Gustatory sensitivity and food acceptance in two phylogenetically closely related papilionid species: Papilio hospiton and Papilio machaon.

Science.gov (United States)

Sollai, Giorgia; Tomassini Barbarossa, Iole; Masala, Carla; Solari, Paolo; Crnjar, Roberto

2014-01-01

In herbivorous insects, food selection depends on sensitivity to specific chemical stimuli from host-plants as well as to secondary metabolites (bitter) and to sugars (phagostimulatory). Bitter compounds are noxious, unpalatable or both and evoke an aversive feeding response. Instead, sugars and sugar alcohols play a critical role in determining and enhancing the palatability of foods. We assumed that peripheral taste sensitivity may be related to the width of the host selection. Our model consists of two closely phylogenetically related Papilionid species exhibiting a difference in host plant choice: Papilio hospiton and Papilio machaon. The spike activity of the lateral and medial maxillary styloconic taste sensilla was recorded following stimulation with several carbohydrates, nicotine and NaCl, with the aim of characterizing their gustatory receptor neurons and of comparing their response patterns in the light of their different acceptability in feeding behaviour. The results show that: a) each sensillum houses phagostimulant and phagodeterrent cells; b) the spike activity of the gustatory neurons in response to different taste stimuli is higher in P. hospiton than in P. machaon; c) sugar solutions inhibit the spike activity of the deterrent and salt cells, and the suppression is higher in P. machaon than in P. hospiton. In conclusion, we propose that the different balance between the phagostimulant and phagodeterrent inputs from GRNs of maxillary sensilla may contribute in determining the difference in food choice and host range.

Gustatory sensitivity and food acceptance in two phylogenetically closely related papilionid species: Papilio hospiton and Papilio machaon.

Directory of Open Access Journals (Sweden)

Giorgia Sollai

Full Text Available In herbivorous insects, food selection depends on sensitivity to specific chemical stimuli from host-plants as well as to secondary metabolites (bitter and to sugars (phagostimulatory. Bitter compounds are noxious, unpalatable or both and evoke an aversive feeding response. Instead, sugars and sugar alcohols play a critical role in determining and enhancing the palatability of foods. We assumed that peripheral taste sensitivity may be related to the width of the host selection. Our model consists of two closely phylogenetically related Papilionid species exhibiting a difference in host plant choice: Papilio hospiton and Papilio machaon. The spike activity of the lateral and medial maxillary styloconic taste sensilla was recorded following stimulation with several carbohydrates, nicotine and NaCl, with the aim of characterizing their gustatory receptor neurons and of comparing their response patterns in the light of their different acceptability in feeding behaviour. The results show that: a each sensillum houses phagostimulant and phagodeterrent cells; b the spike activity of the gustatory neurons in response to different taste stimuli is higher in P. hospiton than in P. machaon; c sugar solutions inhibit the spike activity of the deterrent and salt cells, and the suppression is higher in P. machaon than in P. hospiton. In conclusion, we propose that the different balance between the phagostimulant and phagodeterrent inputs from GRNs of maxillary sensilla may contribute in determining the difference in food choice and host range.

Evaluation of γ-radiation-induced DNA damage in two species of bivalves and their relative sensitivity using comet assay.

Science.gov (United States)

Praveen Kumar, M K; Shyama, S K; Sonaye, B S; Naik, U Roshini; Kadam, S B; Bipin, P D; D'costa, A; Chaubey, R C

2014-05-01

Ionizing radiation is known to induce genetic damage in diverse groups of organisms. Under accidental situations, large quantities of radioactive elements get released into the environment and radiation emitted from these radionuclides may adversely affect both the man and the non-human biota. The present study is aimed (a) to know the genotoxic effect of gamma radiation on aquatic fauna employing two species of selected bivalves, (b) to evaluate the possible use of 'Comet assay' for detecting genetic damage in haemocytes of bivalves as a biomarker for environmental biomonitoring and also (c) to compare the relative sensitivity of two species of bivalves viz. Paphia malabarica and Meretrix casta to gamma radiation. The comet assays was optimized and validated using different concentrations (18, 32 and 56 mg/L) of ethyl methanesulfonate (EMS), a direct-acting reference genotoxic agent, to which the bivalves were exposed for various times (24, 48 and 72 h). Bivalves were irradiated (single acute exposure) with 5 different doses (viz. 2, 4, 6, 8 and 10 Gy) of gamma radiation and their genotoxic effects on the haemocytes were studied using the comet assay. Haemolymph was collected from the adductor muscle at 24, 48 and 72 h of both EMS-exposed and irradiated bivalves and comet assay was carried out using standard protocol. A significant increase in DNA damage was observed as indicated by an increase in % tail DNA damage at different concentrations of EMS and all the doses of gamma radiation as compared to controls in both bivalve species. This showed a dose-dependent increase of genetic damage induced in bivalves by EMS as well as gamma radiation. Further, the highest DNA damage was observed at 24h. The damage gradually decreased with time, i.e. was smaller at 48 and 72 h than at 24h post irradiation in both species of bivalves. This may indicate repair of the damaged DNA and/or loss of heavily damaged cells as the post irradiation time advanced. The present study

Species-independent bioassay for sensitive quantification of antiviral type I interferons

Directory of Open Access Journals (Sweden)

Penski Nicola

2010-02-01

Full Text Available Abstract Background Studies of the host response to infection often require quantitative measurement of the antiviral type I interferons (IFN-α/β in biological samples. The amount of IFN is either determined via its ability to suppress a sensitive indicator virus, by an IFN-responding reporter cell line, or by ELISA. These assays however are either time-consuming and lack convenient readouts, or they are rather insensitive and restricted to IFN from a particular host species. Results An IFN-sensitive, Renilla luciferase-expressing Rift Valley fever virus (RVFV-Ren was generated using reverse genetics. Human, murine and avian cells were tested for their susceptibility to RVFV-Ren after treatment with species-specific IFNs. RVFV-Ren was able to infect cells of all three species, and IFN-mediated inhibition of viral reporter activity occurred in a dose-dependent manner. The sensitivity limit was found to be 1 U/ml IFN, and comparison with a standard curve allowed to determine the activity of an unknown sample. Conclusions RVFV-Ren replicates in cells of several species and is highly sensitive to pre-treatment with IFN. These properties allowed the development of a rapid, sensitive, and species-independent antiviral assay with a convenient luciferase-based readout.

Staphylococci Related to Farm Ostriches and Their Sensitivity to Enterocins.

Science.gov (United States)

Kandričáková, Anna; Lauková, Andrea; Ščerbová, Jana

2016-03-01

In Slovakia, ostriches are reared mainly for their meat. There is still limited information related to microflora of ostriches, including staphylococci. Knowing the composition of microflora is very important for the recognition of potential pathogenic agents. Recently, a frequent problem in animals is the occurrence of bacteria resistant to antibiotics. The aim of this study was to detect staphylococcal species in feces of farm ostriches and to test their sensitivity to antibiotics and enterocins. Altogether 140 ostriches from three age groups were sampled (n = 18, faecal mixture samples from each group) on a farm in Slovakia or on Slovak farm. From 54 fecal samples, the staphylococcal count reached an average 4. 3 ± 0. 63 (log10) CFU/g. Twenty-four lactic acid producing strains were taxonomically classified to eight species of the genus Staphylococcus: Staphylococcus equorum, S. xylosus, S. epidermidis, S. haemolyticus, S. cohnii, S. succinus, S. warneri, and S. hominis. Strains were evaluated by secure probable species identification/probable species identification (score value up to 2.299) confirmed also by phenotypization. Most strains were sensitive to antibiotics. Four strains (S. haemolyticus SHae 111, S. haemolyticus SHAe 371, S. xylosus SX 2133, and S. warneri SW 292) were resistant to methicillin but sensitive to six or five of the seven enterocins tested (inhibitory activity 200-12,800 AU/mL). S. warneri SW 292 was sensitive to all enterocins (activity up to 12,800 AU/mL).

Sensitive Multi-Species Emissions Monitoring: Infrared Laser-Based Detection of Trace-Level Contaminants

Energy Technology Data Exchange (ETDEWEB)

Steill, Jeffrey D. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Huang, Haifeng [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Hoops, Alexandra A. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Patterson, Brian D. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Birtola, Salvatore R. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Jaska, Mark [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Strecker, Kevin E. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Chandler, David W. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Bisson, Soott [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

2014-09-01

This report summarizes our development of spectroscopic chemical analysis techniques and spectral modeling for trace-gas measurements of highly-regulated low-concentration species present in flue gas emissions from utility coal boilers such as HCl under conditions of high humidity. Detailed spectral modeling of the spectroscopy of HCl and other important combustion and atmospheric species such as H 2 O, CO 2 , N 2 O, NO 2 , SO 2 , and CH 4 demonstrates that IR-laser spectroscopy is a sensitive multi-component analysis strategy. Experimental measurements from techniques based on IR laser spectroscopy are presented that demonstrate sub-ppm sensitivity levels to these species. Photoacoustic infrared spectroscopy is used to detect and quantify HCl at ppm levels with extremely high signal-to-noise even under conditions of high relative humidity. Additionally, cavity ring-down IR spectroscopy is used to achieve an extremely high sensitivity to combustion trace gases in this spectral region; ppm level CH 4 is one demonstrated example. The importance of spectral resolution in the sensitivity of a trace-gas measurement is examined by spectral modeling in the mid- and near-IR, and efforts to improve measurement resolution through novel instrument development are described. While previous project reports focused on benefits and complexities of the dual-etalon cavity ring-down infrared spectrometer, here details on steps taken to implement this unique and potentially revolutionary instrument are described. This report also illustrates and critiques the general strategy of IR- laser photodetection of trace gases leading to the conclusion that mid-IR laser spectroscopy techniques provide a promising basis for further instrument development and implementation that will enable cost-effective sensitive detection of multiple key contaminant species simultaneously.

Adaptive Management Plan for Sensitive Plant Species on the Nevada Test Site

International Nuclear Information System (INIS)

Wills, C. A.

2001-01-01

The Nevada Test Site supports numerous plant species considered sensitive because of their past or present status under the Endangered Species Act and with federal and state agencies. In 1998, the U.S. Department of Energy, Nevada Operation Office (DOE/NV) prepared a Resource Management Plan which commits to protects and conserve these sensitive plant species and to minimize accumulative impacts to them. This document presents the procedures of a long-term adaptive management plan which is meant to ensure that these goals are met. It identifies the parameters that are measured for all sensitive plant populations during long-term monitoring and the adaptive management actions which may be taken if significant threats to these populations are detected. This plan does not, however, identify the current list of sensitive plant species know to occur on the Nevada Test Site. The current species list and progress on their monitoring is reported annually by DOE/NV in the Resource Management Plan

Using Bioassays and Species Sensitivity Distributions to Assess Herbicide Toxicity towards Benthic Diatoms

Science.gov (United States)

Larras, Floriane; Bouchez, Agnès; Rimet, Frédéric; Montuelle, Bernard

2012-01-01

Although benthic diatoms are widely used in ecological studies of aquatic systems, there is still a dearth of data concerning species sensitivities towards several contaminants. Within the same community, different species may respond differently depending on their physiological and ecological characteristics. This lack of knowledge makes specific appropriate risk assessment impossible. To find out whether species sensitivity distribution (SSD) could be used to estimate the risk of herbicide toxicity for diatoms, we need to know whether their sensitivity depends on their physiological and ecological characteristics. We carried out single-species bioassays on 11 diatom species exposed to 8 herbicides. Dose-responses relationships were used to extrapolate the Effective Concentration 5 (EC5) and the Effective Concentration 50 (EC50) for each exposure. These data were used to fit a SSD curve for each herbicide, and to determine the Hazardous concentration 5 (HC5) and 50 (HC50). Our results revealed a high level of variability of the sensitivity in the set of species tested. For photosystem-II inhibitor (PSII) herbicides, diatoms species displayed a typical grouping of sensitivity levels consistent with their trophic mode and their ecological guild. N-heterotroph and “motile” guild species were more tolerant of PSII inhibitors, while N-autotroph and “low profile” guild species were more sensitive. Comprehensive SSD curves were obtained for 5 herbicides, but not for sulfonylurea herbicides or for dimetachlor, which had toxicity levels that were below the range of concentration tested. The SSD curves provided the following ranking of toxicity: diuron> terbutryn> isoproturon> atrazine> metolachlor. The HC that affected 5% of the species revealed that, even at the usual environmental concentrations of herbicides, diatom assemblages could be affected, especially by isoproturon, terbutryn, and diuron. PMID:22952981

Using bioassays and species sensitivity distributions to assess herbicide toxicity towards benthic diatoms.

Directory of Open Access Journals (Sweden)

Floriane Larras

Full Text Available Although benthic diatoms are widely used in ecological studies of aquatic systems, there is still a dearth of data concerning species sensitivities towards several contaminants. Within the same community, different species may respond differently depending on their physiological and ecological characteristics. This lack of knowledge makes specific appropriate risk assessment impossible. To find out whether species sensitivity distribution (SSD could be used to estimate the risk of herbicide toxicity for diatoms, we need to know whether their sensitivity depends on their physiological and ecological characteristics. We carried out single-species bioassays on 11 diatom species exposed to 8 herbicides. Dose-responses relationships were used to extrapolate the Effective Concentration 5 (EC(5 and the Effective Concentration 50 (EC(50 for each exposure. These data were used to fit a SSD curve for each herbicide, and to determine the Hazardous concentration 5 (HC(5 and 50 (HC(50. Our results revealed a high level of variability of the sensitivity in the set of species tested. For photosystem-II inhibitor (PSII herbicides, diatoms species displayed a typical grouping of sensitivity levels consistent with their trophic mode and their ecological guild. N-heterotroph and "motile" guild species were more tolerant of PSII inhibitors, while N-autotroph and "low profile" guild species were more sensitive. Comprehensive SSD curves were obtained for 5 herbicides, but not for sulfonylurea herbicides or for dimetachlor, which had toxicity levels that were below the range of concentration tested. The SSD curves provided the following ranking of toxicity: diuron> terbutryn> isoproturon> atrazine> metolachlor. The HC that affected 5% of the species revealed that, even at the usual environmental concentrations of herbicides, diatom assemblages could be affected, especially by isoproturon, terbutryn, and diuron.

Species composition and forest structure explain the temperature sensitivity patterns of productivity in temperate forests

Directory of Open Access Journals (Sweden)

F. J. Bohn

2018-03-01

Full Text Available Rising temperatures due to climate change influence the wood production of forests. Observations show that some temperate forests increase their productivity, whereas others reduce their productivity. This study focuses on how species composition and forest structure properties influence the temperature sensitivity of aboveground wood production (AWP. It further investigates which forests will increase their productivity the most with rising temperatures. We described forest structure by leaf area index, forest height and tree height heterogeneity. Species composition was described by a functional diversity index (Rao's Q and a species distribution index (ΩAWP. ΩAWP quantified how well species are distributed over the different forest layers with regard to AWP. We analysed 370 170 forest stands generated with a forest gap model. These forest stands covered a wide range of possible forest types. For each stand, we estimated annual aboveground wood production and performed a climate sensitivity analysis based on 320 different climate time series (of 1-year length. The scenarios differed in mean annual temperature and annual temperature amplitude. Temperature sensitivity of wood production was quantified as the relative change in productivity resulting from a 1 °C rise in mean annual temperature or annual temperature amplitude. Increasing ΩAWP positively influenced both temperature sensitivity indices of forest, whereas forest height showed a bell-shaped relationship with both indices. Further, we found forests in each successional stage that are positively affected by temperature rise. For such forests, large ΩAWP values were important. In the case of young forests, low functional diversity and small tree height heterogeneity were associated with a positive effect of temperature on wood production. During later successional stages, higher species diversity and larger tree height heterogeneity were an advantage. To achieve such a

Species composition and forest structure explain the temperature sensitivity patterns of productivity in temperate forests

Science.gov (United States)

Bohn, Friedrich J.; May, Felix; Huth, Andreas

2018-03-01

Rising temperatures due to climate change influence the wood production of forests. Observations show that some temperate forests increase their productivity, whereas others reduce their productivity. This study focuses on how species composition and forest structure properties influence the temperature sensitivity of aboveground wood production (AWP). It further investigates which forests will increase their productivity the most with rising temperatures. We described forest structure by leaf area index, forest height and tree height heterogeneity. Species composition was described by a functional diversity index (Rao's Q) and a species distribution index (ΩAWP). ΩAWP quantified how well species are distributed over the different forest layers with regard to AWP. We analysed 370 170 forest stands generated with a forest gap model. These forest stands covered a wide range of possible forest types. For each stand, we estimated annual aboveground wood production and performed a climate sensitivity analysis based on 320 different climate time series (of 1-year length). The scenarios differed in mean annual temperature and annual temperature amplitude. Temperature sensitivity of wood production was quantified as the relative change in productivity resulting from a 1 °C rise in mean annual temperature or annual temperature amplitude. Increasing ΩAWP positively influenced both temperature sensitivity indices of forest, whereas forest height showed a bell-shaped relationship with both indices. Further, we found forests in each successional stage that are positively affected by temperature rise. For such forests, large ΩAWP values were important. In the case of young forests, low functional diversity and small tree height heterogeneity were associated with a positive effect of temperature on wood production. During later successional stages, higher species diversity and larger tree height heterogeneity were an advantage. To achieve such a development, one could plant

The importance of ultraviolet and near-infrared sensitivity for visual discrimination in two species of lacertid lizards.

Science.gov (United States)

Martin, Mélissa; Le Galliard, Jean-François; Meylan, Sandrine; Loew, Ellis R

2015-02-01

Male and female Lacertid lizards often display conspicuous coloration that is involved in intraspecific communication. However, visual systems of Lacertidae have rarely been studied and the spectral sensitivity of their retinal photoreceptors remains unknown. Here, we characterise the spectral sensitivity of two Lacertid species from contrasting habitats: the wall lizard Podarcis muralis and the common lizard Zootoca vivipara. Both species possess a pure-cone retina with one spectral class of double cones and four spectral classes of single cones. The two species differ in the spectral sensitivity of the LWS cones, the relative abundance of UVS single cones (potentially more abundant in Z. vivipara) and the coloration of oil droplets. Wall lizards have pure vitamin A1-based photopigments, whereas common lizards possess mixed vitamin A1 and A2 photopigments, extending spectral sensitivity into the near infrared, which is a rare feature in terrestrial vertebrates. We found that spectral sensitivity in the UV and near infrared improves discrimination of small variations in throat coloration among Z. vivipara. Thus, retinal specialisations optimise chromatic resolution in common lizards, indicating that the visual system and visual signals might co-evolve. © 2015. Published by The Company of Biologists Ltd.

Species-Specific Antimonial Sensitivity in Leishmania Is Driven by Post-Transcriptional Regulation of AQP1

Science.gov (United States)

Mandal, Goutam; Mandal, Srotoswati; Sharma, Mansi; Charret, Karen Santos; Papadopoulou, Barbara; Bhattacharjee, Hiranmoy; Mukhopadhyay, Rita

2015-01-01

Leishmania is a digenetic protozoan parasite causing leishmaniasis in humans. The different clinical forms of leishmaniasis are caused by more than twenty species of Leishmania that are transmitted by nearly thirty species of phlebotomine sand flies. Pentavalent antimonials (such as Pentostam or Glucantime) are the first line drugs for treating leishmaniasis. Recent studies suggest that pentavalent antimony (Sb(V)) acts as a pro-drug, which is converted to the more active trivalent form (Sb(III)). However, sensitivity to trivalent antimony varies among different Leishmania species. In general, Leishmania species causing cutaneous leishmaniasis (CL) are more sensitive to Sb(III) than the species responsible for visceral leishmaniasis (VL). Leishmania aquaglyceroporin (AQP1) facilitates the adventitious passage of antimonite down a concentration gradient. In this study, we show that Leishmania species causing CL accumulate more antimonite, and therefore exhibit higher sensitivity to antimonials, than the species responsible for VL. This species-specific differential sensitivity to antimonite is directly proportional to the expression levels of AQP1 mRNA. We show that the stability of AQP1 mRNA in different Leishmania species is regulated by their respective 3’-untranslated regions. The differential regulation of AQP1 mRNA explains the distinct antimonial sensitivity of each species. PMID:25714343

Contrasting ozone sensitivity in related evergreen and deciduous shrubs

International Nuclear Information System (INIS)

Calatayud, Vicent; Marco, Francisco; Cervero, Julia; Sanchez-Pena, Gerardo; Sanz, Maria Jose

2010-01-01

Plant responses to enhanced ozone levels have been studied in two pairs of evergreen-deciduous species (Pistacia terebinthus vs. P. lentiscus; Viburnum lantana vs. V. tinus) in Open Top Chambers. Ozone induced widespread visible injury, significantly reduced CO 2 assimilation and stomatal conductance (g s ), impaired Rubisco efficiency and regeneration capacity (V c,max, J max ) and altered fluorescence parameters only in the deciduous species. Differences in stomatal conductance could not explain the observed differences in sensitivity. In control plants, deciduous species showed higher superoxide dismutase (SOD) activity than their evergreen counterparts, suggesting metabolic differences that could make them more prone to redox imbalances. Ozone induced increases in SOD and/or peroxidase activities in all the species, but only evergreens were able to cope with the oxidative stress. The relevancy of these results for the effective ozone flux approach and for the current ozone Critical Levels is also discussed. - Mediterranean evergreen shrubs have a constitutively higher capacity to tolerate ozone stress than their deciduous relatives.

Foliar Nutrient Distribution Patterns in Sympatric Maple Species Reflect Contrasting Sensitivity to Excess Manganese.

Science.gov (United States)

Fernando, Denise R; Marshall, Alan T; Lynch, Jonathan P

2016-01-01

Sugar maple and red maple are closely-related co-occurring tree species significant to the North American forest biome. Plant abiotic stress effects including nutritional imbalance and manganese (Mn) toxicity are well documented within this system, and are implicated in enhanced susceptibility to biotic stresses such as insect attack. Both tree species are known to overaccumulate foliar manganese (Mn) when growing on unbuffered acidified soils, however, sugar maple is Mn-sensitive, while red maple is not. Currently there is no knowledge about the cellular sequestration of Mn and other nutrients in these two species. Here, electron-probe x-ray microanalysis was employed to examine cellular and sub-cellular deposition of excessively accumulated foliar Mn and other mineral nutrients in vivo. For both species, excess foliar Mn was deposited in symplastic cellular compartments. There were striking between-species differences in Mn, magnesium (Mg), sulphur (S) and calcium (Ca) distribution patterns. Unusually, Mn was highly co-localised with Mg in mesophyll cells of red maple only. The known sensitivity of sugar maple to excess Mn is likely linked to Mg deficiency in the leaf mesophyll. There was strong evidence that Mn toxicity in sugar maple is primarily a symplastic process. For each species, leaf-surface damage due to biotic stress including insect herbivory was compared between sites with acidified and non-acidified soils. Although it was greatest overall in red maple, there was no difference in biotic stress damage to red maple leaves between acidified and non-acidified soils. Sugar maple trees on buffered non-acidified soil were less damaged by biotic stress compared to those on unbuffered acidified soil, where they are also affected by Mn toxicity abiotic stress. This study concluded that foliar nutrient distribution in symplastic compartments is a determinant of Mn sensitivity, and that Mn stress hinders plant resistance to biotic stress.

Acute sensitivity of three Cladoceran species to different types of microplastics in combination with thermal stress.

Science.gov (United States)

Jaikumar, Gayathri; Baas, Jan; Brun, Nadja R; Vijver, Martina G; Bosker, Thijs

2018-08-01

Microplastics (microplastics on freshwater ecosystems, especially under different environmental conditions. In the present study, the sensitivity of two temperate Cladoceran species, Daphnia magna and Daphnia pulex, and a smaller tropical species Ceriodaphnia dubia, to primary microplastics (PMP) and secondary (weathered) microplastics (SMP) was assessed. A prolonged acute toxicity assay (up to 72 or 96 h) was performed at 18°, 22°, and 26 °C, to determine the influence of temperature as an additional stressor and survival data were analysed using toxicokinetic-toxicodynamic (TK-TD) model. Acute sensitivity of D. magna and D. pulex to both PMP and SMP increased sharply with temperature, whereas that of C. dubia remained relatively stable across temperatures. C. dubia was the most sensitive species at 18 °C, followed by D. pulex and D. magna, which were of comparable sensitivity. However, this ranking was reversed at 26 °C as could be seen from the No Effect Concentration (NEC) estimates of the TK-TD model. In addition, SMP and PMP had a similar effect on D. magna and D. pulex, but PMP was more toxic to C. dubia. Effects on survival were strongly time-dependent and became substantially more severe after the standard 48 h test period. Our results indicate that sensitivity to microplastics may differ between species for different types of microplastics, and could be drastically influenced by temperature albeit at high exposure concentrations. Copyright © 2018 Elsevier Ltd. All rights reserved.

Providing the Air Force with Data on Species Sensitive to Noise from Low Flying Aircraft

National Research Council Canada - National Science Library

Howie, Shara

2000-01-01

...), the ACC must evaluate its air operations for impacts to noise sensitive wildlife. The areas used for training flights change, the list of species believed sensitive to noise changes, the species and the species information are dynamic...

Validity and sensitivity of a model for assessment of impacts of river floodplain reconstruction on protected and endangered species

International Nuclear Information System (INIS)

Nooij, R.J.W. de; Lotterman, K.M.; Sande, P.H.J. van de; Pelsma, T.; Leuven, R.S.E.W.; Lenders, H.J.R.

2006-01-01

Environmental Impact Assessment (EIA) must account for legally protected and endangered species. Uncertainties relating to the validity and sensitivity of EIA arise from predictions and valuation of effects on these species. This paper presents a validity and sensitivity analysis of a model (BIO-SAFE) for assessment of impacts of land use changes and physical reconstruction measures on legally protected and endangered river species. The assessment is based on links between species (higher plants, birds, mammals, reptiles and amphibians, butterflies and dragon- and damselflies) and ecotopes (landscape ecological units, e.g., river dune, soft wood alluvial forests), and on value assignment to protected and endangered species using different valuation criteria (i.e., EU Habitats and Birds directive, Conventions of Bern and Bonn and Red Lists). The validity of BIO-SAFE has been tested by comparing predicted effects of landscape changes on the diversity of protected and endangered species with observed changes in biodiversity in five reconstructed floodplains. The sensitivity of BIO-SAFE to value assignment has been analysed using data of a Strategic Environmental Assessment concerning the Spatial Planning Key Decision for reconstruction of the Dutch floodplains of the river Rhine, aimed at flood defence and ecological rehabilitation. The weights given to the valuation criteria for protected and endangered species were varied and the effects on ranking of alternatives were quantified. A statistically significant correlation (p < 0.01) between predicted and observed values for protected and endangered species was found. The sensitivity of the model to value assignment proved to be low. Comparison of five realistic valuation options showed that different rankings of scenarios predominantly occur when valuation criteria are left out of the assessment. Based on these results we conclude that linking species to ecotopes can be used for adequate impact assessments

Hearing sensitivity in context: Conservation implications for a highly vocal endangered species

Directory of Open Access Journals (Sweden)

Megan A. Owen

2016-04-01

Full Text Available Hearing sensitivity is a fundamental determinant of a species’ vulnerability to anthropogenic noise, however little is known about the hearing capacities of most conservation dependent species. When audiometric data are integrated with other aspects of species’ acoustic ecology, life history, and characteristic habitat topography and soundscape, predictions can be made regarding probable vulnerability to the negative impacts of different types of anthropogenic noise. Here we used an adaptive psychoacoustic technique to measure hearing thresholds in the endangered giant panda; a species that uses acoustic communication to coordinate reproduction. Our results suggest that giant pandas have functional hearing into the ultrasonic range, with good sensitivity between 10.0 and 16.0 kHz, and best sensitivity measured at 12.5–14.0 kHz. We estimated the lower and upper limits of functional hearing as 0.10 and 70.0 kHz respectively. While these results suggest that panda hearing is similar to that of some other terrestrial carnivores, panda hearing thresholds above 14.0 kHz were significantly lower (i.e., more sensitive than those of the polar bear, the only other bear species for which data are available. We discuss the implications of this divergence, as well as the relationship between hearing sensitivity and the spectral parameters of panda vocalizations. We suggest that these data, placed in context, can be used towards the development of a sensory-based model of noise disturbance for the species.

Contrasting ozone sensitivity in related evergreen and deciduous shrubs

Energy Technology Data Exchange (ETDEWEB)

Calatayud, Vicent, E-mail: vicent@ceam.e [Fundacion CEAM, c/ Charles R. Darwin 14, Parque Tecnologico, 46980 Paterna, Valencia (Spain); Marco, Francisco; Cervero, Julia [Fundacion CEAM, c/ Charles R. Darwin 14, Parque Tecnologico, 46980 Paterna, Valencia (Spain); Sanchez-Pena, Gerardo [SPCAN, Dir. Gral. de Medio Natural y Politica Forestal, Ministerio de Medio Ambiente, y Medio Rural y Marino, Rios Rosas 24, 28003 Madrid (Spain); Sanz, Maria Jose [Fundacion CEAM, c/ Charles R. Darwin 14, Parque Tecnologico, 46980 Paterna, Valencia (Spain)

2010-12-15

Plant responses to enhanced ozone levels have been studied in two pairs of evergreen-deciduous species (Pistacia terebinthus vs. P. lentiscus; Viburnum lantana vs. V. tinus) in Open Top Chambers. Ozone induced widespread visible injury, significantly reduced CO{sub 2} assimilation and stomatal conductance (g{sub s}), impaired Rubisco efficiency and regeneration capacity (V{sub c,max,}J{sub max}) and altered fluorescence parameters only in the deciduous species. Differences in stomatal conductance could not explain the observed differences in sensitivity. In control plants, deciduous species showed higher superoxide dismutase (SOD) activity than their evergreen counterparts, suggesting metabolic differences that could make them more prone to redox imbalances. Ozone induced increases in SOD and/or peroxidase activities in all the species, but only evergreens were able to cope with the oxidative stress. The relevancy of these results for the effective ozone flux approach and for the current ozone Critical Levels is also discussed. - Mediterranean evergreen shrubs have a constitutively higher capacity to tolerate ozone stress than their deciduous relatives.

Alkylation sensitivity screens reveal a conserved cross-species functionome

Science.gov (United States)

Svilar, David; Dyavaiah, Madhu; Brown, Ashley R.; Tang, Jiang-bo; Li, Jianfeng; McDonald, Peter R.; Shun, Tong Ying; Braganza, Andrea; Wang, Xiao-hong; Maniar, Salony; St Croix, Claudette M.; Lazo, John S.; Pollack, Ian F.; Begley, Thomas J.; Sobol, Robert W.

2013-01-01

To identify genes that contribute to chemotherapy resistance in glioblastoma, we conducted a synthetic lethal screen in a chemotherapy-resistant glioblastoma derived cell line with the clinical alkylator temozolomide (TMZ) and an siRNA library tailored towards “druggable” targets. Select DNA repair genes in the screen were validated independently, confirming the DNA glycosylases UNG and MYH as well as MPG to be involved in the response to high dose TMZ. The involvement of UNG and MYH is likely the result of a TMZ-induced burst of reactive oxygen species. We then compared the human TMZ sensitizing genes identified in our screen with those previously identified from alkylator screens conducted in E. coli and S. cerevisiae. The conserved biological processes across all three species composes an Alkylation Functionome that includes many novel proteins not previously thought to impact alkylator resistance. This high-throughput screen, validation and cross-species analysis was then followed by a mechanistic analysis of two essential nodes: base excision repair (BER) DNA glycosylases (UNG, human and mag1, S. cerevisiae) and protein modification systems, including UBE3B and ICMT in human cells or pby1, lip22, stp22 and aim22 in S. cerevisiae. The conserved processes of BER and protein modification were dual targeted and yielded additive sensitization to alkylators in S. cerevisiae. In contrast, dual targeting of BER and protein modification genes in human cells did not increase sensitivity, suggesting an epistatic relationship. Importantly, these studies provide potential new targets to overcome alkylating agent resistance. PMID:23038810

Using citizen science data to identify the sensitivity of species to human land use.

Science.gov (United States)

Todd, Brian D; Rose, Jonathan P; Price, Steven J; Dorcas, Michael E

2016-12-01

Conservation practitioners must contend with an increasing array of threats that affect biodiversity. Citizen scientists can provide timely and expansive information for addressing these threats across large scales, but their data may contain sampling biases. We used randomization procedures to account for possible sampling biases in opportunistically reported citizen science data to identify species' sensitivities to human land use. We analyzed 21,044 records of 143 native reptile and amphibian species reported to the Carolina Herp Atlas from North Carolina and South Carolina between 1 January 1990 and 12 July 2014. Sensitive species significantly associated with natural landscapes were 3.4 times more likely to be legally protected or treated as of conservation concern by state resource agencies than less sensitive species significantly associated with human-dominated landscapes. Many of the species significantly associated with natural landscapes occurred primarily in habitats that had been nearly eradicated or otherwise altered in the Carolinas, including isolated wetlands, longleaf pine savannas, and Appalachian forests. Rare species with few reports were more likely to be associated with natural landscapes and 3.2 times more likely to be legally protected or treated as of conservation concern than species with at least 20 reported occurrences. Our results suggest that opportunistically reported citizen science data can be used to identify sensitive species and that species currently restricted primarily to natural landscapes are likely at greatest risk of decline from future losses of natural habitat. Our approach demonstrates the usefulness of citizen science data in prioritizing conservation and in helping practitioners address species declines and extinctions at large extents. © 2016 Society for Conservation Biology.

Sensitivity of metrics of phylogenetic structure to scale, source of data and species pool of hummingbird assemblages along elevational gradients.

Directory of Open Access Journals (Sweden)

Sebastián González-Caro

Full Text Available Patterns of phylogenetic structure of assemblages are increasingly used to gain insight into the ecological and evolutionary processes involved in the assembly of co-occurring species. Metrics of phylogenetic structure can be sensitive to scaling issues and data availability. Here we empirically assess the sensitivity of four metrics of phylogenetic structure of assemblages to changes in (i the source of data, (ii the spatial grain at which assemblages are defined, and (iii the definition of species pools using hummingbird (Trochilidae assemblages along an elevational gradient in Colombia. We also discuss some of the implications in terms of the potential mechanisms driving these patterns. To explore how source of data influence phylogenetic structure we defined assemblages using three sources of data: field inventories, museum specimens, and range maps. Assemblages were defined at two spatial grains: coarse-grained (elevational bands of 800-m width and fine-grained (1-km(2 plots. We used three different species pools: all species contained in assemblages, all species within half-degree quadrats, and all species either above or below 2000 m elevation. Metrics considering phylogenetic relationships among all species within assemblages showed phylogenetic clustering at high elevations and phylogenetic evenness in the lowlands, whereas those metrics considering only the closest co-occurring relatives showed the opposite trend. This result suggests that using multiple metrics of phylogenetic structure should provide greater insight into the mechanisms shaping assemblage structure. The source and spatial grain of data had important influences on estimates of both richness and phylogenetic structure. Metrics considering the co-occurrence of close relatives were particularly sensitive to changes in the spatial grain. Assemblages based on range maps included more species and showed less phylogenetic structure than assemblages based on museum or field

Development and application of a species sensitivity distribution for temperature-induced mortality in the aquatic environment

NARCIS (Netherlands)

Vries, de P.; Tamis, J.E.; Murk, A.J.; Smit, M.G.D.

2008-01-01

Current European legislation has static water quality objectives for temperature effects, based on the most sensitive species. In the present study a species sensitivity distribution (SSD) for elevated temperatures is developed on the basis of temperature sensitivity data (mortality) of 50 aquatic

Evaluating relative contribution of osmotolerance and tissue tolerance mechanisms toward salinity stress tolerance in three Brassica species.

Science.gov (United States)

Chakraborty, Koushik; Bose, Jayakumar; Shabala, Lana; Eyles, Alieta; Shabala, Sergey

2016-10-01

Three different species of Brassica, with differential salt sensitivity were used to understand physiological mechanisms of salt tolerance operating in these species and to evaluate the relative contribution of different strategies to cope with salt load. Brassica napus was the most tolerant species in terms of the overall performance, with Brassica juncea and Brassica oleracea being much more sensitive to salt stress with no obvious difference between them. While prominent reduction in net CO2 assimilation was observed in both sensitive species, physiological mechanisms beyond this reduction differed strongly. Brassica juncea plants possessed high osmotolerance and were able to maintain high transpiration rate but showed a significant reduction in leaf chlorophyll content and efficiency of leaf photochemistry. On the contrary, B. oleracea plants possessed the highest (among the three species) tissue tolerance but showed a very significant stomatal limitation of photosynthesis. Electrophysiological experiments revealed that the high tissue tolerance in B. oleracea was related to the ability of leaf mesophyll cells to maintain highly negative membrane potential in the presence of high apoplastic Na(+) . In addition to high osmotolerance, the most tolerant B. napus showed also lesser accumulation of toxic Na(+) and Cl(-) in the leaf, possessed moderate tissue tolerance and had a superior K(+) retention ability. Taken together, the results from this study indicate that the three Brassica species employ very different mechanisms to cope with salinity and, despite its overall sensitivity to salinity, B. oleracea could be recommended as a valuable 'donor' of tissue tolerance genes to confer this trait for marker-assisted breeding programs. © 2016 Scandinavian Plant Physiology Society.

Difference in root K+ retention ability and reduced sensitivity of K+-permeable channels to reactive oxygen species confer differential salt tolerance in three Brassica species.

Science.gov (United States)

Chakraborty, Koushik; Bose, Jayakumar; Shabala, Lana; Shabala, Sergey

2016-08-01

Brassica species are known to possess significant inter and intraspecies variability in salinity stress tolerance, but the cell-specific mechanisms conferring this difference remain elusive. In this work, the role and relative contribution of several key plasma membrane transporters to salinity stress tolerance were evaluated in three Brassica species (B. napus, B. juncea, and B. oleracea) using a range of electrophysiological assays. Initial root growth assay and viability staining revealed that B. napus was most tolerant amongst the three species, followed by B. juncea and B. oleracea At the mechanistic level, this difference was conferred by at least three complementary physiological mechanisms: (i) higher Na(+) extrusion ability from roots resulting from increased expression and activity of plasma membrane SOS1-like Na(+)/H(+) exchangers; (ii) better root K(+) retention ability resulting from stress-inducible activation of H(+)-ATPase and ability to maintain more negative membrane potential under saline conditions; and (iii) reduced sensitivity of B. napus root K(+)-permeable channels to reactive oxygen species (ROS). The last two mechanisms played the dominant role and conferred most of the differential salt sensitivity between species. Brassica napus plants were also more efficient in preventing the stress-induced increase in GORK transcript levels and up-regulation of expression of AKT1, HAK5, and HKT1 transporter genes. Taken together, our data provide the mechanistic explanation for differential salt stress sensitivity amongst these species and shed light on transcriptional and post-translational regulation of key ion transport systems involved in the maintenance of the root plasma membrane potential and cytosolic K/Na ratio as a key attribute for salt tolerance in Brassica species. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Using mineralogy and higher-level taxonomy as indicators of species sensitivity to pH: A case-study of Puget Sound

Directory of Open Access Journals (Sweden)

Shallin Busch

2017-09-01

Full Text Available Information on ecosystem sensitivity to global change can help guide management decisions. Here, we characterize the sensitivity of the Puget Sound ecosystem to ocean acidification by estimating, at a number of taxonomic levels, the direct sensitivity of its species. We compare sensitivity estimates based on species mineralogy and on published literature from laboratory experiments and field studies. We generated information on the former by building a database of species in Puget Sound with mineralogy estimates for all CaCO3-forming species. For the latter, we relied on a recently developed database and meta-analysis on temperate species responses to increased CO2. In general, species sensitivity estimates based on the published literature suggest that calcifying species are more sensitive to increased CO2 than non-calcifying species. However, this generalization is incomplete, as non-calcifying species also show direct sensitivity to high CO2 conditions. We did not find a strong link between mineral solubility and the sensitivity of species survival to changes in carbonate chemistry, suggesting that, at coarse scales, mineralogy plays a lesser role to other physiological sensitivities. Summarizing species sensitivity at the family level resulted in higher sensitivity scalar scores than at the class level, suggesting that grouping results at the class level may overestimate species sensitivity. This result raises caution about the use of broad generalizations on species response to ocean acidification, particularly when developing summary information for specific locations. While we have much to learn about species response to ocean acidification and how to generalize ecosystem response, this study on Puget Sound suggests that detailed information on species performance under elevated carbon dioxide conditions, summarized at the lowest taxonomic level possible, is more valuable than information on species mineralogy.

Effect factors for marine eutrophication in LCIA based on species sensitivity to hypoxia

DEFF Research Database (Denmark)

Cosme, Nuno Miguel Dias; Hauschild, Michael Zwicky

2016-01-01

-observed-effect-concentrations (LOEC), were compiled from literature for 91 demersal species of fish, crustaceans, molluscs, echinoderms, annelids, and cnidarians, and converted to temperature-specific benthic (100 m depth) LOEC values. Species distribution and LOEC values were combined using a species sensitivity distribution (SSD...

From species sensitivity to hypoxia to effect factors modelling in life cycle impact assessment (LCIA)

DEFF Research Database (Denmark)

Cosme, Nuno Miguel Dias; Hauschild, Michael Zwicky

’s sensitivity in five climate zone (polar, subpolar, temperate, subtropical, tropical). Species Sensitivity Distribution (SSD) curves combining DO concentrations and Potentially Affected Fractions (PAF) of species were plotted to estimate hazard concentrations (HC50LOEL) per climate zone, and Effect Factors (EF...

Species-specific sensitivity to selenium-induced impairment of cortisol secretion in adrenocortical cells of rainbow trout (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis)

International Nuclear Information System (INIS)

Miller, L.L.; Hontela, A.

2011-01-01

Species differences in physiological and biochemical attributes exist even among closely related species and may underlie species-specific sensitivity to toxicants. Rainbow trout (RT) are more sensitive than brook trout (BT) to the teratogenic effects of selenium (Se), but it is not known whether all tissues exhibit this pattern of vulnerability. In this study, primary cultures of RT and BT adrenocortical cells were exposed to selenite (Na 2 SO 3 ) and selenomethionine (Se-Met) to compare cell viability and ACTH-stimulated cortisol secretion in the two fish species. Cortisol, the primary stress hormone in fish, facilitates maintenance of homeostasis when fish are exposed to stressors, including toxicants. Cell viability was not affected by Se, but selenite impaired cortisol secretion, while Se-Met did not (RT and BT EC 50 > 2000 mg/L). RT cells were more sensitive (EC 50 = 8.7 mg/L) to selenite than BT cells (EC 50 = 90.4 mg/L). To identify the targets where Se disrupts cortisol synthesis, selenite-impaired RT and BT cells were stimulated with ACTH, dbcAMP, OH-cholesterol, and pregnenolone. Selenite acted at different steps in the cortisol biosynthesis pathway in RT and BT cells, confirming a species-specific toxicity mechanism. To test the hypothesis that oxidative stress mediates Se-induced toxicity, selenite-impaired RT cells were exposed to NAC, BSO and antioxidants (DETCA, ATA, Vit A, and Vit E). Inhibition of SOD by DETCA enhanced selenite-induced cortisol impairment, indicating that oxidative stress plays a role in Se toxicity; however, modifying GSH content of the cells did not have an effect. The results of this study, with two closely related salmonids, provided additional evidence for species-specific differences in sensitivity to Se which should be considered when setting thresholds and water quality guidelines. - Research Highlights: → We investigated species-specific sensitivity to Se in trout adrenocortical cells. → Selenite, not Se-Met, disrupts

Assessing the impact of revegetation and weed control on urban sensitive bird species.

Science.gov (United States)

Archibald, Carla L; McKinney, Matthew; Mustin, Karen; Shanahan, Danielle F; Possingham, Hugh P

2017-06-01

Nature in cities is concentrated in urban green spaces, which are key areas for urban biodiversity and also important areas to connect people with nature. To conserve urban biodiversity within these natural refugia, habitat restoration such as weed control and revegetation is often implemented. These actions are expected to benefit biodiversity, although species known to be affected by urbanization may not be interacting with restoration in the ways we anticipate. In this study, we use a case study to explore how urban restoration activities impact different bird species. Birds were grouped into urban sensitivity categories and species abundance, and richness was then calculated using a hierarchical species community model for individual species responses, with "urban class" used as the hierarchical parameter. We highlight variable responses of birds to revegetation and weed control based on their level of urban sensitivity. Revegetation of open grassy areas delivers significant bird conservation outcomes, but the effects of weed control are neutral or in some cases negative. Specifically, the species most reliant on remnant vegetation in cities seem to remain stable or decline in abundance in areas with weed control, which we suspect is the result of a simplification of the understorey. The literature reports mixed benefits of weed control between taxa and between locations. We recommend, in our case study site, that weed control be implemented in concert with replanting of native vegetation to provide the understory structure preferred by urban sensitive birds. Understanding the impacts of revegetation and weed control on different bird species is important information for practitioners to make restoration decisions about the allocation of funds for conservation action. This new knowledge can be used both for threatened species and invasive species management.

Sensitivity analyses of woody species exposed to air pollution based on ecophysiological measurements.

Science.gov (United States)

Wen, Dazhi; Kuang, Yuanwen; Zhou, Guoyi

2004-01-01

Air pollution has been of a major problem in the Pearl River Delta of south China, particularly during the last two decades. Emissions of air pollutants from industries have already led to damages in natural communities and environments in a wide range of the Delta area. Leaf parameters such as chlorophyll fluorescence, leaf area (LA), dry weight (DW) and leaf mass per area (LMA) had once been used as specific indexes of environmental stress. This study aims to determine in situ if the daily variation of chlorophyll fluorescence and other ecophysiological parameters in five seedlings of three woody species, Ilex rotunda, Ficus microcarpa and Machilus chinensis, could be used alone or in combination with other measurements for sensitivity indexes to make diagnoses under air pollution stress and, hence, to choose the correct tree species for urban afforestation in the Delta area. Five seedlings of each species were transplanted in pot containers after their acclimation under shadowing conditions. Chlorophyll fluorescence measurements were made in situ by a portable fluorometer (OS-30, Opti-sciences, U.S.A). Ten random samples of leaves were picked from each species for LA measurements by area-meter (CI-203, CID, Inc., U.S.A). DW was determined after the leaf samples were dried to a constant weight at 65 degrees C. LMA was calculated as the ratio of DW/LA. Leaf N content was analyzed according to the Kjeldhal method, and the extraction of pigments was carried out according Lin et al. The daily mean Fv/Fm (Fv is the variable fluorescence and Fm is the maximum fluorescence) analysis showed that Ilex rotunda and Ficus microcarpa were more highly resistant to pollution stress, followed by Machilus chinensis, implying that the efficiency of photosystem II in I. rotunda was less affected by air pollutants than the other two species. Little difference in daily change of Fv/Fm in I. rotunda between the polluted and the clean site was also observed. However, a relatively large

Assessing contaminant sensitivity of endangered and threatened aquatic species: Part III. Effluent toxicity tests

Science.gov (United States)

Dwyer, F.J.; Hardesty, D.K.; Henke, C.E.; Ingersoll, C.G.; Whites, D.W.; Augspurger, T.; Canfield, T.J.; Mount, D.R.; Mayer, F.L.

2005-01-01

Toxicity tests using standard effluent test procedures described by the U.S. Environmental Protection Agency were conducted with Ceriodaphnia dubia, fathead minnows (Pimephales promelas), and seven threatened and endangered (listed) fish species from four families: (1) Acipenseridae: shortnose sturgeon (Acipenser brevirostrum); (2) Catostomidae; razorback sucker (Xyrauchen texanus); (3) Cyprinidae: bonytail chub (Gila elegans), Cape Fear shiner (Notropis mekistocholas) Colorado pikeminnow (Ptychocheilus lucius), and spotfin chub (Cyprinella monacha); and (4) Poecillidae: Gila topminnow (Poeciliopsis occidentalis). We conducted 7-day survival and growth studies with embryo-larval fathead minnows and analogous exposures using the listed species. Survival and reproduction were also determined with C. dubia. Tests were conducted with carbaryl, ammonia-or a simulated effluent complex mixture of carbaryl, copper, 4-nonylphenol, pentachlorophenol and permethrin at equitoxic proportions. In addition, Cape Fear shiners and spotfin chub were tested using diazinon, copper, and chlorine. Toxicity tests were also conducted with field-collected effluents from domestic or industrial facilities. Bonytail chub and razorback suckers were tested with effluents collected in Arizona whereas effluent samples collected from North Carolina were tested with Cape Fear shiner, spotfin chub, and shortnose sturgeon. The fathead minnow 7-day effluent test was often a reliable estimator of toxic effects to the listed fishes. However, in 21 % of the tests, a listed species was more sensitive than fathead minnows. More sensitive species results varied by test so that usually no species was always more or less sensitive than fathead minnows. Only the Gila topminnow was consistently less sensitive than the fathead minnow. Listed fish species were protected 96% of the time when results for both fathead minnows and C. dubia were considered, thus reinforcing the value of standard whole

The scotopic visual sensitivity of four species of trout: A comparative study

Science.gov (United States)

Russel B. Rader; Timberley Belish; Michael K. Young; John Rothlisberger

2007-01-01

We compared the maximum scotopic visual sensitivity of 4 species of trout from twilight (mesotopic) to fully dark-adapted vision. Scotopic vision is the minimum number of photons to which a fully dark-adapted animal will show a behavioral response. A comparison of visual sensitivity under controlled laboratory conditions showed that brown trout (Salmo trutta...

Environmentally Sensitive Areas Surveys Program threatened and endangered species survey: Progress report. Environmental Restoration Program

Energy Technology Data Exchange (ETDEWEB)

King, A.L.; Awl, D.J.; Gabrielsen, C.A.

1994-09-01

The Endangered Species Act (originally passed in 1973) is a Federal statute that protects both animal and plant species. The Endangered Species Act identifies species which are, without careful management, in danger of becoming extinct and species that are considered threatened. Along with the designation of threatened or endangered, the Endangered Species Act provides for the identification of appropriate habitat for these species. Since 1993, the United States Department of Energy`s (DOE) Environmental Restoration (ER) Program has supported a program to survey the Oak Ridge Reservation (ORR) for threatened and endangered species. The Environmentally Sensitive Areas Surveys Program initiated vascular plant surveys during fiscal year 1993 and vertebrate animal surveys during fiscal year 1994 to determine the baseline condition of threatened and endangered species on the ORR at the present time. Data collected during these surveys are currently aiding Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Remedial Investigations on the ORR. They also provide data for ER and Waste Management decision documents, ensure that decisions have technical and legal defensibility, provide a baseline for ensuring compliance with principal legal requirements and will increase public confidence in DOE`s adherence to all related environmental resources rules, laws, regulations, and instructions. This report discusses the progress to date of the threatened and endangered species surveys of the ORR.

Sensitive and ultra-fast species detection using pulsed cavity ringdown spectroscopy

KAUST Repository

Alquaity, Awad

2015-01-01

Pulsed cavity ringdown spectroscopy (CRDS) is used to develop a novel, ultra-fast, high-sensitivity diagnostic for measuring species concentrations in shock tube experiments. The diagnostic is demonstrated by monitoring trace concentrations of ethylene in the mid-IR region near 949.47 cm-1. Each ringdown measurement is completed in less than 1 μs and the time period between successive pulses is 10 μs. The high sensitivity diagnostic has a noise-equivalent detection limit of 1.08 x 10-5 cm-1 which enables detection of 15 ppm ethylene at fuel pyrolysis conditions (1845 K and 2 bar) and 294 ppb ethylene under ambient conditions (297 K and 1 bar). To our knowledge, this is the first successful application of the cavity ringdown method to the measurement of species time-histories in a shock tube. © 2015 OSA.

Do predictions from Species Sensitivity Distributions match with field data?

International Nuclear Information System (INIS)

Smetanová, S.; Bláha, L.; Liess, M.; Schäfer, R.B.; Beketov, M.A.

2014-01-01

Species Sensitivity Distribution (SSD) is a statistical model that can be used to predict effects of contaminants on biological communities, but only few comparisons of this model with field studies have been conducted so far. In the present study we used measured pesticides concentrations from streams in Germany, France, and Finland, and we used SSD to calculate msPAF (multiple substance potentially affected fraction) values based on maximum toxic stress at localities. We compared these SSD-based predictions with the actual effects on stream invertebrates quantified by the SPEAR pesticides bioindicator. The results show that the msPAFs correlated well with the bioindicator, however, the generally accepted SSD threshold msPAF of 0.05 (5% of species are predicted to be affected) severely underestimated the observed effects (msPAF values causing significant effects are 2–1000-times lower). These results demonstrate that validation with field data is required to define the appropriate thresholds for SSD predictions. - Highlights: • We validated the statistical model Species Sensitivity Distribution with field data. • Good correlation was found between the model predictions and observed effects. • But, the generally accepted threshold msPAF 0.05 severely underestimated the effects. - Comparison of the SSD-based prediction with the field data evaluated with the SPEAR pesticides index shows that SSD threshold msPAF of 0.05 severely underestimates the effects observed in the field

Setting water quality criteria in China: approaches for developing species sensitivity distributions for metals and metalloids.

