans; Andersen, Lars L

    2018-04-01

    In spite of the many health-related benefits of regular physical activity, fatiguing work may be a barrier to performing leisure-time physical activity. This study investigates the association between work-related fatigue and the duration of low- and high-intensity leisure-time physical activity in workers with sedentary and physically demanding jobs. From the 2010 round of the Danish Work Environment Cohort Study, currently employed wage earners from the general working population ( N=10,427) replied to questions about work-related fatigue (predictor) and duration of low- and high-intensity leisure-time physical activity (outcome). Associations were modelled using general linear models controlling for various confounders. Among workers with physically demanding jobs, higher levels of work-related fatigue were associated with gradually lower levels of leisure-time physical activity - for low, moderate and high levels of work-related fatigue the duration of high-intensity leisure-time physical activity was 133 (95% confidence interval (CI) 127-178), 134 (95% CI 109-160) and 113 (95% CI 86-140) min per week, respectively (trend test pwork-related fatigue in workers with physically demanding jobs. Older workers perform less high-intensity physical activity than younger workers. Workplaces should consider initiatives to allow workers with physically demanding jobs and older workers to perform physical exercise during working hours and thereby increase physical capacity to meet the job demands.

  8. Embryo rescue of crosses between diploid and tetraploid grape ...

    African Journals Online (AJOL)

    ajl yemi

    2011-12-19

    Dec 19, 2011 ... embryo rescue from interspecific hybridization between diploid and tetraploid grape species. Wakana et al. (2003) and Motosugi et al. (2003) studied the formation and developments of hybrid seeds from cross between diploid and tetraploid, and then obtained triploid progenies through embryo rescue.

  9. Acceptance and barriers to access of occupational e-mental health: cross-sectional findings from a health-risk population of employees.

    Science.gov (United States)

    Hennemann, Severin; Witthöft, Michael; Bethge, Matthias; Spanier, Katja; Beutel, Manfred E; Zwerenz, Rüdiger

    2018-04-01

    Occupational e-mental-health (OEMH) may extend existing instruments for preservation or restoration of health and work ability. As a key precondition to efficient implementation, this study examined acceptance and person-centered barriers to potential uptake of OEMH for work-related distress in employees with an elevated risk of early retirement. Within the framework of the "Third German Sociomedical Panel of Employees", 1829 employees with prior sickness absence payments filled out a self-administered questionnaire. Participants had a mean age of 49.93 years (SD = 4.06). 6.2% indicated prior use of eHealth interventions. Potential predictors of acceptance of OEMH were examined based on the "Unified Theory of Acceptance and Use of Technology" (UTAUT) extended by work ability, mental health, eHealth literacy and demographic characteristics. 89.1% (n = 1579) showed low to moderate acceptance (M = 2.20, SD = 1.05, range 1-5). A path analysis revealed significant, positive direct effects of UTAUT predictors on acceptance (performance expectancy: 0.48, SE = 0.02, p acceptance. Model fit was good [χ 2 (7) = 12.91, p = 0.07, RMSEA = 0.02, CFI = 1.00, TLI = 0.99, SRMR = 0.01]. Attitudes towards OEMH are rather disadvantageous in the studied risk group. Implementation of OEMH, therefore, requires a-priori education including promotion of awareness, favorable attitudes regarding efficacy and usability in a collaborative approach.

  10. Market and Policy Barriers to Energy Storage Deployment

    Energy Technology Data Exchange (ETDEWEB)

    Bhatnagar, Dhruv [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Currier, Aileen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hernandez, Jacquelynne [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ma, Ookie [Dept. of Energy (DOE), Washington DC (United States) Office of Energy Efficiency and Renewable Energy; Kirby, Brendan [Consultant

    2013-09-01

    Electric energy storage technologies can provide numerous grid services; there are a number of factors that restrict their current deployment. The most significant barrier to deployment is high capital costs, though several recent deployments indicate that capital costs are decreasing and energy storage may be the preferred economic alternative in certain situations. However, a number of other market and regulatory barriers persist, limiting further deployment. These barriers can be categorized into regulatory barriers, market (economic) barriers, utility and developer business model barriers, cross-cutting barriers and technology barriers.

  11. Information barriers

    International Nuclear Information System (INIS)

    Fuller, J.L.; Wolford, J.

    2001-01-01

    Full text: An information barrier (IB) consists of procedures and technology that prevent the release of sensitive information during a joint inspection of a sensitive nuclear item, and provides confidence that the measurement system into which it has been integrated functions exactly as designed and constructed. Work in the U.S. on radiation detection system information barriers dates back at least to 1990, even though the terminology is more recent. In January 1999 the Joint DoD-DOE Information Barrier Working Group was formed in the United States to help coordinate technical efforts related to information barrier R and D. This paper presents an overview of the efforts of this group, by its Chairs, as well as recommendations for further information barrier R and D. Progress on the demonstration of monitoring systems containing IBs is also provided. From the U.S. perspective, the basic, top-level functional requirements for the information barrier portion of an integrated radiation signature-information barrier inspection system are twofold: The host must be assured that his classified information is protected from disclosure to the inspecting party; and The inspecting party must be confident that the integrated inspection system measures, processes, and presents the radiation-signature-based measurement conclusion in an accurate and reproducible manner. It is the position of the United States that in the absence of any agreement to share classified nuclear weapons design information in the conduct of an inspection regime, the requirement to protect host country classified warhead design information is paramount and admits no tradeoff versus the confidence provided to the inspecting party in the accuracy and reproducibility of the measurements. The U.S. has reached an internal consensus on several critical design elements that define a general standard for radiation signature information barrier design. These criteria have stood the test of time under intense

  12. Interspecific competition and protistan grazing affect the coexistence of freshwater betaproteobacterial strains.

    Czech Academy of Sciences Publication Activity Database

    Salcher, Michaela M.; Ewert, C.; Šimek, Karel; Kasalický, Vojtěch; Posch, T.

    2016-01-01

    Roč. 92, č. 2 (2016), fiv156 ISSN 0168-6496 R&D Projects: GA ČR(CZ) GA13-00243S Institutional support: RVO:60077344 Keywords : betaproteobacteria * chemostat * co-cultivation * flagellate-selective bacterivory * interspecific competition * synergistic cooperation Subject RIV: EE - Microbiology, Virology Impact factor: 3.720, year: 2016

  13. Courtship displays of introgressed, interspecific hybrid Nasonia males : Further investigations into the 'grandfather effect'

    NARCIS (Netherlands)

    Beukeboom, L.W.; Assem, J. van den

    Previously, we investigated courtship behaviour of bidirectional, interspecific hybrid males of two species of Nasonia (Beukeboom & van den Assem, 2001). Characteristics of the displays were intermediate between those of the parental species, but at the same time were biased towards the paternal

  14. Abnormal pollen mitoses (PM I and PM II) in an interspecific hybrid ...

    Indian Academy of Sciences (India)

    Unknown

    sporocytes and pollen grains were prepared by squashing and stained with 0.5% propionic carmine. All meiotic phases and stages of pollen development were evaluated. More than 6000 microspores and pollen grains were care- fully analysed. Keywords. Brachiaria decumbens; Brachiaria ruziziensis; interspecific hybrid; ...

  15. Hydrological Conditions Affect the Interspecific Interaction between Two Emergent Wetland Species

    Directory of Open Access Journals (Sweden)

    Jian Zhou

    2018-01-01

    Full Text Available Hydrological conditions determine the distribution of plant species in wetlands, where conditions such as water depth and hydrological fluctuations are expected to affect the interspecific interactions among emergent wetland species. To test such effects, we conducted a greenhouse experiment with three treatment categories, interspecific interaction (mixed culture or monoculture, water depth (10 or 30 cm depth, and hydrological fluctuation (static or fluctuating water level, and two common emergent wetland plant species, Scirpus planiculumis Fr. (Cyperaceae and Phragmites australis var. baiyangdiansis (Gramineae. An increase in the water depth significantly restrained the growth of both S. planiculumis and P. australis, while hydrological fluctuations did not obviously alter the growth of either species. In addition, both water depth and hydrological fluctuations significantly affected the interspecific interaction between these two wetland species. P. australis benefited from interspecific interaction under increasing water depth and hydrological fluctuations, and the RII values were clearly positive for plants grown at a water depth that fluctuated around 30 cm. The results may have some implications for understanding how S. planiculumis and P. australis, as well as wetland communities, respond to the natural variation or human modification of hydrological conditions.

  16. High prevalence of biofilm synergy among bacterial soil isolates in cocultures indicates bacterial interspecific cooperation

    DEFF Research Database (Denmark)

    Ren, Dawei; Madsen, Jonas Stenløkke; Sørensen, Søren Johannes

    2015-01-01

    of single-species biofilms, indicating that all the individual strains benefit from inclusion in the multispecies community. Our results show a high prevalence of synergy in biofilm formation in multispecies consortia isolated from a natural bacterial habitat and suggest that interspecific cooperation...

  17. Using Crossmatch tests for serological compatibility assessment intra- and interspecific at dogs and cats

    Directory of Open Access Journals (Sweden)

    Sergiu Adrian Muntean

    2016-11-01

    Conclusions: The intraspecific evaluations revealed a high level of blood compatibility in the case of dogs unsensitivized through previous blood transfusions, yet without excluding the possibility of some atypical sensitivization for clinical interest. Having all the interspecific tests exclusively highly positive, we can not sustain a probable xenotransfusion.

  18. Another account of interspecific aggression involving a Hoary Bat (Lasiurus cinereus)

    Science.gov (United States)

    Alyson F Brokaw; Jeff Clerc; Ted Weller

    2016-01-01

    We observed an incident of interspecific aggression between a male Hoary Bat (Lasiurus cinereus) and a male Silver-haired Bat (Lasionycteris noctivagans). The Silver-haired Bat suffered few external injuries, the most conspicuous of which were a missing lower right canine and small...

  19. Interspecific and locational differences in metal levels in edible fish tissue from Saudi Arabia

    KAUST Repository

    Burger, Joanna; Gochfeld, Michael; Batang, Zenon B.; Mannalamkunnath Alikunhi, Nabeel; Aljahdali, Ramzi; Al-Jebreen, Dalal; Aziz, Mohammed A. M.; Al-Suwailem, Abdulaziz M.

    2014-01-01

    species collected from three fishing sites and a local fish market in Jeddah, Saudi Arabia. We tested the following null hypotheses: (1) there are no interspecific differences in metal levels, (2) there are no differences in metal levels in fishes between

  20. An Assessment of Phylogenetic Tools for Analyzing the Interplay Between Interspecific Interactions and Phenotypic Evolution.

    Science.gov (United States)

    Drury, J P; Grether, G F; Garland, T; Morlon, H

    2018-05-01

    Much ecological and evolutionary theory predicts that interspecific interactions often drive phenotypic diversification and that species phenotypes in turn influence species interactions. Several phylogenetic comparative methods have been developed to assess the importance of such processes in nature; however, the statistical properties of these methods have gone largely untested. Focusing mainly on scenarios of competition between closely-related species, we assess the performance of available comparative approaches for analyzing the interplay between interspecific interactions and species phenotypes. We find that many currently used statistical methods often fail to detect the impact of interspecific interactions on trait evolution, that sister-taxa analyses are particularly unreliable in general, and that recently developed process-based models have more satisfactory statistical properties. Methods for detecting predictors of species interactions are generally more reliable than methods for detecting character displacement. In weighing the strengths and weaknesses of different approaches, we hope to provide a clear guide for empiricists testing hypotheses about the reciprocal effect of interspecific interactions and species phenotypes and to inspire further development of process-based models.

  1. Assemblage Organization in Stream Fishes: Effects of Enviromental Variation and Interspecific Interactions

    Science.gov (United States)

    Gary D. Grossman; Robert E. Ratajczak; Maurice Crawford; Mary C. Freeman

    1998-01-01

    We assessed the relative importance of environmental variation, interspecific competition for space, and predator abundance on assemblage structure and microhabitat use in a stream fish assemblage inhabiting Coweeta Creek, North Carolina, USA. Our study encompassed a l0-yr time span (1983-1992) and included some of the highest and lowest flows in the last 58 years. We...

  2. Dynamics of internal waves on the Southeast Florida shelf: Implications for cross-shelf exchange and turbulent mixing on a barrier reef system

    Science.gov (United States)

    Davis, Kristen Alexis

    The dynamics of internal waves shoaling on the Southeast Florida shelf and the resulting stratified turbulence in the shelf bottom boundary layer are investigated using observational studies completed during the summers of 2003-2005. This work is driven by a desire to understand the effects of internal wave-driven flow and the shoreward transport of cool, nutrient-rich water masses on cross-shelf exchange, vertical mixing, and mass transfer to benthic reef organisms. Shelf sea internal wave fields are typically highly variable and dominated by wind and tidal forces. However, this is not necessarily true for outer shelf regions or very narrow shelves where remote physical processes originating over the slope or deep ocean may exert a strong influence on the internal wave climate. During the summers of 2003 and 2004 observational studies were conducted to examine the effects of a western boundary current (the Florida Current), tides, and wind on the mean currents and internal wave field on the outer Southeast Florida shelf. We present evidence that suggests that the Florida Current plays as large a role in the determination of the high frequency internal wave field as tidal forces. These observations and analyses show that it is necessary to include the forcing from the Florida Current meanders and instabilities in order to predict accurately the episodic nature of the internal wave field on the Southeast Florida shelf. Deep ocean and continental shelf processes intersect at the shelf edge and influence the exchange of water masses and their associated characteristics including heat, nutrients, sediment, and larvae across the shelf. Thus, the dynamics of cross-shelf circulation have important consequences for organisms living on the shelf. In the second phase of this work, we investigate physical mechanisms controlling the exchange of water masses during the summer season across the Southeast Florida shelf. A time series of cross-shelf transport from May to August

  3. Floating barrier

    Energy Technology Data Exchange (ETDEWEB)

    1968-05-06

    This floating barrier consists of relatively long elements which can be connected to form a practically continuous assembly. Each element consists of an inflatable tube with an apron of certain height, made of impregnated fabric which is resistant to ocean water and also to hydrocarbons. Means for connecting one element to the following one, and means for attaching ballast to the apron are also provided.

  4. Interspecific associations and community structure: A local survey and analysis in a grass community

    Directory of Open Access Journals (Sweden)

    WenJun Zhang

    2014-09-01

    Full Text Available Interspecific associations in the plant community may help to understand the self-organizing assembly and succession of the community. In present study, Pearson correlation, net correlation, Spearman rank correlation, and point correlation were used to detect the interspecific (inter-family associations of grass species (families using the sampling data collected in a grass community of Zhuhai, China. We found that most associations between grass species (families were positive associations. The competition/interference/niche separation between grass species (families was not significant. A lot of pairs of grass species and families with statistically significant interspecific (inter-family associations based on four correlation measures were discovered. Cluster trees for grass species/families were obtained by using cluster analysis. Relationship among positive/negative associations, interspecific relationship and community succession/stability/robustness was discussed. I held that species with significant positive or negative associations are generally keystone species in the community. Although both negative and positive associations occur in the community succession, the adaptation and selection will finally result in the successful coexistence of the species with significant positive associations in the climax community. As the advance of community succession, the significant positive associations increase and maximize in climax community, and the significant negative associations increase to a maximum and then decline into climax community. Dominance of significant positive associations in the climax community means the relative stablility and equilibrium of the community. No significant associations usually account for the majority of possible interspecific associations at each phase of community succession. They guarantee the robustness of community. They are candidates of keystone species. Lose of some existing keystone species might be

  5. Field reactions of interspecific hybrids of tomato ( Solanum ...

    African Journals Online (AJOL)

    Crosses were made on four selected parent plants in a diallel fashion in 2011. Seedlings of the parent plants and their resulting hybrids were ... The hybrids, W x P and wild x insulata could be selected as they had less leaf spot disease severity and high fruit yield. Keywords: disease incidence, disease severity, heterosis, ...

  6. Chlamydia pneumoniae is genetically diverse in animals and appears to have crossed the host barrier to humans on (at least two occasions.

    Directory of Open Access Journals (Sweden)

    Candice M Mitchell

    2010-05-01

    Full Text Available Chlamydia pneumoniae is a common human and animal pathogen associated with a wide range of diseases. Since the first isolation of C. pneumoniae TWAR in 1965, all human isolates have been essentially clonal, providing little evolutionary insight. To address this gap, we investigated the genetic diversity of 30 isolates from diverse geographical locations, from both human and animal origin (amphibian, reptilian, equine and marsupial. Based on the level of variation that we observed at 23 discreet gene loci, it was clearly evident that the animal isolates were more diverse than the isolates of human origin. Furthermore, we show that C. pneumoniae isolates could be grouped into five major genotypes, A-E, with A, B, D and E genotypes linked by geographical location, whereas genotype C was found across multiple continents. Our evidence strongly supports two separate animal-to-human cross species transfer events in the evolutionary history of this pathogen. The C. pneumoniae human genotype identified in the USA, Canada, Taiwan, Iran, Japan, Korea and Australia (non-Indigenous most likely originated from a single amphibian or reptilian lineage, which appears to have been previously geographically widespread. We identified a separate human lineage present in two Australian Indigenous isolates (independent geographical locations. This lineage is distinct and is present in Australian amphibians as well as a range of Australian marsupials.

  7. Barriers for pregnant women living in rural, agricultural villages to accessing antenatal care in Cambodia: A community-based cross-sectional study combined with a geographic information system.

    Science.gov (United States)

    Yasuoka, Junko; Nanishi, Keiko; Kikuchi, Kimiyo; Suzuki, Sumihiro; Ly, Po; Thavrin, Boukheng; Omatsu, Tsutomu; Mizutani, Tetsuya

    2018-01-01

    Maternal morbidity and mortality is still a major public health issue in low- and middle-income countries such as Cambodia. Improving access to antenatal care (ANC) services for pregnant women has been widely recognized as one of the most effective means of reducing maternal mortality and morbidity. As such, this study examined the barriers for pregnant women living in rural, agricultural villages to accessing ANC based on data collected in the Ratanakiri province, one of the least developed provinces in Cambodia, using a combination of a community-based cross-sectional survey and a geographic information system (GIS). A community-based cross-sectional survey was conducted among 377 mothers with children under the age of two living in 62 villages in the Ratanakiri province, Cambodia, in December 2015. Face-to-face interviews were conducted to ask mothers about their ANC service use, knowledge of ANC, barriers to accessing health facilities, and complications they experienced during the most recent pregnancy. At the same time, GIS data were also collected using a Global Positioning System (GPS) to accurately measure actual travel distance of pregnant women to access health facilities and to examine geographical and environmental barriers in greater detail. Only a third of the mothers met the recommendations made by the World Health Organization (WHO) of receiving ANC four times or more (achieved ANC4+), and a quarter of the mothers had never received ANC during their most recent pregnancy. Factors positively associated with achieving ANC4+ were mother's secondary or higher education (adjusted odds ratio [AOR] = 5.50, 95% confidence interval [CI]: 1.74, 17.37), being aware that receiving ANC is recommended (AOR = 2.74, 95% CI: 1.25, 6.00), and knowledge about the recommended frequency for ANC (AOR = 2.26, 95% CI: 7.22). Actual travel distance was negatively associated with achieving ANC4+. Mothers who had to travel 10.0-14.9 km were 68% less likely (AOR = 0.32, 95

  8. What stage are low-income and middle-income countries (LMICs) at with patient safety curriculum implementation and what are the barriers to implementation? A two-stage cross-sectional study

    Science.gov (United States)

    Ginsburg, Liane R; Dhingra-Kumar, Neelam; Donaldson, Liam J

    2017-01-01

    Objectives The improvement of safety in healthcare worldwide depends in part on the knowledge, skills and attitudes of staff providing care. Greater patient safety content in health professional education and training programmes has been advocated internationally. While WHO Patient Safety Curriculum Guides (for Medical Schools and Multi-Professional Curricula) have been widely disseminated in low-income and middle-income countries (LMICs) over the last several years, little is known about patient safety curriculum implementation beyond high-income countries. The present study examines patient safety curriculum implementation in LMICs. Methods Two cross-sectional surveys were carried out. First, 88 technical officers in Ministries of Health and WHO country offices were surveyed to identify the pattern of patient safety curricula at country level. A second survey followed that gathered information from 71 people in a position to provide institution-level perspectives on patient safety curriculum implementation. Results The majority, 69% (30/44), of the countries were either considering whether to implement a patient safety curriculum or actively planning, rather than actually implementing, or embedding one. Most organisations recognised the need for patient safety education and training and felt a safety curriculum was compatible with the values of their organisation; however, important faculty-level barriers to patient safety curriculum implementation were identified. Key structural markers, such as dedicated financial resources and relevant assessment tools to evaluate trainees’ patient safety knowledge and skills, were in place in fewer than half of organisations studied. Conclusions Greater attention to patient safety curriculum implementation is needed. The barriers to patient safety curriculum implementation we identified in LMICs are not unique to these regions. We propose a framework to act as a global standard for patient safety curriculum implementation

  9. Indicaxanthin from Opuntia ficus-indica Crosses the Blood-Brain Barrier and Modulates Neuronal Bioelectric Activity in Rat Hippocampus at Dietary-Consistent Amounts.

    Science.gov (United States)

    Allegra, Mario; Carletti, Fabio; Gambino, Giuditta; Tutone, Marco; Attanzio, Alessandro; Tesoriere, Luisa; Ferraro, Giuseppe; Sardo, Pierangelo; Almerico, Anna Maria; Livrea, Maria Antonia

    2015-08-26

    Indicaxanthin is a bioactive and bioavailable betalain pigment from the Opuntia ficus-indica fruits. In this in vivo study, kinetic measurements showed that indicaxanthin is revealed in the rat brain within 1 h from oral administration of 2 μmol/kg, an amount compatible with a dietary consumption of cactus pear fruits in humans. A peak (20 ± 2.4 ng of indicaxanthin per whole brain) was measured after 2.5 h; thereafter the molecule disappeared with first order kinetics within 4 h. The potential of indicaxanthin to affect neural activities was in vivo investigated by a microiontophoretic approach. Indicaxanthin, administered in a range between 0.085 ng and 0.34 ng per neuron, dose-dependently modulated the rate of discharge of spontaneously active neurons of the hippocampus, with reduction of the discharge and related changes of latency and duration of the effect. Indicaxanthin (0.34 ng/neuron) showed inhibitory effects on glutamate-induced excitation, indicating activity at the level of glutamatergic synapses. A molecular target of indicaxanthin is suggested by in silico molecular modeling of indicaxanthin with N-methyl-D-aspartate receptor (NMDAR), the most represented of the glutamate receptor family in hippocampus. Therefore, at nutritionally compatible amounts indicaxanthin (i) crosses the rat BBB and accumulates in brain; (ii) can affect the bioelectric activity of hippocampal neurons locally treated with amounts comparable with those measured in the brain; and (iii) modulates glutamate-induced neuronal excitation. The potential of dietary indicaxanthin as a natural neuromodulatory agent deserves further mechanistic and neurophysiologic investigation.

  10. Oro-facial pain perception and barriers to assess oral health care among the children with intellectual disability: A cross-sectional study

    Directory of Open Access Journals (Sweden)

    G Radha

    2015-01-01

    Full Text Available Introduction: Dental caries is one of the most prevalent diseases affecting children invariably across the world; a toothache is one of the common outcomes found to be associated with dental caries as pain perception is a subjective phenomenon reporting of pain may vary among different individuals. The aim of this study was to assess the difference in oral health status and pain perception related to oral health status among the children with intellectual disability (ID and their normal counterparts. Materials and Methods: A cross-sectional study was conducted among 100 school children of 9-14 years with or without ID in Bangalore City, ethical clearance and informed consent were obtained. The study involved 50 children with ID and 50 children with non-ID (NID, of age group 9-14 years. A self-administered questionnaire was used to assess participant′s demographic profile, self-assessed medical and dental conditions. Clinical assessment was done for recording dental caries and gingival status. Dental pain was measured using the "Dental Discomfort Questionnaire +" given by Versloot et al. Results: It was found that children with ID had a higher score for D(T, and M(T compared to NID control. This difference was statistically significant. Children with ID showed higher discomfort due to pain. Except for chewing on one side all other questions showed a significant difference between the groups. Conclusion: It was found that children with ID had a higher caries experience compared to NID control and showed significantly higher pain experience than children with NID.

  11. Measuring Motivation for Appetitive Behaviour: Food-Restricted Broiler Breeder Chickens Cross a Water Barrier to Forage in an Area of Wood Shavings without Food

    Science.gov (United States)

    Dixon, Laura M.; Brocklehurst, Sarah; Sandilands, Vicky; Bateson, Melissa; Tolkamp, Bert J.; D'Eath, Rick B.

    2014-01-01

    Broiler breeders (parents of meat chickens) are selected for fast growth and become obese if fed ad libitum. To avoid this and maintain good health and reproductive ability, they are feed restricted to about 1/3 of what they would eat ad libitum. As a result, they experience chronic hunger and exhibit abnormal behaviour patterns that may indicate stress and frustration. One approach to measuring hunger is to observe how much birds will work, such as pecking a key, for access to more or different types of food. However, the sight, smell, and feedback from consumption of the feed reward changes the context and may artificially raise feeding motivation. To avoid this, we tested broiler breeders in an apparatus in which they could work for access to a wooden platform covered in wood shavings by crossing a water runway which increased in length and depth in 8 successive tests. In the wood shavings area, they could perform exploratory and foraging behaviour (the appetitive phase of feeding) but were never rewarded with feed. Sixty birds were divided into three feed quantity treatments: commercial restriction (R), and twice (2R) or three times (3R) this amount. Overall, birds fed R worked harder to reach the wood shavings area (reached it in a larger number of tests) than 2R and 3R birds (P2R>3R). This indicates that restricted-fed birds were hungry and willing to work for the opportunity to forage even though food was never provided, suggesting that their motivation to perform the appetitive component of feeding behaviour (foraging/food searching) was sufficient to sustain their response. Thus food restriction in broiler breeders is a welfare concern. However these methods could be used to test alternative feeding regimes to attempt to find ways of alleviating hunger while still maintaining healthy growth and reproduction in these birds. PMID:25068283

  12. Barriers to HIV testing, linkage to care, and treatment adherence: a cross-sectional study from a large urban center of Brazil.

    Science.gov (United States)

    MacCarthy, Sarah; Hoffmann, Michael; Nunn, Amy; Silva, Luís Augusto Vasconcelos da; Dourado, Ines

    2016-12-01

    Early, continued engagement with the HIV treatment continuum can help achieve viral suppression, though few studies have explored how risk factors for delays differ across the continuum. The objective of this study was to identify predictors of delayed diagnosis, delayed linkage to care, and nonadherence to treatment in the city of Salvador, Bahia, Brazil. Data were collected during 2010 in a cross-sectional study with a sample (n = 1 970) of HIV-infected individuals enrolled in care. Multiple logistic regression analyses identified sociodemographic variables, behaviors, and measures of health service quality that were associated with delayed diagnosis, delayed linkage to care, and treatment nonadherence. For delayed diagnosis, male gender (adjusted odds ratio (AOR), 3.02; 95% confidence interval (CI), 2.0-4.6); age 45 years and older (AOR, 1.67; 95% CI, 1.1-2.5); and provider-initiated testing (AOR, 3.00; 95% CI, 2.1-4.4) increased odds, while drug use (AOR, 0.29; 95% CI, 0.2-0.5) and receiving results in a private space (AOR, 0.37; 95% CI, 0.2-0.8) decreased odds. For delayed linkage to care, unemployment (AOR, 1.42; 95% CI, 1.07-1.9) and difficulty understanding or speaking with a health care worker (AOR, 1.61; 95% CI, 1.2-2.1) increased odds, while posttest counseling (AOR, 0.49; 95% CI, 0.3-0.7) decreased odds. For nonadherence, experiencing verbal or physical discrimination related to HIV (AOR, 1.94; 95% CI, 1.3-3.0) and feeling mistreated or not properly attended to at HIV care (AOR, 1.60; 95% CI, 1.0-2.5) increased odds, while posttest counseling (AOR, 0.34; 95% CI, 0.2-0.6) decreased odds. More attention is needed on how policies, programs, and research can provide tailored support across the treatment continuum.

  13. Smart parking barrier

    KAUST Repository

    Alharbi, Abdulrazaq M.

    2016-01-01

    positioning of the movable parking barrier, and a parking controller configured to initiate movement of the parking barrier, via the barrier drive. The movable parking barrier can be positioned between a first position that restricts access to the parking

  14. Knowledge and exercise of human rights, and barriers and facilitators to claiming rights: a cross-sectional study of female sex workers and high-risk men who have sex with men in Andhra Pradesh, India.

    Science.gov (United States)

    Ganju, Deepika; Patel, Sangram Kishor; Prabhakar, Parimi; Adhikary, Rajatashurva

    2016-11-17

    HIV prevention interventions recognize the need to protect the rights of key populations and support them to claim their rights as a vulnerability reduction strategy. This study explores knowledge of human rights, and barriers and facilitators to claiming rights, among female sex workers (FSWs) and high-risk men who have sex with men (HR-MSM) who are beneficiaries of a community mobilization intervention in Andhra Pradesh, India. Data are drawn from a cross-sectional survey (2014) among 2400 FSWs and 1200 HR-MSM. Human rights awareness was assessed by asking respondents if they had heard of human rights (yes/no); those reporting awareness of rights were asked to spontaneously name specific rights from the following five pre-defined categories: right to health; dignity/equality; education; property; and freedom from discrimination. Respondents were classified into two groups: more knowledgeable (could identify two or more rights) and less knowledgeable (could identify one or no right). Univariate and bivariate analyses and chi-square tests were used. Data were analyzed using STATA 11.2. Overall 17% FSWs and 8% HR-MSM were not aware of their rights. Among those aware, 62% and 31% respectively were aware of just one or no right (less knowledgeable); only around half (54% vs 57%) were aware of health rights, and fewer (20% vs 16%) aware of their right to freedom from discrimination. Notably, 27% and 17% respectively had not exercised their rights. Barriers to claiming rights among FSWs and HR-MSM were neighbors (35% vs 37%), lack of knowledge (15% vs 14%), stigma (13% vs 22%) and spouse (19% FSWs). Community organizations (COs) were by far the leading facilitator in claiming rights (57% vs 72%). The study findings show that awareness of human rights is limited among FSWs and HR-MSM, and a large proportion have not claimed their rights, elevating their HIV vulnerability. For a sustained HIV response, community mobilization efforts must focus on building key populations

  15. Unilateral compatibility and genotypic difference in crossability in interspecific hybridization between Dianthus caryophyllus L. and Dianthus japonicus Thunb.

    Science.gov (United States)

    Nimura, M; Kato, J; Mii, M; Morioka, K

    2003-05-01

    Reciprocal interspecific crosses were carried out between six lines of Dianthus caryophyllus L. and one line of Dianthus japonicus Thunb. Although no seed was set when D. japonicus was used as the seed parent, six seedlings were successfully obtained from 2,380 immature ovules by applying the embryo-rescue technique. However, they showed seed parent-like morphology and no evidence for the hybridity by flow cytometry and RAPD analyses. When six lines of D. caryophyllus were used as seed parents, a total of 192 seedlings were successfully obtained without using the embryo-rescue technique. Among these seedlings, 12 out of 25 progenies obtained from the carnation line '98sp1651' were confirmed to be the hybrids. The remaining 13 progenies of this line, and the total 167 progenies obtained from the other carnation lines, had carnation-like morphology without any evidence of hybridity by flow cytometry and RAPD analyses. The progenies confirmed as hybrids had intermediate characters of the parents with respect to leaf width and flower size, but they had a uniform flower color, reddish purple, which was different from that of either parent. Since the hybrids obtained in the present study have some profitable characters such as vigorous growth in summer time, upright robust stem, broad leaves and early flowering, they are expected to be used for the breeding of carnation which is suitable for growing under the Japanese climate.

  16. Rin4 Causes Hybrid Necrosis and Race-Specific Resistance in an Interspecific Lettuce Hybrid[W

    Science.gov (United States)

    Jeuken, Marieke J.W.; Zhang, Ningwen W.; McHale, Leah K.; Pelgrom, Koen; den Boer, Erik; Lindhout, Pim; Michelmore, Richard W.; Visser, Richard G.F.; Niks, Rients E.

    2009-01-01

    Some inter- and intraspecific crosses may result in reduced viability or sterility in the offspring, often due to genetic incompatibilities resulting from interactions between two or more loci. Hybrid necrosis is a postzygotic genetic incompatibility that is phenotypically manifested as necrotic lesions on the plant. We observed hybrid necrosis in interspecific lettuce (Lactuca sativa and Lactuca saligna) hybrids that correlated with resistance to downy mildew. Segregation analysis revealed a specific allelic combination at two interacting loci to be responsible. The allelic interaction had two consequences: (1) a quantitative temperature-dependent autoimmunity reaction leading to necrotic lesions, lethality, and quantitative resistance to an otherwise virulent race of Bremia lactucae; and (2) a qualitative temperature-independent race-specific resistance to an avirulent race of B. lactucae. We demonstrated by transient expression and silencing experiments that one of the two interacting genes was Rin4. In Arabidopsis thaliana, RIN4 is known to interact with multiple R gene products, and their interactions result in hypersensitive resistance to Pseudomonas syringae. Site-directed mutation studies on the necrosis-eliciting allele of Rin4 in lettuce showed that three residues were critical for hybrid necrosis. PMID:19855048

  17. Interspecific comparison of the performance of soaring migrants in relation to morphology, meteorological conditions and migration strategies.

    Directory of Open Access Journals (Sweden)

    Ugo Mellone

    Full Text Available BACKGROUND: Performance of migrating birds can be affected by a number of intrinsic and extrinsic factors like morphology, meteorological conditions and migration strategies. We compared travel speeds of four raptor species during their crossing of the Sahara desert. Focusing the analyses on this region allows us to compare different species under equivalent conditions in order to disentangle which factors affect migratory performance. METHODOLOGY/PRINCIPAL FINDING: We tracked raptors using GPS satellite transmitters from Sweden, Spain and Italy, and evaluated their migratory performance at both an hourly and a daily scale. Hourly data (flight speed and altitude for intervals of two hours were analyzed in relation to time of day, species and season, and daily data (distance between roosting sites in relation to species, season, day length and tailwind support. CONCLUSIONS/SIGNIFICANCE: Despite a clear variation in morphology, interspecific differences were generally very small, and did only arise in spring, with long-distance migrants (>5000 km: osprey and Western marsh-harrier being faster than species that migrate shorter distances (Egyptian vulture and short-toed eagle. Our results suggest that the most important factor explaining hourly variation in flight speed is time of day, while at a daily scale, tailwind support is the most important factor explaining variation in daily distance, raising new questions about the consequences of possible future changes in worldwide wind patterns.

  18. Interspecific Hybridization between Sesamum indicum L. and Ceratotheca sesamoides Endl

    Directory of Open Access Journals (Sweden)

    Falusi, OA.

    2001-01-01

    Full Text Available Sesamum indicum L. (2n = 26 and Ceratotheca sesamoides Endl. (2n = 32 were crossed to investigate their genomic relations and feasibility of gene exchange. Results showed that crossability between the two species was low. Pollen viability was drastically reduced in the F1 hybrids. This was attributed to meiotic abnormalities such as univalent and multivalent associations, non-disjunction bridges, and presence of fragments and micronuclei. Findings from this study also imply that gene exchange between Sesamum indicum L. and Ceratotheca sesamoides Endl. is possible. The implications of these results in the species evolution are discussed.

  19. Plant-mediated interspecific horizontal transmission of an intracellular symbiont in insects

    KAUST Repository

    Gonella, Elena

    2015-11-13

    Intracellular reproductive manipulators, such as Candidatus Cardinium and Wolbachia are vertically transmitted to progeny but rarely show co-speciation with the host. In sap-feeding insects, plant tissues have been proposed as alternative horizontal routes of interspecific transmission, but experimental evidence is limited. Here we report results from experiments that show that Cardinium is horizontally transmitted between different phloem sap-feeding insect species through plants. Quantitative PCR and in situ hybridization experiments indicated that the leafhopper Scaphoideus titanus releases Cardinium from its salivary glands during feeding on both artificial media and grapevine leaves. Successional time-course feeding experiments with S. titanus initially fed sugar solutions or small areas of grapevine leaves followed by feeding by the phytoplasma vector Macrosteles quadripunctulatus or the grapevine feeder Empoasca vitis revealed that the symbionts were transmitted to both species. Explaining interspecific horizontal transmission through plants improves our understanding of how symbionts spread, their lifestyle and the symbiont-host intermixed evolutionary pattern.

  20. Does interspecific competition have a moderating effect on Taenia solium transmission dynamics in Southeast Asia?

    Science.gov (United States)

    Conlan, James V; Vongxay, Khamphouth; Fenwick, Stanley; Blacksell, Stuart D; Thompson, R C Andrew

    2009-09-01

    It is well understood that sociocultural practices strongly influence Taenia solium transmission; however, the extent to which interspecific parasite competition moderates Taenia transmission has yet to be determined. This is certainly the case in Southeast Asia where T. solium faces competition in both the definitive host (people) and the intermediate host (pigs). In people, adult worms of T. solium, T. saginata and T. asiatica compete through density-dependent crowding mechanisms. In pigs, metacestodes of T. solium, T. hydatigena and T. asiatica compete through density-dependent immune-mediated interactions. Here, we describe the biological and epidemiological implications of Taenia competition and propose that interspecific competition has a moderating effect on the transmission dynamics of T. solium in the region. Furthermore, we argue that this competitive ecological scenario should be considered in future research and surveillance activities examining T. solium cysticercosis and taeniasis in Southeast Asia.

  1. Plant-mediated interspecific horizontal transmission of an intracellular symbiont in insects.

    Science.gov (United States)

    Gonella, Elena; Pajoro, Massimo; Marzorati, Massimo; Crotti, Elena; Mandrioli, Mauro; Pontini, Marianna; Bulgari, Daniela; Negri, Ilaria; Sacchi, Luciano; Chouaia, Bessem; Daffonchio, Daniele; Alma, Alberto

    2015-11-13

    Intracellular reproductive manipulators, such as Candidatus Cardinium and Wolbachia are vertically transmitted to progeny but rarely show co-speciation with the host. In sap-feeding insects, plant tissues have been proposed as alternative horizontal routes of interspecific transmission, but experimental evidence is limited. Here we report results from experiments that show that Cardinium is horizontally transmitted between different phloem sap-feeding insect species through plants. Quantitative PCR and in situ hybridization experiments indicated that the leafhopper Scaphoideus titanus releases Cardinium from its salivary glands during feeding on both artificial media and grapevine leaves. Successional time-course feeding experiments with S. titanus initially fed sugar solutions or small areas of grapevine leaves followed by feeding by the phytoplasma vector Macrosteles quadripunctulatus or the grapevine feeder Empoasca vitis revealed that the symbionts were transmitted to both species. Explaining interspecific horizontal transmission through plants improves our understanding of how symbionts spread, their lifestyle and the symbiont-host intermixed evolutionary pattern.

  2. Evaluation of cheetah and leopard spermatozoa developmental capability after interspecific ICSI with domestic cat oocytes.

    Science.gov (United States)

    Moro, L N; Sestelo, A J; Salamone, D F

    2014-08-01

    The ICSI procedure is potentially of great value for felids, and it has not been extensively studied in these species. The objectives of this work were to determine the best conditions for ICSI in the domestic cat (DC) to generate interspecific embryos by injecting cheetah (Ch) and leopard (Leo) spermatozoa. Firstly, DC oocytes were matured with insulin-transferrin-selenium (ITS) or without it (MM) and cultured using atmospheric (21%) or low (5%) oxygen tension after ICSI. The group ITS-5%O2 showed the highest blastocyst rate (p cheetah and leopard spermatozoa were able to generate blastocysts without artificial activation, which suggests that developmental capacity of wild felid spermatozoa can be evaluated by interspecific ICSI. This technique should be used to assist wild felid reproduction. © 2014 Blackwell Verlag GmbH.

  3. Meiosis in elephant grass (Pennisetum purpureum), pearl millet (Pennisetum glaucum) (Poaceae, Poales) and their interspecific hybrids

    OpenAIRE

    Techio, Vânia Helena; Davide, Lisete Chamma; Pereira, Antônio Vander

    2006-01-01

    The cultivated and sexually compatible species Pennisetum purpureum (elephant grass, 2n = 4x = 28) and Pennisetum glaucum (pearl millet, 2n = 2x = 14) can undergo hybridization which favors the amplification of their genetic background and the introgression of favorable alleles into breeding programs. The main problem with interspecific hybrids of these species is infertility due to triploidy (2n = 3x = 21). This study describes meiosis in elephant grass x pearl millet hybrids and their proge...

  4. Species-Specific Effects on Ecosystem Functioning Can Be Altered by Interspecific Interactions.

    Science.gov (United States)

    Clare, David S; Spencer, Matthew; Robinson, Leonie A; Frid, Christopher L J

    2016-01-01

    Biological assemblages are constantly undergoing change, with species being introduced, extirpated and experiencing shifts in their densities. Theory and experimentation suggest that the impacts of such change on ecosystem functioning should be predictable based on the biological traits of the species involved. However, interspecific interactions could alter how species affect functioning, with the strength and sign of interactions potentially depending on environmental context (e.g. homogenous vs. heterogeneous conditions) and the function considered. Here, we assessed how concurrent changes to the densities of two common marine benthic invertebrates, Corophium volutator and Hediste diversicolor, affected the ecological functions of organic matter consumption and benthic-pelagic nutrient flux. Complementary experiments were conducted within homogenous laboratory microcosms and naturally heterogeneous field plots. When the densities of the species were increased within microcosms, interspecific interactions enhanced effects on organic matter consumption and reduced effects on nutrient flux. Trait-based predictions of how each species would affect functioning were only consistently supported when the density of the other species was low. In field plots, increasing the density of either species had a positive effect on organic matter consumption (with no significant interspecific interactions) but no effect on nutrient flux. Our results indicate that species-specific effects on ecosystem functioning can be altered by interspecific interactions, which can be either facilitative (positive) or antagonistic (negative) depending on the function considered. The impacts of biodiversity change may therefore not be predictable based solely on the biological traits of the species involved. Possible explanations for why interactions were detected in microcosms but not in the field are discussed.

  5. Species-Specific Effects on Ecosystem Functioning Can Be Altered by Interspecific Interactions.

    Directory of Open Access Journals (Sweden)

    David S Clare

    Full Text Available Biological assemblages are constantly undergoing change, with species being introduced, extirpated and experiencing shifts in their densities. Theory and experimentation suggest that the impacts of such change on ecosystem functioning should be predictable based on the biological traits of the species involved. However, interspecific interactions could alter how species affect functioning, with the strength and sign of interactions potentially depending on environmental context (e.g. homogenous vs. heterogeneous conditions and the function considered. Here, we assessed how concurrent changes to the densities of two common marine benthic invertebrates, Corophium volutator and Hediste diversicolor, affected the ecological functions of organic matter consumption and benthic-pelagic nutrient flux. Complementary experiments were conducted within homogenous laboratory microcosms and naturally heterogeneous field plots. When the densities of the species were increased within microcosms, interspecific interactions enhanced effects on organic matter consumption and reduced effects on nutrient flux. Trait-based predictions of how each species would affect functioning were only consistently supported when the density of the other species was low. In field plots, increasing the density of either species had a positive effect on organic matter consumption (with no significant interspecific interactions but no effect on nutrient flux. Our results indicate that species-specific effects on ecosystem functioning can be altered by interspecific interactions, which can be either facilitative (positive or antagonistic (negative depending on the function considered. The impacts of biodiversity change may therefore not be predictable based solely on the biological traits of the species involved. Possible explanations for why interactions were detected in microcosms but not in the field are discussed.

  6. Impact of interspecific competition and drought on the allocation of new assimilates in trees.

    Science.gov (United States)

    Hommel, R; Siegwolf, R; Zavadlav, S; Arend, M; Schaub, M; Galiano, L; Haeni, M; Kayler, Z E; Gessler, A

    2016-09-01

    In trees, the interplay between reduced carbon assimilation and the inability to transport carbohydrates to the sites of demand under drought might be one of the mechanisms leading to carbon starvation. However, we largely lack knowledge on how drought effects on new assimilate allocation differ between species with different drought sensitivities and how these effects are modified by interspecific competition. We assessed the fate of (13) C labelled assimilates in above- and belowground plant organs and in root/rhizosphere respired CO2 in saplings of drought-tolerant Norway maple (Acer platanoides) and drought-sensitive European beech (Fagus sylvatica) exposed to moderate drought, either in mono- or mixed culture. While drought reduced stomatal conductance and photosynthesis rates in both species, both maintained assimilate transport belowground. Beech even allocated more new assimilate to the roots under moderate drought compared to non-limited water supply conditions, and this pattern was even more pronounced under interspecific competition. Even though maple was a superior competitor compared to beech under non-limited soil water conditions, as indicated by the changes in above- and belowground biomass of both species in the interspecific competition treatments, we can state that beech was still able to efficiently allocate new assimilate belowground under combined drought and interspecific competition. This might be seen as a strategy to maintain root osmotic potential and to prioritise root functioning. Our results thus show that beech tolerates moderate drought stress plus competition without losing its ability to supply belowground tissues. It remains to be explored in future work if this strategy is also valid during long-term drought exposure. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  7. Weak interspecific interactions in a sagebrush steppe? Conflicting evidence from observations and experiments.

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    Adler, Peter B; Kleinhesselink, Andrew; Giles, Hooker; Taylor, J Bret; Teller, Brittany; Ellner, Stephen P

    2018-04-28

    Stable coexistence requires intraspecific limitations to be stronger than interspecific limitations. The greater the difference between intra- and interspecific limitations, the more stable the coexistence, and the weaker the competitive release any species should experience following removal of competitors. We conducted a removal experiment to test whether a previously estimated model, showing surprisingly weak interspecific competition for four dominant species in a sagebrush steppe, accurately predicts competitive release. Our treatments were 1) removal of all perennial grasses and 2) removal of the dominant shrub, Artemisia tripartita. We regressed survival, growth and recruitment on the locations, sizes, and species identities of neighboring plants, along with an indicator variable for removal treatment. If our "baseline" regression model, which accounts for local plant-plant interactions, accurately explains the observed responses to removals, then the removal coefficient should be non-significant. For survival, the removal coefficients were never significantly different from zero, and only A. tripartita showed a (negative) response to removals at the recruitment stage. For growth, the removal treatment effect was significant and positive for two species, Poa secunda and Pseudoroegneria spicata, indicating that the baseline model underestimated interspecific competition. For all three grass species, population models based on the vital rate regressions that included removal effects projected 1.4 to 3-fold increases in equilibrium population size relative to the baseline model (no removal effects). However, we found no evidence of higher response to removal in quadrats with higher pretreatment cover of A. tripartita, or by plants experiencing higher pre-treatment crowding by A. tripartita, raising questions about the mechanisms driving the positive response to removal. While our results show the value of combining observations with a simple removal experiment

  8. Interspecific Transmission of Double-Stranded RNA and Hypovirulence from Sclerotinia sclerotiorum to S. minor.

    Science.gov (United States)

    Melzer, M S; Ikeda, S S; Boland, G J

    2002-07-01

    ABSTRACT Interspecific transmission of a hypovirulence-associated double-stranded RNA (dsRNA) and hypovirulent phenotype was attempted from hypovirulent isolate Ss275 of Sclerotinia sclerotiorum to five virulent isolates of S. minor. dsRNA and the hypovirulent phenotype were successfully transmitted to one of the five isolates, Sm10. Three putative converted isolates of Sm10 were slow growing and developed atypical colony morphologies characteristic of the hypovirulent phenotype. These isolates were assayed for virulence and produced significantly smaller lesions than isolate Sm10 on detached leaves of Romaine lettuce. One of these putative converted isolates, designated Sm10T, was tested to confirm interspecific transmission of dsRNA. In northern hybridizations, dsRNA isolated from Sm10T hybridized with a digoxigenin-labeled cDNA probe prepared from dsRNA isolated from Ss275. Random amplified polymorphic DNA analysis confirmed that isolate Sm10T was derived from Sm10 and not from Ss275 or a hybrid of the two species. The dsRNA and hypovirulent phenotype were subsequently transmitted intraspecifically from Sm10T to Sm8. To our knowledge, this is the first report of interspecific transmission of dsRNA and an associated hypovirulent phenotype between fungal plant pathogens by hyphal anastomosis.

  9. Stabilization process in Saccharomyces intra and interspecific hybrids in fermentative conditions.

    Science.gov (United States)

    Pérez-Través, Laura; Lopes, Christian A; Barrio, Eladio; Querol, Amparo

    2014-12-01

    We evaluated the genetic stabilization of artificial intra- (Saccharomyces cerevisiae) and interspecific (S. cerevisiae × S. kudriavzevii) hybrids under wine fermentative conditions. Large-scale transitions in genome size and genome reorganizations were observed during this process. Interspecific hybrids seem to need fewer generations to reach genetic stability than intraspecific hybrids. The largest number of molecular patterns recovered among the derived clones was observed for intraspecific hybrids, particularly for those obtained by rare-mating. Molecular marker analyses revealed that unstable clones could change during the industrial process to obtain active dry yeast. When no changes in molecular markers and ploidy were observed after this process, no changes in genetic composition were confirmed by comparative genome hybridization, considering the clone as a stable hybrid. According to our results, under these conditions, fermentation steps 3 and 5 (30-50 generations) would suffice to obtain genetically stable interspecific and intraspecific hybrids, respectively. Copyright© by the Spanish Society for Microbiology and Institute for Catalan Studies.

  10. A large set of newly created interspecific Saccharomyces hybrids increases aromatic diversity in lager beers.

    Science.gov (United States)

    Mertens, Stijn; Steensels, Jan; Saels, Veerle; De Rouck, Gert; Aerts, Guido; Verstrepen, Kevin J

    2015-12-01

    Lager beer is the most consumed alcoholic beverage in the world. Its production process is marked by a fermentation conducted at low (8 to 15°C) temperatures and by the use of Saccharomyces pastorianus, an interspecific hybrid between Saccharomyces cerevisiae and the cold-tolerant Saccharomyces eubayanus. Recent whole-genome-sequencing efforts revealed that the currently available lager yeasts belong to one of only two archetypes, "Saaz" and "Frohberg." This limited genetic variation likely reflects that all lager yeasts descend from only two separate interspecific hybridization events, which may also explain the relatively limited aromatic diversity between the available lager beer yeasts compared to, for example, wine and ale beer yeasts. In this study, 31 novel interspecific yeast hybrids were developed, resulting from large-scale robot-assisted selection and breeding between carefully selected strains of S. cerevisiae (six strains) and S. eubayanus (two strains). Interestingly, many of the resulting hybrids showed a broader temperature tolerance than their parental strains and reference S. pastorianus yeasts. Moreover, they combined a high fermentation capacity with a desirable aroma profile in laboratory-scale lager beer fermentations, thereby successfully enriching the currently available lager yeast biodiversity. Pilot-scale trials further confirmed the industrial potential of these hybrids and identified one strain, hybrid H29, which combines a fast fermentation, high attenuation, and the production of a complex, desirable fruity aroma. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  11. Interspecific variation in tree seedlings establishment in canopy gaps in relation to tree density

    Energy Technology Data Exchange (ETDEWEB)

    Reader, R.J.; Bonser, S.P.; Duralia, T.E.; Bricker, B.D. [Guelph Univ., ON (Canada). Dept. of Botany

    1995-10-01

    We tested whether interspecific variation in tree seedling establishment in canopy gaps was significantly related to interspecific variation in tree density, for seven deciduous forest tree species (Quercus alba, Hamamelis virginiana, Acer rubrum, Sassafras albidum, Quercus rubra, Prunus serotina, Ostrya virginiana). For each species, seedling establishment was calculated as the difference in seedling density before experimental gap creation versus three years after gap creation. In each of the six experimentally-created gap types (33% or 66% removal of tree basal area from 0.01ha, 0.05ha or 0.20ha patches), differences in seedling establishment among species were significantly related to differences in their density in the tree canopy. A regression model with log{sub e} tree density as the independent variable accounted for between 93% and 98% of interspecific variation in seedling establishment. Our results provide empirical support for models of tree dynamics in gaps that assume seedling establishment depends on canopy tree density. 17 refs, 1 fig, 3 tabs

  12. Comparison of food hoarding of two sympatric rodent species under interspecific competition.

    Science.gov (United States)

    Zhang, Yi-Feng; Tong, Lei; Ji, Wei-Hong; Lu, Ji-Qi

    2013-01-01

    Competition can greatly affect the food hoarding strategies of rodents and the fate of seeds hoarded. In order to understand the influence of interspecific competition on food caching behavior of sympatric rodents, we investigated food hoarding patterns of two sympatric rodent species, buff-breasted rat (Rattus flavipectus) and Chinese white-bellied rat (Niviventor confucianus), and compared their responses and adjustment in hoarding behavior under interspecific competition. The results showed that: (1) the buff-breasted rat larder hoarded seeds only, while Chinese white-bellied rat hoarded seeds in both larder and scatter forms; (2) two species of rodents both larder hoarded more seeds when competitors were present; and (3) the Chinese white-bellied rats adjusted their seed hoarding from scatter to larder when competitors were introduced, which reduced the seed availability. Therefore, we concluded that rodents would adjust their food hoarding strategy when interspecific competitors were present, and this may produce a different effect on the fate of seeds and the recruitment of plants. This article is part of a Special Issue entitled: insert SI title. Copyright © 2012. Published by Elsevier B.V.

  13. Species composition and interspecific association of plants in primary succession of Mount Merapi, Indonesia

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    SUTOMO

    2011-10-01

    Full Text Available Sutomo, Faradila D, Putri LSE (2011 Species composition and interspecific association of plants in primary succession of Mount Merapi, Indonesia. Biodiversitas 12: 212-217. Primary succession refers to the establishment of plant species and subsequent changes in composition following major disturbance such as volcanic activity. The study of succession may assist in recognizing the possible effects of species interactions (i.e. facilitation or inhibition. The barren landscapes created by volcanic disturbance on Mount Merapi, Java, Indonesia, provide excellent opportunities to study primary succession. Fifty-six species belonging to 26 families were recorded in the five nuées ardentes deposits. The highest number of species belonged to the Asteraceae, then Poaceae, followed by Fabaceae and Rubiaceae. In Mount Merapi primary succession, the ecosystem may be developing with time as indicated by the increase in the number of species associations. The number of positive associations was generally higher than the number of negative associations, except in the 2001 deposit where it was equal. Native and alien invasive species had different patterns of interspecific associations. This research demonstrates that in primary succession sites on Mount Merapi, positive interspecific association increased as time progressed, which may support the view that facilitation is more prominent in a severely disturbed habitat as compared to competition.

  14. Using maize as a model to study pollen tube growth and guidance, cross-incompatibility and sperm delivery in grasses.

    Science.gov (United States)

    Dresselhaus, Thomas; Lausser, Andreas; Márton, Mihaela L

    2011-09-01

    In contrast to animals and lower plants such as mosses and ferns, sperm cells of flowering plants (angiosperms) are immobile and require transportation to the female gametes via the vegetative pollen tube cell to achieve double fertilization. The path of the pollen tube towards the female gametophyte (embryo sac) has been intensively studied in many intra- and interspecific crossing experiments with the aim of increasing the gene pool of crop plants for greater yield, improved biotic and abiotic stress resistance, and for introducing new agronomic traits. Many attempts to hybridize different species or genotypes failed due to the difficulty for the pollen tubes in reaching the female gametophyte. Detailed studies showed that these processes are controlled by various self-incompatible (intraspecific) and cross-incompatible (interspecific) hybridization mechanisms. Understanding the molecular mechanisms of crossing barriers is therefore of great interest in plant reproduction, evolution and breeding research. In particular, pre-zygotic hybridization barriers related to pollen tube germination, growth, guidance and sperm delivery, which are considered the major hybridization controls in nature and thus also contribute to species isolation and speciation, have been intensively investigated. Despite this general interest, surprisingly little is known about these processes in the most important agronomic plant family, the Gramineae, Poaceae or grasses. Small polymorphic proteins and their receptors, degradation of sterility locus proteins and general compounds such as calcium, γ-aminobutyric acid or nitric oxide have been shown to be involved in progamic pollen germination, adhesion, tube growth and guidance, as well as sperm release. Most advances have been made in the Brassicaceae, Papaveraceae, Linderniaceae and Solanaceae families including their well-understood self-incompatibility (SI) systems. Grass species evolved similar mechanisms to control the penetration

  15. What stage are low-income and middle-income countries (LMICs) at with patient safety curriculum implementation and what are the barriers to implementation? A two-stage cross-sectional study.

    Science.gov (United States)

    Ginsburg, Liane R; Dhingra-Kumar, Neelam; Donaldson, Liam J

    2017-06-15

    The improvement of safety in healthcare worldwide depends in part on the knowledge, skills and attitudes of staff providing care. Greater patient safety content in health professional education and training programmes has been advocated internationally. While WHO Patient Safety Curriculum Guides (for Medical Schools and Multi-Professional Curricula) have been widely disseminated in low-income and middle-income countries (LMICs) over the last several years, little is known about patient safety curriculum implementation beyond high-income countries. The present study examines patient safety curriculum implementation in LMICs. Two cross-sectional surveys were carried out. First, 88 technical officers in Ministries of Health and WHO country offices were surveyed to identify the pattern of patient safety curricula at country level. A second survey followed that gathered information from 71 people in a position to provide institution-level perspectives on patient safety curriculum implementation. The majority, 69% (30/44), of the countries were either considering whether to implement a patient safety curriculum or actively planning, rather than actually implementing, or embedding one. Most organisations recognised the need for patient safety education and training and felt a safety curriculum was compatible with the values of their organisation; however, important faculty-level barriers to patient safety curriculum implementation were identified. Key structural markers, such as dedicated financial resources and relevant assessment tools to evaluate trainees' patient safety knowledge and skills, were in place in fewer than half of organisations studied. Greater attention to patient safety curriculum implementation is needed. The barriers to patient safety curriculum implementation we identified in LMICs are not unique to these regions. We propose a framework to act as a global standard for patient safety curriculum implementation. Educating leaders through the system in

  16. Saddle point avoidance in barrier crossing problems

    Energy Technology Data Exchange (ETDEWEB)

    Talkner, P.; Drozdov, A.N. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    The long-time behavior of the stochastic dynamics of a two-dimensional system having two metastable states is investigated by means of the low-lying part of the corresponding two-dimensional Smoluchowski operator. In particular, its dependence on three parameters describing the strength of the noise, the coupling of the degrees of freedom and a ratio of relaxation-times is considered. Further information characterizing the transition process between the metastable states is gained from the corresponding eigenfunctions. (author) 9 refs.

  17. Sprache als Barriere (Language as a Barrier)

    Science.gov (United States)

    Mattheier, Klaus

    1974-01-01

    The concept of language barrier has its derivations in the fields of dialectology, sociology and psychology. In contemporary usage however, the concept has two meanings i.e. regional-cultural barrier and socio-cultural barrier. (Text is in German.) (DS)

  18. Prezygotic barriers to hybridization in marine broadcast spawners: reproductive timing and mating system variation.

    Directory of Open Access Journals (Sweden)

    Carla A Monteiro

    Full Text Available Sympatric assemblages of congeners with incomplete reproductive barriers offer the opportunity to study the roles that ecological and non-ecological factors play in reproductive isolation. While interspecific asynchrony in gamete release and gametic incompatibility are known prezygotic barriers to hybridization, the role of mating system variation has been emphasized in plants. Reproductive isolation between the sibling brown algal species Fucus spiralis, Fucus guiryi (selfing hermaphrodite and Fucus vesiculosus (dioecious was studied because they form hybrids in parapatry in the rocky intertidal zone, maintain species integrity over a broad geographic range, and have contrasting mating systems. We compared reproductive synchrony (spawning overlap between the three species at several temporal scales (yearly/seasonal, semilunar/tidal, and hourly during single tides. Interspecific patterns of egg release were coincident at seasonal (single peak in spring to early summer to semilunar timescales. Synthesis of available data indicated that spawning is controlled by semidiurnal tidal and daily light-dark cues, and not directly by semilunar cycles. Importantly, interspecific shifts in timing detected at the hourly scale during single tides were consistent with a partial ecological prezygotic hybridization barrier. The species displayed patterns of gamete release consistent with a power law distribution, indicating a high degree of reproductive synchrony, while the hypothesis of weaker selective constraints for synchrony in selfing versus outcrossing species was supported by observed spawning in hermaphrodites over a broader range of tidal phase than in outcrossers. Synchronous gamete release is critical to the success of external fertilization, while high-energy intertidal environments may offer only limited windows of reproductive opportunity. Within these windows, however, subtle variations in reproductive timing have evolved with the potential to

  19. An RNA-seq transcriptome analysis of floral buds of an interspecific Brassica hybrid between B. carinata and B. napus.

    Science.gov (United States)

    Chu, Pu; Liu, Huijuan; Yang, Qing; Wang, Yankun; Yan, Guixia; Guan, Rongzhan

    2014-12-01

    Interspecific hybridizations promote gene transfer between species and play an important role in plant speciation and crop improvement. However, hybrid sterility that commonly found in the first generation of hybrids hinders the utilization of interspecific hybridization. The combination of divergent parental genomes can create extensive transcriptome variations, and to determine these gene expression alterations and their effects on hybrids, an interspecific Brassica hybrid of B. carinata × B. napus was generated. Scanning electron microscopy analysis indicated that some of the hybrid pollen grains were irregular in shape and exhibited abnormal exine patterns compared with those from the parents. Using the Illumina HiSeq 2000 platform, 39,598, 32,403 and 42,208 genes were identified in flower buds of B. carinata cv. W29, B. napus cv. Zhongshuang 11 and their hybrids, respectively. The differentially expressed genes were significantly enriched in pollen wall assembly, pollen exine formation, pollen development, pollen tube growth, pollination, gene transcription, macromolecule methylation and translation, which might be associated with impaired fertility in the F1 hybrid. These results will shed light on the mechanisms underlying the low fertility of the interspecific hybrids and expand our knowledge of interspecific hybridization.