Science.gov (United States)

Liu, Yuedan; Wu, Fengchang; Mu, Yunsong; Feng, Chenglian; Fang, Yixiang; Chen, Lulu; Giesy, John P

2014-01-01

Both nonparametric and parametric approaches were used to construct SSDs for use in ecological risk assessments. Based on toxicity to representative aquatic species and typical water contaminants of metals and metalloids in China, nonparametric methods based on the bootstrap were statistically superior to the parametric curve-fitting approaches. Knowing what the SSDs for each targeted species are might help in selecting efficient indicator species to use for water quality monitoring. The species evaluated herein showed sensitivity variations to different chemical treatments that were used in constructing the SSDs. For example, D. magna was more sensitive than most species to most chemical treatments, whereas D. rerio was sensitive to Hg and Pb but was tolerant to Zn. HC5 values, derived for the pollutants in this study for protecting Chinese species, differed from those published by the USEPA. Such differences may result from differences in geographical conditions and biota between China and the United States. Thus, the degree of protection desired for aquatic organisms should be formulated to fit local conditions. For approach selection, we recommend all approaches be considered and the most suitable approaches chosen. The selection should be based on the practical information needs of the researcher (viz., species composition, species sensitivity, and geological characteristics of aquatic habitats), since risk assessments usually are focused on certain substances, species, or monitoring sites. We used Tai Lake as a typical freshwater lake in China to assess the risk of metals and metalloids to the aquatic species. We calculated hazard quotients for the metals and metalloids that were found in the water of this lake. Results indicated the decreasing ecological risk of these contaminants in the following order: Hg metalloids to aquatic species. Based on the MEC and HC5 derived from SSDs by nonparametric and parametric approaches together, the risk levels of metals

Sensitivity to zinc of Mediterranean woody species important for restoration.

Science.gov (United States)

Disante, Karen B; Fuentes, David; Cortina, Jordi

2010-04-15

Heavy metals have increased in natural woodlands and shrublands over the last several decades as a consequence of anthropogenic activities. However, our knowledge of the effects of these elements on woody species is scarce. In this study, we examined the responses of six Mediterranean woody species to increasing levels of zinc in hydroponic culture and discussed the possible implications for the restoration of contaminated sites. The species used, Pinus pinea L., Pinus pinaster Ait., Pinus halepensis Mill., Tetraclinis articulata (Vahl) Mast., Rhamnus alaternus L. and Quercus suber L. represent a climatic gradient from dry sub-humid to semi-arid conditions. Zinc concentrations in shoots ranged from 53 microg g(-1) in Q. suber to 382 microg g(-1) in T. articulata and were well below the levels found in roots. Zinc inhibited root elongation and root biomass and changed the root length distribution per diameter class, but the magnitude of the effects was species-specific. Only P. halepensis and Q. suber showed toxicity symptoms in aboveground parts. Species more characteristic from xeric environments (T. articulata, R. alaternus and P. halepensis) were more sensitive to zinc than species from mesic environments (Q. suber, P. pinaster and P. pinea). According to the Zn responses and bioaccumulation, Q. suber P. pinea and P. halepensis are the best candidates for field trials to test the value of woody species to restore contaminated sites. None of the species tested seemed suitable for phytoremediation. Copyright 2010 Elsevier B.V. All rights reserved.

Alterations in the energy budget of Arctic benthic species exposed to oil-related compounds

Energy Technology Data Exchange (ETDEWEB)

Olsen, Gro Harlaug [Akvaplan-niva, Polar Environmental Center, N-9296 Tromso (Norway) and Norwegian College of Fishery Science, University of Tromso, N-9037 Tromso (Norway)]. E-mail: gho@akvaplan.niva.noph; Sva, Eirin [Akvaplan-niva, Polar Environmental Center, N-9296 Tromso (Norway); Carroll, JoLynn [Akvaplan-niva, Polar Environmental Center, N-9296 Tromso (Norway); Camus, Lionel [Akvaplan-niva, Polar Environmental Center, N-9296 Tromso (Norway); De Coen, Wim [Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp (UA), Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Smolders, Roel [Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp (UA), Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Environmental Toxicology, VITO, Boeretang 200, B-2400 Mol (Belgium); Overaas, Helene [Norwegian Institute for Water Research (NIVA), CIENS, Gaustadalleen, N-0316 Oslo (Norway); Multiconsult AS, Hoffsveien 1, N-0275 Oslo (Norway); Hylland, Ketil [Norwegian Institute for Water Research (NIVA), CIENS, Gaustadalleen, N-0316 Oslo (Norway); Department of Biology, University of Oslo, P.O. Box 1066, Blindern, N-0316 Oslo (Norway)

2007-06-15

We studied cellular energy allocation (CEA) in three Arctic benthic species (Gammarus setosus (Amphipoda), Onisimus litoralis (Amphipoda), and Liocyma fluctuosa (Bivalvia)) exposed to oil-related compounds. The CEA biomarker measures the energy budget of organisms by biochemically assessing changes in energy available (carbohydrates, protein and lipid content) and the integrated energy consumption (electron transport system activity (ETS) as the cellular aspect of respiration). Energy budget was measured in organisms subjected to water-accommodated fraction (WAF) of crude oil and drill cuttings (DC) to evaluate whether these compounds affect the energy metabolism of the test species. We observed significantly lower CEA values and higher ETS activity in G. setosus subjected to WAF treatment compared to controls (p {<=} 0.03). Higher CEA value and lower cellular respiration were observed in O. litoralis exposed to DC compared to controls (p = 0.02). No difference in the energy budget of L. fluctuosa was observed between the treatments (p {>=} 0.19). Different responses to oil-related compounds between the three test species are likely the result of differences in feeding and burrowing behavior and species-specific sensitivity to petroleum-related compounds.

Bio indices for 2,4-D sensitivity between two plant species: Azolla pinnata R.Br. and Vernonia cinerea L. with their cellular responses.

Science.gov (United States)

De, Arnab Kumar; Dey, Narottam; Adak, Malay Kumar

2016-07-01

In the present experiment a pteridophytic species Azolla and an angiospermic species Vernonia were evaluated on the basis of cellular reactivity for herbicidal action through ongoing concentrations. Initially, both the species recorded a significant activity of IAA-oxidase as mark of IAA metabolism with herbicidal sensitivity. Still, Vernonia species were more affected on 2,4-D mediated auxin catabolism. The loss of auxin concentrations on the tissues by 2,4-D reaction was also reflected on growth parameters including relative growth rate and chlorophyll biosynthesis. In a dose dependent manner Vernonia plants were more affected with loss of chlorophyll content and decline in relative growth rate. On the other hand, both those parameters were adjusted significantly with 2,4-D accumulation in Azolla . The stability of cellular metabolism was documented by significant down regulation of protein and lipid peroxidation with concomitant moderation to superoxide and hydrogen peroxide accumulation. The later two were more vulnerable to damage in the Vernonia plant with profuse accumulation of protein and lipid peroxidation products. Similarly, tissue specific reaction to superoxide and hydrogen peroxide accumulation were distinctly demarcated in two species significantly. As a whole, the cellular responses and metabolite distribution to 2,4-D sensitization are the features to describe bio-indices for aquatic fern species Azolla with comparison to angiospermic species Vernonia .

Improved Sensitivity Relations in State Constrained Optimal Control

International Nuclear Information System (INIS)

Bettiol, Piernicola; Frankowska, Hélène; Vinter, Richard B.

2015-01-01

Sensitivity relations in optimal control provide an interpretation of the costate trajectory and the Hamiltonian, evaluated along an optimal trajectory, in terms of gradients of the value function. While sensitivity relations are a straightforward consequence of standard transversality conditions for state constraint free optimal control problems formulated in terms of control-dependent differential equations with smooth data, their verification for problems with either pathwise state constraints, nonsmooth data, or for problems where the dynamic constraint takes the form of a differential inclusion, requires careful analysis. In this paper we establish validity of both ‘full’ and ‘partial’ sensitivity relations for an adjoint state of the maximum principle, for optimal control problems with pathwise state constraints, where the underlying control system is described by a differential inclusion. The partial sensitivity relation interprets the costate in terms of partial Clarke subgradients of the value function with respect to the state variable, while the full sensitivity relation interprets the couple, comprising the costate and Hamiltonian, as the Clarke subgradient of the value function with respect to both time and state variables. These relations are distinct because, for nonsmooth data, the partial Clarke subdifferential does not coincide with the projection of the (full) Clarke subdifferential on the relevant coordinate space. We show for the first time (even for problems without state constraints) that a costate trajectory can be chosen to satisfy the partial and full sensitivity relations simultaneously. The partial sensitivity relation in this paper is new for state constraint problems, while the full sensitivity relation improves on earlier results in the literature (for optimal control problems formulated in terms of Lipschitz continuous multifunctions), because a less restrictive inward pointing hypothesis is invoked in the proof, and because

Comparative analysis of diosgenin in Dioscorea species and related medicinal plants by UPLC-DAD-MS.

Science.gov (United States)

Yi, Tao; Fan, Lan-Lan; Chen, Hong-Li; Zhu, Guo-Yuan; Suen, Hau-Man; Tang, Yi-Na; Zhu, Lin; Chu, Chu; Zhao, Zhong-Zhen; Chen, Hu-Biao

2014-08-09

Dioscorea is a genus of flowering plants, and some Dioscorea species are known and used as a source for the steroidal sapogenin diosgenin. To screen potential resource from Dioscorea species and related medicinal plants for diosgenin extraction, a rapid method to compare the contents of diosgenin in various plants is crucial. An ultra-performance liquid chromatography (UPLC) coupled with diode array detection (DAD) and electrospray ionization mass spectrometry (ESI-MS) method was developed for identification and determination of diosgenin in various plants. A comprehensive validation of the developed method was conducted. Twenty-four batches of plant samples from four Dioscorea species, one Smilax species and two Heterosmilax species were analyzed by using the developed method.The present method presented good sensitivity, precision and accuracy. Diosgenin was found in three Dioscorea species and one Heterosmilax species, namely D. zingiberensis, D. septemloba, D. collettii and H. yunnanensis. The method is suitable for the screening of diosgenin resources from plants. D. zingiberensis is an important resource for diosgenin harvesting.

Development of aquatic life criteria for triclosan and comparison of the sensitivity between native and non-native species.

Science.gov (United States)

Wang, Xiao-Nan; Liu, Zheng-Tao; Yan, Zhen-Guang; Zhang, Cong; Wang, Wei-Li; Zhou, Jun-Li; Pei, Shu-Wei

2013-09-15

Triclosan (TCS) is an antimicrobial agent which is used as a broad-spectrum bacteriostatic and found in personal care products, and due to this it is widely spread in the aquatic environment. However, there is no paper dealing with the aquatic life criteria of TCS, mainly result from the shortage of toxicity data of different taxonomic levels. In the present study, toxicity data were obtained from 9 acute toxicity tests and 3 chronic toxicity tests using 9 Chinese native aquatic species from different taxonomic levels, and the aquatic life criteria was derived using 3 methods. Furthermore, differences of species sensitivity distributions (SSD) between native and non-native species were compared. Among the tested species, demersal fish Misgurnus anguillicaudatus was the most sensitive species, and the fishes were more sensitive than the aquatic invertebrates of Annelid and insect, and the insect was the least sensitive species. The comparison showed that there was no significant difference between SSDs constructed from native and non-native taxa. Finally, a criterion maximum concentration of 0.009 mg/L and a criterion continuous concentration of 0.002 mg/L were developed based on different taxa, according to the U.S. Environmental Protection Agency guidelines. Copyright © 2013 Elsevier B.V. All rights reserved.

Analysis of Sensitivity and Uncertainty in an Individual-Based Model of a Threatened Wildlife Species

Science.gov (United States)

We present a multi-faceted sensitivity analysis of a spatially explicit, individual-based model (IBM) (HexSim) of a threatened species, the Northern Spotted Owl (Strix occidentalis caurina) on a national forest in Washington, USA. Few sensitivity analyses have been conducted on ...

Characterization of Sensitive Species and Habitats Affected by the Operation of USACE Water Resource Development Projects

National Research Council Canada - National Science Library

Kasul, Richard

2000-01-01

...) work unit titled "Reservoir Operations - Impacts on Target Species." Current knowledge regarding the occurrence of sensitive species that have been identified as a management concern in the operation of Corps projects is reviewed...

The relative sensitivity of freshwater species to antimony(III): Implications for water quality guidelines and ecological risk assessments.

Science.gov (United States)

Obiakor, Maximilian Obinna; Tighe, Matthew; Wang, Zhen; Ezeonyejiaku, Chigozie Damian; Pereg, Lily; Wilson, Susan C

2017-11-01

Antimony (Sb) is a pollutant in many jurisdictions, yet its threat to aquatic biota is unclear. Water quality guidelines (WQGs) for Sb are not well established and large uncertainty factors are commonly applied in derivation. We constructed freshwater species sensitivity distributions (SSDs) for Sb(III) using available acute toxicity data sourced from temperate and tropical regional studies. A tiered ecological risk assessment (ERA) approach using risk quotients (RQs) was applied for characterisation of risks presented by Sb(III) concentrations measured in the freshwater environment. Multiple parametric models were fitted for each SSD, with the optimal model used to derive the 5% hazardous concentration (HC5), defined as protective of 95% of species, and the corresponding predicted no effect concentration (PNEC). The HC5 values for whole and temperate SSDs were estimated at 781 and 976 μg L -1 Sb(III), respectively, while the PNECs for both datasets were 156 and 195 μg L -1 Sb(III), respectively. Due to limited tropical data, a temperate-to-tropic extrapolation factor of 10 was used to estimate an interim PNEC for tropical regions of 20 μg L -1 Sb(III). Based on published freshwater Sb(III) concentration values across a range of locations, potential ecological risks posed by Sb(III) in some freshwater systems studied would be classified as medium to high risk, but the majority of locations sampled would fall into the low ecological risk category. Our results facilitate the understanding of toxic effects of Sb(III) to freshwater species but also demonstrate that data for Sb ERA are extremely limited.

The functional highly sensitive brain: a review of the brain circuits underlying sensory processing sensitivity and seemingly related disorders.

Science.gov (United States)

Acevedo, Bianca; Aron, Elaine; Pospos, Sarah; Jessen, Dana

2018-04-19

During the past decade, research on the biological basis of sensory processing sensitivity (SPS)-a genetically based trait associated with greater sensitivity and responsivity to environmental and social stimuli-has burgeoned. As researchers try to characterize this trait, it is still unclear how SPS is distinct from seemingly related clinical disorders that have overlapping symptoms, such as sensitivity to the environment and hyper-responsiveness to incoming stimuli. Thus, in this review, we compare the neural regions implicated in SPS with those found in fMRI studies of-Autism Spectrum Disorder (ASD), Schizophrenia (SZ) and Post-Traumatic Stress Disorder (PTSD) to elucidate the neural markers and cardinal features of SPS versus these seemingly related clinical disorders. We propose that SPS is a stable trait that is characterized by greater empathy, awareness, responsivity and depth of processing to salient stimuli. We conclude that SPS is distinct from ASD, SZ and PTSD in that in response to social and emotional stimuli, SPS differentially engages brain regions involved in reward processing, memory, physiological homeostasis, self-other processing, empathy and awareness. We suggest that this serves species survival via deep integration and memory for environmental and social information that may subserve well-being and cooperation.This article is part of the theme issue 'Diverse perspectives on diversity: multi-disciplinary approaches to taxonomies of individual differences'. © 2018 The Authors.

Uptake and internalisation of copper by three marine microalgae: comparison of copper-sensitive and copper-tolerant species.

Science.gov (United States)

Levy, Jacqueline L; Angel, Brad M; Stauber, Jennifer L; Poon, Wing L; Simpson, Stuart L; Cheng, Shuk Han; Jolley, Dianne F

2008-08-29

Although it has been well established that different species of marine algae have different sensitivities to metals, our understanding of the physiological and biochemical basis for these differences is limited. This study investigated copper adsorption and internalisation in three algal species with differing sensitivities to copper. The diatom Phaeodactylum tricornutum was particularly sensitive to copper, with a 72-h IC50 (concentration of copper to inhibit growth rate by 50%) of 8.0 microg Cu L(-1), compared to the green algae Tetraselmis sp. (72-h IC50 47 microg Cu L(-1)) and Dunaliella tertiolecta (72-h IC50 530 microg Cu L(-1)). At these IC50 concentrations, Tetraselmis sp. had much higher intracellular copper (1.97+/-0.01 x 10(-13)g Cu cell(-1)) than P. tricornutum (0.23+/-0.19 x 10(-13)g Cu cell(-1)) and D. tertiolecta (0.59+/-0.05 x 10(-13)g Cu cell(-1)), suggesting that Tetraselmis sp. effectively detoxifies copper within the cell. By contrast, at the same external copper concentration (50 microg L(-1)), D. tertiolecta appears to better exclude copper than Tetraselmis sp. by having a slower copper internalisation rate and lower internal copper concentrations at equivalent extracellular concentrations. The results suggest that the use of internal copper concentrations and net uptake rates alone cannot explain differences in species-sensitivity for different algal species. Model prediction of copper toxicity to marine biota and understanding fundamental differences in species-sensitivity will require, not just an understanding of water quality parameters and copper-cell binding, but also further knowledge of cellular detoxification mechanisms.

Separating sensitivity from exposure in assessing extinction risk from climate change.

Science.gov (United States)

Dickinson, Maria G; Orme, C David L; Suttle, K Blake; Mace, Georgina M

2014-11-04

Predictive frameworks of climate change extinction risk generally focus on the magnitude of climate change a species is expected to experience and the potential for that species to track suitable climate. A species' risk of extinction from climate change will depend, in part, on the magnitude of climate change the species experiences, its exposure. However, exposure is only one component of risk. A species' risk of extinction will also depend on its intrinsic ability to tolerate changing climate, its sensitivity. We examine exposure and sensitivity individually for two example taxa, terrestrial amphibians and mammals. We examine how these factors are related among species and across regions and how explicit consideration of each component of risk may affect predictions of climate change impacts. We find that species' sensitivities to climate change are not congruent with their exposures. Many highly sensitive species face low exposure to climate change and many highly exposed species are relatively insensitive. Separating sensitivity from exposure reveals patterns in the causes and drivers of species' extinction risk that may not be evident solely from predictions of climate change. Our findings emphasise the importance of explicitly including sensitivity and exposure to climate change in assessments of species' extinction risk.

Relative sensitivity of an amphipod Hyalella azteca, a midge Chironomus dilutus, and a unionid mussel Lampsilis siliquoidea to a toxic sediment

Science.gov (United States)

Ingersoll, Christopher G.; Kunz, James L.; Hughes, Jamie P.; Wang, Ning; Ireland, D. Scott; Mount, David R.; Hockett, J. Russell; Valenti, Ted W

2015-01-01

The objective of the present study was to evaluate the relative sensitivity of test organisms in exposures to dilutions of a highly toxic sediment contaminated with metals and organic compounds. One dilution series was prepared using control sand (low total organic carbon [TOC; TOC [∼10% TOC, higher binding capacity for contaminants]). Test organisms included an amphipod (Hyalella azteca; 10-d and 28-d exposures), a midge (Chironomus dilutus; 20-d and 48-d exposures started with <1-h-old larvae, and 13-d and 48-d exposures started with 7-d-old larvae), and a unionid mussel (Lampsilis siliquoidea; 28-d exposures). Relative species sensitivity depended on the toxicity endpoint and the diluent. All 3 species were more sensitive in sand dilutions than in West Bearskin Lake sediment dilutions. The <1-h-old C. dilutus were more sensitive than 7-d-old C. dilutus, but replicate variability was high in exposures started with the younger midge larvae. Larval biomass and adult emergence endpoints of C. dilutus exhibited a similar sensitivity. Survival, weight, and biomass of H. azteca were more sensitive endpoints in 28-d exposures than in 10-d exposures. Weight and biomass of L. siliquoidea were sensitive endpoints in both sand and West Bearskin Lake sediment dilutions. Metals, ammonia, oil, and other organic contaminants may have contributed to the observed toxicity.

Comparative sensitivity of aquatic invertebrate and vertebrate species to wastewater from an operational coal mine in central Queensland, Australia.

Science.gov (United States)

Lanctôt, C; Wilson, S P; Fabbro, L; Leusch, F D L; Melvin, S D

2016-07-01

Coal excavation and refinement processes generate substantial volumes of contaminated effluent that may be detrimental to aquatic ecosystems. As such, understanding the impacts of coal mine water releases on aquatic animals and ecosystems is essential for effectively managing and protecting neighboring environments. Such information will ultimately be applied towards developing ongoing monitoring strategies that are protective of native wildlife. Despite intensive mining operations in Australia, few studies have documented toxicity associated with coal mine wastewater (CMW) on native species. To address existing knowledge gaps, we investigated acute toxicity (48-96h) using eight native invertebrate species and sub-chronic effects (2 week) using three vertebrate species following exposure to wastewater from two dams (CMW1 and CMW2) located at an open-cut coal mine licensed to discharge into the Fitzroy catchment (Queensland, Australia). Wastewater from these sites is characterized by elevated conductivity, pH, sulfates as well as relatively high total and dissolved metal(loid)s (including As, Al, B, Cu, Mn, Ni, Se and Zn). Acute exposures revealed cladocerans (Daphnia carinata) and planarians (Dugesia sp.) to be the most sensitive species, exhibiting significant mortality after 48 and 96h exposure to CMW2, respectively. Neither wastewater was found to elicit acute toxicity in vertebrates, but a range of sub-lethal morphological effects were observed following the sub-chronic exposures. The overall response pattern was characterized by decreased condition factor and hepatosomatic index in the fish Hypseleotris compressa and Pseudomugil signifier, and in Limnodynastes peronii tadpoles. Tadpoles were generally more sensitive compared to the two fish species. Differences in responses were observed amongst CMW1 and CMW2, which likely relates to differences in physico-chemical properties between sites. Our results have identified several candidate vertebrate and

Integrating human and environmental health in antibiotic risk assessment: A critical analysis of protection goals, species sensitivity and antimicrobial resistance.

Science.gov (United States)

Le Page, Gareth; Gunnarsson, Lina; Snape, Jason; Tyler, Charles R

2017-12-01

Antibiotics are vital in the treatment of bacterial infectious diseases but when released into the environment they may impact non-target organisms that perform vital ecosystem services and enhance antimicrobial resistance development with significant consequences for human health. We evaluate whether the current environmental risk assessment regulatory guidance is protective of antibiotic impacts on the environment, protective of antimicrobial resistance, and propose science-based protection goals for antibiotic manufacturing discharges. A review and meta-analysis was conducted of aquatic ecotoxicity data for antibiotics and for minimum selective concentration data derived from clinically relevant bacteria. Relative species sensitivity was investigated applying general linear models, and predicted no effect concentrations were generated for toxicity to aquatic organisms and compared with predicted no effect concentrations for resistance development. Prokaryotes were most sensitive to antibiotics but the range of sensitivities spanned up to several orders of magnitude. We show reliance on one species of (cyano)bacteria and the 'activated sludge respiration inhibition test' is not sufficient to set protection levels for the environment. Individually, neither traditional aquatic predicted no effect concentrations nor predicted no effect concentrations suggested to safeguard for antimicrobial resistance, protect against environmental or human health effects (via antimicrobial resistance development). Including data from clinically relevant bacteria and also more species of environmentally relevant bacteria in the regulatory framework would help in defining safe discharge concentrations for antibiotics for patient use and manufacturing that would protect environmental and human health. It would also support ending unnecessary testing on metazoan species. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Effect factors for marine eutrophication in LCIA based on species sensitivity to hypoxia

DEFF Research Database (Denmark)

Cosme, Nuno Miguel Dias; Hauschild, Michael Zwicky

2016-01-01

Hypoxia is an important environmental stressor to marine species, especially in benthic coastal waters. Increasing anthropogenic emissions of nutrients and organic matter contribute to the depletion of dissolved oxygen (DO). Biotic sensitivity to low levels of DO is determined by the organisms...

Taxonomy of Penicillium citrinum and related species

DEFF Research Database (Denmark)

Houbraken, J.A.M.P.; Frisvad, Jens Christian; Samson, A.F.

2010-01-01

are related to P. citrinum, P. gorlenkoanum is revived, Penicillium hetheringtonii sp. nov. and Penicillium tropicoides sp. nov. are described here as new species, and the combination Penicillium tropicum is proposed. Penicillium hetheringtonii is closely related to P. citrinum and differs in having slightly......Penicillium citrinum and related species have been examined using a combination of partial beta-tubulin, calmodulin and ITS sequence data, extrolite patterns and phenotypic characters. It is concluded that seven species belong to the series Citrina. Penicillium sizovae and Penicillium steckii...... broader stipes, metulae in verticils of four or more and the production of an uncharacterized metabolite, tentatively named PR1-x. Penicillium tropicoides resembles P. tropicum, but differs in the slow maturation of the cleistothecia, slower growth at 30A degrees C and the production of isochromantoxins...

Chemical kinetic functional sensitivity analysis: Elementary sensitivities

International Nuclear Information System (INIS)

Demiralp, M.; Rabitz, H.

1981-01-01

Sensitivity analysis is considered for kinetics problems defined in the space--time domain. This extends an earlier temporal Green's function method to handle calculations of elementary functional sensitivities deltau/sub i//deltaα/sub j/ where u/sub i/ is the ith species concentration and α/sub j/ is the jth system parameter. The system parameters include rate constants, diffusion coefficients, initial conditions, boundary conditions, or any other well-defined variables in the kinetic equations. These parameters are generally considered to be functions of position and/or time. Derivation of the governing equations for the sensitivities and the Green's funciton are presented. The physical interpretation of the Green's function and sensitivities is given along with a discussion of the relation of this work to earlier research

Climate change sensitivity of the African ivory nut palm, Hyphaena petersiana Klotzsch ex Mart. (arecaceae) - a keystone species in SE Africa

DEFF Research Database (Denmark)

Overgaard, Anne Blach; Svenning, J.-C.; Balslev, Henrik

2009-01-01

the climate sensitivity of the key-stone palm species Hyphaene petersiana (African ivory nut palm) in southern Africa. We tested the relative roles of climate vs. non-climatic range-controls and found that climate had a clear effect on the range of H. petersiana and that especially water-related variables......Africa is the most vulnerable continent to future climate change. Profound changes are projected for southwestern Africa with increased drying, notably with delayed onset of the rainy season in September-November, and temperature increases in all seasons. The projected climate changes combined...... species by humans and livestock are likely to exacerbate the negative effect of future climate changes on its populations, especially, given the expected human population increase in Africa....

Taxonomy of Penicillium citrinum and related species

NARCIS (Netherlands)

Houbraken, J.; Frisvad, J.C.; Samson, R.A.

2010-01-01

Penicillium citrinum and related species have been examined using a combination of partial beta-tubulin, calmodulin and ITS sequence data, extrolite patterns and phenotypic characters. It is concluded that seven species belong to the series Citrina. Penicillium sizovae and Penicillium steckii are

The clinical relevance of sensitization to pollen-related fruits and vegetables in unselected pollen-sensitized adults

DEFF Research Database (Denmark)

Osterballe, M.; Hansen, T.K.; Mørtz, Charlotte G

2005-01-01

BACKGROUND: Previous studies have described cross-reactivity between fresh fruits, vegetables and pollen. However, no data demonstrates the clinical relevance of sensitization to pollen-related fruits and vegetables in unselected pollen-sensitized adults with and without symptoms in the pollen...... season. OBJECTIVE: The aim of this study was to estimate the clinical relevance of sensitization to pollen-related fruits and vegetables in unselected pollen-sensitized adults and to examine the diagnostic value of skin-prick test (SPT), histamine release and specific IgE compared with the outcome...... of oral challenge. METHODS: In total, 936 unselected adults (female : male 479 : 457, median age 33.7 years) were examined for pollen sensitization and clinical cross-reactivity with pollen-related fruits and vegetables by questionnaire, SPT, histamine release, specific IgE and oral challenge. RESULTS...

Rapid and sensitive multiplex single-tube nested PCR for the identification of five human Plasmodium species.

Science.gov (United States)

Saito, Takahiro; Kikuchi, Aoi; Kaneko, Akira; Isozumi, Rie; Teramoto, Isao; Kimura, Masatsugu; Hirasawa, Noriyasu; Hiratsuka, Masahiro

2018-06-01

Malaria is caused by five species of Plasmodium in humans. Microscopy is currently used for pathogen detection, requiring considerable training and technical expertise as the parasites are often difficult to differentiate morphologically. Rapid diagnostic tests are as reliable as microscopy and offer faster diagnoses but possess lower detection limits and are incapable of distinguishing among the parasitic species. To improve global health efforts towards malaria control, a rapid, sensitive, species-specific, and economically viable diagnostic method is needed. In this study, we designed a malaria diagnostic method involving a multiplex single-tube nested PCR targeting Plasmodium mitochondrial cytochrome c oxidase III and single-stranded tag hybridization chromatographic printed-array strip. The detection sensitivity was found to be at least 40 times higher than that of agarose gel electrophoresis with ethidium bromide. This system also enables the identification of both single- and mixed-species malaria infections. The assay was validated with 152 Kenyan samples; using nested PCR as the standard, the assay's sensitivity and specificity were 88.7% and 100.0%, respectively. The turnaround time required, from PCR preparation to signal detection, is 90min. Our method should improve the diagnostic speed, treatment efficacy, and control of malaria, in addition to facilitating surveillance within global malaria eradication programs. Copyright © 2018 Elsevier B.V. All rights reserved.

Drought responses of three closely related Caragana species: implication for their vicarious distribution.

Science.gov (United States)

Ma, Fei; Na, Xiaofan; Xu, Tingting

2016-05-01

Drought is a major environmental constraint affecting growth and distribution of plants in the desert region of the Inner Mongolia plateau. Caragana microphylla, C. liouana, and C. korshinskii are phylogenetically close but distribute vicariously in Mongolia plateau. To gain a better understanding of the ecological differentiation between these three species, we examined the leaf gas exchange, growth, water use efficiency, biomass accumulation and allocation by subjecting their seedlings to low and high drought treatments in a glasshouse. Increasing drought stress had a significant effect on many aspects of seedling performance in all species, but the physiology and growth varied with species in response to drought. C. korshinskii exhibited lower sensitivity of photosynthetic rate and growth, lower specific leaf area, higher biomass allocation to roots, higher levels of water use efficiency to drought compared with the other two species. Only minor interspecific differences in growth performances were observed between C. liouana and C. microphylla. These results indicated that faster seedling growth rate and more efficient water use of C. korshinskii should confer increased drought tolerance and facilitate its establishment in more severe drought regions relative to C. liouana and C. microphylla.

Differential sensitivity to natural ultraviolet radiation among phytoplankton species in Arctic lakes (Spitsbergen, Norway)

NARCIS (Netherlands)

Donk, van E.; Faafeng, B.A.; Lange, de H.J.

2001-01-01

Incubation experiments demonstrated a differential sensitivity to natural UV-radiation among the dominant phytoplankton species from three Arctic lakes, situated near Ny-Ålesund, Spitsbergen (79° N). The growth of small chlorophytes, diatoms and picocyanobacteria from two oligotrophic lakes was

Rapid identification of the Asian gypsy moth and its related species based on mitochondrial DNA.

Science.gov (United States)

Wu, Ying; Du, Qiuyang; Qin, Haiwen; Shi, Juan; Wu, Zhiyi; Shao, Weidong

2018-02-01

The gypsy moth- Lymantria dispar (Linnaeus)-is a worldwide forest defoliator and is of two types: the European gypsy moth and the Asian gypsy moth. Because of multiple invasions of the Asian gypsy moth, the North American Plant Protection Organization officially approved Regional Standards for Phytosanitary Measures No. 33. Accordingly, special quarantine measures have been implemented for 30 special focused ports in the epidemic areas of the Asian gypsy moth, including China, which has imposed great inconvenience on export trade. The Asian gypsy moth and its related species (i.e., Lymantria monocha and Lymantria xylina ) intercepted at ports are usually at different life stages, making their identification difficult. Furthermore, Port quarantine requires speedy clearance. As such, it is difficult to identify the Asian gypsy moth and its related species only by their morphological characteristics in a speedy measure. Therefore, this study aimed to use molecular biology technology to rapidly identify the Asian gypsy moth and its related species based on the consistency of mitochondrial DNA in different life stages. We designed 10 pairs of specific primers from different fragments of the Asian gypsy moth and its related species, and their detection sensitivity met the need for rapid identification. In addition, we determined the optimal polymerase chain reaction amplification temperature of the 10 pairs of specific primers, including three pairs of specific primers for the Asian gypsy moth ( L. dispar asiatic ), four pairs of specific primers for the nun moth ( L. monocha ), and three pairs of specific primers for the casuarina moth ( L. xylina ). In conclusion, using our designed primers, direct rapid identification of the Asian gypsy moth and its related species is possible, and this advancement can help improve export trade in China.

Fast and sensitive method for detecting volatile species in liquids

Science.gov (United States)

Trimarco, Daniel B.; Pedersen, Thomas; Hansen, Ole; Chorkendorff, Ib; Vesborg, Peter C. K.

2015-07-01

This paper presents a novel apparatus for extracting volatile species from liquids using a "sniffer-chip." By ultrafast transfer of the volatile species through a perforated and hydrophobic membrane into an inert carrier gas stream, the sniffer-chip is able to transport the species directly to a mass spectrometer through a narrow capillary without the use of differential pumping. This method inherits features from differential electrochemical mass spectrometry (DEMS) and membrane inlet mass spectrometry (MIMS), but brings the best of both worlds, i.e., the fast time-response of a DEMS system and the high sensitivity of a MIMS system. In this paper, the concept of the sniffer-chip is thoroughly explained and it is shown how it can be used to quantify hydrogen and oxygen evolution on a polycrystalline platinum thin film in situ at absolute faradaic currents down to ˜30 nA. To benchmark the capabilities of this method, a CO-stripping experiment is performed on a polycrystalline platinum thin film, illustrating how the sniffer-chip system is capable of making a quantitative in situ measurement of <1 % of a monolayer of surface adsorbed CO being electrochemically stripped off an electrode at a potential scan-rate of 50 mV s-1.

Toxicity of lead (Pb) to freshwater green algae: Development and validation of a bioavailability model and inter-species sensitivity comparison

Energy Technology Data Exchange (ETDEWEB)

De Schamphelaere, K.A.C., E-mail: karel.deschamphelaere@ugent.be; Nys, C., E-mail: chnys.nys@ugent.be; Janssen, C.R., E-mail: colin.janssen@ugent.be

2014-10-15

Highlights: • Chronic toxicity of Pb varied 4-fold among three algae species. • The use of an organic P avoided Pb precipitation in the experiments. • pH and Dissolved Organic Carbon strongly affect Pb toxicity, Ca and Mg do not. • A bioavailability model was developed that accurately predicts toxicity. • Algae may become the most sensitive species to Pb above pH 7.4. - Abstract: Scientifically sound risk assessment and derivation of environmental quality standards for lead (Pb) in the freshwater environment are hampered by insufficient data on chronic toxicity and bioavailability to unicellular green algae. Here, we first performed comparative chronic (72-h) toxicity tests with three algal species in medium at pH 6, containing 4 mg fulvic acid (FA)/L and containing organic phosphorous (P), i.e. glycerol-2-phosphate, instead of PO{sub 4}{sup 3−} to prevent lead-phosphate mineral precipitation. Pseudokirchneriella subcapitata was 4-fold more sensitive to Pb than Chlorella kesslerii, with Chlamydomonas reinhardtii in the middle. The influence of medium physico-chemistry was therefore investigated in detail with P. subcapitata. In synthetic test media, higher concentrations of fulvic acid or lower pH protected against toxicity of (filtered) Pb to P. subcapitata, while effects of increased Ca or Mg on Pb toxicity were less clear. When toxicity was expressed on a free Pb{sup 2+} ion activity basis, a log-linear, 260-fold increase of toxicity was observed between pH 6.0 and 7.6. Effects of fulvic acid were calculated to be much more limited (1.9-fold) and were probably even non-existent (depending on the affinity constant for Pb binding to fulvic acid that was used for calculating speciation). A relatively simple bioavailability model, consisting of a log-linear pH effect on Pb{sup 2+} ion toxicity linked to the geochemical speciation model Visual Minteq (with the default NICA-Donnan description of metal and proton binding to fulvic acid), provided relatively

Toxicity of lead (Pb) to freshwater green algae: Development and validation of a bioavailability model and inter-species sensitivity comparison

International Nuclear Information System (INIS)

De Schamphelaere, K.A.C.; Nys, C.; Janssen, C.R.

2014-01-01

Highlights: • Chronic toxicity of Pb varied 4-fold among three algae species. • The use of an organic P avoided Pb precipitation in the experiments. • pH and Dissolved Organic Carbon strongly affect Pb toxicity, Ca and Mg do not. • A bioavailability model was developed that accurately predicts toxicity. • Algae may become the most sensitive species to Pb above pH 7.4. - Abstract: Scientifically sound risk assessment and derivation of environmental quality standards for lead (Pb) in the freshwater environment are hampered by insufficient data on chronic toxicity and bioavailability to unicellular green algae. Here, we first performed comparative chronic (72-h) toxicity tests with three algal species in medium at pH 6, containing 4 mg fulvic acid (FA)/L and containing organic phosphorous (P), i.e. glycerol-2-phosphate, instead of PO 4 3− to prevent lead-phosphate mineral precipitation. Pseudokirchneriella subcapitata was 4-fold more sensitive to Pb than Chlorella kesslerii, with Chlamydomonas reinhardtii in the middle. The influence of medium physico-chemistry was therefore investigated in detail with P. subcapitata. In synthetic test media, higher concentrations of fulvic acid or lower pH protected against toxicity of (filtered) Pb to P. subcapitata, while effects of increased Ca or Mg on Pb toxicity were less clear. When toxicity was expressed on a free Pb 2+ ion activity basis, a log-linear, 260-fold increase of toxicity was observed between pH 6.0 and 7.6. Effects of fulvic acid were calculated to be much more limited (1.9-fold) and were probably even non-existent (depending on the affinity constant for Pb binding to fulvic acid that was used for calculating speciation). A relatively simple bioavailability model, consisting of a log-linear pH effect on Pb 2+ ion toxicity linked to the geochemical speciation model Visual Minteq (with the default NICA-Donnan description of metal and proton binding to fulvic acid), provided relatively accurate toxicity

Acute and chronic sensitivity to copper of a promising ecotoxicological model species, the annual killifish Nothobranchius furzeri.

Science.gov (United States)

Philippe, Charlotte; Grégoir, Arnout F; Janssens, Lizanne; Pinceel, Tom; De Boeck, Gudrun; Brendonck, Luc

2017-10-01

Nothobranchius furzeri is a promising model for ecotoxicological research due to the species' short life cycle and the production of drought-resistant eggs. Although the species is an emerging vertebrate fish model for several fundamental as well as applied research domains, its potential for ecotoxicological research has not yet been tested. The aim of this study was to characterise the acute and chronic sensitivity of this species to copper as compared to other model organisms. Effects of both acute and chronic copper exposure were tested on survival, life history and physiological traits. We report a 24h-LC 50 of 53.93µg Cu/L, which is situated within the sensitivity range of other model species such as Brook Trout, Fathead Minnow and Rainbow Trout. Moreover, in the full life cycle exposure, we show that an exposure concentration of 10.27µg/L did not cause acute adverse effects (96h), but did cause mortality after prolonged exposure (3-4 weeks). Also chronic, sublethal effects were observed, such as a reduction in growth rate, delayed maturation and postponed reproduction. Based on our results, we define the NOEC at 6.68µg Cu/L, making N. furzeri more sensitive to copper as compared to Brook Trout and Fathead Minnow. We found stimulatory effects on peak fecundity at subinhibitory levels of copper concentrations (hormesis). Finally, we found indications for detoxifying and copper-excreting mechanisms, demonstrating the ability of the fish to cope with this essential metal, even when exposed to stressful amounts. The successful application of current ecotoxicological protocols on N. furzeri and its sensitivity range comparable to that of other model organisms forms the basis to exploit this species in further ecotoxicological practices. Copyright © 2017 Elsevier Inc. All rights reserved.

Confirming the species-sensitivity distribution concept for endosulfan using laboratory, mesocosm, and field data

NARCIS (Netherlands)

Hose, G.C.; Brink, van den P.J.

2004-01-01

In Australia, water-quality trigger values for toxicants are derived using protective concentration values based on species-sensitivity distribution (SSD) curves. SSD curves are generally derived from laboratory data with an emphasis on using local or site-specific data. In this study, Australian

Comparative sensitivity of Selenastrum capricornutum and Lemna minor to sixteen herbicides

Science.gov (United States)

Fairchild, J.F.; Ruessler, D.S.; Haverland, P.S.; Carlson, A.R.

1997-01-01

Aquatic plant toxicity tests are frequently conducted in environmental risk assessments to determine the potential impacts of contaminants on primary producers. An examination of published plant toxicity data demonstrates that wide differences in sensitivity can occur across phylogenetic groups of plants. Yet relatively few studies have been conducted with the specific intent to compare the relative sensitivity of various aquatic plant species to contaminants. We compared the relative sensitivity of the algae Selenestrum capricornutum and the floating vascular plant Lemna minor to 16 herbicides (atrazine, metribuzin, simazine, cyanazine, alachlor, metolachlor, chlorsulfuron, metsulfuron, triallate, EPTC, trifluralin, diquat, paraquat, dicamba, bromoxynil, and 2,4-D). The herbicides studied represented nine chemical classes and several modes of action and were chosen to represent major current uses in the United States. Both plant species were generally sensitive to the triazines (atrazine, metribuzin, simazine, and cyanazine), sulfonureas (metsulfuron and chlorsulfuron), pyridines (diquat and paraquat), dinitroaniline (trifluralin), and acetanilide (alachlor and metolachlor) herbicides. Neither plant species was uniformly more sensitive than the other across the broad range of herbicides tested. Lemna was more sensitive to the sulfonureas (metsulfuron and chlorsulfuron) and the pyridines (diquat and parequat) than Selenastrum. However Selenastrum was more sensitive than Lemna to one of two thiocarbamates (triallate) and one of the triazines (cyanazine). Neither species was sensitive to selective broadleaf herbicides including bromoxynil, EPTC, dicamba, or 2,4-D. Results were not always predictable in spite of obvious differences in herbicide modes of action and plant phylogeny. Major departures in sensitivity of Selenastrum occurred between chemicals within individual classes of the triazine, acetanilide, and thiocarbamate herbicides. Results indicate that neither

Preliminary assessment of terrestrial microalgae isolated from lichens as testing species for environmental monitoring: lichen phycobionts present high sensitivity to environmental micropollutants.

Science.gov (United States)

Domínguez-Morueco, N; Moreno, H; Barreno, E; Catalá, M

2014-01-01

Bioassays constitute a tool for pollution analysis providing a holistic approach and high-quality indication of the toxicity. Microbioassays allow evaluating the toxicity of many samples, implying lower costs and enabling routine monitoring and pollution control. But tests conducted so far are limited to the use of a small number of taxa. Lichens are excellent bioindicators of pollution with great ecological significance. Studies show that the phycobiont is more sensitive to pollutants than the mycobiont. Phycobiont have features such as adaptation to anhydrobiosis and relatively rapid growth in vitro, making them suitable for microbioassays. Our aim is to determine the sensitivity of phycobionts to the pharmaceutical micropollutants carbamazepine and diclofenac as a preliminary step for the development of a toxicity microbioassay based on phycobionts. Optical dispersion and chlorophyll autofluorescence were used as endpoints of toxicity on two algal species showing that suspensions present cyclic and taxon specific patterns of aggregation. Trebouxia TR9 suspensions present a very high grade of aggregation while Asterochloris erici cells do not. Both micropollutants alter optical properties of the suspensions of both species. No significant alteration of chlorophyll autofluorescence by carbamazepine is observed. A. erici chlorophyll autofluorescence is extremely sensitive to diclofenac but the effect is not dependent on the drug concentration or on the time of exposure. Differently, TR9 only shows punctual chlorophyll alterations. Fluctuations in optical dispersion may indicate changes in the population structure of the species, including reproductive strategy. A. erici seems more sensitive to micropollutants, is better characterized and is available from commercial collections. © 2013 Published by Elsevier Inc.

Hearing sensitivity in context: Conservation implications for a highly vocal endangered species

OpenAIRE

Owen, Megan A.; Keating, Jennifer L.; Denes, Samuel K.; Hawk, Kathy; Fiore, Angela; Thatcher, Julie; Becerra, Jennifer; Hall, Suzanne; Swaisgood, Ronald R.

2016-01-01

Hearing sensitivity is a fundamental determinant of a species’ vulnerability to anthropogenic noise, however little is known about the hearing capacities of most conservation dependent species. When audiometric data are integrated with other aspects of species’ acoustic ecology, life history, and characteristic habitat topography and soundscape, predictions can be made regarding probable vulnerability to the negative impacts of different types of anthropogenic noise. Here we used an adaptive ...

Effects of temperature, genetic variation and species competition on the sensitivity of algae populations to the antibiotic enrofloxacin.

Science.gov (United States)

Rico, Andreu; Zhao, Wenkai; Gillissen, Frits; Lürling, Miquel; Van den Brink, Paul J

2018-02-01

Primary producers are amongst the most sensitive organisms to antibiotic pollution in aquatic ecosystems. To date, there is little information on how different environmental conditions may affect their sensitivity to antibiotics. In this study we assessed how temperature, genetic variation and species competition may affect the sensitivity of the cyanobacterium Microcystis aeruginosa and the green-algae Scenedesmus obliquus to the antibiotic enrofloxacin. First, we performed single-species tests to assess the toxicity of enrofloxacin under different temperature conditions (20°C and 30°C) and to assess the sensitivity of different species strains using a standard temperature (20°C). Next, we investigated how enrofloxacin contamination may affect the competition between M. aeruginosa and S. obliquus. A competition experiment was performed following a full factorial design with different competition treatments, defined as density ratios (i.e. initial bio-volume of 25/75%, 10/90% and 1/99% of S. obliquus/M. aeruginosa, respectively), one 100% S. obliquus treatment and one 100% M. aeruginosa treatment, and four different enrofloxacin concentrations (i.e. control, 0.01, 0.05 and 0.10mg/L). Growth inhibition based on cell number, bio-volume, chlorophyll-a concentration as well as photosynthetic activity were used as evaluation endpoints in the single-species tests, while growth inhibition based on measured chlorophyll-a was primarily used in the competition experiment. M. aeruginosa photosynthetic activity was found to be the most sensitive endpoint to enrofloxacin (EC50-72h =0.02mg/L), followed by growth inhibition based on cell number. S. obliquus was found to be slightly more sensitive at 20°C than at 30°C (EC50-72h cell number growth inhibition of 38 and 41mg/L, respectively), whereas an opposite trend was observed for M. aeruginosa (0.047 and 0.037mg/L, respectively). Differences in EC50-72h values between algal strains of the same species were within a factor

Highly sensitive quantitative PCR for the detection and differentiation of Pseudogymnoascus destructans and other Pseudogymnoascus species.

Science.gov (United States)

Shuey, Megan M; Drees, Kevin P; Lindner, Daniel L; Keim, Paul; Foster, Jeffrey T

2014-03-01

White-nose syndrome is a fungal disease that has decimated bat populations across eastern North America. Identification of the etiologic agent, Pseudogymnoascus destructans (formerly Geomyces destructans), in environmental samples is essential to proposed management plans. A major challenge is the presence of closely related species, which are ubiquitous in many soils and cave sediments and often present in high abundance. We present a dual-probe real-time quantitative PCR assay capable of detecting and differentiating P. destructans from closely related fungi in environmental samples from North America. The assay, based on a single nucleotide polymorphism (SNP) specific to P. destructans, is capable of rapid low-level detection from various sampling media, including sediment, fecal samples, wing biopsy specimens, and skin swabs. This method is a highly sensitive, high-throughput method for identifying P. destructans, other Pseudogymnoascus spp., and Geomyces spp. in the environment, providing a fundamental component of research and risk assessment for addressing this disease, as well as other ecological and mycological work on related fungi.

Effect of nitric acid for equal stabilization and sensitivity of different selenium species in electrothermal atomic absorption spectrometry

Energy Technology Data Exchange (ETDEWEB)

Sahin, Feyime [Department of Chemistry, Middle East Technical University, 06531 Ankara (Turkey); Volkan, Muervet [Department of Chemistry, Middle East Technical University, 06531 Ankara (Turkey); Ataman, O. Yavuz [Department of Chemistry, Middle East Technical University, 06531 Ankara (Turkey)]. E-mail: ataman@metu.edu.tr

2005-08-15

Determination of selenium by electrothermal atomic absorption spectrometry (ETAAS) is complicated by the presence of different species of this analyte. The presence of different oxidation states (-II, IV and VI) may result in different sensitivities obtained for each species rendering impossible the use of a single species for calibration. These species also exhibit different behaviours regarding thermal stabilities; the temperature program must be provided to conform to this problem. Chemical modifiers are commonly used for thermal stabilization of selenium species. In this study, experiments were carried out to demonstrate the effect of nitric acid in the presence of chemical modifiers. Nickel and palladium + magnesium were selected as the most commonly used chemical modifiers. Using both aqueous and human serum solutions it has been demonstrated that although chemical modifiers provide thermal stabilization of species so that higher ashing temperatures can be used, equal sensitivities cannot be achieved unless nitric acid is also present. Selenite, selenate, selenomethionine and selenocystine were used in experiments. When equal sensitivities for all these species are achieved, determination of total selenium by ETAAS can be performed by using a single species as the standard; selenite was used in this study. Precision was 5.0% or better using peak height signals. There was no significant difference in detection limits (3s) when Ni or Pd + Mg(NO{sub 3}){sub 2} was used as chemical modifier; 37 and 35 pg of selenium were found to be the detection limits for Ni and Pd + Mg(NO{sub 3}){sub 2} chemical modifiers, respectively. For chemical modifications, either 5 {mu}g of Ni or 0.5 {mu}g of Pd and 5 {mu}g of Mg(NO{sub 3}){sub 2} were used; final solutions contained 2.5% HNO{sub 3}. In serum analyses, 10 {mu}g of Ni was used in presence of 2.5% HNO{sub 3}.

Nucleosome-coupled expression differences in closely-related species

Directory of Open Access Journals (Sweden)

Gebbia Marinella

2011-09-01

Full Text Available Abstract Background Genome-wide nucleosome occupancy is negatively related to the average level of transcription factor motif binding based on studies in yeast and several other model organisms. The degree to which nucleosome-motif interactions relate to phenotypic changes across species is, however, unknown. Results We address this challenge by generating nucleosome positioning and cell cycle expression data for Saccharomyces bayanus and show that differences in nucleosome occupancy reflect cell cycle expression divergence between two yeast species, S. bayanus and S. cerevisiae. Specifically, genes with nucleosome-depleted MBP1 motifs upstream of their coding sequence show periodic expression during the cell cycle, whereas genes with nucleosome-shielded motifs do not. In addition, conserved cell cycle regulatory motifs across these two species are more nucleosome-depleted compared to those that are not conserved, suggesting that the degree of conservation of regulatory sites varies, and is reflected by nucleosome occupancy patterns. Finally, many changes in cell cycle gene expression patterns across species can be correlated to changes in nucleosome occupancy on motifs (rather than to the presence or absence of motifs. Conclusions Our observations suggest that alteration of nucleosome occupancy is a previously uncharacterized feature related to the divergence of cell cycle expression between species.

TRPA1 channels in Drosophila and honey bee ectoparasitic mites share heat sensitivity and temperature-related physiological functions

Directory of Open Access Journals (Sweden)

Guangda Peng

2016-10-01

Full Text Available The transient receptor potential cation channel, subfamily A, member 1 (TRPA1 is conserved between many arthropods, and in some has been shown to function as a chemosensor for noxious compounds. Activation of arthropod TRPA1 channels by temperature fluctuations has been tested in only a few insect species, and all of them were shown to be activated by heat. The recent identification of chemosensitive TRPA1 channels from two honey bee ectoparasitic mite species (VdTRPA1 and TmTRPA1 have provided an opportunity to study the temperature-dependent activation and the temperature-associated physiological functions of TRPA1 channels in non-insect arthropods. We found that both mite TRPA1 channels are heat sensitive and capable of rescuing the temperature-related behavioral defects of a Drosophila melanogaster trpA1 mutant. These results suggest that heat-sensitivity of TRPA1 could be conserved between many arthropods despite its amino acid sequence diversity. Nevertheless, the ankyrin repeats (ARs 6 and 7 are well-conserved between six heat-sensitive arthropod TRPA1 channels and have critical roles for the heat activation of VdTRPA1.

Relation of chironomids with Aeromonas species

Directory of Open Access Journals (Sweden)

Sivan eLaviad

2016-05-01

Full Text Available Chironomids (Diptera: Chironomidae, also known as non-biting midges, are one of the most abundant groups of insects in aquatic habitats. They undergo a complete metamorphosis of four life stages of which three are aquatic (egg, larva, pupa, and the adult emerges into the air. Chironomids serve as a natural reservoir of Aeromonas and Vibrio cholerae species. Here we review existing knowledge about the mutual relations between Aeromonas species and chironomids. Using 454-pyrosequencing of the 16S rRNA gene, we found that the prevalence of Aeromonas species in the insects’ egg masses and larvae was 1.6% and 3.3% of the insects’ endogenous microbiota, respectively. Aeromonas abundance per egg mass remained stable during a six-month period of bacterial monitoring. Different Aeromonas species were isolated and some demonstrated the ability to degrade the insect’s egg masses and to prevent eggs hatching. Chitinase was identified as the enzyme responsible for the egg mass degradation. Different Aeromonas species isolated from chironomids demonstrated the potential to protect their host from toxic metals. Aeromonas is a causative agent of fish infections. Fish are frequently recorded as feeding on chironomids. Thus, fish might be infected with Aeromonas species via chironomid consumption. Aeromonas strains are also responsible for causing gastroenteritis and wound infections in humans. Different virulence genes were identified in Aeromonas species isolated from chironomids. Chironomids may infest drinking water reservoirs, hence be the source of pathogenic Aeromonas strains in drinking water. Chironomids and Aeromonas species have a complicated mutual relationship.

Impact of triphenyltin acetate in microcosms simulating floodplain lakes. II. Comparison of species sensitivity distributions between laboratory and semi-field.

Science.gov (United States)

Roessink, I; Belgers, J D M; Crum, S J H; van den Brink, P J; Brock, T C M

2006-07-01

The study objectives were to shed light on the types of freshwater organism that are sensitive to triphenyltin acetate (TPT) and to compare the laboratory and microcosm sensitivities of the invertebrate community. The responses of a wide array of freshwater taxa (including invertebrates, phytoplankton and macrophytes) from acute laboratory Single Species Tests (SST) were compared with the concentration-response relationships of aquatic populations in two types of freshwater microcosms. Representatives of several taxonomic groups of invertebrates, and several phytoplankton and vascular plant species proved to be sensitive to TPT, illustrating its diverse modes of toxic action. Statistically calculated ecological risk thresholds (HC5 values) based on 96 h laboratory EC50 values for invertebrates were 1.3 microg/l, while these values on the basis of microcosm-Species Sensitivity Distributions (SSD) for invertebrates in sampling weeks 2-8 after TPT treatment ranged from 0.2 to 0.6 microg/l based on nominal peak concentrations. Responses observed in the microcosms did not differ between system types and sampling dates, indicating that ecological threshold levels are not affected by different community structures including taxa sensitive to TPT. The laboratory-derived invertebrate SSD curve was less sensitive than the curves from the microcosms. Possible explanations for the more sensitive field response are delayed effects and/or additional chronic exposure via the food chain in the microcosms.

Model-Based Evaluation of Urban River Restoration: Conflicts between Sensitive Fish Species and Recreational Users

Directory of Open Access Journals (Sweden)

Aude Zingraff-Hamed

2018-05-01

Full Text Available Urban rivers are socioecological systems, and restored habitats may be attractive to both sensitive species and recreationists. Understanding the potential conflicts between ecological and recreational values is a critical issue for the development of a sustainable river-management plan. Habitat models are very promising tools for the ecological evaluation of river restoration projects that are already concluded, ongoing, or even to be planned. With our paper, we make a first attempt at integrating recreational user pressure into habitat modeling. The objective of this study was to analyze whether human impact is likely to hinder the re-establishment of a target species despite the successful restoration of physical habitat structures in the case of the restoration of the Isar River in Munich (Germany and the target fish species Chondostroma nasus L. Our analysis combined high-resolution 2D hydrodynamic modeling with mapping of recreational pressure and used an expert-based procedure for modeling habitat suitability. The results are twofold: (1 the restored river contains suitable physical habitats for population conservation but has low suitability for recruitment; (2 densely used areas match highly suitable habitats for C. nasus. In the future, the integrated modeling procedure presented here may allow ecological refuge for sensitive target species to be included in the design of restoration and may help in the development of visitor-management plans to safeguard biodiversity and recreational ecosystem services.

Determinants of palm species distributions across Africa: the relative roles of climate, non-climatic environmental factors, and spatial constraints

DEFF Research Database (Denmark)

Overgaard, Anne Blach; Svenning, J.-C.; Dransfield, John

2010-01-01

-climatic environmental predictors, the latter having no discernible effect beyond the climatic control. Hence, at the continental scale, climate constitutes the only strong environmental control of palm species distributions in Africa. With regard to the most important climatic predictors of African palm distributions......, water-related factors were most important for 25 of the 29 species analysed. The strong response of palm distributions to climate in combination with the importance of non-environmental spatial constraints suggests that African palms will be sensitive to future climate changes, but that their ability...

Anxiety sensitivity mediates relations between emotional disorders and smoking.

Science.gov (United States)

Zvolensky, Michael J; Farris, Samantha G; Leventhal, Adam M; Schmidt, Norman B

2014-09-01

Research has documented consistent and robust relations between emotional disorders (i.e., depressive and anxiety disorders) and smoking. Yet, it is presently unclear whether anxiety sensitivity--the fear of aversive internal anxiety states--accounts for the relations between emotional disorders and various smoking processes, including nicotine dependence, perceived barriers to smoking cessation, and severity of problematic symptoms during past cessation attempts. Participants (N = 465) were treatment-seeking daily tobacco smokers recruited as part of a larger tobacco-cessation study. Baseline (pretreatment) data were utilized. Emotional disorders were assessed via clinical diagnostic interview; self-report measures were used to assess anxiety sensitivity and 3 criterion variables: nicotine dependence, barriers to smoking cessation, and severity of problematic symptoms while quitting in past attempts. Emotional disorders were predictive of higher levels of nicotine dependence, greater perceived barriers to cessation, and greater severity of problematic symptoms while attempting to quit in the past; each of these relations were accounted for by the indirect effect of anxiety sensitivity. The present findings suggest that anxiety sensitivity may be an important transdiagnostic construct in explicating the nature of the relations between emotional disorders and various smoking processes.

Staphyloxanthin photobleaching sensitizes methicillin-resistant Staphylococcus aureus to reactive oxygen species attack

Science.gov (United States)

Dong, Pu-Ting; Mohammad, Haroon; Hui, Jie; Wang, Xiaoyu; Li, Junjie; Liang, Lijia; Seleem, Mohamed N.; Cheng, Ji-Xin

2018-02-01

Given that the dearth of new antibiotic development loads an existential burden on successful infectious disease therapy, health organizations are calling for alternative approaches to combat methicillin-resistant Staphylococcus aureus (MRSA) infections. Here, we report a drug-free photonic approach to eliminate MRSA through photobleaching of staphyloxanthin, an indispensable membrane-bound antioxidant of S. aureus. The photobleaching process, uncovered through a transient absorption imaging study and quantitated by absorption spectroscopy and mass spectrometry, decomposes staphyloxanthin, and sensitizes MRSA to reactive oxygen species attack. Consequently, staphyloxanthin bleaching by low-level blue light eradicates MRSA synergistically with external or internal reactive oxygen species. The effectiveness of this synergistic therapy is validated in MRSA culture, MRSAinfected macrophage cells. Collectively, these findings highlight broad applications of staphyloxanthin photobleaching for treatment of MRSA infections.

Mapping seabird sensitivity to offshore wind farms.

Science.gov (United States)

Bradbury, Gareth; Trinder, Mark; Furness, Bob; Banks, Alex N; Caldow, Richard W G; Hume, Duncan

2014-01-01

We present a Geographic Information System (GIS) tool, SeaMaST (Seabird Mapping and Sensitivity Tool), to provide evidence on the use of sea areas by seabirds and inshore waterbirds in English territorial waters, mapping their relative sensitivity to offshore wind farms. SeaMaST is a freely available evidence source for use by all connected to the offshore wind industry and will assist statutory agencies in assessing potential risks to seabird populations from planned developments. Data were compiled from offshore boat and aerial observer surveys spanning the period 1979-2012. The data were analysed using distance analysis and Density Surface Modelling to produce predicted bird densities across a grid covering English territorial waters at a resolution of 3 km×3 km. Coefficients of Variation were estimated for each grid cell density, as an indication of confidence in predictions. Offshore wind farm sensitivity scores were compiled for seabird species using English territorial waters. The comparative risks to each species of collision with turbines and displacement from operational turbines were reviewed and scored separately, and the scores were multiplied by the bird density estimates to produce relative sensitivity maps. The sensitivity maps reflected well the amassed distributions of the most sensitive species. SeaMaST is an important new tool for assessing potential impacts on seabird populations from offshore development at a time when multiple large areas of development are proposed which overlap with many seabird species' ranges. It will inform marine spatial planning as well as identifying priority areas of sea usage by marine birds. Example SeaMaST outputs are presented.

Modeled dosage-response relationship on the net photosynthetic rate for the sensitivity to acid rain of 21 plant species.

Science.gov (United States)

Deng, Shihuai; Gou, Shuzhen; Sun, Baiye; Lv, Wenlin; Li, Yuanwei; Peng, Hong; Xiao, Hong; Yang, Gang; Wang, Yingjun

2012-08-01

This study investigated the sensitivity of plant species to acid rain based on the modeled dosage-response relationship on the net photosynthetic rate (P (N)) of 21 types of plant species, subjected to the exposure of simulated acid rain (SAR) for 5 times during a period of 50 days. Variable responses of P (N) to SAR occurred depending on the type of plant. A majority (13 species) of the dosage-response relationship could be described by an S-shaped curve and be fitted with the Boltzmann model. Model fitting allowed quantitative evaluation of the dosage-response relationship and an accurate estimation of the EC(10), termed as the pH of the acid rain resulting in a P (N) 10 % lower than the reference value. The top 9 species (Camellia sasanqua, Cinnamomum camphora, etc. EC(10) ≤ 3.0) are highly endurable to very acid rain. The rare, relict plant Metasequoia glyptostroboides was the most sensitive species (EC(10) = 5.1) recommended for protection.

Growth and Physiological Responses of Phaseolus Species to Salinity Stress

Directory of Open Access Journals (Sweden)

J. S. Bayuelo-Jiménez

2012-01-01

Full Text Available This paper reports the changes on growth, photosynthesis, water relations, soluble carbohydrate, and ion accumulation, for two salt-tolerant and two salt-sensitive Phaseolus species grown under increasing salinity (0, 60 and 90 mM NaCl. After 20 days exposure to salt, biomass was reduced in all species to a similar extent (about 56%, with the effect of salinity on relative growth rate (RGR confined largely to the first week. RGR of salt-tolerant species was reduced by salinity due to leaf area ratio (LAR reduction rather than a decline in photosynthetic capacity, whereas unit leaf rate and LAR were the key factors in determining RGR on salt-sensitive species. Photosynthetic rate and stomatal conductance decreased gradually with salinity, showing significant reductions only in salt-sensitive species at the highest salt level. There was little difference between species in the effect of salinity on water relations, as indicated by their positive turgor. Osmotic adjustment occurred in all species and depended on higher K+, Na+, and Cl− accumulation. Despite some changes in soluble carbohydrate accumulation induced by salt stress, no consistent contributions in osmotic adjustment could be found in this study. Therefore, we suggest that tolerance to salt stress is largely unrelated to carbohydrate accumulation in Phaseolus species.

Studies on the sensitivity of several plant species to fluorine gases in Valais

Energy Technology Data Exchange (ETDEWEB)

Bolay, A; Bovay, E

1965-01-01

Analysis of apricot, apple and vine leaves showed that at leaf fluorine concentrations up to 25 p.p.m. the foliage was generally free of burns, except that of apricot which showed some damage at a level of 15 p.p.m. Between 26 and 105 p.p.m. the reactions of the foliage were variable, depending on the vegetative state of the plant and on atmospheric conditions (mainly R.H. and rainfall). Above 105 p.p.m. burns were nearly always present on apricot and vine leaves; for apple foliage the toxic level was about 160 p.p.m. The 75 plant species studied were divided into 4 categories depending on their susceptibility to fluorine damage; very susceptible species were those showing typical burning of the leaves when the fluorine content of apricot and vine leaves growing in the immediate vicinity was lower than 100 p.p.m.; susceptible species were those showing necrosis when the fluorine content of apricot leaves was slightly higher than 100 p.p.m.; species of low sensitivity showed necrosis only in heavily polluted zones; and tolerant species were those able to store over 500 p.p.m. fluorine in their leaves without showing visible damage. The very susceptible species may be used as indicators of fluorine in the atmosphere.

Monitoring Sensitive Bat Species at Los Alamos National Laboratory

Energy Technology Data Exchange (ETDEWEB)

Schoenberg, Kari M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2014-01-15

Bats play a critical role in ecosystems and are vulnerable to disturbance and disruption by human activities. In recent decades, bat populations in the United States and elsewhere have decreased tremendously. There are 47 different species of bat in the United States and 28 of these occur in New Mexico with 15 different species documented at the Los Alamos National Laboratory (LANL) and surrounding areas. Euderma maculatum(the spotted bat) is listed as “threatened” by the state of New Mexico and is known to occur at LANL. Four other species of bats are listed as “sensitive” and also occur here. In 1995, a four year study was initiated at LANL to assess the status of bat species of concern, elucidate distribution and relative abundance, and obtain information on roosting sites. There have been no definitive studies since then. Biologists in the Environmental Protection Division at LANL initiated a multi-year monitoring program for bats in May 2013 to implement the Biological Resources Management Plan. The objective of this ongoing study is to monitor bat species diversity and seasonal activity over time at LANL. Bat species diversity and seasonal activity were measured using an acoustic bat detector, the Pettersson D500X. This ultrasound recording unit is intended for long-term, unattended recording of bat and other high frequency animal calls. During 2013, the detector was deployed at two locations around LANL. Study sites were selected based on proximity to water where bats may be foraging. Recorded bat calls were analyzed using Sonobat, software that can help determine specific species of bat through their calls. A list of bat species at the two sites was developed and compared to lists from previous studies. Species diversity and seasonal activity, measured as the number of call sequences recorded each month, were compared between sites and among months. A total of 17,923 bat calls were recorded representing 15 species. Results indicate that there is a

Rapid molecular technique to distinguish Fusarium species

CSIR Research Space (South Africa)

Lodolo, EJ

1993-03-01

Full Text Available The nuclear DNA (nDNA) of different isolates of three closely related, toxin-producing Fusarium species, F. moniliforme, F. nygamai and F. napiforme, was compared to ascertain the sensitivity of a molecular method to distinguish these three species...

Mapping seabird sensitivity to offshore wind farms.

Directory of Open Access Journals (Sweden)

Gareth Bradbury

Full Text Available We present a Geographic Information System (GIS tool, SeaMaST (Seabird Mapping and Sensitivity Tool, to provide evidence on the use of sea areas by seabirds and inshore waterbirds in English territorial waters, mapping their relative sensitivity to offshore wind farms. SeaMaST is a freely available evidence source for use by all connected to the offshore wind industry and will assist statutory agencies in assessing potential risks to seabird populations from planned developments. Data were compiled from offshore boat and aerial observer surveys spanning the period 1979-2012. The data were analysed using distance analysis and Density Surface Modelling to produce predicted bird densities across a grid covering English territorial waters at a resolution of 3 km×3 km. Coefficients of Variation were estimated for each grid cell density, as an indication of confidence in predictions. Offshore wind farm sensitivity scores were compiled for seabird species using English territorial waters. The comparative risks to each species of collision with turbines and displacement from operational turbines were reviewed and scored separately, and the scores were multiplied by the bird density estimates to produce relative sensitivity maps. The sensitivity maps reflected well the amassed distributions of the most sensitive species. SeaMaST is an important new tool for assessing potential impacts on seabird populations from offshore development at a time when multiple large areas of development are proposed which overlap with many seabird species' ranges. It will inform marine spatial planning as well as identifying priority areas of sea usage by marine birds. Example SeaMaST outputs are presented.

Scrambled eggs: A highly sensitive molecular diagnostic workflow for Fasciola species specific detection from faecal samples.

Directory of Open Access Journals (Sweden)

Nichola Eliza Davies Calvani

2017-09-01

Full Text Available Fasciolosis, due to Fasciola hepatica and Fasciola gigantica, is a re-emerging zoonotic parasitic disease of worldwide importance. Human and animal infections are commonly diagnosed by the traditional sedimentation and faecal egg-counting technique. However, this technique is time-consuming and prone to sensitivity errors when a large number of samples must be processed or if the operator lacks sufficient experience. Additionally, diagnosis can only be made once the 12-week pre-patent period has passed. Recently, a commercially available coprological antigen ELISA has enabled detection of F. hepatica prior to the completion of the pre-patent period, providing earlier diagnosis and increased throughput, although species differentiation is not possible in areas of parasite sympatry. Real-time PCR offers the combined benefits of highly sensitive species differentiation for medium to large sample sizes. However, no molecular diagnostic workflow currently exists for the identification of Fasciola spp. in faecal samples.A new molecular diagnostic workflow for the highly-sensitive detection and quantification of Fasciola spp. in faecal samples was developed. The technique involves sedimenting and pelleting the samples prior to DNA isolation in order to concentrate the eggs, followed by disruption by bead-beating in a benchtop homogeniser to ensure access to DNA. Although both the new molecular workflow and the traditional sedimentation technique were sensitive and specific, the new molecular workflow enabled faster sample throughput in medium to large epidemiological studies, and provided the additional benefit of speciation. Further, good correlation (R2 = 0.74-0.76 was observed between the real-time PCR values and the faecal egg count (FEC using the new molecular workflow for all herds and sampling periods. Finally, no effect of storage in 70% ethanol was detected on sedimentation and DNA isolation outcomes; enabling transport of samples from endemic

Scrambled eggs: A highly sensitive molecular diagnostic workflow for Fasciola species specific detection from faecal samples

Science.gov (United States)

Calvani, Nichola Eliza Davies; Windsor, Peter Andrew; Bush, Russell David

2017-01-01

Background Fasciolosis, due to Fasciola hepatica and Fasciola gigantica, is a re-emerging zoonotic parasitic disease of worldwide importance. Human and animal infections are commonly diagnosed by the traditional sedimentation and faecal egg-counting technique. However, this technique is time-consuming and prone to sensitivity errors when a large number of samples must be processed or if the operator lacks sufficient experience. Additionally, diagnosis can only be made once the 12-week pre-patent period has passed. Recently, a commercially available coprological antigen ELISA has enabled detection of F. hepatica prior to the completion of the pre-patent period, providing earlier diagnosis and increased throughput, although species differentiation is not possible in areas of parasite sympatry. Real-time PCR offers the combined benefits of highly sensitive species differentiation for medium to large sample sizes. However, no molecular diagnostic workflow currently exists for the identification of Fasciola spp. in faecal samples. Methodology/Principal findings A new molecular diagnostic workflow for the highly-sensitive detection and quantification of Fasciola spp. in faecal samples was developed. The technique involves sedimenting and pelleting the samples prior to DNA isolation in order to concentrate the eggs, followed by disruption by bead-beating in a benchtop homogeniser to ensure access to DNA. Although both the new molecular workflow and the traditional sedimentation technique were sensitive and specific, the new molecular workflow enabled faster sample throughput in medium to large epidemiological studies, and provided the additional benefit of speciation. Further, good correlation (R2 = 0.74–0.76) was observed between the real-time PCR values and the faecal egg count (FEC) using the new molecular workflow for all herds and sampling periods. Finally, no effect of storage in 70% ethanol was detected on sedimentation and DNA isolation outcomes; enabling

Scrambled eggs: A highly sensitive molecular diagnostic workflow for Fasciola species specific detection from faecal samples.

Science.gov (United States)

Calvani, Nichola Eliza Davies; Windsor, Peter Andrew; Bush, Russell David; Šlapeta, Jan

2017-09-01

Fasciolosis, due to Fasciola hepatica and Fasciola gigantica, is a re-emerging zoonotic parasitic disease of worldwide importance. Human and animal infections are commonly diagnosed by the traditional sedimentation and faecal egg-counting technique. However, this technique is time-consuming and prone to sensitivity errors when a large number of samples must be processed or if the operator lacks sufficient experience. Additionally, diagnosis can only be made once the 12-week pre-patent period has passed. Recently, a commercially available coprological antigen ELISA has enabled detection of F. hepatica prior to the completion of the pre-patent period, providing earlier diagnosis and increased throughput, although species differentiation is not possible in areas of parasite sympatry. Real-time PCR offers the combined benefits of highly sensitive species differentiation for medium to large sample sizes. However, no molecular diagnostic workflow currently exists for the identification of Fasciola spp. in faecal samples. A new molecular diagnostic workflow for the highly-sensitive detection and quantification of Fasciola spp. in faecal samples was developed. The technique involves sedimenting and pelleting the samples prior to DNA isolation in order to concentrate the eggs, followed by disruption by bead-beating in a benchtop homogeniser to ensure access to DNA. Although both the new molecular workflow and the traditional sedimentation technique were sensitive and specific, the new molecular workflow enabled faster sample throughput in medium to large epidemiological studies, and provided the additional benefit of speciation. Further, good correlation (R2 = 0.74-0.76) was observed between the real-time PCR values and the faecal egg count (FEC) using the new molecular workflow for all herds and sampling periods. Finally, no effect of storage in 70% ethanol was detected on sedimentation and DNA isolation outcomes; enabling transport of samples from endemic to non

Future Needs and Recommendations in the Development of Species Sensitivity Distributions: Estimating Toxicity Thresholds for Aquatic Ecological Communities and Assessing Impacts of Chemical Exposures

Science.gov (United States)

A species sensitivity distribution (SSD) is a probability model of the variation of species sensitivities to a stressor, in particular chemical exposure. The SSD approach has been used as a decision support tool in environmental protection and management since the 1980s, and the ...

Ethical and Animal Welfare Considerations in Relation to Species Selection for Animal Experimentation.

Science.gov (United States)

Webster, John

2014-12-03

Ethical principles governing the conduct of experiments with animals are reviewed, especially those relating to the choice of species. Legislation requires that the potential harm to animals arising from any procedure should be assessed in advance and justified in terms of its possible benefit to society. Potential harms may arise both from the procedures and the quality of the animals' lifetime experience. The conventional approach to species selection is to use animals with the "lowest degree of neurophysiological sensitivity". However; this concept should be applied with extreme caution in the light of new knowledge. The capacity to experience pain may be similar in mammals, birds and fish. The capacity to suffer from fear is governed more by sentience than cognitive ability, so it cannot be assumed that rodents or farm animals suffer less than dogs or primates. I suggest that it is unethical to base the choice of species for animal experimentation simply on the basis that it will cause less distress within society. A set of responsibilities is outlined for each category of moral agent. These include regulators, operators directly concerned with the conduct of scientific experiments and toxicology trials, veterinarians and animal care staff; and society at large.

Efficient distinction of invasive aquatic plant species from non-invasive related species using DNA barcoding.

Science.gov (United States)

Ghahramanzadeh, R; Esselink, G; Kodde, L P; Duistermaat, H; van Valkenburg, J L C H; Marashi, S H; Smulders, M J M; van de Wiel, C C M

2013-01-01

Biological invasions are regarded as threats to global biodiversity. Among invasive aliens, a number of plant species belonging to the genera Myriophyllum, Ludwigia and Cabomba, and to the Hydrocharitaceae family pose a particular ecological threat to water bodies. Therefore, one would try to prevent them from entering a country. However, many related species are commercially traded, and distinguishing invasive from non-invasive species based on morphology alone is often difficult for plants in a vegetative stage. In this regard, DNA barcoding could become a good alternative. In this study, 242 samples belonging to 26 species from 10 genera of aquatic plants were assessed using the chloroplast loci trnH-psbA, matK and rbcL. Despite testing a large number of primer sets and several PCR protocols, the matK locus could not be amplified or sequenced reliably and therefore was left out of the analysis. Using the other two loci, eight invasive species could be distinguished from their respective related species, a ninth one failed to produce sequences of sufficient quality. Based on the criteria of universal application, high sequence divergence and level of species discrimination, the trnH-psbA noncoding spacer was the best performing barcode in the aquatic plant species studied. Thus, DNA barcoding may be helpful with enforcing a ban on trade of such invasive species, such as is already in place in the Netherlands. This will become even more so once DNA barcoding would be turned into machinery routinely operable by a nonspecialist in botany and molecular genetics. © 2012 Blackwell Publishing Ltd.

Female nurses' sensitivity to male genitalia-related care in mainland China.

Science.gov (United States)

Zang, Yu-Li; Chung, Loretta Y F; Wong, Thomas K S; Chan, Moon Fai

2012-02-01

To discover the latent psychosocial construct of female nurses' sensitivity to male genitalia-related care in the context of sexual conservativeness. Many nursing activities involve direct exposure or contact with male external genitalia. In the sexually conservative culture and the predominance of female nurses, this area is the subject of continuing interest and investigation. Methodological research design. An item pool related to male genitalia-related care was generated through a panel of experts and then reduced to a short form questionnaire, the Female Nurses' Sensitivity to Male Genitalia Related Care scale. Using data from a purposive sample of 588 female nurses, the structure of the questionnaire was examined using structural equation modelling. The validity was examined against existing scales. The 13-item Female Nurses' Sensitivity to Male Genitalia Related Care scale has a two-factor structure with high internal consistency (α = 0·87) and test-retest reliability of 0·90. Nearly all model fit measures reach the criteria of being an acceptable model fit except chi-squared statistics. Scores on Female Nurses' Sensitivity to Male Genitalia Related Care can be best predicted by that of brief Fear of Negative Evaluation Scale, Embarrassability Scale and Situational Susceptibility to Embarrassment Scale. The anxiety of projecting a positive image and the pursuit of sexual propriety may underpin female nurses' sensitivity to male genitalia-related care. This trait can be measured by the 13-item female nurses' sensitivity-male genitalia-related care scale with satisfactory psychometric properties including internal consistency, reliability, content validity and construct validity. Particular attention shall be paid to the negative effects of social rules or norms including sexual propriety rules over (female) nurses' perceptions, attitudes and behaviours. Strengthening nursing education in this regard is important to overcome negative effects on female

Subcellular differences in handling Cu excess in three freshwater fish species contributes greatly to their differences in sensitivity to Cu

International Nuclear Information System (INIS)

Eyckmans, Marleen; Blust, Ronny; De Boeck, Gudrun

2012-01-01

Since changes in metal distribution among tissues and subcellular fractions can provide insights in metal toxicity and tolerance, we investigated this partitioning of Cu in gill and liver tissue of rainbow trout (Oncorhynchus mykiss), common carp (Cyprinus carpio) and gibel carp (Carassius auratus gibelio). These fish species are known to differ in their sensitivity to Cu exposure with gibel carp being the most tolerant and rainbow trout the most sensitive. After an exposure to 50 μg/l (0.79 μM) Cu for 24 h, 3 days, 1 week and 1 month, gills and liver of control and exposed fish were submitted to a differential centrifugation procedure. Interestingly, there was a difference in accumulated Cu in the three fish species, even in control fishes. Where the liver of rainbow trout showed extremely high Cu concentrations under control conditions, the amount of Cu accumulated in their gills was much less than in common and gibel carp. At the subcellular level, the gills of rainbow trout appeared to distribute the additional Cu exclusively in the biologically active metal pool (BAM; contains heat-denaturable fraction and organelle fraction). A similar response could be seen in gill tissue of common carp, although the percentage of Cu in the BAM of common carp was lower compared to rainbow trout. Gill tissue of gibel carp accumulated more Cu in the biologically inactive metal pool (BIM compared to BAM; contains heat-stable fraction and metal-rich granule fraction). The liver of rainbow trout seemed much more adequate in handling the excess Cu (compared to its gills), since the storage of Cu in the BIM increased. Furthermore, the high % of Cu in the metal-rich granule fraction and heat-stable fraction in the liver of common carp and especially gibel carp together with the better Cu handling in gill tissue, pointed out the ability of the carp species to minimize the disadvantages related to Cu stress. The differences in Cu distribution at the subcellular level of gills and

Subcellular differences in handling Cu excess in three freshwater fish species contributes greatly to their differences in sensitivity to Cu

Energy Technology Data Exchange (ETDEWEB)

Eyckmans, Marleen, E-mail: marleen.eyckmans@ua.ac.be [Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); Blust, Ronny; De Boeck, Gudrun [Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium)

2012-08-15

Since changes in metal distribution among tissues and subcellular fractions can provide insights in metal toxicity and tolerance, we investigated this partitioning of Cu in gill and liver tissue of rainbow trout (Oncorhynchus mykiss), common carp (Cyprinus carpio) and gibel carp (Carassius auratus gibelio). These fish species are known to differ in their sensitivity to Cu exposure with gibel carp being the most tolerant and rainbow trout the most sensitive. After an exposure to 50 {mu}g/l (0.79 {mu}M) Cu for 24 h, 3 days, 1 week and 1 month, gills and liver of control and exposed fish were submitted to a differential centrifugation procedure. Interestingly, there was a difference in accumulated Cu in the three fish species, even in control fishes. Where the liver of rainbow trout showed extremely high Cu concentrations under control conditions, the amount of Cu accumulated in their gills was much less than in common and gibel carp. At the subcellular level, the gills of rainbow trout appeared to distribute the additional Cu exclusively in the biologically active metal pool (BAM; contains heat-denaturable fraction and organelle fraction). A similar response could be seen in gill tissue of common carp, although the percentage of Cu in the BAM of common carp was lower compared to rainbow trout. Gill tissue of gibel carp accumulated more Cu in the biologically inactive metal pool (BIM compared to BAM; contains heat-stable fraction and metal-rich granule fraction). The liver of rainbow trout seemed much more adequate in handling the excess Cu (compared to its gills), since the storage of Cu in the BIM increased. Furthermore, the high % of Cu in the metal-rich granule fraction and heat-stable fraction in the liver of common carp and especially gibel carp together with the better Cu handling in gill tissue, pointed out the ability of the carp species to minimize the disadvantages related to Cu stress. The differences in Cu distribution at the subcellular level of gills

Climate-Related Local Extinctions Are Already Widespread among Plant and Animal Species.

Directory of Open Access Journals (Sweden)

John J Wiens

2016-12-01

Full Text Available Current climate change may be a major threat to global biodiversity, but the extent of species loss will depend on the details of how species respond to changing climates. For example, if most species can undergo rapid change in their climatic niches, then extinctions may be limited. Numerous studies have now documented shifts in the geographic ranges of species that were inferred to be related to climate change, especially shifts towards higher mean elevations and latitudes. Many of these studies contain valuable data on extinctions of local populations that have not yet been thoroughly explored. Specifically, overall range shifts can include range contractions at the "warm edges" of species' ranges (i.e., lower latitudes and elevations, contractions which occur through local extinctions. Here, data on climate-related range shifts were used to test the frequency of local extinctions related to recent climate change. The results show that climate-related local extinctions have already occurred in hundreds of species, including 47% of the 976 species surveyed. This frequency of local extinctions was broadly similar across climatic zones, clades, and habitats but was significantly higher in tropical species than in temperate species (55% versus 39%, in animals than in plants (50% versus 39%, and in freshwater habitats relative to terrestrial and marine habitats (74% versus 46% versus 51%. Overall, these results suggest that local extinctions related to climate change are already widespread, even though levels of climate change so far are modest relative to those predicted in the next 100 years. These extinctions will presumably become much more prevalent as global warming increases further by roughly 2-fold to 5-fold over the coming decades.

Effects of pesticides on soil invertebrates in laboratory studies: A review and analysis using species sensitivity distributions

NARCIS (Netherlands)

Frampton, G.K.; Jänsch, S.; Scott-Fordsmand, J.J.; Römbke, J.; Brink, van den P.J.

2006-01-01

Species sensitivity distributions (SSD) and 5% hazardous concentrations (HC5) are distribution-based approaches for assessing environmental risks of pollutants. These methods have potential for application in pesticide risk assessments, but their applicability for assessing pesticide risks to soil

Allergic reactions to vespids: comparison of sensitivities to two species in a Mediterranean area.

Science.gov (United States)

Blanca, M; Miranda, A; Fernandez, J; Terrados, S; Vela, J M; Vega, J M; Gonzalez, J J; Juarez, C

1988-01-01

We have studied a group of twenty-seven patients who suffer allergic reactions to vespids stings. Specific IgE antibodies to venom extracts from Polistes gallicus and Vespula germanica were measured by RAST, and the crossreactivity between the two venoms was compared using the RAST inhibition technique. We concluded that, in southern Spain, sensitization to P. gallicus was more prevalent than that to V. germanica, with 44% of the subjects in this study reacting to P. gallicus compared with 33% to V. germanica. However, there was a considerable degree of crossreactivity between the two species. It is evident that Polistes is an important species in this area; however, both in Spain and other Mediterranean countries, V. germanica venom is used almost exclusively for diagnosis and immunotherapy.

CE of phytosiderophores and related metal species in plants.

Science.gov (United States)

Xuan, Yue; Scheuermann, Enrico B; Meda, Anderson R; Jacob, Peter; von Wirén, Nicolaus; Weber, Günther

2007-10-01

Phytosiderophores (PS) and the closely related substance nicotianamine (NA) are key substances in metal uptake into graminaceous plants. Here, the CE separation of these substances and related metal species is demonstrated. In particular, the three PS 2'-deoxymugineic acid (DMA), mugineic acid (MA), and 3-epi-hydroxymugineic acid (epi-HMA), and NA, are separated using MES/Tris buffer at pH 7.3. Moreover, three Fe(III) species of the different PS are separated without any stability problems, which are often present in chromatographic analyses. Also divalent metal species of Cu, Ni, and Zn with the ligands DMA and NA are separated with the same method. By using a special, zwitterionic CE capillary, even the separation of two isomeric Fe(III) chelates with the ligand ethylenediamine-N,N'-bis(o-hydroxyphenyl)acetic acid (EDDHA) is possible (i.e., meso-Fe(III)-EDDHA and rac-Fe(III)-EDDHA), and for fast separations of NA and respective divalent and trivalent metal species, a polymer CE microchip with suppressed EOF is described. The proposed CE method is applicable to real plant samples, and enables to detect changes of metal species (Cu-DMA, Ni-NA), which are directly correlated to biological processes.

Landscape- vs gap-level controls on the abundance of a fire-sensitive, late-successional tree species.

Science.gov (United States)

Michael C. Wimberly; Thomas A. Spies

2002-01-01

Tsuga heterophylla (western hemlock), a fire-sensitive, late-successional tree species, is an important component of old-growth forests in the Pacific Northwest, USA. In the Oregon Coast Range, however, T. heterophylla occurs at low densities in or is completely absent from many conifer stands. We used a cellular automata-based...

Molecular relationships between closely related strains and species of nematodes

Science.gov (United States)

Butler, M. H.; Wall, S. M.; Luehrsen, K. R.; Fox, G. E.; Hecht, R. M.

1981-01-01

Electrophoretic comparisons have been made for 24 enzymes in the Bergerac and Bristol strains of Caenorhabditis elegans and the related species, Caenorhabditis briggsae. No variation was detected between the two strains of C. elegans. In contrast, the two species, C. elegans and C. briggsae exhibited electrophoretic differences in 22 of 24 enzymes. A consensus 5S rRNA sequence was determined for C. elegans and found to be identical to that from C. briggsae. By analogy with other species with relatively well established fossil records it can be inferred that the time of divergence between the two nematode species is probably in the tens of millions of years. The limited anatomical evolution during a time period in which proteins undergo extensive changes supports the hypothesis that anatomical evolution is not dependent on overall protein changes.

Twin target self-amplification-based DNA machine for highly sensitive detection of cancer-related gene.

Science.gov (United States)

Xu, Huo; Jiang, Yifan; Liu, Dengyou; Liu, Kai; Zhang, Yafeng; Yu, Suhong; Shen, Zhifa; Wu, Zai-Sheng

2018-06-29

The sensitive detection of cancer-related genes is of great significance for early diagnosis and treatment of human cancers, and previous isothermal amplification sensing systems were often based on the reuse of target DNA, the amplification of enzymatic products and the accumulation of reporting probes. However, no reporting probes are able to be transformed into target species and in turn initiate the signal of other probes. Herein we reported a simple, isothermal and highly sensitive homogeneous assay system for tumor suppressor p53 gene detection based on a new autonomous DNA machine, where the signaling probe, molecular beacon (MB), was able to execute the function similar to target DNA besides providing the common signal. In the presence of target p53 gene, the operation of DNA machine can be initiated, and cyclical nucleic acid strand-displacement polymerization (CNDP) and nicking/polymerization cyclical amplification (NPCA) occur, during which the MB was opened by target species and cleaved by restriction endonuclease. In turn, the cleaved fragments could activate the next signaling process as target DNA did. According to the functional similarity, the cleaved fragment was called twin target, and the corresponding fashion to amplify the signal was named twin target self-amplification. Utilizing this newly-proposed DNA machine, the target DNA could be detected down to 0.1 pM with a wide dynamic range (6 orders of magnitude) and single-base mismatched targets were discriminated, indicating a very high assay sensitivity and good specificity. In addition, the DNA machine was not only used to screen the p53 gene in complex biological matrix but also was capable of practically detecting genomic DNA p53 extracted from A549 cell line. This indicates that the proposed DNA machine holds the potential application in biomedical research and early clinical diagnosis. Copyright © 2018 Elsevier B.V. All rights reserved.

Input-variable sensitivity assessment for sediment transport relations

Science.gov (United States)

Fernández, Roberto; Garcia, Marcelo H.

2017-09-01

A methodology to assess input-variable sensitivity for sediment transport relations is presented. The Mean Value First Order Second Moment Method (MVFOSM) is applied to two bed load transport equations showing that it may be used to rank all input variables in terms of how their specific variance affects the overall variance of the sediment transport estimation. In sites where data are scarce or nonexistent, the results obtained may be used to (i) determine what variables would have the largest impact when estimating sediment loads in the absence of field observations and (ii) design field campaigns to specifically measure those variables for which a given transport equation is most sensitive; in sites where data are readily available, the results would allow quantifying the effect that the variance associated with each input variable has on the variance of the sediment transport estimates. An application of the method to two transport relations using data from a tropical mountain river in Costa Rica is implemented to exemplify the potential of the method in places where input data are limited. Results are compared against Monte Carlo simulations to assess the reliability of the method and validate its results. For both of the sediment transport relations used in the sensitivity analysis, accurate knowledge of sediment size was found to have more impact on sediment transport predictions than precise knowledge of other input variables such as channel slope and flow discharge.

Relative sensitivity of formability to anisotropy

International Nuclear Information System (INIS)

Logan, R.W.; Maker, B.N.

1997-01-01

This work compares the relative importance of material anisotropy in sheet forming as compared to other material and process variables. The comparison is made quantitative by the use of normalized dependencies of depth to failure (forming limit is reached) on various measures of anisotropy, as well as strain and rate sensitivity, friction, and tooling. Comparisons are made for a variety of forming processes examined previously in the literature as well as two examples of complex stampings in this work. 7 The examples rover a range from nearly pure draw to nearly pure stretch situations, and show that for materials following a quadratic yield criterion, anisotropy is among the most sensitive parameters influencing formability. For materials following higher-exponent yield criteria, the dependency is milder but is still of the order of most other process parameters. However, depending on the particular forming operation, it is shown that in some cases anisotropy may be ignored, whereas in others its consideration is crucial to a good quality analysis

Variability in larval gut pH regulation defines sensitivity to ocean acidification in six species of the Ambulacraria superphylum.

Science.gov (United States)

Hu, Marian; Tseng, Yung-Che; Su, Yi-Hsien; Lein, Etienne; Lee, Hae-Gyeong; Lee, Jay-Ron; Dupont, Sam; Stumpp, Meike

2017-10-11

The unusual rate and extent of environmental changes due to human activities may exceed the capacity of marine organisms to deal with this phenomenon. The identification of physiological systems that set the tolerance limits and their potential for phenotypic buffering in the most vulnerable ontogenetic stages become increasingly important to make large-scale projections. Here, we demonstrate that the differential sensitivity of non-calcifying Ambulacraria (echinoderms and hemichordates) larvae towards simulated ocean acidification is dictated by the physiology of their digestive systems. Gastric pH regulation upon experimental ocean acidification was compared in six species of the superphylum Ambulacraria. We observed a strong correlation between sensitivity to ocean acidification and the ability to regulate gut pH. Surprisingly, species with tightly regulated gastric pH were more sensitive to ocean acidification. This study provides evidence that strict maintenance of highly alkaline conditions in the larval gut of Ambulacraria early life stages may dictate their sensitivity to decreases in seawater pH. These findings highlight the importance of identifying and understanding pH regulatory systems in marine larval stages that may contribute to substantial energetic challenges under near-future ocean acidification scenarios. © 2017 The Author(s).

German and Korean mothers' sensitivity and related parenting beliefs

Science.gov (United States)

Ziehm, Jeanette; Trommsdorff, Gisela; Heikamp, Tobias; Park, Seong-Yeon

2013-01-01

This study contributes to a differentiated understanding of maternal sensitivity in cultural and situational context. We investigated differences and similarities in German and Korean mothers' maternal sensitivity. We interviewed 92 German and 100 Korean mothers of first graders about their preference for proactive (anticipating children's needs) or reactive sensitivity (responding to children's direct cues) in different scenarios. Related parenting beliefs were assessed by asking the mothers to explain the reasons why they would prefer specific parenting behaviors. Results revealed significant cultural differences in reactive vs. proactive sensitivity preferences. Overall, German mothers were more likely to indicate that a mother should respond reactively and less likely to report that a mother should act proactively than were Korean mothers. Korean mothers gave preference to both reactive and proactive sensitivity depending on the scenario. With regard to parenting beliefs, analyses revealed that German and Korean mothers who preferred reactive sensitivity mainly explained their choices as attempts to encourage children's development of independence. In contrast, Korean and German mothers with a preference for proactive sensitivity were more likely to report that mothers would assist their children due to their immaturity in dealing with emotional distress. Results are discussed in the framework of the different meanings and functions of maternal sensitivity for socialization in different cultural contexts. PMID:23986740

A probabilistic method for species sensitivity distributions taking into account the inherent uncertainty and variability of effects to estimate environmental risk.

Science.gov (United States)

Gottschalk, Fadri; Nowack, Bernd

2013-01-01

This article presents a method of probabilistically computing species sensitivity distributions (SSD) that is well-suited to cope with distinct data scarcity and variability. First, a probability distribution that reflects the uncertainty and variability of sensitivity is modeled for each species considered. These single species sensitivity distributions are then combined to create an SSD for a particular ecosystem. A probabilistic estimation of the risk is carried out by combining the probability of critical environmental concentrations with the probability of organisms being impacted negatively by these concentrations. To evaluate the performance of the method, we developed SSD and risk calculations for the aquatic environment exposed to triclosan. The case studies showed that the probabilistic results reflect the empirical information well, and the method provides a valuable alternative or supplement to more traditional methods for calculating SSDs based on averaging raw data and/or on using theoretical distributional forms. A comparison and evaluation with single SSD values (5th-percentile [HC5]) revealed the robustness of the proposed method. Copyright © 2012 SETAC.

TOXICITY OF PENTACHLOROPHENOL TO ENDANGERED AND SURROGATE FISH SPECIES

Science.gov (United States)

Water quality criteria (WQC) generally are based on the responses of easily cultured and tested surrogate species. Little is known about the relative sensitivity of surrogate and endangered species. The objective of this study was to compare acute and chronic (early life-stage) ...

Social network size relates to developmental neural sensitivity to biological motion

Directory of Open Access Journals (Sweden)

L.A. Kirby

2018-04-01

Full Text Available The ability to perceive others’ actions and goals from human motion (i.e., biological motion perception is a critical component of social perception and may be linked to the development of real-world social relationships. Adult research demonstrates two key nodes of the brain’s biological motion perception system—amygdala and posterior superior temporal sulcus (pSTS—are linked to variability in social network properties. The relation between social perception and social network properties, however, has not yet been investigated in middle childhood—a time when individual differences in social experiences and social perception are growing. The aims of this study were to (1 replicate past work showing amygdala and pSTS sensitivity to biological motion in middle childhood; (2 examine age-related changes in the neural sensitivity for biological motion, and (3 determine whether neural sensitivity for biological motion relates to social network characteristics in children. Consistent with past work, we demonstrate a significant relation between social network size and neural sensitivity for biological motion in left pSTS, but do not find age-related change in biological motion perception. This finding offers evidence for the interplay between real-world social experiences and functional brain development and has important implications for understanding disorders of atypical social experience. Keywords: Biological motion, Social networks, Middle childhood, Neural specialization, Brain-behavior relations, pSTS

Seasonal variation in parasite infection patterns of marine fish species from the Northern Wadden Sea in relation to interannual temperature fluctuations

Science.gov (United States)

Schade, Franziska M.; Raupach, Michael J.; Mathias Wegner, K.

2016-07-01

Marine environmental conditions are naturally changing throughout the year, affecting life cycles of hosts as well as parasites. In particular, water temperature is positively correlated with the development of many parasites and pathogenic bacteria, increasing the risk of infection and diseases during summer. Interannual temperature fluctuations are likely to alter host-parasite interactions, which may result in profound impacts on sensitive ecosystems. In this context we investigated the parasite and bacterial Vibrionaceae communities of four common small fish species (three-spined stickleback Gasterosteus aculeatus, Atlantic herring Clupea harengus, European sprat Sprattus sprattus and lesser sand eel Ammodytes tobianus) in the Northern Wadden Sea over a period of two years. Overall, we found significantly increased relative diversities of infectious species at higher temperature differentials. On the taxon-specific level some macroparasite species (trematodes, nematodes) showed a shift in infection peaks that followed the water temperatures of preceding months, whereas other parasite groups showed no effects of temperature differentials on infection parameters. Our results show that even subtle changes in seasonal temperatures may shift and modify the phenology of parasites as well as opportunistic pathogens that can have far reaching consequences for sensitive ecosystems.

Perceptual Sensitivity and Response to Strong Stimuli Are Related

Directory of Open Access Journals (Sweden)

Anna C. Bolders

2017-09-01

Full Text Available To shed new light on the long-standing debate about the (independence of sensitivity to weak stimuli and overreactivity to strong stimuli, we examined the relation between these tendencies within the neurobehavioral framework of the Predictive and Reactive Control Systems (PARCS theory (Tops et al., 2010, 2014. Whereas previous studies only considered overreactivity in terms of the individual tendency to experience unpleasant affect (punishment reactivity resulting from strong sensory stimulation, we also took the individual tendency to experience pleasant affect (reward reactivity resulting from strong sensory stimulation into account. According to PARCS theory, these temperamental tendencies overlap in terms of high reactivity toward stimulation, but oppose each other in terms of the response orientation (approach or avoid. PARCS theory predicts that both types of reactivity to strong stimuli relate to sensitivity to weak stimuli, but that these relationships are suppressed due to the opposing relationship between reward and punishment reactivity. We measured punishment and reward reactivity to strong stimuli and sensitivity to weak stimuli using scales from the Adult Temperament Questionnaire (Evans and Rothbart, 2007. Sensitivity was also measured more objectively using the masked auditory threshold. We found that sensitivity to weak stimuli (both self-reported and objectively assessed was positively associated with self-reported punishment and reward reactivity to strong stimuli, but only when these reactivity measures were controlled for each other, implicating a mutual suppression effect. These results are in line with PARCS theory and suggest that sensitivity to weak stimuli and overreactivity are dependent, but this dependency is likely to be obscured if punishment and reward reactivity are not both taken into account.

Bacterial Species and Antibiotic Sensitivity in Korean Patients Diagnosed with Acute Otitis Media and Otitis Media with Effusion.

Science.gov (United States)

Kim, Sang Hoon; Jeon, Eun Ju; Hong, Seok Min; Bae, Chang Hoon; Lee, Ho Yun; Park, Moo Kyun; Byun, Jae Yong; Kim, Myung Gu; Yeo, Seung Geun

2017-04-01

Changes over time in pathogens and their antibiotic sensitivity resulting from the recent overuse and misuse of antibiotics in otitis media (OM) have complicated treatment. This study evaluated changes over 5 years in principal pathogens and their antibiotic sensitivity in patients in Korea diagnosed with acute OM (AOM) and OM with effusion (OME). The study population consisted of 683 patients who visited the outpatient department of otorhinolaryngology in 7 tertiary hospitals in Korea between January 2010 and May 2015 and were diagnosed with acute AOM or OME. Aural discharge or middle ear fluid were collected from patients in the operating room or outpatient department and subjected to tests of bacterial identification and antibiotic sensitivity. The overall bacteria detection rate of AOM was 62.3% and OME was 40.9%. The most frequently isolated Gram-positive bacterial species was coagulase negative Staphylococcus aureus (CNS) followed by methicillin-susceptible S. aureus (MSSA), methicillin-resistant S. aureus (MRSA), and Streptococcus pneumonia (SP), whereas the most frequently isolated Gram-negative bacterium was Pseudomonas aeruginosa (PA). Regardless of OM subtype, ≥ 80% of CNS and MRSA strains were resistant to penicillin (PC) and tetracycline (TC); isolated MRSA strains showed low sensitivity to other antibiotics, with 100% resistant to PC, TC, cefoxitin (CFT), and erythromycin (EM); and isolated PA showed low sensitivity to quinolone antibiotics, including ciprofloxacin (CIP) and levofloxacin (LFX), and to aminoglycosides. Bacterial species and antibiotic sensitivity did not change significantly over 5 years. The rate of detection of MRSA was higher in OME than in previous studies. As bacterial predominance and antibiotic sensitivity could change over time, continuous and periodic surveillance is necessary in guiding appropriate antibacterial therapy. © 2017 The Korean Academy of Medical Sciences.

ENDANGERED SPECIES SENSITIVITY AND ECOLOGICAL RISK ASSESSMENT

Science.gov (United States)

he U.S. Environmental Protection Agency (EPA), U.S. Fish & Wildlife Service, and National Marine Fisheries Service share a common responsibility for the protection of our nation's aquatic species under the Endangered Species Act (ESA) of 1973. The EPA, under the Federal Insectici...

Species-area relationships are controlled by species traits.

Science.gov (United States)

Franzén, Markus; Schweiger, Oliver; Betzholtz, Per-Eric

2012-01-01

The species-area relationship (SAR) is one of the most thoroughly investigated empirical relationships in ecology. Two theories have been proposed to explain SARs: classical island biogeography theory and niche theory. Classical island biogeography theory considers the processes of persistence, extinction, and colonization, whereas niche theory focuses on species requirements, such as habitat and resource use. Recent studies have called for the unification of these two theories to better explain the underlying mechanisms that generates SARs. In this context, species traits that can be related to each theory seem promising. Here we analyzed the SARs of butterfly and moth assemblages on islands differing in size and isolation. We tested whether species traits modify the SAR and the response to isolation. In addition to the expected overall effects on the area, traits related to each of the two theories increased the model fit, from 69% up to 90%. Steeper slopes have been shown to have a particularly higher sensitivity to area, which was indicated by species with restricted range (slope = 0.82), narrow dietary niche (slope= 0.59), low abundance (slope= 0.52), and low reproductive potential (slope = 0.51). We concluded that considering species traits by analyzing SARs yields considerable potential for unifying island biogeography theory and niche theory, and that the systematic and predictable effects observed when considering traits can help to guide conservation and management actions.

Sensitive identification of mycobacterial species using PCR-RFLP on bronchial washings.

Science.gov (United States)

Hidaka, E; Honda, T; Ueno, I; Yamasaki, Y; Kubo, K; Katsuyama, T

2000-03-01

In 98 patients (24 with active pulmonary tuberculosis [TB] lesions, 28 with cured TB lesions, and 46 with nontuberculous opacities [control group] in chest CT scans), we examined whether washing the bronchus after brushing the lesion, then applying polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) to the bronchial washings might be useful for diagnosing TB and nontuberculous mycobacteriosis (NTMosis). After biopsy and brushing with a bronchoscope, the bronchus connecting to the lesion was washed with 20 ml saline. The saline used for washing the brushes (5 ml; brushing sample), and 3 to 10 ml saline aspirated through the forceps channel (washing sample) were examined by PCR-RFLP, which proved able to identify Mycobacterium tuberculosis and seven species of nontuberculous mycobacteria (NTM). The values obtained for the sensitivity of the PCR-RFLP with respect to the brushing sample, the washing sample, and both samples mixed together were 70, 76, and 91%, respectively, when only patients who were culture-positive or radiologically improved after antituberculous therapy were considered as showing true infection. A mixture of brushing and washing samples provides useful material for PCR and culture, and the PCR-RFLP used here is a good method for the simultaneous identification of several species of mycobacterium (including M. tuberculosis).