  20. Interspecific in vitro assay for the chimera-forming ability of human pluripotent stem cells.

    Science.gov (United States)

    Masaki, Hideki; Kato-Itoh, Megumi; Umino, Ayumi; Sato, Hideyuki; Hamanaka, Sanae; Kobayashi, Toshihiro; Yamaguchi, Tomoyuki; Nishimura, Ken; Ohtaka, Manami; Nakanishi, Mahito; Nakauchi, Hiromitsu

    2015-09-15

    Functional assay limitations are an emerging issue in characterizing human pluripotent stem cells (PSCs). With rodent PSCs, chimera formation using pre-implantation embryos is the gold-standard assay of pluripotency (competence of progeny to differentiate into all three germ layers). In human PSCs (hPSCs), however, this can only be monitored via teratoma formation or in vitro differentiation, as ethical concerns preclude generation of human-human or human-animal chimeras. To circumvent this issue, we developed a functional assay utilizing interspecific blastocyst injection and in vitro culture (interspecies in vitro chimera assay) that enables the development and observation of embryos up to headfold stage. The assay uses mouse pre-implantation embryos and rat, monkey and human PSCs to create interspecies chimeras cultured in vitro to the early egg-cylinder stage. Intra- and interspecific chimera assays with rodent PSC lines were performed to confirm the consistency of results in vitro and in vivo. The behavior of chimeras developed in vitro appeared to recapitulate that of chimeras developed in vivo; that is, PSC-derived cells survived and were integrated into the epiblast of egg-cylinder-stage embryos. This indicates that the interspecific in vitro chimera assay is useful in evaluating the chimera-forming ability of rodent PSCs. However, when human induced PSCs (both conventional and naïve-like types) were injected into mouse embryos and cultured, some human cells survived but were segregated; unlike epiblast-stage rodent PSCs, they never integrated into the epiblast of egg-cylinder-stage embryos. These data suggest that the mouse-human interspecies in vitro chimera assay does not accurately reflect the early developmental potential/process of hPSCs. The use of evolutionarily more closely related species as host embryos might be necessary to evaluate the developmental potency of hPSCs. © 2015. Published by The Company of Biologists Ltd.

  1. Interspecific competition between entomopathogenic nematodes (Steinernema is modified by their bacterial symbionts (Xenorhabdus

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    Pages Sylvie

    2006-09-01

    Full Text Available Abstract Background Symbioses between invertebrates and prokaryotes are biological systems of particular interest in order to study the evolution of mutualism. The symbioses between the entomopathogenic nematodes Steinernema and their bacterial symbiont Xenorhabdus are very tractable model systems. Previous studies demonstrated (i a highly specialized relationship between each strain of nematodes and its naturally associated bacterial strain and (ii that mutualism plays a role in several important life history traits of each partner such as access to insect host resources, dispersal and protection against various biotic and abiotic factors. The goal of the present study was to address the question of the impact of Xenorhabdus symbionts on the progression and outcome of interspecific competition between individuals belonging to different Steinernema species. For this, we monitored experimental interspecific competition between (i two nematode species: S. carpocapsae and S. scapterisci and (ii their respective symbionts: X. nematophila and X. innexi within an experimental insect-host (Galleria mellonella. Three conditions of competition between nematodes were tested: (i infection of insects with aposymbiotic IJs (i.e. without symbiont of both species (ii infection of insects with aposymbiotic IJs of both species in presence of variable proportion of their two Xenorhabdus symbionts and (iii infection of insects with symbiotic IJs (i.e. naturally associated with their symbionts of both species. Results We found that both the progression and the outcome of interspecific competition between entomopathogenic nematodes were influenced by their bacterial symbionts. Thus, the results obtained with aposymbiotic nematodes were totally opposite to those obtained with symbiotic nematodes. Moreover, the experimental introduction of different ratios of Xenorhabdus symbionts in the insect-host during competition between Steinernema modified the proportion of

  2. [Niche and interspecific association of the dominant fish in the south coastal waters of Wenzhou, China].

    Science.gov (United States)

    Dong, Jing Rui; Shui, Bo Nian; Hu, Cheng Ye; Shui, Yu Yue; DU, Xiao; Tian, Kuo

    2017-05-18

    The studies about the niche and interspecific association in China were mainly focused on the plants, birds and marine animals, and seldom on fish. Based on the fishery resources survey in spring (May) and autumn (September) in 2015, the associations among major fish species in south coastal waters of Wenzhou were investigated. The methods including niche breadth, niche overlap, variance ratio (VR), Χ 2 -test, association coefficient (AC), percentage of co-occurrence (PC) and point correlation coefficients (Ф) were used. The results showed that 47 fish species were identified, including 9 orders, 27 families and 41 genera. Four species were dominant species and 9 were important species, which together accounted for 17%. The niche breadth cluster analysis demonstrated two clearly identifiable ecological niches. The first one referred to wide niche that included Harpodon nehereus, Collichthys lucidus, Engraulis japonicas, Pampus echinogaster, Argyrosomus argentatus, Polynemus sextarius, Decapterus maruadsi and Trichiurus haumela, and the second one was narrow niche that included Muraenesox cinereus, Amblychaeturichthys hexanema, Cunoglossus robustus, Pseudosciaena polyactis and Ilisha elongate. The niche overlap value of the main fish was 0-0.90, indicating that there was difference in the resource utilization among the species. The ecological niche widths of C. robustus and M. cinereus were narrow, and the overlap values were high. This indicated that there was competition between these two species. The VR analysis revealed significant positive correlation among the main fish species. In view of the advantages of Ф value, which could reduce the impact of the analysis results of Χ 2 -test, AC and PC to the interspecific association, the Ф value method was selected in this study, and the association of 63 couples were positive. Both the interspecific association and ecological niche had different degrees of correlation with the stability of community structure

  3. Species delimitation and interspecific relationships of the genus Orychophragmus (Brassicaceae inferred from whole chloroplast genomes

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    Huan Hu

    2016-12-01

    Full Text Available IntroductionIt is rather difficult to delimit recently diverged species and construct their interspecific relationships because of insufficient informative variations of sampled DNA fragments (Schluter, 2000; Arnold, 2006. The genome-scale sequence variations were found to increase the phylogenetic resolutions of both high- and low-taxonomic groups (e.g., Yoder et al., 2013; Lamichhaney et al., 2015. It is still expensive to collect nuclear genome variations between species for most none-model genera without the reference genome. However, chloroplast genomes (plastome are relatively easy to be assembled to examine interspecific relationships for phylogenetic analyses, especially in addressing unresolved relationship at low taxonomic levels (Wu et al., 2010; Nock et al., 2011; Yang et al., 2013; Huang et al., 2014; Carbonell-Caballero et al., 2015. Plastomes are haploid with maternal inheritance in most angiosperms (Corriveau and Coleman, 1988; Zhang and Liu, 2003; Hagemann, 2004 and are highly conservative in gene order and genome structure with rare recombinations (Jansen et al., 2007; Moore et al., 2010. In this study, we aimed to examine species delimitation and interspecific relationships in Orychophragmus through assembling chloroplast genomes of multiple individuals of tentatively delimited species (Hu et al., 2015a. Orychophragmus is a small genus in the mustard family (Brassicaceae, Cruciferae distributed in northern, central, and southeastern China (Zhou et al., 2001. Its plants have been widely cultivated as ornamentals, vegetables, or source of seed oil (Sun et al., 2011. Despite controversial species delimitations in the genus (Zhou et al., 1987; Tan et al., 1998; Wu and Zhao, 2003; Al-Shehbaz and Yang, 2000; Zhou et al., 2001; Sun et al., 2012, our recent study based on nuclear (nr ITS sequence variations suggested the recognition of seven species (Hu et al., 2015a. Orychophragmus is sister to Sinalliaria, which is a genus endemic

  4. Native intra- and inter-specific reactions may cause the paradox of pest control with harvesting.

    Science.gov (United States)

    Seno, Hiromi

    2010-05-01

    We analyse a general time-discrete mathematical model of host-parasite population dynamics with harvesting, in which the host can be regarded as a pest. We harvest a portion of the host population at a moment in each year. Our model involves the density effect on the host population. We investigate the condition in which the harvesting of the host results in a paradoxical increase of its equilibrium population size. Our results imply that for a family of pest-enemy systems, the paradox of pest control could be caused essentially by the interspecific relationship and the intraspecific density effect.

  5. Barriers and facilitators to enrollment and re-enrollment into the community health funds/Tiba Kwa Kadi (CHF/TIKA) in Tanzania: a cross-sectional inquiry on the effects of socio-demographic factors and social marketing strategies.

    Science.gov (United States)

    Kapologwe, Ntuli A; Kagaruki, Gibson B; Kalolo, Albino; Ally, Mariam; Shao, Amani; Meshack, Manoris; Stoermer, Manfred; Briet, Amena; Wiedenmayer, Karin; Hoffman, Axel

    2017-04-27

    Introduction of a health insurance scheme is one of the ways to enhance access to health care services and to protect individuals from catastrophic health expenditures. Little is known on the influence of socio-demographic and social marketing strategies on enrollment and re-enrollment in the Community Health Fund/Tiba Kwa Kadi (CHF/TIKA) in Tanzania. This cross-sectional study employed quantitative methods for data collection between November 2014 and March 2015 in Singida and Shinyanga regions. Relationship between variables was obtained through Chi-square test and multivariate logistic regression. We recruited 496 participants in the study. Majority (92.7%) of participants consented to participate, with 229 (49.8%) and 231 (50.2%) members and non members of CHF/TIKA respectively. Majority (90.9%) were aware of CHF/TIKA. Majority of CHF/TIKA members and non-members (90% and 68.3% respectively) reported health facility-based sensitization as the most common social marketing approach employed to market the CHF/TIKA. The most popular marketing strategies in the country including traditional dances, football games, radio, television, news papers, and mosques/church were reported by few CHF and non CHF members. Multivariate Logistic regression models revealed no significant association between social marketing strategies and enrollment, but only socio-demographics; including marital status (AOR = 2.0, 95% CI 1.1-3.8) and family size (household with ≥ 6 members) (AOR = 1.5, 95% CI 1.0-2.5), were significant factors associated with enrollment/re-enrollment rate. This study indicated that low level of utilization of available social marketing strategies and socio-demographic factors are the barriers for attracting members to join the schemes. There is a need for applying various social marketing strategies and considering different facilitating and impending socio-demographic factors for the growth and sustainability of the scheme as we move towards

  6. Epigenetic patterns newly established after interspecific hybridization in natural populations of Solanum

    Science.gov (United States)

    Cara, Nicolás; Marfil, Carlos F; Masuelli, Ricardo W

    2013-01-01

    Interspecific hybridization is known for triggering genetic and epigenetic changes, such as modifications on DNA methylation patterns and impact on phenotypic plasticity and ecological adaptation. Wild potatoes (Solanum, section Petota) are adapted to multiple habitats along the Andes, and natural hybridizations have proven to be a common feature among species of this group. Solanum × rechei, a recently formed hybrid that grows sympatrically with the parental species S. kurtzianum and S. microdontum, represents an ideal model for studying the ecologically and evolutionary importance of hybridization in generating of epigenetic variability. Genetic and epigenetic variability and their correlation with morphological variation were investigated in wild and ex situ conserved populations of these three wild potato species using amplified fragment length polymorphism (AFLP) and methylation-sensitive amplified polymorphism (MSAP) techniques. We observed that novel methylation patterns doubled the number of novel genetic patterns in the hybrid and that the morphological variability measured on 30 characters had a higher correlation with the epigenetic than with the genetic variability. Statistical comparison of methylation levels suggested that the interspecific hybridization induces genome demethylation in the hybrids. A Bayesian analysis of the genetic data reveled the hybrid nature of S. × rechei, with genotypes displaying high levels of admixture with the parental species, while the epigenetic information assigned S. × rechei to its own cluster with low admixture. These findings suggested that after the hybridization event, a novel epigenetic pattern was rapidly established, which might influence the phenotypic plasticity and adaptation of the hybrid to new environments. PMID:24198938

  7. Interspecific variation in egg testosterone levels: implications for the evolution of bird song.

    Science.gov (United States)

    Garamszegi, L Z; Biard, C; Eens, M; Møller, A P; Saino, N

    2007-05-01

    Although interspecific variation in maternal effects via testosterone levels can be mediated by natural selection, little is known about the evolutionary consequences of egg testosterone for sexual selection. However, two nonexclusive evolutionary hypotheses predict an interspecific relationship between egg testosterone levels and the elaboration of sexual traits. First, maternal investment may be particularly enhanced in sexually selected species, which should generate a positive relationship. Secondly, high prenatal testosterone levels may constrain the development of sexual characters, which should result in a negative relationship. Here we investigated these hypotheses by exploring the relationship between yolk testosterone levels and features of song in a phylogenetic study of 36 passerine species. We found that song duration and syllable repertoire size were significantly negatively related to testosterone levels in the egg, even if potentially confounding factors were held constant. These relationships imply that high testosterone levels during early development of songs may be detrimental, thus supporting the developmental constraints hypothesis. By contrast, we found significant evidence that song-post exposure relative to the height of the vegetation is positively related to egg testosterone levels. These results support the hypothesis that high levels of maternal testosterone have evolved in species with intense sexual selection acting on the location of song-posts. We found nonsignificant effects for intersong interval and song type repertoire size, which may suggest that none of the above hypothesis apply to these traits, or they act simultaneously and have opposing effects.

  8. Interspecific RNA interference of SHOOT MERISTEMLESS-like disrupts Cuscuta pentagona plant parasitism.

    Science.gov (United States)

    Alakonya, Amos; Kumar, Ravi; Koenig, Daniel; Kimura, Seisuke; Townsley, Brad; Runo, Steven; Garces, Helena M; Kang, Julie; Yanez, Andrea; David-Schwartz, Rakefet; Machuka, Jesse; Sinha, Neelima

    2012-07-01

    Infection of crop species by parasitic plants is a major agricultural hindrance resulting in substantial crop losses worldwide. Parasitic plants establish vascular connections with the host plant via structures termed haustoria, which allow acquisition of water and nutrients, often to the detriment of the infected host. Despite the agricultural impact of parasitic plants, the molecular and developmental processes by which host/parasitic interactions are established are not well understood. Here, we examine the development and subsequent establishment of haustorial connections by the parasite dodder (Cuscuta pentagona) on tobacco (Nicotiana tabacum) plants. Formation of haustoria in dodder is accompanied by upregulation of dodder KNOTTED-like homeobox transcription factors, including SHOOT MERISTEMLESS-like (STM). We demonstrate interspecific silencing of a STM gene in dodder driven by a vascular-specific promoter in transgenic host plants and find that this silencing disrupts dodder growth. The reduced efficacy of dodder infection on STM RNA interference transgenics results from defects in haustorial connection, development, and establishment. Identification of transgene-specific small RNAs in the parasite, coupled with reduced parasite fecundity and increased growth of the infected host, demonstrates the efficacy of interspecific small RNA-mediated silencing of parasite genes. This technology has the potential to be an effective method of biological control of plant parasite infection.

  9. Interspecific introgression and changes in population structure in a flatfish species complex after the Prestige accident

    International Nuclear Information System (INIS)

    Crego-Prieto, V.; Danancher, D.; Campo, D.; Perez, J.; Garcia-Vazquez, E.; Roca, A.

    2013-01-01

    Highlights: • Impact of Prestige oil spill was studied on two sympatric megrim fish populations. • Samples before and nine years after the accident were genetically analyzed. • A large proportion of post-F1 interspecific hybrids was found in the polluted area. • Both species’ population structure was altered by introgression of foreign alleles. • The spillage likely promoted a hybrid zone for Lepidorhombus in the areas affected. -- Abstract: Oil spills cause aggressive impacts on marine ecosystems affecting immense areas and the species inhabiting them. If wastes are not cleaned up properly, the remnants may affect local populations for a long time. This work focuses on the long-term impacts of the Prestige spillage that occurred off Galician coast (Spain) in November 2002. Model species were two sympatric flatfish, the megrims Lepidorhombus whiffiagonis and Lepidorhombus boscii. Samples obtained before and nine years after the Prestige accident from affected and unaffected areas were genotyped for six hypervariable nuclear markers and for the mitochondrial D-loop sequence. The results revealed a high proportion of post-F1 interspecific hybrids in the area affected, and also increased intraspecific population differentiation likely due to such localized introgression of foreign genes. These changes suggest the appearance of a hybrid zone following the accident and emphasize the need of paying special attention to potential evolutionary impacts of oil spills

  10. Genetic evidence for intra- and interspecific slavery in honey ants (genus Myrmecocystus).

    Science.gov (United States)

    Kronauer, D J C; Gadau, J; Hölldobler, B

    2003-04-22

    The New World honey ant species Myrmecocystus mimicus is well known for its highly stereotyped territorial tournaments, and for the raids on conspecific nests that can lead to intraspecific slavery. Our results from mitochondrial and nuclear markers show that the raided brood emerges in the raiding colony and is subsequently incorporated into the colony's worker force. We also found enslaved conspecifics in a second honey ant species, M. depilis, the sister taxon of M. mimicus, which occurs in sympatry with M. mimicus at the study site. Colonies of this species furthermore contained raided M. mimicus workers. Both species have an effective mating frequency that is not significantly different from 1. This study provides genetic evidence for facultative intra- and interspecific slavery in the genus Myrmecocystus. Slavery in ants has evolved repeatedly and supposedly by different means. We propose that, in honey ants, secondary contact between two closely related species that both exhibit intraspecific slavery gave rise to an early form of facultative interspecific slavery.

  11. Interspecific introgression in cetaceans: DNA markers reveal post-F1 status of a pilot whale.

    Directory of Open Access Journals (Sweden)

    Laura Miralles

    Full Text Available Visual species identification of cetacean strandings is difficult, especially when dead specimens are degraded and/or species are morphologically similar. The two recognised pilot whale species (Globicephala melas and Globicephala macrorhynchus are sympatric in the North Atlantic Ocean. These species are very similar in external appearance and their morphometric characteristics partially overlap; thus visual identification is not always reliable. Genetic species identification ensures correct identification of specimens. Here we have employed one mitochondrial (D-Loop region and eight nuclear loci (microsatellites as genetic markers to identify six stranded pilot whales found in Galicia (Northwest Spain, one of them of ambiguous phenotype. DNA analyses yielded positive amplification of all loci and enabled species identification. Nuclear microsatellite DNA genotypes revealed mixed ancestry for one individual, identified as a post-F1 interspecific hybrid employing two different Bayesian methods. From the mitochondrial sequence the maternal species was Globicephala melas. This is the first hybrid documented between Globicephala melas and G. macrorhynchus, and the first post-F1 hybrid genetically identified between cetaceans, revealing interspecific genetic introgression in marine mammals. We propose to add nuclear loci to genetic databases for cetacean species identification in order to detect hybrid individuals.

  12. Social phenotype extended to communities: expanded multilevel social selection analysis reveals fitness consequences of interspecific interactions.

    Science.gov (United States)

    Campobello, Daniela; Hare, James F; Sarà, Maurizio

    2015-04-01

    In social species, fitness consequences are associated with both individual and social phenotypes. Social selection analysis has quantified the contribution of conspecific social traits to individual fitness. There has been no attempt, however, to apply a social selection approach to quantify the fitness implications of heterospecific social phenotypes. Here, we propose a novel social selection based approach integrating the role of all social interactions at the community level. We extended multilevel selection analysis by including a term accounting for the group phenotype of heterospecifics. We analyzed nest activity as a model social trait common to two species, the lesser kestrel (Falco naumanni) and jackdaw (Corvus monedula), nesting in either single- or mixed-species colonies. By recording reproductive outcome as a measure of relative fitness, our results reveal an asymmetric system wherein only jackdaw breeding performance was affected by the activity phenotypes of both conspecific and heterospecific neighbors. Our model incorporating heterospecific social phenotypes is applicable to animal communities where interacting species share a common social trait, thus allowing an assessment of the selection pressure imposed by interspecific interactions in nature. Finally, we discuss the potential role of ecological limitations accounting for random or preferential assortments among interspecific social phenotypes, and the implications of such processes to community evolution. © 2015 The Author(s).

  13. Arbuscular common mycorrhizal networks mediate intra- and interspecific interactions of two prairie grasses.

    Science.gov (United States)

    Weremijewicz, Joanna; da Silveira Lobo O'Reilly Sternberg, Leonel; Janos, David P

    2018-01-01

    Arbuscular mycorrhizal fungi form extensive common mycorrhizal networks (CMNs) that may interconnect neighboring root systems of the same or different plant species, thereby potentially influencing the distribution of limiting mineral nutrients among plants. We examined how CMNs affected intra- and interspecific interactions within and between populations of Andropogon gerardii, a highly mycorrhiza dependent, dominant prairie grass and Elymus canadensis, a moderately dependent, subordinate prairie species. We grew A. gerardii and E. canadensis alone and intermixed in microcosms, with individual root systems isolated, but either interconnected by CMNs or with CMNs severed weekly. CMNs, which provided access to a large soil volume, improved survival of both A. gerardii and E. canadensis, but intensified intraspecific competition for A. gerardii. When mixed with E. canadensis, A. gerardii overyielded aboveground biomass in the presence of intact CMNs but not when CMNs were severed, suggesting that A. gerardii with intact CMNs most benefitted from weaker interspecific than intraspecific interactions across CMNs. CMNs improved manganese uptake by both species, with the largest plants receiving the most manganese. Enhanced growth in consequence of improved mineral nutrition led to large E. canadensis in intact CMNs experiencing water-stress, as indicated by 13 C isotope abundance. Our findings suggest that in prairie plant communities, CMNs may influence mineral nutrient distribution, water relations, within-species size hierarchies, and between-species interactions.

  14. Testing spatial theories of plant coexistence: no consistent differences in intra- and interspecific interaction distances.

    Science.gov (United States)

    Vogt, Deborah R; Murrell, David J; Stoll, Peter

    2010-01-01

    Plants stand still and interact with their immediate neighbors. Theory has shown that the distances over which these interactions occur may have important consequences for population and community dynamics. In particular, if intraspecific competition occurs over longer distances than interspecific competition (heteromyopia), coexistence can be promoted. We examined how intraspecific and interspecific competition scales with neighbor distance in a target-neighbor greenhouse competition experiment. Individuals from co-occurring forbs from calcareous grasslands were grown in isolation and with single conspecific or heterospecific neighbors at distances of 5, 10, or 15 cm (Plantago lanceolata vs. Plantago media and Hieracium pilosella vs. Prunella grandiflora). Neighbor effects were strong and declined with distance. Interaction distances varied greatly within and between species, but we found no evidence for heteromyopia. Instead, neighbor identity effects were mostly explained by relative size differences between target and neighbor. We found a complex interaction between final neighbor size and identity such that neighbor identity may become important only as the neighbor becomes very large compared with the target individual. Our results suggest that species-specific size differences between neighboring individuals determine both the strength of competitive interactions and the distance over which these interactions occur.

  15. Interspecific competition and the structure of bird guilds in boreal Europe: the importance of doing fieldwork in the right season.

    Science.gov (United States)

    Oksanen, L

    1987-12-01

    Bird studies have gained a central role in the debate on the importance of interspecific competition in nature. Thus, the negative results reported from a breeding bird community in a North American shrubsteppe area have created ripples throughout community ecology. However, the set of coexisting breeding birds might be an inappropriate operational definition of a bird community, because the intensity of interspecific competition can be expected to peak in autumn-winter. A review of North European data on wintering birds suggests that the case for the competition theory remains strong when bird communities are defined on the basis of winter coexistence. Copyright © 1987. Published by Elsevier Ltd.

  16. Smart parking barrier

    KAUST Repository

    Alharbi, Abdulrazaq M.

    2016-05-06

    Various methods and systems are provided for smart parking barriers. In one example, among others, a smart parking barrier system includes a movable parking barrier located at one end of a parking space, a barrier drive configured to control positioning of the movable parking barrier, and a parking controller configured to initiate movement of the parking barrier, via the barrier drive. The movable parking barrier can be positioned between a first position that restricts access to the parking space and a second position that allows access to the parking space. The parking controller can initiate movement of the movable parking barrier in response to a positive identification of an individual allowed to use the parking space. The parking controller can identify the individual through, e.g., a RFID tag, a mobile device (e.g., a remote control, smartphone, tablet, etc.), an access card, biometric information, or other appropriate identifier.

  17. Regulation of Cross-holdings between European Companies

    DEFF Research Database (Denmark)

    Sørensen, Karsten Engsig

    2003-01-01

    Cross-holdings can be a barrier to takeovers, and they may have other disadvantages. This article analyses how cross-holdings may be regulated to avoid these negative effects.......Cross-holdings can be a barrier to takeovers, and they may have other disadvantages. This article analyses how cross-holdings may be regulated to avoid these negative effects....

  18. Use of electrical barriers to deter movement of round goby

    Science.gov (United States)

    Savino, Jacqueline F.; Jude, David J.; Kostich, Melissa J.; Coutant, Charles C.

    2001-01-01

    An electrical barrier was chosen as a possible means to deter movement of round goby Neogobius melanostomus. Feasibility studies in a 2.1-m donut-shaped tank determined the electrical parameters necessary to inhibit round goby from crossing the 1-m stretch of the benthic, electrical barrier. Increasing electrical pulse duration and voltage increased effectiveness of the barrier in deterring round goby movement through the barrier. Differences in activity of round goby during daytime and nocturnal tests did not change the effectiveness of the barrier. In field verification studies, an electrical barrier was placed between two blocking nets in the Shiawassee River, Michigan. The barrier consisted of a 6-m wide canvas on which were laid four cables carrying the electrical current. Seven experiments were conducted, wherein 25 latex paint-marked round goby were introduced upstream of the electrical barrier and recovered 24 h later upstream, on, and downstream of the barrier. During control studies, round goby moved across the barrier within 20 min from release upstream. With the barrier on and using the prescribed electrical settings shown to inhibit passage in the laboratory, the only marked round goby found below the barrier were dead. At reduced pulse durations, a few round goby (mean one/test) were found alive, but debilitated, below the barrier. The electrical barrier could be incorporated as part of a program in reducing movement of adult round goby through artificial connections between watersheds.

  19. Barriers to Physical Activity in Individuals with Spinal Cord Injury

    DEFF Research Database (Denmark)

    Roberton, Terri; Bucks, Romola S.; Skinner, Timothy C.

    2011-01-01

    This study examined barriers to physical activity reported individuals with spinal cord injury (SCI) and the degree to which these barriers differed across varying degrees of independence. Participants were 65 individuals recruited from the Western Australian Spinal Cord Injury database. Data...... on physical activity participation and perceived barriers to physical activity participation were collected using a cross-sectional survey and analysed using independent samples t-tests. We found that, regardless of level of ambulation or ability to transfer, few participants reported being physically active....... While there were no significant differences in the amount of barriers reported by individuals with different levels of independence, the type of barriers reported varied across groups....

  20. Carotenoid accumulation and carotenogenic gene expression during fruit development in novel interspecific inbred squash lines and their parents.

    Science.gov (United States)

    Nakkanong, Korakot; Yang, Jing Hua; Zhang, Ming Fang

    2012-06-13

    Carotenoid levels and composition during squash fruit development were compared in Cucurbita moschata , Cucurbita maxima , and two lines of their interspecific inbred lines, namely, Maxchata1 and Maxchata2. Eight genes associated with carotenoid biosynthesis were analyzed by quantitative RT-PCR. The two squash species and their interspecific inbred lines exhibited different qualitative and quantitative carotenoid profiles and regulatory mechanisms. C. moschata had the lowest total carotenoid content and mainly accumulated α-carotene and β-carotene, as expected in a fruit with pale-orange flesh. Low carotenoid content in this species was probably due to the comparatively low expression of all genes investigated, especially PSY1 gene, compared to the other squashes. The predominant carotenoids in C. maxima were violaxanthin and lutein, which produced a corresponding yellow flesh color in mature fruit. The relationship between the expression of the CHYB and ZEP genes may result in almost equal concentrations of violaxanthin and lutein in C. maxima at fruit ripening. In contrast, their interspecific inbred lines principally accumulated lutein and β-carotene, leading to orange flesh color. The PSY1 gene exhibited higher expression levels at earlier stages of fruit development in the Maxchata lines, potentially triggering the increased carotenoid accumulation seen in these fruits. Likewise, the higher transcription level of CHYB gene observed in the two interspecific inbred lines might be correlated with high lutein in these hybrids. However, this study could not explain the observed β-carotene accumulation on the basis of gene expression.

  1. Evidence for the Emergence of New Rice Types of Interspecific Hybrid Origin in West African Farmers' Fields

    NARCIS (Netherlands)

    Nuijten, H.A.C.P.; Treuren, van R.; Struik, P.C.; Mokuwa, G.A.; Okry, F.; Teeken, B.W.E.; Richards, P.

    2009-01-01

    In West Africa two rice species (Oryza glaberrima Steud. and Oryza sativa L.) co-exist. Although originally it was thought that interspecific hybridization is impossible without biotechnological methods, progenies of hybridization appear to occur in farmer fields. AFLP analysis was used to assess

  2. Somatic embryogenesis from corolla tubes of interspecific amphiploids between cultivated sunflower (Helianthus annuus L.) and its wild species

    Science.gov (United States)

    Somatic embryogenesis in vitro provides an efficient means of plant multiplication, facilitating sunflower improvement and germplasm innovation. In the present study, using interspecific amphiploids (2n=4x=68) between cultivated sunflower and wild perennial Helianthus species as explant donors, soma...

  3. (S)-(+)-Ipsdienol: Interspecific Inhibition of Ips latidens (LeConte) by Ips pini (Say) (Coleoptera: Scolytidae)

    Science.gov (United States)

    Daniel R. Miller; John H. Borden

    1992-01-01

    In south-central British Columbia, the attraction of Ips latidens (LeConte) to its pheromone, ipsenol, was inhibited by (S)-(+)-ipsdienol, a pheromone for I. pini (Say). (R)-(-)-Ipsdienol had no effect on I. latidens. (S)-(+)-lpsdienol probably plays a role in interspecific communication between the two species...