Genetically modified yeast of the species Issatchenkia orientalis and closely relates species, and fermentation processes using same

Science.gov (United States)

Suominen, Pirkko [Maple Grove, MN; Aristidou, Aristos [Highland Ranch, CO; Pentilla, Merja [Helsinki, FI; Ilmen, Marja [Helsinki, FI; Ruohonen, Laura [Helsinki, FI; Koivuranta, Kari [Vantaa, FI; Roberg-Perez, Kevin [Minneapolis, MN

2012-01-17

Cells of the species Issatchenkia orientalis and closely related yeast species are transformed with a vector to introduce an exogenous lactate dehydrogenase gene. The cells produce lactic acid efficiently and are resistant at low pH, high lactate titer conditions.

Using species sensitivity distribution approach to assess the risks of commonly detected agricultural pesticides to Australia's tropical freshwater ecosystems.

Science.gov (United States)

Pathiratne, Asoka; Kroon, Frederieke J

2016-02-01

To assess the potential impacts of agricultural pesticides on tropical freshwater ecosystems, the present study developed temperature-specific, freshwater species protection concentrations (i.e., ecotoxicity threshold values) for 8 pesticides commonly detected in Australia's tropical freshwaters. Because relevant toxicity data for native tropical freshwater species to assess the ecological risks were mostly absent, scientifically robust toxicity data obtained at ≥20 °C were used for ecologically relevant taxonomic groups representing primary producers and consumers. Species sensitivity distribution (SSD) curves were subsequently generated for predicted chronic exposure using Burrlioz 2.0 software with mixed chronic and converted acute data relevant to exposure conditions at ≥20 °C. Ecotoxicity threshold values for tropical freshwater ecosystem protection were generated for ametryn, atrazine, diuron, metolachlor, and imidacloprid (all moderate reliability), as well as simazine, hexazinone, and tebuthiuron (all low reliability). Using these SSD curves, the retrospective risk assessments for recently reported pesticide concentrations highlight that the herbicides ametryn, atrazine, and diuron are of major concern for ecological health in Australia's tropical freshwater ecosystems. The insecticide imidacloprid also appears to pose an emerging threat to the most sensitive species in tropical freshwater ecosystems. The exposed temperature-specific approach may be applied to develop water quality guideline values for other environmental contaminants detected in tropical freshwater ecosystems until reliable and relevant toxicity data are generated using representative native species. © 2015 SETAC.

Beyond exposure, sensitivity and adaptive capacity: A response based ecological framework to assess species climate change vulnerability

Science.gov (United States)

Fortini, Lucas B.; Schubert, Olivia

2017-01-01

As the impacts of global climate change on species are increasingly evident, there is a clear need to adapt conservation efforts worldwide. Species vulnerability assessments (VAs) are increasingly used to summarize all relevant information to determine a species’ potential vulnerability to climate change and are frequently the first step in informing climate adaptation efforts. VAs commonly integrate multiple sources of information by utilizing a framework that distinguishes factors relevant to species exposure, sensitivity, and adaptive capacity. However, this framework was originally developed for human systems, and its use to evaluate species vulnerability has serious practical and theoretical limitations. By instead defining vulnerability as the degree to which a species is unable to exhibit any of the responses necessary for persistence under climate change (i.e., toleration of projected changes, migration to new climate-compatible areas, enduring in microrefugia, and evolutionary adaptation), we can bring VAs into the realm of ecological science without applying borrowed abstract concepts that have consistently challenged species-centric research and management. This response-based framework to assess species vulnerability to climate change allows better integration of relevant ecological data and past research, yielding results with much clearer implications for conservation and research prioritization.

Climate change sensitivity of the African ivory nut palm, Hyphaene petersiana Klotzsch ex Mart. (Arecaceae) - a keystone species in SE Africa

International Nuclear Information System (INIS)

Blach-Overgaard, A; Svenning, J-C; Balslev, H

2009-01-01

Africa is the most vulnerable continent to future climate change. Profound changes are projected for southwestern Africa with increased drying, notably with delayed onset of the rainy season in September-November, and temperature increases in all seasons. The projected climate changes combined with land-use changes are thought to constitute the main threats to biodiversity in the 21st century. To be able to predict the potential impact on biodiversity, it is crucial to achieve a better insight into the controls of contemporary species ranges. Using species distribution modeling, we assessed the climate sensitivity of the key-stone palm species Hyphaene petersiana (African ivory nut palm) in southern Africa. We tested the relative roles of climate vs. non-climatic range-controls and found that climate had a clear effect on the range of H. petersiana and that especially water-related variables (annual precipitation and precipitation driest quarter) were of high importance. Nevertheless, latitude was the overall most dominant variable, reflecting spatial constraints on the continental-scale distribution. Of the remaining non-climatic factors, soil type and human influence were as important as the climatic factors. A future decrease in annual precipitation below 400 mm and hydrological changes towards drier conditions could cause a dramatic decline in H. petersiana populations, while the influence of temperature changes is less clear. The ongoing, unsustainable utilization pressures on this palm species by humans and livestock are likely to exacerbate the negative effect of future climate changes on its populations, especially, given the expected human population increase in Africa.

Photoreceptor spectral sensitivity in the bumblebee, Bombus impatiens (Hymenoptera: Apidae.

Directory of Open Access Journals (Sweden)

Peter Skorupski

Full Text Available The bumblebee Bombus impatiens is increasingly used as a model in comparative studies of colour vision, or in behavioural studies relying on perceptual discrimination of colour. However, full spectral sensitivity data on the photoreceptor inputs underlying colour vision are not available for B. impatiens. Since most known bee species are trichromatic, with photoreceptor spectral sensitivity peaks in the UV, blue and green regions of the spectrum, data from a related species, where spectral sensitivity measurements have been made, are often applied to B impatiens. Nevertheless, species differences in spectral tuning of equivalent photoreceptor classes may result in peaks that differ by several nm, which may have small but significant effects on colour discrimination ability. We therefore used intracellular recording to measure photoreceptor spectral sensitivity in B. impatiens. Spectral peaks were estimated at 347, 424 and 539 nm for UV, blue and green receptors, respectively, suggesting that this species is a UV-blue-green trichromat. Photoreceptor spectral sensitivity peaks are similar to previous measurements from Bombus terrestris, although there is a significant difference in the peak sensitivity of the blue receptor, which is shifted in the short wave direction by 12-13 nm in B. impatiens compared to B. terrestris.

Aspergillus fumigatus-Related Species in Clinical Practice.

Science.gov (United States)

Lamoth, Frédéric

2016-01-01

Aspergillus fumigatus is the main etiologic agent of invasive aspergillosis (IA). Other Aspergillus species belonging to the section Fumigati (A. fumigatus complex) may occasionally be the cause of IA. These strains are often misidentified, as they cannot be distinguished from A. fumigatus by conventional morphological analysis and sequencing methods. This lack of recognition may have important consequences as these A. fumigatus-related species often display some level of intrinsic resistance to azoles and other antifungal drugs. A. lentulus, A. udagawae, A. viridinutans, and A. thermomutatus (Neosartorya pseudofischeri) have been associated with refractory cases of IA. Microbiologists should be able to suspect the presence of these cryptic species behind a putative A. fumigatus isolate on the basis of some simple characteristics, such as defect in sporulation and/or unusual antifungal susceptibility profile. However, definitive species identification requires specific sequencing analyses of the beta-tubulin or calmodulin genes, which are not available in most laboratories. Multiplex PCR assays or matrix-assisted laser desorption ionization - time-of-flight mass spectrometry (MALDI-TOF MS) gave promising results for rapid and accurate distinction between A. fumigatus and other Aspergillus spp. of the section Fumigati in clinical practice. Improved diagnostic procedures and antifungal susceptibility testing may be helpful for the early detection and management of these particular IA cases.

Assessing the sensitivity of avian species abundance to land cover and climate

Science.gov (United States)

LeBrun, Jaymi J.; Thogmartin, Wayne E.; Thompson, Frank R.; Dijak, William D.; Millspaugh, Joshua J.

2016-01-01

Climate projections for the Midwestern United States predict southerly climates to shift northward. These shifts in climate could alter distributions of species across North America through changes in climate (i.e., temperature and precipitation), or through climate-induced changes on land cover. Our objective was to determine the relative impacts of land cover and climate on the abundance of five bird species in the Central United States that have habitat requirements ranging from grassland and shrubland to forest. We substituted space for time to examine potential impacts of a changing climate by assessing climate and land cover relationships over a broad latitudinal gradient. We found positive and negative relationships of climate and land cover factors with avian abundances. Habitat variables drove patterns of abundance in migratory and resident species, although climate was also influential in predicting abundance for some species occupying more open habitat (i.e., prairie warbler, blue-winged warbler, and northern bobwhite). Abundance of northern bobwhite increased with winter temperature and was the species exhibiting the most significant effect of climate. Models for birds primarily occupying early successional habitats performed better with a combination of habitat and climate variables whereas models of species found in contiguous forest performed best with land cover alone. These varied species-specific responses present unique challenges to land managers trying to balance species conservation over a variety of land covers. Management activities focused on increasing forest cover may play a role in mitigating effects of future climate by providing habitat refugia to species vulnerable to projected changes. Conservation efforts would be best served focusing on areas with high species abundances and an array of habitats. Future work managing forests for resilience and resistance to climate change could benefit species already susceptible to climate impacts.

Aquatic plants: Test species sensitivity and minimum data requirement evaluations for chemical risk assessments and aquatic life criteria development for the USA

Science.gov (United States)

Phytotoxicity results from the publicly-available ECOTOX database were summarized for 20 chemicals and 188 aquatic plants to determine species sensitivities and the ability of a species-limited toxicity data set to serve as a surrogate for a larger data set. The lowest effect con...

Determination of the soil hazardous concentrations of bisphenol A using the species sensitivity approach.

Science.gov (United States)

Kwak, Jin Il; Moon, Jongmin; Kim, Dokyung; Cui, Rongxue; An, Youn-Joo

2018-02-15

This study describes the determination of the species sensitivity distribution (SSD)-based soil hazardous contamination of bisphenol A for environmental risk assessment. We conducted a battery of bioassays, including acute assays using eight species from six different taxonomic groups and chronic assays using five species from four different taxonomic groups. We determined that our dataset satisfied Australia & New Zealand's guidelines for applying the SSD methodology. Finally, the chronic soil HC 5 and HC 50 values for bisphenol A were estimated to be 13.7 and 74.7mg/kg soil, respectively, for soil ecosystem protection against chronic exposure using the data generated from this and previous studies. Because the soil standard values of bisphenol A for protection of the soil ecosystem are not currently available, the HC values of bisphenol A that we suggested based on the SSD approach would be applied as fundamental data to establish soil standards of bisphenol A for soil ecosystem protection. To our knowledge, this is the first study reporting the soil hazardous concentration of bisphenol A for environmental risk assessment. Copyright © 2017 Elsevier B.V. All rights reserved.

Multiplex-PCR As a Rapid and Sensitive Method for Identification of Meat Species in Halal-Meat Products.

Science.gov (United States)

Alikord, Mahsa; Keramat, Javad; Kadivar, Mahdi; Momtaz, Hassan; Eshtiaghi, Mohammad N; Homayouni-Rad, Aziz

2017-01-01

Species identification and authentication in meat products are important subjects for ensuring the health of consumers. The multiplex-PCR amplification and species- specific primer set were used for the identification of horse, donkey, pig and other ruminants in raw and processed meat products. Oligonucleotid primers were designed and patented for amplification of species-specific mitochondrial DNA sequences of each species and samples were prepared from binary meat mixtures. The results showed that meat species were accurately determined in all combinations by multiplex-PCR, and the sensitivity of this method was 0.001 ng, rendering this technique open to and suitable for use in industrial meat products. It is concluded that more fraud is seen in lower percentage industrial meat products than in higher percentage ones. There was also more fraud found in processed products than in raw ones. This rapid and useful test is recommended for quality control firms for applying more rigorous controls over industrial meat products, for the benefit of target consumers. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Contact sensitization from Compositae-containing herbal remedies and cosmetics.

Science.gov (United States)

Paulsen, Evy

2002-10-01

The Compositae (Asteraceae) family of plants is currently an important cause of allergic plant contact dermatitis in Europe. The family comprises some of the oldest and most valued medicinal plants, and the increasing popularity of herbal medicine and cosmetics may theoretically result in a growing number of Compositae sensitizations from these sources. According to the literature at least 15 species, including among others arnica (Arnica montana), German and Roman chamomile (Chamomilla recutita and Chamaemelum nobile), marigold (Calendula officinalis), Echinacea and elecampane (Inula helenium), have been suspected of sensitization or elicitation of Compositae dermatitis. Epidemiological data are available for 2 species only, arnica and German chamomile, the rest of the evidence being anecdotal. Based on this, sensitization seems to occur relatively frequently with a few species such as arnica and elecampane, and occurs rarely with the majority, especially the widely used German chamomile. Sesquiterpene lactones are the most important allergens, but there are a few cases of sensitization from a coumarin, a sesquiterpene alcohol and a thiophene. The risk of elicitation of dermatitis by using Compositae-containing products in Compositae-sensitive individuals is by-and-large unknown.

A Robust Approach to Risk Assessment Based on Species Sensitivity Distributions.

Science.gov (United States)

Monti, Gianna S; Filzmoser, Peter; Deutsch, Roland C

2018-05-03

The guidelines for setting environmental quality standards are increasingly based on probabilistic risk assessment due to a growing general awareness of the need for probabilistic procedures. One of the commonly used tools in probabilistic risk assessment is the species sensitivity distribution (SSD), which represents the proportion of species affected belonging to a biological assemblage as a function of exposure to a specific toxicant. Our focus is on the inverse use of the SSD curve with the aim of estimating the concentration, HCp, of a toxic compound that is hazardous to p% of the biological community under study. Toward this end, we propose the use of robust statistical methods in order to take into account the presence of outliers or apparent skew in the data, which may occur without any ecological basis. A robust approach exploits the full neighborhood of a parametric model, enabling the analyst to account for the typical real-world deviations from ideal models. We examine two classic HCp estimation approaches and consider robust versions of these estimators. In addition, we also use data transformations in conjunction with robust estimation methods in case of heteroscedasticity. Different scenarios using real data sets as well as simulated data are presented in order to illustrate and compare the proposed approaches. These scenarios illustrate that the use of robust estimation methods enhances HCp estimation. © 2018 Society for Risk Analysis.

Aspergillus fumigatus-Related Species in Clinical Practice

Directory of Open Access Journals (Sweden)

Frederic eLamoth

2016-05-01

Full Text Available Aspergillus fumigatus is the main etiologic agent of invasive aspergillosis (IA. Other Aspergillus species belonging to the section Fumigati (A. fumigatus complex may occasionally be the cause of IA. These strains are often misidentified, as they cannot be distinguished from A. fumigatus by conventional morphological analysis and sequencing methods. This lack of recognition may have important consequences as these A. fumigatus-related species often display some level of intrinsic resistance to azoles and other antifungal drugs. A. lentulus, A. udagawae, A. viridinutans and A. thermomutatus (Neosartorya pseudofischeri have been associated with refractory cases of IA. Microbiologists should be able to suspect the presence of these cryptic species behind a putative A. fumigatus isolate on the basis of some simple characteristics, such as defect in sporulation and/or unusual antifungal susceptibility profile. However, definitive species identification requires specific sequencing analyses of the beta-tubulin or calmodulin genes, which are not available in most laboratories. Multiplex PCR assays or matrix-assisted laser desorption ionization – time-of-flight mass spectrometry (MALDI-TOF MS gave promising results for rapid and accurate distinction between A. fumigatus and other Aspergillus spp. of the section Fumigati in clinical practice. Improved diagnostic procedures and antifungal susceptibility testing may be helpful for the early detection and management of these particular IA cases.

Species Composition, Relative Abundance and Distribution of the ...

African Journals Online (AJOL)

Species Composition, Relative Abundance and Distribution of the Avian Fauna of Entoto Natural Park and Escarpment, Addis Ababa. ... Eucalyptus plantation, soil erosion, deforestation, habitat fragmentation, settlement and land degradation were the main threats for the distribution of birds in the present study area.

Mesocosm validation of the marine No Effect Concentration of dissolved copper derived from a species sensitivity distribution.

Science.gov (United States)

Foekema, E M; Kaag, N H B M; Kramer, K J M; Long, K

2015-07-15

The Predicted No Effect Concentration (PNEC) for dissolved copper based on the species sensitivity distribution (SSD) of 24 marine single species tests was validated in marine mesocosms. To achieve this, the impact of actively maintained concentrations of dissolved copper on a marine benthic and planktonic community was studied in 18 outdoor 4.6m(3) mesocosms. Five treatment levels, ranging from 2.9 to 31μg dissolved Cu/L, were created in triplicate and maintained for 82days. Clear effects were observed on gastropod and bivalve molluscs, phytoplankton, zooplankton, sponges and sessile algae. The most sensitive biological endpoints; reproduction success of the bivalve Cerastoderma edule, copepod population development and periphyton growth were significantly affected at concentrations of 9.9μg Cu/L and higher. The No Observed Effect Concentration (NOEC) derived from this study was 5.7μg dissolved Cu/L. Taking into account the DOC concentration of the mesocosm water this NOEC is comparable to the PNEC derived from the SSD. Copyright © 2015. Published by Elsevier B.V.

Species- and age-related variation in metal exposure and accumulation of two passerine bird species

Energy Technology Data Exchange (ETDEWEB)

Berglund, A.M.M., E-mail: asa.berglund@emg.umu.se [Section of Ecology, 20014 University of Turku (Finland); Koivula, M.J.; Eeva, T. [Section of Ecology, 20014 University of Turku (Finland)

2011-10-15

We measured the concentration of several elements (arsenic [As], calcium [Ca], cadmium [Cd], copper [Cu], nickel [Ni], lead [Pb], selenium [Se] and zinc [Zn]) in adult and nestling pied flycatchers (Ficedula hypoleuca) and great tits (Parus major) at different distances to a Cu-Ni smelter in 2009. Feces of nestlings generally failed to correspond with internal element concentrations but reflected the pollution exposure, indicating an increased stress by removal of excess metals. The uptake of Cu and Ni were regulated, but As, Cd, Pb and Se accumulated in liver tissue. Pied flycatchers had generally higher element concentrations than great tits. The higher accumulation of As and Pb in pied flycatcher livers was explained by a more efficient absorption, whereas the higher Cd concentration was primarily due to different intake of food items. Age-related differences occurred between the two species, though both Cd and Se accumulated with age. - Highlights: > We measured metal concentrations in feces and livers of two passerine species. > We examined species- and age-related differences in polluted environments. > Feces was evaluated as a useful non-destructive measure of increased stress. > Generally pied flycatchers accumulated higher concentrations than great tits. > Cadmium and selenium accumulated with age in both species. - Accumulation of metals in liver of two insectivorous passerines reflects inter-specific differences in diet, absorption rate and physiological requirements.

Species- and age-related variation in metal exposure and accumulation of two passerine bird species

International Nuclear Information System (INIS)

Berglund, A.M.M.; Koivula, M.J.; Eeva, T.

2011-01-01

We measured the concentration of several elements (arsenic [As], calcium [Ca], cadmium [Cd], copper [Cu], nickel [Ni], lead [Pb], selenium [Se] and zinc [Zn]) in adult and nestling pied flycatchers (Ficedula hypoleuca) and great tits (Parus major) at different distances to a Cu-Ni smelter in 2009. Feces of nestlings generally failed to correspond with internal element concentrations but reflected the pollution exposure, indicating an increased stress by removal of excess metals. The uptake of Cu and Ni were regulated, but As, Cd, Pb and Se accumulated in liver tissue. Pied flycatchers had generally higher element concentrations than great tits. The higher accumulation of As and Pb in pied flycatcher livers was explained by a more efficient absorption, whereas the higher Cd concentration was primarily due to different intake of food items. Age-related differences occurred between the two species, though both Cd and Se accumulated with age. - Highlights: → We measured metal concentrations in feces and livers of two passerine species. → We examined species- and age-related differences in polluted environments. → Feces was evaluated as a useful non-destructive measure of increased stress. → Generally pied flycatchers accumulated higher concentrations than great tits. → Cadmium and selenium accumulated with age in both species. - Accumulation of metals in liver of two insectivorous passerines reflects inter-specific differences in diet, absorption rate and physiological requirements.

Radiation sensitivity and gene expression in Enchytraeus japonensis, a species of earth worm

International Nuclear Information System (INIS)

Kubota, Yoshihisa

2011-01-01

The importance of radiological protection of the environment based on scientific principles is gaining international recognition as environment issues garner more attention. Earthworm (annelids) is a ubiquitous soil invertebrate known to play an important role in the maintenance of the soil ecosystem and thus selected as one of 12 kinds of reference animals and plants by the ICRP. In the present study, radiation sensitivity and gene expression in a recently described terrestrial oligochaete, Enchytraeus japonensis (E. japonensis) were studied. E. japonensis worms were acutely irradiated at increasing doses of gamma radiation, and the number of worms after 30 days of radiation was examined. The dose effectively inhibiting 50% of proliferation was approximately 22 Gy, which was comparable to the dose required to elicit growth inhibition in other earthworm species. In order to seek other biological endpoints for more sensitive and/or quicker assessment of radiation effects, gene expression profiling in E. japonensis was also performed, and poly (ADP-ribose) polymerase I (PARP I) was identified as a radiation-responsive gene. PARP I transcript level increased dose-dependently. (author)

Shifts in relative stocking of common tree species in Kentucky from 1975 to 2004

Science.gov (United States)

Christopher M. Oswalt; Jeffrey A. Stringer; Jeffery A. Turner

2008-01-01

Changes in species-specific relative stocking indicate the extent to which a species is either increasing or decreasing in a particular system. Changes in relative stocking values of common tree species in Kentucky from 1988 to 2004 were compared to values calculated for 1975 to 1988. Mean annual increase in relative stocking between 1988 and 2004 was greatest for...

Different Ultimate Factors Define Timing of Breeding in Two Related Species.

Directory of Open Access Journals (Sweden)

Veli-Matti Pakanen

Full Text Available Correct reproductive timing is crucial for fitness. Breeding phenology even in similar species can differ due to different selective pressures on the timing of reproduction. These selection pressures define species' responses to warming springs. The temporal match-mismatch hypothesis suggests that timing of breeding in animals is selected to match with food availability (synchrony. Alternatively, time-dependent breeding success (the date hypothesis can result from other seasonally deteriorating ecological conditions such as intra- or interspecific competition or predation. We studied the effects of two ultimate factors on the timing of breeding, synchrony and other time-dependent factors (time-dependence, in sympatric populations of two related forest-dwelling passerine species, the great tit (Parus major and the willow tit (Poecile montanus by modelling recruitment with long-term capture-recapture data. We hypothesized that these two factors have different relevance for fitness in these species. We found that local recruitment in both species showed quadratic relationships with both time-dependence and synchrony. However, the importance of these factors was markedly different between the studied species. Caterpillar food played a predominant role in predicting the timing of breeding of the great tit. In contrast, for the willow tit time-dependence modelled as timing in relation to conspecifics was more important for local recruitment than synchrony. High caterpillar biomass experienced during the pre- and post-fledging periods increased local recruitment of both species. These contrasting results confirm that these species experience different selective pressures upon the timing of breeding, and hence responses to climate change may differ. Detailed information about life-history strategies is required to understand the effects of climate change, even in closely related taxa. The temporal match-mismatch hypothesis should be extended to consider

Impact of triphenyltin acetate in microcosms simulating floodplain lakes; II comparison of species sensitivity distributions between laboratory and semi-field

OpenAIRE

Roessink, I.; Belgers, J.D.M.; Crum, S.J.H.; Brink, van den, P.J.; Brock, T.C.M.

2006-01-01

The study objectives were to shed light on the types of freshwater organism that are sensitive to triphenyltin acetate (TPT) and to compare the laboratory and microcosm sensitivities of the invertebrate community. The responses of a wide array of freshwater taxa (including invertebrates, phytoplankton and macrophytes) from acute laboratory Single Species Tests (SST) were compared with the concentration¿response relationships of aquatic populations in two types of freshwater microcosms. Repres...

Calibration method of the pulsed X-ray relative sensitivity for ST401 plastic scintillators

International Nuclear Information System (INIS)

Xie Hongwei; Song Guzhou; Wang Kuilu

2011-01-01

The relative sensitivity calibration method of the pulsed X-ray in ST401 plastic scintillator is presented. Experimental relative sensitivity calibrations of the plastic scintillators of different thicknesses from 1 mm to 50 mm are accomplished on the 'Chenguang' pulsed X-ray source and a Co radioactive source, The uncertainty of the calibration data is evaluated, which can be treated as the experimental evidence for the relative sensitivity conversion of ST401 plastic scintillator. (authors)

An analysis of students’ cognitive structures in relation to their environmental sensitivity

Directory of Open Access Journals (Sweden)

Gercek Cem

2017-01-01

Full Text Available One of the basic aims of environment-related subjects included in the biology curriculum is to raise environmental awareness. Yet, the fact that the concepts taught especially in the context of environmental issues are abstract influences meaningful learning. This, in turn, influences behaviours displayed. Exhibiting students’ cognitive structures in assuring effective and meaningful concept teaching increases the importance of studies conducted. Unavailability of studies in the literature analysing students’ cognitive structures in relation to their sensitivity to the environment demonstrates the importance of this current study. This study aims to analyse students’ cognitive structures in relation to their environmental sensitivity. The study employs survey model- one of the qualitative research designs. The study group was composed of 56 high school students in the 2016-2017 academic year. The study group was formed through purposeful sampling. Word Association Test (WAT was prepared in order to uncover students’ cognitive structures in relation to their environmental sensitivity. Having transcribed the data obtained, they were put to content analysis and were transferred to the medium of computer. The results showed that students’ cognitive structure concerning their environmental sensitivity was divided into categories.

Sensitivity of pathogenic and free-living Leptospira spp. to UV radiation and mitomycin C

International Nuclear Information System (INIS)

Stamm, L.V.; Charon, N.W.

1988-01-01

The habitats for the two major Leptospira spp. differ. The main habitat of L. biflexa is soil and water, whereas L. interrogans primarily resides in the renal tubules of animals. We investigated whether these two species, along with L. illini (species incertae sedis), differ with respect to their sensitivity to UV radiation. The doses of UV resulting in 37, 10 and 1% survival were determined for representive serovars from each species. L. interrogans serovar pomona was 3.0 to 4.8 times more sensitive to UV than the other Leptospira species under the 37, 10, and 1% survival parameters. In comparison to other bacteria, L. interrogans serovar pomona is among the most sensitive to UV. In a qualitative UV sensitivity assay., L. interrogans serovars were found to be in general more sensitive than L. biflexa serovars. All three species were found to have a photoreactivation DNA repair mechanism. Since organisms that are resistant to UV are often resistant to the DNA cross-linking agent mitomycin C, we tested the relative sensitivity of several Leptospira serovars to this compound. With few exceptions, L. biflexa and L. illini serovars were considerably more resistant to mitomycin C than the L. interrogans serovars. The mitomycin C sensitivity assay could be a useful addition to current characterization tests used to differentiate the Leptospira species

Sensitivity of pathogenic and free-living Leptospira spp. to UV radiation and mitomycin C

Energy Technology Data Exchange (ETDEWEB)

Stamm, L.V.; Charon, N.W.

1988-03-01

The habitats for the two major Leptospira spp. differ. The main habitat of L. biflexa is soil and water, whereas L. interrogans primarily resides in the renal tubules of animals. We investigated whether these two species, along with L. illini (species incertae sedis), differ with respect to their sensitivity to UV radiation. The doses of UV resulting in 37, 10 and 1% survival were determined for representive serovars from each species. L. interrogans serovar pomona was 3.0 to 4.8 times more sensitive to UV than the other Leptospira species under the 37, 10, and 1% survival parameters. In comparison to other bacteria, L. interrogans serovar pomona is among the most sensitive to UV. In a qualitative UV sensitivity assay., L. interrogans serovars were found to be in general more sensitive than L. biflexa serovars. All three species were found to have a photoreactivation DNA repair mechanism. Since organisms that are resistant to UV are often resistant to the DNA cross-linking agent mitomycin C, we tested the relative sensitivity of several Leptospira serovars to this compound. With few exceptions, L. biflexa and L. illini serovars were considerably more resistant to mitomycin C than the L. interrogans serovars. The mitomycin C sensitivity assay could be a useful addition to current characterization tests used to differentiate the Leptospira species.

Functional-diversity indices can be driven by methodological choices and species richness.

Science.gov (United States)

Poos, Mark S; Walker, Steven C; Jackson, Donald A

2009-02-01

Functional diversity is an important concept in community ecology because it captures information on functional traits absent in measures of species diversity. One popular method of measuring functional diversity is the dendrogram-based method, FD. To calculate FD, a variety of methodological choices are required, and it has been debated about whether biological conclusions are sensitive to such choices. We studied the probability that conclusions regarding FD were sensitive, and that patterns in sensitivity were related to alpha and beta components of species richness. We developed a randomization procedure that iteratively calculated FD by assigning species into two assemblages and calculating the probability that the community with higher FD varied across methods. We found evidence of sensitivity in all five communities we examined, ranging from a probability of sensitivity of 0 (no sensitivity) to 0.976 (almost completely sensitive). Variations in these probabilities were driven by differences in alpha diversity between assemblages and not by beta diversity. Importantly, FD was most sensitive when it was most useful (i.e., when differences in alpha diversity were low). We demonstrate that trends in functional-diversity analyses can be largely driven by methodological choices or species richness, rather than functional trait information alone.

Cognitive control reduces sensitivity to relational aggression among adolescent girls.

Science.gov (United States)

Baird, Abigail A; Silver, Shari H; Veague, Heather B

2010-01-01

Relational aggression is a type of aggression that aims to hurt others through relationships and includes behaviors such as gossip and ostracism. This type of aggression is very common among adolescent girls, and in its more intense forms has been linked with poor psychosocial outcomes, including depression and suicide. In the present study we investigated whether individual differences in sensitivity to relational aggression among adolescent girls predicted recruitment of neural networks associated with executive function and cognitive control. Neural response was measured using functional magnetic resonance imaging during an affect recognition task that included unfamiliar peer faces. A finding of relatively fewer reports of being victimized by relational aggression was associated with increased recruitment of bilateral dorsolateral prefrontal cortices as well as anterior and posterior cingulate cortices in response to the affect recognition task, as well as with greater competence on behavioral measures of executive function. Our results suggest that girls who are able to recruit specific frontal networks to improve cognitive and executive control are less sensitive to relational aggression. © 2010 Psychology Press

Thermal carrying capacity for a thermally-sensitive species at the warmest edge of its range.

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Daniel Ayllón

Full Text Available Anthropogenic environmental change is causing unprecedented rates of population extirpation and altering the setting of range limits for many species. Significant population declines may occur however before any reduction in range is observed. Determining and modelling the factors driving population size and trends is consequently critical to predict trajectories of change and future extinction risk. We tracked during 12 years 51 populations of a cold-water fish species (brown trout Salmo trutta living along a temperature gradient at the warmest thermal edge of its range. We developed a carrying capacity model in which maximum population size is limited by physical habitat conditions and regulated through territoriality. We first tested whether population numbers were driven by carrying capacity dynamics and then targeted on establishing (1 the temperature thresholds beyond which population numbers switch from being physical habitat- to temperature-limited; and (2 the rate at which carrying capacity declines with temperature within limiting thermal ranges. Carrying capacity along with emergent density-dependent responses explained up to 76% of spatio-temporal density variability of juveniles and adults but only 50% of young-of-the-year's. By contrast, young-of-the-year trout were highly sensitive to thermal conditions, their performance declining with temperature at a higher rate than older life stages, and disruptions being triggered at lower temperature thresholds. Results suggest that limiting temperature effects were progressively stronger with increasing anthropogenic disturbance. There was however a critical threshold, matching the incipient thermal limit for survival, beyond which realized density was always below potential numbers irrespective of disturbance intensity. We additionally found a lower threshold, matching the thermal limit for feeding, beyond which even unaltered populations declined. We predict that most of our study

Assessing geomorphic sensitivity in relation to river capacity for adjustment

Science.gov (United States)

Reid, H. E.; Brierley, G. J.

2015-12-01

River sensitivity describes the nature and rate of channel adjustments. An approach to analysis of geomorphic river sensitivity outlined in this paper relates potential sensitivity based on the expected capacity of adjustment for a river type to the recent history of channel adjustment. This approach was trialled to assess low, moderate and high geomorphic sensitivity for four different types of river (10 reaches in total) along the Lower Tongariro River, North Island, New Zealand. Building upon the River Styles framework, river types were differentiated based upon valley setting (width and confinement), channel planform, geomorphic unit assemblages and bed material size. From this, the behavioural regime and potential for adjustment (type and extent) were determined. Historical maps and aerial photographs were geo-rectified and the channel planform digitised to assess channel adjustments for each reach from 1928 to 2007. Floodplain width controlled by terraces, exerted a strong influence upon reach scale sensitivity for the partly-confined, wandering, cobble-bed river. Although forced boundaries occur infrequently, the width of the active channel zone is constrained. An unconfined braided river reach directly downstream of the terrace-confined section was the most geomorphically sensitive reach. The channel in this reach adjusted recurrently to sediment inputs that were flushed through more confined, better connected upstream reaches. A meandering, sand-bed river in downstream reaches has exhibited negligible rates of channel migration. However, channel narrowing in this reach and the associated delta indicate that the system is approaching a threshold condition, beyond which channel avulsion is likely to occur. As this would trigger more rapid migration, this reach is considered to be more geomorphically sensitive than analysis of its low migration rate alone would indicate. This demonstrates how sensitivity is fashioned both by the behavioural regime of a reach

Relative abundance of mosquito species in Katsina Metropolis ...

African Journals Online (AJOL)

A study was conducted on the relative abundance of mosquito species, around selected areas of Katsina metropolis, Katsina State, Nigeria during the months of January, February, April and June 2010. Mosquitoes were collected from five sampling sites: Kofar Durbi, Kofar Kaura, Kofar Marusa, GRA and Layout. These were ...

Coupling ecosystems exposure to nitrogen and species sensitivity to hypoxia: modelling marine eutrophication in LCIA

DEFF Research Database (Denmark)

Cosme, Nuno Miguel Dias; Koski, Marja; Hauschild, Michael Zwicky

Characterisation modelling in Life Cycle Impact Assessment (LCIA) quantifies impacts of anthropogenic emissions by applying substance-specific impact potentials, or Characterisation Factors (CF), to the amount of substances emitted. Nitrogen (N) emissions from human activities enrich coastal marine...... ecosystems and promote planktonic growth that may lead to marine eutrophication impacts. Excessive algal biomass and dissolved oxygen (DO) depletion typify the ecosystem response to the nutrient input. The present novel method couples a mechanistic model of coastal biological processes that determines...... the ecosystem response (exposure) to anthropogenic N enrichment (eXposure Factor, XF [kgO2·kgN-1]) with the sensitivity of species exposed to oxygen-depleted waters (Effect Factor, EF [(PAF)·m3·kgO2-1], expressed as a Potentially Affected Fraction (PAF) of species). Thus, the coupled indicator (XF*EF, [(PAF)·m3...

Life history variation in Barents Sea fish: implications for sensitivity to fishing in a changing environment.

Science.gov (United States)

Wiedmann, Magnus A; Primicerio, Raul; Dolgov, Andrey; Ottesen, Camilla A M; Aschan, Michaela

2014-09-01

Under exploitation and environmental change, it is essential to assess the sensitivity and vulnerability of marine ecosystems to such stress. A species' response to stress depends on its life history. Sensitivity to harvesting is related to the life history "fast-slow" continuum, where "slow" species (i.e., large, long lived, and late maturing) are expected to be more sensitive to fishing than "fast" ones. We analyze life history traits variation for all common fish species in the Barents Sea and rank fishes along fast-slow gradients obtained by ordination analyses. In addition, we integrate species' fast-slow ranks with ecosystem survey data for the period 2004-2009, to assess life history variation at the community level in space and time. Arctic fishes were smaller, had shorter life spans, earlier maturation, larger offspring, and lower fecundity than boreal ones. Arctic fishes could thus be considered faster than the boreal species, even when body size was corrected for. Phylogenetically related species possessed similar life histories. Early in the study period, we found a strong spatial gradient, where members of fish assemblages in the southwestern Barents Sea displayed slower life histories than in the northeast. However, in later, warmer years, the gradient weakened caused by a northward movement of boreal species. As a consequence, the northeast experienced increasing proportions of slower fish species. This study is a step toward integrating life history traits in ecosystem-based areal management. On the basis of life history traits, we assess the fish sensitivity to fishing, at the species and community level. We show that climate warming promotes a borealization of fish assemblages in the northeast, associated with slower life histories in that area. The biology of Arctic species is still poorly known, and boreal species that now establish in the Arctic are fishery sensitive, which calls for cautious ecosystem management of these areas.

Genetic analysis of relative traits for a drought-sensitive mutant

International Nuclear Information System (INIS)

Gao Kangning; Wang Huaqi

2009-01-01

A drought-sensitive mutant (M616), selected from Handao 616 (HD616) by 60 Co γ-irradiation at 200Gy, was used. Some morphological and yield related traits of M166 and HD616 related to drought resistance were investigated. We further developed F 1 and F 2 reciprocal hybrid combinations derived from the crosses between M616 and HD616, between M616 and IRAT109, respectively, and genetic analysis of 3 traits including plant height, culm width of main stem and seed setting rate on main panicle were camed out. The results showed that M616 showed obviously sensitive to drought stress. Analysis of variance for three traits in upland and paddy between F 1 reciprocal hybrid combinations showed that each trait had no significant difference, and indicated that there were no differences of cytoplasmic hereditary effect. In addition, 3 traits of F 2 populations, were found that the frequency distributions of culm width showed normal distribution, indicating that culm width was polygenic trait, and the frequency distribution of plant height and seed setting rate did not show normal distribution, indicating that the two traits were qualitative-quantitative traits. Genetic analysis of relative traits for a drought-sensitive mutant of upland rice was a basic work for the gene location and cloning. (authors)

Chemical review and studies related to species from the genus Tynanthus (Bignoniaceae

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Fernanda Colombi Cansian

2015-09-01

Full Text Available Species from the Bignoniaceae Family, including the genus Tynanthus, are very prevalent in the tropical Americas, with specimens found in a large part of the Brazilian territory. These plants are commonly used in traditional medicine for several purposes, and some studies have described their chemical structure, in addition to other reports related to some species from this genus. This review aimed to gather information from published works concerning species of the genus Tynanthus, as well as to detect flaws in research related to these plants, which may have great biological and pharmaceutical importance. Also, this review points out some common chemical characteristics of these species, providing information that may help new researchers to improve their knowledge about these plants.

Leaf injury characteristics of grassland species exposed to ozone in relation to soil moisture condition and vapour pressure deficit

International Nuclear Information System (INIS)

Bungener, P.; Balls, G.R.; Nussbaum, S.; Geissmann, M.; Grub, A.; Fuhrer, J.

1999-01-01

A range of plant species typical of semi-natural grasslands were tested for their sensitivity to short-term ozone injury under normal and reduced irrigation, and in relationship to air vapour pressure deficit. Potted specimens of 24 herbs, legumes and grasses were exposed during two seasons to four O 3 treatments in open-top chambers. The ozone treatments were: (a) charcoal-filtered air; (b) charcoal-filtered air plus ozone to match ambient levels; (c) charcoal-filtered air plus O 3 to ambient levels 1.5 and (d) charcoal-filtered air with ozone added to twice ambient levels during selected episodes of 7–13 d. During these ozone episodes, half of the plants in each ozone treatment received reduced irrigation (dry treatment) while the rest was kept under full irrigation (wet treatment). Type and date of first occurrence of leaf injury were noted during individual growth periods. Plants were harvested three times per year, and the percentage of injured leaves was recorded. Depending on species, injury symptoms were expressed as flecking (O 3 -specific injury), leaf yellowing or anthocyanin formation. Carum carvi and most species of the Fabaceae family (Onobrychis sativa, Trifolium repens, Trifolium pratense) were found to be most responsive to O 3 , injury occurring after only a few days of exposure in treatment (b). An episodic reduction in irrigation tended to reduce the expression of O 3 -specific symptoms, but only in species for which a reduction in soil moisture potential and an associated reduction in stomatal conductance during the dry episodes were observed. In other species, the protection from O 3 injury seemed to be of little importance. Using artificial neural networks the injury response of nine species was analysed in relation to Species, stomatal conductance, ozone as AOT40 (accumulated exposure above a threshold of 0.04 ppm for periods with global radiation ≥ 50 W m −2 (Fuhrer et al., 1997)), mean relative growth rate, air vapour pressure

A novel multiplex PCR discriminates Bacillus anthracis and its genetically related strains from other Bacillus cereus group species.

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Hirohito Ogawa

Full Text Available Anthrax is an important zoonotic disease worldwide that is caused by Bacillus anthracis, a spore-forming pathogenic bacterium. A rapid and sensitive method to detect B. anthracis is important for anthrax risk management and control in animal cases to address public health issues. However, it has recently become difficult to identify B. anthracis by using previously reported molecular-based methods because of the emergence of B. cereus, which causes severe extra-intestinal infection, as well as the human pathogenic B. thuringiensis, both of which are genetically related to B. anthracis. The close genetic relation of chromosomal backgrounds has led to complexity of molecular-based diagnosis. In this study, we established a B. anthracis multiplex PCR that can screen for the presence of B. anthracis virulent plasmids and differentiate B. anthracis and its genetically related strains from other B. cereus group species. Six sets of primers targeting a chromosome of B. anthracis and B. anthracis-like strains, two virulent plasmids, pXO1 and pXO2, a bacterial gene, 16S rRNA gene, and a mammalian gene, actin-beta gene, were designed. The multiplex PCR detected approximately 3.0 CFU of B. anthracis DNA per PCR reaction and was sensitive to B. anthracis. The internal control primers also detected all bacterial and mammalian DNAs examined, indicating the practical applicability of this assay as it enables monitoring of appropriate amplification. The assay was also applied for detection of clinical strains genetically related to B. anthracis, which were B. cereus strains isolated from outbreaks of hospital infections in Japan, and field strains isolated in Zambia, and the assay differentiated B. anthracis and its genetically related strains from other B. cereus group strains. Taken together, the results indicate that the newly developed multiplex PCR is a sensitive and practical method for detecting B. anthracis.

Is Apis mellifera more sensitive to insecticides than other insects?

Science.gov (United States)

Hardstone, Melissa C; Scott, Jeffrey G

2010-11-01

Honey bees (Apis mellifera L.) are among the most important pollinators in natural and agricultural settings. They commonly encounter insecticides, and the effects of insecticides on honey bees have been frequently noted. It has been suggested that honey bees may be (as a species) uniquely sensitive to insecticides, although no comparative toxicology study has been undertaken to examine this claim. An extensive literature review was conducted, using data in which adult insects were topically treated with insecticides. The goal of this review was to summarize insecticide toxicity data between A. mellifera and other insects to determine the relative sensitivity of honey bees to insecticides. It was found that, in general, honey bees were no more sensitive than other insect species across the 62 insecticides examined. In addition, honey bees were not more sensitive to any of the six classes of insecticides (carbamates, nicotinoids, organochlorines, organophosphates, pyrethroids and miscellaneous) examined. While honey bees can be sensitive to individual insecticides, they are not a highly sensitive species to insecticides overall, or even to specific classes of insecticides. However, all pesticides should be used in a way that minimizes honey bee exposure, so as to minimize possible declines in the number of bees and/or honey contamination. Copyright © 2010 Society of Chemical Industry.

Malaria in Africa: vector species' niche models and relative risk maps.

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Alexander Moffett

2007-09-01

Full Text Available A central theoretical goal of epidemiology is the construction of spatial models of disease prevalence and risk, including maps for the potential spread of infectious disease. We provide three continent-wide maps representing the relative risk of malaria in Africa based on ecological niche models of vector species and risk analysis at a spatial resolution of 1 arc-minute (9 185 275 cells of approximately 4 sq km. Using a maximum entropy method we construct niche models for 10 malaria vector species based on species occurrence records since 1980, 19 climatic variables, altitude, and land cover data (in 14 classes. For seven vectors (Anopheles coustani, A. funestus, A. melas, A. merus, A. moucheti, A. nili, and A. paludis these are the first published niche models. We predict that Central Africa has poor habitat for both A. arabiensis and A. gambiae, and that A. quadriannulatus and A. arabiensis have restricted habitats in Southern Africa as claimed by field experts in criticism of previous models. The results of the niche models are incorporated into three relative risk models which assume different ecological interactions between vector species. The "additive" model assumes no interaction; the "minimax" model assumes maximum relative risk due to any vector in a cell; and the "competitive exclusion" model assumes the relative risk that arises from the most suitable vector for a cell. All models include variable anthrophilicity of vectors and spatial variation in human population density. Relative risk maps are produced from these models. All models predict that human population density is the critical factor determining malaria risk. Our method of constructing relative risk maps is equally general. We discuss the limits of the relative risk maps reported here, and the additional data that are required for their improvement. The protocol developed here can be used for any other vector-borne disease.

PCR amplification of repetitive sequences as a possible approach in relative species quantification

DEFF Research Database (Denmark)

Ballin, Nicolai Zederkopff; Vogensen, Finn Kvist; Karlsson, Anders H

2012-01-01

Abstract Both relative and absolute quantifications are possible in species quantification when single copy genomic DNA is used. However, amplification of single copy genomic DNA does not allow a limit of detection as low as one obtained from amplification of repetitive sequences. Amplification...... of repetitive sequences is therefore frequently used in absolute quantification but problems occur in relative quantification as the number of repetitive sequences is unknown. A promising approach was developed where data from amplification of repetitive sequences were used in relative quantification of species...... to relatively quantify the amount of chicken DNA in a binary mixture of chicken DNA and pig DNA. However, the designed PCR primers lack the specificity required for regulatory species control....

Anxiety Sensitivity and Sleep-Related Problems in Anxious Youth

Science.gov (United States)

Weiner, Courtney L.; Elkins, Meredith; Pincus, Donna; Comer, Jonathan

2015-01-01

Anxiety disorders constitute the most common mental health disturbance experienced by youth. Sleep-related problems (SRPs) are highly prevalent among anxious youth and encompass a variety of problems including nighttime fears, insomnia, and refusal to sleep alone. Given that chronic sleep disturbance is associated with a range of behavioral and physical problems in youth and predicts future psychopathology, it is important to elucidate the nature of SRPs in anxious youth. The present study investigated the relationship between sleep problems and anxiety sensitivity in a sample of 101 anxious youth, ages 6–17. Heightened anxiety sensitivity significantly predicted prolonged sleep onset latency across the sample, even after accounting for severity of anxiety, depression, and age. Results support previous research indicating that SRPs are common among anxious youth and suggest that anxiety sensitivity may play a particularly important role in sleep onset latency. PMID:25863826

Relative tolerance of a range of Australian native plant species and lettuce to copper, zinc, cadmium, and lead.

Science.gov (United States)

Lamb, Dane T; Ming, Hui; Megharaj, Mallavarapu; Naidu, Ravi

2010-10-01

The tolerance of wild flora to heavy-metal exposure has received very little research. In this study, the tolerance of four native tree species, four native grass species, and lettuce to copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb) was investigated in a root-elongation study using Petri dishes. The results of these studies show a diverse range of responses to Cu, Zn, Cd, and Pb amongst the tested plant species. Toxicity among metals decreased in the following order: Cd ~ Cu > Pb > Zn. Metal concentrations resulting in a 50% reduction in growth (EC(50)) varied considerably, ranging from (microM) 30 (Dichanthium sericeum) to >2000 (Acacia spp.) for Cu; from 260 (Lactuca sativa) to 2000 (Acacia spp.) for Zn; from 27 (L. sativa) to 940 (Acacia holosericea) for Cd; and from 180 (L. sativa) to >1000 (Acacia spp.) for Pb. Sensitive native plant species identified included D. sericeum, Casuarina cunninghamiana, and Austrodanthonia caespitosa. However, L. sativa (lettuce) was also among the most sensitive to all four metals. Acacia species showed a high tolerance to metal exposure, suggesting that the Acacia genus shows potential for use in contaminated-site revegetation.

Improving transcriptome de novo assembly by using a reference genome of a related species: Translational genomics from oil palm to coconut.

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Alix Armero

Full Text Available The palms are a family of tropical origin and one of the main constituents of the ecosystems of these regions around the world. The two main species of palm represent different challenges: coconut (Cocos nucifera L. is a source of multiple goods and services in tropical communities, while oil palm (Elaeis guineensis Jacq is the main protagonist of the oil market. In this study, we present a workflow that exploits the comparative genomics between a target species (coconut and a reference species (oil palm to improve the transcriptomic data, providing a proteome useful to answer functional or evolutionary questions. This workflow reduces redundancy and fragmentation, two inherent problems of transcriptomic data, while preserving the functional representation of the target species. Our approach was validated in Arabidopsis thaliana using Arabidopsis lyrata and Capsella rubella as references species. This analysis showed the high sensitivity and specificity of our strategy, relatively independent of the reference proteome. The workflow increased the length of proteins products in A. thaliana by 13%, allowing, often, to recover 100% of the protein sequence length. In addition redundancy was reduced by a factor greater than 3. In coconut, the approach generated 29,366 proteins, 1,246 of these proteins deriving from new contigs obtained with the BRANCH software. The coconut proteome presented a functional profile similar to that observed in rice and an important number of metabolic pathways related to secondary metabolism. The new sequences found with BRANCH software were enriched in functions related to biotic stress. Our strategy can be used as a complementary step to de novo transcriptome assembly to get a representative proteome of a target species. The results of the current analysis are available on the website PalmComparomics (http://palm-comparomics.southgreen.fr/.

Improving transcriptome de novo assembly by using a reference genome of a related species: Translational genomics from oil palm to coconut.

Science.gov (United States)

Armero, Alix; Baudouin, Luc; Bocs, Stéphanie; This, Dominique

2017-01-01

The palms are a family of tropical origin and one of the main constituents of the ecosystems of these regions around the world. The two main species of palm represent different challenges: coconut (Cocos nucifera L.) is a source of multiple goods and services in tropical communities, while oil palm (Elaeis guineensis Jacq) is the main protagonist of the oil market. In this study, we present a workflow that exploits the comparative genomics between a target species (coconut) and a reference species (oil palm) to improve the transcriptomic data, providing a proteome useful to answer functional or evolutionary questions. This workflow reduces redundancy and fragmentation, two inherent problems of transcriptomic data, while preserving the functional representation of the target species. Our approach was validated in Arabidopsis thaliana using Arabidopsis lyrata and Capsella rubella as references species. This analysis showed the high sensitivity and specificity of our strategy, relatively independent of the reference proteome. The workflow increased the length of proteins products in A. thaliana by 13%, allowing, often, to recover 100% of the protein sequence length. In addition redundancy was reduced by a factor greater than 3. In coconut, the approach generated 29,366 proteins, 1,246 of these proteins deriving from new contigs obtained with the BRANCH software. The coconut proteome presented a functional profile similar to that observed in rice and an important number of metabolic pathways related to secondary metabolism. The new sequences found with BRANCH software were enriched in functions related to biotic stress. Our strategy can be used as a complementary step to de novo transcriptome assembly to get a representative proteome of a target species. The results of the current analysis are available on the website PalmComparomics (http://palm-comparomics.southgreen.fr/).

Differential Privacy for Relational Algebra: Improving the Sensitivity Bounds via Constraint Systems

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Catuscia Palamidessi

2012-07-01

Full Text Available Differential privacy is a modern approach in privacy-preserving data analysis to control the amount of information that can be inferred about an individual by querying a database. The most common techniques are based on the introduction of probabilistic noise, often defined as a Laplacian parametric on the sensitivity of the query. In order to maximize the utility of the query, it is crucial to estimate the sensitivity as precisely as possible. In this paper we consider relational algebra, the classical language for queries in relational databases, and we propose a method for computing a bound on the sensitivity of queries in an intuitive and compositional way. We use constraint-based techniques to accumulate the information on the possible values for attributes provided by the various components of the query, thus making it possible to compute tight bounds on the sensitivity.

Early sensitivity of left perisylvian cortex to relationality in nouns and verbs.