  4. Permeability Barrier Generation in the Martian Lithosphere

    Science.gov (United States)

    Schools, Joe; Montési, Laurent

    2015-11-01

    Permeability barriers develop when a magma produced in the interior of a planet rises into the cooler lithosphere and crystallizes more rapidly than the lithosphere can deform (Sparks and Parmentier, 1991). Crystallization products may then clog the porous network in which melt is propagating, reducing the permeability to almost zero, i.e., forming a permeability barrier. Subsequent melts cannot cross the barrier. Permeability barriers have been useful to explain variations in crustal thickness at mid-ocean ridges on Earth (Magde et al., 1997; Hebert and Montési, 2011; Montési et al., 2011). We explore here under what conditions permeability barriers may form on Mars.We use the MELTS thermodynamic calculator (Ghiorso and Sack, 1995; Ghiorso et al., 2002; Asimow et al., 2004) in conjunction with estimated Martian mantle compositions (Morgan and Anders, 1979; Wänke and Dreibus, 1994; Lodders and Fegley, 1997; Sanloup et al., 1999; Taylor 2013) to model the formation of permeability barriers in the lithosphere of Mars. In order to represent potential past and present conditions of Mars, we vary the lithospheric thickness, mantle potential temperature (heat flux), oxygen fugacity, and water content.Our results show that permeability layers can develop in the thermal boundary layer of the simulated Martian lithosphere if the mantle potential temperature is higher than ~1500°C. The various Martian mantle compositions yield barriers in the same locations, under matching variable conditions. There is no significant difference in barrier location over the range of accepted Martian oxygen fugacity values. Water content is the most significant influence on barrier development as it reduces the temperature of crystallization, allowing melt to rise further into the lithosphere. Our lower temperature and thicker lithosphere model runs, which are likely the most similar to modern Mars, show no permeability barrier generation. Losing the possibility of having a permeability

  5. Barrier cell sheath formation

    International Nuclear Information System (INIS)

    Kesner, J.

    1980-04-01

    The solution for electrostatic potential within a simply modeled tandem mirror thermal barrier is seen to exhibit a sheath at each edge of the cell. The formation of the sheath requires ion collisionality and the analysis assmes that the collisional trapping rate into the barrier is considerably slower than the barrier pump rate

  6. Abnormal spindle orientation during microsporogenesis in an interspecific Brachiaria (Gramineae hybrid

    Directory of Open Access Journals (Sweden)

    Andréa Beatriz Mendes-Bonato

    2006-01-01

    Full Text Available This paper reports a case of abnormal spindle orientation during microsporogenesis in an interspecific hybrid of the tropical grass Brachiaria. In the affected plant, prophase I was normal. In metaphase I, bivalents were regularly co-oriented but distantly positioned and spread over the equatorial plate. In anaphase I, chromosomes failed to converge into focused poles due to parallel spindle fibers. As a consequence, in telophase I, an elongated nucleus or several micronuclei were observed in each pole. In the second division, the behavior was the same, leading to polyads with several micronuclei. A total of 40% of meiotic products were affected. The use of this hybrid in production systems needing good-quality seeds is discussed.

  7. Embryogenic calli induced in interspecific (Elaeis guineensis x E. oleifera hybrid zygotic embryos

    Directory of Open Access Journals (Sweden)

    Paula Cristina da Silva Angelo

    2009-01-01

    Full Text Available The hybridization between oil palm (Elaeis guineensis and caiaué (E. oleifera plants is directed to obtainprogenies presenting high yields like oil palm but with reduced shoot height and resistance to lethal yellowing like caiaué.Cloning F1, BC1 and BC2 progenies can make the replication of selection trials easier. The objective of this work was to inducesomatic embryogenesis in interspecific zygotic embryos collected 100 days after pollination. Three progenies were cultivatedin an induction medium developed for Tenera (E. guineensis tp. dura x pisifera embryos. The number of embryos bearing calliand germinating was recorded and submitted to the Z test. Calli were weighted and submitted to histological analysis.Progenies differed in the number of embryos presenting plumules and calli simultaneously. By the ninth month, the apices ofincompletely developed somatic embryos were observed protruding from the surfaces of nodular calli. Highly embryogenicand friable secondary calli producing globular somatic embryos were not observed.

  8. First report of interspecific facultative social parasitism in the paper wasp genus Mischocyttarus Saussure (Hymenoptera, Vespidae

    Directory of Open Access Journals (Sweden)

    Thiago S. Montagna

    2012-06-01

    Full Text Available First report of interspecific facultative social parasitism in the paper wasp genus Mischocyttarus Saussure (Hymenoptera, Vespidae. Parasitism of colonies of the social wasp Mischocyttarus cerberus Ducke, 1918 by females of Mischocyttarus consimilis Zikán, 1949 was observed in a rural area of Dourados, state of Mato Grosso do Sul, Brazil. In all monitored cases, the invasion occurred in the pre-emergence colony stage, generally by a single female of M. consimilis. The period of establishment of the foreign female in the host colony was marked by antagonistic behaviors between the host female and the invasive. In general, the architecture of the parasitized nest was modified from the typical architecture of the host species nest.

  9. Interspecific sex in grass smuts and the genetic diversity of their pheromone-receptor system.

    Directory of Open Access Journals (Sweden)

    Ronny Kellner

    2011-12-01

    Full Text Available The grass smuts comprise a speciose group of biotrophic plant parasites, so-called Ustilaginaceae, which are specifically adapted to hosts of sweet grasses, the Poaceae family. Mating takes a central role in their life cycle, as it initiates parasitism by a morphological and physiological transition from saprobic yeast cells to pathogenic filaments. As in other fungi, sexual identity is determined by specific genomic regions encoding allelic variants of a pheromone-receptor (PR system and heterodimerising transcription factors. Both operate in a biphasic mating process that starts with PR-triggered recognition, directed growth of conjugation hyphae, and plasmogamy of compatible mating partners. So far, studies on the PR system of grass smuts revealed diverse interspecific compatibility and mating type determination. However, many questions concerning the specificity and evolutionary origin of the PR system remain unanswered. Combining comparative genetics and biological approaches, we report on the specificity of the PR system and its genetic diversity in 10 species spanning about 100 million years of mating type evolution. We show that three highly syntenic PR alleles are prevalent among members of the Ustilaginaceae, favouring a triallelic determination as the plesiomorphic characteristic of this group. Furthermore, the analysis of PR loci revealed increased genetic diversity of single PR locus genes compared to genes of flanking regions. Performing interspecies sex tests, we detected a high potential for hybridisation that is directly linked to pheromone signalling as known from intraspecies sex. Although the PR system seems to be optimised for intraspecific compatibility, the observed functional plasticity of the PR system increases the potential for interspecific sex, which might allow the hybrid-based genesis of newly combined host specificities.

  10. Phenology and interspecific association of Forficula auricularia and Forficula pubescens in apple orchards

    Directory of Open Access Journals (Sweden)

    Jaume Lordan

    2015-03-01

    Full Text Available The European earwig Forficula auricularia L. (Dermaptera: Forficulidae has been widely studied as a key predator of pests in temperate regions, but its phenology and behavior may differ in warmer areas such as the Mediterranean. Here we assessed the phenology, aggregation, and interspecific association of F. auricularia and Forficula pubescens Gené, the only two species found consistently in both ground and canopy shelters in Mediterranean apple orchards. In addition to F. auricularia and F. pubescens, three other earwig species, namely Labidura riparia Pallas, Nala lividipes Dufour and Euborellia moesta Gené, were found occasionally. The mature stages of F. auricularia were observed mainly from May to November in tree shelters and immature ones from October to June in ground shelters. Adult individuals of F. pubescens were observed year-round and nymph instars were detected from April to June in ground as well as in tree shelters. The suitability of the current degree-days models for temperate regions was evaluated for the prediction of European earwig phenology in a Mediterranean climate. Regarding interspecific association, F. auricularia and F. pubescens co-occurred in canopies without apparent competition. This study provides useful weekly data about the phenology of the two earwig species throughout the year that can be used to detect the key periods during which to enhance their populations in pip fruit orchards or to control them in stone fruit crops. Furthermore, our results are of relevance for the development of new phenological models of earwigs in Mediterranean areas where nymphs hibernate, a feature that makes current models inaccurate.

  11. Host responses to interspecific brood parasitism: a by-product of adaptations to conspecific parasitism?

    Science.gov (United States)

    Samas, Peter; Hauber, Mark E; Cassey, Phillip; Grim, Tomas

    2014-01-01

    Why have birds evolved the ability to reject eggs? Typically, foreign egg discrimination is interpreted as evidence that interspecific brood parasitism (IP) has selected for the host's ability to recognize and eliminate foreign eggs. Fewer studies explore the alternative hypothesis that rejection of interspecific eggs is a by-product of host defenses, evolved against conspecific parasitism (CP). We performed a large scale study with replication across taxa (two congeneric Turdus thrushes), space (populations), time (breeding seasons), and treatments (three types of experimental eggs), using a consistent design of egg rejection experiments (n = 1057 nests; including controls), in areas with potential IP either present (Europe; native populations) or absent (New Zealand; introduced populations). These comparisons benefited from the known length of allopatry (one and a half centuries), with no gene flow between native and introduced populations, which is rarely available in host-parasite systems. Hosts rejected CP at unusually high rates for passerines (up to 60%). CP rejection rates were higher in populations with higher conspecific breeding densities and no risks of IP, supporting the CP hypothesis. IP rejection rates did not covary geographically with IP risk, contradicting the IP hypothesis. High egg rejection rates were maintained in the relatively long-term isolation from IP despite non-trivial rejection costs and errors. These egg rejection patterns, combined with recent findings that these thrushes are currently unsuitable hosts of the obligate parasitic common cuckoo (Cuculus canorus), are in agreement with the hypothesis that the rejection of IP is a by-product of fine-tuned egg discrimination evolved due to CP. Our study highlights the importance of considering both IP and CP simultaneously as potential drivers in the evolution of egg discrimination, and illustrates how populations introduced to novel ecological contexts can provide critical insights

  12. Spatial distribution and interspecific associations of tree species in a tropical seasonal rain forest of China.

    Directory of Open Access Journals (Sweden)

    Guoyu Lan

    Full Text Available Studying the spatial pattern and interspecific associations of plant species may provide valuable insights into processes and mechanisms that maintain species coexistence. Point pattern analysis was used to analyze the spatial distribution patterns of twenty dominant tree species, their interspecific spatial associations and changes across life stages in a 20-ha permanent plot of seasonal tropical rainforest in Xishuangbanna, China, to test mechanisms maintaining species coexistence. Torus-translation tests were used to quantify positive or negative associations of the species to topographic habitats. The results showed: (1 fourteen of the twenty tree species were negatively (or positively associated with one or two of the topographic variables, which evidences that the niche contributes to the spatial pattern of these species. (2 Most saplings of the study species showed a significantly clumped distribution at small scales (0-10 m which was lost at larger scales (10-30 m. (3 The degree of spatial clumping deceases from saplings, to poles, to adults indicates that density-dependent mortality of the offspring is ubiquitous in species. (4 It is notable that a high number of positive small-scale interactions were found among the twenty species. For saplings, 42.6% of all combinations of species pairs showed positive associations at neighborhood scales up to five meters, but only 38.4% were negative. For poles and adults, positive associations at these distances still made up 45.5% and 29.5%, respectively. In conclusion, there is considerable evidence for the presence of positive interactions among the tree species, which suggests that species herd protection may occur in our plot. In addition, niche assembly and limited dispersal (likely contribute to the spatial patterns of tree species in the tropical seasonal rain forest in Xishuangbanna, China.

  13. Development of a set of SSR markers for genetic polymorphism detection and interspecific hybrid jute breeding

    Directory of Open Access Journals (Sweden)

    Dipnarayan Saha

    2017-10-01

    Full Text Available Corchorus capsularis (white jute and C. olitorius (dark jute are the two principal cultivated species of jute that produce natural bast fiber of commercial importance. We have identified 4509 simple sequence repeat (SSR loci from 34,163 unigene sequences of C. capsularis to develop a non-redundant set of 2079 flanking primer pairs. Among the SSRs, trinucleotide repeats were most frequent (60% followed by dinucleotide repeats (37.6%. Annotation of the SSR-containing unigenes revealed their putative functions in various biological and molecular processes, including responses to biotic and abiotic signals. Eighteen expressed gene-derived SSR (eSSR markers were successfully mapped to the existing single-nucleotide polymorphism (SNP linkage map of jute, providing additional anchor points. Amplification of 72% of the 74 randomly selected primer pairs was successful in a panel of 24 jute accessions, comprising five and twelve accessions of C. capsularis and C. olitorius, respectively, and seven wild jute species. Forty-three primer pairs produced an average of 2.7 alleles and 58.1% polymorphism in a panel of 24 jute accessions. The mean PIC value was 0.34 but some markers showed PIC values higher than 0.5, suggesting that these markers can efficiently measure genetic diversity and serve for mapping of quantitative trait loci (QTLs in jute. A primer polymorphism survey with parents of a wide-hybridized population between a cultivated jute and its wild relative revealed their efficacy for interspecific hybrid identification. For ready accessibility of jute eSSR primers, we compiled all information in a user-friendly web database, JuteMarkerdb (http://jutemarkerdb.icar.gov.in/ for the first time in jute. This eSSR resource in jute is expected to be of use in characterization of germplasm, interspecific hybrid and variety identification, and marker-assisted breeding of superior-quality jute.

  14. Environmental determinism, and not interspecific competition, drives morphological variability in Australasian warblers (Acanthizidae).

    Science.gov (United States)

    García-Navas, Vicente; Rodríguez-Rey, Marta; Marki, Petter Z; Christidis, Les

    2018-04-01

    Interspecific competition is thought to play a key role in determining the coexistence of closely related species within adaptive radiations. Competition for ecological resources can lead to different outcomes from character displacement to, ultimately, competitive exclusion. Accordingly, divergent natural selection should disfavor those species that are the most similar to their competitor in resource use, thereby increasing morphological disparity. Here, we examined ecomorphological variability within an Australo-Papuan bird radiation, the Acanthizidae, which include both allopatric and sympatric complexes. In addition, we investigated whether morphological similarities between species are related to environmental factors at fine scale (foraging niche) and/or large scale (climate). Contrary to that predicted by the competition hypothesis, we did not find a significant correlation between the morphological similarities found between species and their degree of range overlap. Comparative modeling based on both a priori and data-driven identification of selective regimes suggested that foraging niche is a poor predictor of morphological variability in acanthizids. By contrast, our results indicate that climatic conditions were an important factor in the formation of morphological variation. We found a significant negative correlation between species scores for PC1 (positively associated to tarsus length and tail length) and both temperature and precipitation, whereas PC2 (positively associated to bill length and wing length) correlated positively with precipitation. In addition, we found that species inhabiting the same region are closer to each other in morphospace than to species outside that region regardless of genus to which they belong or its foraging strategy. Our results indicate that the conservative body form of acanthizids is one that can work under a wide variety of environments (an all-purpose morphology), and the observed interspecific similarity is

  15. Phenology and interspecific association of Forficula auricularia and Forficula pubescens in apple orchards

    Energy Technology Data Exchange (ETDEWEB)

    Lordan, J.; Alegre, S.; Moerkens, R.; Sarasúa, M.J.; Alins, G.

    2015-07-01

    The European earwig Forficula auricularia L. (Dermaptera: Forficulidae) has been widely studied as a key predator of pests in temperate regions, but its phenology and behavior may differ in warmer areas such as the Mediterranean. Here we assessed the phenology, aggregation, and interspecific association of F. auricularia and Forficula pubescens Gené, the only two species found consistently in both ground and canopy shelters in Mediterranean apple orchards. In addition to F. auricularia and F. pubescens, three other earwig species, namely Labidura riparia Pallas, Nala lividipes Dufour and Euborellia moesta Gené, were found occasionally. The mature stages of F. auricularia were observed mainly from May to November in tree shelters and immature ones from October to June in ground shelters. Adult individuals of F. pubescens were observed year-round and nymph instars were detected from April to June in ground as well as in tree shelters. The suitability of the current degree-days models for temperate regions was evaluated for the prediction of European earwig phenology in a Mediterranean climate. Regarding interspecific association, F. auricularia and F. pubescens co-occurred in canopies without apparent competition. This study provides useful weekly data about the phenology of the two earwig species throughout the year that can be used to detect the key periods during which to enhance their populations in pip fruit orchards or to control them in stone fruit crops. Furthermore, our results are of relevance for the development of new phenological models of earwigs in Mediterranean areas where nymphs hibernate, a feature that makes current models inaccurate. (Author)

  16. Interspecific semantic alarm call recognition in the solitary Sahamalaza sportive lemur, Lepilemur sahamalazensis.

    Directory of Open Access Journals (Sweden)

    Melanie Seiler

    Full Text Available As alarm calls indicate the presence of predators, the correct interpretation of alarm calls, including those of other species, is essential for predator avoidance. Conversely, communication calls of other species might indicate the perceived absence of a predator and hence allow a reduction in vigilance. This "eavesdropping" was demonstrated in birds and mammals, including lemur species. Interspecific communication between taxonomic groups has so far been reported in some reptiles and mammals, including three primate species. So far, neither semantic nor interspecific communication has been tested in a solitary and nocturnal lemur species. The aim of this study was to investigate if the nocturnal and solitary Sahamalaza sportive lemur, Lepilemur sahamalazensis, is able to access semantic information of sympatric species. During the day, this species faces the risk of falling prey to aerial and terrestrial predators and therefore shows high levels of vigilance. We presented alarm calls of the crested coua, the Madagascar magpie-robin and aerial, terrestrial and agitation alarm calls of the blue-eyed black lemur to 19 individual Sahamalaza sportive lemurs resting in tree holes. Songs of both bird species' and contact calls of the blue-eyed black lemur were used as a control. After alarm calls of crested coua, Madagascar magpie-robin and aerial alarm of the blue-eyed black lemur, the lemurs scanned up and their vigilance increased significantly. After presentation of terrestrial alarm and agitation calls of the blue-eyed black lemur, the animals did not show significant changes in scanning direction or in the duration of vigilance. Sportive lemur vigilance decreased after playbacks of songs of the bird species and contact calls of blue-eyed black lemurs. Our results indicate that the Sahamalaza sportive lemur is capable of using information on predator presence as well as predator type of different sympatric species, using their referential

  17. Interspecific variation in the tetradactyl manus of modern tapirs (Perissodactyla: Tapirus) exposed using geometric morphometrics.

    Science.gov (United States)

    MacLaren, Jamie A; Nauwelaerts, Sandra

    2017-11-01

    The distal forelimb (autopodium) of quadrupedal mammals is a key morphological unit involved in locomotion, body support, and interaction with the substrate. The manus of the tapir (Perissodactyla: Tapirus) is unique within modern perissodactyls, as it retains the plesiomorphic tetradactyl (four-toed) condition also exhibited by basal equids and rhinoceroses. Tapirs are known to exhibit anatomical mesaxonic symmetry in the manus, although interspecific differences and biomechanical mesaxony have yet to be rigorously tested. Here, we investigate variation in the manus morphology of four modern tapir species (Tapirus indicus, Tapirus bairdii, Tapirus pinchaque, and Tapirus terrestris) using a geometric morphometric approach. Autopodial bones were laser scanned to capture surface shape and morphology was quantified using 3D-landmark analysis. Landmarks were aligned using Generalised Procrustes Analysis, with discriminant function and partial least square analyses performed on aligned coordinate data to identify features that significantly separate tapir species. Overall, our results support the previously held hypothesis that T. indicus is morphologically separate from neotropical tapirs; however, previous conclusions regarding function from morphological differences are shown to require reassessment. We find evidence indicating that T. bairdii exhibits reduced reliance on the lateral fifth digit compared to other tapirs. Morphometric assessment of the metacarpophalangeal joint and the morphology of the distal facets of the lunate lend evidence toward high loading on the lateral digits of both the large T. indicus (large body mass) and the small, long limbed T. pinchaque (ground impact). Our results support other recent studies on T. pinchaque, suggesting subtle but important adaptations to a compliant but inclined habitat. In conclusion, we demonstrate further evidence that the modern tapir forelimb is a variable locomotor unit with a range of interspecific features

  18. PROPAGATION OF KHAYA ANTHOTHECA: INTERSPECIFIC GRAFTING WITH SWIETENIA MACROPHYLLA AND AIR LAYERING

    Directory of Open Access Journals (Sweden)

    Joamir Barbosa Filho

    2016-12-01

    Full Text Available Swietenia macrophylla yields high-quality wood; however, its vulnerability to extinction coupled with challenges for its cultivation have brought attention to its replacement for alternative species such as the Khaya anthotheca. The species has been recently introduced to South America, with potential for the production of high-quality wood. However, limited background on breeding and efficient strategies for its vegetative propagation exist. Here, we achieved significant results with the application of cleft grafting and air layering for the propagation of K. anthotheca plants grown from seeds. First, we analyzed the compatibility of scions and rootstocks for intraspecific and interspecific cleft grafting combinations of K. anthotheca and S. macrophylla. Second, air layering was performed in K. anthotheca seedlings irrigated with three nutrient solution (100%, 50% and 25% of the initial concentration of nutrients combined with the application of indole-3-butyric acid (IBA to evaluate adventitious rooting. From cleft grafting, we achieved an overall graft compatibility and survival of 48% after 200 days. However, the interspecific combination of S. macrophylla (scion and K. anthotheca (rootstock implicated in no compatibility, while the reciprocal resulted in 52% of compatibility. Through air layering, the irrigation with the nutrient solution with at least 50% of the nutrients concentration and with IBA (3.0 or 8.0 g.L-1 resulted in the best adventitious rooting. Overall, we recommend cleft grafting, except for the combination S. macrophylla(scion and K. anthotheca (rootstock, with no compatibility. Air layering might also be useful for the propagation of K. anthotheca genotypes in breeding programs.

  19. Interspecific differences between D. pulex and D. magna in tolerance to cyanobacteria with protease inhibitors.

    Directory of Open Access Journals (Sweden)

    Christian J Kuster

    Full Text Available It is known that cyanobacteria negatively affect herbivores due to their production of toxins such as protease inhibitors. In the present study we investigated potential interspecific differences between two major herbivores, Daphnia magna and Daphnia pulex, in terms of their tolerance to cyanobacteria with protease inhibitors. Seven clones each of D. magna and of D. pulex were isolated from different habitats in Europe and North America. To test for interspecific differences in the daphnids' tolerance to cyanobacteria, their somatic and population growth rates were determined for each D. magna and D. pulex clone after exposure to varying concentrations of two Microcystis aeruginosa strains. The M. aeruginosa strains NIVA and PCC(- contained either chymotrypsin or trypsin inhibitors, but no microcystins. Mean somatic and population growth rates on a diet with 20% NIVA were significantly more reduced in D. pulex than in D. magna. On a diet with 10% PCC(-, the population growth of D. pulex was significantly more reduced than that of D. magna. This indicates that D. magna is more tolerant to cyanobacteria with protease inhibitors than D. pulex. The reduction of growth rates was possibly caused by an interference of cyanobacterial inhibitors with proteases in the gut of Daphnia, as many other conceivable factors, which might have been able to explain the reduced growth, could be excluded as causal factors. Protease assays revealed that the sensitivities of chymotrypsins and trypsins to cyanobacterial protease inhibitors did not differ between D. magna and D. pulex. However, D. magna exhibited a 2.3-fold higher specific chymotrypsin activity than D. pulex, which explains the observed higher tolerance to cyanobacterial protease inhibitors of D. magna. The present study suggests that D. magna may control the development of cyanobacterial blooms more efficiently than D. pulex due to differences in their tolerance to cyanobacteria with protease

  20. Interspecific reciprocity explains mobbing behaviour of the breeding chaffinches, Fringilla coelebs.

    Science.gov (United States)

    Krams, Indrikis; Krama, Tatjana

    2002-01-01

    When prey animals discover a predator close by, they mob it while uttering characteristic sounds that attract other prey individuals to the vicinity. Mobbing causes a predator to vacate its immediate foraging area, which gives an opportunity for prey individuals to continue their interrupted daily activity. Besides the increased benefits, mobbing behaviour also has its costs owing to injuries or death. The initiator of mobbing may be at increased risk of predation by attracting the predator's attention, especially if not joined by other neighbouring prey individuals. Communities of breeding birds have always been considered as temporal aggregations. Since an altruist could not prevent cheaters from exploiting its altruism in an anonymous community, this excluded any possibility of explaining mobbing behaviour in terms of reciprocal altruism. However, sedentary birds may have become acquainted since the previous non-breeding season. Migrant birds, forming anonymous communities at the beginning of the breeding season, may also develop closer social ties during the course of the breeding season. We tested whether a male chaffinch, a migrant bird, would initiate active harassment of a predator both at the beginning of the breeding season and a week later when it has become a member of a non-anonymous multi-species aggregation of sedentary birds. We expected that male chaffinches would be less likely to initiate a mob at the beginning of the breeding season when part of an anonymous multi-species aggregation of migratory birds. However, their mobbing activity should increase as the breeding season advances. Our results support these predictions. Cooperation among individuals belonging to different species in driving the predator away may be explained as interspecific reciprocity based on interspecific recognition and temporal stability of the breeding communities. PMID:12495502

  1. Interspecific and locational differences in metal levels in edible fish tissue from Saudi Arabia

    KAUST Repository

    Burger, Joanna

    2014-07-06

    Metal levels in fish have been extensively studied, but little data currently exists for the Middle East. We examined the levels of metals and metalloids (aluminum, arsenic, copper, manganese, selenium, zinc, and mercury) in the flesh of 13 fish species collected from three fishing sites and a local fish market in Jeddah, Saudi Arabia. We tested the following null hypotheses: (1) there are no interspecific differences in metal levels, (2) there are no differences in metal levels in fishes between market and fishing sites, (3) there are no size-related differences in metal levels, and (4) there are no differences in selenium:mercury molar ratio among different fish species. There were significant interspecific differences in concentrations for all metals. There was an order of magnitude difference in the levels of aluminum, arsenic, mercury, manganese, and selenium, indicating wide variation in potential effects on the fish themselves and on their predators. Fishes from Area II, close to a large commercial port, had the highest levels of arsenic, mercury, and selenium, followed by market fishes. Mercury was positively correlated with body size in 6 of the 13 fish species examined. Mercury was correlated positively with arsenic and selenium, but negatively with aluminum, cobalt, copper, manganese, and zinc. Selenium:mercury molar ratios varied significantly among species, with Carangoides bajad, Cephalopholis argus, Variola louti, and Ephinephelus tauvina having ratios below 10:1. These findings can be used in risk assessments, design of mercury reduction plans, development of fish advisories to protect public health, and future management decision-making.

  2. Barriers to fusion

    International Nuclear Information System (INIS)

    Berriman, A.C.; Butt, R.D.; Dasgupta, M.; Hinde, D.J.; Morton, C.R.; Newton, J.O.

    1999-01-01

    The fusion barrier is formed by the combination of the repulsive Coulomb and attractive nuclear forces. Recent research at the Australian National University has shown that when heavy nuclei collide, instead of a single fusion barrier, there is a set of fusion barriers. These arise due to intrinsic properties of the interacting nuclei such deformation, rotations and vibrations. Thus the range of barrier energies depends on the properties of both nuclei. The transfer of matter between nuclei, forming a neck, can also affect the fusion process. High precision data have been used to determine fusion barrier distributions for many nuclear reactions, leading to new insights into the fusion process

  3. Extremal surface barriers

    International Nuclear Information System (INIS)

    Engelhardt, Netta; Wall, Aron C.

    2014-01-01

    We present a generic condition for Lorentzian manifolds to have a barrier that limits the reach of boundary-anchored extremal surfaces of arbitrary dimension. We show that any surface with nonpositive extrinsic curvature is a barrier, in the sense that extremal surfaces cannot be continuously deformed past it. Furthermore, the outermost barrier surface has nonnegative extrinsic curvature. Under certain conditions, we show that the existence of trapped surfaces implies a barrier, and conversely. In the context of AdS/CFT, these barriers imply that it is impossible to reconstruct the entire bulk using extremal surfaces. We comment on the implications for the firewall controversy

  4. Safety- barrier diagrams

    DEFF Research Database (Denmark)

    Duijm, Nijs Jan

    2008-01-01

    Safety-barrier diagrams and the related so-called 'bow-tie' diagrams have become popular methods in risk analysis. This paper describes the syntax and principles for constructing consistent and valid safety-barrier diagrams. The relation of safety-barrier diagrams to other methods such as fault...... trees and Bayesian networks is discussed. A simple method for quantification of safety-barrier diagrams is proposed. It is concluded that safety-barrier diagrams provide a useful framework for an electronic data structure that integrates information from risk analysis with operational safety management....

  5. Safety-barrier diagrams

    DEFF Research Database (Denmark)

    Duijm, Nijs Jan

    2007-01-01

    Safety-barrier diagrams and the related so-called "bow-tie" diagrams have become popular methods in risk analysis. This paper describes the syntax and principles for constructing consistent and valid safety-barrier diagrams. The relation with other methods such as fault trees and Bayesian networks...... are discussed. A simple method for quantification of safety-barrier diagrams is proposed, including situations where safety barriers depend on shared common elements. It is concluded that safety-barrier diagrams provide a useful framework for an electronic data structure that integrates information from risk...... analysis with operational safety management....

  6. Genetic dissection of growth, wood basic density and gene expression in interspecific backcrosses of Eucalyptus grandis and E. urophylla

    Science.gov (United States)

    2012-01-01

    Background F1 hybrid clones of Eucalyptus grandis and E. urophylla are widely grown for pulp and paper production in tropical and subtropical regions. Volume growth and wood quality are priority objectives in Eucalyptus tree improvement. The molecular basis of quantitative variation and trait expression in eucalypt hybrids, however, remains largely unknown. The recent availability of a draft genome sequence (http://www.phytozome.net) and genome-wide genotyping platforms, combined with high levels of genetic variation and high linkage disequilibrium in hybrid crosses, greatly facilitate the detection of quantitative trait loci (QTLs) as well as underlying candidate genes for growth and wood property traits. In this study, we used Diversity Arrays Technology markers to assess the genetic architecture of volume growth (diameter at breast height, DBH) and wood basic density in four-year-old progeny of an interspecific backcross pedigree of E. grandis and E. urophylla. In addition, we used Illumina RNA-Seq expression profiling in the E. urophylla backcross family to identify cis- and trans-acting polymorphisms (eQTLs) affecting transcript abundance of genes underlying QTLs for wood basic density. Results A total of five QTLs for DBH and 12 for wood basic density were identified in the two backcross families. Individual QTLs for DBH and wood basic density explained 3.1 to 12.2% of phenotypic variation. Candidate genes underlying QTLs for wood basic density on linkage groups 8 and 9 were found to share trans-acting eQTLs located on linkage groups 4 and 10, which in turn coincided with QTLs for wood basic density suggesting that these QTLs represent segregating components of an underlying transcriptional network. Conclusion This is the first demonstration of the use of next-generation expression profiling to quantify transcript abundance in a segregating tree population and identify candidate genes potentially affecting wood property variation. The QTLs identified in this

  7. Fusion barrier distributions - What have we learned?

    International Nuclear Information System (INIS)

    Hinde, D. J.; Dasgupta, M.

    1998-01-01

    The study of nuclear fusion received a strong impetus from the realisation that an experimental fusion barrier distribution could be determined from precisely measured fusion cross-sections. Experimental data for different reactions have shown in the fusion barrier distributions clear signatures of a range of nuclear excitations, for example the effects of static quadrupole and hexadecapole deformations, single- and double-phonon states, transfer of nucleons, and high-lying excited states. The improved understanding of fusion barrier distributions allows more reliable prediction of fusion angular momentum distributions, which aids interpretation of fission probabilities and fission anisotropies, and understanding of the population of super-deformed bands for nuclear structure studies. Studies of the relationship between the fusion barrier distribution and the extra-push energy should improve our understanding of the mechanism of the extra-push effect, and may help to predict new ways of forming very heavy or super-heavy nuclei

  8. Performance evaluation of cable median barrier systems in Texas.

    Science.gov (United States)

    2009-08-01

    Since 2003, the Texas Department of Transportation (TxDOT) has embarked on an aggressive campaign to install : median barriers to prevent cross-median crashes on freeway facilities statewide. In the few years prior to 2003, : virtually all fatalities...

  9. Development of guidelines for cable median barrier systems in Texas.

    Science.gov (United States)

    2009-12-01

    Since 2003, the Texas Department of Transportation (TxDOT) has embarked on an aggressive campaign to install : median barriers to prevent cross-median crashes on freeway facilities statewide. In the few years prior to 2003, : virtually all fatalities...

  10. Overcoming barriers to work participation for patients with postpoliomyelitis syndrome

    NARCIS (Netherlands)

    ten Katen, Kim; Beelen, Anita; Nollet, Frans; Frings-Dresen, Monique H. W.; Sluiter, Judith K.

    2011-01-01

    Purpose. This study aimed to explore the perceived work ability of patients with postpoliomyelitis syndrome (PPS), to identify barriers and factors that are impeding or conducive, respectively, to work participation, and to identify possible interventions. Methods. Qualitative cross-sectional

  11. Sub-barrier capture with quantum diffusion approach

    Directory of Open Access Journals (Sweden)

    Scheid W.

    2011-10-01

    Full Text Available With the quantum diffusion approach the behavior of capture cross sections and mean-square angular momenta of captured systems are revealed in the reactions with deformed and spherical nuclei at sub-barrier energies. With decreasing bombarding energy under the barrier the external turning point of the nucleus-nucleus potential leaves the region of short-range nuclear interaction and action of friction. Because of this change of the regime of interaction, an unexpected enhancement of the capture cross section is found at bombarding energies far below the Coulomb barrier. This effect is shown its worth in the dependence of mean-square angular momentum on the bombarding energy. From the comparison of calculated capture cross sections and experimental capture or fusion cross sections the importance of quasifission near the entrance channel is demonstrated for the actinidebased reactions and reactions with medium-heavy nuclei at extreme sub-barrier energies.

  12. 7Li breakup polarization potential at near barrier energies

    International Nuclear Information System (INIS)

    Lubian, J. . E-mail lubian@if.uff.br; Correa, T.; Paes, B.; Figueira, J.M.; Abriola, D.; Fernandez Niello, J.O.; Arazi, A.; Capurro, O.A.; de Barbara, E.; Marti, G.V.; Martinez Heinmann, D.; Negri, A.E.; Pacheco, A.J.; Padron, I.; Gomes, P.R.S.

    2007-01-01

    Inelastic and one neutron transfer cross sections at energies around the Coulomb barrier were used to derive dynamic polarization potential (DPP) for the 7 Li + 27 Al system. The DPP due to breakup, obtained in a simple way, indicates that its real part is repulsive at near barrier energies

  13. Inbreeding, heterosis, fertility, plasmon differentiation and Phytophthora resistance in Solanum verrucosum Schlechtd., and some interspecific crosses in Solanum

    NARCIS (Netherlands)

    Abdalla, M.M.F.

    1970-01-01

    Solanum verrucosum (2n = 24) is a self-compatible, highly fertile species. This conclusion is drawn from the results of studies on 21 various introductions of this species. In spite of self-compatibility and good male and female fertility, the species generally needs a pollinating agent to

  14. The result of a two-stages cross intra and interspecific selection of sugar cane crop potential clones

    Directory of Open Access Journals (Sweden)

    Herwati A.

    2017-06-01

    Full Text Available Sugarcane is one of strategic and important food commodities in Indonesia because it is the main source of sugar producers. Domestic sugar production in 2015 only reached 2.5 million tons, while its needs are 5.6 million tons which resulting in a shortage of 3.1 million tons to be met from import. The production in 2016 just reached 2.5 million tons causing the shortages that must be filled by import as much as 3.1 million tons. The Ministry of Agriculture has a program for sugar self-sufficiency that is expected to be achieved by 2014 with production is expected to reach 5.7 million tons. The discrepancy between production levels at this time with the target in 2014 still quite wide. The target accession can be reached by intensification and land extension or expansion. The availability of land development with the availability of adequate water has to face obstacles competing with rice plant as the main staple food. In 2007 more than 60% sugar cane crop was in dry land (Hadisaputro, et al., 2008. The expansion of dry land still has an opportunity to be developed in various ways such as the availability of sugar cane varieties with drought resistant. The research objectives are to accomplish the drought resistant selection in the field to the result of crossbreeding clones in 2014 (MLG-14. The activities implemented in KP. Karangploso, Malang, started on January until December 2016. The research materials are 51 crop clones of two stage selection which 7 varieties are PSDK, PSJT 941, PS 881, PSJK, VMC 76-16, GLAGAH, ERIANTHUS, CENING, BL, and PS 881 as a control. Using a randomized block design with three replication were planted in plots consisting of three arc along the 5 m. The PKP range (from center to center of arc are 100 cm length. The range between replications is 2.5 – 3 cm length. The seeds form is a one eye mule (bud set. Furthermore, after 1.5 month old, the seeds were selected based on its uniformly conditions and then planted in the segment with the range of 50 cm length between plants, so the plants amount per plot as many as 30 plants. Fertilizer dose of 160 kg N + 70 kg P2O5+ 60 kg K2O per hectare or equivalent to 800 kg ZA + 200 kg SP36 + 100 kg KCl per hectare. Observation were did at the age of 11 months. The parameter that being observed were plant height, stem lenght, number of stems/ clump, steam diameter, number of segments, heavy stems intact, heavy stem/ m, the brix average, and voos of stem. The result showed the highest parameters in comparison with the parent for plant height (347 cm and the stem lenght (301 cm is MLG 02/14/86, the number of stem, not voos of stem productive MLG 14/2/42 (45 stems, stem’s diameter and not voos of stem,VMC 76-16 (39.8 cm, not voos of stem, the amount of segments MLG 14/5/15 (27 segments, not voos of stem and ERIANTHUS (27.6, stem’s weight, MLG 14/2/44 (2.12 kg, and the brix average value not voos of stem and BL (24.7% not voos of stem.

  15. Global gene expression profiling related to temperature-sensitive growth abnormalities in interspecific crosses between tetraploid wheat and Aegilops tauschii.

    Directory of Open Access Journals (Sweden)

    Ryusuke Matsuda

    Full Text Available Triploid wheat hybrids between tetraploid wheat and Aegilops tauschii sometimes show abnormal growth phenotypes, and the growth abnormalities inhibit generation of wheat synthetic hexaploids. In type II necrosis, one of the growth abnormalities, necrotic cell death accompanied by marked growth repression occurs only under low temperature conditions. At normal temperature, the type II necrosis lines show grass-clump dwarfism with no necrotic symptoms, excess tillers, severe dwarfism and delayed flowering. Here, we report comparative expression analyses to elucidate the molecular mechanisms of the temperature-dependent phenotypic plasticity in the triploid wheat hybrids. We compared gene and small RNA expression profiles in crown tissues to characterize the temperature-dependent phenotypic plasticity. No up-regulation of defense-related genes was observed under the normal temperature, and down-regulation of wheat APETALA1-like MADS-box genes, considered to act as flowering promoters, was found in the grass-clump dwarf lines. Some microRNAs, including miR156, were up-regulated, whereas the levels of transcripts of the miR156 target genes SPLs, known to inhibit tiller and branch number, were reduced in crown tissues of the grass-clump dwarf lines at the normal temperature. Unusual expression of the miR156/SPLs module could explain the grass-clump dwarf phenotype. Dramatic alteration of gene expression profiles, including miRNA levels, in crown tissues is associated with the temperature-dependent phenotypic plasticity in type II necrosis/grass-clump dwarf wheat hybrids.

  16. Effects of gamma-ray irradiation on interspecific hybridization between Chamaecyparis obtusa S. et Z. and Chamaecyparis pisifera S. et Z

    Energy Technology Data Exchange (ETDEWEB)

    Maeta, Takehiko (Institute of Radiation Breeding, Omiya, Ibaraki (Japan))

    1982-03-01

    C. obtusa S. et Z. is one of the most important forest trees in Japan, and possesses high wood quality. It adapts to dry or semi-dry planting sites, but when it is planted in humid and productive soil, physiological damage is often seen, and its woods are not resistant against termite harm. On the contrary, C. pisifera S. et Z. has high adaptability to humid and productive soil, and is resistant against termite harm. In order to improve the resistance of C. obtusa against diseases and insects, an attempt to obtain a hybrid between C. obtusa and C. pisifera has been made. However, it was found to be very difficult to obtain the hybrid because of low cross compatibility. Therefore, the radiosensitivity of reproductive organs and the induction of mutation in C. obtusa and C. pisifera, the cause of interspecific incompatibility between both species, and the possibility of breaking down the incompatibility were investigated. Also, the cytological screening of the hybrids between C. obtusa and C. pisifera was made. It was considered that the acute gamma-ray irradiation from 500 to 600 R on male flowers was optimum for the hybridization of the present purpose. All of the hybrids produced in this study were triploid.

  17. Effects of gamma-ray irradiation on interspecific hybridization between Chamaecyparis obtusa S. et Z. and Chamaecyparis pisifera S. et Z

    International Nuclear Information System (INIS)

    Maeta, Takehiko

    1982-01-01

    C. obtusa S. et Z. is one of the most important forest trees in Japan, and possesses high wood quality. It adapts to dry or semi-dry planting sites, but when it is planted in humid and productive soil, physiological damage is often seen, and its woods are not resistant against termite harm. On the contrary, C. pisifera S. et Z. has high adaptability to humid and productive soil, and is resistant against termite harm. In order to improve the resistance of C. obtusa against diseases and insects, an attempt to obtain a hybrid between C. obtusa and C. pisifera has been made. However, it was found to be very difficult to obtain the hybrid because of low cross compatibility. Therefore, the radiosensitivity of reproductive organs and the induction of mutation in C. obtusa and C. pisifera, the cause of interspecific incompatibility between both species, and the possibility of breaking down the incompatibility were investigated. Also, the cytological screening of the hybrids between C. obtusa and C. pisifera was made. It was considered that the acute gamma-ray irradiation from 500 to 600 R on male flowers was optimum for the hybridization of the present purpose. All of the hybrids produced in this study were triploid. (Kako, I.)

  18. Multilayer moisture barrier

    Science.gov (United States)

    Pankow, Joel W; Jorgensen, Gary J; Terwilliger, Kent M; Glick, Stephen H; Isomaki, Nora; Harkonen, Kari; Turkulainen, Tommy

    2015-04-21

    A moisture barrier, device or product having a moisture barrier or a method of fabricating a moisture barrier having at least a polymer layer, and interfacial layer, and a barrier layer. The polymer layer may be fabricated from any suitable polymer including, but not limited to, fluoropolymers such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), or ethylene-tetrafluoroethylene (ETFE). The interfacial layer may be formed by atomic layer deposition (ALD). In embodiments featuring an ALD interfacial layer, the deposited interfacial substance may be, but is not limited to, Al.sub.2O.sub.3, AlSiO.sub.x, TiO.sub.2, and an Al.sub.2O.sub.3/TiO.sub.2 laminate. The barrier layer associated with the interfacial layer may be deposited by plasma enhanced chemical vapor deposition (PECVD). The barrier layer may be a SiO.sub.xN.sub.y film.

  19. Barrier penetration database

    International Nuclear Information System (INIS)

    Fainberg, A.; Bieber, A.M. Jr.

    1978-11-01

    This document is intended to supply the NRC and nuclear power plant licensees with basic data on the times required to penetrate forcibly the types of barriers commonly found in nuclear plants. These times are necessary for design and evaluation of the physical protection system required under 10CFR73.55. Each barrier listed is described in detail. Minor variations in basic barrier construction that result in the same penetration time, are also described

  20. Transport barriers in plasmas

    International Nuclear Information System (INIS)

    Caldas, I L; Szezech, J D Jr; Kroetz, T; Marcus, F A; Roberto, M; Viana, R L; Lopes, S R

    2012-01-01

    We discuss the creation of transport barriers in magnetically confined plasmas with non monotonic equilibrium radial profiles. These barriers reduce the transport in the shearless region (i.e., where the twist condition does not hold). For the chaotic motion of particles in an equilibrium electric field with a nonmonotonic radial profile, perturbed by electrostatic waves, we show that a nontwist transport barrier can be created in the plasma by modifying the electric field radial profile. We also show non twist barriers in chaotic magnetic field line transport in the plasma near to the tokamak wall with resonant modes due to electric currents in external coils.

  1. Feline Immunodeficiency Virus Cross-Species Transmission: Implications for Emergence of New Lentiviral Infections.

    Science.gov (United States)

    Lee, Justin; Malmberg, Jennifer L; Wood, Britta A; Hladky, Sahaja; Troyer, Ryan; Roelke, Melody; Cunningham, Mark; McBride, Roy; Vickers, Winston; Boyce, Walter; Boydston, Erin; Serieys, Laurel; Riley, Seth; Crooks, Kevin; VandeWoude, Sue

    2017-03-01

    Owing to a complex history of host-parasite coevolution, lentiviruses exhibit a high degree of species specificity. Given the well-documented viral archeology of human immunodeficiency virus (HIV) emergence following human exposures to simian immunodeficiency virus (SIV), an understanding of processes that promote successful cross-species lentiviral transmissions is highly relevant. We previously reported natural cross-species transmission of a subtype of feline immunodeficiency virus, puma lentivirus A (PLVA), between bobcats ( Lynx rufus ) and mountain lions ( Puma concolor ) for a small number of animals in California and Florida. In this study, we investigate host-specific selection pressures, within-host viral fitness, and inter- versus intraspecies transmission patterns among a larger collection of PLV isolates from free-ranging bobcats and mountain lions. Analyses of proviral and viral RNA levels demonstrate that PLVA fitness is severely restricted in mountain lions compared to that in bobcats. We document evidence of diversifying selection in three of six PLVA genomes from mountain lions, but we did not detect selection among 20 PLVA isolates from bobcats. These findings support the hypothesis that PLVA is a bobcat-adapted virus which is less fit in mountain lions and under intense selection pressure in the novel host. Ancestral reconstruction of transmission events reveals that intraspecific PLVA transmission has occurred among panthers ( Puma concolor coryi ) in Florida following the initial cross-species infection from bobcats. In contrast, interspecific transmission from bobcats to mountain lions predominates in California. These findings document outcomes of cross-species lentiviral transmission events among felids that compare to the emergence of HIV from nonhuman primates. IMPORTANCE Cross-species transmission episodes can be singular, dead-end events or can result in viral replication and spread in the new species. The factors that determine which

  2. Heavy metals in fish from the Aleutians: Interspecific and locational differences

    International Nuclear Information System (INIS)

    Burger, Joanna; Gochfeld, Michael; Jeitner, Christian; Pittfield, Taryn; Donio, Mark

    2014-01-01

    The objectives of this study were to examine levels of arsenic, cadmium, lead, mercury and selenium in edible tissue of seven species of marine fish collected from several Aleutian islands (in 2004) to determine: (1) interspecific differences, (2) locational differences (among Aleutian Islands), (3) size-related differences in any metal levels within a species, and (4) potential risk to the fish or to predators on the fish, including humans. We also compared metals levels to those of three other fish species previously examined in detail, as well as examining metals in the edible tissue of octopus (Octopus dofleini). Octopus did not have the highest levels of any metal. There were significant interspecific differences in all metal levels among the fish species, although the differences were less than an order of magnitude, except for arsenic (mean of 19,500 ppb in Flathead sole, Hippoglossoides elassodon). Significant intraisland variation occurred among the four sites on Amchitka, but there was not a consistent pattern. There were significant interisland differences for some metals and species. Mercury levels increased significantly with size for several species; lead increased significantly for only one fish species; and cadmium and selenium decreased significantly with size for halibut (Hippoglossus stenolepis). The Alaskan Department of Health and Social Services supports unrestricted consumption of most Alaskan fish species for all people, including pregnant women. Most mean metal concentrations were well below the levels known to adversely affect the fish themselves, or predators that consume them (including humans), except for mercury in three fish species (mean levels just below 0.3 ppm), and arsenic in two fish species. However, even at low mercury levels, people who consume fish almost daily will exceed guideline values from the Centers for Disease Control and the Environmental Protection Agency. - Highlights: • Cadmium, lead, mercury and selenium

  3. Heavy metals in fish from the Aleutians: Interspecific and locational differences

    Energy Technology Data Exchange (ETDEWEB)

    Burger, Joanna, E-mail: burger@biology.rutgers.edu [Division of Life Sciences, Rutgers University, 604 Allison Road, Piscataway, NJ (United States); Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, NJ (United States); Consortium for Risk Evaluation with Stakeholder Participation, Vanderbilt University, Nashville, TN 37235 (United States); Gochfeld, Michael [Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, NJ (United States); Consortium for Risk Evaluation with Stakeholder Participation, Vanderbilt University, Nashville, TN 37235 (United States); Environmental and Occupational Medicine, Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ 08854 (United States); Jeitner, Christian; Pittfield, Taryn [Division of Life Sciences, Rutgers University, 604 Allison Road, Piscataway, NJ (United States); Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, NJ (United States); Consortium for Risk Evaluation with Stakeholder Participation, Vanderbilt University, Nashville, TN 37235 (United States); Donio, Mark [Division of Life Sciences, Rutgers University, 604 Allison Road, Piscataway, NJ (United States)

    2014-05-01

    The objectives of this study were to examine levels of arsenic, cadmium, lead, mercury and selenium in edible tissue of seven species of marine fish collected from several Aleutian islands (in 2004) to determine: (1) interspecific differences, (2) locational differences (among Aleutian Islands), (3) size-related differences in any metal levels within a species, and (4) potential risk to the fish or to predators on the fish, including humans. We also compared metals levels to those of three other fish species previously examined in detail, as well as examining metals in the edible tissue of octopus (Octopus dofleini). Octopus did not have the highest levels of any metal. There were significant interspecific differences in all metal levels among the fish species, although the differences were less than an order of magnitude, except for arsenic (mean of 19,500 ppb in Flathead sole, Hippoglossoides elassodon). Significant intraisland variation occurred among the four sites on Amchitka, but there was not a consistent pattern. There were significant interisland differences for some metals and species. Mercury levels increased significantly with size for several species; lead increased significantly for only one fish species; and cadmium and selenium decreased significantly with size for halibut (Hippoglossus stenolepis). The Alaskan Department of Health and Social Services supports unrestricted consumption of most Alaskan fish species for all people, including pregnant women. Most mean metal concentrations were well below the levels known to adversely affect the fish themselves, or predators that consume them (including humans), except for mercury in three fish species (mean levels just below 0.3 ppm), and arsenic in two fish species. However, even at low mercury levels, people who consume fish almost daily will exceed guideline values from the Centers for Disease Control and the Environmental Protection Agency. - Highlights: • Cadmium, lead, mercury and selenium

  4. Parrotfish grazing ability: interspecific differences in relation to jaw-lever mechanics and relative weight of adductor mandibulae on an Okinawan coral reef

    OpenAIRE

    Nanami, Atsushi

    2016-01-01

    Parrotfishes (family Labridae: Scarini) are regarded to have important roles for maintaining the ecosystem balance in coral reefs due to their removal of organic matter and calcic substrates by grazing. The purpose of the present study was to clarify the interspecific differences in grazing ability of five parrotfish species (Chlorurus sordidus, C. bowersi, Scarus rivulatus, S. niger and S. forsteni) in relation to interspecific differences in jaw-lever mechanics and the relative weight of th...

  5. Interspecific competition changes photosynthetic and oxidative stress response of barley and barnyard grass to elevated CO2 and temperature

    OpenAIRE

    Irena Januskaitiene; Jūratė Žaltauskaitė; Austra Dikšaitytė; Gintarė Sujetovienė; Diana Miškelytė; Giedrė Kacienė; Sandra Sakalauskienė; Jurga Miliauskienė; Romualdas Juknys

    2018-01-01

    This work focuses on the investigation of competition interaction between C3 crop barley (Hordeum vulgare L.) and C4 weed barnyard grass (Echinochloa crus-galli L.) at 2 times higher than ambient [CO2] and +4 0C higher ambient temperature climate conditions. It was hypothesized that interspecific competition will change the response of the investigated plants to increased [CO2] and temperature. The obtained results showed that in the current climate conditions, a higher biomass and photosynth...

  6. Niche filtering, not interspecific resource competition, explains the co-occurrence of butterfly species across the Japanese archipelago

    OpenAIRE

    Iwasaki, Takaya; Sato, Yasuhiro; Nakadai, Ryosuke; Hashimoto, Koya

    2017-01-01

    The relevance of interspecific resource competition in the context of community assembly by herbivorous insects is a well-known topic in ecology. Most previous studies focused on local species assemblies, that shared host plants. Few studies evaluated species pairs within a single taxon when investigating the effects of host plant sharing at the regional scale. Herein, we explore the effect of plant sharing on the geographical co-occurrence patterns of 229 butterflies distributed across the J...

  7. Variation in foraging behavior and body mass in broods of Emperor Geese (Chen canagica): Evidence for interspecific density dependence

    Science.gov (United States)

    Schmutz, J.A.; Laing, K.K.

    2002-01-01

    Broods of geese spend time feeding according to availability and quality of food plants, subject to inherent foraging and digestive constraints. We studied behavioral patterns of broods of Emperor Geese (Chen canagica) on the Yukon–Kuskokwim Delta, Alaska, and examined how feeding and alert behavior varied in relation to habitat and goose density. During 1994–1996, time spent feeding by Emperor Goose goslings and adult females was positively related to multispecies goose densities near observation blinds, and not to just Emperor Goose density. Similarly, body mass of Emperor Goose goslings was more strongly related (negatively) to multispecies goose densities than intraspecific densities. A grazing experiment in 1995 indicated that most above ground primary production by Carex subspathacea, a preferred food plant, was consumed by grazing geese. Those results demonstrate that interspecific competition for food occurred, with greatest support for goslings whose behavioral repertoire is limited primarily to feeding, digesting, and resting. Although the more abundant Cackling Canada Geese (Branta canadensis minima) differed from Emperor Geese in their preferred use of habitats during brooding rearing (Schmutz 2001), the two species occurred in equal abundance in habitats preferred by Emperor Goose broods. Thus, Cackling Canada Geese were a numerically significant competitor with Emperor Geese. Comparing these results to an earlier study, time spent feeding by goslings, adult females, and adult males were greater during 1993–1996 than during 1985–1986. During the interval between those studies, densities of Cackling Canada Geese increased two to three times whereas Emperor Goose numbers remained approximately stable, which implies that interspecific competition affected foraging behavior over a long time period. These density-dependent changes in foraging behavior and body mass indicate that interspecific competition affects nutrient acquisition and gosling

  8. Importance of intra- and interspecific plant interactions for the phytomanagement of semiarid mine tailings using the tree species Pinus halepensis.

    Science.gov (United States)

    Martinez-Oró, Duli; Parraga-Aguado, Isabel; Querejeta, Jose Ignacio; Conesa, Héctor M

    2017-11-01

    The objective of this work was to evaluate the effects of plant interactions (intra- and interspecific) on the growth and metal(loid) uptake of the tree species Pinus halepensis to determine its suitability for the phytomanagement of semiarid mine tailings. The pioneer tailings colonizer grass Piptatherum miliaceum was selected for assessing interspecific interactions. The experiment was conducted following a pot experimental design employing mine tailings soil. Pots containing single individuals of P. halepensis or P. miliaceum and pots containing combinations with pines (two pines per pot, or one pine and one grass per pot) were used. The analyses included the determination of plant biomass, foliar element status and stable isotope composition, metal(loid) uptake and its translocation to different plant organs. P. halepensis strongly favoured the growth of P. miliaceum by increasing 9-fold the latter's biomass and alleviating its P limitation. In this interspecific treatment P. halepensis showed a strong N limitation (N/P = 7), which negatively affected its growth, (to about half the biomass of that obtained for the other treatments) and exhibited a significant increase in some metals translocation (especially Cd) into aerial parts. Interestingly, P. miliaceum showed a decrease in the root to leaves translocation factor for most of metals when growing together with pines. The effects of the intraespecific combination on growth and metal uptake in P. halepensis were less relevant than those obtained for the interspecific one. Further research should be focused on testing the behaviour of plant co-cultures under the addition of N or P amendments which could alleviate the negative effects of plant competition. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Interspecific interactions between Phragmites australis and Spartina alterniflora along a tidal gradient in the Dongtan wetland, Eastern China.

    Directory of Open Access Journals (Sweden)

    Yue Yuan

    Full Text Available The invasive species Spartina alterniora Loisel was introduced to the eastern coast of China in the 1970s and 1980s for the purposes of land reclamation and the prevention of soil erosion. The resulting interspecific competition had an important influence on the distribution of native vegetation, which makes studying the patterns and mechanisms of the interactions between Spartina alterniora Loisel and the native species Phragmites australis (Cav. Trin ex Steud in this region very important. There have been some researches on the interspecific interactions between P. australis and S. alterniora in the Dongtan wetland of Chongming, east China, most of which has focused on the comparison of their physiological characteristics. In this paper, we conducted a neighbor removal experiment along a tidal gradient to evaluate the relative competitive abilities of the two species by calculating their relative neighbor effect (RNE index. We also looked at the influence of environmental stress and disturbance on the competitive abilities of the two species by comparing interaction strength (I among different tidal zones both for P. australis and S. alterniora. Finally, we measured physiological characteristics of the two species to assess the physiological mechanisms behind their different competitive abilities. Both negative and positive interactions were found between P. australis and S. alterniora along the environmental gradient. When the direction of the competitive intensity index for P. australis and S. alterniora was consistent, the competitive or facilitative effect of S. alterniora on P. australis was stronger than that of P. australis on S. alterniora. The interspecific interactions of P. australis and S. alterniora varied with environmental conditions, as well as with the method used, to measure interspecific interactions.

  10. Incongruence between morphotypes and genetically delimited species in the coral genus Stylophora: phenotypic plasticity, morphological convergence, morphological stasis or interspecific hybridization?

    Directory of Open Access Journals (Sweden)

    Flot Jean-François

    2011-10-01

    Full Text Available Abstract Background Morphological data suggest that, unlike most other groups of marine organisms, scleractinian corals of the genus Stylophora are more diverse in the western Indian Ocean and in the Red Sea than in the central Indo-Pacific. However, the morphology of corals is often a poor predictor of their actual biodiversity: hence, we conducted a genetic survey of Stylophora corals collected in Madagascar, Okinawa, the Philippines and New Caledonia in an attempt to find out the true number of species in these various locations. Results A molecular phylogenetic analysis of the mitochondrial ORF and putative control region concurs with a haploweb analysis of nuclear ITS2 sequences in delimiting three species among our dataset: species A and B are found in Madagascar whereas species C occurs in Okinawa, the Philippines and New Caledonia. Comparison of ITS1 sequences from these three species with data available online suggests that species C is also found on the Great Barrier Reef, in Malaysia, in the South China Sea and in Taiwan, and that a distinct species D occurs in the Red Sea. Shallow-water morphs of species A correspond to the morphological description of Stylophora madagascarensis, species B presents the morphology of Stylophora mordax, whereas species C comprises various morphotypes including Stylophora pistillata and Stylophora mordax. Conclusions Genetic analysis of the coral genus Stylophora reveals species boundaries that are not congruent with morphological traits. Of the four hypotheses that may explain such discrepancy (phenotypic plasticity, morphological stasis, morphological convergence, and interspecific hybridization, the first two appear likely to play a role but the fourth one is rejected since mitochondrial and nuclear markers yield congruent species delimitations. The position of the root in our molecular phylogenies suggests that the center of origin of Stylophora is located in the western Indian Ocean, which probably

  11. Interspecific competition changes photosynthetic and oxidative stress response of barley and barnyard grass to elevated CO2 and temperature

    Directory of Open Access Journals (Sweden)

    Irena Januskaitiene

    2018-03-01

    Full Text Available This work focuses on the investigation of competition interaction between C3 crop barley (Hordeum vulgare L. and C4 weed barnyard grass (Echinochloa crus-galli L. at 2 times higher than ambient [CO2] and +4 0C higher ambient temperature climate conditions. It was hypothesized that interspecific competition will change the response of the investigated plants to increased [CO2] and temperature. The obtained results showed that in the current climate conditions, a higher biomass and photosynthetic rate and a lower antioxidant activity were detected for barley grown under interspecific competition effect. While in the warmed climate and under competition conditions opposite results were detected: a higher water use efficiency, a higher photosynthetic performance, a lower dissipated energy flux and a lower antioxidant enzymes activity were detected for barnyard grass plants. This study highlights that in the future climate conditions, barnyard grass will become more efficient in performance of the photosynthetic apparatus and it will suffer from lower oxidative stress caused by interspecific competition as compared to barley.

  12. Body mass of prefledging Emperor Geese Chen canagica: Large-scale effects of interspecific densities and food availability

    Science.gov (United States)

    Lake, B.C.; Schmutz, J.A.; Lindberg, M.S.; Ely, Craig R.; Eldridge, W.D.; Broerman, F.J.

    2008-01-01

    We studied body mass of prefledging Emperor Geese Chen canagica at three locations across the Yukon-Kuskokwim Delta, Alaska, during 1990-2004 to investigate whether large-scale variation in body mass was related to interspecific competition for food. From 1990 to 2004, densities of Cackling Geese Branta hutchinsii minima more than doubled and were c. 2-5?? greater than densities of Emperor Geese, which were relatively constant over time. Body mass of prefledging Emperor Geese was strongly related (negatively) to interspecific densities of geese (combined density of Cackling and Emperor Geese) and positively related to measures of food availability (grazing lawn extent and net above-ground primary productivity (NAPP)). Grazing by geese resulted in consumption of ??? 90% of the NAPP that occurred in grazing lawns during the brood-rearing period, suggesting that density-dependent interspecific competition was from exploitation of common food resources. Efforts to increase the population size of Emperor Geese would benefit from considering competitive interactions among goose species and with forage plants. ?? 2008 The Authors.

  13. Assessment of interspecific interactions in plant communities: an illustration from the cold desert saltbush grasslands of North America

    Science.gov (United States)

    Freeman, Carl D.; Emlen, John M.

    1995-01-01

    Interspecific interactions influence both the productivity and composition of plant communities. Here, we propose new field procedures and analytical approaches for assessing interspecific interactions in nature and apply these procedures to the salt desert shrub grasslands of western Utah. Data were collected from two grazing treatments over a period of 2 years. The proposed equations were fairly consistent across both treatments and years. In addition to illustrating how to assess interspecific interactions within a community, we also develop a new approach for projecting the community composition as a result of some alteration, i.e. increase or decrease in the abundance of one or more species. Results demonstrate competition both within and between plant life-form groups. While introduced annuals were found to depress profoundly the likelihood of perennial plants replacing themselves, perennials had little influence on annuals. Thus, as native perennials die, they are more likely to be replaced by perennials than for the reverse to occur. Our results suggest that unless conditions change, these communities will become increasingly dominated by introduced annuals.