Science.gov (United States)

Williams, Adina; Reddigari, Samir; Pylkkänen, Liina

2017-06-01

The ability to track the relationality of concepts, i.e., their capacity to encode a relationship between entities, is one of the core semantic abilities humans possess. In language processing, we systematically leverage this ability when computing verbal argument structure, in order to link participants to the events they participate in. Previous work has converged on a large region of left posterior perisylvian cortex as a locus for such processing, but the wide range of experimental stimuli and manipulations has yielded an unclear picture of the region's exact role(s). Importantly, there is a tendency for effects of relationality in single-word studies to localize to posterior temporo-parietal cortex, while argument structure effects in sentences appear in left superior temporal cortex. To characterize these sensitivities, we designed two MEG experiments that cross the factors relationality and eventivity. The first used minimal noun phrases and tested for an effect of semantic composition, while the second employed full sentences and a manipulation of grammatical category. The former identified a region of the left inferior parietal lobe sensitive to relationality, but not eventivity or combination, beginning at 170ms. The latter revealed a similarly-timed effect of relationality in left mid-superior temporal cortex, independent of eventivity and category. The results suggest that i) multiple sub-regions of perisylvian cortex are sensitive to the relationality carried by concepts even in the absence of arguments, ii) linguistic context modulates the locus of this sensitivity, consistent with prior studies, and iii) relationality information is accessed early - before 200ms - regardless of the concept's event status or syntactic category. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ward identities and consistency relations for the large scale structure with multiple species

International Nuclear Information System (INIS)

Peloso, Marco; Pietroni, Massimo

2014-01-01

We present fully nonlinear consistency relations for the squeezed bispectrum of Large Scale Structure. These relations hold when the matter component of the Universe is composed of one or more species, and generalize those obtained in [1,2] in the single species case. The multi-species relations apply to the standard dark matter + baryons scenario, as well as to the case in which some of the fields are auxiliary quantities describing a particular population, such as dark matter halos or a specific galaxy class. If a large scale velocity bias exists between the different populations new terms appear in the consistency relations with respect to the single species case. As an illustration, we discuss two physical cases in which such a velocity bias can exist: (1) a new long range scalar force in the dark matter sector (resulting in a violation of the equivalence principle in the dark matter-baryon system), and (2) the distribution of dark matter halos relative to that of the underlying dark matter field

Novel intron markers to study the phylogeny of closely related mammalian species

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Castresana Jose

2010-11-01

Full Text Available Abstract Background Multilocus phylogenies can be used to infer the species tree of a group of closely related species. In species trees, the nodes represent the actual separation between species, thus providing essential information about their evolutionary history. In addition, multilocus phylogenies can help in analyses of species delimitation, gene flow and genetic differentiation within species. However, few adequate markers are available for such studies. Results In order to develop nuclear markers that can be useful in multilocus studies of mammals, we analyzed the mammalian genomes of human, chimpanzee, macaque, dog and cow. Rodents were excluded due to their unusual genomic features. Introns were extracted from the mammalian genomes because of their greater genetic variability and ease of amplification from the flanking exons. To an initial set of more than 10,000 one-to-one orthologous introns we applied several filters to select introns that belong to single-copy genes, show neutral evolutionary rates and have an adequate length for their amplification. This analysis led to a final list of 224 intron markers randomly distributed along the genome. To experimentally test their validity, we amplified twelve of these introns in a panel of six mammalian species. The result was that seven of these introns gave rise to a PCR band of the expected size in all species. In addition, we sequenced these bands and analyzed the accumulation of substitutions in these introns in five pairs of closely related species. The results showed that the estimated genetic distances in the five species pairs was quite variable among introns and that this divergence cannot be directly predicted from the overall intron divergence in mammals. Conclusions We have designed a new set of 224 nuclear introns with optimal features for the phylogeny of closely related mammalian species. A large proportion of the introns tested experimentally showed a perfect amplification

Correlated evolution of short wavelength sensitive photoreceptor sensitivity and color pattern in Lake Malawi cichlids

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Michael J. Pauers

2016-02-01

Full Text Available For evolutionary ecologists, the holy grail of visual ecology is to establish an unambiguous link between photoreceptor sensitivity, the spectral environment, and the perception of specific visual stimuli (e.g., mates, food, predators, etc.. Due to the bright nuptial colors of the males, and the role female mate choice plays in their evolution, the haplochromine cichlid fishes of the African great lakes are favorite research subjects for such investigations. Despite this attention, current evidence is equivocal; while distinct correlations among photoreceptor sensitivity, photic environment, and male coloration exist in Lake Victorian haplochromines, attempts to find such correlations in Lake Malawian cichlids have failed. Lake Malawi haplochromines have a wide variability in their short-wavelength-sensitive photoreceptors, especially compared to their mid- and long-wavelength-sensitive photoreceptors; these cichlids also vary in the degree to which they express one of three basic color patterns (vertical bars, horizontal stripes, and solid patches of colors, each of which is likely used in a different form of communication. Thus, we hypothesize that, in these fishes, spectral sensitivity and color pattern have evolved in a correlated fashion to maximize visual communication; specifically, ultraviolet sensitivity should be found in vertically-barred species to promote ‘private’ communication, while striped species should be less likely to have ultraviolet sensitivity, since their color pattern carries ‘public’ information. Using phylogenetic independent contrasts, we found that barred species had strong sensitivity to ultraviolet wavelengths, but that striped species typically lacked sensitivity to ultraviolet light. Further, the only variable, even when environmental variables were simultaneously considered, that could predict ultraviolet sensitivity was color pattern. We also found that, using models of correlated evolution, color

Microcosm investigations of stormwater pond sediment toxicity to embryonic and larval amphibians: Variation in sensitivity among species

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Snodgrass, Joel W. [Department of Biological Sciences, Towson University, 8000 York Road, Towson, MD 21252 (United States)], E-mail: jsnodgrass@towson.edu; Casey, Ryan E. [Department of Chemistry, Towson University, 8000 York Road, Towson, MD 21252 (United States); Joseph, Debra; Simon, Judith A. [Department of Biological Sciences, Towson University, 8000 York Road, Towson, MD 21252 (United States)

2008-07-15

Stormwater ponds have become common features of modern development and often represent significant amounts of open space in urbanized areas. Although stormwater ponds may provide habitat for wildlife, factors responsible for producing variation in wildlife use of ponds have received limited attention. To investigate the role of variation in species tolerances of pollutants in structuring pond-breeding amphibian assemblages, we exposed species tolerant (Bufo americanus) and not tolerant (Rana sylvatica) of urbanization to pond sediments in laboratory microcosms. Pond microcosms had elevated sediment metal levels and chloride water concentrations. Among R. sylvatica embryos, exposure to pond sediments resulted in 100% mortality. In contrast, B. americanus embryos and larvae experienced only sublethal effects (i.e., reduced size at metamorphosis) due to pond sediment exposure. Our results suggest variation in pollutant tolerance among early developmental stages of amphibians may act in concert with terrestrial habitat availability to structure amphibian assemblages associated with stormwater ponds. - Variation among species in sensitivity to pollutants can influence stormwater pond amphibian assemblages.

Long-term monitoring reveals an avian species credit in secondary forest patches of Costa Rica

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Steven C. Latta

2017-06-01

Full Text Available Degraded and secondary forests comprise approximately 50% of remaining tropical forest. Bird community characteristics and population trends in secondary forests are infrequently studied, but secondary forest may serve as a “safety net” for tropical biodiversity. Less understood is the occurrence of time-delayed, community-level dynamics such as an extinction debt of specialist species or a species credit resulting from the recolonization of forest patches by extirpated species. We sought to elucidate patterns and magnitudes of temporal change in avian communities in secondary forest patches in Southern Costa Rica biannually over a 10 year period during the late breeding season and mid-winter. We classified birds caught in mist nets or recorded in point counts by residency status, and further grouped them based on preferred habitat, sensitivity to disturbance, conservation priority, foraging guild, and foraging strata. Using hierarchical, mixed-effects models we tested for trends among species that share traits. We found that permanent-resident species increased over time relative to migrants. In both seasons, primary forest species generally increased while species typical of secondary forest, scrub, or edge declined. Species relatively sensitive to habitat disturbance increased significantly over time, whereas birds less sensitive to disturbance decreased. Similarly, generalists with higher habitat breadth scores declined. Because, we found very few changes in vegetation characteristics in secondary forest patches, shifts in the avian community toward primary forest species represent a species credit and are likely related to vegetation changes in the broader landscape. We suggest that natural regeneration and maturation of secondary forests should be recognized as a positive conservation development of potential benefit even to species typical of primary forest.

Differentiation of water-related traits in terrestrial and epiphytic Cymbidium species

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Shi-Bao eZhang

2015-04-01

Full Text Available Epiphytes that grow in the canopies of tropical and subtropical forests experience different water regimes when compared with terrestrial plants. However, the differences in adaptive strategies between epiphytic and terrestrial plants with respect to plant water relations remain poorly understood. To understand how water-related traits contrast between epiphytic and terrestrial growth forms within the Cymbidium (Orchidaceae, we assessed leaf anatomy, hydraulics, and physiology of seven terrestrial and 13 epiphytic species using a common garden experiment. Compared with terrestrial species, epiphytic species had higher values for leaf mass per unit area (LMA, leaf thickness (LT, epidermal thickness, saturated water content (SWC and the time required to dry saturated leaves to 70% relative water content (T70. However, vein density (Dvein, stomatal density (SD, and photosynthetic capacity (Amax did not differ significantly between the two forms. T70 was positively correlated with LT, LMA, and SWC, and negatively correlated with stomatal index (SI. Amax showed positive correlations with SD and SI, but not with Dvein. Vein density was marginally correlated with SD, and significantly correlated with SI. Overall, epiphytic orchids exhibited substantial ecophysiological differentiations from terrestrial species, with the former type showing trait values indicative of greater drought tolerance and increased water storage capacity. The ability to retain water in the leaves plays a key role in maintaining a water balance in those epiphytes. Therefore, the process of transpiration depends less upon the current substrate water supply and enables epiphytic Cymbidium species to adapt more easily to canopy habitats.

Use of Recombinant Antigens for Sensitive Serodiagnosis of American Tegumentary Leishmaniasis Caused by Different Leishmania Species.

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Sato, Camila Massae; Sanchez, Maria Carmen Arroyo; Celeste, Beatriz Julieta; Duthie, Malcolm S; Guderian, Jeffrey; Reed, Steven G; de Brito, Maria Edileuza Felinto; Campos, Marliane Batista; de Souza Encarnação, Helia Valeria; Guerra, Jorge; de Mesquita, Tirza Gabrielle Ramos; Pinheiro, Suzana Kanawati; Ramasawmy, Rajendranath; Silveira, Fernando Tobias; de Assis Souza, Marina; Goto, Hiro

2017-02-01

American tegumentary leishmaniasis (ATL) (also known as cutaneous leishmaniasis [CL]) is caused by various species of protozoa of the genus Leishmania The diagnosis is achieved on a clinical, epidemiological, and pathological basis, supported by positive parasitological exams and demonstration of leishmanin delayed-type hypersensitivity. Serological assays are not routinely used in the diagnosis because many are considered to have low sensitivity and the particular Leishmania species causing the disease can lead to variable performance. In the present study, we generated recombinant versions of two highly conserved Leishmania proteins, Leishmania (Viannia) braziliensis-derived Lb8E and Lb6H, and evaluated both in enzyme-linked immunosorbent assays (ELISA). Recombinant Lb6H (rLb6H) had better performance and reacted with 100.0% of the ATL and 89.4% of the VL samples. These reactions with rLb6H were highly specific (98.5%) when compared against those for samples from healthy control individuals. We then assessed rLb6H against sera from ATL patients infected with different species of Leishmania prevalent in Brazil [Leishmania (Leishmania) amazonensis, L (Viannia) braziliensis, and L (V) guyanensis] and samples from patients with other infectious diseases. In analyses of 500 sera, ELISA using rLb6H detected all 219 ATL samples (sensitivity of 100.0%) with an overall specificity of 93.9% (considering healthy individuals and other infectious diseases patients). Only a minority of samples from Chagas disease patients possessed antibodies against rLb6H, and all of these responses were low (with a highest reactivity index of 2.2). Taken together, our data support further evaluation of rLb6H and the potential for its routine use in the serological diagnosis of ATL. Copyright © 2017 Sato et al.

Screening the Drug Sensitivity Genes Related to GEM and CDDP in the Lung Cancer Cell-lines

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Chunyu YANG

2009-10-01

Full Text Available Background and objective Screening of small-cell lung cancer (SCLC and non-small cell lung cancer (NSCLC cell lines with gemcitabine hydrochloride (GEM and cisplatin (CDDP related to drug sensitivity gene might clarify the action mechanism of anti-cancer drugs and provide a new clue for overcoming drug resistance and the development of new anti-cancer drugs, and also provide theoretical basis for the clinical treatment of individual. Methods The drug sensitivity of CDDP and GEM in 4 SCLC cell lines and 6 NSCLC cell lines was determined using MTT colorimetric assay, while the cDNA macroarray was applied to detect the gene expression state related to drug sensitivity of 10 lung cancer cell line in 1 291, and the correlation between the two was analysized. Results There were 6 genes showing significant positive correlation (r≥0.632, P < 0.05 with GEM sensitivity; 45 genes positively related to CDDP; another 41 genes related to both GEM and CDDP (r≥± 0.4. Lung cancer with GEM and CDDP sensitivity of two types of drugs significantly related genes were Metallothinein (Signal transduction molecules, Cathepsin B (Organization protease B and TIMP1 (Growth factor; the GEM, CDDP sensitivity associated genes of lung cancer cell lines mainly distributed in Metallothinein, Cathepsin B, growth factor TIMP1 categories. Conclusion There existed drug-related sensitive genes of GEM, CDDP in SCLC and NSCLC cell lines; of these genes, Metallothinein, Cathepsin B and TIMP1 genes presented a significant positive correlation with GEM drug sensitivity, a significant negative correlation with CDDP drug sensitivity.

Standardization of a two-step real-time polymerase chain reaction based method for species-specific detection of medically important Aspergillus species.

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Das, P; Pandey, P; Harishankar, A; Chandy, M; Bhattacharya, S; Chakrabarti, A

2017-01-01

Standardization of Aspergillus polymerase chain reaction (PCR) poses two technical challenges (a) standardization of DNA extraction, (b) optimization of PCR against various medically important Aspergillus species. Many cases of aspergillosis go undiagnosed because of relative insensitivity of conventional diagnostic methods such as microscopy, culture or antigen detection. The present study is an attempt to standardize real-time PCR assay for rapid sensitive and specific detection of Aspergillus DNA in EDTA whole blood. Three nucleic acid extraction protocols were compared and a two-step real-time PCR assay was developed and validated following the recommendations of the European Aspergillus PCR Initiative in our setup. In the first PCR step (pan-Aspergillus PCR), the target was 28S rDNA gene, whereas in the second step, species specific PCR the targets were beta-tubulin (for Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus), gene and calmodulin gene (for Aspergillus niger). Species specific identification of four medically important Aspergillus species, namely, A. fumigatus, A. flavus, A. niger and A. terreus were achieved by this PCR. Specificity of the PCR was tested against 34 different DNA source including bacteria, virus, yeast, other Aspergillus sp., other fungal species and for human DNA and had no false-positive reactions. The analytical sensitivity of the PCR was found to be 102 CFU/ml. The present protocol of two-step real-time PCR assays for genus- and species-specific identification for commonly isolated species in whole blood for diagnosis of invasive Aspergillus infections offers a rapid, sensitive and specific assay option and requires clinical validation at multiple centers.

A simple, versatile and sensitive cell-based assay for prions from various species.

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Zaira E Arellano-Anaya

Full Text Available Detection and quantification of prion infectivity is a crucial step for various fundamental and applied aspects of prion research. Identification of cell lines highly sensitive to prion infection led to the development of cell-based titration procedures aiming at replacing animal bioassays, usually performed in mice or hamsters. However, most of these cell lines are only permissive to mouse-adapted prions strains and do not allow titration of prions from other species. In this study, we show that epithelial RK13, a cell line permissive to mouse and bank vole prion strains and to natural prion agents from sheep and cervids, enables a robust and sensitive detection of mouse and ovine-derived prions. Importantly, the cell culture work is strongly reduced as the RK13 cell assay procedure designed here does not require subcultivation of the inoculated cultures. We also show that prions effectively bind to culture plastic vessel and are quantitatively detected by the cell assay. The possibility to easily quantify a wider range of prions, including rodent experimental strains but also natural agents from sheep and cervids, should prompt the spread of cell assays for routine prion titration and lead to valuable information in fundamental and applied studies.

A further investigation of the relations of anxiety sensitivity to smoking motives.

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Battista, Susan R; Stewart, Sherry H; Fulton, Heather G; Steeves, Dan; Darredeau, Christine; Gavric, Dubravka

2008-11-01

Prior research has shown that anxiety sensitivity (AS) is associated with smoking to reduce negative affect (e.g., [Comeau, N., Stewart, S.H., & Loba, P., (2001). The relations of trait anxiety, anxiety sensitivity and sensation seeking to adolescents' motivations for alcohol, cigarette, and marijuana use. Addictive Behaviors, 26, 803-825.]). However, given limitations in the measurement of smoking motives in previous AS studies, it has yet to be definitively established that AS is specifically related to negative reinforcement smoking motives. Moreover, the overall AS construct is comprised of three lower-order components: physical, psychological, and social concerns (e.g., [Stewart, S.H., Taylor, S., & Baker, J.M., (1997). Gender differences in dimensions of anxiety sensitivity. Journal of Anxiety Disorders, 11, 179-200.]). Previous investigations generally have not examined the relative contributions of each of these three AS components to smoking for negative reinforcement motives. The present study attempted to address each of these gaps in the literature. A sample of 119 smokers attending a tobacco intervention program (see [Mullane, J.C., Stewart, S.H., Rhyno, E., Steeves, D., Watt, M., & Eisner, A., (2008). Anxiety sensitivity and difficulties with smoking cessation. In A.M. Columbus (Ed.), Advances in Psychological Research (vol. 54A, pp. 141-155). Hauppauge, NY: Nova Science Publishers.]) completed the Anxiety Sensitivity Index (ASI; [Peterson, R.A., & Reiss, S., (1992). The Anxiety Sensitivity Index manual (2nd ed.). Worthington, OH: International Diagnostic Services.]) and the Reasons For Smoking scale (RFS; [Ikard, F.F., Green, D.E., & Horn, D., (1969). A scale to differentiate between types of smoking as related to the management of affect. International Journal of the Addictions, 4, 649-659.]) at pre-treatment. In a principal components analysis (PCA) of the RFS items, stringent parallel analysis supported a two-factor solution (negative and positive

Comparative analysis for the measured and the predicted relative sensitivity of rhodium In core detector

International Nuclear Information System (INIS)

Moon, Sang Rae; Cha, Kyoon Ho; Bae, Seong Man

2012-01-01

Self-powered neutron detector (SPND) is widely used as in-core flux monitoring in nuclear power plants. OPR1000 has applied a rhodium (Rh) as the emitter of the SPND. The SPND contains a neutron-sensitive metallic emitter surrounded by a ceramic insulator. When capturing a neutron, the Rh will be decayed by emitting some electrons which is crossing the sheath and produce current. This current can be measured externally using pico-ammeter. The sensitivity of detectors is closely related with the geometry and material of the detectors. The lifetime of in-core detector is determined by calculating the relative sensitivity of Rh detector. It is required that the Rh detector should be replaced before the burn-up of Rh detector has reached 66% of its original compositions. To predict Rh detector's relative sensitivity ANC code, advanced nodal code capable of two-dimensional and three-dimensional calculations, is used. It is determined that the Rh detectors should be replaced on the basis of the predicted sensitivity value calculated by ANC code. When evaluating the life of Rh detectors using ANC code, it is assumed that the uncertainty of the sensitivity calculation include the measurement error of 5%. As a result of the analysis of measured and predicted data for the Rh detector's relative sensitivity, it is possible to reduce the assumed uncertainty

Comparative analysis for the measured and the predicted relative sensitivity of rhodium In core detector

Energy Technology Data Exchange (ETDEWEB)

Moon, Sang Rae; Cha, Kyoon Ho; Bae, Seong Man [Nuclear Reactor Safety Lab., KHNP Central Research Institute, Daejeon (Korea, Republic of)

2012-10-15

Self-powered neutron detector (SPND) is widely used as in-core flux monitoring in nuclear power plants. OPR1000 has applied a rhodium (Rh) as the emitter of the SPND. The SPND contains a neutron-sensitive metallic emitter surrounded by a ceramic insulator. When capturing a neutron, the Rh will be decayed by emitting some electrons which is crossing the sheath and produce current. This current can be measured externally using pico-ammeter. The sensitivity of detectors is closely related with the geometry and material of the detectors. The lifetime of in-core detector is determined by calculating the relative sensitivity of Rh detector. It is required that the Rh detector should be replaced before the burn-up of Rh detector has reached 66% of its original compositions. To predict Rh detector's relative sensitivity ANC code, advanced nodal code capable of two-dimensional and three-dimensional calculations, is used. It is determined that the Rh detectors should be replaced on the basis of the predicted sensitivity value calculated by ANC code. When evaluating the life of Rh detectors using ANC code, it is assumed that the uncertainty of the sensitivity calculation include the measurement error of 5%. As a result of the analysis of measured and predicted data for the Rh detector's relative sensitivity, it is possible to reduce the assumed uncertainty.

Coupling Satellite Data with Species Distribution and Connectivity Models as a Tool for Environmental Management and Planning in Matrix-Sensitive Species

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Rödder, Dennis; Nekum, Sven; Cord, Anna F.; Engler, Jan O.

2016-07-01

Climate change and anthropogenic habitat fragmentation are considered major threats for global biodiversity. As a direct consequence, connectivity is increasingly disrupted in many species, which might have serious consequences that could ultimately lead to the extinction of populations. Although a large number of reserves and conservation sites are designated and protected by law, potential habitats acting as inter-population connectivity corridors are, however, mostly ignored in the common practice of environmental planning. In most cases, this is mainly caused by a lack of quantitative measures of functional connectivity available for the planning process. In this study, we highlight the use of fine-scale potential connectivity models (PCMs) derived from multispectral satellite data for the quantification of spatially explicit habitat corridors for matrix-sensitive species of conservation concern. This framework couples a species distribution model with a connectivity model in a two-step framework, where suitability maps from step 1 are transformed into maps of landscape resistance in step 2 filtered by fragmentation thresholds. We illustrate the approach using the sand lizard ( Lacerta agilis L.) in the metropolitan area of Cologne, Germany, as a case study. Our model proved to be well suited to identify connected as well as completely isolated populations within the study area. Furthermore, due to its fine resolution, the PCM was also able to detect small linear structures known to be important for sand lizards' inter-population connectivity such as railroad embankments. We discuss the applicability and possible implementation of PCMs to overcome shortcomings in the common practice of environmental impact assessments.

Genetic basis of hybrid male sterility among three closely related species of Drosophila.

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Mishra, Paras Kumar; Singh, B N

2005-05-01

The genetic basis of hybrid male sterility among three closely related species, Drosophila bipectinata, D. parabipectinata and D. malerkotliana has been investigated by using backcross analysis methods. The role of Y chromosome, major hybrid sterility (MHS) genes (genetic factors) and cytoplasm (non-genetic factor) have been studied in the hybrids of these three species. In the species pair, bipectinata--parabipectinata, Y chromosome introgression of parabipectinata in the genomic background of bipectinata and the reciprocal Y chromosome introgression were unsuccessful as all males in second backcross generation were sterile. Neither MHS genes nor cytoplasm was found important for sterility. This suggests the involvement of X-Y, X-autosomes or polygenic interactions in hybrid male sterility. In bipectinata--malerkotliana and parabipectinata--malerkotliana species pairs, Y chromosome substitution in reciprocal crosses did not affect male fertility. Backcross analyses also show no involvement of MHS genes or cytoplasm in hybrid male sterility in these two species pairs. Therefore, X- autosome interaction or polygenic interaction is supposed to be involved in hybrid male sterility in these two species pairs. These findings also provide evidence that even in closely related species, genetic interactions underlying hybrid male sterility may vary.

Improving ecological risk assessment by including bioavailability into species sensitivity distributions: an example for plants exposed to nickel in soil

NARCIS (Netherlands)

Semenzin, E.; Temminghoff, E.J.M.; Marcomini, A.

2007-01-01

The variability of species sensitivity distribution (SSD) due to contaminant bioavailability in soil was explored by using nickel as metal of concern. SSDs of toxicity test results of Avena sativa L. originating from different soils and expressed as total content and available (0.01 M CaCl2)

Use of Wild Relatives and Closely Related Species to Adapt Common Bean to Climate Change

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James D. Kelly

2013-05-01

Full Text Available Common bean (Phaseolus vulgaris L. is an important legume crop worldwide. However, abiotic and biotic stress limits bean yields to <600 kg ha−1 in low-income countries. Current low yields result in food insecurity, while demands for increased yields to match the rate of population growth combined with the threat of climate change are significant. Novel and significant advances in genetic improvement using untapped genetic diversity available in crop wild relatives and closely related species must be further explored. A meeting was organized by the Global Crop Diversity Trust to consider strategies for common bean improvement. This review resulted from that meeting and considers our current understanding of the genetic resources available for common bean improvement and the progress that has been achieved thus far through introgression of genetic diversity from wild relatives of common bean, and from closely related species, including: P. acutifolius, P. coccineus, P. costaricensis and P. dumosus. Newly developed genomic tools and their potential applications are presented. A broad outline of research for use of these genetic resources for common bean improvement in a ten-year multi-disciplinary effort is presented.

Enhanced degradation of haloacid by heterologous expression in related Burkholderia species.

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Su, Xianbin; Deng, Liyu; Kong, Ka Fai; Tsang, Jimmy S H

2013-10-01

Haloacids are environmental pollutant and can be transformed to non-toxic alkanoic acids by microbial dehalogenase. Bacterium Burkholderia species MBA4 was enriched from soil for its ability to bioremediate haloacids such as mono-chloroacetate (MCA), mono-bromoacetate (MBA), 2-mono-chloropropionate, and 2-mono-bromopropionate. MBA4 produces an inducible dehalogenase Deh4a that catalyzes the dehalogenation process. The growth of MBA4 on haloacid also relies on the presence of a haloacid-uptake system. Similar dehalogenase genes can be found in the genome of many related species. However, wildtype Burkholderia caribensis MWAP64, Burkholderia phymatum STM815, and Burkholderia xenovorans LB400 were not able to grow on MCA. When a plasmid containing the regulatory and structural gene of Deh4a was transformed to these species, they were able to grow on haloacid. The specific enzyme activities in these recombinants ranges from 2- to 30-fold that of MBA4 in similar condition. Reverse transcription-quantitative real-time PCR showed that the relative transcript levels in these recombinant strains ranges from 9 to over 1,600 times that of MBA4 in similar condition. A recombinant has produced nearly five times of dehalogenase that MBA4 could ever achieve. While the expressions of Deh4a were more relaxed in these phylogenetically related species, an MCA-uptake activity was found to be inducible. These metabolically engineered strains are better degraders than the haloacid-enriched MBA4. Copyright © 2013 Wiley Periodicals, Inc.

Sensitivity of submersed freshwater macrophytes and endpoints in laboratory toxicity tests

International Nuclear Information System (INIS)

Arts, Gertie H.P.; Belgers, J. Dick M.; Hoekzema, Conny H.; Thissen, Jac T.N.M.

2008-01-01

The toxicological sensitivity and variability of a range of macrophyte endpoints were statistically tested with data from chronic, non-axenic, macrophyte toxicity tests. Five submersed freshwater macrophytes, four pesticides/biocides and 13 endpoints were included in the statistical analyses. Root endpoints, reflecting root growth, were most sensitive in the toxicity tests, while endpoints relating to biomass, growth and shoot length were less sensitive. The endpoints with the lowest coefficients of variation were not necessarily the endpoints, which were toxicologically most sensitive. Differences in sensitivity were in the range of 10-1000 for different macrophyte-specific endpoints. No macrophyte species was consistently the most sensitive. Criteria to select endpoints in macrophyte toxicity tests should include toxicological sensitivity, variance and ecological relevance. Hence, macrophyte toxicity tests should comprise an array of endpoints, including very sensitive endpoints like those relating to root growth. - A range of endpoints is more representative of macrophyte fitness than biomass and growth only

Aspergillus fumigatus and Related Species

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Sugui, Janyce A.; Kwon-Chung, Kyung J.; Juvvadi, Praveen R.; Latgé, Jean-Paul; Steinbach, William J.

2015-01-01

The genus Aspergillus contains etiologic agents of aspergillosis. The clinical manifestations of the disease range from allergic reaction to invasive pulmonary infection. Among the pathogenic aspergilli, Aspergillus fumigatus is most ubiquitous in the environment and is the major cause of the disease, followed by Aspergillus flavus, Aspergillus niger, Aspergillus terreus, Aspergillus nidulans, and several species in the section Fumigati that morphologically resemble A. fumigatus. Patients that are at risk for acquiring aspergillosis are those with an altered immune system. Early diagnosis, species identification, and adequate antifungal therapy are key elements for treatment of the disease, especially in cases of pulmonary invasive aspergillosis that often advance very rapidly. Incorporating knowledge of the basic biology of Aspergillus species to that of the diseases that they cause is fundamental for further progress in the field. PMID:25377144

Bacteroides species produce Vibrio harveyi autoinducer 2-related molecules.

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Antunes, Luis Caetano Martha; Ferreira, Lívia Queiroz; Ferreira, Eliane Oliveira; Miranda, Karla Rodrigues; Avelar, Kátia Eliane Santos; Domingues, Regina Maria Cavalcanti Pilotto; Ferreira, Maria Candida de Souza

2005-10-01

Quorum sensing is a density-dependent gene regulation mechanism that has been described in many bacterial species in the last decades. Bacteria that use quorum sensing as part of their gene regulation circuits produce molecules called autoinducers that accumulate in the environment and activate target genes in a quorum-dependent way. Some specific clues led us to hypothesize that Bacteroides species can produce autoinducers and possess a quorum sensing system. First, Bacteroides are anaerobic bacteria that are frequently involved in polymicrobial infections. These infections often involve Pseudomonas aeruginosa and Staphylococcus aureus, two of the best understood examples of bacteria that employ quorum sensing systems as part of their pathogenesis. Also, studies have detected the presence of a quorum sensing gene involved in the production of autoinducers in Porphyromonas gingivalis, a species closely related to the Bacteroides genus. These and other evidences prompted us to investigate if Bacteroides strains could produce autoinducer molecules that could be detected by a Vibrio harveyi reporter system. In this paper, we show that supernatants of B. fragilis, B. vulgatus and B. distasonis strains are able to stimulate the V. harveyi quorum sensing system 2. Also, we were able to demonstrate that the stimulation detected is due to the production of autoinducer molecules and not the growth of reporter strains after addition of supernatant. Moreover, the phenomenon observed does not seem to represent the degradation of repressors possibly present in the culture medium used. We could also amplify bands from some of the strains tested using primers designed to the luxS gene of Escherichia coli. Altogether, our results show that B. fragilis, B. vulgatus and B. distasonis (but possibly some other species) can produce V. harveyi autoinducer 2-related molecules. However, the role of such molecules in the biology of these organisms remains unknown.

Relating species abundance distributions to species-area curves in two Mediterranean-type shrublands

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Keeley, Jon E.

2003-01-01

Based on both theoretical and empirical studies there is evidence that different species abundance distributions underlie different species-area relationships. Here I show that Australian and Californian shrubland communities (at the scale from 1 to 1000 m2) exhibit different species-area relationships and different species abundance patterns. The species-area relationship in Australian heathlands best fits an exponential model and species abundance (based on both density and cover) follows a narrow log normal distribution. In contrast, the species-area relationship in Californian shrublands is best fit with the power model and, although species abundance appears to fit a log normal distribution, the distribution is much broader than in Australian heathlands. I hypothesize that the primary driver of these differences is the abundance of small-stature annual species in California and the lack of annuals in Australian heathlands. Species-area is best fit by an exponential model in Australian heathlands because the bulk of the species are common and thus the species-area curves initially rise rapidly between 1 and 100 m2. Annuals in Californian shrublands generate very broad species abundance distributions with many uncommon or rare species. The power function is a better model in these communities because richness increases slowly from 1 to 100 m2 but more rapidly between 100 and 1000 m2due to the abundance of rare or uncommon species that are more likely to be encountered at coarser spatial scales. The implications of this study are that both the exponential and power function models are legitimate representations of species-area relationships in different plant communities. Also, structural differences in community organization, arising from different species abundance distributions, may lead to different species-area curves, and this may be tied to patterns of life form distribution.

Sensitivity analysis and related analysis : A survey of statistical techniques

NARCIS (Netherlands)

Kleijnen, J.P.C.

1995-01-01

This paper reviews the state of the art in five related types of analysis, namely (i) sensitivity or what-if analysis, (ii) uncertainty or risk analysis, (iii) screening, (iv) validation, and (v) optimization. The main question is: when should which type of analysis be applied; which statistical

Evaluating broad scale patterns among related species using resource experiments in tropical hummingbirds.

Science.gov (United States)

Weinstein, Ben G; Graham, Catherine H

2016-08-01

A challenge in community ecology is connecting biogeographic patterns with local scale observations. In Neotropical hummingbirds, closely related species often co-occur less frequently than expected (overdispersion) when compared to a regional species pool. While this pattern has been attributed to interspecific competition, it is important to connect these findings with local scale mechanisms of coexistence. We measured the importance of the presence of competitors and the availability of resources on selectivity at experimental feeders for Andean hummingbirds along a wide elevation gradient. Selectivity was measured as the time a bird fed at a feeder with a high sucrose concentration when presented with feeders of both low and high sucrose concentrations. Resource selection was measured using time-lapse cameras to identity which floral resources were used by each hummingbird species. We found that the increased abundance of preferred resources surrounding the feeder best explained increased species selectivity, and that related hummingbirds with similar morphology chose similar floral resources. We did not find strong support for direct agonism based on differences in body size or phylogenetic relatedness in predicting selectivity. These results suggest closely related hummingbird species have overlapping resource niches, and that the intensity of interspecific competition is related to the abundance of those preferred resources. If these competitive interactions have negative demographic effects, our results could help explain the pattern of phylogenetic overdispersion observed at regional scales. © 2016 by the Ecological Society of America.

Wide prevalence of hybridization in two sympatric grasshopper species may be shaped by their relative abundances.

Science.gov (United States)

Rohde, Katja; Hau, Yvonne; Weyer, Jessica; Hochkirch, Axel

2015-09-16

Hybridization between species is of conservation concern as it might threaten the genetic integrity of species. Anthropogenic factors can alter hybridization dynamics by introducing new potentially hybridizing species or by diminishing barriers to hybridization. This may even affect sympatric species pairs through environmental change, which so far has received little attention. We studied hybridization prevalence and the underlying behavioral mechanisms in two sympatric grasshopper species, a rare specialist (Chorthippus montanus) and a common generalist (Chorthippus parallelus). We conducted a mate choice experiment with constant intraspecific density and varying heterospecific density, i.e. varying relative frequency of both species. Mate choice was frequency-dependent in both species with a higher risk of cross-mating with increasing heterospecific frequency, while conspecific mating increased linearly with increasing conspecific density. This illustrates that reproductive barriers could be altered by environmental change, if the relative frequency of species pairs is affected. Moreover, we performed a microsatellite analysis to detect hybridization in twelve syntopic populations (and four allotopic populations). Hybrids were detected in nearly all syntopic populations with hybridization rates reaching up to 8.9 %. Genetic diversity increased for both species when hybrids were included in the data set, but only in the common species a positive correlation between hybridization rate and genetic diversity was detected. Our study illustrates that the relative frequency of the two species strongly determines the effectiveness of reproductive barriers and that even the more choosy species (Ch. montanus) may face a higher risk of hybridization if population size decreases and its relative frequency becomes low compared to its sister species. The asymmetric mate preferences of both species may lead to quasi-unidirectional gene flow caused by unidirectional

Does the hearing sensitivity in thorny catfishes depend on swim bladder morphology?

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Angelika Zebedin

Full Text Available BACKGROUND: Thorny catfishes exhibit large variations in swim bladder morphology. These organs are of different sizes, forms and may have simple or branched diverticula. The swim bladder plays an important role in otophysans because it enhances their hearing sensitivity by transmitting sound pressure fluctuations via ossicles to the inner ear. METHODOLOGY/PRINCIPAL FINDINGS: To investigate if a form-function relationship exists, the swim bladder morphology and hearing ability were analyzed in six species. The morphology was quantified by measuring the length, width and height and calculating a standardized swim bladder length (sSBL, which was then used to calculate the relative swim bladder length (rSBL. Hearing was measured using the auditory evoked potential (AEP recording technique. Two species had simple apple-shaped and four species heart-shaped (cordiform bladders. One of the latter species had short unbranched diverticula on the terminal margin, two had a secondary bladder and two had many long, branched diverticula. The rSBL differed significantly between most of the species. All species were able to detect frequencies between 70 Hz and 6 kHz, with lowest thresholds found between 0.5 and 1 kHz (60 dB re 1 µPa. Hearing curves were U-shaped except in Hemidoras morrisi in which it was ramp-like. Mean hearing thresholds of species possessing smaller rSBLs were slightly lower (maximum 8.5 dB than those of species having larger rSBLs. CONCLUSIONS/SIGNIFICANCE: The current findings reveal a relationship between swim bladder form and its function among thorny catfishes. Relatively smaller swim bladders resulted in relatively better hearing. This is in contrast to a prior inter-familial study on catfishes in which species with large unpaired bladders possessed higher sensitivity at higher frequencies than species having tiny paired and encapsulated bladders.

Species tree estimation for the late blight pathogen, Phytophthora infestans, and close relatives.

Science.gov (United States)

Blair, Jaime E; Coffey, Michael D; Martin, Frank N

2012-01-01

To better understand the evolutionary history of a group of organisms, an accurate estimate of the species phylogeny must be known. Traditionally, gene trees have served as a proxy for the species tree, although it was acknowledged early on that these trees represented different evolutionary processes. Discordances among gene trees and between the gene trees and the species tree are also expected in closely related species that have rapidly diverged, due to processes such as the incomplete sorting of ancestral polymorphisms. Recently, methods have been developed for the explicit estimation of species trees, using information from multilocus gene trees while accommodating heterogeneity among them. Here we have used three distinct approaches to estimate the species tree for five Phytophthora pathogens, including P. infestans, the causal agent of late blight disease in potato and tomato. Our concatenation-based "supergene" approach was unable to resolve relationships even with data from both the nuclear and mitochondrial genomes, and from multiple isolates per species. Our multispecies coalescent approach using both Bayesian and maximum likelihood methods was able to estimate a moderately supported species tree showing a close relationship among P. infestans, P. andina, and P. ipomoeae. The topology of the species tree was also identical to the dominant phylogenetic history estimated in our third approach, Bayesian concordance analysis. Our results support previous suggestions that P. andina is a hybrid species, with P. infestans representing one parental lineage. The other parental lineage is not known, but represents an independent evolutionary lineage more closely related to P. ipomoeae. While all five species likely originated in the New World, further study is needed to determine when and under what conditions this hybridization event may have occurred.

Host plant use among closely related Anaea butterfly species (Lepidoptera, Nymphalidae, Charaxinae

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QUEIROZ J. M.

2002-01-01

Full Text Available There is a great number of Charaxinae (Lepidoptera: Nymphalidae species in the tropics whose larvae feed on several plant families. However the genus Anaea is almost always associated with Croton species (Euphorbiaceae. This work describes patterns of host plant use by immature and adult abundance on different vertical strata of sympatric Anaea species in a forest of Southeastern Brazil. Quantitative samples of leaves were taken in April/1999 and May/2000 to collect eggs and larvae of four Anaea species on C.alchorneicarpus, C. floribundus and C. salutaris in a semideciduous forest. Sampled leaves were divided into three classes of plant phenological stage: saplings, shrubs and trees. The results showed that the butterfly species are segregating in host plant use on two scales: host plant species and plant phenological stages. C. alchorneicarpus was used by only one Anaea species, whereas C. floribundus was used by three species and C. salutaris by four Anaea species. There was one Anaea species concentrated on sapling, another on sapling/shrub and two others on shrub/tree leaves. Adults of Anaea were more frequent at canopy traps but there were no differences among species caught in traps at different vertical positions. This work supplements early studies on host plant use among Charaxinae species and it describes how a guild of closely related butterfly species may be organized in a complex tropical habitat.

Identification of Pseudallescheria and Scedosporium Species by Three Molecular Methods▿

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Lu, Qiaoyun; Gerrits van den Ende, A. H. G.; Bakkers, J. M. J. E.; Sun, Jiufeng; Lackner, M.; Najafzadeh, M. J.; Melchers, W. J. G.; Li, Ruoyu; de Hoog, G. S.

2011-01-01

The major clinically relevant species in Scedosporium (teleomorph Pseudallescheria) are Pseudallescheria boydii, Scedosporium aurantiacum, Scedosporium apiospermum, and Scedosporium prolificans, while Pseudallescheria minutispora, Petriellopsis desertorum, and Scedosporium dehoogii are exceptional agents of disease. Three molecular methods targeting the partial β-tubulin gene were developed and evaluated to identify six closely related species of the S. apiospermum complex using quantitative real-time PCR (qPCR), PCR-based reverse line blot (PCR-RLB), and loop-mediated isothermal amplification (LAMP). qPCR was not specific enough for the identification of all species but had the highest sensitivity. The PCR-RLB assay was efficient for the identification of five species. LAMP distinguished all six species unambiguously. The analytical sensitivities of qPCR, PCR-RLB, and LAMP combined with MagNAPure, CTAB (cetyltrimethylammonium bromide), and FTA filter (Whatman) extraction were 50, 5 × 103, and 5 × 102 cells/μl, respectively. When LAMP was combined with a simplified DNA extraction method using an FTA filter, identification to the species level was achieved within 2 h, including DNA extraction. The FTA-LAMP assay is therefore recommended as a cost-effective, simple, and rapid method for the identification of Scedosporium species. PMID:21177887

Protectiveness of Species Sensitivity Distribution Hazard Concentrations for Acute Toxicity Used in Endangered Species Risk Assessment

Science.gov (United States)

A primary objective of threatened and endangered species conservation is to ensure that chemical contaminants and other stressors do not adversely affect listed species. Assessments of the ecological risks of chemical exposures to listed species often rely on the use of surrogate...

Stress Sensitivity Is Associated with Differential Accumulation of Reactive Oxygen and Nitrogen Species in Maize Genotypes with Contrasting Levels of Drought Tolerance

Science.gov (United States)

Yang, Liming; Fountain, Jake C.; Wang, Hui; Ni, Xinzhi; Ji, Pingsheng; Lee, Robert D.; Kemerait, Robert C.; Scully, Brian T.; Guo, Baozhu

2015-01-01

Drought stress decreases crop growth, yield, and can further exacerbate pre-harvest aflatoxin contamination. Tolerance and adaptation to drought stress is an important trait of agricultural crops like maize. However, maize genotypes with contrasting drought tolerances have been shown to possess both common and genotype-specific adaptations to cope with drought stress. In this research, the physiological and metabolic response patterns in the leaves of maize seedlings subjected to drought stress were investigated using six maize genotypes including: A638, B73, Grace-E5, Lo964, Lo1016, and Va35. During drought treatments, drought-sensitive maize seedlings displayed more severe symptoms such as chlorosis and wilting, exhibited significant decreases in photosynthetic parameters, and accumulated significantly more reactive oxygen species (ROS) and reactive nitrogen species (RNS) than tolerant genotypes. Sensitive genotypes also showed rapid increases in enzyme activities involved in ROS and RNS metabolism. However, the measured antioxidant enzyme activities were higher in the tolerant genotypes than in the sensitive genotypes in which increased rapidly following drought stress. The results suggest that drought stress causes differential responses to oxidative and nitrosative stress in maize genotypes with tolerant genotypes with slower reaction and less ROS and RNS production than sensitive ones. These differential patterns may be utilized as potential biological markers for use in marker assisted breeding. PMID:26492235

Stress Sensitivity Is Associated with Differential Accumulation of Reactive Oxygen and Nitrogen Species in Maize Genotypes with Contrasting Levels of Drought Tolerance

Directory of Open Access Journals (Sweden)

Liming Yang

2015-10-01

Full Text Available Drought stress decreases crop growth, yield, and can further exacerbate pre-harvest aflatoxin contamination. Tolerance and adaptation to drought stress is an important trait of agricultural crops like maize. However, maize genotypes with contrasting drought tolerances have been shown to possess both common and genotype-specific adaptations to cope with drought stress. In this research, the physiological and metabolic response patterns in the leaves of maize seedlings subjected to drought stress were investigated using six maize genotypes including: A638, B73, Grace-E5, Lo964, Lo1016, and Va35. During drought treatments, drought-sensitive maize seedlings displayed more severe symptoms such as chlorosis and wilting, exhibited significant decreases in photosynthetic parameters, and accumulated significantly more reactive oxygen species (ROS and reactive nitrogen species (RNS than tolerant genotypes. Sensitive genotypes also showed rapid increases in enzyme activities involved in ROS and RNS metabolism. However, the measured antioxidant enzyme activities were higher in the tolerant genotypes than in the sensitive genotypes in which increased rapidly following drought stress. The results suggest that drought stress causes differential responses to oxidative and nitrosative stress in maize genotypes with tolerant genotypes with slower reaction and less ROS and RNS production than sensitive ones. These differential patterns may be utilized as potential biological markers for use in marker assisted breeding.

Lactobacillus herbarum sp. nov., a species related to Lactobacillus plantarum.

Science.gov (United States)

Mao, Yuejian; Chen, Meng; Horvath, Philippe

2015-12-01

Strain TCF032-E4 was isolated from a traditional Chinese fermented radish. It shares >99% 16S rRNA sequence identity with L. plantarum, L. pentosus and L. paraplantarum. This strain can ferment ribose, galactose, glucose, fructose, mannose, mannitol, N-acetylglucosamine, amygdalin, arbutin, salicin, cellobiose, maltose, lactose, melibiose, trehalose and gentiobiose. It cannot ferment sucrose, which can be used by L. pentosus, L. paraplantarum, L. fabifermentans, L. xiangfangensis and L. mudanjiangensis, as well as most of the L. plantarum strains (88.7%). TCF032-E4 cannot grow at temperature above 32 °C. This strain shares 78.2-83.6% pheS (phenylalanyl-tRNA synthetase alpha subunit) and 89.5-94.9% rpoA (RNA polymerase alpha subunit) sequence identity with L. plantarum, L. pentosus, L. paraplantarum, L. fabifermentans, L. xiangfangensis and L. mudanjiangensis. These results indicate that TCF032-E4 represents a distinct species. This hypothesis was further confirmed by whole-genome sequencing and comparison with available genomes of related species. The draft genome size of TCF032-E4 is approximately 2.9 Mb, with a DNA G+C content of 43.5 mol%. The average nucleotide identity (ANI) between TCF032-E4 and related species ranges from 79.0 to 81.1%, the highest ANI value being observed with L. plantarum subsp. plantarum ATCC 14917T. A novel species, Lactobacillus herbarum sp. nov., is proposed with TCF032-E4T ( = CCTCC AB2015090T = DSM 100358T) as the type strain.

Improving ecological risk assessment by including bioavailability into species sensitivity distributions: An example for plants exposed to nickel in soil

International Nuclear Information System (INIS)

Semenzin, Elena; Temminghoff, Erwin J.M.; Marcomini, Antonio

2007-01-01

The variability of species sensitivity distribution (SSD) due to contaminant bioavailability in soil was explored by using nickel as metal of concern. SSDs of toxicity test results of Avena sativa L. originating from different soils and expressed as total content and available (0.01 M CaCl 2 ) extractable concentration were compared to SSDs for terrestrial plants derived from literature toxicity data. Also the 'free' nickel (Ni 2+ ) concentration was calculated and compared. The results demonstrated that SSDs based on total nickel content highly depend on the experimental conditions set up for toxicity testing (i.e. selected soil and pH value) and thus on metal bioavailability in soil, resulting in an unacceptable uncertainty for ecological risk estimation. The use in SSDs of plant toxicity data expressed as 0.01 M CaCl 2 extractable metal strongly reduced the uncertainty in the SSD curve and thus can improve the ERA procedure remarkably by taking bioavailability into account. - The use of bioavailability toxicity data can improve species sensitivity distribution (SSD) curves and thus ecological risk assessment (ERA)

Molecular Diagnosis of Pathogenic Sporothrix Species.

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Anderson Messias Rodrigues

2015-12-01

Full Text Available Sporotrichosis is a chronic (subcutaneous infection caused by thermodimorphic fungi in the order, Ophiostomatales. These fungi are characterized by major differences in routes of transmission, host predilections, species virulence, and susceptibilities to antifungals. Sporothrix species emerge in the form of outbreaks. Large zoonoses and sapronoses are ongoing in Brazil and China, respectively. Current diagnostic methods based on morphology and physiology are inaccurate due to closely related phenotypes with overlapping components between pathogenic and non-pathogenic Sporothrix. There is a critical need for new diagnostic tools that are specific, sensitive, and cost-effective.We developed a panel of novel markers, based on calmodulin (CAL gene sequences, for the large-scale diagnosis and epidemiology of clinically relevant members of the Sporothrix genus, and its relative, Ophiostoma. We identified specific PCR-based markers for S. brasiliensis, S. schenckii, S. globosa, S. mexicana, S. pallida, and O. stenoceras. We employed a murine model of disseminated sporotrichosis to optimize a PCR assay for detecting Sporothrix in clinical specimens.Primer-BLAST searches revealed candidate sequences that were conserved within a single species. Species-specific primers showed no significant homology with human, mouse, or microorganisms outside the Sporothrix genus. The detection limit was 10-100 fg of DNA in a single round of PCR for identifying S. brasiliensis, S. schenckii, S. globosa, S. mexicana, and S. pallida. A simple, direct PCR assay, with conidia as a source of DNA, was effective for rapid, low-cost genotyping. Samples from a murine model of disseminated sporotrichosis confirmed the feasibility of detecting S. brasiliensis and S. schenckii DNA in spleen, liver, lungs, heart, brain, kidney, tail, and feces of infected animals.This PCR-based method could successfully detect and identify a single species in samples from cultures and from clinical

Long-term changes in species composition and relative abundances of sharks at a provisioning site.

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Juerg M Brunnschweiler

Full Text Available Diving with sharks, often in combination with food baiting/provisioning, has become an important product of today's recreational dive industry. Whereas the effects baiting/provisioning has on the behaviour and abundance of individual shark species are starting to become known, there is an almost complete lack of equivalent data from multi-species shark diving sites. In this study, changes in species composition and relative abundances were determined at the Shark Reef Marine Reserve, a multi-species shark feeding site in Fiji. Using direct observation sampling methods, eight species of sharks (bull shark Carcharhinus leucas, grey reef shark Carcharhinus amblyrhynchos, whitetip reef shark Triaenodon obesus, blacktip reef shark Carcharhinus melanopterus, tawny nurse shark Nebrius ferrugineus, silvertip shark Carcharhinus albimarginatus, sicklefin lemon shark Negaprion acutidens, and tiger shark Galeocerdo cuvier displayed inter-annual site fidelity between 2003 and 2012. Encounter rates and/or relative abundances of some species changed over time, overall resulting in more individuals (mostly C. leucas of fewer species being encountered on average on shark feeding dives at the end of the study period. Differences in shark community composition between the years 2004-2006 and 2007-2012 were evident, mostly because N. ferrugineus, C. albimarginatus and N. acutidens were much more abundant in 2004-2006 and very rare in the period of 2007-2012. Two explanations are offered for the observed changes in relative abundances over time, namely inter-specific interactions and operator-specific feeding protocols. Both, possibly in combination, are suggested to be important determinants of species composition and encounter rates, and relative abundances at this shark provisioning site in Fiji. This study, which includes the most species from a spatially confined shark provisioning site to date, suggests that long-term provisioning may result in competitive

Long-term changes in species composition and relative abundances of sharks at a provisioning site.