  14. Converse Barrier Certificate Theorems

    DEFF Research Database (Denmark)

    Wisniewski, Rafael; Sloth, Christoffer

    2016-01-01

    This paper shows that a barrier certificate exists for any safe dynamical system. Specifically, we prove converse barrier certificate theorems for a class of structurally stable dynamical systems. Other authors have developed a related result by assuming that the dynamical system has neither...

  15. Traditional and cyberbullying victimization as correlates of psychosocial distress and barriers to a healthy lifestyle among severely obese adolescents – a matched case–control study on prevalence and results from a cross-sectional study

    Science.gov (United States)

    2014-01-01

    Background Obese youth are at increased risk for peer victimization, which may heighten their risk of psychosocial problems and physical activity avoidance, and lower the effectiveness of professional and lifestyle weight-loss initiatives. Little is known about obese adolescents’ risk for victimization from cyber-bullying and how this relates to psychosocial functioning and healthy lifestyle barriers. The purpose of the study was to assess traditional and cyber-victimization among adolescents with severe obesity and its relation to psychosocial distress and barriers to healthy lifestyles. Methods A sample of 102 obese adolescents (mean age = 15.32 ±1.71) in residential treatment was matched with 102 normal-weight youngsters from the Health Behavior in School-aged Children (HBSC) study (mean age = 15.30 ±1.73). Results Adolescents with obesity were significantly more often cyber-victimized than normal-weight peers. Obese youth victimized by traditional bullying experienced lower quality of life, lower motivation for physical activity and higher avoidance and emotional coping towards healthy lifestyles than those non-victimized. Obese cyber-victims experienced significantly higher suicidal ideation. Conclusions Traditional and cyber-victimization may hinder treatment effectiveness and healthy lifestyle change in adolescents with obesity. Health professionals should pro-actively address peer victimization and psychosocial functioning during multidisciplinary obesity treatment. Schools could contribute to a better physical and psychosocial health of obese youth by implementing multi-behavioral health-promotion programs. PMID:24593118

  16. Traditional and cyberbullying victimization as correlates of psychosocial distress and barriers to a healthy lifestyle among severely obese adolescents--a matched case-control study on prevalence and results from a cross-sectional study.

    Science.gov (United States)

    DeSmet, Ann; Deforche, Benedicte; Hublet, Anne; Tanghe, Ann; Stremersch, Evi; De Bourdeaudhuij, Ilse

    2014-03-05

    Obese youth are at increased risk for peer victimization, which may heighten their risk of psychosocial problems and physical activity avoidance, and lower the effectiveness of professional and lifestyle weight-loss initiatives. Little is known about obese adolescents' risk for victimization from cyber-bullying and how this relates to psychosocial functioning and healthy lifestyle barriers. The purpose of the study was to assess traditional and cyber-victimization among adolescents with severe obesity and its relation to psychosocial distress and barriers to healthy lifestyles. A sample of 102 obese adolescents (mean age=15.32±1.71) in residential treatment was matched with 102 normal-weight youngsters from the Health Behavior in School-aged Children (HBSC) study (mean age=15.30±1.73). Adolescents with obesity were significantly more often cyber-victimized than normal-weight peers. Obese youth victimized by traditional bullying experienced lower quality of life, lower motivation for physical activity and higher avoidance and emotional coping towards healthy lifestyles than those non-victimized. Obese cyber-victims experienced significantly higher suicidal ideation. Traditional and cyber-victimization may hinder treatment effectiveness and healthy lifestyle change in adolescents with obesity. Health professionals should pro-actively address peer victimization and psychosocial functioning during multidisciplinary obesity treatment. Schools could contribute to a better physical and psychosocial health of obese youth by implementing multi-behavioral health-promotion programs.

  17. Skin barrier function

    DEFF Research Database (Denmark)

    2016-01-01

    Renowned experts present the latest knowledge Although a very fragile structure, the skin barrier is probably one of the most important organs of the body. Inward/out it is responsible for body integrity and outward/in for keeping microbes, chemicals, and allergens from penetrating the skin. Since...... the role of barrier integrity in atopic dermatitis and the relationship to filaggrin mutations was discovered a decade ago, research focus has been on the skin barrier, and numerous new publications have become available. This book is an interdisciplinary update offering a wide range of information...... on the subject. It covers new basic research on skin markers, including results on filaggrin and on methods for the assessment of the barrier function. Biological variation and aspects of skin barrier function restoration are discussed as well. Further sections are dedicated to clinical implications of skin...

  18. Barriers to the future

    Energy Technology Data Exchange (ETDEWEB)

    Massey, C T

    1986-09-01

    Opportunities for the British coal industry seem vast yet there are still barriers to progress. Seven areas are identified and discussed: mining mobility (for example, longwall mining systems are rigid and inflexible compared with American stall and pillar working); mine structure (many mines are more suitable to pit ponies than to large pieces of equipment); financial barriers (Government requires the industry to break even in 1987/88); personnel barriers (less specialization, better use of skills); safety barriers (increased use of remote control, ergonomics and robotics to protect workers); microelectronic management (nationalization has cushioned management from the market place; there is a need for a more multidisciplinary approach to the industry); and legal barriers (most legislation in the past has been in response to accidents; legislation external to the industry but affecting it is more fundamental).

  19. Fusion barrier distributions and fission anisotropies

    International Nuclear Information System (INIS)

    Hinde, D.J.; Morton, C.R.; Dasgupta, M.; Leigh, J.R.; Lestone, J.P.; Lemmon, R.C.; Mein, J.C.; Newton, J.O.; Timmers, H.; Rowley, N.; Kruppa, A.T.

    1995-01-01

    Fusion excitation functions for 16,17 O+ 144 Sm have been measured to high precision. The extracted fusion barrier distributions show a double-peaked structure interpreted in terms of coupling to inelastic collective excitations of the target. The effect of the positive Q-value neutron stripping channel is evident in the reaction with 17 O. Fission and evaporation residue cross-sections and excitation functions have been measured for the reaction of 16 O+ 208 Pb and the fusion barrier distribution and fission anisotropies determined. It is found that the moments of the fusion l-distribution determined from the fusion and fission measurements are in good agreement. ((orig.))

  20. Interspecific variation in the phenology of advertisement calling in a temperate Australian frog community.

    Science.gov (United States)

    Heard, Geoffrey W; Canessa, Stefano; Parris, Kirsten M

    2015-09-01

    Spatial and temporal partitioning of resources underlies the coexistence of species with similar niches. In communities of frogs and toads, the phenology of advertisement calling provides insights into temporal partitioning of reproductive effort and its implications for community dynamics. This study assessed the phenology of advertisement calling in an anuran community from Melbourne, in southern Australia. We collated data from 1432 surveys of 253 sites and used logistic regression to quantify seasonality in the nightly probability of calling and the influence of meteorological variables on this probability for six species of frogs. We found limited overlap in the predicted seasonal peaks of calling among these species. Those shown to have overlapping calling peaks are unlikely to be in direct competition, due to differences in larval ecology (Crinia signifera and Litoria ewingii) or differences in calling behavior and acoustics (Limnodynastes dumerilii and Litoria raniformis). In contrast, closely related and ecologically similar species (Crinia signfera and Crinia parinsignifera;Litoria ewingii and Litoria verreauxii) appear to have staggered seasonal peaks of calling. In combination with interspecific variation in the meteorological correlates of calling, these results may be indicative of temporal partitioning of reproductive activity to facilitate coexistence, as has been reported for tropical and temperate anurans from other parts of the globe.

  1. Meiosis in elephant grass (Pennisetum purpureum, pearl millet (Pennisetum glaucum (Poaceae, Poales and their interspecific hybrids

    Directory of Open Access Journals (Sweden)

    Vânia Helena Techio

    2006-01-01

    Full Text Available The cultivated and sexually compatible species Pennisetum purpureum (elephant grass, 2n = 4x = 28 and Pennisetum glaucum (pearl millet, 2n = 2x = 14 can undergo hybridization which favors the amplification of their genetic background and the introgression of favorable alleles into breeding programs. The main problem with interspecific hybrids of these species is infertility due to triploidy (2n = 3x = 21. This study describes meiosis in elephant grass x pearl millet hybrids and their progenitors. Panicles were prepared according to the conventional protocol for meiotic studies and Alexander’s stain was used for assessing pollen viability. Pearl millet accessions presented regular meiosis with seven bivalents and high pollen viability. For elephant grass, 14 bivalents in diakinesis and metaphase I were observed. The BAG 63 elephant grass accession, derived from tissue culture, presented a high frequency of meiotic abnormalities. The three hybrid accessions presented a high frequency of abnormalities characterized by irregular chromosomal segregation which resulted in the formation of sterile pollen.

  2. Newly generated interspecific wine yeast hybrids introduce flavour and aroma diversity to wines.

    Science.gov (United States)

    Bellon, Jennifer R; Eglinton, Jeffery M; Siebert, Tracey E; Pollnitz, Alan P; Rose, Louisa; de Barros Lopes, Miguel; Chambers, Paul J

    2011-08-01

    Increasingly, winemakers are looking for ways to introduce aroma and flavour diversity to their wines as a means of improving style and increasing product differentiation. While currently available commercial yeast strains produce consistently sound fermentations, there are indications that sensory complexity and improved palate structure are obtained when other species of yeast are active during fermentation. In this study, we explore a strategy to increase the impact of non-Saccharomyces cerevisiae inputs without the risks associated with spontaneous fermentations, through generating interspecific hybrids between a S. cerevisiae wine strain and a second species. For our experiments, we used rare mating to produce hybrids between S. cerevisiae and other closely related yeast of the Saccharomyces sensu stricto complex. These hybrid yeast strains display desirable properties of both parents and produce wines with concentrations of aromatic fermentation products that are different to what is found in wine made using the commercial wine yeast parent. Our results demonstrate, for the first time, that the introduction of genetic material from a non-S. cerevisiae parent into a wine yeast background can impact favourably on the wine flavour and aroma profile of a commercial S. cerevisiae wine yeast.

  3. Meta-analysis of the effects of forest fragmentation on interspecific interactions.

    Science.gov (United States)

    Magrach, Ainhoa; Laurance, William F; Larrinaga, Asier R; Santamaria, Luis

    2014-10-01

    Forest fragmentation dramatically alters species persistence and distribution and affects many ecological interactions among species. Recent studies suggest that mutualisms, such as pollination and seed dispersal, are more sensitive to the negative effects of forest fragmentation than antagonisms, such as predation or herbivory. We applied meta-analytical techniques to evaluate this hypothesis and quantified the relative contributions of different components of the fragmentation process (decreases in fragment size, edge effects, increased isolation, and habitat degradation) to the overall effect. The effects of fragmentation on mutualisms were primarily driven by habitat degradation, edge effects, and fragment isolation, and, as predicted, they were consistently more negative on mutualisms than on antagonisms. For the most studied interaction type, seed dispersal, only certain components of fragmentation had significant (edge effects) or marginally significant (fragment size) effects. Seed size modulated the effect of fragmentation: species with large seeds showed stronger negative impacts of fragmentation via reduced dispersal rates. Our results reveal that different components of the habitat fragmentation process have varying impacts on key mutualisms. We also conclude that antagonistic interactions have been understudied in fragmented landscapes, most of the research has concentrated on particular types of mutualistic interactions such as seed dispersal, and that available studies of interspecific interactions have a strong geographical bias (arising mostly from studies carried out in Brazil, Chile, and the United States). © 2014 Society for Conservation Biology.

  4. Pesticide-mediated interspecific competition between local and invasive thrips pests

    Science.gov (United States)

    Zhao, Xueyin; Reitz, Stuart R.; Yuan, Huiguo; Lei, Zhongren; Paini, Dean Ronald; Gao, Yulin

    2017-01-01

    Competitive interactions between species can be mitigated or even reversed in the presence of anthropogenic influences. The thrips species Frankliniella occidentalis and Thrips tabaci are highly invasive and damaging agricultural pests throughout the world. Where the species co-occur, one species tends to eventually predominate over the other. Avermectin and beta-cypermethrin are commonly used insecticides to manage thrips in China, and laboratory bioassays demonstrated that F. occidentalis is significantly less susceptible than T. tabaci to these insecticides. In laboratory cage trials in which both species were exposed to insecticide treated cabbage plants, F. occidentalis became the predominant species. In contrast, T. tabaci completely displaced F. occidentalis on plants that were not treated with insecticides. In field trials, the species co-existed on cabbage before insecticide treatments began, but with T. tabaci being the predominant species. Following application of avermectin or beta-cypermethrin, F. occidentalis became the predominant species, while in plots not treated with insecticides, T. tabaci remained the predominant species. These results indicate that T. tabaci is an intrinsically superior competitor to F. occidentalis, but its competitive advantage can be counteracted through differential susceptibilities of the species to insecticides. These results further demonstrate the importance of external factors, such as insecticide applications, in mediating the outcome of interspecific interactions and produce rapid unanticipated shifts in the demographics of pest complexes. PMID:28084404

  5. Interspecific variation of total seed protein in wild rice germplasm using SDS-Page

    International Nuclear Information System (INIS)

    Shah, S.M.A.; Hidayat-ur-Rahman; Abbasi, F.M.; Ashiq, M.; Rabbani, A.M.; Khan, I.A.; Shinwari, Z.K.; Shah, Z.

    2011-01-01

    Variation in seed protein of 14 wild rice species (Oryza spp.) along with cultivated rice species (O. sativa) was studied using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) to assess genetic diversity in the rice germplasm. SDS bands were scored as present (1) or absent (0) for protein sample of each genotype. On the basis of cluster analysis, four clusters were identified at a similarity level of 0.85. O. nivara, O. rufipogon and O. sativa with AA genomes constituted the first cluster. The second cluster comprised O. punctata of BB genome and wild rice species of CC genome i.e., O. rhizomatis and O. officinalis. However, it also contained O. barthii and O. glumaepatula of AA genome. O. australiensis with EE genome, and O. latifolia, O. alta and O. grandiglumis having CCDD genomes comprised the third cluster. The fourth cluster consisted of wild rice species, O. brachyantha with EE genome along with two other wild rice species, O. longistaminata and O. meridionalis of AA genome. Overall, on the basis of total seed protein, the grouping pattern of rice genotypes was mostly compatible with their genome status. The results of the present work depicted considerable interspecific genetic variation in the investigated germplasm for total seed protein. Moreover, the results obtained in this study also suggest that analysis of seed protein can also provide a better understanding of genetic affinity of the germplasm. (author)

  6. Interspecific shared collective decision-making in two forensically important species.

    Science.gov (United States)

    Boulay, Julien; Deneubourg, Jean-Louis; Hédouin, Valéry; Charabidzé, Damien

    2016-02-10

    To date, the study of collective behaviour has mainly focused on intraspecific situations: the collective decision-making of mixed-species groups involving interspecific aggregation-segregation has received little attention. Here, we show that, in both conspecific and heterospecific groups, the larvae of two species (Lucilia sericata and Calliphora vomitoria, calliphorid carrion-feeding flies) were able to make a collective choice. In all groups, the choice was made within a few minutes and persisted throughout the period of the experiment. The monitoring of a focal individual within a group showed that these aggregations were governed by attractive and retentive effects of the group. Furthermore, the similarity observed between the conspecific and heterospecific groups suggested the existence of shared aggregation signals. The group size was found to have a stronger influence than the species of necrophagous larvae. These results should be viewed in relation to the well-known correlation between group size and heat generation. This study provides the first experimental examination of the dynamics of collective decision-making in mixed-species groups of invertebrates, contributing to our understanding of the cooperation-competition phenomenon in animal social groups. © 2016 The Author(s).

  7. Widespread evidence for interspecific mating between Aedes aegypti and Aedes albopictus (Diptera: Culicidae) in nature.

    Science.gov (United States)

    Bargielowski, I E; Lounibos, L P; Shin, D; Smartt, C T; Carrasquilla, M C; Henry, A; Navarro, J C; Paupy, C; Dennett, J A

    2015-12-01

    Aedes aegypti and Aedes albopictus, two important vectors of the dengue and chikungunya viruses to humans, often come in contact in their invasive ranges. In these circumstances, a number of factors are thought to influence their population dynamics, including resource competition among the larval stages, prevailing environmental conditions and reproductive interference in the form of satyrization. As the distribution and abundance of Ae. aegypti and Ae. albopictus have profound epidemiological implications, understanding the competitive interactions that influence these patterns in nature is important. While evidence for resource competition and environmental factors had been gathered from the field, the evidence for reproductive interference, though strongly inferred through laboratory trials, remained sparse (one small-scale field trial). In this paper we demonstrate that low rates (1.12-3.73%) of interspecific mating occur in nature among populations of these species that have co-existed sympatrically from 3 to 150yrs. Finally this report contributes a new species-specific primer set for identifying the paternity of sperm extracted from field collected specimens. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Global warming increases the interspecific competitiveness of the invasive plant alligator weed, Alternanthera philoxeroides.

    Science.gov (United States)

    Wu, Hao; Ismail, Mohannad; Ding, Jianqing

    2017-01-01

    Global warming could accelerate the spread of invasive species to higher latitudes and intensify their effects on native species. Here, we report results of two years of field surveys along a latitudinal gradient (21°N to 31°N) in southern China, to determine the species structure of the invasive plant Alternanthera philoxeroides community. We also performed a replacement series experiment (mono and mixed) to evaluate the effects of elevated temperature on the competitiveness of A. philoxeroides with the native co-occurring species Digitaria sanguinalis. In the field survey, we found that the dominance of A. philoxeroides increased with increasing of latitude gradient while cover of D. sanguinalis decreased. In monospecific plantings, artificial warming reduced the length of D. sanguinalis roots. In mixed plantings, warming reduced both A. philoxeroides abundance and D. sanguinalis stem length when A. philoxeroides was more prevalent in the planting. Warming also significantly reduced D. sanguinalis biomass, but increased that of A. philoxeroides. In addition, elevated temperatures significantly reduced the relative yield (RY) of D. sanguinalis, particularly when A. philoxeroides was planted in higher proportion in the plot. These results suggest that the invasiveness of A. philoxeroides increased with increasing latitude, and that warming may increase the effectiveness of its interspecific competition with D. sanguinalis. Hence, under global warming conditions, the harm to native species from A. philoxeroides would increase at higher latitudes. Our findings are critical for predicting the invasiveness of alien species under climate change. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Climate and foraging mode explain interspecific variation in snake metabolic rates.

    Science.gov (United States)

    Dupoué, Andréaz; Brischoux, François; Lourdais, Olivier

    2017-11-29

    The energy cost of self-maintenance is a critical facet of life-history strategies. Clarifying the determinant of interspecific variation in metabolic rate (MR) at rest is important to understand and predict ecological patterns such as species distributions or responses to climatic changes. We examined variation of MR in snakes, a group characterized by a remarkable diversity of activity rates and a wide distribution. We collated previously published MR data ( n = 491 observations) measured in 90 snake species at different trial temperatures. We tested for the effects of metabolic state (standard MR (SMR) versus resting MR (RMR)), foraging mode (active versus ambush foragers) and climate (temperature and precipitation) while accounting for non-independence owing to phylogeny, body mass and thermal dependence. We found that RMR was 40% higher than SMR, and that active foragers have higher MR than species that ambush their prey. We found that MR was higher in cold environments, supporting the metabolic cold adaptation hypothesis. We also found an additive and positive effect of precipitation on MR suggesting that lower MR in arid environments may decrease dehydration and energetic costs. Altogether, our findings underline the complex influences of climate and foraging mode on MR and emphasize the relevance of these facets to understand the physiological impact of climate change. © 2017 The Author(s).

  10. Interspecific Plant Interactions Reflected in Soil Bacterial Community Structure and Nitrogen Cycling in Primary Succession

    Directory of Open Access Journals (Sweden)

    Joseph E. Knelman

    2018-02-01

    Full Text Available Past research demonstrating the importance plant–microbe interactions as drivers of ecosystem succession has focused on how plants condition soil microbial communities, impacting subsequent plant performance and plant community assembly. These studies, however, largely treat microbial communities as a black box. In this study, we sought to examine how emblematic shifts from early successional Alnus viridus ssp. sinuata (Sitka alder to late successional Picea sitchensis (Sitka spruce in primary succession may be reflected in specific belowground changes in bacterial community structure and nitrogen cycling related to the interaction of these two plants. We examined early successional alder-conditioned soils in a glacial forefield to delineate how alders alter the soil microbial community with increasing dominance. Further, we assessed the impact of late-successional spruce plants on these early successional alder-conditioned microbiomes and related nitrogen cycling through a leachate addition microcosm experiment. We show how increasingly abundant alder select for particular bacterial taxa. Additionally, we found that spruce leachate significantly alters the composition of these microbial communities in large part by driving declines in taxa that are enriched by alder, including bacterial symbionts. We found these effects to be spruce specific, beyond a general leachate effect. Our work also demonstrates a unique influence of spruce on ammonium availability. Such insights bolster theory relating the importance of plant–microbe interactions with late-successional plants and interspecific plant interactions more generally.

  11. Interspecific Plant Interactions Reflected in Soil Bacterial Community Structure and Nitrogen Cycling in Primary Succession.

    Science.gov (United States)

    Knelman, Joseph E; Graham, Emily B; Prevéy, Janet S; Robeson, Michael S; Kelly, Patrick; Hood, Eran; Schmidt, Steve K

    2018-01-01

    Past research demonstrating the importance plant-microbe interactions as drivers of ecosystem succession has focused on how plants condition soil microbial communities, impacting subsequent plant performance and plant community assembly. These studies, however, largely treat microbial communities as a black box. In this study, we sought to examine how emblematic shifts from early successional Alnus viridus ssp. sinuata (Sitka alder) to late successional Picea sitchensis (Sitka spruce) in primary succession may be reflected in specific belowground changes in bacterial community structure and nitrogen cycling related to the interaction of these two plants. We examined early successional alder-conditioned soils in a glacial forefield to delineate how alders alter the soil microbial community with increasing dominance. Further, we assessed the impact of late-successional spruce plants on these early successional alder-conditioned microbiomes and related nitrogen cycling through a leachate addition microcosm experiment. We show how increasingly abundant alder select for particular bacterial taxa. Additionally, we found that spruce leachate significantly alters the composition of these microbial communities in large part by driving declines in taxa that are enriched by alder, including bacterial symbionts. We found these effects to be spruce specific, beyond a general leachate effect. Our work also demonstrates a unique influence of spruce on ammonium availability. Such insights bolster theory relating the importance of plant-microbe interactions with late-successional plants and interspecific plant interactions more generally.

  12. Caffeine inheritance in interspecific hybrids of Coffea arabica x Coffea canephora (Gentianales, Rubiaceae

    Directory of Open Access Journals (Sweden)

    Regina H.G. Priolli

    2008-01-01

    Full Text Available Caffeine inheritance was investigated in F2 and BC1F1 generations between Coffea arabica var. Bourbon Vermelho (BV and Coffea canephora var. Robusta 4x (R4x. The caffeine content of seeds and leaves was determined during 2004 and 2005. Microsatellite loci-markers were used to deduce the meiotic pattern of chromosome pairing of tetraploid interspecific hybrids. Genetic analysis indicated that caffeine content in seeds was quantitatively inherited and controlled by genes with additive effects. The estimates of broad-sense heritability of caffeine content in seeds were high for both generations. In coffee leaves, the caffeine content (BSH from the same populations showed transgressive segregants with enhanced levels and high BSH. Segregation of loci-markers in BC1F1 populations showed that the ratios of the gametes genotype did not differ significantly from those expected assuming random associations and tetrasomic inheritance. The results confirm the existence of distinct mechanisms controlling the caffeine content in seeds and leaves, the gene exchange between the C. arabica BV and C. canephora R4x genomes and favorable conditions for improving caffeine content in this coffee population.

  13. Concentration of trace elements in feathers of three Antarctic penguins: Geographical and interspecific differences

    Energy Technology Data Exchange (ETDEWEB)

    Jerez, Silvia [Area de Toxicologia, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, 30100 Murcia (Spain); Motas, Miguel, E-mail: motas@um.es [Area de Toxicologia, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, 30100 Murcia (Spain); Palacios, Maria Jose; Valera, Francisco [Departamento de Ecologia Funcional y Evolutiva, Estacion Experimental de Zonas Aridas, CSIC, Carretera de Sacramento s/n, 04120 La Canada de San Urbano, Almeria (Spain); Cuervo, Jose Javier; Barbosa, Andres [Departamento de Ecologia Funcional y Evolutiva, Estacion Experimental de Zonas Aridas, CSIC, Carretera de Sacramento s/n, 04120 La Canada de San Urbano, Almeria (Spain); Departamento de Ecologia Evolutiva, Museo Nacional de Ciencias Naturales, CSIC, C/Jose Gutierrez Abascal 2, 28006 Madrid (Spain)

    2011-10-15

    Antarctica is often considered as one of the last pristine regions, but it could be affected by pollution at global and local scale. Concentrations of Al, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Cd and Pb were determinated by ICP-MS in feathers (n = 207 individuals) of gentoo, chinstrap and Adelie penguin collected in 8 locations throughout the Antarctic Peninsula (2006-2007). The highest levels of several elements were found in samples from King George Island (8.08, 20.29 and 1.76 {mu}g g{sup -1} dw for Cr, Cu and Pb, respectively) and Deception Island (203.13, 3.26 and 164.26 {mu}g g{sup -1} dw for Al, Mn and Fe, respectively), where probably human activities and large-scale transport of pollutants contribute to increase metal levels. Concentrations of Cr, Mn, Cu, Se or Pb, which are similar to others found in different regions of the world, show that some areas in Antarctica are not utterly pristine. - Highlights: > We study levels of trace elements in feathers of Antarctic penguins. > Eight different rookeries throughout the Antarctic Peninsula were sampled. > Interspecific (gentoo, chinstrap, Adelie) and geographical differences were tested. > Relatively high metal levels were found in areas with major human presence. > Penguin feather can be useful for metals monitoring in the Antarctic environment. - Trace element levels in feathers of three penguin species from the Antarctic Peninsula indicate the presence of pollution in certain locations.

  14. Modeling plant interspecific interactions from experiments with perennial crop mixtures to predict optimal combinations.

    Science.gov (United States)

    Halty, Virginia; Valdés, Matías; Tejera, Mauricio; Picasso, Valentín; Fort, Hugo

    2017-12-01

    The contribution of plant species richness to productivity and ecosystem functioning is a longstanding issue in ecology, with relevant implications for both conservation and agriculture. Both experiments and quantitative modeling are fundamental to the design of sustainable agroecosystems and the optimization of crop production. We modeled communities of perennial crop mixtures by using a generalized Lotka-Volterra model, i.e., a model such that the interspecific interactions are more general than purely competitive. We estimated model parameters -carrying capacities and interaction coefficients- from, respectively, the observed biomass of monocultures and bicultures measured in a large diversity experiment of seven perennial forage species in Iowa, United States. The sign and absolute value of the interaction coefficients showed that the biological interactions between species pairs included amensalism, competition, and parasitism (asymmetric positive-negative interaction), with various degrees of intensity. We tested the model fit by simulating the combinations of more than two species and comparing them with the polycultures experimental data. Overall, theoretical predictions are in good agreement with the experiments. Using this model, we also simulated species combinations that were not sown. From all possible mixtures (sown and not sown) we identified which are the most productive species combinations. Our results demonstrate that a combination of experiments and modeling can contribute to the design of sustainable agricultural systems in general and to the optimization of crop production in particular. © 2017 by the Ecological Society of America.

  15. Life span and reproductive cost explain interspecific variation in the optimal onset of reproduction.

    Science.gov (United States)

    Mourocq, Emeline; Bize, Pierre; Bouwhuis, Sandra; Bradley, Russell; Charmantier, Anne; de la Cruz, Carlos; Drobniak, Szymon M; Espie, Richard H M; Herényi, Márton; Hötker, Hermann; Krüger, Oliver; Marzluff, John; Møller, Anders P; Nakagawa, Shinichi; Phillips, Richard A; Radford, Andrew N; Roulin, Alexandre; Török, János; Valencia, Juliana; van de Pol, Martijn; Warkentin, Ian G; Winney, Isabel S; Wood, Andrew G; Griesser, Michael

    2016-02-01

    Fitness can be profoundly influenced by the age at first reproduction (AFR), but to date the AFR-fitness relationship only has been investigated intraspecifically. Here, we investigated the relationship between AFR and average lifetime reproductive success (LRS) across 34 bird species. We assessed differences in the deviation of the Optimal AFR (i.e., the species-specific AFR associated with the highest LRS) from the age at sexual maturity, considering potential effects of life history as well as social and ecological factors. Most individuals adopted the species-specific Optimal AFR and both the mean and Optimal AFR of species correlated positively with life span. Interspecific deviations of the Optimal AFR were associated with indices reflecting a change in LRS or survival as a function of AFR: a delayed AFR was beneficial in species where early AFR was associated with a decrease in subsequent survival or reproductive output. Overall, our results suggest that a delayed onset of reproduction beyond maturity is an optimal strategy explained by a long life span and costs of early reproduction. By providing the first empirical confirmations of key predictions of life-history theory across species, this study contributes to a better understanding of life-history evolution. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  16. Inter-specific coral chimerism: Genetically distinct multicellular structures associated with tissue loss in Montipora capitata

    Science.gov (United States)

    Work, Thierry M.; Forsman, Zac H.; Szabo, Zoltan; Lewis, Teresa D.; Aeby, Greta S.; Toonen, Robert J.

    2011-01-01

    Montipora white syndrome (MWS) results in tissue-loss that is often lethal to Montipora capitata, a major reef building coral that is abundant and dominant in the Hawai'ian Archipelago. Within some MWS-affected colonies in Kane'ohe Bay, Oahu, Hawai'i, we saw unusual motile multicellular structures within gastrovascular canals (hereafter referred to as invasive gastrovascular multicellular structure-IGMS) that were associated with thinning and fragmentation of the basal body wall. IGMS were in significantly greater densities in coral fragments manifesting tissue-loss compared to paired normal fragments. Mesenterial filaments from these colonies yielded typical M. capitata mitochondrial haplotypes (CO1, CR), while IGMS from the same colony consistently yielded distinct haplotypes previously only found in a different Montipora species (Montipora flabellata). Protein profiles showed consistent differences between paired mesenterial filaments and IGMS from the same colonies as did seven microsatellite loci that also exhibited an excess of alleles per locus inconsistent with a single diploid organism. We hypothesize that IGMS are a parasitic cellular lineage resulting from the chimeric fusion between M. capitata and M. flabellata larvae followed by morphological reabsorption of M. flabellata and subsequent formation of cell-lineage parasites. We term this disease Montiporaiasis. Although intra-specific chimerism is common in colonial animals, this is the first suspected inter-specific example and the first associated with tissue loss.

  17. Pesticide-mediated interspecific competition between local and invasive thrips pests.

    Science.gov (United States)

    Zhao, Xueyin; Reitz, Stuart R; Yuan, Huiguo; Lei, Zhongren; Paini, Dean Ronald; Gao, Yulin

    2017-01-13

    Competitive interactions between species can be mitigated or even reversed in the presence of anthropogenic influences. The thrips species Frankliniella occidentalis and Thrips tabaci are highly invasive and damaging agricultural pests throughout the world. Where the species co-occur, one species tends to eventually predominate over the other. Avermectin and beta-cypermethrin are commonly used insecticides to manage thrips in China, and laboratory bioassays demonstrated that F. occidentalis is significantly less susceptible than T. tabaci to these insecticides. In laboratory cage trials in which both species were exposed to insecticide treated cabbage plants, F. occidentalis became the predominant species. In contrast, T. tabaci completely displaced F. occidentalis on plants that were not treated with insecticides. In field trials, the species co-existed on cabbage before insecticide treatments began, but with T. tabaci being the predominant species. Following application of avermectin or beta-cypermethrin, F. occidentalis became the predominant species, while in plots not treated with insecticides, T. tabaci remained the predominant species. These results indicate that T. tabaci is an intrinsically superior competitor to F. occidentalis, but its competitive advantage can be counteracted through differential susceptibilities of the species to insecticides. These results further demonstrate the importance of external factors, such as insecticide applications, in mediating the outcome of interspecific interactions and produce rapid unanticipated shifts in the demographics of pest complexes.

  18. Naked Mole Rat Induced Pluripotent Stem Cells and Their Contribution to Interspecific Chimera

    Directory of Open Access Journals (Sweden)

    Sang-Goo Lee

    2017-11-01

    Full Text Available Naked mole rats (NMRs are exceptionally long-lived, cancer-resistant rodents. Identifying the defining characteristics of these traits may shed light on aging and cancer mechanisms. Here, we report the generation of induced pluripotent stem cells (iPSCs from NMR fibroblasts and their contribution to mouse-NMR chimeric embryos. Efficient reprogramming could be observed under N2B27+2i conditions. The iPSCs displayed a characteristic morphology, expressed pluripotent markers, formed embryoid bodies, and showed typical differentiation patterns. Interestingly, NMR embryonic fibroblasts and the derived iPSCs had propensity for a tetraploid karyotype and were resistant to forming teratomas, but within mouse blastocysts they contributed to both interspecific placenta and fetus. Gene expression patterns of NMR iPSCs were more similar to those of human than mouse iPSCs. Overall, we uncovered unique features of NMR iPSCs and report a mouse-NMR chimeric model. The iPSCs and associated cell culture systems can be used for a variety of biological and biomedical applications.

  19. Interspecific competition and allelopathic interaction between Karenia mikimotoi and Dunaliella salina in laboratory culture

    Science.gov (United States)

    He, Dong; Liu, Jiao; Hao, Qiang; Ran, Lihua; Zhou, Bin; Tang, Xuexi

    2016-03-01

    Algal allelopathy is a manifold ecological/physiological phenomenon that is focused on chemical interactions and autotoxicity. We investigated the allelopathic interactions between Karenia mikimotoi and Dunaliella salina in laboratory cultures based on diff erent temperature (15°C, 20°C, and 25°C) and lighting (40, 80, and 160 μmol/(m2·s)) conditions. The growth of D. salina in bi-algae culture (1:1 size/density) was significantly restrained. The results of cell-free filtrate culture indicate that direct cell-tocell contact was not necessary in interspecific competition. Further experimental results demonstrated that allelochemicals released from K. mikimotoi were markedly influenced by both temperature ( P =0.013) and irradiance ( P =0.003), resulting in diff erent growth characteristics of D. salina in filtrate mediums. Compared with the plateau period, K. mikimotoi exudates in the exponential phase had a stronger short-term inhibition effect on D. salina in normal conditions. A clear concentration-dependent relationship was observed in the effect of allelochemicals released from K. mikimotoi with low-promoting and high-repressing effects on D. Salina in a short time-scale. In addition, allelopathic substances remain stable and effective under high temperature and pressure stress. Many flocculent sediments adhering with D. salina cells were observed in all filtrate mediums, while the quantity and color depended on the original culture conditions.

  20. Interspecific competition between Solenopsis invicta and two native ant species, Pheidole fervens and Monomorium chinense.

    Science.gov (United States)

    Chen, Yin-Cheng; Kafle, Lekhnath; Shih, Cheng-Jen

    2011-04-01

    This study was designed to understand the effects of the interspecific competition between red imported fire ant, Solenopsis invicta Buren and two native ant species, Pheidole fervens Smith and Monomorium chinense Santschi, by conducting colony interference and individual confrontation tests under laboratory conditions. The colony interference test showed that both native ant species, owing to their numerical advantage, killed the Solenopsis invicta virus-1 (SINV-1)-infected or healthy queens of S. invicta. Significantly less time was required for M. chinense to kill all SINV-1-infected S. invicta compared with the time required to kill the healthy S. invicta. Compared with healthy S. invicta, SINV-1-infected S. invicta spent a longer time eliminating the P. fervens colonies. In confrontation tests, M. chinense killed a significantly higher number of infected S. invicta minors than they did healthy minors, but the number of S. invicta majors (either infected or healthy) killed was substantially less. This study found that the viral infection weakened the competitive ability of S. invicta and made them prone to be eliminated by M. chinense but not by P. fervens.

  1. Positive selection and propeptide repeats promote rapid interspecific divergence of a gastropod sperm protein.

    Science.gov (United States)

    Hellberg, M E; Moy, G W; Vacquier, V D

    2000-03-01

    Male-specific proteins have increasingly been reported as targets of positive selection and are of special interest because of the role they may play in the evolution of reproductive isolation. We report the rapid interspecific divergence of cDNA encoding a major acrosomal protein of unknown function (TMAP) of sperm from five species of teguline gastropods. A mitochondrial DNA clock (calibrated by congeneric species divided by the Isthmus of Panama) estimates that these five species diverged 2-10 MYA. Inferred amino acid sequences reveal a propeptide that has diverged rapidly between species. The mature protein has diverged faster still due to high nonsynonymous substitution rates (> 25 nonsynonymous substitutions per site per 10(9) years). cDNA encoding the mature protein (89-100 residues) shows evidence of positive selection (Dn/Ds > 1) for 4 of 10 pairwise species comparisons. cDNA and predicted secondary-structure comparisons suggest that TMAP is neither orthologous nor paralogous to abalone lysin, and thus marks a second, phylogenetically independent, protein subject to strong positive selection in free-spawning marine gastropods. In addition, an internal repeat in one species (Tegula aureotincta) produces a duplicated cleavage site which results in two alternatively processed mature proteins differing by nine amino acid residues. Such alternative processing may provide a mechanism for introducing novel amino acid sequence variation at the amino-termini of proteins. Highly divergent TMAP N-termini from two other tegulines (Tegula regina and Norrisia norrisii) may have originated by such a mechanism.

  2. Effects of local adaptation and interspecific competition on species' responses to climate change.

    Science.gov (United States)

    Bocedi, Greta; Atkins, Katherine E; Liao, Jishan; Henry, Roslyn C; Travis, Justin M J; Hellmann, Jessica J

    2013-09-01

    Local adaptation and species interactions have been shown to affect geographic ranges; therefore, we need models of climate impact that include both factors. To identify possible dynamics of species when including these factors, we ran simulations of two competing species using an individual-based, coupled map-lattice model using a linear climatic gradient that varies across latitude and is warmed over time. Reproductive success is governed by an individual's adaptation to local climate as well as its location relative to global constraints. In exploratory experiments varying the strength of adaptation and competition, competition reduces genetic diversity and slows range change, although the two species can coexist in the absence of climate change and shift in the absence of competitors. We also found that one species can drive the other to extinction, sometimes long after climate change ends. Weak selection on local adaptation and poor dispersal ability also caused surfing of cooler-adapted phenotypes from the expanding margin backwards, causing loss of warmer-adapted phenotypes. Finally, geographic ranges can become disjointed, losing centrally-adapted genotypes. These initial results suggest that the interplay between local adaptation and interspecific competition can significantly influence species' responses to climate change, in a way that demands future research. © 2013 New York Academy of Sciences.

  3. Concentration of trace elements in feathers of three Antarctic penguins: Geographical and interspecific differences

    International Nuclear Information System (INIS)

    Jerez, Silvia; Motas, Miguel; Palacios, Maria Jose; Valera, Francisco; Cuervo, Jose Javier; Barbosa, Andres

    2011-01-01

    Antarctica is often considered as one of the last pristine regions, but it could be affected by pollution at global and local scale. Concentrations of Al, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Cd and Pb were determinated by ICP-MS in feathers (n = 207 individuals) of gentoo, chinstrap and Adelie penguin collected in 8 locations throughout the Antarctic Peninsula (2006-2007). The highest levels of several elements were found in samples from King George Island (8.08, 20.29 and 1.76 μg g -1 dw for Cr, Cu and Pb, respectively) and Deception Island (203.13, 3.26 and 164.26 μg g -1 dw for Al, Mn and Fe, respectively), where probably human activities and large-scale transport of pollutants contribute to increase metal levels. Concentrations of Cr, Mn, Cu, Se or Pb, which are similar to others found in different regions of the world, show that some areas in Antarctica are not utterly pristine. - Highlights: → We study levels of trace elements in feathers of Antarctic penguins. → Eight different rookeries throughout the Antarctic Peninsula were sampled. → Interspecific (gentoo, chinstrap, Adelie) and geographical differences were tested. → Relatively high metal levels were found in areas with major human presence. → Penguin feather can be useful for metals monitoring in the Antarctic environment. - Trace element levels in feathers of three penguin species from the Antarctic Peninsula indicate the presence of pollution in certain locations.

  4. Informational mismatches: a neglected threat of climate change to interspecific interactions

    Directory of Open Access Journals (Sweden)

    Deseada eParejo

    2016-04-01

    Full Text Available Interspecific interactions are deeply affected by the current scenario of climate change. This is because interactions are sensitive to many traits of interacting species as phenology, distribution, behaviour and relative abundances which may be differently influenced by climate change in each species. In this scenario, positive interactions, which require temporal coordination of events of life history of interacting species, could be particularly altered due to differential effects of climate change on phenology, apart from by the effects on abundance and distribution. Hitherto, studies focusing on the effects of climate change on positive biotic interactions are scarce and mainly focused on plant-pollinator interactions. Here I propose that, by inducing informational mismatches, climate change may lead to individuals from competing species relying on heterospecific social information to making mis- or un-informed decisions. The idea is that competing species are valuable sources of social information to each other provided overlap of their activities occurs. However, whenever coordination of events fails, competing species will co-occur at the wrong moment, co-occur only in small numbers or even not co-occur at all and thus they will not be able to access useful or any social information from heterospecifics. In that scenario, interacting species would be mis- or un- informed, and, consequently, decision taking will be impaired, leading to disequilibrium in the community. Throughout the manuscript, I will develop the idea of mismatches of information and illustrate it with some case studies.

  5. Learning and owner-stranger effects on interspecific communication in domestic dogs (Canis familiaris).

    Science.gov (United States)

    Elgier, Angel M; Jakovcevic, Adriana; Mustaca, Alba E; Bentosela, Mariana

    2009-05-01

    Domestic dogs are very successful at following human cues like gazing or pointing to find hidden food in an object choice task. They solve this kind of situation at their first attempts and from early stages of their development and perform better than wolves. Most of the authors proposed that these abilities are a domestication product, and independent from learning processes. There are few systematic studies on the effects of learning on dogs' communicative skills. We aim to evaluate the effect of extinction and reversal learning procedures on the use of the pointing gesture in an object choice task. The results showed that dogs stopped following the pointing cue in the extinction and that they learned to choose the not pointed container in the reversal learning. Results suggest that instrumental learning plays an important role in interspecific communication mechanisms between humans and dogs. In both experiments for half of the subjects the pointer was the owner and for the rest was a stranger. A differential effect was found: extinction was slower but reversal learning was faster when the owner gave the cue. This data indicates that the relationship of the dog with the person who emits the cue influences performance.

  6. Interspecific competition alters natural selection on shade avoidance phenotypes in Impatiens capensis.

    Science.gov (United States)

    McGoey, Brechann V; Stinchcombe, John R

    2009-08-01

    Shade avoidance syndrome is a known adaptive response for Impatiens capensis growing in dense intraspecific competition. However, I. capensis also grow with dominant interspecific competitors in marshes. Here, we compare the I. capensis shade-avoidance phenotypes produced in the absence and presence of heterospecific competitors, as well as selection on those traits. Two treatments were established in a marsh; in one treatment all heterospecifics were removed, while in the other, all competitors remained. We compared morphological traits, light parameters, seed output and, using phenotypic selection analysis, examined directional and nonlinear selection operating in the different competitive treatments. Average phenotypes, light parameters and seed production all varied depending on competitive treatment. Phenotypic selection analyses revealed different directional, disruptive, stabilizing and correlational selection. The disparities seen in both phenotypes and selection between the treatments related to the important differences in elongation timing depending on the presence of heterospecifics, although environmental covariances between traits and fitness could also contribute. Phenotypes produced by I. capensis depend on their competitive environment, and differing selection on shade-avoidance traits between competitive environments could indirectly select for increased plasticity given gene flow between populations in different competitive contexts.

  7. SOCIO-PSYCHOLOGICAL EFFECTS OF INTERSPECIFIC INTERACTIONS IN A GROUP “HUMAN - PET”

    Directory of Open Access Journals (Sweden)

    A V Gagarin

    2016-12-01

    Full Text Available The article reveals the features of interspecific interaction “Human - Pet” in aspects of psychology and behaviorism. This direction is shown to be promising in the theoretical and applied aspects. This is significant for the study of individual social activity and human life, as well as social groups. The article identifies the promising areas of the research of such interaction: in the development of family and child-parent relations; in the asocial individual development under the influence of various factors (social and personal; in various directions of media development (social advertising on television and in print, in fiction and film; in socially-significant communicating in social networks (communication through video sharing, etc.. It is shown that this perspective is important for research in education and upbringing. We have come to the conclusion that the problems are of social significance because the direct and/or indirect human contact with natural objects contributes to the development of different spheres of his/her personality (cognitive, communicative, aesthetic, ethical, emotional, volitional.

  8. [Effects of precipitation and interspecific competition on Quercus mongolica and pinus koraiensis seedlings growth].

    Science.gov (United States)

    Wu, Jing-Lian; Wang, Miao; Lin, Fei; Hao, Zhan-Qing; Ji, Lan-Zhu; Liu, Ya-Qin

    2009-02-01

    Aiming at the variation of precipitation pattern caused by global warming, a field simulation experiment was conducted to study the effects of 30% increase (+W) and decrease (-W) of precipitation on the morphology, growth, and biomass partitioning of mono- and mixed cultured seedlings of Quercus mongolica and Pinus koraiensis, the two dominant tree species in temperate broad-leaved Korean pine mixed forest in Changbai Mountains. Comparing with monoculture, mixed culture increased the canopy width and main root length of Q. mongolica seedlings, but decreased the basal diameter, plant height, leaf number, and dry masses of root, stem, leaf and whole plant of P. koraiensis seedlings significantly. Treatment (-W) increased the stem/mass ratio while decreased the main root length of Q. mongolica seedlings, and decreased the main root length, leaf number, dry masses of leaf and whole plant, and leaf/mass ratio, while increased the stem/mass ratio of P. koraiensis seedlings significantly, compared with treatment CK. Treatment (+W) had no significant effect on these indices of the two species. At early growth stage, interspecific competition and precipitation pattern had significant effects on the morphology and growth of the seedlings, and the responses were much stronger for P. koraiensis than for Q. mongolica.

  9. Intra- and interspecific competition between western flower thrips and sweetpotato whitefly.

    Science.gov (United States)

    Wu, Qing-Jun; Hou, Wen-Jie; Li, Fei; Xu, Bao-Yun; Xie, Wen; Wang, Shao-Li; Zhang, You-Jun

    2014-01-01

    The western flower thrips, Frankliniella occidentalis (Pergande), and the sweetpotato whitefly, Bemisia tabaci (Gennadius), are both invasive insect pests and are present in most of the same agricultural crops without a clear dominance of either species. Here, intra- and interspecific competition in B. tabaci and F. occidentalis was determined under controlled experiments. The results showed that intraspecific competition was distinct in F. occidentalis and that the co-occurrence of B. tabaci had a strong effect on F. occidentalis, resulting in a decrease in oviposition. Significant intraspecific competition was found in B. tabaci, and the coexistence of F. occidentalis had limited effect on the oviposition of B. tabaci. In a selective host plant preference experiment, both F. occidentalis and B. tabaci preferred eggplants most, followed by cucumbers and tomatoes. On cucumber plants, B. tabaci was predominant, whereas on eggplant and tomato plants, F. occidentalis and B. tabaci exhibited comparative competitive abilities during the initial stage. However, over time, higher numbers of B. tabaci than that of F. occidentalis were found on the two host plants. Our in vitro and potted plant experiments indicate that B. tabaci is competitively superior to F. occidentalis, which might help to explain their differential distribution patterns in China. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

  10. Interspecific competition in plants: how well do current methods answer fundamental questions?

    Science.gov (United States)

    Connolly, J; Wayne, P; Bazzaz, F A

    2001-02-01

    Accurately quantifying and interpreting the processes and outcomes of competition among plants is essential for evaluating theories of plant community organization and evolution. We argue that many current experimental approaches to quantifying competitive interactions introduce size bias, which may significantly impact the quantitative and qualitative conclusions drawn from studies. Size bias generally arises when estimates of competitive ability are erroneously influenced by the initial size of competing individuals. We employ a series of quantitative thought experiments to demonstrate the potential for size bias in analysis of four traditional experimental designs (pairwise, replacement series, additive series, and response surfaces) either when only final measurements are available or when both initial and final measurements are collected. We distinguish three questions relevant to describing competitive interactions: Which species dominates? Which species gains? and How do species affect each other? The choice of experimental design and measurements greatly influences the scope of inference permitted. Conditions under which the latter two questions can give biased information are tabulated. We outline a new approach to characterizing competition that avoids size bias and that improves the concordance between research question and experimental design. The implications of the choice of size metrics used to quantify both the initial state and the responses of elements in interspecific mixtures are discussed. The relevance of size bias in competition studies with organisms other than plants is also discussed.

  11. Spatial heterogeneity of plant-soil feedback affects root interactions and interspecific competition.

    Science.gov (United States)

    Hendriks, Marloes; Ravenek, Janneke M; Smit-Tiekstra, Annemiek E; van der Paauw, Jan Willem; de Caluwe, Hannie; van der Putten, Wim H; de Kroon, Hans; Mommer, Liesje

    2015-08-01

    Plant-soil feedback is receiving increasing interest as a factor influencing plant competition and species coexistence in grasslands. However, we do not know how spatial distribution of plant-soil feedback affects plant below-ground interactions. We investigated the way in which spatial heterogeneity of soil biota affects competitive interactions in grassland plant species. We performed a pairwise competition experiment combined with heterogeneous distribution of soil biota using four grassland plant species and their soil biota. Patches were applied as quadrants of 'own' and 'foreign' soils from all plant species in all pairwise combinations. To evaluate interspecific root responses, species-specific root biomass was quantified using real-time PCR. All plant species suffered negative soil feedback, but strength was species-specific, reflected by a decrease in root growth in own compared with foreign soil. Reduction in root growth in own patches by the superior plant competitor provided opportunities for inferior competitors to increase root biomass in these patches. These patterns did not cascade into above-ground effects during our experiment. We show that root distributions can be determined by spatial heterogeneity of soil biota, affecting plant below-ground competitive interactions. Thus, spatial heterogeneity of soil biota may contribute to plant species coexistence in species-rich grasslands. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  12. INTERSPECIFIC COMPETITION BETWEEN NATIVE AND EXOTIC FRUIT FLY PARASITOIDSIN MIXED ORCHARDS IN MACEIO, ALAGOAS, BRAZIL

    Directory of Open Access Journals (Sweden)

    JAKELINE MARIA DOS SANTOS

    2016-01-01

    Full Text Available The objective of this work was to assess the effects of the release and establishment of the exotic parasitoid Diachasmimorpha longicaudata (Ashmead, 1905 (Hymenoptera: Braconidae and its interspecific competitive relationship with native fruit fly parasitoids in organic and conventional orchards in Maceio, State of Alagoas, Brazil. The exotic parasitoids were reared in the Radio - Entomology Laboratory of the Center for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, São Paulo, and released (112,350 individuals between five and eight days old in orchards from June 8 to July12, 2013.Fruit samples were collected randomly every week during one year to assess the D. longicaudata recaptured from plants and fallen fruits on the ground, which were taken to the Entomology Laboratory of the CECA - UFAL, classified and individually placed in plastic containers, containing a layer of 1 cm of sand for pupation of the host larvae. The pupae, obtained after 10 days, were placed in Petri dishes with a layer of sand until the emergence of adults, which were then kept in plastic microtubes, containing ethanol 70%. The release of exotic parasitoids did not displace native species. The same species were found before and after the release in both cultures: Doryctobracon areolatus , Asobara anastrephae , Utetes anastrephae and Opius bellus (Braconidae, Aganaspis pelleranoi (Figitidae and individuals of the Pteromalidae family. One year after the last release, 44 individuals of the exotic parasitoid were found, showing its establishment in the studied areas.

  13. Behavioral and life-history evidence for interspecific competition in the larvae of two heliconian butterflies

    Science.gov (United States)

    Millan, Carolina; Borges, Simone Silva; Rodrigues, Daniela; Moreira, Gilson Rudinei Pires

    2013-10-01

    Interspecific competition in herbivorous insects remains a controversial issue. To date, many studied systems have not met assumptions of the traditional competition theory, and a new paradigm has been emerging. We examined the behavioral and life-history consequences of common host plant use of Heliconius erato and Dryas iulia (Nymphalidae) in relation to Passiflora suberosa (Passifloraceae). Larvae of the former use the apical portion of this host; the latter is presumably able to explore all plant parts. We assessed host use pattern in relation to leaf age, when reared either alone ( D. iulia) or together ( D. iulia and H. erato). Larval feeding choice tests with respect to leaf age were performed, and performance was recorded. Observations were made to assess antagonistic behavior of H. erato and D. iulia towards each other, if any. Similarly to H. erato, D. iulia fed on the young leaves significantly more than the mature ones; larvae were not induced to prefer mature leaves. First instars of H. erato used only the apical parts of P. suberosa and displayed aggressive behavior towards D. iulia, which moved to the lower shoot portions. Larval mortality and development time of both species significantly increased when reared together; such performance costs were more pronounced in D. iulia than H. erato. Our study gathers evidences that use of P. suberosa by these heliconian butterflies represent a case of competitive exclusion resulting in niche differentiation, where costs are higher for D. iulia than H. erato.

  14. TAI vacuolar invertase orthologs: the interspecific variability in tomato plants (Solanum section Lycopersicon).

    Science.gov (United States)

    Slugina, M A; Shchennikova, A V; Kochieva, E Z

    2017-10-01

    Understanding the genetic mechanisms underlying carbohydrate metabolism can promote the development of biotechnological advances in fruit plants. The flesh tomato fruit represents an ideal system for examining the role of sucrose cleavage enzymes in fruit development, and wild tomato species differing in storage sugars serve as an excellent research material for this purpose. Plant vacuolar invertase is a key enzyme of sucrose metabolism in the sink organs. In the present study, we identified complete gene sequences encoding the TAI vacuolar invertase in 11 wild and one cultivated tomato accessions of the Solanum section Lycopersicon. The average level of interspecific polymorphism in TAI genes was 8.58%; however, in the green-fruited tomatoes, the TAI genes contained 100 times more SNPs than those in the red-fruited accessions. The TAI proteins demonstrated 8% variability, whereas the red-fruited species had none. A TAI-based phylogenetic tree revealed two main clusters containing self-compatible and self-incompatible species, which concurs with the previous crossability-based division and demonstrates that the TAI genes reflect the evolutionary relationships between the red- and green-fruited tomatoes. Furthermore, we detected differential expression patterns of the TAI genes in the fruits of wild and cultivated tomatoes, which corresponded to sugar composition. The polymorphism analysis of the TAI acid invertases of Solanum section Lycopersicon species will contribute to the understanding of the genetic potential of TAI genes to impact tomato breeding through genetic engineering of the carbohydrate composition in the fruit.

  15. Effect of breakup on near barrier fusion

    International Nuclear Information System (INIS)

    Dasgupta, M.; Berriman, A.C.; Butt, R.D.; Hinde, D.J.; Morton, C.R.; Newton, J.O.

    2000-01-01

    Full text: Unstable neutron-rich nuclei having very weakly bound neutrons exhibit characteristic features such as a neutron halo extending to large radii, and a low energy threshold for breakup. These features may dramatically affect fusion and other reaction processes. It is well accepted that the extended nuclear matter distribution will lead to an enhancement in fusion cross-sections over those for tightly bound nuclei. The effect of couplings to channels which act as doorways to breakup is, however, controversial, with model predictions differing in the relative magnitudes of enhancement and suppression. To investigate the effect on fusion of couplings specific to unstable neutron-rich nuclei, it is necessary to understand (and then predict) the cross-sections expected for their stable counterparts. This requires knowledge of the energy of the average fusion barrier, and information on the couplings. Experimentally all this information can be obtained from precisely measured fusion cross-sections. Such precision measurements of complete fusion cross-sections for 9 Be + 208 Pb and 6 Li, 7 Li + 209 Bi systems have been done at the Australian National University. The distribution of fusion barriers extracted from these data were used to reliably predict the expected fusion cross-sections. Comparison of the theoretical expectations with the experimentally measured cross-sections show conclusively that complete fusion, at above barrier energies, for all three systems is suppressed (by about 30%) compared with the fusion of more tightly bound nuclei. These measurements, in conjunction with incomplete fusion cross-sections, which were also measured, should encourage a complete theoretical description of fusion and breakup

  16. Vehicle barrier systems

    International Nuclear Information System (INIS)

    Sena, P.A.

    1986-01-01

    The ground vehicle is one of the most effective tools available to an adversary force. Vehicles can be used to penetrate many types of perimeter barriers, transport equipment and personnel rapidly over long distances, and deliver large amounts of explosives directly to facilities in suicide missions. The function of a vehicle barrier system is to detain or disable a defined threat vehicle at a selected distance from a protected facility. Numerous facilities are installing, or planning to install, vehicle barrier systems and many of these facilities are requesting guidance to do so adequately. Therefore, vehicle barriers are being evaluated to determine their stopping capabilities so that systems can be designed that are both balanced and capable of providing a desired degree of protection. Equally important, many of the considerations that should be taken into account when establishing a vehicle barrier system have been identified. These considerations which pertain to site preparation, barrier selection, system integration and operation, and vehicle/barrier interaction, are discussed in this paper

  17. Converse Barrier Certificate Theorem

    DEFF Research Database (Denmark)

    Wisniewski, Rafael; Sloth, Christoffer

    2013-01-01

    This paper presents a converse barrier certificate theorem for a generic dynamical system.We show that a barrier certificate exists for any safe dynamical system defined on a compact manifold. Other authors have developed a related result, by assuming that the dynamical system has no singular...... points in the considered subset of the state space. In this paper, we redefine the standard notion of safety to comply with generic dynamical systems with multiple singularities. Afterwards, we prove the converse barrier certificate theorem and illustrate the differences between ours and previous work...

  18. Disentangling the effects of species diversity, and intraspecific and interspecific tree size variation on aboveground biomass in dry zone homegarden agroforestry systems.

    Science.gov (United States)

    Ali, Arshad; Mattsson, Eskil

    2017-11-15

    The biodiversity - aboveground biomass relationship has been intensively studied in recent decades. However, no consensus has been arrived to consider the interplay of species diversity, and intraspecific and interspecific tree size variation in driving aboveground biomass, after accounting for the effects of plot size heterogeneity, soil fertility and stand quality in natural forest including agroforests. We tested the full, partial and no mediations effects of species diversity, and intraspecific and interspecific tree size variation on aboveground biomass by employing structural equation models (SEMs) using data from 45 homegarden agroforestry systems in Sri Lanka. The full mediation effect of either species diversity or intraspecific and interspecific tree size variation was rejected, while the partial and no mediation effects were accepted. In the no mediation SEM, homegarden size had the strongest negative direct effect (β=-0.49) on aboveground biomass (R 2 =0.65), followed by strong positive direct effect of intraspecific tree size variation (β=0.32), species diversity (β=0.29) and interspecific tree size variation (β=0.28). Soil fertility had a negative direct effect on interspecific tree size variation (β=-0.31). Stand quality had a significant positive total effect on aboveground biomass (β=0.28), but homegarden size had a significant negative total effect (β=-0.62), while soil fertility had a non-significant total effect on aboveground biomass. Similar to the no mediation SEM, the partial mediation SEMs had explained almost similar variation in aboveground biomass because species diversity, and intraspecific and interspecific tree size variation had non-significant indirect effects on aboveground biomass via each other. Our results strongly suggest that a multilayered tree canopy structure, due to high intraspecific and interspecific tree size variation, increases light capture and efficient utilization of resources among component species, and

  19. Information barriers and authentication

    International Nuclear Information System (INIS)

    MacArthur, D.W.; Wolford, J.K.

    2001-01-01

    Acceptance of nuclear materials into a monitoring regime is complicated if the materials are in classified shapes or have classified composition. An attribute measurement system with an information barrier can be emplo,yed to generate an unclassified display from classified measurements. This information barrier must meet two criteria: (1) classified information cannot be released to the monitoring party, and (2) the monitoring party must be convinced that the unclassified output accurately represents the classified input. Criterion 1 is critical to the host country to protect the classified information. Criterion 2 is critical to the monitoring party and is often termed the 'authentication problem.' Thus, the necessity for authentication of a measurement system with an information barrier stems directly from the description of a useful information barrier. Authentication issues must be continually addressed during the entire development lifecycle of the measurement system as opposed to being applied only after the system is built.

  20. Barrier Infrared Detector (BIRD)

    Data.gov (United States)

    National Aeronautics and Space Administration — A recent breakthrough in MWIR detector design, has resulted in a high operating temperature (HOT) barrier infrared detector (BIRD) that is capable of spectral...

  1. Protective barrier development: Overview

    International Nuclear Information System (INIS)

    Wing, N.R.; Gee, G.W.

    1990-01-01

    Protective barrier and warning marker systems are being developed to isolate wastes disposed of near the earth's surface at the Hanford Site. The barrier is designed to function in an arid to semiarid climate, to limit infiltration and percolation of water through the waste zone to near-zero, to be maintenance free, and to last up to 10,000 yr. Natural materials (e.g., fine soil, sand, gravel, riprap, clay, asphalt) have been selected to optimize barrier performance and longevity and to create an integrated structure with redundant features. These materials isolate wastes by limiting water drainage; reducing the likelihood of plant, animal, and human intrusion; controlling emission of noxious gases; and minimizing erosion. Westinghouse Hanford Company and Pacific Northwest Laboratory efforts to assess the performance of various barrier and marker designs will be discussed

  2. Engineered barriers: current status

    International Nuclear Information System (INIS)

    Atkinson, A.; Marsh, G.P.