Science.gov (United States)

Brunnschweiler, Juerg M; Abrantes, Kátya G; Barnett, Adam

2014-01-01

Diving with sharks, often in combination with food baiting/provisioning, has become an important product of today's recreational dive industry. Whereas the effects baiting/provisioning has on the behaviour and abundance of individual shark species are starting to become known, there is an almost complete lack of equivalent data from multi-species shark diving sites. In this study, changes in species composition and relative abundances were determined at the Shark Reef Marine Reserve, a multi-species shark feeding site in Fiji. Using direct observation sampling methods, eight species of sharks (bull shark Carcharhinus leucas, grey reef shark Carcharhinus amblyrhynchos, whitetip reef shark Triaenodon obesus, blacktip reef shark Carcharhinus melanopterus, tawny nurse shark Nebrius ferrugineus, silvertip shark Carcharhinus albimarginatus, sicklefin lemon shark Negaprion acutidens, and tiger shark Galeocerdo cuvier) displayed inter-annual site fidelity between 2003 and 2012. Encounter rates and/or relative abundances of some species changed over time, overall resulting in more individuals (mostly C. leucas) of fewer species being encountered on average on shark feeding dives at the end of the study period. Differences in shark community composition between the years 2004-2006 and 2007-2012 were evident, mostly because N. ferrugineus, C. albimarginatus and N. acutidens were much more abundant in 2004-2006 and very rare in the period of 2007-2012. Two explanations are offered for the observed changes in relative abundances over time, namely inter-specific interactions and operator-specific feeding protocols. Both, possibly in combination, are suggested to be important determinants of species composition and encounter rates, and relative abundances at this shark provisioning site in Fiji. This study, which includes the most species from a spatially confined shark provisioning site to date, suggests that long-term provisioning may result in competitive exclusion among shark

Traits related to species persistence and dispersal explain changes in plant communities subjected to habitat loss

DEFF Research Database (Denmark)

Marini, Lorenzo; Bruun, Hans Henrik; Heikkinen, Risto

2012-01-01

Aim Habitat fragmentation is a major driver of biodiversity loss but it is insufficiently known how much its effects vary among species with different life-history traits; especially in plant communities, the understanding of the role of traits related to species persistence and dispersal in dete...... rural landscapes in NW Europe, mitigating the spatial isolation of remaining grasslands should be accompanied by restoration measures aimed at improving habitat quality for low competitors, abiotically dispersed and perennial, clonal species.......Aim Habitat fragmentation is a major driver of biodiversity loss but it is insufficiently known how much its effects vary among species with different life-history traits; especially in plant communities, the understanding of the role of traits related to species persistence and dispersal...... in determining dynamics of species communities in fragmented landscapes is still limited. The primary aim of this study was to test how plant traits related to persistence and dispersal and their interactions modify plant species vulnerability to decreasing habitat area and increasing isolation. Location Five...

Polymorphic microsatellite markers for the endangered fish, the slender shiner Pseudopungtungia tenuicorpa and cross-species amplification across five related species.

Science.gov (United States)

Kim, K S; Moon, S J; Han, S H; Kim, K Y; Bang, I C

2016-09-02

The slender shiner Pseudopungtungia tenuicorpa (Cypriniformes; Cyprinidae; Gobioninae) is an endangered freshwater fish species endemic to Korea. The current strategies for its conservation involve the study of population genetic characters and identification of management units. These strategies require suitable molecular markers to study genetic diversity and genetic structure. Here, we developed nine polymorphic microsatellite markers for P. tenuicorpa for the first time by applying an enrichment method from a size-selected genomic library. The developed microsatellite markers produced a total of 101 alleles (average 11.2). The observed and expected heterozygosities averaged 0.805 and 0.835, respectively. Among the nine identified markers, five markers showed successful amplification across five related Korean Gobioninae species. Thus, the microsatellite markers developed in this study will be useful to establish conservation strategies for both P. tenuicorpa and other related species.

Catheter-related bacteraemia and infective endocarditis caused by Kocuria species.

Science.gov (United States)

Lai, C C; Wang, J Y; Lin, S H; Tan, C K; Wang, C Y; Liao, C H; Chou, C H; Huang, Y T; Lin, H I; Hsueh, P R

2011-02-01

We describe five patients with positive blood culture for Kocuria species. Three patients had catheter-related bacteraemia and one had infective endocarditis caused by Kocuria kristinae, and one had a K. marina isolate, which was considered to be a contaminant. Identification of the isolates was further confirmed by 16S rRNA gene sequence analysis. In conclusion, Kocuria species are an unusual cause of infection in immunocompromised patients. Accurate identification with molecular methods is imperative for the diagnosis of these unusual pathogens. © 2010 The Authors. Journal Compilation © 2010 European Society of Clinical Microbiology and Infectious Diseases.

DNA-based species detection capabilities using laser transmission spectroscopy.

Science.gov (United States)

Mahon, A R; Barnes, M A; Li, F; Egan, S P; Tanner, C E; Ruggiero, S T; Feder, J L; Lodge, D M

2013-01-06

Early detection of invasive species is critical for effective biocontrol to mitigate potential ecological and economic damage. Laser transmission spectroscopy (LTS) is a powerful solution offering real-time, DNA-based species detection in the field. LTS can measure the size, shape and number of nanoparticles in a solution and was used here to detect size shifts resulting from hybridization of the polymerase chain reaction product to nanoparticles functionalized with species-specific oligonucleotide probes or with the species-specific oligonucleotide probes alone. We carried out a series of DNA detection experiments using the invasive freshwater quagga mussel (Dreissena bugensis) to evaluate the capability of the LTS platform for invasive species detection. Specifically, we tested LTS sensitivity to (i) DNA concentrations of a single target species, (ii) the presence of a target species within a mixed sample of other closely related species, (iii) species-specific functionalized nanoparticles versus species-specific oligonucleotide probes alone, and (iv) amplified DNA fragments versus unamplified genomic DNA. We demonstrate that LTS is a highly sensitive technique for rapid target species detection, with detection limits in the picomolar range, capable of successful identification in multispecies samples containing target and non-target species DNA. These results indicate that the LTS DNA detection platform will be useful for field application of target species. Additionally, we find that LTS detection is effective with species-specific oligonucleotide tags alone or when they are attached to polystyrene nanobeads and with both amplified and unamplified DNA, indicating that the technique may also have versatility for broader applications.

Species tree estimation for the late blight pathogen, Phytophthora infestans, and close relatives.

Directory of Open Access Journals (Sweden)

Jaime E Blair

Full Text Available To better understand the evolutionary history of a group of organisms, an accurate estimate of the species phylogeny must be known. Traditionally, gene trees have served as a proxy for the species tree, although it was acknowledged early on that these trees represented different evolutionary processes. Discordances among gene trees and between the gene trees and the species tree are also expected in closely related species that have rapidly diverged, due to processes such as the incomplete sorting of ancestral polymorphisms. Recently, methods have been developed for the explicit estimation of species trees, using information from multilocus gene trees while accommodating heterogeneity among them. Here we have used three distinct approaches to estimate the species tree for five Phytophthora pathogens, including P. infestans, the causal agent of late blight disease in potato and tomato. Our concatenation-based "supergene" approach was unable to resolve relationships even with data from both the nuclear and mitochondrial genomes, and from multiple isolates per species. Our multispecies coalescent approach using both Bayesian and maximum likelihood methods was able to estimate a moderately supported species tree showing a close relationship among P. infestans, P. andina, and P. ipomoeae. The topology of the species tree was also identical to the dominant phylogenetic history estimated in our third approach, Bayesian concordance analysis. Our results support previous suggestions that P. andina is a hybrid species, with P. infestans representing one parental lineage. The other parental lineage is not known, but represents an independent evolutionary lineage more closely related to P. ipomoeae. While all five species likely originated in the New World, further study is needed to determine when and under what conditions this hybridization event may have occurred.

Right Hemisphere Sensitivity to Novel Metaphoric Relations: Application of the Signal Detection Theory

Science.gov (United States)

Mashal, N.; Faust, M.

2008-01-01

The present study used the signal detection theory to test the hypothesis that the right hemisphere (RH) is more sensitive than the left hemisphere (LH) to the distant semantic relations in novel metaphoric expressions. In two divided visual field experiments, sensitivity (d') and criterion ([beta]) were calculated for responses to different types…

Hydraulic lift and tolerance to salinity of semiarid species: consequences for species interactions.

Science.gov (United States)

Armas, Cristina; Padilla, Francisco M; Pugnaire, Francisco I; Jackson, Robert B

2010-01-01

The different abilities of plant species to use ephemeral or permanent water sources strongly affect physiological performance and species coexistence in water-limited ecosystems. In addition to withstanding drought, plants in coastal habitats often have to withstand highly saline soils, an additional ecological stress. Here we tested whether observed competitive abilities and C-water relations of two interacting shrub species from an arid coastal system were more related to differences in root architecture or salinity tolerance. We explored water sources of interacting Juniperus phoenicea Guss. and Pistacia lentiscus L. plants by conducting physiology measurements, including water relations, CO2 exchange, photochemical efficiency, sap osmolality, and water and C isotopes. We also conducted parallel soil analyses that included electrical conductivity, humidity, and water isotopes. During drought, Pistacia shrubs relied primarily on permanent salty groundwater, while isolated Juniperus plants took up the scarce and relatively fresh water stored in upper soil layers. As drought progressed further, the physiological activity of Juniperus plants nearly stopped while Pistacia plants were only slightly affected. Juniperus plants growing with Pistacia had stem-water isotopes that matched Pistacia, unlike values for isolated Juniperus plants. This result suggests that Pistacia shrubs supplied water to nearby Juniperus plants through hydraulic lift. This lifted water, however, did not appear to benefit Juniperus plants, as their physiological performance with co-occurring Pistacia plants was poor, including lower water potentials and rates of photosynthesis than isolated plants. Juniperus was more salt sensitive than Pistacia, which withstood salinity levels similar to that of groundwater. Overall, the different abilities of the two species to use salty water appear to drive the outcome of their interaction, resulting in asymmetric competition where Juniperus is negatively

How Is Interreligious Sensitivity Related to Finnish Pupils' Religiousness Profiles?

Science.gov (United States)

Kuusisto, Elina; Kuusisto, Arniika; Kallioniemi, Arto

2016-01-01

This paper examines, through a non-probability sample of 451 Finnish lower secondary-school pupils belonging to the 15- to 16-year-old age group, how interreligious sensitivity is related to religiousness profiles of Finnish youth. The data were gathered in two geographical locations: Helsinki, Finland's capital, and a smaller municipality in the…

Bacterial and fungal endophthalmitis in upper Egypt: related species and risk factors.

Science.gov (United States)

Gharamah, A A; Moharram, A M; Ismail, M A; Al-Hussaini, A K

2012-08-01

To study risk factors, contributing factors of bacterial and fungal endophthalmitis in Upper Egypt, test the isolated species sensitive to some therapeutic agents, and to investigate the air-borne bacteria and fungi in opthalmology operating rooms. Thirty one cases of endophthalmitis were clinically diagnosed and microbiologically studied. Indoor air-borne bacteria and fungi inside four air-conditioned operating rooms in the Ophthalmology Department at Assiut University Hospitals were also investigated. The isolated microbes from endophthalmitis cases were tested for their ability to produce some extracellular enzymes including protease, lipase, urease, phosphatase and catalase. Also the ability of 5 fungal isolates from endophthalmitis origin to produce mycotoxins and their sensitivity to some therapeutic agents were studied. Results showed that bacteria and fungi were responsihle for infection in 10 and 6 cases of endophthalmitis, respectively and only 2 cases produced a mixture of bacteria and fungi. Trauma was the most prevalent risk factor of endophthalmitis where 58.1% of the 31 cases were due to trauma. In ophthalmology operating rooms, different bacterial and fungal species were isolated. 8 bacterial and 5 fungal isolates showed their ability to produce enzymes while only 3 fungal isolates were able to produce mycotoxins. Terbinafine showed the highest effect against most isolates in vitro. The ability of bacterial and fungal isolates to produce extracellular enzymes and mycotoxins may be aid in the invasion and destruction of eye tissues. Microbial contamination of operating rooms with air-borne bacteria and fungi in the present work may be a source of postoperative endophthalmitis.

Uncertainty of relative sensitivity factors in glow discharge mass spectrometry

Science.gov (United States)

Meija, Juris; Methven, Brad; Sturgeon, Ralph E.

2017-10-01

The concept of the relative sensitivity factors required for the correction of the measured ion beam ratios in pin-cell glow discharge mass spectrometry is examined in detail. We propose a data-driven model for predicting the relative response factors, which relies on a non-linear least squares adjustment and analyte/matrix interchangeability phenomena. The model provides a self-consistent set of response factors for any analyte/matrix combination of any element that appears as either an analyte or matrix in at least one known response factor.

Artificial light at night affects sleep behaviour differently in two closely related songbird species.

Science.gov (United States)

Sun, Jiachen; Raap, Thomas; Pinxten, Rianne; Eens, Marcel

2017-12-01

Artificial light at night (ALAN) or light pollution is an increasing and worldwide problem. There is growing concern that because of the disruption of natural light cycles, ALAN may pose serious risks for wildlife. While ALAN has been shown to affect many aspects of animal behaviour and physiology, few studies have experimentally studied whether individuals of different species in the wild respond differently to ALAN. Here, we investigated the effect of ALAN on sleep behaviour in two closely related songbird species inhabiting the same study area and roosting/breeding in similar nest boxes. We experimentally exposed free-living great tits (Parus major) and blue tits (Cyanistes caeruleus) to artificial light inside their nest boxes and observed changes in their sleep behaviour compared to the previous night when the nest boxes were dark. In line with previous studies, sleep behaviour of both species did not differ under dark conditions. ALAN disrupted sleep in both great and blue tits. However, compared to blue tits, great tits showed more pronounced effects and more aspects of sleep were affected. Light exposed great tits entered the nest boxes and fell asleep later, woke up and exited the nest boxes earlier, and the total sleep amount and sleep percentage were reduced. By contrast, these changes in sleep behaviour were not found in light exposed blue tits. Our field experiment, using exactly the same light manipulation in both species, provides direct evidence that two closely related species respond differently to ALAN, while their sleep behaviour under dark conditions was similar. Our research suggests that findings for one species cannot necessarily be generalised to other species, even closely-related species. Furthermore, species-specific effects could have implications for community dynamics. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sinoporphyrin sodium, a novel sensitizer, triggers mitochondrial-dependent apoptosis in ECA-109 cells via production of reactive oxygen species

Directory of Open Access Journals (Sweden)

Wang H

2014-06-01

Full Text Available Haiping Wang,1 Xiaobing Wang,1 Shaoliang Zhang,2 Pan Wang,1 Kun Zhang,1 Quanhong Liu1 1Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry, Ministry of Education, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, 2Qinglong High-Tech Co, Ltd, Yichun, Jiangxi, People's Republic of China Background: Sonodynamic therapy (SDT is a promising method that uses ultrasound to activate certain chemical sensitizers for the treatment of cancer. The purpose of this study was to investigate the sonoactivity of a novel sensitizer, sinoporphyrin sodium (DVDMS, and its sonotoxicity in an esophageal cancer (ECA-109 cell line. Methods: The fluorescence intensity of DVDMS, hematoporphyrin, protoporphyrin IX, and Photofrin II was detected by fluorescence microscopy and flow cytometry. Generation of singlet oxygen was measured using a 1, 3-diphenylisobenzofuran experiment. A 3-(4, 5-dimethylthiazol-2-yl-2, 5-diphenyl tetrazolium bromide assay was used to examine cell viability. Production of reactive oxygen species (ROS and destabilization of the mitochondrial membrane potential were assessed by flow cytometry. Apoptosis was analyzed using Annexin-PE/7-amino-actinomycin D staining. Confocal microscopy was performed to assess mitochondrial damage and identify release of cytochrome C after treatment. Western blots were used to determine expression of oxidative stress-related and apoptosis-associated protein. Ultrastructural changes in the cell were studied by scanning electron microscopy. Results: DVDMS showed higher autofluorescence intensity and singlet oxygen production efficiency compared with other photosensitizers in both cancerous and normal cells. Compared with hematoporphyrin, DVDMS-mediated SDT was more cytotoxic in ECA-109 cells. Abundant intracellular ROS was found in the SDT groups, and the cytotoxicity

Multitarget global sensitivity analysis of n-butanol combustion.

Science.gov (United States)

Zhou, Dingyu D Y; Davis, Michael J; Skodje, Rex T

2013-05-02

A model for the combustion of butanol is studied using a recently developed theoretical method for the systematic improvement of the kinetic mechanism. The butanol mechanism includes 1446 reactions, and we demonstrate that it is straightforward and computationally feasible to implement a full global sensitivity analysis incorporating all the reactions. In addition, we extend our previous analysis of ignition-delay targets to include species targets. The combination of species and ignition targets leads to multitarget global sensitivity analysis, which allows for a more complete mechanism validation procedure than we previously implemented. The inclusion of species sensitivity analysis allows for a direct comparison between reaction pathway analysis and global sensitivity analysis.

Chloroplast genome resources and molecular markers differentiate rubber dandelion species from weedy relatives.

Science.gov (United States)

Zhang, Yingxiao; Iaffaldano, Brian J; Zhuang, Xiaofeng; Cardina, John; Cornish, Katrina

2017-02-02

Rubber dandelion (Taraxacum kok-saghyz, TK) is being developed as a domestic source of natural rubber to meet increasing global demand. However, the domestication of TK is complicated by its colocation with two weedy dandelion species, Taraxacum brevicorniculatum (TB) and the common dandelion (Taraxacum officinale, TO). TB is often present as a seed contaminant within TK accessions, while TO is a pandemic weed, which may have the potential to hybridize with TK. To discriminate these species at the molecular level, and facilitate gene flow studies between the potential rubber crop, TK, and its weedy relatives, we generated genomic and marker resources for these three dandelion species. Complete chloroplast genome sequences of TK (151,338 bp), TO (151,299 bp), and TB (151,282 bp) were obtained using the Illumina GAII and MiSeq platforms. Chloroplast sequences were analyzed and annotated for all the three species. Phylogenetic analysis within Asteraceae showed that TK has a closer genetic distance to TB than to TO and Taraxacum species were most closely related to lettuce (Lactuca sativa). By sequencing multiple genotypes for each species and testing variants using gel-based methods, four chloroplast Single Nucleotide Polymorphism (SNP) variants were found to be fixed between TK and TO in large populations, and between TB and TO. Additionally, Expressed Sequence Tag (EST) resources developed for TO and TK permitted the identification of five nuclear species-specific SNP markers. The availability of chloroplast genomes of these three dandelion species, as well as chloroplast and nuclear molecular markers, will provide a powerful genetic resource for germplasm differentiation and purification, and the study of potential gene flow among Taraxacum species.

A luciferase reporter gene assay and aryl hydrocarbon receptor 1 genotype predict the LD50 of polychlorinated biphenyls in avian species

International Nuclear Information System (INIS)

Manning, Gillian E.; Farmahin, Reza; Crump, Doug; Jones, Stephanie P.; Klein, Jeff; Konstantinov, Alex; Potter, Dave; Kennedy, Sean W.

2012-01-01

Birds differ in sensitivity to the embryotoxic effects of polychlorinated biphenyls (PCBs), which complicates environmental risk assessments for these chemicals. Recent research has shown that the identities of amino acid residues 324 and 380 in the avian aryl hydrocarbon receptor 1 (AHR1) ligand binding domain (LBD) are primarily responsible for differences in avian species sensitivity to selected dibenzo-p-dioxins and furans. A luciferase reporter gene (LRG) assay was developed in our laboratory to measure AHR1-mediated induction of a cytochrome P450 1A5 reporter gene in COS-7 cells transfected with different avian AHR1 constructs. In the present study, the LRG assay was used to measure the concentration-dependent effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and PCBs 126, 77, 105 and 118 on luciferase activity in COS-7 cells transfected with AHR1 constructs representative of 86 avian species in order to predict their sensitivity to PCB-induced embryolethality and the relative potency of PCBs in these species. The results of the LRG assay indicate that the identity of amino acid residues 324 and 380 in the AHR1 LBD are the major determinants of avian species sensitivity to PCBs. The relative potency of PCBs did not differ greatly among AHR1 constructs. Luciferase activity was significantly correlated with embryolethality data obtained from the literature (R 2 ≥ 0.87, p < 0.0001). Thus, the LRG assay in combination with the knowledge of a species' AHR1 LBD sequence can be used to predict PCB-induced embryolethality in potentially any avian species of interest without the use of lethal methods on a large number of individuals. -- Highlights: ► PCB embryolethality in birds can be predicted from a species' AHR1 genotype. ► The reporter gene assay is useful for predicting species sensitivity to PCBs. ► The relative potency of PCBs does not appear to differ between AHR1 genotypes. ► Contamination of PCB 105 and PCB 118 did not affect their relative

Seasonal trends in reduced leaf gas exchange and ozone-induced foliar injury in three ozone sensitive woody plant species

International Nuclear Information System (INIS)

Novak, K.; Schaub, M.; Fuhrer, J.; Skelly, J.M.; Hug, C.; Landolt, W.; Bleuler, P.; Kraeuchi, N.

2005-01-01

Seasonal trends in leaf gas exchange and ozone-induced visible foliar injury were investigated for three ozone sensitive woody plant species. Seedlings of Populus nigra L., Viburnum lantana L., and Fraxinus excelsior L. were grown in charcoal-filtered chambers, non-filtered chambers and open plots. Injury assessments and leaf gas exchange measurements were conducted from June to October during 2002. All species developed typical ozone-induced foliar injury. For plants exposed to non-filtered air as compared to the charcoal-filtered air, mean net photosynthesis was reduced by 25%, 21%, and 18% and mean stomatal conductance was reduced by 25%, 16%, and 8% for P. nigra, V. lantana, and F. excelsior, respectively. The timing and severity of the reductions in leaf gas exchange were species specific and corresponded to the onset of visible foliar injury. - Reductions in leaf gas exchange corresponded to the onset of ozone-induced visible foliar injury for seedlings exposed to ambient ozone exposures

Seasonal trends in reduced leaf gas exchange and ozone-induced foliar injury in three ozone sensitive woody plant species

Energy Technology Data Exchange (ETDEWEB)

Novak, K. [Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zuercherstrasse 111, 8903 Birmensdorf (Switzerland)]. E-mail: kristopher.novak@wsl.ch; Schaub, M. [Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zuercherstrasse 111, 8903 Birmensdorf (Switzerland); Fuhrer, J. [Swiss Federal Research Station for Agroecology and Agriculture FAL, 8046 Zurich (Switzerland); Skelly, J.M. [Department of Plant Pathology, The Pennsylvania State University, University Park, PA 16802 (United States); Hug, C. [Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zuercherstrasse 111, 8903 Birmensdorf (Switzerland); Landolt, W. [Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zuercherstrasse 111, 8903 Birmensdorf (Switzerland); Bleuler, P. [Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zuercherstrasse 111, 8903 Birmensdorf (Switzerland); Kraeuchi, N. [Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zuercherstrasse 111, 8903 Birmensdorf (Switzerland)

2005-07-15

Seasonal trends in leaf gas exchange and ozone-induced visible foliar injury were investigated for three ozone sensitive woody plant species. Seedlings of Populus nigra L., Viburnum lantana L., and Fraxinus excelsior L. were grown in charcoal-filtered chambers, non-filtered chambers and open plots. Injury assessments and leaf gas exchange measurements were conducted from June to October during 2002. All species developed typical ozone-induced foliar injury. For plants exposed to non-filtered air as compared to the charcoal-filtered air, mean net photosynthesis was reduced by 25%, 21%, and 18% and mean stomatal conductance was reduced by 25%, 16%, and 8% for P. nigra, V. lantana, and F. excelsior, respectively. The timing and severity of the reductions in leaf gas exchange were species specific and corresponded to the onset of visible foliar injury. - Reductions in leaf gas exchange corresponded to the onset of ozone-induced visible foliar injury for seedlings exposed to ambient ozone exposures.

Unimodal models to relate species to environment

NARCIS (Netherlands)

Braak, ter C.J.F.

1987-01-01

To assess the impact of environmental change on biological communities knowledge about species-environment relationships is indispensable. Ecologists attempt to uncover the relationships between species and environment from data obtained from field surveys. In the survey, species are scored on their

Sensitivity, specificity and comparison of three commercially available immunological tests in the diagnosis of Cryptosporidium species in animals.

Science.gov (United States)

Danišová, Olga; Halánová, Monika; Valenčáková, Alexandra; Luptáková, Lenka

The study was conducted to compare the specificity of immunological diagnostic methods used for the diagnosis of Cryptosporidium species capable of causing life-threatening infection in both immunosuppressed and immunocompetent patients. For the detection of Cryptosporidium species in 79 animals with diarrhoea, we used three Copro-antigen tests: RIDASCREEN ® Cryptosporidium test, Cryptosporidium 2nd Generation (ELISA) and RIDA ® QUICK Cryptosporidium. For immunoassays we used positive and negative samples detected by means of polymerase chain reaction and validated by sequencing and nested polymerase chain reaction to confirm the presence six different species of Cryptosporidium species. Prevalence of cryptosporidiosis in the entire group determined by enzyme immunoassay, enzyme linked immunosorbent assay, immuno-chromatographic test and polymerase chain reaction was 34.17%, 27.84%, 6.33% and 27.84%, respectively. Sensitivity of animal samples with enzyme immunoassay, enzyme linked immunosorbent assay, and immuno-chromatographic test was 63.6%, 40.9% and 22.7%, resp., when questionable samples were considered positive, whereas specificity of enzyme immunoassay, enzyme linked immunosorbent assay and immuno-chromatographic test was 75.9%, 78.9% and 100%, respectively. Positive predictive values and negative predictive values were different for all the tests. These differences results are controversial and therefore reliability and reproducibility of immunoassays as the only diagnostic method is questionable. The use of various Cryptosporidium species in diagnosis based on immunological testing and different results obtained by individual tests indicate potential differences in Copro-antigens produced by individual Cryptosporidium species. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Reward sensitivity predicts ice cream-related attentional bias assessed by inattentional blindness.

Science.gov (United States)

Li, Xiaoming; Tao, Qian; Fang, Ya; Cheng, Chen; Hao, Yangyang; Qi, Jianjun; Li, Yu; Zhang, Wei; Wang, Ying; Zhang, Xiaochu

2015-06-01

The cognitive mechanism underlying the association between individual differences in reward sensitivity and food craving is unknown. The present study explored the mechanism by examining the role of reward sensitivity in attentional bias toward ice cream cues. Forty-nine college students who displayed high level of ice cream craving (HICs) and 46 who displayed low level of ice cream craving (LICs) performed an inattentional blindness (IB) task which was used to assess attentional bias for ice cream. In addition, reward sensitivity and coping style were assessed by the Behavior Inhibition System/Behavior Activation System Scales and Simplified Coping Style Questionnaire. Results showed significant higher identification rate of the critical stimulus in the HICs than LICs, suggesting greater attentional bias for ice cream in the HICs. It was indicated that attentional bias for food cues persisted even under inattentional condition. Furthermore, a significant correlation was found between the attentional bias and reward sensitivity after controlling for coping style, and reward sensitivity predicted attentional bias for food cues. The mediation analyses showed that attentional bias mediated the relationship between reward sensitivity and food craving. Those findings suggest that the association between individual differences in reward sensitivity and food craving may be attributed to attentional bias for food-related cues. Copyright © 2015 Elsevier Ltd. All rights reserved.

Detecting fragmentation extinction thresholds for forest understory plant species in peninsular Spain.

Science.gov (United States)

Rueda, Marta; Moreno Saiz, Juan Carlos; Morales-Castilla, Ignacio; Albuquerque, Fabio S; Ferrero, Mila; Rodríguez, Miguel Á

2015-01-01

Ecological theory predicts that fragmentation aggravates the effects of habitat loss, yet empirical results show mixed evidences, which fail to support the theory instead reinforcing the primary importance of habitat loss. Fragmentation hypotheses have received much attention due to their potential implications for biodiversity conservation, however, animal studies have traditionally been their main focus. Here we assess variation in species sensitivity to forest amount and fragmentation and evaluate if fragmentation is related to extinction thresholds in forest understory herbs and ferns. Our expectation was that forest herbs would be more sensitive to fragmentation than ferns due to their lower dispersal capabilities. Using forest cover percentage and the proportion of this percentage occurring in the largest patch within UTM cells of 10-km resolution covering Peninsular Spain, we partitioned the effects of forest amount versus fragmentation and applied logistic regression to model occurrences of 16 species. For nine models showing robustness according to a set of quality criteria we subsequently defined two empirical fragmentation scenarios, minimum and maximum, and quantified species' sensitivity to forest contraction with no fragmentation, and to fragmentation under constant forest cover. We finally assessed how the extinction threshold of each species (the habitat amount below which it cannot persist) varies under no and maximum fragmentation. Consistent with their preference for forest habitats probability occurrences of all species decreased as forest cover contracted. On average, herbs did not show significant sensitivity to fragmentation whereas ferns were favored. In line with theory, fragmentation yielded higher extinction thresholds for two species. For the remaining species, fragmentation had either positive or non-significant effects. We interpret these differences as reflecting species-specific traits and conclude that although forest amount is of

Detecting fragmentation extinction thresholds for forest understory plant species in peninsular Spain.

Directory of Open Access Journals (Sweden)

Marta Rueda

Full Text Available Ecological theory predicts that fragmentation aggravates the effects of habitat loss, yet empirical results show mixed evidences, which fail to support the theory instead reinforcing the primary importance of habitat loss. Fragmentation hypotheses have received much attention due to their potential implications for biodiversity conservation, however, animal studies have traditionally been their main focus. Here we assess variation in species sensitivity to forest amount and fragmentation and evaluate if fragmentation is related to extinction thresholds in forest understory herbs and ferns. Our expectation was that forest herbs would be more sensitive to fragmentation than ferns due to their lower dispersal capabilities. Using forest cover percentage and the proportion of this percentage occurring in the largest patch within UTM cells of 10-km resolution covering Peninsular Spain, we partitioned the effects of forest amount versus fragmentation and applied logistic regression to model occurrences of 16 species. For nine models showing robustness according to a set of quality criteria we subsequently defined two empirical fragmentation scenarios, minimum and maximum, and quantified species' sensitivity to forest contraction with no fragmentation, and to fragmentation under constant forest cover. We finally assessed how the extinction threshold of each species (the habitat amount below which it cannot persist varies under no and maximum fragmentation. Consistent with their preference for forest habitats probability occurrences of all species decreased as forest cover contracted. On average, herbs did not show significant sensitivity to fragmentation whereas ferns were favored. In line with theory, fragmentation yielded higher extinction thresholds for two species. For the remaining species, fragmentation had either positive or non-significant effects. We interpret these differences as reflecting species-specific traits and conclude that although

Expression of UV-sensitive parapinopsin in the iguana parietal eyes and its implication in UV-sensitivity in vertebrate pineal-related organs.

Science.gov (United States)

Wada, Seiji; Kawano-Yamashita, Emi; Koyanagi, Mitsumasa; Terakita, Akihisa

2012-01-01

The pineal-related organs of lower vertebrates have the ability to discriminate different wavelengths of light. This wavelength discrimination is achieved through antagonistic light responses to UV or blue and visible light. Previously, we demonstrated that parapinopsin underlies the UV reception in the lamprey pineal organ and identified parapinopsin genes in teleosts and frogs of which the pineal-related organs were reported to discriminate light. In this study, we report the first identification of parapinopsin in the reptile lineage and show its expression in the parietal eye of the green iguana. Spectroscopic analysis revealed that iguana parapinopsin is a UV-sensitive pigment, similar to lamprey parapinopsin. Interestingly, immunohistochemical analyses using antibodies specific to parapinopsin and parietopsin, a parietal eye green-sensitive pigment, revealed that parapinopsin and parietopsin are colocalized in the outer segments of the parietal eye photoreceptor cells in iguanas. These results strongly suggest that parapinopsin underlies the wavelength discrimination involving UV reception in the iguana parietal eye. The current findings support the idea that parapinopsin is a common photopigment underlying the UV-sensitivity in wavelength discrimination of the pineal-related organs found from lampreys to reptiles.

Expression of UV-Sensitive Parapinopsin in the Iguana Parietal Eyes and Its Implication in UV-Sensitivity in Vertebrate Pineal-Related Organs

Science.gov (United States)

Wada, Seiji; Kawano-Yamashita, Emi; Koyanagi, Mitsumasa; Terakita, Akihisa

2012-01-01

The pineal-related organs of lower vertebrates have the ability to discriminate different wavelengths of light. This wavelength discrimination is achieved through antagonistic light responses to UV or blue and visible light. Previously, we demonstrated that parapinopsin underlies the UV reception in the lamprey pineal organ and identified parapinopsin genes in teleosts and frogs of which the pineal-related organs were reported to discriminate light. In this study, we report the first identification of parapinopsin in the reptile lineage and show its expression in the parietal eye of the green iguana. Spectroscopic analysis revealed that iguana parapinopsin is a UV-sensitive pigment, similar to lamprey parapinopsin. Interestingly, immunohistochemical analyses using antibodies specific to parapinopsin and parietopsin, a parietal eye green-sensitive pigment, revealed that parapinopsin and parietopsin are colocalized in the outer segments of the parietal eye photoreceptor cells in iguanas. These results strongly suggest that parapinopsin underlies the wavelength discrimination involving UV reception in the iguana parietal eye. The current findings support the idea that parapinopsin is a common photopigment underlying the UV-sensitivity in wavelength discrimination of the pineal-related organs found from lampreys to reptiles. PMID:22720013

Expression of UV-sensitive parapinopsin in the iguana parietal eyes and its implication in UV-sensitivity in vertebrate pineal-related organs.

Directory of Open Access Journals (Sweden)

Seiji Wada

Full Text Available The pineal-related organs of lower vertebrates have the ability to discriminate different wavelengths of light. This wavelength discrimination is achieved through antagonistic light responses to UV or blue and visible light. Previously, we demonstrated that parapinopsin underlies the UV reception in the lamprey pineal organ and identified parapinopsin genes in teleosts and frogs of which the pineal-related organs were reported to discriminate light. In this study, we report the first identification of parapinopsin in the reptile lineage and show its expression in the parietal eye of the green iguana. Spectroscopic analysis revealed that iguana parapinopsin is a UV-sensitive pigment, similar to lamprey parapinopsin. Interestingly, immunohistochemical analyses using antibodies specific to parapinopsin and parietopsin, a parietal eye green-sensitive pigment, revealed that parapinopsin and parietopsin are colocalized in the outer segments of the parietal eye photoreceptor cells in iguanas. These results strongly suggest that parapinopsin underlies the wavelength discrimination involving UV reception in the iguana parietal eye. The current findings support the idea that parapinopsin is a common photopigment underlying the UV-sensitivity in wavelength discrimination of the pineal-related organs found from lampreys to reptiles.

Heightened emotional sensitivity intensifies associations between relational aggression and victimization among girls but not boys: a longitudinal study.

Science.gov (United States)

Zimmer-Gembeck, Melanie J; Duffy, Amanda L

2014-08-01

Founded in the social process model, the aim of this study was to identify whether the associations of relational aggression with concurrent and subsequent relational victimization differed depending on early adolescents' personal vulnerabilities and gender. The vulnerabilities of interest were social-information processing variables that convey greater emotional sensitivity, including rejection sensitivity, fear of negative evaluation, and avoidance of intimacy. Participants were 358 early adolescents (176 boys, 178 girls) aged 9 to 13 years. Relational aggression and victimization were assessed via peer nominations, whereas the three indicators of emotional sensitivity were assessed via self-report. Overall, results revealed greater relational aggression at Time 1 to be associated with greater relational victimization at both Time 1 and Time 2. However, this finding was qualified by both emotional sensitivity and gender. When considered separately, girls who were relationally aggressive and emotionally sensitive were at increased risk of victimization at both assessment points. In contrast, no link was found between relational aggression and victimization for boys, although relational vulnerabilities did have unique associations with boys' relational victimization. These findings have implications for our understanding of relational aggression and victimization, as well as for the development of interventions aimed at reducing these problems.

Ionic liquid-assisted multiwalled carbon nanotube-dispersive micro-solid phase extraction for sensitive determination of inorganic As species in garlic samples by electrothermal atomic absorption spectrometry

Energy Technology Data Exchange (ETDEWEB)

Grijalba, Alexander Castro; Escudero, Leticia B.; Wuilloud, Rodolfo G., E-mail: rwuilloud@mendoza-conicet.gob.ar

2015-08-01

A highly sensitive dispersive micro-solid phase extraction (D-μ-SPE) method combining an ionic liquid (IL) and multi-walled carbon nanotubes (MWCNTs) for inorganic As species (As(III) and As(V)) species separation and determination in garlic samples by electrothermal atomic absorption spectrometry (ETAAS) was developed. Trihexyl(tetradecil)phosphonium chloride IL was used to form an ion pair with the arsenomolybdate complex obtained by reaction of As(V) with molybdate ion. Afterwards, 1.0 mg of MWCNTs was dispersed for As(V) extraction and the supernatant was separated by centrifugation. MWCNTs were re-dispersed with tetradecyltrimethylammonium bromide surfactant and ultrasound followed by direct injection into the graphite furnace of ETAAS for As determination. Pyrolysis and atomization conditions were carefully studied for complete decomposition of MWCNTs and IL matrices. Under optimum conditions, an extraction efficiency of 100% and a preconcentration factor of 70 were obtained with 5 mL of garlic extract. The detection limit was 7.1 ng L{sup −1} and the relative standard deviations (RSDs) for six replicate measurements at 5 μg L{sup −1} of As were 5.4% and 4.8% for As(III) and As(V), respectively. The proposed D-μ-SPE method allowed the efficient separation and determination of inorganic As species in a complex matrix such as garlic extract. - Highlights: • Efficient retention and preconcentration of As by combining an IL with MWCNTs • Determination of As by ETAAS with direct injection of MWCNTs • Thermal degradation of MWCNTs in the graphite furnace of ETAAS • Highly sensitive speciation and determination of As in garlic.

Ionic liquid-assisted multiwalled carbon nanotube-dispersive micro-solid phase extraction for sensitive determination of inorganic As species in garlic samples by electrothermal atomic absorption spectrometry

International Nuclear Information System (INIS)

Grijalba, Alexander Castro; Escudero, Leticia B.; Wuilloud, Rodolfo G.

2015-01-01

A highly sensitive dispersive micro-solid phase extraction (D-μ-SPE) method combining an ionic liquid (IL) and multi-walled carbon nanotubes (MWCNTs) for inorganic As species (As(III) and As(V)) species separation and determination in garlic samples by electrothermal atomic absorption spectrometry (ETAAS) was developed. Trihexyl(tetradecil)phosphonium chloride IL was used to form an ion pair with the arsenomolybdate complex obtained by reaction of As(V) with molybdate ion. Afterwards, 1.0 mg of MWCNTs was dispersed for As(V) extraction and the supernatant was separated by centrifugation. MWCNTs were re-dispersed with tetradecyltrimethylammonium bromide surfactant and ultrasound followed by direct injection into the graphite furnace of ETAAS for As determination. Pyrolysis and atomization conditions were carefully studied for complete decomposition of MWCNTs and IL matrices. Under optimum conditions, an extraction efficiency of 100% and a preconcentration factor of 70 were obtained with 5 mL of garlic extract. The detection limit was 7.1 ng L −1 and the relative standard deviations (RSDs) for six replicate measurements at 5 μg L −1 of As were 5.4% and 4.8% for As(III) and As(V), respectively. The proposed D-μ-SPE method allowed the efficient separation and determination of inorganic As species in a complex matrix such as garlic extract. - Highlights: • Efficient retention and preconcentration of As by combining an IL with MWCNTs • Determination of As by ETAAS with direct injection of MWCNTs • Thermal degradation of MWCNTs in the graphite furnace of ETAAS • Highly sensitive speciation and determination of As in garlic

Sensitive determination of iodine species, including organo-iodine, for freshwater and seawater samples using high performance liquid chromatography and spectrophotometric detection

International Nuclear Information System (INIS)

Schwehr, Kathleen A.; Santschi, Peter H.

2003-01-01

In order to more effectively use iodine isotope ratios, 129 I/ 127 I, as hydrological and geochemical tracers in aquatic systems, a new high performance liquid chromatography (HPLC) method was developed for the determination of iodine speciation. The dissolved iodine species that dominate natural water systems are iodide, iodate, and organic iodine. Using this new method, iodide was determined directly by combining anion exchange chromatography and spectrophotometry. Iodate and the total of organic iodine species are determined as iodide, with minimal sample preparation, compared to existing methods. The method has been applied to quantitatively determine iodide, iodate as the difference of total inorganic iodide and iodide after reduction of the sample by NaHSO 3 , and organic iodine as the difference of total iodide (after organic decomposition by dehydrohalogenation and reduction by NaHSO 3 ) and total inorganic iodide. Analytical accuracy was tested: (1) against certified reference material, SRM 1549, powdered milk (NIST); (2) through the method of standard additions; and (3) by comparison to values of environmental waters measured independently by inductively coupled plasma mass spectrometry (ICP-MS). The method has been successfully applied to measure the concentrations of iodide species in rain, surface and ground water, estuarine and seawater samples. The detection limit was ∼1 nM (0.2 ppb), with less than 3% relative standard deviation (R.S.D.) for samples determined by standard additions to an iodide solution of 20 nM in 0.1 M NaCl. This technique is one of the few methods sensitive enough to accurately quantify stable iodine species at nanomolar concentrations in aquatic systems across a range of matrices, and to quantitatively measure organic iodine. Additionally, this method makes use of a very dilute mobile phase, and may be applied to small sample volumes without pre-column concentration or post-column reactions

Examining anxiety sensitivity as an explanatory construct underlying HIV-related stigma: Relations to anxious arousal, social anxiety, and HIV symptoms among persons living with HIV.

Science.gov (United States)

Brandt, Charles P; Paulus, Daniel J; Jardin, Charles; Heggeness, Luke; Lemaire, Chad; Zvolensky, Michael J

2017-05-01

Persons living with HIV (PLHIV) are a health disparity subgroup of the overall population for mental and physical health problems. HIV-related stigma has been shown to increase anxiety symptoms and HIV symptoms among PLHIV. However, little is known about factors that may impact the relations between HIV-related stigma and anxiety symptoms and HIV symptoms among PLHIV. To address this gap in the literature, the current study examined anxiety sensitivity (i.e., the extent to which individuals believe anxiety and anxiety-related sensations) in the relation between HIV-related stigma, social anxiety, anxious arousal, and HIV symptoms among a sample of 87 PLHIV (60.9% cis gender male, 52.9% Black, non-Hispanic). Results indicated that anxiety sensitivity mediated the relations between HIV-related stigma and the dependent variables, with effect sizes indicating moderate to large effects of anxiety sensitivity on these relations. Findings suggest that anxiety sensitivity be a mechanistic factor in the relations between HIV-related stigma and social anxiety, anxious arousal, and HIV symptoms, and therefore, be important element in efforts to reduce mental/physical health disparity among this population. Copyright © 2016 Elsevier Ltd. All rights reserved.

Multilocus analysis of nucleotide variation and speciation in three closely related Populus (Salicaceae) species.

Science.gov (United States)

Du, Shuhui; Wang, Zhaoshan; Ingvarsson, Pär K; Wang, Dongsheng; Wang, Junhui; Wu, Zhiqiang; Tembrock, Luke R; Zhang, Jianguo

2015-10-01

Historical tectonism and climate oscillations can isolate and contract the geographical distributions of many plant species, and they are even known to trigger species divergence and ultimately speciation. Here, we estimated the nucleotide variation and speciation in three closely related Populus species, Populus tremuloides, P. tremula and P. davidiana, distributed in North America and Eurasia. We analysed the sequence variation in six single-copy nuclear loci and three chloroplast (cpDNA) fragments in 497 individuals sampled from 33 populations of these three species across their geographic distributions. These three Populus species harboured relatively high levels of nucleotide diversity and showed high levels of nucleotide differentiation. Phylogenetic analysis revealed that P. tremuloides diverged earlier than the other two species. The cpDNA haplotype network result clearly illustrated the dispersal route from North America to eastern Asia and then into Europe. Molecular dating results confirmed that the divergence of these three species coincided with the sundering of the Bering land bridge in the late Miocene and a rapid uplift of the Qinghai-Tibetan Plateau around the Miocene/Pliocene boundary. Vicariance-driven successful allopatric speciation resulting from historical tectonism and climate oscillations most likely played roles in the formation of the disjunct distributions and divergence of these three Populus species. © 2015 John Wiley & Sons Ltd.

Evaluation of species richness estimators based on quantitative performance measures and sensitivity to patchiness and sample grain size

Science.gov (United States)

Willie, Jacob; Petre, Charles-Albert; Tagg, Nikki; Lens, Luc

2012-11-01

Data from forest herbaceous plants in a site of known species richness in Cameroon were used to test the performance of rarefaction and eight species richness estimators (ACE, ICE, Chao1, Chao2, Jack1, Jack2, Bootstrap and MM). Bias, accuracy, precision and sensitivity to patchiness and sample grain size were the evaluation criteria. An evaluation of the effects of sampling effort and patchiness on diversity estimation is also provided. Stems were identified and counted in linear series of 1-m2 contiguous square plots distributed in six habitat types. Initially, 500 plots were sampled in each habitat type. The sampling process was monitored using rarefaction and a set of richness estimator curves. Curves from the first dataset suggested adequate sampling in riparian forest only. Additional plots ranging from 523 to 2143 were subsequently added in the undersampled habitats until most of the curves stabilized. Jack1 and ICE, the non-parametric richness estimators, performed better, being more accurate and less sensitive to patchiness and sample grain size, and significantly reducing biases that could not be detected by rarefaction and other estimators. This study confirms the usefulness of non-parametric incidence-based estimators, and recommends Jack1 or ICE alongside rarefaction while describing taxon richness and comparing results across areas sampled using similar or different grain sizes. As patchiness varied across habitat types, accurate estimations of diversity did not require the same number of plots. The number of samples needed to fully capture diversity is not necessarily the same across habitats, and can only be known when taxon sampling curves have indicated adequate sampling. Differences in observed species richness between habitats were generally due to differences in patchiness, except between two habitats where they resulted from differences in abundance. We suggest that communities should first be sampled thoroughly using appropriate taxon sampling

[DIFFERENTIAL SENSITIVITY OF MICROORGANISMS TO POLYHEXAMETHYLENEGUANIDINE].

Science.gov (United States)

Lysytsya, A V; Mandygra, Y M; Bojko, O P; Romanishyna, O O; Mandygra, M S

2015-01-01

Factors identified that affect the sensitivity of microorganisms to polyhexamethyleneguanidine (PHMG). Salts of PHMG chloride, valerate, maleate, succinate was to use. Test strains of Esherichia coli, Staphylococcus aureus, Bacillus cereus, Leptospira interrogans, Paenibacillus larvae, Mycobacterium bovis, M. avium, M. fortuitum, Aspergillus niger and some strains of viruses are taken as objects of research. We have determined that the cytoplasm membrane phospholipids is main "target" for the polycation molecules of PHMG. A differential sensitivity of the microorganisms to this drug is primarily determined by relative amount of lipids in membrane and their accessibility. Such trends exist: increase the relative contents of anionic lipids and more negative surface electric potential of membrane, and reduction of the sizes fat acid remainder of lipids bring to increase of microorganism sensitivity. Types of anion salt PHMG just have a certain value. Biocide activity of PHMG chloride is more, than its salts with organic acid. Feasibility of combining PHMG with other biocides in the multicomponent disinfectants studied and analyzed. This combination does not lead to a significant increase in the sensitivity of microorganisms tested in most cases. Most species of pathogenic bacteria can be quickly neutralized by aqueous solutions of PHMG in less than 1% concentrations.

A luciferase reporter gene assay and aryl hydrocarbon receptor 1 genotype predict the LD{sub 50} of polychlorinated biphenyls in avian species

Energy Technology Data Exchange (ETDEWEB)

Manning, Gillian E., E-mail: gmann017@uottawa.ca [Centre for Advanced Research in Environmental Genomics, Department of Biology, University of Ottawa, Ottawa, ON, Canada K1N 6N5 (Canada); Environment Canada, National Wildlife Research Centre, Ottawa, ON, Canada K1A 0H3 (Canada); Farmahin, Reza, E-mail: mfarm070@uottawa.ca [Centre for Advanced Research in Environmental Genomics, Department of Biology, University of Ottawa, Ottawa, ON, Canada K1N 6N5 (Canada); Environment Canada, National Wildlife Research Centre, Ottawa, ON, Canada K1A 0H3 (Canada); Crump, Doug, E-mail: doug.crump@ec.gc.ca [Environment Canada, National Wildlife Research Centre, Ottawa, ON, Canada K1A 0H3 (Canada); Jones, Stephanie P., E-mail: stephanie.jones@ec.gc.ca [Environment Canada, National Wildlife Research Centre, Ottawa, ON, Canada K1A 0H3 (Canada); Klein, Jeff, E-mail: jeffery@well-labs.com [Wellington Laboratories Inc., Research Division, Guelph, ON, Canada N1G 3M5 (Canada); Konstantinov, Alex, E-mail: alex@well-labs.com [Wellington Laboratories Inc., Research Division, Guelph, ON, Canada N1G 3M5 (Canada); Potter, Dave, E-mail: dpotter@well-labs.com [Wellington Laboratories Inc., Research Division, Guelph, ON, Canada N1G 3M5 (Canada); Kennedy, Sean W., E-mail: sean.kennedy@ec.gc.ca [Centre for Advanced Research in Environmental Genomics, Department of Biology, University of Ottawa, Ottawa, ON, Canada K1N 6N5 (Canada); Environment Canada, National Wildlife Research Centre, Ottawa, ON, Canada K1A 0H3 (Canada)

2012-09-15

Birds differ in sensitivity to the embryotoxic effects of polychlorinated biphenyls (PCBs), which complicates environmental risk assessments for these chemicals. Recent research has shown that the identities of amino acid residues 324 and 380 in the avian aryl hydrocarbon receptor 1 (AHR1) ligand binding domain (LBD) are primarily responsible for differences in avian species sensitivity to selected dibenzo-p-dioxins and furans. A luciferase reporter gene (LRG) assay was developed in our laboratory to measure AHR1-mediated induction of a cytochrome P450 1A5 reporter gene in COS-7 cells transfected with different avian AHR1 constructs. In the present study, the LRG assay was used to measure the concentration-dependent effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and PCBs 126, 77, 105 and 118 on luciferase activity in COS-7 cells transfected with AHR1 constructs representative of 86 avian species in order to predict their sensitivity to PCB-induced embryolethality and the relative potency of PCBs in these species. The results of the LRG assay indicate that the identity of amino acid residues 324 and 380 in the AHR1 LBD are the major determinants of avian species sensitivity to PCBs. The relative potency of PCBs did not differ greatly among AHR1 constructs. Luciferase activity was significantly correlated with embryolethality data obtained from the literature (R{sup 2} ≥ 0.87, p < 0.0001). Thus, the LRG assay in combination with the knowledge of a species' AHR1 LBD sequence can be used to predict PCB-induced embryolethality in potentially any avian species of interest without the use of lethal methods on a large number of individuals. -- Highlights: ► PCB embryolethality in birds can be predicted from a species' AHR1 genotype. ► The reporter gene assay is useful for predicting species sensitivity to PCBs. ► The relative potency of PCBs does not appear to differ between AHR1 genotypes. ► Contamination of PCB 105 and PCB 118 did not affect

Relative lack of regeneration of shade-intolerant canopy species in some South African forests

CSIR Research Space (South Africa)

Midgley, JJ

1995-01-01

Full Text Available Some species such as Celtis Africana, are experiencing relative recruitment bottlenecks, because there are usually fewer recruits [i.e. individuals <20 cm diameter at breast height, (dbh)] than canopy individuals. The species with low recruitment...

Determination of Irgarol-1051 and its related s-triazine species in coastal sediments and mussel tissues by HPLC-ESI-MS/MS.

Science.gov (United States)

Tsang, Vic Wing-Hang; Lei, Ngai-Yu; Lam, Michael Hon-Wah

2009-10-01

A mild, low-temperature analytical approach based on sonication assisted extraction coupled with HPLC electrospray ionization triple quadrupole tandem mass spectrometry has been developed for the simultaneous qualitative and quantitative determination of the four Irgarol-related s-triazine species, namely Irgarol-1051, M1, M2 and M3, in coastal sediments and Green-lipped mussel samples. Mild extraction conditions were necessary for the preservation of the thermally unstable M2. The Multiple Reaction Monitoring (MRM) mode of detection by ESI-MS/MS enabled reliable qualitative identification and sensitive quantitative determination of those s-triazines. This determination method was applied to evaluate the degree of Irgarol-1051 contamination in the sediments and biota of the coastal environment of Hong Kong--one of the busiest maritime ports in the world. All the four s-triazine species were observed in all of the samples. This is the first time that the newly identified M2 and M3 are detected in coastal sediments and biota tissues.

Contrasting extremes in water-related stresses determine species survival

Science.gov (United States)

Bartholomeus, R. P.; Witte, J. P. M.; van Bodegom, P. M.; van Dam, J. C.; Aerts, R.

2012-04-01

In temperate climates, soil moisture, in concert with nutrient availability and soil acidity, is the most important environmental filter in determining local plant species composition, as it determines the availability of both oxygen and water to plant roots. These resources are indispensable for meeting the physiological demands of plants. Especially the occurrence of both excessive dry and wet moisture conditions at a particular site has strong implications for the survival of species, because plants need traits that allow them to respond to such counteracting conditions. However, adapting to one stress may go at the cost of the other, i.e. there exists a trade-off in the tolerance for wet conditions and the tolerance for dry conditions. Until now, both large-scale (global) and plot-scale effects of soil moisture conditions on plant species composition have mostly been investigated through indirect environmental measures, which do not include the key soil physical and plant physiological processes in the soil-plant-atmosphere system. Moreover, researchers only determined effects of one of the water-related stresses, i.e. either oxygen or drought stress. In order to quantify both oxygen and drought stress with causal measures, we focused on interacting meteorological, soil physical, microbial, and plant physiological processes in the soil-plant-atmosphere system. We simulated these plant stresses with a novel, process-based approach, incorporating in detail the interacting processes in the soil-plant-atmosphere interface. High variability and extremes in resource availability can be highly detrimental to plant species ('you can only die once'). We show that co-occurrence of oxygen and drought stress reduces the percentage of specialists within a vegetation plot. The percentage of non-specialists within a vegetation plot, however, decreases significantly with increasing stress as long as only one of the stresses prevails, but increases significantly with an

Increased genetic divergence between two closely related fir species in areas of range overlap

Science.gov (United States)

Wang, Jing; Abbott, Richard J; Ingvarsson, Pär K; Liu, Jianquan

2014-01-01

Because of introgressive hybridization, closely related species can be more similar to each other in areas of range overlap (parapatry or sympatry) than in areas where they are geographically isolated from each other (allopatry). Here, we report the reverse situation based on nuclear genetic divergence between two fir species, Abies chensiensis and Abies fargesii, in China, at sites where they are parapatric relative to where they are allopatric. We examined genetic divergence across 126 amplified fragment length polymorphism (AFLP) markers in a set of 172 individuals sampled from both allopatric and parapatric populations of the two species. Our analyses demonstrated that AFLP divergence was much greater between the species when comparisons were made between parapatric populations than between allopatric populations. We suggest that selection in parapatry may have largely contributed to this increased divergence. PMID:24772279

Determination of Germination Response to Temperature and Water Potential for a Wide Range of Cover Crop Species and Related Functional Groups.

Science.gov (United States)

Tribouillois, Hélène; Dürr, Carolyne; Demilly, Didier; Wagner, Marie-Hélène; Justes, Eric

2016-01-01

A wide range of species can be sown as cover crops during fallow periods to provide various ecosystem services. Plant establishment is a key stage, especially when sowing occurs in summer with high soil temperatures and low water availability. The aim of this study was to determine the response of germination to temperature and water potential for diverse cover crop species. Based on these characteristics, we developed contrasting functional groups that group species with the same germination ability, which may be useful to adapt species choice to climatic sowing conditions. Germination of 36 different species from six botanical families was measured in the laboratory at eight temperatures ranging from 4.5-43°C and at four water potentials. Final germination percentages, germination rate, cardinal temperatures, base temperature and base water potential were calculated for each species. Optimal temperatures varied from 21.3-37.2°C, maximum temperatures at which the species could germinate varied from 27.7-43.0°C and base water potentials varied from -0.1 to -2.6 MPa. Most cover crops were adapted to summer sowing with a relatively high mean optimal temperature for germination, but some Fabaceae species were more sensitive to high temperatures. Species mainly from Poaceae and Brassicaceae were the most resistant to water deficit and germinated under a low base water potential. Species were classified, independent of family, according to their ability to germinate under a range of temperatures and according to their base water potential in order to group species by functional germination groups. These groups may help in choosing the most adapted cover crop species to sow based on climatic conditions in order to favor plant establishment and the services provided by cover crops during fallow periods. Our data can also be useful as germination parameters in crop models to simulate the emergence of cover crops under different pedoclimatic conditions and crop

[Resources of Lycium species and related research progress].

Science.gov (United States)

Dong, Jing-Zhou; Yang, Jun-Jun; Wang, Ying

2008-09-01

Solanaceae Lycium speices are deciduous shrubs. In ancient Chinese medicine works, Lycium plants are described to work well in nourshing liver and kidney, enhancing eyesight, enriching blood, invigorating sex, reducing rheumatism and so on. More of their functions such as immunity improvement, anti-oxydation, anti-aging, anti-cancer, growth stumulation, hemopoiesis enhancing, incretion regulating, blood sugar reducing, bearing improvement and many other new functions are conformed in modern clinic researches. Lycium is also widely used in brewing, beverage and many other products. The world Lycium-related researches are mostly on Lycium species genesis and evolution, sexual evolution, active ingredient separation and pharmacological effects. The future research direction is indicated in this article, molecular evolution and systematics rather than traditional taxonomy will do better in explanation of present global distribution of Lycium species; comparative genomics research on Lycium will be a whole new way to deep gene resources exploration; relationship of genetic diversity and active ingredient variation on L. barbarum and L. chinense will lay theory basis for new germplasm development, breeding, cultivation and production regionalization.

Chloroplast and mitochondrial microsatellites for Millettia pinnata (Fabaceae) and cross-amplification in related species.

Science.gov (United States)

Wang, Yanling; Xie, Hongxian; Yang, Yi; Huang, Yelin; Wang, Jianwu; Tan, Fengxiao

2017-05-01

Chloroplast and mitochondrial microsatellites were identified to study the population genetics of Millettia pinnata (Fabaceae). Based on publicly available plastid genome sequence data of M. pinnata , 42 primer pairs were developed, of which 17 displayed polymorphisms across 89 individuals from four populations. For chloroplast loci, two to six alleles were recovered and the unbiased haploid diversity per locus ranged from 0.391 to 0.857. For mitochondrial loci, two to four alleles were recovered and the unbiased haploid diversity ranged from 0.264 to 0.740. Sixteen of the 17 screened markers could be successfully amplified in the related species M. pulchra . The 17 microsatellite markers developed here exhibited variation in M. pinnata and 16 presented transferability in the related species M. pulchra , suggesting that these markers will be valuable for genetic studies across M. pinnata and its related species.

Kinesthetic sensitivity and related measures of hand sensitivity in children with nonproficient handwriting.

Science.gov (United States)

Brink, Anne O'Leary; Jacobs, Anne Burleigh

2011-01-01

This study compared measures of hand sensitivity and handwriting quality in children aged 10 to 12 years identified by their teachers as having nonproficient or proficient handwriting. We hypothesized that children with nonproficient handwriting have decreased kinesthetic sensitivity of the hands and digits. Sixteen subjects without documented motor or cognitive concerns were tested for kinesthetic sensitivity, discriminate tactile awareness, diadochokinesia, stereognosis, and graphesthesia. Eight children were considered to have nonproficient handwriting; 8 had proficient handwriting. Nonparametric Mann-Whitney U tests were used to identify differences between groups on sensory tests. The 2 groups showed a statistically significant difference in handwriting legibility (P = .018). No significant difference was found on tests of kinesthetic sensitivity or other measures of sensation. Children presenting with handwriting difficulty as the only complaint have similar sensitivity in hands and digits as those with proficient handwriting. Failure to detect differences may result from a small sample size.

Technique for Measuring Speed and Visual Motion Sensitivity in Lizards

Science.gov (United States)

Woo, Kevin L.; Burke, Darren

2008-01-01

Testing sensory characteristics on herpetological species has been difficult due to a range of properties related to physiology, responsiveness, performance ability, and the type of reinforcer used. Using the Jacky lizard as a model, we outline a successfully established procedure in which to test the visual sensitivity to motion characteristics.…

Responses of evergreen and deciduous Quercus species to enhanced ozone levels

International Nuclear Information System (INIS)

Calatayud, Vicent; Cervero, Julia; Calvo, Esperanza; Garcia-Breijo, Francisco-Jose; Reig-Arminana, Jose; Sanz, Maria Jose

2011-01-01

Plants of one evergreen oak (Quercus ilex) and three deciduous oaks (Q. faginea, with small leaves; Q. pyrenaica and Q. robur, with large leaves) were exposed both to filtered air and to enhanced ozone levels in Open-Top Chambers. Q. faginea and Q. pyrenaica were studied for the first time. Based on visible injury, gas exchange, chlorophyll content and biomass responses, Q. pyrenaica was the most sensitive species, and Q. ilex was the most tolerant, followed by Q. faginea. Functional leaf traits of the species were related to differences in sensitivity, while accumulated ozone flux via stomata (POD 1.6 ) partly contributed to the observed differences. For risk assessment of Mediterranean vegetation, the diversity of responses detected in this study should be taken into account, applying appropriate critical levels. - Ozone tolerance overlapped with leaf traits in four Quercus species.

Responses of evergreen and deciduous Quercus species to enhanced ozone levels

Energy Technology Data Exchange (ETDEWEB)

Calatayud, Vicent, E-mail: calatayud_viclor@gva.e [Instituto Universitario CEAM-UMH, Charles R. Darwin 14, Parc Tecnologic, 46980 Paterna, Valencia (Spain); Cervero, Julia; Calvo, Esperanza [Instituto Universitario CEAM-UMH, Charles R. Darwin 14, Parc Tecnologic, 46980 Paterna, Valencia (Spain); Garcia-Breijo, Francisco-Jose [Laboratorio de Anatomia e Histologia Vegetal ' Julio Iranzo' , Jardin Botanico, Universitat de Valencia, c/Quart 80, 46008 Valencia (Spain); Departamento de Ecosistemas Agroforestales, Escuela Tecnica Superior del Medio Rural y Enologia, Universidad Politecnica de Valencia, Avda. Blasco Ibanez 21, 46010 Valencia (Spain); Reig-Arminana, Jose [Departamento de Ecosistemas Agroforestales, Escuela Tecnica Superior del Medio Rural y Enologia, Universidad Politecnica de Valencia, Avda. Blasco Ibanez 21, 46010 Valencia (Spain); Sanz, Maria Jose [Instituto Universitario CEAM-UMH, Charles R. Darwin 14, Parc Tecnologic, 46980 Paterna, Valencia (Spain)

2011-01-15

Plants of one evergreen oak (Quercus ilex) and three deciduous oaks (Q. faginea, with small leaves; Q. pyrenaica and Q. robur, with large leaves) were exposed both to filtered air and to enhanced ozone levels in Open-Top Chambers. Q. faginea and Q. pyrenaica were studied for the first time. Based on visible injury, gas exchange, chlorophyll content and biomass responses, Q. pyrenaica was the most sensitive species, and Q. ilex was the most tolerant, followed by Q. faginea. Functional leaf traits of the species were related to differences in sensitivity, while accumulated ozone flux via stomata (POD{sub 1.6}) partly contributed to the observed differences. For risk assessment of Mediterranean vegetation, the diversity of responses detected in this study should be taken into account, applying appropriate critical levels. - Ozone tolerance overlapped with leaf traits in four Quercus species.

Photosynthetic capacity of tropical montane tree species in relation to leaf nutrients, successional strategy and growth temperature.

Science.gov (United States)

Dusenge, Mirindi Eric; Wallin, Göran; Gårdesten, Johanna; Niyonzima, Felix; Adolfsson, Lisa; Nsabimana, Donat; Uddling, Johan

2015-04-01

Photosynthetic capacity of tree leaves is typically positively related to nutrient content and little affected by changes in growth temperature. These relationships are, however, often poorly supported for tropical trees, for which interspecific differences may be more strongly controlled by within-leaf nutrient allocation than by absolute leaf nutrient content, and little is known regarding photosynthetic acclimation to temperature. To explore the influence of leaf nutrient status, successional strategy and growth temperature on the photosynthetic capacity of tropical trees, we collected data on photosynthetic, chemical and morphological leaf traits of ten tree species in Rwanda. Seven species were studied in a forest plantation at mid-altitude (~1,700 m), whereas six species were studied in a cooler montane rainforest at higher altitude (~2,500 m). Three species were common to both sites, and, in the montane rainforest, three pioneer species and three climax species were investigated. Across species, interspecific variation in photosynthetic capacity was not related to leaf nutrient content. Instead, this variation was related to differences in within-leaf nitrogen allocation, with a tradeoff between investments into compounds related to photosynthetic capacity (higher in pioneer species) versus light-harvesting compounds (higher in climax species). Photosynthetic capacity was significantly lower at the warmer site at 1,700 m altitude. We conclude that (1) within-leaf nutrient allocation is more important than leaf nutrient content per se in controlling interspecific variation in photosynthetic capacity among tree species in tropical Rwanda, and that (2) tropical montane rainforest species exhibit decreased photosynthetic capacity when grown in a warmer environment.

Relative abundance estimations of Chengal trees in a tropical rainforest by using modified canopy fractional cover (mCFC)

International Nuclear Information System (INIS)

Hassan, N

2014-01-01

Tree species composition estimations are important to sustain forest management. This study estimates relative abundance of useful timber tree species (chengal) using Hyperion EO-1 satellite data. For the estimation, modified Canopy Fractional Cover (mCFC) was developed using Canopy Fractional Cover (CFC). mCFC was more sensitive to estimate relative abundance of chengal trees rather than Mixture Tuned Matched Filtering (MTMF). Meanwhile, MTMF was more sensitive to estimate the relative abundance of undisturbed forest. Accuracy suggests that the mCFC model is better to explain relative abundance of chengal trees than MTMF. Therefore, it can be concluded that relative abundance of tree species extracted from Hyperion EO-1 satellite data using modified Canopy Fractional Cover is an obtrusive approach used for identifying tree species composition

Relation between sensitization and failures of welded joints at furnaces of Cienfuegos refinery

International Nuclear Information System (INIS)

Dominguez, H.; Menendez, C.M.; Sendoya, F.A.

1992-01-01

This work is concerned about the possible relation between sensitization and failures of welded joints at furnaces of Cienfuegos Refinery. This failures were detected in austenitic pipes by hydraulic testing. For determined the tendency to sensitization of heat affected zones (HAZ) of welded joints and piping, have been used standardized test methods AM and AMU (GOST 6032-89). In addition, the Electrochemical Potentiokinetic Reactivation (EPR) test was employed to quantity the tendency to intergranular corrosion. It was found that degree of sensitization was higher at HAZ and as a possible explanation is proposed the overheating during welding

DNA barcoding of recently diverged species: relative performance of matching methods.

Directory of Open Access Journals (Sweden)

Robin van Velzen

Full Text Available Recently diverged species are challenging for identification, yet they are frequently of special interest scientifically as well as from a regulatory perspective. DNA barcoding has proven instrumental in species identification, especially in insects and vertebrates, but for the identification of recently diverged species it has been reported to be problematic in some cases. Problems are mostly due to incomplete lineage sorting or simply lack of a 'barcode gap' and probably related to large effective population size and/or low mutation rate. Our objective was to compare six methods in their ability to correctly identify recently diverged species with DNA barcodes: neighbor joining and parsimony (both tree-based, nearest neighbor and BLAST (similarity-based, and the diagnostic methods DNA-BAR, and BLOG. We analyzed simulated data assuming three different effective population sizes as well as three selected empirical data sets from published studies. Results show, as expected, that success rates are significantly lower for recently diverged species (∼75% than for older species (∼97% (P<0.00001. Similarity-based and diagnostic methods significantly outperform tree-based methods, when applied to simulated DNA barcode data (P<0.00001. The diagnostic method BLOG had highest correct query identification rate based on simulated (86.2% as well as empirical data (93.1%, indicating that it is a consistently better method overall. Another advantage of BLOG is that it offers species-level information that can be used outside the realm of DNA barcoding, for instance in species description or molecular detection assays. Even though we can confirm that identification success based on DNA barcoding is generally high in our data, recently diverged species remain difficult to identify. Nevertheless, our results contribute to improved solutions for their accurate identification.

Differential water mite parasitism, phenoloxidase activity, and resistance to mites are unrelated across pairs of related damselfly species.

Directory of Open Access Journals (Sweden)

Julia J Mlynarek

Full Text Available Related host species often demonstrate differences in prevalence and/or intensity of infection by particular parasite species, as well as different levels of resistance to those parasites. The mechanisms underlying this interspecific variation in parasitism and resistance expression are not well understood. Surprisingly, few researchers have assessed relations between actual levels of parasitism and resistance to parasites seen in nature across multiple host species. The main goal of this study was to determine whether interspecific variation in resistance against ectoparasitic larval water mites either was predictive of interspecific variation in parasitism for ten closely related species of damselflies (grouped into five "species pairs", or was predicted by interspecific variation in a commonly used measure of innate immunity (total Phenoloxidase or potential PO activity. Two of five species pairs had interspecific differences in proportions of individuals resisting larval Arrenurus water mites, only one of five species pairs had species differences in prevalence of larval Arrenurus water mites, and another two of five species pairs showed species differences in mean PO activity. Within the two species pairs where species differed in proportion of individuals resisting mites the species with the higher proportion did not have correspondingly higher PO activity levels. Furthermore, the proportion of individuals resisting mites mirrored prevalence of parasitism in only one species pair. There was no interspecific variation in median intensity of mite infestation within any species pair. We conclude that a species' relative ability to resist particular parasites does not explain interspecific variation in parasitism within species pairs and that neither resistance nor parasitism is reflected by interspecific variation in total PO or potential PO activity.

Temporal-spatial dynamics in orthoptera in relation to nutrient availability and plant species richness.

Directory of Open Access Journals (Sweden)

Rob J J Hendriks

Full Text Available Nutrient availability in ecosystems has increased dramatically over the last century. Excess reactive nitrogen deposition is known to negatively impact plant communities, e.g. by changing species composition, biomass and vegetation structure. In contrast, little is known on how such impacts propagate to higher trophic levels. To evaluate how nitrogen deposition affects plants and herbivore communities through time, we used extensive databases of spatially explicit historical records of Dutch plant species and Orthoptera (grasshoppers and crickets, a group of animals that are particularly susceptible to changes in the C:N ratio of their resources. We use robust methods that deal with the unstandardized nature of historical databases to test whether nitrogen deposition levels and plant richness changes influence the patterns of richness change of Orthoptera, taking into account Orthoptera species functional traits. Our findings show that effects indeed also propagate to higher trophic levels. Differences in functional traits affected the temporal-spatial dynamics of assemblages of Orthoptera. While nitrogen deposition affected plant diversity, contrary to our expectations, we could not find a strong significant effect of food related traits. However we found that species with low habitat specificity, limited dispersal capacity and egg deposition in the soil were more negativly affected by nitrogen deposition levels. Despite the lack of significant effect of plant richness or food related traits on Orthoptera, the negative effects of nitrogen detected within certain trait groups (e.g. groups with limited disperse ability could be related to subtle changes in plant abundance and plant quality. Our results, however, suggest that the changes in soil conditions (where many Orthoptera species lay their eggs or other habitat changes driven by nitrogen have a stronger influence than food related traits. To fully evaluate the negative effects of nitrogen

Phylogeography and systematics of zebra mussels and related species.

Science.gov (United States)

Gelembiuk, Gregory W; May, Gemma E; Lee, Carol Eunmi

2006-04-01

The genus Dreissena includes two widespread and aggressive aquatic invaders, the zebra mussel, Dreissena polymorpha, and the quagga mussel, Dreissena bugensis. This genus evolved in the Ponto-Caspian Sea basin, characterized by dynamic instability over multiple timescales and a unique evolutionary environment that may predispose to invasiveness. The objectives of this study were to gain insights into the demographic history of Dreissena species in their endemic range, to reconstruct intraspecific phylogeographic relationships among populations, and to clarify systematics of the genus, using DNA sequences from the mitochondrial cytochrome oxidase I (COI) gene. We found four deeply diverged clades within this genus, with a basal split that approximately coincided with the Cretaceous-Tertiary boundary. Divergence events within the four base clades were much more recent, corresponding to geographically disjunct sets of populations, which might represent species complexes. Across all taxa, populations of Dreissena shared a common pattern of genetic signatures indicating historical population bottlenecks and expansions. Haplotype diversity was relatively low in Ponto-Caspian drainages relative to more stable tectonic lakes in Greece, Macedonia, and Turkey. The phylogeographic and demographic patterns in the endemic range of Dreissena might have resulted from vicariance events, habitat instability, and the high fecundity and passive dispersal of these organisms.

Hearing capacities and otolith size in two ophidiiform species (Ophidion rochei and Carapus acus).

Science.gov (United States)

Kéver, Loïc; Colleye, Orphal; Herrel, Anthony; Romans, Pascal; Parmentier, Eric

2014-07-15

Numerous studies have highlighted the diversity of fish inner ear morphology. However, the function of the shape, size and orientation of the different structures remains poorly understood. The saccule (otolithic endorgan) is considered to be the principal hearing organ in fishes and it has been hypothesized that sagitta (saccular otolith) shape and size affect hearing capacities: large sagittae are thought to increase sensitivity. The sagittae of many ophidiids and carapids occupy a large volume inside the neurocranium. Hence they are a good structure with which to test the size hypothesis. The main aim of this study was to investigate hearing capacities and inner ear morphology in two ophidiiform species: Ophidion rochei and Carapus acus. We used a multidisciplinary approach that combines dissections, μCT-scan examinations and auditory evoked potential techniques. Carapus acus and O. rochei sagittae have similar maximal diameters; both species have larger otoliths than many non-ophidiiform species, especially compared with the intra-neurocranium volume. Both species are sensitive to sounds up to 2100 Hz. Relative to the skull, O. rochei has smaller sagittae than the carapid, but better hearing capacities from 300 to 900 Hz and similar sensitivities at 150 Hz and from 1200 to 2100 Hz. Results show that hearing capacities of a fish species cannot be predicted only based on sagitta size. Larger otoliths (in size relative to the skull) may have evolved mainly for performing vestibular functions in fishes, especially those species that need to execute precise and complex movements. © 2014. Published by The Company of Biologists Ltd.

Mesocosm Community Response Sensitivities to Specific Conductivity Comprised of Different Major Ions

Science.gov (United States)

Traditional toxicity test assays have been used to evaluate the relative sensitivity to different major ion mixtures as a proxy for understanding what the response of aquatic species growing in their natural environment would be during exposure to specific conductivity stress ema...

75 FR 8053 - A Framework for Categorizing the Relative Vulnerability of Threatened and Endangered Species to...

Science.gov (United States)

2010-02-23

... EPA's policy to include all comments it receives in the public docket without change and to make the... Categorizing the Relative Vulnerability of Threatened and Endangered Species to Climate Change AGENCY... Framework for Categorizing the Relative Vulnerability of Threatened and Endangered Species to Climate Change...

Scaling local species-habitat relations to the larger landscape with a hierarchical spatial count model

Science.gov (United States)

Thogmartin, W.E.; Knutson, M.G.

2007-01-01

Much of what is known about avian species-habitat relations has been derived from studies of birds at local scales. It is entirely unclear whether the relations observed at these scales translate to the larger landscape in a predictable linear fashion. We derived habitat models and mapped predicted abundances for three forest bird species of eastern North America using bird counts, environmental variables, and hierarchical models applied at three spatial scales. Our purpose was to understand habitat associations at multiple spatial scales and create predictive abundance maps for purposes of conservation planning at a landscape scale given the constraint that the variables used in this exercise were derived from local-level studies. Our models indicated a substantial influence of landscape context for all species, many of which were counter to reported associations at finer spatial extents. We found land cover composition provided the greatest contribution to the relative explained variance in counts for all three species; spatial structure was second in importance. No single spatial scale dominated any model, indicating that these species are responding to factors at multiple spatial scales. For purposes of conservation planning, areas of predicted high abundance should be investigated to evaluate the conservation potential of the landscape in their general vicinity. In addition, the models and spatial patterns of abundance among species suggest locations where conservation actions may benefit more than one species. ?? 2006 Springer Science+Business Media B.V.

Wing pattern morphology of three closely related Melitaea (Lepidoptera, Nymphalidae species reveals highly inaccurate external morphology-based species identification

Directory of Open Access Journals (Sweden)

Jure Jugovic

2014-06-01

Full Text Available Wing morphology of the three closely related species of Melitaea – M. athalia (Rottemburg, 1775, M. aurelia (Nickerl, 1850 and M. britomartis Assmann, 1847 – co-occurring in the Balkans (SE Europe was investigated in detail through visual inspection, morphometric analysis and multivariate statistical analysis. Results are compared to recent phylogenetic studies, searching for concordant patterns and discrepancies between the two approaches. The morphology of the genitalic structures is also compared with the results of the other two approaches. The main conclusions are as follows: (1 small albeit significant differences in wing morphology exist among the three species and (2 while the structure of male genitalia and phylogenetic position of the three species are concordant, they are (3 in discordance with the wing morphology. The present study represents another example where identification based on external morphology would lead to highly unreliable determinations, hence identification based on phylogenetic studies and/or genitalia is strongly recommended not only for the three studied species but also more broadly within the genus. Furthermore, we show that some of the characters generally used in the identification of these three Melitaea species should be avoided in future.

CHEMICAL VAPOUR DEPOSITION FROM A RADIATION-SENSITIVE PRECURSOR

DEFF Research Database (Denmark)

2017-01-01

The present invention relates in one aspect to a method of depositing a thin film on a substrate by chemical vapour deposition (CVD) from a radiation-sensitive precursor substance. The method comprises the steps of: (i) placing the substrate in a reaction chamber of a CVD system; (ii) heating...... heating pulse followed by an idle period; (iii) during at least one of the idle periods, providing a pressure pulse of precursor substance inside the reaction chamber by feeding at least one precursor substance to the reaction chamber so as to establish a reaction partial pressure for thin film deposition...... is formed. According to a further aspect, the invention relates to a chemical vapour deposition (CVD) system for depositing a thin film onto a substrate using precursor substances containing at least one radiation sensitive species....

Emotion Dysregulation Mediates the Relation between Mindfulness and Rejection Sensitivity.

Science.gov (United States)

Velotti, Patrizia; Garofalo, Carlo; Bizzi, Fabiola

2015-09-01

The role of rejection sensitivity (RS; the tendency to anxiously expect, readily perceive, and overreact to implied or overt interpersonal rejection) in psychopathology has mainly been studied with regard to borderline personality disorder (BPD). In the present study, we first sought to extend previous evidence of heightened RS in a clinical group with psychiatric disorders other than BPD, when compared with a community sample. Then, we tested whether emotion dysregulation and mindfulness were associated with RS in both sample, further hypothesizing that emotion dysregulation would mediate the relation between mindfulness deficits and RS. We adopted a cross-sectional design involving 191 psychiatric patients and 277 community participants (total N=468). All participants completed the Rejection Sensitivity Questionnaire, the Five Facet Mindfulness Questionnaire, and the Difficulties in Emotion Regulation Scale. Our hypotheses were supported, with psychiatric patients reporting greater levels of rejection sensitivity and emotion dysregulation, and lower level of mindfulness. Mindfulness deficits and emotion dysregulation explained a significant amount of variance in RS, in both samples. Finally, bootstrap analyses revealed that mindfulness deficits played an indirect effect on RS through the mediating role of emotion dysregulation. In particular, two different patterns emerged. Among psychiatric patients, an impairment in the ability to assume a non-judgmental stance towards own thoughts and feelings was related to RS through the mediation of limited access to emotion regulation strategies. Conversely, in the community sample, overall emotion dysregulation mediated the effect of lack of attention and awareness for present activities and experience on RS. Longitudinal studies could help in delineating etiological models of RS, and the joint role of deficits in mindfulness and emotion regulation should inform treatment programs.

Mitochondrial Genome Analysis of Wild Rice (Oryza minuta) and Its Comparison with Other Related Species.

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Asaf, Sajjad; Khan, Abdul Latif; Khan, Abdur Rahim; Waqas, Muhammad; Kang, Sang-Mo; Khan, Muhammad Aaqil; Shahzad, Raheem; Seo, Chang-Woo; Shin, Jae-Ho; Lee, In-Jung

2016-01-01

Oryza minuta (Poaceae family) is a tetraploid wild relative of cultivated rice with a BBCC genome. O. minuta has the potential to resist against various pathogenic diseases such as bacterial blight (BB), white backed planthopper (WBPH) and brown plant hopper (BPH). Here, we sequenced and annotated the complete mitochondrial genome of O. minuta. The mtDNA genome is 515,022 bp, containing 60 protein coding genes, 31 tRNA genes and two rRNA genes. The mitochondrial genome organization and the gene content at the nucleotide level are highly similar (89%) to that of O. rufipogon. Comparison with other related species revealed that most of the genes with known function are conserved among the Poaceae members. Similarly, O. minuta mt genome shared 24 protein-coding genes, 15 tRNA genes and 1 ribosomal RNA gene with other rice species (indica and japonica). The evolutionary relationship and phylogenetic analysis revealed that O. minuta is more closely related to O. rufipogon than to any other related species. Such studies are essential to understand the evolutionary divergence among species and analyze common gene pools to combat risks in the current scenario of a changing environment.

Relational Stressors and Depressive Symptoms in Late Adolescence: Rejection Sensitivity as a Vulnerability

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Chango, Joanna M.; McElhaney, Kathleen Boykin; Allen, Joseph P.; Schad, Megan M.; Marston, Emily

2012-01-01

The role of rejection sensitivity as a critical diathesis moderating the link between adolescent relational stressors and depressive symptoms was examined using multi-method, multi-reporter data from a diverse community sample of 173 adolescents, followed from age 16 to 18. Relational stressors examined included emotional abuse, maternal behavior…

Molecular Diagnosis of Pathogenic Sporothrix Species

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Rodrigues, Anderson Messias; de Hoog, G. Sybren; de Camargo, Zoilo Pires

2015-01-01

Background Sporotrichosis is a chronic (sub)cutaneous infection caused by thermodimorphic fungi in the order, Ophiostomatales. These fungi are characterized by major differences in routes of transmission, host predilections, species virulence, and susceptibilities to antifungals. Sporothrix species emerge in the form of outbreaks. Large zoonoses and sapronoses are ongoing in Brazil and China, respectively. Current diagnostic methods based on morphology and physiology are inaccurate due to closely related phenotypes with overlapping components between pathogenic and non-pathogenic Sporothrix. There is a critical need for new diagnostic tools that are specific, sensitive, and cost-effective. Methodology We developed a panel of novel markers, based on calmodulin (CAL) gene sequences, for the large-scale diagnosis and epidemiology of clinically relevant members of the Sporothrix genus, and its relative, Ophiostoma. We identified specific PCR-based markers for S. brasiliensis, S. schenckii, S. globosa, S. mexicana, S. pallida, and O. stenoceras. We employed a murine model of disseminated sporotrichosis to optimize a PCR assay for detecting Sporothrix in clinical specimens. Results Primer-BLAST searches revealed candidate sequences that were conserved within a single species. Species-specific primers showed no significant homology with human, mouse, or microorganisms outside the Sporothrix genus. The detection limit was 10–100 fg of DNA in a single round of PCR for identifying S. brasiliensis, S. schenckii, S. globosa, S. mexicana, and S. pallida. A simple, direct PCR assay, with conidia as a source of DNA, was effective for rapid, low-cost genotyping. Samples from a murine model of disseminated sporotrichosis confirmed the feasibility of detecting S. brasiliensis and S. schenckii DNA in spleen, liver, lungs, heart, brain, kidney, tail, and feces of infected animals. Conclusions This PCR-based method could successfully detect and identify a single species in samples

Incorporating evolutionary insights to improve ecotoxicology for freshwater species

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Brady, Steven P.; Richardson, Jonathan L.; Kunz, Bethany K.

2017-01-01

Ecotoxicological studies have provided extensive insights into the lethal and sublethal effects of environmental contaminants. These insights are critical for environmental regulatory frameworks, which rely on knowledge of toxicity for developing policies to manage contaminants. While varied approaches have been applied to ecotoxicological questions, perspectives related to the evolutionary history of focal species or populations have received little consideration. Here, we evaluate chloride toxicity from the perspectives of both macroevolution and contemporary evolution. First, by mapping chloride toxicity values derived from the literature onto a phylogeny of macroinvertebrates, fish, and amphibians, we tested whether macroevolutionary relationships across species and taxa are predictive of chloride tolerance. Next, we conducted chloride exposure tests for two amphibian species to assess whether potential contemporary evolutionary change associated with environmental chloride contamination influences chloride tolerance across local populations. We show that explicitly evaluating both macroevolution and contemporary evolution can provide important and even qualitatively different insights from those obtained via traditional ecotoxicological studies. While macroevolutionary perspectives can help forecast toxicological end points for species with untested sensitivities, contemporary evolutionary perspectives demonstrate the need to consider the environmental context of exposed populations when measuring toxicity. Accounting for divergence among populations of interest can provide more accurate and relevant information related to the sensitivity of populations that may be evolving in response to selection from contaminant exposure. Our data show that approaches accounting for and specifically examining variation among natural populations should become standard practice in ecotoxicology.

High diversity in neuropeptide immunoreactivity patterns among three closely related species of Dinophilidae (Annelida)

DEFF Research Database (Denmark)

Kerbl, Alexandra; Conzelmann, Markus; Jékely, Gáspár

2017-01-01

Neuropeptides are conserved metazoan signaling molecules, and represent useful markers for comparative investigations on the morphology and function of the nervous system. However, little is known about the variation of neuropeptide expression patterns across closely related species in invertebrate...... groups other than insects. In this study, we compare the immunoreactivity patterns of 14 neuropeptides in three closely related microscopic dinophilid annelids (Dinophilus gyrociliatus, D. taeniatus and Trilobodrilus axi). The brains of all three species were found to consist of around 700 somata...... species. FMRFamide, MLD/pedal peptide, allatotropin, RNamide, excitatory peptide, and FVRIamide showed a broad localization within the brain, while calcitonin, SIFamide, vasotocin, RGWamide, DLamide, FLamide, FVamide, MIP, and serotonin were present in fewer cells in demarcated regions. The different...

Relating hyporheic fluxes, residence times, and redox-sensitive biogeochemical processes upstream of beaver dams

Science.gov (United States)

Briggs, Martin A.; Lautz, Laura; Hare, Danielle K.

2013-01-01

Abstract. Small dams enhance the development of patchy microenvironments along stream corridors by trapping sediment and creating complex streambed morphologies. This patchiness drives intricate hyporheic flux patterns that govern the exchange of O2 and redox-sensitive solutes between the water column and the stream bed. We used multiple tracer techniques, naturally occurring and injected, to evaluate hyporheic flow dynamics and associated biogeochemical cycling and microbial reactivity around 2 beaver dams in Wyoming (USA). High-resolution fiber-optic distributed temperature sensing was used to collect temperature data over 9 vertical streambed profiles and to generate comprehensive vertical flux maps using 1-dimensional (1-D) heat-transport modeling. Coincident with these locations, vertical profiles of hyporheic water were collected every week and analyzed for dissolved O2, pH, dissolved organic C, and several conservative and redox-sensitive solutes. In addition, hyporheic and net stream aerobic microbial reactivity were analyzed with a constant-rate injection of the biologically sensitive resazurin (Raz) smart tracer. The combined results revealed a heterogeneous system with rates of downwelling hyporheic flow organized by morphologic unit and tightly coupled to the redox conditions of the subsurface. Principal component analysis was used to summarize the variability of all redox-sensitive species, and results indicated that hyporheic water varied from oxic-stream-like to anoxic-reduced in direct response to the hydrodynamic conditions and associated residence times. The anaerobic transition threshold predicted by the mean O2 Damko

Flowering time of butterfly nectar food plants is more sensitive to temperature than the timing of butterfly adult flight.

Science.gov (United States)

Kharouba, Heather M; Vellend, Mark

2015-09-01

1. Variation among species in their phenological responses to temperature change suggests that shifts in the relative timing of key life cycle events between interacting species are likely to occur under climate warming. However, it remains difficult to predict the prevalence and magnitude of these shifts given that there have been few comparisons of phenological sensitivities to temperature across interacting species. 2. Here, we used a broad-scale approach utilizing collection records to compare the temperature sensitivity of the timing of adult flight in butterflies vs. flowering of their potential nectar food plants (days per °C) across space and time in British Columbia, Canada. 3. On average, the phenology of both butterflies and plants advanced in response to warmer temperatures. However, the two taxa were differentially sensitive to temperature across space vs. across time, indicating the additional importance of nontemperature cues and/or local adaptation for many species. 4. Across butterfly-plant associations, flowering time was significantly more sensitive to temperature than the timing of butterfly flight and these sensitivities were not correlated. 5. Our results indicate that warming-driven shifts in the relative timing of life cycle events between butterflies and plants are likely to be prevalent, but that predicting the magnitude and direction of such changes in particular cases is going to require detailed, fine-scale data. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.

Relative abundance estimations of chengal tree in a tropical rainforest by using modified Canopy Fractional Cover (mCFC)

International Nuclear Information System (INIS)

Hassan, N

2014-01-01

Tree species composition estimations are important to sustain forest management. This study challenged estimates of relative abundance of useful timber tree species (chengal) using Hyperion EO-1 satellite data. For the estimation, modified Canopy Fractional Cover (mCFC) was developed using Canopy Fractional Cover (CFC). mCFC was more sensitive to estimate relative abundance of chengal trees rather than Mixture Tuned Matched Filtering (MTMF). Meanwhile, MTMF was more sensitive to estimate the relative abundance of undisturbed forest. Accuracy suggests that the mCFC model is better to explain relative abundance of chengal trees than MTMF. Therefore, it can be concluded that relative abundance of trees species extracted from Hyperion EO-1 satellite data using modified Canopy Fractional Cover is an obtrusive approach used for identifying trees species composition

Threatened and endangered wildlife species of the Hanford Site related to CERCLA characterization activities

Energy Technology Data Exchange (ETDEWEB)

Fitzner, R.E. [Pacific Northwest Lab., Richland, WA (United States); Weiss, S.G.; Stegen, J.A. [Westinghouse Hanford Co., Richland, WA (United States)

1994-06-01

The US Department of Energy`s (DOE) Hanford Site has been placed on the National Priorities List, which requires that it be remediated under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) or Superfund. Potentially contaminated areas of the Hanford Site were grouped into operable units, and detailed characterization and investigation plans were formulated. The DOE Richland Operations Office requested Westinghouse Hanford Company (WHC) to conduct a biological assessment of the potential impact of these characterization activities on the threatened, endangered, and sensitive wildlife species of the Hanford Site. Additional direction for WHC compliances with wildlife protection can be found in the Environmental Compliance Manual. This document is intended to meet these requirements, in part, for the CERCLA characterization activities, as well as for other work comparable in scope. This report documents the biological assessment and describes the pertinent components of the Hanford Site as well as the planned characterization activities. Also provided are accounts of endangered, threatened, and federal candidate wildlife species on the Hanford Site and information as to how human disturbances can affect these species. Potential effects of the characterization activities are described with recommendations for mitigation measures.

Visual resolution and contrast sensitivity in two benthic sharks.

Science.gov (United States)

Ryan, Laura A; Hart, Nathan S; Collin, Shaun P; Hemmi, Jan M

2016-12-15

Sharks have long been described as having 'poor' vision. They are cone monochromats and anatomical estimates suggest they have low spatial resolution. However, there are no direct behavioural measurements of spatial resolution or contrast sensitivity. This study estimates contrast sensitivity and spatial resolution of two species of benthic sharks, the Port Jackson shark, Heterodontus portusjacksoni, and the brown-banded bamboo shark, Chiloscyllium punctatum, by recording eye movements in response to optokinetic stimuli. Both species tracked moving low spatial frequency gratings with weak but consistent eye movements. Eye movements ceased at 0.38 cycles per degree, even for high contrasts, suggesting low spatial resolution. However, at lower spatial frequencies, eye movements were elicited by low contrast gratings, 1.3% and 2.9% contrast in H portusjacksoni and C. punctatum, respectively. Contrast sensitivity was higher than in other vertebrates with a similar spatial resolving power, which may reflect an adaptation to the relatively low contrast encountered in aquatic environments. Optokinetic gain was consistently low and neither species stabilised the gratings on their retina. To check whether restraining the animals affected their optokinetic responses, we also analysed eye movements in free-swimming C. punctatum We found no eye movements that could compensate for body rotations, suggesting that vision may pass through phases of stabilisation and blur during swimming. As C. punctatum is a sedentary benthic species, gaze stabilisation during swimming may not be essential. Our results suggest that vision in sharks is not 'poor' as previously suggested, but optimised for contrast detection rather than spatial resolution. © 2016. Published by The Company of Biologists Ltd.

Differences in mating strategies in two closely related small ermine moth species (Lepidoptera: Yponomeutidae)

NARCIS (Netherlands)

Bakker, A.C.; van Ginkel, W.E.; Roessingh, P.; Menken, S.B.J.

2008-01-01

The degree of polyandry in a species is linked to other life history traits such as egg maturation, life span, and male ejaculate size and quality. The study of differences in mating strategies between closely related species can provide a better understanding of the evolution of these strategies

Relative Prevalence of Grapevine Leafroll-Associated Virus Species in Wine Grape-Growing Regions of California.

Directory of Open Access Journals (Sweden)

Abhineet M Sharma

Full Text Available Some diseases manifest as one characteristic set of symptoms to the host, but can be caused by multiple pathogens. Control treatments based on plant symptoms can make it difficult to effectively manage such diseases, as the biology of the underlying pathogens can vary. Grapevine leafroll disease affects grapes worldwide, and is associated with several viral species in the family Closteroviridae. Whereas some of the viruses associated with this disease are transmitted by insect vectors, others are only graft-transmissible. In three regions of California, we surveyed vineyards containing diseased vines and screened symptomatic plants for all known viral species associated with grapevine leafroll disease. Relative incidence of each virus species differed among the three regions regions, particularly in relation to species with known vectors compared with those only known to be graft-transmitted. In one region, the pathogen population was dominated by species not known to have an insect vector. In contrast, populations in the other surveyed regions were dominated by virus species that are vector-transmissible. Our survey did not detect viruses associated with grapevine leafroll disease at some sites with characteristic disease symptoms. This could be explained either by undescribed genetic diversity among these viruses that prevented detection with available molecular tools at the time the survey was performed, or a misidentification of visual symptoms that may have had other underlying causes. Based on the differences in relative prevalence of each virus species among regions and among vineyards within regions, we expect that region and site-specific management strategies are needed for effective disease control.

Species composition of a soil invertebrate multi-species test system determines the level of ecotoxicity

International Nuclear Information System (INIS)

Sechi, Valentina; D'Annibale, Alessandra; Maraldo, Kristine; Johansen, Anders; Bossi, Rossana; Jensen, John; Krogh, Paul Henning

2014-01-01

A soil multi-species, SMS, experimental test system consisting of the natural microbial community, five collembolan species and a predatory mite along with either Enchytraeus crypticus or the earthworm Eisenia fetida were exposed to α-cypermethrin. A comparison of the performance of these two types of SMSs is given to aid the development of a standard test system. E. fetida had a positive effect on the majority of the species, reducing the negative insecticide effect. E. fetida affected the species sensitivity and decreased the degradation of the insecticide due to the organic matter incorporation of earthworm food. After 8 weeks, the EC50 was 0.76 mg kg −1 for enchytraeids and ranged between 2.7 and 18.9 mg kg −1 for collembolans, more sensitive than previously observed with single species. Changes observed in the community structure and function illustrates the strength of a multi-species test system as an ecotoxicological tool compared to single species tests. -- Highlights: • Degradation of alpha-cypermethrin was faster with enchytraeids than with earthworms. • Lumbricid castings and bioturbation explains bioavailability of α-cypermethrin. • Pesticide effects on soil arthropods alter with the community composition. • Multispecies test systems are feasible with either an enchytraeid or a lumbricid. • Collembolans are more sensitive to cypermethrin with enchytraeids than with earthworms. -- Soil ecotoxicological fate and effects in multispecies test systems are affected by earthworm activity

Advances in radiation biology: Relative radiation sensitivities of human organ systems. Volume 12

International Nuclear Information System (INIS)

Lett, J.T.; Altman, K.I.; Ehmann, U.K.; Cox, A.B.

1987-01-01

This volume is a thematically focused issue of Advances in Radiation Biology. The topic surveyed is relative radiosensitivity of human organ systems. Topics considered include relative radiosensitivities of the thymus, spleen, and lymphohemopoietic systems; relative radiosensitivities of the small and large intestine; relative rediosensitivities of the oral cavity, larynx, pharynx, and esophagus; relative radiation sensitivity of the integumentary system; dose response of the epidermal; microvascular, and dermal populations; relative radiosensitivity of the human lung; relative radiosensitivity of fetal tissues; and tolerance of the central and peripheral nervous system to therapeutic irradiation

Advances in radiation biology: Relative radiation sensitivities of human organ systems. Volume 12

Energy Technology Data Exchange (ETDEWEB)

Lett, J.T.; Altman, K.I.; Ehmann, U.K.; Cox, A.B.

1987-01-01

This volume is a thematically focused issue of Advances in Radiation Biology. The topic surveyed is relative radiosensitivity of human organ systems. Topics considered include relative radiosensitivities of the thymus, spleen, and lymphohemopoietic systems; relative radiosensitivities of the small and large intestine; relative rediosensitivities of the oral cavity, larynx, pharynx, and esophagus; relative radiation sensitivity of the integumentary system; dose response of the epidermal; microvascular, and dermal populations; relative radiosensitivity of the human lung; relative radiosensitivity of fetal tissues; and tolerance of the central and peripheral nervous system to therapeutic irradiation.

Diagnosis of gluten related disorders: Celiac disease, wheat allergy and non-celiac gluten sensitivity.

Science.gov (United States)

Elli, Luca; Branchi, Federica; Tomba, Carolina; Villalta, Danilo; Norsa, Lorenzo; Ferretti, Francesca; Roncoroni, Leda; Bardella, Maria Teresa

2015-06-21

Cereal crops and cereal consumption have had a vital role in Mankind's history. In the recent years gluten ingestion has been linked with a range of clinical disorders. Gluten-related disorders have gradually emerged as an epidemiologically relevant phenomenon with an estimated global prevalence around 5%. Celiac disease, wheat allergy and non-celiac gluten sensitivity represent different gluten-related disorders. Similar clinical manifestations can be observed in these disorders, yet there are peculiar pathogenetic pathways involved in their development. Celiac disease and wheat allergy have been extensively studied, while non-celiac gluten sensitivity is a relatively novel clinical entity, believed to be closely related to other gastrointestinal functional syndromes. The diagnosis of celiac disease and wheat allergy is based on a combination of findings from the patient's clinical history and specific tests, including serology and duodenal biopsies in case of celiac disease, or laboratory and functional assays for wheat allergy. On the other hand, non-celiac gluten sensitivity is still mainly a diagnosis of exclusion, in the absence of clear-cut diagnostic criteria. A multimodal pragmatic approach combining findings from the clinical history, symptoms, serological and histological tests is required in order to reach an accurate diagnosis. A thorough knowledge of the differences and overlap in clinical presentation among gluten-related disorders, and between them and other gastrointestinal disorders, will help clinicians in the process of differential diagnosis.

An analysis of sensitivity of CLIMEX parameters in mapping species potential distribution and the broad-scale changes observed with minor variations in parameters values: an investigation using open-field Solanum lycopersicum and Neoleucinodes elegantalis as an example

Science.gov (United States)

da Silva, Ricardo Siqueira; Kumar, Lalit; Shabani, Farzin; Picanço, Marcelo Coutinho

2018-04-01

A sensitivity analysis can categorize levels of parameter influence on a model's output. Identifying parameters having the most influence facilitates establishing the best values for parameters of models, providing useful implications in species modelling of crops and associated insect pests. The aim of this study was to quantify the response of species models through a CLIMEX sensitivity analysis. Using open-field Solanum lycopersicum and Neoleucinodes elegantalis distribution records, and 17 fitting parameters, including growth and stress parameters, comparisons were made in model performance by altering one parameter value at a time, in comparison to the best-fit parameter values. Parameters that were found to have a greater effect on the model results are termed "sensitive". Through the use of two species, we show that even when the Ecoclimatic Index has a major change through upward or downward parameter value alterations, the effect on the species is dependent on the selection of suitability categories and regions of modelling. Two parameters were shown to have the greatest sensitivity, dependent on the suitability categories of each species in the study. Results enhance user understanding of which climatic factors had a greater impact on both species distributions in our model, in terms of suitability categories and areas, when parameter values were perturbed by higher or lower values, compared to the best-fit parameter values. Thus, the sensitivity analyses have the potential to provide additional information for end users, in terms of improving management, by identifying the climatic variables that are most sensitive.

Comparative toxicity of imidacloprid and thiacloprid to different species of soil invertebrates.

Science.gov (United States)

de Lima E Silva, Cláudia; Brennan, Nicola; Brouwer, Jitske M; Commandeur, Daniël; Verweij, Rudo A; van Gestel, Cornelis A M

2017-05-01

Neonicotinoid insecticides have come under increasing scrutiny for their impact on non-target organisms, especially pollinators. The current scientific literature is mainly focused on the impact of these insecticides on pollinators and some aquatic insects, leaving a knowledge gap concerning soil invertebrates. This study aimed at filling this gap, by determining the toxicity of imidacloprid and thiacloprid to five species of soil invertebrates: earthworms (Eisenia andrei), enchytraeids (Enchytraeus crypticus), Collembola (Folsomia candida), oribatid mites (Oppia nitens) and isopods (Porcellio scaber). Tests focused on survival and reproduction or growth, after 3-5 weeks exposure in natural LUFA 2.2 standard soil. Imidacloprid was more toxic than thiacloprid for all species tested. F. candida and E. andrei were the most sensitive species, with LC 50 s of 0.20-0.62 and 0.77 mg/kg dry soil for imidacloprid and 2.7-3.9 and 7.1 mg/kg dry soil for thiacloprid. EC 50 s for effects on the reproduction of F. candida and E. andrei were 0.097-0.30 and 0.39 mg/kg dry soil for imidacloprid and 1.7-2.4 and 0.44 mg/kg dry soil for thiacloprid. The least sensitive species were O. nitens and P. scaber. Enchytraeids were a factor of 5-40 less sensitive than the taxonomically related earthworm, depending on the endpoint considered. Although not all the species showed high sensitivity to the neonicotinoids tested, these results raise awareness about the effects these insecticides can have on non-target soil invertebrates.

Secondary metabolites characteristic of Penicillium citrinum, Penicillium steckii and related species

DEFF Research Database (Denmark)

Malmstrom, J.; Christophersen, C.; Frisvad, Jens Christian

2000-01-01

an unidentified tunicate. The carboxylic acids and the benzopyran were identified on the basis of mass spectrometry, and one and two dimensional NMR spectroscopic techniques. The structures 1 and 2 resemble tanzawaic acid A-D, previously isolated from Penicillium citrinum. Screening of isolates of species related...

The Relations Among Threatened Species, Their Protection, and Taboos

Directory of Open Access Journals (Sweden)

Johan Colding

1997-06-01

Full Text Available We analyzed the role of taboos for the protection of species listed as "threatened" by the World Conservation Union (IUCN, and also for species known to be endemic and keystone. The study was limited to taboos that totally avoid or prohibit any use of particular species and their populations. We call them specific-species taboos . Through a literature review, 70 currently existing examples of specific-species taboos were identified and analyzed. The species avoided were grouped into biological classes. Threat categories were determined for each species, based on the IUCN Red Data Book. We found that ~ 30% of the identified taboos prohibit any use of species listed as threatened by IUCN. Of the specific-species taboos, 60% are set on reptiles and mammals. In these two classes, ~ 50% of the species are threatened, representing all of the threatened species in our analysis, with the exception of one bird species. Both endemic and keystone species that are important for ecosystem functions are avoided by specific-species taboos. Specific-species taboos have important ecological ramifications for the protection of threatened and ecologically important populations of species. We do not suggest that specific-species taboos are placed on species because they are, or have been, endangered; instead, we emphasize that species are avoided for a variety of other reasons. It is urgent to identify and analyze resource practices and social mechanisms of traditional societies, such as taboos, and to investigate their possible ecological significance. Although it may provide insights of value for conservation, not only of species, but also of ecosystem processes and functions, such information is being lost rapidly.

Site- and Species-Specific Influences on Sub-Alpine Conifer Growth in Mt. Rainier National Park, USA

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Myesa Legendre-Fixx

2017-12-01

Full Text Available Identifying the factors that influence the climate sensitivity of treeline species is critical to understanding carbon sequestration, forest dynamics, and conservation in high elevation forest/meadow ecotones. Using tree cores from four sub-alpine conifer species collected from three sides of Mt. Rainier, WA, USA, we investigated the influences of species identity and sites with different local climates on radial growth–climate relationships. We created chronologies for each species at each site, determined influential plant-relevant annual and seasonal climatic variables influencing growth, and investigated how the strength of climate sensitivity varied across species and location. Overall, similar climate variables constrained growth on all three sides of the mountain for each of the four study species. Summer warmth positively influenced radial growth, whereas snow, spring warmth, previous summer warmth, and spring humidity negatively influenced growth. We discovered only a few subtle differences in the climate sensitivity of co-occurring species at the same site and between the same species at different sites in pairwise comparisons. A model including species by climate interactions provided the best balance between parsimony and fit, but did not lead to substantially greater predictive power relative to a model without site or species interactions. Our results imply that at treeline in moist temperate regions like Mt. Rainier, the same climatic variables drive annual variation in growth across species and locations, despite species differences in physiology and site differences in mean climates.

Molecular detection and species-specific identification of medically important Aspergillus species by real-time PCR in experimental invasive pulmonary aspergillosis.