    1988-01-01

    This report summarises the current state of research relevant to assessing the performance of engineered barriers made of steel and concrete in radioactive waste repositories. The objective of these barriers is to contain the radionuclides within them by providing both physical and chemical impediment to their release. The physical barriers are of most value for highly soluble isotopes with relatively short half-lives (eg 137 Cs), since they can provide containment until a large fraction of the activity has decayed. In addition they can facilitate retrievability for some period after disposal. The chemical barriers operate by beneficial conditioning of the near field groundwater and providing sites for sorption of radionuclides. Both of these reduce the aqueous concentration of radionuclides in the near field. (author)

  3. Relationships between Nutrient Heterogeneity, Root Growth, and Hormones: Evidence for Interspecific Variation.

    Science.gov (United States)

    Dong, Jia; Jones, Robert H; Mou, Pu

    2018-02-28

    (1) Background: Plant roots respond to nutrients through root architecture that is regulated by hormones. Strong inter-specific variation in root architecture has been well documented, but physiological mechanisms that may control the variation have not. (2) Methods: We examined correlations between root architecture and hormones to seek clues on mechanisms behind root foraging behavior. In the green house at Beijing Normal University, hydroponic culture experiments were used to examine the root responses of four species- Callistephus chinensis , Solidago canadensis , Ailanthus altissima , Oryza sativa- to two nitrogen types (NO₃ - or NH₄⁺), three nitrogen concentrations (low, medium, and high concentrations of 0.2, 1, and 18 mM, respectively) and two ways of nitrogen application (stable vs. variable). The plants were harvested after 36 days to measure root mass, 1st order root length, seminal root length for O. sativa , density of the 1st order laterals, seminal root number for O. sativa , the inter-node length of the 1st order laterals, and root hormone contents of indole-3-acetic acid, abscisic acid, and cytokinins (zeatin + zeatinriboside). (3) Results: Species differed significantly in their root architecture responses to nitrogen treatments. They also differed significantly in hormone responses to the nitrogen treatments. Additionally, the correlations between root architecture and hormone responses were quite variable across the species. Each hormone had highly species-specific relationships with root responses. (4) Conclusions: Our finding implies that a particular root foraging behavior is probably not controlled by the same biochemical pathway in all species.

  4. Relationships between Nutrient Heterogeneity, Root Growth, and Hormones: Evidence for Interspecific Variation

    Directory of Open Access Journals (Sweden)

    Jia Dong

    2018-02-01

    Full Text Available (1 Background: Plant roots respond to nutrients through root architecture that is regulated by hormones. Strong inter-specific variation in root architecture has been well documented, but physiological mechanisms that may control the variation have not. (2 Methods: We examined correlations between root architecture and hormones to seek clues on mechanisms behind root foraging behavior. In the green house at Beijing Normal University, hydroponic culture experiments were used to examine the root responses of four species—Callistephus chinensis, Solidago canadensis, Ailanthus altissima, Oryza sativa—to two nitrogen types (NO3− or NH4+, three nitrogen concentrations (low, medium, and high concentrations of 0.2, 1, and 18 mM, respectively and two ways of nitrogen application (stable vs. variable. The plants were harvested after 36 days to measure root mass, 1st order root length, seminal root length for O. sativa, density of the 1st order laterals, seminal root number for O. sativa, the inter-node length of the 1st order laterals, and root hormone contents of indole-3-acetic acid, abscisic acid, and cytokinins (zeatin + zeatinriboside. (3 Results: Species differed significantly in their root architecture responses to nitrogen treatments. They also differed significantly in hormone responses to the nitrogen treatments. Additionally, the correlations between root architecture and hormone responses were quite variable across the species. Each hormone had highly species-specific relationships with root responses. (4 Conclusions: Our finding implies that a particular root foraging behavior is probably not controlled by the same biochemical pathway in all species.

  5. Intra- and interspecific differences in diet quality and composition in a large herbivore community.

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    Claire Redjadj

    Full Text Available Species diversity in large herbivore communities is often explained by niche segregation allowed by differences in body mass and digestive morphophysiological features. Based on large number of gut samples in fall and winter, we analysed the temporal dynamics of diet composition, quality and interspecific overlap of 4 coexisting mountain herbivores. We tested whether the relative consumption of grass and browse differed among species of different rumen types (moose-type and intermediate-type, whether diet was of lower quality for the largest species, whether we could identify plant species which determined diet quality, and whether these plants, which could be "key-food-resources" were similar for all herbivores. Our analyses revealed that (1 body mass and rumen types were overall poor predictors of diet composition and quality, although the roe deer, a species with a moose-type rumen was confirmed as an "obligatory non grazer", while red deer, the largest species, had the most lignified diet; (2 diet overlap among herbivores was well predicted by rumen type (high among species of intermediate types only, when measured over broad plant groups, (3 the relationship between diet composition and quality differed among herbivore species, and the actual plant species used during winter which determined the diet quality, was herbivore species-specific. Even if diets overlapped to a great extent, the species-specific relationships between diet composition and quality suggest that herbivores may select different plant species within similar plant group types, or different plant parts and that this, along with other behavioural mechanisms of ecological niche segregation, may contribute to the coexistence of large herbivores of relatively similar body mass, as observed in mountain ecosystems.

  6. Receding Water Line and Interspecific Competition Determines Plant Community Composition and Diversity in Wetlands in Beijing

    Science.gov (United States)

    Wang, Zhengjun; Gong, Huili; Zhang, Jing

    2015-01-01

    Climate and human-induced wetland degradation has accelerated in recent years, not only resulting in reduced ecosystem services but also greatly affecting the composition and diversity of wetland plant communities. To date, the knowledge of the differences in community parameters and their successional trends in degraded wetlands remains scarce. Here based on remote sensing images, geographic information system technology, and statistical methods, we produced a successional gradient map of the Yeyahu Wetland Nature Reserve in Beijing, which has experienced a steady decline in water level in recent decades. In addition, we analyzed community composition and diversity along with each identified gradient. The results showed that community diversity decreases while dominance increases with the progress of succession, with the highest diversity occurring during the early stage of succession. Moreover, the community demonstrates greater similarity among subareas during later successional stages, and the similarity coefficients calculated from the important value (IV) of each species are more accurate. Correlation analysis showed that the impact of soil factors on diversity was not significant at a subarea scale, although these nutrients showed an increasing trend with the community succession. Furthermore, the IVs of the dominant species had a particularly significant impact on diversity, showing a significantly negative correlation with diversity indices and a significantly positive correlation with dominance indices. Further analysis showed that the retreat of water level resulted from sustained drought and local human activities was a major extrinsic driving force resulting in observed differences in the community successional stages, which resulted in differences in community composition and diversity. On the other hand, interspecific competition was the main intrinsic mechanism, which significantly influenced the IVs of the dominant species and community diversity

  7. Interspecific variation in life history relates to antipredator decisions by marine mesopredators on temperate reefs.

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    Alejandro Frid

    Full Text Available As upper-level predatory fishes become overfished, mesopredators rise to become the new 'top' predators of over-exploited marine communities. To gain insight into ensuing mechanisms that might alter indirect species interactions, we examined how behavioural responses to an upper-level predatory fish might differ between mesopredator species with different life histories. In rocky reefs of the northeast Pacific Ocean, adult lingcod (Ophiodon elongatus are upper-level predators that use a sit-and-wait hunting mode. Reef mesopredators that are prey to adult lingcod include kelp greenling (Hexagrammos decagrammus, younger lingcod, copper rockfish (Sebastes caurinus and quillback rockfish (S. maliger. Across these mesopredators species, longevity and age at maturity increases and, consequently, the annual proportion of lifetime reproductive output decreases in the order just listed. Therefore, we hypothesized that the level of risk taken to acquire resources would vary interspecifically in that same order. During field experiments we manipulated predation risk with a model adult lingcod and used fixed video cameras to quantify interactions between mesopredators and tethered prey (Pandalus shrimps. We predicted that the probabilities of inspecting and attacking tethered prey would rank from highest to lowest and the timing of these behaviours would rank from earliest to latest as follows: kelp greenling, lingcod, copper rockfish, and quillback rockfish. We also predicted that responses to the model lingcod, such as avoidance of interactions with tethered prey, would rank from weakest to strongest in the same order. Results were consistent with our predictions suggesting that, despite occupying similar trophic levels, longer-lived mesopredators with late maturity have stronger antipredator responses and therefore experience lower foraging rates in the presence of predators than mesopredators with faster life histories. The corollary is that the fishery

  8. Local climate determines intra- and interspecific variation in sexual size dimorphism in mountain grasshopper communities.

    Science.gov (United States)

    Laiolo, P; Illera, J C; Obeso, J R

    2013-10-01

    The climate is often evoked to explain broad-scale clines of body size, yet its involvement in the processes that generate size inequality in the two sexes (sexual size dimorphism) remains elusive. Here, we analyse climatic clines of sexual size dimorphism along a wide elevation gradient (i) among grasshopper species in a phylogenetically controlled scenario and (ii) within species differing in distribution and cold tolerance, to highlight patterns generated at different time scales, mainly evolutionary (among species or higher taxa) and ontogenetic or microevolutionary (within species). At the interspecific level, grasshoppers were slightly smaller and less dimorphic at high elevations. These clines were associated with gradients of precipitation and sun exposure, which are likely indicators of other factors that directly exert selective pressures, such as resource availability and conditions for effective thermoregulation. Within species, we found a positive effect of temperature and a negative effect of elevation on body size, especially on condition-dependent measures of body size (total body length rather than hind femur length) and in species inhabiting the highest elevations. In spite of a certain degree of species-specific variation, females tended to adjust their body size more often than males, suggesting that body size in females can evolve faster among species and can be more plastic or dependent on nutritional conditions within species living in adverse climates. Natural selection on female body size may therefore prevail over sexual selection on male body size in alpine environments, and abiotic factors may trigger consistent phenotypic patterns across taxonomic scales. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

  9. Influence of Interspecific Competition and Landscape Structure on Spatial Homogenization of Avian Assemblages

    Science.gov (United States)

    Robertson, Oliver J.; McAlpine, Clive; House, Alan; Maron, Martine

    2013-01-01

    Human-induced biotic homogenization resulting from landscape change and increased competition from widespread generalists or ‘winners’, is widely recognized as a global threat to biodiversity. However, it remains unclear what aspects of landscape structure influence homogenization. This paper tests the importance of interspecific competition and landscape structure, for the spatial homogeneity of avian assemblages within a fragmented agricultural landscape of eastern Australia. We used field observations of the density of 128 diurnal bird species to calculate taxonomic and functional similarity among assemblages. We then examined whether taxonomic and functional similarity varied with patch type, the extent of woodland habitat, land-use intensity, habitat subdivision, and the presence of Manorina colonies (a competitive genus of honeyeaters). We found the presence of a Manorina colony was the most significant factor positively influencing both taxonomic and functional similarity of bird assemblages. Competition from members of this widespread genus of native honeyeater, rather than landscape structure, was the main cause of both taxonomic and functional homogenization. These species have not recently expanded their range, but rather have increased in density in response to agricultural landscape change. The negative impacts of Manorina honeyeaters on assemblage similarity were most pronounced in landscapes of moderate land-use intensity. We conclude that in these human-modified landscapes, increased competition from dominant native species, or ‘winners’, can result in homogeneous avian assemblages and the loss of specialist species. These interacting processes make biotic homogenization resulting from land-use change a global threat to biodiversity in modified agro-ecosystems. PMID:23724136

  10. Interspecific competition for shelters in territorial and gregarious intertidal grazers: consequences for individual behaviour.

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    Moisés A Aguilera

    Full Text Available Experiments have shown that interspecific interactions within consumer guilds can alter patterns of distribution, abundance and size of species. Plastic behavioural responses can be modulated by agonistic interactions. In many cases, consumers compete for space and shelters, and these interactions change the manner in which they exploit food. This study investigates the consequences of competition in the spatial and temporal organization of behaviour of intertidal grazers, which share algal resources and the use of rock crevices while resting, but exhibit different body sizes, spatial behaviour and foraging modes. We evaluate interaction strength between small gregarious Siphonaria lessoni and the larger territorial keyhole limpet Fissurella crassa and between S. lessoni and the medium-size gregarious chiton Chiton granosus. Using field manipulations and artificial arenas in the laboratory, we tested whether the use of crevices, micro-spatial distribution and activity are modified by the density of conspecifics and the presence of heterospecifics. Our results show that small-scale spatial segregation observed in the field between S. lessoni and C. granosus result from species-specific differences in habitat use. In turn, we found evidence that spatial segregation between F. crassa and S. lessoni results from highly asymmetric interference competition in the use of shelters. The presence of F. crassa reduced the use of crevices and growth rates of S. lessoni. Effects on growth rates are assumed to result from exposure to harsh environmental conditions rather than food limitation. Thus, neither gregarious behaviour nor differences in activity were sufficient to prevent competition with the larger grazer. Our study illustrates the importance of competition for shelters, which results in behavioural changes of the smaller-sized species, and how these plastic responses can translate into differences in growth rates. Use of shelters can thus be

  11. Different intra- and interspecific facilitation mechanisms between two Mediterranean trees under a climate change scenario.

    Science.gov (United States)

    Gimeno, Teresa E; Escudero, Adrián; Valladares, Fernando

    2015-01-01

    In harsh environments facilitation alleviates biotic and abiotic constraints on tree recruitment. Under ongoing drier climate change, we expect facilitation to increase as a driver of coexistence. However, this might not hold under extreme abiotic stress and when the outcome depends on the interaction with other drivers such as altered herbivore pressure due to land use change. We performed a field water-manipulation experiment to quantify the importance of facilitation in two coexisting Mediterranean trees (dominant Juniperus thurifera and coexisting Quercus ilex subsp. ballota) under a climate change scenario. Shifts in canopy dominance favouring Q. ilex could be based on the extension of heterospecific facilitation to the detriment of conspecific alleviation. We found that saplings of both species transplanted under the canopy of nurse trees had greater survival probability, growth and photochemical efficiency. Intra- and interspecific facilitation mechanisms differed: alleviation of abiotic stress benefited both species during summer and J. thurifera during winter, whereas browsing protection was relevant only for Q. ilex. Facilitation was greater under the dry treatment only for Q. ilex, which partially agreed with the predictions of the stress gradient hypothesis. We conclude that present rainfall availability limits neither J. thurifera nor Q. ilex establishment. Nevertheless, under current global change scenarios, imposing increasing abiotic stress together with altered herbivore browsing, nurse trees could differentially facilitate the establishment of Q. ilex due to species-specific traits, i.e. palatability; drought, heat and cold tolerance, underlying species differences in the facilitation mechanisms and eventually triggering a change from pure juniper woodlands to mixed formations.

  12. In situ cardiac perfusion reveals interspecific variation of intraventricular flow separation in reptiles.

    Science.gov (United States)

    Joyce, William; Axelsson, Michael; Altimiras, Jordi; Wang, Tobias

    2016-07-15

    The ventricles of non-crocodilian reptiles are incompletely divided and provide an opportunity for mixing of oxygen-poor blood and oxygen-rich blood (intracardiac shunting). However, both cardiac morphology and in vivo shunting patterns exhibit considerable interspecific variation within reptiles. In the present study, we develop an in situ double-perfused heart approach to characterise the propensity and capacity for shunting in five reptile species: the turtle Trachemys scripta, the rock python Python sebae, the yellow anaconda Eunectes notaeus, the varanid lizard Varanus exanthematicus and the bearded dragon Pogona vitticeps To simulate changes in vascular bed resistance, pulmonary and systemic afterloads were independently manipulated and changes in blood flow distribution amongst the central outflow tracts were monitored. As previously demonstrated in Burmese pythons, rock pythons and varanid lizards exhibited pronounced intraventricular flow separation. As pulmonary or systemic afterload was raised, flow in the respective circulation decreased. However, flow in the other circulation, where afterload was constant, remained stable. This correlates with the convergent evolution of intraventricular pressure separation and the large intraventricular muscular ridge, which compartmentalises the ventricle, in these species. Conversely, in the three other species, the pulmonary and systemic flows were strongly mutually dependent, such that the decrease in pulmonary flow in response to elevated pulmonary afterload resulted in redistribution of perfusate to the systemic circuit (and vice versa). Thus, in these species, the muscular ridge appeared labile and blood could readily transverse the intraventricular cava. We conclude that relatively minor structural differences between non-crocodilian reptiles result in the fundamental changes in cardiac function. Further, our study emphasises that functionally similar intracardiac flow separation evolved independently in

  13. Interspecific variation in life history relates to antipredator decisions by marine mesopredators on temperate reefs.

    Science.gov (United States)

    Frid, Alejandro; Marliave, Jeff; Heithaus, Michael R

    2012-01-01

    As upper-level predatory fishes become overfished, mesopredators rise to become the new 'top' predators of over-exploited marine communities. To gain insight into ensuing mechanisms that might alter indirect species interactions, we examined how behavioural responses to an upper-level predatory fish might differ between mesopredator species with different life histories. In rocky reefs of the northeast Pacific Ocean, adult lingcod (Ophiodon elongatus) are upper-level predators that use a sit-and-wait hunting mode. Reef mesopredators that are prey to adult lingcod include kelp greenling (Hexagrammos decagrammus), younger lingcod, copper rockfish (Sebastes caurinus) and quillback rockfish (S. maliger). Across these mesopredators species, longevity and age at maturity increases and, consequently, the annual proportion of lifetime reproductive output decreases in the order just listed. Therefore, we hypothesized that the level of risk taken to acquire resources would vary interspecifically in that same order. During field experiments we manipulated predation risk with a model adult lingcod and used fixed video cameras to quantify interactions between mesopredators and tethered prey (Pandalus shrimps). We predicted that the probabilities of inspecting and attacking tethered prey would rank from highest to lowest and the timing of these behaviours would rank from earliest to latest as follows: kelp greenling, lingcod, copper rockfish, and quillback rockfish. We also predicted that responses to the model lingcod, such as avoidance of interactions with tethered prey, would rank from weakest to strongest in the same order. Results were consistent with our predictions suggesting that, despite occupying similar trophic levels, longer-lived mesopredators with late maturity have stronger antipredator responses and therefore experience lower foraging rates in the presence of predators than mesopredators with faster life histories. The corollary is that the fishery removal of top

  14. Constitutive type VI secretion system expression gives Vibrio cholerae intra- and interspecific competitive advantages.

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    Daniel Unterweger

    Full Text Available The type VI secretion system (T6SS mediates protein translocation across the cell membrane of Gram-negative bacteria, including Vibrio cholerae - the causative agent of cholera. All V. cholerae strains examined to date harbor gene clusters encoding a T6SS. Structural similarity and sequence homology between components of the T6SS and the T4 bacteriophage cell-puncturing device suggest that the T6SS functions as a contractile molecular syringe to inject effector molecules into prokaryotic and eukaryotic target cells. Regulation of the T6SS is critical. A subset of V. cholerae strains, including the clinical O37 serogroup strain V52, express T6SS constitutively. In contrast, pandemic strains impose tight control that can be genetically disrupted: mutations in the quorum sensing gene luxO and the newly described regulator gene tsrA lead to constitutive T6SS expression in the El Tor strain C6706. In this report, we examined environmental V. cholerae isolates from the Rio Grande with regard to T6SS regulation. Rough V. cholerae lacking O-antigen carried a nonsense mutation in the gene encoding the global T6SS regulator VasH and did not display virulent behavior towards Escherichia coli and other environmental bacteria. In contrast, smooth V. cholerae strains engaged constitutively in type VI-mediated secretion and displayed virulence towards prokaryotes (E. coli and other environmental bacteria and a eukaryote (the social amoeba Dictyostelium discoideum. Furthermore, smooth V. cholerae strains were able to outcompete each other in a T6SS-dependent manner. The work presented here suggests that constitutive T6SS expression provides V. cholerae with an advantage in intraspecific and interspecific competition.

  15. Bathymetric and interspecific variability in maternal reproductive investment and diet of eurybathic echinoderms

    Science.gov (United States)

    Ross, David A. N.; Hamel, Jean-François; Mercier, Annie

    2013-10-01

    While conditions in shallow-water and deep-sea environments differ markedly, it remains unclear how eurybathic species adapt their life histories to cope with these changes. The present study compared indicators of maternal reproductive investment of three common echinoderms collected shallower than 20 m and deeper than 850 m: Cucumaria frondosa (Holothuroidea), Solaster endeca and Henricia sanguinolenta (Asteroidea). Depth-specific and species-specific differences were found in gonad indices (GI), potential fecundity, oocyte size frequency, as well as lipid classes and fatty acids measured in gonad tissue and oocytes. The asteroids, S. endeca and H. sanguinolenta, exemplified the interspecific trade-off between size and number of oocytes: the former had fewer larger oocytes than the latter, with higher total lipid proportions in them. However, intraspecifically, larger oocytes found in deep specimens of S. endeca did not translate into lower fecundity but rather into a seemingly higher GI, indicating greater investment per oocyte without reducing fecundity. Oocytes were absent in specimens of C. frondosa sampled in deep water, suggesting delayed or impaired maturation at the limit of their depth tolerance. Analysis of S. endeca sterol proportions in gonads and oocytes across depths showed higher sterol input into oocytes in females from the deep. Gonads of S. endeca and H. sanguinolenta contained similar essential fatty acids, but showed significant differences in major fatty acids and some of the less dominant ones, indicating diet specificities. Analyses within S. endeca showed evidence of similar feeding mode (carnivory) at both depths, but suggested shifts in the diet or synthesis of fatty acids, presumably reflecting differences in available food sources and/or adaptations to their respective environments.

  16. Interspecific correlates of plasticity in relative growth rate following a decrease in nitrogen availability.

    Science.gov (United States)

    Useche, Antonio; Shipley, Bill

    2010-02-01

    Nitrogen availability varies greatly over short time scales. This requires that a well-adapted plant modify its phenotype by an appropriate amount and at a certain speed in order to maximize growth and fitness. To determine how plastic ontogenetic changes in each trait interact and whether or not these changes are likely to maximize growth, ontogenetic changes in relative growth rate (RGR), net assimilation rate (NAR), specific leaf area (SLA) and root weight ratio (RWR), before and after a decrease in nitrogen supply, were studied in 14 herbaceous species. Forty-four plants of each species were grown in hydroponic culture under controlled conditions in a control treatment where the supply of nitrogen remained constant at 1 mm, and in a stress treatment where the nitrogen supply was abruptly decreased from 1 to 0.01 mm during the growth period. In the treatment series, and in comparison with the control, NAR and RGR decreased, RWR increased, and SLA did not change except for the timing of ontogenetic change. Species having greater increases in the maximum rate of change in RWR also had smaller reductions in RGR; plasticity in RWR is therefore adaptive. In contrast, species which showed a greater decrease in NAR showed stronger reductions in RGR; plasticity in NAR is therefore not adaptive. Plasticity in RGR was not related to plasticity in SLA. There were no significant relationships among the plasticities in NAR, RWR or SLA. Potentially fast-growing species experienced larger reductions in RGR following the nitrogen reduction. These results suggest that competitive responses to interspecific competition for nitrogen might be positively correlated with the plasticity in the maximum rate of change in RWR in response to a reduction in nitrogen supply.

  17. Interspecific variation in prey capture behavior by co-occurring Nepenthes pitcher plants

    Science.gov (United States)

    Chin, Lijin; Chung, Arthur YC; Clarke, Charles

    2014-01-01

    Pitcher plants of the genus Nepenthes capture a wide range of arthropod prey for nutritional benefit, using complex combinations of visual and olfactory signals and gravity-driven pitfall trapping mechanisms. In many localities throughout Southeast Asia, several Nepenthes different species occur in mixed populations. Often, the species present at any given location have strongly divergent trap structures and preliminary surveys indicate that different species trap different combinations of arthropod prey, even when growing at the same locality. On this basis, it has been proposed that co-existing Nepenthes species may be engaged in niche segregation with regards to arthropod prey, avoiding direct competition with congeners by deploying traps that have modifications that enable them to target specific prey types. We examined prey capture among 3 multi-species Nepenthes populations in Borneo, finding that co-existing Nepenthes species do capture different combinations of prey, but that significant interspecific variations in arthropod prey combinations can often be detected only at sub-ordinal taxonomic ranks. In all lowland Nepenthes species examined, the dominant prey taxon is Formicidae, but montane Nepenthes trap few (or no) ants and 2 of the 3 species studied have evolved to target alternative sources of nutrition, such as tree shrew feces. Using similarity and null model analyses, we detected evidence for niche segregation with regards to formicid prey among 5 lowland, sympatric Nepenthes species in Sarawak. However, we were unable to determine whether these results provide support for the niche segregation hypothesis, or whether they simply reflect unquantified variation in heterogeneous habitats and/or ant communities in the study sites. These findings are used to propose improvements to the design of field experiments that seek to test hypotheses about targeted prey capture patterns in Nepenthes. PMID:24481246

  18. Seasonal Occurrence and Interspecific Interactions of Egg Parasitoids of Megacopta cribraria (Heteroptera: Plataspidae) in Japan.

    Science.gov (United States)

    Hoshino, Keisuke; Adati, Tarô; Olson, Dawn M; Takasu, Keiji

    2017-06-01

    We conducted a field study to determine seasonal egg parasitism rates of the kudzu bug Megacopta cribraria (F.) on the kudzu plant, Pueraria montana (Lour.) Merr. var. lobata (Willd.) Maesen et Almeida ex Sanjappa and Pradeep, in Tokyo, Japan, during the period from May 2014 to September 2014. The eggs of M. cribraria per 1 m2 of kudzu at four locations in Tokyo were collected weekly and parasitism rates were assessed. Eggs of M. cribraria were laid on the kudzu plant from May to September. Megacopta cribraria eggs were parasitized by two parasitoid species, Paratelenomus saccharalis (Dodd) and Ooencyrtus nezarae Ishii. Paratelenomus saccharalis first appeared in May, and its parasitism rates peaked in July and September. Ooencyrtus nezarae first appeared in June and its parasitism rates peaked in July. Except for one location which could not be statistically analyzed because of the small sample size, occurrence of parasitism by P. saccharalis and O. nezarae in M. cribraria egg masses was independent at one location and positively associated at two locations, suggesting that the use of host egg masses by P. saccharalis and O. nezarae is not mutually exclusive. Parasitism rates by P. saccharalis and O. nezarae were significantly lower for egg masses parasitized by both species than for those parasitized by a single species. The proportion of males among O. nezarae progeny was significantly higher for egg masses parasitized by O. nezarae together with P. saccharalis than for those parasitized by O. nezarae alone. These results suggest that parasitism of host egg masses by the two species is influenced by their interspecific interactions. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Mechanosensing of stem bending and its interspecific variability in five neotropical rainforest species.

    Science.gov (United States)

    Coutand, Catherine; Chevolot, Malia; Lacointe, André; Rowe, Nick; Scotti, Ivan

    2010-02-01

    In rain forests, sapling survival is highly dependent on the regulation of trunk slenderness (height/diameter ratio): shade-intolerant species have to grow in height as fast as possible to reach the canopy but also have to withstand mechanical loadings (wind and their own weight) to avoid buckling. Recent studies suggest that mechanosensing is essential to control tree dimensions and stability-related morphogenesis. Differences in species slenderness have been observed among rainforest trees; the present study thus investigates whether species with different slenderness and growth habits exhibit differences in mechanosensitivity. Recent studies have led to a model of mechanosensing (sum-of-strains model) that predicts a quantitative relationship between the applied sum of longitudinal strains and the plant's responses in the case of a single bending. Saplings of five different neotropical species (Eperua falcata, E. grandiflora, Tachigali melinonii, Symphonia globulifera and Bauhinia guianensis) were subjected to a regimen of controlled mechanical loading phases (bending) alternating with still phases over a period of 2 months. Mechanical loading was controlled in terms of strains and the five species were subjected to the same range of sum of strains. The application of the sum-of-strain model led to a dose-response curve for each species. Dose-response curves were then compared between tested species. The model of mechanosensing (sum-of-strain model) applied in the case of multiple bending as long as the bending frequency was low. A comparison of dose-response curves for each species demonstrated differences in the stimulus threshold, suggesting two groups of responses among the species. Interestingly, the liana species B. guianensis exhibited a higher threshold than other Leguminosae species tested. This study provides a conceptual framework to study variability in plant mechanosensing and demonstrated interspecific variability in mechanosensing.

  20. [Prevalence of barriers for physical activity in adolescents].

    Science.gov (United States)

    Santos, Mariana Silva; Hino, Adriano Akira Ferreira; Reis, Rodrigo Siqueira; Rodriguez-Añez, Ciro Romélio

    2010-03-01

    The aim of this study was to analyze the prevalence and association of barriers to physical activity among adolescents. This cross-sectional study evaluated a representative sample of public high school students in Curitiba-PR, Brazil. A total of 1,609 school adolescents (59.7% male) between 14 and 18 years of age answered a questionnaire on physical activity status and barriers to physical activity. Logistic regressions were conducted for each barrier investigated to verify the association between the prevalence of barriers and physical activity, adjusting for confounding variables (age and socioeconomic status). Analyses were done separately for boys and girls. Only 22% of boys and 9% of girls achieved the current physical activity recommendation. Among the 12 barriers investigated, only "there is nobody to take" did not differ between boys and girls. The perception of barriers was higher for girls than boys (p barriers. "Lack of friends company" and "feel lazy" were the barriers most often reported by boys (30.4%) and girls (51.8%) respectively; however, the barrier most strongly associated with prevalence of physical inactivity was "prefer to do other things" for both boys (OR = 5.02 (2.69 - 9.37); p barriers for the practice of physical activity were more prevalent in girls and differed as to the extent of importance between genders.

  1. Barriers to medical error reporting

    Directory of Open Access Journals (Sweden)

    Jalal Poorolajal

    2015-01-01

    Full Text Available Background: This study was conducted to explore the prevalence of medical error underreporting and associated barriers. Methods: This cross-sectional study was performed from September to December 2012. Five hospitals, affiliated with Hamadan University of Medical Sciences, in Hamedan,Iran were investigated. A self-administered questionnaire was used for data collection. Participants consisted of physicians, nurses, midwives, residents, interns, and staffs of radiology and laboratory departments. Results: Overall, 50.26% of subjects had committed but not reported medical errors. The main reasons mentioned for underreporting were lack of effective medical error reporting system (60.0%, lack of proper reporting form (51.8%, lack of peer supporting a person who has committed an error (56.0%, and lack of personal attention to the importance of medical errors (62.9%. The rate of committing medical errors was higher in men (71.4%, age of 50-40 years (67.6%, less-experienced personnel (58.7%, educational level of MSc (87.5%, and staff of radiology department (88.9%. Conclusions: This study outlined the main barriers to reporting medical errors and associated factors that may be helpful for healthcare organizations in improving medical error reporting as an essential component for patient safety enhancement.

  2. Sub-barrier photofission of 238U

    International Nuclear Information System (INIS)

    Bhandari, B.S.

    Photofission cross section of 238 U below threshold have been calculated using a double humped potential barrier parameterized by smoothly joining four parabolas, and a coulomb potential at and beyond the scission point. Relative strength in the fission channel has been calculated and an attempt has been made to interpret the apparent resonance structures observed recently in photofission experiments of 238 U as excited states of the fission isomer. A set of parameters for a double humped barrier are found which are consistent with known spontaneous fission and isomeric fission half lives. In addition to reproducing satisfactorily the observed resonance structure near threshold, the calcu