Science.gov (United States)

Walsh, Thomas J; Wissel, Mark C; Grantham, Kevin J; Petraitiene, Ruta; Petraitis, Vidmantas; Kasai, Miki; Francesconi, Andrea; Cotton, Margaret P; Hughes, Johanna E; Greene, Lora; Bacher, John D; Manna, Pradip; Salomoni, Martin; Kleiboeker, Steven B; Reddy, Sushruth K

2011-12-01

Diagnosis of invasive pulmonary aspergillosis (IPA) remains a major challenge to clinical microbiology laboratories. We developed rapid and sensitive quantitative PCR (qPCR) assays for genus- and species-specific identification of Aspergillus infections by use of TaqMan technology. In order to validate these assays and understand their potential diagnostic utility, we then performed a blinded study of bronchoalveolar lavage (BAL) fluid specimens from well-characterized models of IPA with the four medically important species. A set of real-time qPCR primers and probes was developed by utilizing unique ITS1 regions for genus- and species-specific detection of the four most common medically important Aspergillus species (Aspergillus fumigatus, A. flavus, A. niger, and A. terreus). Pan-Aspergillus and species-specific qPCRs with BAL fluid were more sensitive than culture for detection of IPA caused by A. fumigatus in untreated (P < 0.0007) and treated (P ≤ 0.008) animals, respectively. For infections caused by A. terreus and A. niger, culture and PCR amplification from BAL fluid yielded similar sensitivities for untreated and treated animals. Pan-Aspergillus PCR was more sensitive than culture for detection of A. flavus in treated animals (P = 0.002). BAL fluid pan-Aspergillus and species-specific PCRs were comparable in sensitivity to BAL fluid galactomannan (GM) assay. The copy numbers from the qPCR assays correlated with quantitative cultures to determine the pulmonary residual fungal burdens in lung tissue. Pan-Aspergillus and species-specific qPCR assays may improve the rapid and accurate identification of IPA in immunocompromised patients.

Modeling Ecosystem Services for Park Trees: Sensitivity of i-Tree Eco Simulations to Light Exposure and Tree Species Classification

Directory of Open Access Journals (Sweden)

Rocco Pace

2018-02-01

Full Text Available Ecosystem modeling can help decision making regarding planting of urban trees for climate change mitigation and air pollution reduction. Algorithms and models that link the properties of plant functional types, species groups, or single species to their impact on specific ecosystem services have been developed. However, these models require a considerable effort for initialization that is inherently related to uncertainties originating from the high diversity of plant species in urban areas. We therefore suggest a new automated method to be used with the i-Tree Eco model to derive light competition for individual trees and investigate the importance of this property. Since competition depends also on the species, which is difficult to determine from increasingly used remote sensing methodologies, we also investigate the impact of uncertain tree species classification on the ecosystem services by comparing a species-specific inventory determined by field observation with a genus-specific categorization and a model initialization for the dominant deciduous and evergreen species only. Our results show how the simulation of competition affects the determination of carbon sequestration, leaf area, and related ecosystem services and that the proposed method provides a tool for improving estimations. Misclassifications of tree species can lead to large deviations in estimates of ecosystem impacts, particularly concerning biogenic volatile compound emissions. In our test case, monoterpene emissions almost doubled and isoprene emissions decreased to less than 10% when species were estimated to belong only to either two groups instead of being determined by species or genus. It is discussed that this uncertainty of emission estimates propagates further uncertainty in the estimation of potential ozone formation. Overall, we show the importance of using an individual light competition approach and explicitly parameterizing all ecosystem functions at the

Species-specific flight styles of flies are reflected in the response dynamics of a homologue motion sensitive neuron

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Bart eGeurten

2012-03-01

Full Text Available Hoverflies and blowflies have distinctly different flight styles. Yet, both species have been shown to structure their flight behaviour in a way that facilitates extraction of 3D information from the image flow on the retina (optic flow. Neuronal candidates to analyse the optic flow are the tangential cells in the third optical ganglion – the lobula complex. These neurons are directionally selective and integrate the optic flow over large parts of the visual field. Homologue tangential cells in hoverflies and blowflies have a similar morphology. Because blowflies and hoverflies have similar neuronal layout but distinctly different flight behaviours, they are an ideal substrate to pinpoint potential neuronal adaptations to the different flight styles.In this article we describe the relationship between locomotion behaviour and motion vision on three different levels:1.We compare the different flight styles based on the categorisation of flight behaviour into prototypical movements.2.We measure the species specific dynamics of the optic flow under naturalistic flight conditions. We found the translational optic flow of both species to be very different.3.We describe possible adaptations of a homologue motion sensitive neuron. We stimulate this cell in blowflies (Calliphora and hoverflies (Eristalis with naturalistic optic flow generated by both species during free flight. The characterized hoverfly tangential cell responds faster to transient changes in the optic flow than its blowfly homologue. It is discussed whether and how the different dynamical response properties aid optic flow analysis.

Habitat types on the Hanford Site: Wildlife and plant species of concern

Energy Technology Data Exchange (ETDEWEB)

Downs, J.L.; Rickard, W.H.; Brandt, C.A. [and others

1993-12-01

The objective of this report is to provide a comprehensive source of the best available information on Hanford Site sensitive and critical habitats and plants and animals of importance or special status. In this report, sensitive habitats include areas known to be used by threatened, endangered, or sensitive plant or animal species, wetlands, preserves and refuges, and other sensitive habitats outlined in the Hanford Site Baseline Risk Assessment Methodology. Potentially important species for risk assessment and species of special concern with regard to their status as threatened, endangered, or sensitive are described, and potential habitats for these species identified.

Ozone exposure induces the activation of leaf senescence-related processes and morphological and growth changes in seedlings of Mediterranean tree species

International Nuclear Information System (INIS)

Ribas, Angela; Pen-tilde uelas, Josep; Elvira, Susana; Gimeno, Benjamin S.

2005-01-01

Four Mediterranean tree taxa, Quercus ilex subsp. ilex, Quercus ilex subsp. ballota, Olea europaea cv. vulgaris and Ceratonia siliqua, were exposed to different ozone (O 3 ) concentrations in open top chambers (OTCs) during 2 years. Three treatments were applied: charcoal-filtered air (CF), non-filtered air (NF) and non-filtered air plus 40 ppb v of O 3 (NF+). The photochemical maximal efficiency, Fv/Fm, decreased in NF+ plants during the second year of exposure, especially during the most stressful Mediterranean seasons (winter and summer). An increase of δ 13 C was found in three of the four studied species during the first year of exposure. This finding was only maintained in C. siliqua during the second year. Decreases in the chlorophyll content were detected during the first year of fumigations in all the species studied, but not during the second year. The NF+ treatment induced changes in foliar anatomical characteristics, especially in leaf mass per area (LMA) and spongy parenchyma thickness, which increased in some species. A reduction in N content and an increase in δ 15 N were found in all species during the second year when exposed in the NF+ OTCs, suggesting a change in their retranslocation pattern linked to an acceleration of leaf senescence, as also indicated by the above mentioned biochemical and anatomical foliar changes. The two Q. ilex subspecies were the most sensitive species since the changes in N concentration, δ 15 N, chlorophyll, leaf area, LMA and biomass occurred at ambient O 3 concentrations. However, C. siliqua was the most responsive species (29% biomass reduction) when exposed to the NF+ treatment, followed by the two Q. ilex subspecies (14-20%) and O. europaea (no significant reduction). Ozone resistance of the latter species was linked to some plant traits such as chlorophyll concentrations, or spongy parenchyma thickness. - Ozone induces species-specific leaf senescence-related processes and morphological and growth changes in

Ozone exposure induces the activation of leaf senescence-related processes and morphological and growth changes in seedlings of Mediterranean tree species

Energy Technology Data Exchange (ETDEWEB)

Ribas, Angela [CSIC-CEAB-CREAF Ecophysiology Unit, CREAF-Center for Ecological Research and Forestry Applications, Edifici C, Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona (Spain)]. E-mail: a.ribas@creaf.uab.es; Pen-tilde uelas, Josep [CSIC-CEAB-CREAF Ecophysiology Unit, CREAF-Center for Ecological Research and Forestry Applications, Edifici C, Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona (Spain)]. E-mail: josep.penuelas@uab.es; Elvira, Susana [CIEMAT, Avd. Complutense 22, 28040 Madrid (Spain); Gimeno, Benjamin S. [CIEMAT, Avd. Complutense 22, 28040 Madrid (Spain)

2005-03-01

Four Mediterranean tree taxa, Quercus ilex subsp. ilex, Quercus ilex subsp. ballota, Olea europaea cv. vulgaris and Ceratonia siliqua, were exposed to different ozone (O{sub 3}) concentrations in open top chambers (OTCs) during 2 years. Three treatments were applied: charcoal-filtered air (CF), non-filtered air (NF) and non-filtered air plus 40 ppb{sub v} of O{sub 3} (NF+). The photochemical maximal efficiency, Fv/Fm, decreased in NF+ plants during the second year of exposure, especially during the most stressful Mediterranean seasons (winter and summer). An increase of {delta}{sup 13}C was found in three of the four studied species during the first year of exposure. This finding was only maintained in C. siliqua during the second year. Decreases in the chlorophyll content were detected during the first year of fumigations in all the species studied, but not during the second year. The NF+ treatment induced changes in foliar anatomical characteristics, especially in leaf mass per area (LMA) and spongy parenchyma thickness, which increased in some species. A reduction in N content and an increase in {delta}{sup 15}N were found in all species during the second year when exposed in the NF+ OTCs, suggesting a change in their retranslocation pattern linked to an acceleration of leaf senescence, as also indicated by the above mentioned biochemical and anatomical foliar changes. The two Q. ilex subspecies were the most sensitive species since the changes in N concentration, {delta}{sup 15}N, chlorophyll, leaf area, LMA and biomass occurred at ambient O{sub 3} concentrations. However, C. siliqua was the most responsive species (29% biomass reduction) when exposed to the NF+ treatment, followed by the two Q. ilex subspecies (14-20%) and O. europaea (no significant reduction). Ozone resistance of the latter species was linked to some plant traits such as chlorophyll concentrations, or spongy parenchyma thickness. - Ozone induces species-specific leaf senescence-related

Bacillus subtilis Protects Public Goods by Extending Kin Discrimination to Closely Related Species.

Science.gov (United States)

Lyons, Nicholas A; Kolter, Roberto

2017-07-05

Kin discrimination systems are found in numerous communal contexts like multicellularity and are theorized to prevent exploitation of cooperative behaviors. The kin discrimination system in Bacillus subtilis differs from most other such systems because it excludes nonkin cells rather than including kin cells. Because nonkin are the target of the system, B. subtilis can potentially distinguish degrees of nonkin relatedness, not just kin versus nonkin. We examined this by testing a large strain collection of diverse Bacillus species against B. subtilis in different multicellular contexts. The effects of kin discrimination extend to nearby species, as the other subtilis clade species were treated with the same antagonism as nonkin. Species in the less-related pumilus clade started to display varied phenotypes but were mostly still discriminated against, while cereus clade members and beyond were no longer subject to kin discrimination. Seeking a reason why other species are perceived as antagonistic nonkin, we tested the ability of B. subtilis to steal communally produced surfactant from these species. We found that the species treated as nonkin were the only ones that made a surfactant that B. subtilis could utilize and that nonkin antagonism prevented such stealing when the two strains were mixed. The nonkin exclusion kin discrimination method thus allows effective protection of the cooperative behaviors prevalent in multicellularity while still permitting interactions with more distant species that are not a threat. IMPORTANCE Multicellular systems like bacterial biofilms and swarms rely on cooperative behaviors that could be undermined by exploitative invaders. Discriminating kin from nonkin is one way to help guard against such exploitation but has thus far been examined only intraspecifically, so the phylogenetic range of this important trait is unknown. We tested whether Bacillus subtilis treats other species as nonkin by testing a single strain against a

Using genomic DNA-based probe-selection to improve the sensitivity of high-density oligonucleotide arrays when applied to heterologous species

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Townsend Henrik J

2005-11-01

Full Text Available Abstract High-density oligonucleotide (oligo arrays are a powerful tool for transcript profiling. Arrays based on GeneChip® technology are amongst the most widely used, although GeneChip® arrays are currently available for only a small number of plant and animal species. Thus, we have developed a method to improve the sensitivity of high-density oligonucleotide arrays when applied to heterologous species and tested the method by analysing the transcriptome of Brassica oleracea L., a species for which no GeneChip® array is available, using a GeneChip® array designed for Arabidopsis thaliana (L. Heynh. Genomic DNA from B. oleracea was labelled and hybridised to the ATH1-121501 GeneChip® array. Arabidopsis thaliana probe-pairs that hybridised to the B. oleracea genomic DNA on the basis of the perfect-match (PM probe signal were then selected for subsequent B. oleracea transcriptome analysis using a .cel file parser script to generate probe mask files. The transcriptional response of B. oleracea to a mineral nutrient (phosphorus; P stress was quantified using probe mask files generated for a wide range of gDNA hybridisation intensity thresholds. An example probe mask file generated with a gDNA hybridisation intensity threshold of 400 removed > 68 % of the available PM probes from the analysis but retained >96 % of available A. thaliana probe-sets. Ninety-nine of these genes were then identified as significantly regulated under P stress in B. oleracea, including the homologues of P stress responsive genes in A. thaliana. Increasing the gDNA hybridisation intensity thresholds up to 500 for probe-selection increased the sensitivity of the GeneChip® array to detect regulation of gene expression in B. oleracea under P stress by up to 13-fold. Our open-source software to create probe mask files is freely available http://affymetrix.arabidopsis.info/xspecies/ and may be used to facilitate transcriptomic analyses of a wide range of plant and animal

Bleaching response of coral species in the context of assemblage response

Science.gov (United States)

Swain, Timothy D.; DuBois, Emily; Goldberg, Scott J.; Backman, Vadim; Marcelino, Luisa A.

2017-06-01

Caribbean coral reefs are declining due to a mosaic of local and global stresses, including climate change-induced thermal stress. Species and assemblage responses differ due to factors that are not easily identifiable or quantifiable. We calculated a novel species-specific metric of coral bleaching response, taxon- α and - β, which relates the response of a species to that of its assemblages for 16 species over 18 assemblages. By contextualizing species responses within the response of their assemblages, the effects of environmental factors are removed and intrinsic differences among taxa are revealed. Most corals experience either a saturation response, overly sensitive to weak stress ( α > 0) but under-responsive compared to assemblage bleaching ( β bleaching ( β > 1). This metric may help reveal key factors of bleaching susceptibility and identify species as targets for conservation.

Drought resilience across ecologically dominant species: An experiment-model integration approach

Science.gov (United States)

Felton, A. J.; Warren, J.; Ricciuto, D. M.; Smith, M. D.

2017-12-01

Poorly understood are the mechanisms contributing to variability in ecosystem recovery following drought. Grasslands of the central U.S. are ecologically and economically important ecosystems, yet are also highly sensitive to drought. Although characteristics of these ecosystems change across gradients of temperature and precipitation, a consistent feature among these systems is the presence of highly abundant, dominant grass species that control biomass production. As a result, the incorporation of these species' traits into terrestrial biosphere models may constrain predictions amid increases in climatic variability. Here we report the results of a modeling-experiment (MODEX) research approach. We investigated the physiological, morphological and growth responses of the dominant grass species from each of the four major grasslands of the central U.S. (ranging from tallgrass prairie to desert grassland) following severe drought. Despite significant differences in baseline values, full recovery in leaf physiological function was evident across species, of which was consistently driven by the production of new leaves. Further, recovery in whole-plant carbon uptake tended to be driven by shifts in allocation from belowground to aboveground structures. However, there was clear variability among species in the magnitude of this dynamic as well as the relative allocation to stem versus leaf production. As a result, all species harbored the physiological capacity to recover from drought, yet we posit that variability in the recovery of whole-plant carbon uptake to be more strongly driven by variability in the sensitivity of species' morphology to soil moisture increases. The next step of this project will be to incorporate these and other existing data on these species and ecosystems into the community land model in an effort to test the sensitivity of this model to these data.

prevalence of biting and non-biting flies in relation to species

African Journals Online (AJOL)

USER

support high abundance of biting flies due to the favourable conditions within the forest for breeding, refuge and easy migration of adult females to animal cages to seek for blood meal. Table 1: Abundance of Biting Flies in Relation to Species in the Jos Museum. Zoological Garden. Site. Stomoxys calcitrans. Haematopota.

Global assessment of the effects of terrestrial acidification on plant species richness

International Nuclear Information System (INIS)

Azevedo, Ligia B.; Zelm, Rosalie van; Hendriks, A. Jan; Bobbink, Roland; Huijbregts, Mark A.J.

2013-01-01

This study estimates the potential losses of vascular plant species richness due to terrestrial acidification for different world's biomes. We used empirical occurrence data of 2409 species from 140 studies and estimated the relative species richness – pH response curves using logistic regressions. The regressions were then used to quantify the fraction of species that are potentially lost due to soil pH changes. Although we found considerable variability within biomes, out results show that the pH at which species richness was maximized was found to be the lowest in (sub)tropical forests (pH = 4.1) and the highest in deserts (pH = 7.4). We also found that (sub)tropical moist forests are highly sensitive to decreases of in soil pH below 4.1. This study can be coupled with existing atmospheric deposition models to quantify the risk of species richness loss following soil acidification. Highlights: ► We compare the sensitivity of four biomes to soil acidification. ► We develop logistic regressions using observational field data. ► Sub(tropical) moist forests are highly affected by pH decreases. ► Logistic regressions can be linked to global scale atmospheric and soil fate models. -- Relationships of potential species richness loss along a soil pH gradient are proposed

Balancing data sharing requirements for analyses with data sensitivity

Science.gov (United States)

Jarnevich, C.S.; Graham, J.J.; Newman, G.J.; Crall, A.W.; Stohlgren, T.J.

2007-01-01

Data sensitivity can pose a formidable barrier to data sharing. Knowledge of species current distributions from data sharing is critical for the creation of watch lists and an early warning/rapid response system and for model generation for the spread of invasive species. We have created an on-line system to synthesize disparate datasets of non-native species locations that includes a mechanism to account for data sensitivity. Data contributors are able to mark their data as sensitive. This data is then 'fuzzed' in mapping applications and downloaded files to quarter-quadrangle grid cells, but the actual locations are available for analyses. We propose that this system overcomes the hurdles to data sharing posed by sensitive data. ?? 2006 Springer Science+Business Media B.V.

Diagnostic sensitivity of ultrasound, radiography and computed tomography for gender determination in four species of lizards.

Science.gov (United States)

Di Ianni, Francesco; Volta, Antonella; Pelizzone, Igor; Manfredi, Sabrina; Gnudi, Giacomo; Parmigiani, Enrico

2015-01-01

Gender determination is frequently requested by reptile breeders, especially for species with poor or absent sexual dimorphism. The aims of the current study were to describe techniques and diagnostic sensitivities of ultrasound, radiography, and computed tomography for gender determination (identification of hemipenes) in four species of lizards. Nineteen lizards of known sex, belonging to four different species (Pogona vitticeps, Uromastyx aegyptia, Tiliqua scincoides, Gerrhosaurus major) were prospectively enrolled. With informed owner consent, ultrasound, noncontrast CT, contrast radiography, and contrast CT (with contrast medium administered into the cloaca) were performed in conscious animals. Imaging studies were reviewed by three different operators, each unaware of the gender of the animals and of the results of the other techniques. The lizard was classified as a male when hemipenes were identified. Nineteen lizards were included in the study, 10 females and nine males. The hemipenes were seen on ultrasound in only two male lizards, and appeared as oval hypoechoic structures. Radiographically, hemipenes filled with contrast medium appeared as spindle-shaped opacities. Noncontrast CT identified hemipenes in only two lizards, and these appeared as spindle-shaped kinked structures with hyperattenuating content consistent with smegma. Hemipenes were correctly identified in all nine males using contrast CT (accuracy of 100%). Accuracy of contrast radiography was excellent (94.7%). Accuracy of ultrasound and of noncontrast CT was poor (64.3% and 63.1%, respectively). Findings from the current study supported the use of contrast CT or contrast radiography for gender determination in lizards. © 2014 American College of Veterinary Radiology.

Diagnosis of gluten related disorders: Celiac disease, wheat allergy and non-celiac gluten sensitivity

Science.gov (United States)

Elli, Luca; Branchi, Federica; Tomba, Carolina; Villalta, Danilo; Norsa, Lorenzo; Ferretti, Francesca; Roncoroni, Leda; Bardella, Maria Teresa

2015-01-01

Cereal crops and cereal consumption have had a vital role in Mankind’s history. In the recent years gluten ingestion has been linked with a range of clinical disorders. Gluten-related disorders have gradually emerged as an epidemiologically relevant phenomenon with an estimated global prevalence around 5%. Celiac disease, wheat allergy and non-celiac gluten sensitivity represent different gluten-related disorders. Similar clinical manifestations can be observed in these disorders, yet there are peculiar pathogenetic pathways involved in their development. Celiac disease and wheat allergy have been extensively studied, while non-celiac gluten sensitivity is a relatively novel clinical entity, believed to be closely related to other gastrointestinal functional syndromes. The diagnosis of celiac disease and wheat allergy is based on a combination of findings from the patient’s clinical history and specific tests, including serology and duodenal biopsies in case of celiac disease, or laboratory and functional assays for wheat allergy. On the other hand, non-celiac gluten sensitivity is still mainly a diagnosis of exclusion, in the absence of clear-cut diagnostic criteria. A multimodal pragmatic approach combining findings from the clinical history, symptoms, serological and histological tests is required in order to reach an accurate diagnosis. A thorough knowledge of the differences and overlap in clinical presentation among gluten-related disorders, and between them and other gastrointestinal disorders, will help clinicians in the process of differential diagnosis. PMID:26109797

Reactive oxygen species dynamics in roots of salt sensitive and salt tolerant cultivars of rice.

Science.gov (United States)

Saini, Shivani; Kaur, Navdeep; Pati, Pratap Kumar

2018-06-01

Salinity stress is one of the major constraints for growth and survival of plants that affects rice productivity worldwide. Hence, in the present study, roots of two contrasting salinity sensitive cultivars, IR64 (IR64, salt sensitive) and Luna Suvarna (LS, salt tolerant) were compared with regard to the levels of reactive oxygen species (ROS) to derive clues for their differential salt stress adaptation mechanisms. In our investigation, the tolerant cultivar exhibited longer primary roots, more lateral roots, higher root number leading to increased root biomass, with respect to IR64. It was observed that LS roots maintained higher level of H 2 O 2 in comparison to IR64. The activities of various enzymes involved in enzymatic antioxidant defense mechanism (SOD, CAT, GPX, DHAR and MDHAR) were found to be greater in LS roots. Further, the higher transcript level accumulation of genes encoding ROS generating (RbohA, RbohD and RbohE) and scavenging enzymes (Fe-SOD, Chloroplastic Cu/Zn-SOD, CAT and DHAR) were noticed in the roots of tolerant cultivar, LS. Moreover, the content of other stress markers such as total protein and proline were also elevated in LS roots. While, the expression of proline biosynthesis gene (P5CS) and proline catabolism gene (PDH) was observed to be lower in LS. Copyright © 2018. Published by Elsevier Inc.

Relationship between ecomorphology and trophic segregation in four closely related sympatric fish species (Teleostei, Sciaenidae).

Science.gov (United States)

Blasina, Gabriela; Molina, Juan; Lopez Cazorla, Andrea; Díaz de Astarloa, Juan

This study explores the relationship between ecomorphology and trophic segregation in four closely related sympatric fish species (Teleostei, Sciaenidae) that are known to differ in their trophic habits. Only adult specimens were analyzed: 103 Cynoscion guatucupa, 77 Pogonias cromis, 61 Micropogonias furnieri, and 48 Menticirrhus americanus. The four species presented divergent ecomorphological traits related to swimming agility, prey spotting and capture, and the potential size of prey they were able to swallow. Results suggest that these sciaenid species can partition the food resources, even though they completely overlap in space. Differences in their ecomorphological traits appear to correlate closely with the diet and consequently could explain the trophic differentiation observed. Arguably, these ecomorphological differences play a significant role in the coexistence of the adults of these sympatric fish species. Copyright © 2016 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Species from within the Phytophthora cryptogea complex and related species, P. erythroseptica and P. sansomeana, readily hybridize.

Science.gov (United States)

Safaiefarahani, Banafsheh; Mostowfizadeh-Ghalamfarsa, Reza; Hardy, Giles E St J; Burgess, Treena I

2016-08-01

During a study on the phylogenetic relationships between species in the Phytophthora cryptogea complex and related species, Phytophthora erythroseptica and Phytophthora sansomeana, 19 hybrid isolates with multiple polymorphisms in the nuclear sequences were observed. Molecular characterization of hybrids was achieved by sequencing three nuclear (internal transcribed spacers, β-tubulin (TUB), heat shock protein 90) and two mitochondrial (cytochrome c oxidase subunit I (coxI), NADH dehydrogenase subunit I (NADH)) gene regions and cloning of the single-copy nuclear gene, TUB. Based on the molecular studies the hybrid isolates belonged to six distinct groups between P. cryptogea, P. erythroseptica, Phytophthora pseudocryptogea, P. sansomeana, and Phytophthora sp. kelmania. In all cases, only a single coxI and NADH allele was detected and nuclear genes were biparentally inherited, suggesting that the hybrids arose from sexual recombination events. Colony morphology, growth rate, cardinal temperatures, breeding system, and morphology of sporangia, oogonia, oospores, and antheridia were also determined. Some morphological differences between the hybrids and the parental species were noted; however, they were not sufficient to reliably distinguish the taxa and DNA markers from nuclear and mitochondrial genes will to be necessary for their identification. The parental species are all important pathogens of agricultural fields that have been transported globally. With the apparent ease of hybridization within this group there is ample opportunity for virulent hybrids to form, perhaps with extended host ranges. Copyright © 2016 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Predicting relative species composition within mixed conifer forest pixels using zero‐inflated models and Landsat imagery

Science.gov (United States)

Shannon L. Savage; Rick L. Lawrence; John R. Squires

2015-01-01

Ecological and land management applications would often benefit from maps of relative canopy cover of each species present within a pixel, instead of traditional remote-sensing based maps of either dominant species or percent canopy cover without regard to species composition. Widely used statistical models for remote sensing, such as randomForest (RF),...

Effects of acute NH3 air pollution on N-sensitive and N-tolerant lichen species.

Science.gov (United States)

Paoli, Luca; Maslaňáková, Ivana; Grassi, Alice; Bačkor, Martin; Loppi, Stefano

2015-12-01

Lichens are sensitive to the presence of ammonia (NH3) in the environment. However, in order to use them as reliable indicators in biomonitoring studies, it is necessary to establish unequivocally the occurrence of certain symptoms following the exposure to NH3 in the environment. In this paper, we simulated an episode of acute air pollution due to the release of NH3. The biological effects of acute air pollution by atmospheric NH3 have been investigated using N-sensitive (Flavoparmelia caperata) and N-tolerant (Xanthoria parietina) species. Lichen samples were exposed to ecologically relevant NH3 concentrations for 8 weeks, simulating three areas of impact: a control area (2 μg/m(3)), an area of intermediate impact (2-35 μg/m(3)) and an area of high impact (10-315 μg/m(3)), with a peak of pollution reached between the fourth and fifth week. Ammonia affected both the photobiont and the mycobiont in F. caperata, while in X. parietina only the photosynthetic performance of the photobiont was altered after exposure to the highest concentration. In the photobiont of F. caperata we recorded chlorophyll degradation as indicated by OD435/415 ratio, decrease of the photosynthetic performance (as reflected by the maximum quantum yield of primary photochemistry FV/FM and the performance index PIABS); in the mycobiont, ergosterol reduction, membrane lipid peroxidation (as reflected by the increase of thiobarbituric acid reactive substances), alteration (decrease) of the secondary metabolite usnic acid. No effects were detected on caperatic acid and dehydrogenase activity. In X. parietina, the only signal determined by NH3 was the alteration of FV/FM and the performance index PIABS. The results suggest that physiological parameters in N-sensitive lichens well reflect the effects of NH3 exposure and can be applied as early indicators in monitoring studies. Copyright © 2015 Elsevier Inc. All rights reserved.

[Phylogenetic analysis of closely related Leuconostoc citreum species based on partial housekeeping genes].

Science.gov (United States)

Lv, Qiang; Chen, Ming; Xu, Haiyan; Song, Yuqin; Sun, Zhihong; Dan, Tong; Sun, Tiansong

2013-07-04

Using the 16S rRNA, dnaA, murC and pyrG gene sequences, we identified the phylogenetic relationship among closely related Leuconostoc citreum species. Seven Leu. citreum strains originally isolated from sourdough were characterized by PCR methods to amplify the dnaA, murC and pyrG gene sequences, which were determined to assess the suitability as phylogenetic markers. Then, we estimated the genetic distance and constructed the phylogenetic trees including 16S rRNA and above mentioned three housekeeping genes combining with published corresponding sequences. By comparing the phylogenetic trees, the topology of three housekeeping genes trees were consistent with that of 16S rRNA gene. The homology of closely related Leu. citreum species among dnaA, murC, pyrG and 16S rRNA gene sequences were different, ranged from75.5% to 97.2%, 50.2% to 99.7%, 65.0% to 99.8% and 98.5% 100%, respectively. The phylogenetic relationship of three housekeeping genes sequences were highly consistent with the results of 16S rRNA gene sequence, while the genetic distance of these housekeeping genes were extremely high than 16S rRNA gene. Consequently, the dnaA, murC and pyrG gene are suitable for classification and identification closely related Leu. citreum species.

Chloroplast and mitochondrial microsatellites for Millettia pinnata (Fabaceae) and cross-amplification in related species1

Science.gov (United States)

Wang, Yanling; Xie, Hongxian; Yang, Yi; Huang, Yelin; Wang, Jianwu; Tan, Fengxiao

2017-01-01

Premise of the study: Chloroplast and mitochondrial microsatellites were identified to study the population genetics of Millettia pinnata (Fabaceae). Methods and Results: Based on publicly available plastid genome sequence data of M. pinnata, 42 primer pairs were developed, of which 17 displayed polymorphisms across 89 individuals from four populations. For chloroplast loci, two to six alleles were recovered and the unbiased haploid diversity per locus ranged from 0.391 to 0.857. For mitochondrial loci, two to four alleles were recovered and the unbiased haploid diversity ranged from 0.264 to 0.740. Sixteen of the 17 screened markers could be successfully amplified in the related species M. pulchra. Conclusions: The 17 microsatellite markers developed here exhibited variation in M. pinnata and 16 presented transferability in the related species M. pulchra, suggesting that these markers will be valuable for genetic studies across M. pinnata and its related species. PMID:28529836

M-GCAT: interactively and efficiently constructing large-scale multiple genome comparison frameworks in closely related species

Directory of Open Access Journals (Sweden)

Messeguer Xavier

2006-10-01

Full Text Available Abstract Background Due to recent advances in whole genome shotgun sequencing and assembly technologies, the financial cost of decoding an organism's DNA has been drastically reduced, resulting in a recent explosion of genomic sequencing projects. This increase in related genomic data will allow for in depth studies of evolution in closely related species through multiple whole genome comparisons. Results To facilitate such comparisons, we present an interactive multiple genome comparison and alignment tool, M-GCAT, that can efficiently construct multiple genome comparison frameworks in closely related species. M-GCAT is able to compare and identify highly conserved regions in up to 20 closely related bacterial species in minutes on a standard computer, and as many as 90 (containing 75 cloned genomes from a set of 15 published enterobacterial genomes in an hour. M-GCAT also incorporates a novel comparative genomics data visualization interface allowing the user to globally and locally examine and inspect the conserved regions and gene annotations. Conclusion M-GCAT is an interactive comparative genomics tool well suited for quickly generating multiple genome comparisons frameworks and alignments among closely related species. M-GCAT is freely available for download for academic and non-commercial use at: http://alggen.lsi.upc.es/recerca/align/mgcat/intro-mgcat.html.

Validation of microsatellite multiplexes for parentage analysis and species discrimination in two hybridizing species of coral reef fish (Plectropomus spp., Serranidae)

KAUST Repository

Harrison, H.B.

2014-04-24

Microsatellites are often considered ideal markers to investigate ecological processes in animal populations. They are regularly used as genetic barcodes to identify species, individuals, and infer familial relationships. However, such applications are highly sensitive the number and diversity of microsatellite markers, which are also prone to error. Here, we propose a novel framework to assess the suitability of microsatellite datasets for parentage analysis and species discrimination in two closely related species of coral reef fish, Plectropomus leopardus and P. maculatus (Serranidae). Coral trout are important fisheries species throughout the Indo-Pacific region and have been shown to hybridize in parts of the Great Barrier Reef, Australia. We first describe the development of 25 microsatellite loci and their integration to three multiplex PCRs that co-amplify in both species. Using simulations, we demonstrate that the complete suite of markers provides appropriate power to discriminate between species, detect hybrid individuals, and resolve parent-offspring relationships in natural populations, with over 99.6% accuracy in parent-offspring assignments. The markers were also tested on seven additional species within the Plectropomus genus with polymorphism in 28-96% of loci. The multiplex PCRs developed here provide a reliable and cost-effective strategy to investigate evolutionary and ecological dynamics and will be broadly applicable in studies of wild populations and aquaculture brood stocks for these closely related fish species. 2014 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.

Validation of microsatellite multiplexes for parentage analysis and species discrimination in two hybridizing species of coral reef fish (Plectropomus spp., Serranidae)

KAUST Repository

Harrison, H.B.; Feldheim, K.A.; Jones, G.P.; Ma, K.; Mansour, H.; Perumal, S.; Williamson, D.H.; Berumen, Michael L.

2014-01-01

Microsatellites are often considered ideal markers to investigate ecological processes in animal populations. They are regularly used as genetic barcodes to identify species, individuals, and infer familial relationships. However, such applications are highly sensitive the number and diversity of microsatellite markers, which are also prone to error. Here, we propose a novel framework to assess the suitability of microsatellite datasets for parentage analysis and species discrimination in two closely related species of coral reef fish, Plectropomus leopardus and P. maculatus (Serranidae). Coral trout are important fisheries species throughout the Indo-Pacific region and have been shown to hybridize in parts of the Great Barrier Reef, Australia. We first describe the development of 25 microsatellite loci and their integration to three multiplex PCRs that co-amplify in both species. Using simulations, we demonstrate that the complete suite of markers provides appropriate power to discriminate between species, detect hybrid individuals, and resolve parent-offspring relationships in natural populations, with over 99.6% accuracy in parent-offspring assignments. The markers were also tested on seven additional species within the Plectropomus genus with polymorphism in 28-96% of loci. The multiplex PCRs developed here provide a reliable and cost-effective strategy to investigate evolutionary and ecological dynamics and will be broadly applicable in studies of wild populations and aquaculture brood stocks for these closely related fish species. 2014 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.

Number of endemic and native plant species in the Galapagos Archipelago in relation to geographical parameters

DEFF Research Database (Denmark)

Willerslev, Eske; Hansen, Anders J.; Nielsen, Kirstine Klitgaard

2002-01-01

By simple and multiple regression analyses we investigate updated species numbers of endemic and native vascular plants and seed plants in the Galapagos Archipelago in relation to geographical parameters. We find that the best models to describe species numbers are regression models with log......-transformed species numbers as dependent and log-transformed modified area (i.e. area not covered with barren lava) as an independent variable. This holds both for total species number, for native species number, for endemic species number and for total number of seed plants as well as number of endemic seed plants...

Cross-fostering reveals seasonal changes in the relative fitness of two competing species of flycatchers

NARCIS (Netherlands)

Qvarnstrom, A; Svedin, N; Wiley, C; Veen, T; Gustafsson, L

Spatial and temporal heterogeneity in relative fitness of competing species is a key factor affecting the structure of communities. However, it is not intuitive whys species that are ecologically similar should differ in their response to environmental changes. Here we show that two sympatric

Insulin sensitivity in relation to fat distribution and plasma adipocytokines among abusers of anabolic androgenic steroids

DEFF Research Database (Denmark)

Rasmussen, Jon Jarløv; Schou, Morten; Selmer, Christian

2017-01-01

Objective: Abuse of anabolic androgenic steroids (AAS) is prevalent among young men, but information regarding effects on insulin sensitivity and fat distribution is limited. The objective was to investigate insulin sensitivity in relation to fat distribution and adipocytokines among current...

Phylogenetic reconstruction and DNA barcoding for closely related pine moth species (Dendrolimus) in China with multiple gene markers.

Science.gov (United States)

Dai, Qing-Yan; Gao, Qiang; Wu, Chun-Sheng; Chesters, Douglas; Zhu, Chao-Dong; Zhang, Ai-Bing

2012-01-01

Unlike distinct species, closely related species offer a great challenge for phylogeny reconstruction and species identification with DNA barcoding due to their often overlapping genetic variation. We tested a sibling species group of pine moth pests in China with a standard cytochrome c oxidase subunit I (COI) gene and two alternative internal transcribed spacer (ITS) genes (ITS1 and ITS2). Five different phylogenetic/DNA barcoding analysis methods (Maximum likelihood (ML)/Neighbor-joining (NJ), "best close match" (BCM), Minimum distance (MD), and BP-based method (BP)), representing commonly used methodology (tree-based and non-tree based) in the field, were applied to both single-gene and multiple-gene analyses. Our results demonstrated clear reciprocal species monophyly for three relatively distant related species, Dendrolimus superans, D. houi, D. kikuchii, as recovered by both single and multiple genes while the phylogenetic relationship of three closely related species, D. punctatus, D. tabulaeformis, D. spectabilis, could not be resolved with the traditional tree-building methods. Additionally, we find the standard COI barcode outperforms two nuclear ITS genes, whatever the methods used. On average, the COI barcode achieved a success rate of 94.10-97.40%, while ITS1 and ITS2 obtained a success rate of 64.70-81.60%, indicating ITS genes are less suitable for species identification in this case. We propose the use of an overall success rate of species identification that takes both sequencing success and assignation success into account, since species identification success rates with multiple-gene barcoding system were generally overestimated, especially by tree-based methods, where only successfully sequenced DNA sequences were used to construct a phylogenetic tree. Non-tree based methods, such as MD, BCM, and BP approaches, presented advantages over tree-based methods by reporting the overall success rates with statistical significance. In addition, our

Phylogenetic reconstruction and DNA barcoding for closely related pine moth species (Dendrolimus in China with multiple gene markers.

Directory of Open Access Journals (Sweden)

Qing-Yan Dai

Full Text Available Unlike distinct species, closely related species offer a great challenge for phylogeny reconstruction and species identification with DNA barcoding due to their often overlapping genetic variation. We tested a sibling species group of pine moth pests in China with a standard cytochrome c oxidase subunit I (COI gene and two alternative internal transcribed spacer (ITS genes (ITS1 and ITS2. Five different phylogenetic/DNA barcoding analysis methods (Maximum likelihood (ML/Neighbor-joining (NJ, "best close match" (BCM, Minimum distance (MD, and BP-based method (BP, representing commonly used methodology (tree-based and non-tree based in the field, were applied to both single-gene and multiple-gene analyses. Our results demonstrated clear reciprocal species monophyly for three relatively distant related species, Dendrolimus superans, D. houi, D. kikuchii, as recovered by both single and multiple genes while the phylogenetic relationship of three closely related species, D. punctatus, D. tabulaeformis, D. spectabilis, could not be resolved with the traditional tree-building methods. Additionally, we find the standard COI barcode outperforms two nuclear ITS genes, whatever the methods used. On average, the COI barcode achieved a success rate of 94.10-97.40%, while ITS1 and ITS2 obtained a success rate of 64.70-81.60%, indicating ITS genes are less suitable for species identification in this case. We propose the use of an overall success rate of species identification that takes both sequencing success and assignation success into account, since species identification success rates with multiple-gene barcoding system were generally overestimated, especially by tree-based methods, where only successfully sequenced DNA sequences were used to construct a phylogenetic tree. Non-tree based methods, such as MD, BCM, and BP approaches, presented advantages over tree-based methods by reporting the overall success rates with statistical significance. In

1 Species Diversity and Relative Abundance.cdr

African Journals Online (AJOL)

Administrator

from beach seine landings along the central coast during the study period. Landing sites were Winneba, Saltpond and Cape Coast. (Fig. 1). Fish identification was done in the laboratory using manuals (Schneider, 1990;. Kwei & Ofori-Adu, 2005). The identifications were to the family and species levels. Various fish species ...

Development of oligonucleotide microarrays for simultaneous multi-species identification of Phellinus tree-pathogenic fungi.

Science.gov (United States)

Tzean, Yuh; Shu, Po-Yao; Liou, Ruey-Fen; Tzean, Shean-Shong

2016-03-01

Polyporoid Phellinus fungi are ubiquitously present in the environment and play an important role in shaping forest ecology. Several species of Phellinus are notorious pathogens that can affect a broad variety of tree species in forest, plantation, orchard and urban habitats; however, current detection methods are overly complex and lack the sensitivity required to identify these pathogens at the species level in a timely fashion for effective infestation control. Here, we describe eight oligonucleotide microarray platforms for the simultaneous and specific detection of 17 important Phellinus species, using probes generated from the internal transcribed spacer regions unique to each species. The sensitivity, robustness and efficiency of this Phellinus microarray system was subsequently confirmed against template DNA from two key Phellinus species, as well as field samples collected from tree roots, trunks and surrounding soil. This system can provide early, specific and convenient detection of Phellinus species for forestry, arboriculture and quarantine inspection, and could potentially help to mitigate the environmental and economic impact of Phellinus-related diseases. © 2015 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Non-coding changes cause sex-specific wing size differences between closely related species of Nasonia

NARCIS (Netherlands)

Loehlin, David W.; Oliveira, Deodoro C. S. G.; Edwards, Rachel; Giebel, Jonathan D.; Clark, Michael E.; Cattani, M. Victoria; van de Zande, Louis; Verhulst, Eveline C.; Beukeboom, Leo W.; Munoz-Torres, Monica; Werren, John H.

The genetic basis of morphological differences among species is still poorly understood. We investigated the genetic basis of sex-specific differences in wing size between two closely related species of Nasonia by positional cloning a major male-specific locus, wing-size1 (ws1). Male wing size

Long-Term Changes in Species Composition and Relative Abundances of Sharks at a Provisioning Site

OpenAIRE

Brunnschweiler, Juerg M.; Abrantes, Kátya G.; Barnett, Adam

2014-01-01

Diving with sharks, often in combination with food baiting/provisioning, has become an important product of today's recreational dive industry. Whereas the effects baiting/provisioning has on the behaviour and abundance of individual shark species are starting to become known, there is an almost complete lack of equivalent data from multi-species shark diving sites. In this study, changes in species composition and relative abundances were determined at the Shark Reef Marine Reserve, a multi-...

Summary of the especies of Spanish vegetation sensitive to different pollutants

International Nuclear Information System (INIS)

Varela Gonzales, J.; Sanchez Cabrero, B.; Sanchez Gimeno, B.

1987-01-01

A detail literature review of the sensitivity of the species of Spanish vegetation to various pollutants was made. An impact scale was created to describe the qualitative degree of sensitivity to which each specie is affected by major atmospheric pollutants: very sensitive, sensitive, intermediate sensitive and resistent. This type of study, combined with studies of emission, concentration and dispersion of air pollution, is of great interest to evaluate the environmental impact to the vegetation community. (author) 45 refs

Terricolous alpine lichens are sensitive to both load and concentration of applied nitrogen and have potential as bioindicators of nitrogen deposition

International Nuclear Information System (INIS)

Britton, Andrea J.; Fisher, Julia M.

2010-01-01

The influence of applied nitrogen (N) concentration and load on thallus chemistry and growth of five terricolous alpine lichen species was investigated in a three-month N addition study. Thallus N content was influenced by both concentration and load; but the relative importance of these parameters varied between species. Growth was most affected by concentration. Thresholds for effects observed in this study support a low critical load for terricolous lichen communities ( -1 y -1 ) and suggest that concentrations of N currently encountered in UK cloudwater may have detrimental effects on the growth of sensitive species. The significance of N concentration effects on sensitive species also highlights the need to avoid artificially high concentrations when designing N addition experiments. Given the sensitivity of some species to extremely low loads and concentrations of N we suggest that terricolous lichens have potential as indicators of deposition and impact in northern and alpine ecosystems. - Terricolous lichen species' N content responds to both applied N concentration and load while applied N concentration has greatest effects on growth.

Terricolous alpine lichens are sensitive to both load and concentration of applied nitrogen and have potential as bioindicators of nitrogen deposition

Energy Technology Data Exchange (ETDEWEB)

Britton, Andrea J., E-mail: a.britton@macaulay.ac.u [Macaulay Land Use Research Institute, Craigiebuckler, Aberdeen AB15 8QH (United Kingdom); Fisher, Julia M. [Macaulay Land Use Research Institute, Craigiebuckler, Aberdeen AB15 8QH (United Kingdom)

2010-05-15

The influence of applied nitrogen (N) concentration and load on thallus chemistry and growth of five terricolous alpine lichen species was investigated in a three-month N addition study. Thallus N content was influenced by both concentration and load; but the relative importance of these parameters varied between species. Growth was most affected by concentration. Thresholds for effects observed in this study support a low critical load for terricolous lichen communities (<7.5 kg N ha{sup -1} y{sup -1}) and suggest that concentrations of N currently encountered in UK cloudwater may have detrimental effects on the growth of sensitive species. The significance of N concentration effects on sensitive species also highlights the need to avoid artificially high concentrations when designing N addition experiments. Given the sensitivity of some species to extremely low loads and concentrations of N we suggest that terricolous lichens have potential as indicators of deposition and impact in northern and alpine ecosystems. - Terricolous lichen species' N content responds to both applied N concentration and load while applied N concentration has greatest effects on growth.

Remote Sensing of Seagrass Leaf Area Index and Species: The Capability of a Model Inversion Method Assessed by Sensitivity Analysis and Hyperspectral Data of Florida Bay

Directory of Open Access Journals (Sweden)

John D. Hedley

2017-11-01

Full Text Available The capability for mapping two species of seagrass, Thalassia testudinium and Syringodium filiforme, by remote sensing using a physics based model inversion method was investigated. The model was based on a three-dimensional canopy model combined with a model for the overlying water column. The model included uncertainty propagation based on variation in leaf reflectances, canopy structure, water column properties, and the air-water interface. The uncertainty propagation enabled both a-priori predictive sensitivity analysis of potential capability and the generation of per-pixel error bars when applied to imagery. A primary aim of the work was to compare the sensitivity analysis to results achieved in a practical application using airborne hyperspectral data, to gain insight on the validity of sensitivity analyses in general. Results showed that while the sensitivity analysis predicted a weak but positive discrimination capability for species, in a practical application the relevant spectral differences were extremely small compared to discrepancies in the radiometric alignment of the model with the imagery—even though this alignment was very good. Complex interactions between spectral matching and uncertainty propagation also introduced biases. Ability to discriminate LAI was good, and comparable to previously published methods using different approaches. The main limitation in this respect was spatial alignment with the imagery with in situ data, which was heterogeneous on scales of a few meters. The results provide insight on the limitations of physics based inversion methods and seagrass mapping in general. Complex models can degrade unpredictably when radiometric alignment of the model and imagery is not perfect and incorporating uncertainties can have non-intuitive impacts on method performance. Sensitivity analyses are upper bounds to practical capability, incorporating a term for potential systematic errors in radiometric alignment may

Ozone air pollution effects on tree-ring growth,{delta}{sup 13}C, visible foliar injury and leaf gas exchange in three ozone-sensitive woody plant species

Energy Technology Data Exchange (ETDEWEB)

Novak, K. [Swiss Federal Inst. for Forest, Snow and Landscape Research, Birmensdorf (Switzerland); Agroscope FAL Reckenholz, Swiss Federal Research Station for Agroecology and Agriculture, Zurich (Switzerland); Saurer, M. [Paul Scherrer Inst. Villigen (Switzerland); Fuhrer, J. [Agroscope FAL Reckenholz, Swiss Federal Research Station for Agroecology and Agriculture, Zurich (Switzerland); Skelly, J.M. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Plant Pathology; Krauchi, N.; Schaub, M. [Swiss Federal Inst. for Forest, Snow and Landscape Research, Birmensdorf (Switzerland)

2007-07-15

Species specific plant responses to tropospheric ozone pollution depend on a range of morphological, biochemical and physiological characteristics as well as environmental factors. The effects of ambient tropospheric ozone on annual tree-ring growth, {delta}{sup 13} C in the rings, leaf gas exchange and ozone-induced visible foliar injury in three ozone-sensitive woody plant species in southern Switzerland were assessed during the 2001 and 2002 growing seasons. Seedlings of Populus nigra L., Viburnum lantana L. and Fraxinus excelsior L. were exposed to charcoal-filtered air and non-filtered air in open-top chambers, and to ambient air (AA) in open plots. The objective was to determine if a relationship exists between measurable ozone-induced effects at the leaf level and subsequent changes in annual tree-ring growth and {delta} {sup 13} C signatures. The visible foliar injury, early leaf senescence and premature leaf loss in all species was attributed to the ambient ozone exposures in the region. Ozone had pronounced negative effects on net photosynthesis and stomatal conductance in all species in 2002 and in V. lantana and F. excelsior in 2001. Water-use efficiency decreased and intercellular carbon dioxide concentrations increased in all species in response to ozone in 2002 only. The width and {delta}{sup 13} C of the 2001 and 2002 growth rings were measured for all species at the end of the 2002 growing season. Significant ozone-induced effects at the leaf level did not correspond to reduced tree-ring growth or increased {delta}{sup 13} C in all species, suggesting that the timing of ozone exposure and extent of leaf-level responses may be relevant in determining the sensitivity of tree productivity to ozone exposure. 48 refs., 4 tabs., 2 figs.

Citizen science identifies the effects of nitrogen deposition, climate and tree species on epiphytic lichens across the UK.

Science.gov (United States)

Welden, N A; Wolseley, P A; Ashmore, M R

2018-01-01

A national citizen survey quantified the abundance of epiphytic lichens that are known to be either sensitive or tolerant to nitrogen (N) deposition. Records were collected across the UK from over 10,000 individual trees of 22 deciduous species. Mean abundance of tolerant and sensitive lichens was related to mean N deposition rates and climatic variables at a 5 km scale, and the response of lichens was compared on the three most common trees (Quercus, Fraxinus and Acer) and by assigning all 22 tree species to three bark pH groups. The abundance of N-sensitive lichens on trunks decreased with increasing total N deposition, while that of N-tolerant lichens increased. The abundance of N-sensitive lichens on trunks was reduced close to a busy road, while the abundance of N-tolerant lichens increased. The abundance of N-tolerant lichen species on trunks was lower on Quercus and other low bark pH species, but the abundance of N-sensitive lichens was similar on different tree species. Lichen abundance relationships with total N deposition did not differ between tree species or bark pH groups. The response of N-sensitive lichens to reduced nitrogen was greater than to oxidised N, and the response of N-tolerant lichens was greater to oxidised N than to reduced N. There were differences in the response of N-sensitive and N-tolerant lichens to rainfall, humidity and temperature. Relationships with N deposition and climatic variables were similar for lichen presence on twigs as for lichen abundance on trunks, but N-sensitive lichens increased, rather than decreased, on twigs of Quercus/low bark pH species. The results demonstrate the unique power of citizen science to detect and quantify the air pollution impacts over a wide geographical range, and specifically to contribute to understanding of lichen responses to different chemical forms of N deposition, local pollution sources and bark chemistry. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ionic liquid-assisted multiwalled carbon nanotube-dispersive micro-solid phase extraction for sensitive determination of inorganic As species in garlic samples by electrothermal atomic absorption spectrometry

Science.gov (United States)

Grijalba, Alexander Castro; Escudero, Leticia B.; Wuilloud, Rodolfo G.

2015-08-01

A highly sensitive dispersive micro-solid phase extraction (D-μ-SPE) method combining an ionic liquid (IL) and multi-walled carbon nanotubes (MWCNTs) for inorganic As species (As(III) and As(V)) species separation and determination in garlic samples by electrothermal atomic absorption spectrometry (ETAAS) was developed. Trihexyl(tetradecil)phosphonium chloride IL was used to form an ion pair with the arsenomolybdate complex obtained by reaction of As(V) with molybdate ion. Afterwards, 1.0 mg of MWCNTs was dispersed for As(V) extraction and the supernatant was separated by centrifugation. MWCNTs were re-dispersed with tetradecyltrimethylammonium bromide surfactant and ultrasound followed by direct injection into the graphite furnace of ETAAS for As determination. Pyrolysis and atomization conditions were carefully studied for complete decomposition of MWCNTs and IL matrices. Under optimum conditions, an extraction efficiency of 100% and a preconcentration factor of 70 were obtained with 5 mL of garlic extract. The detection limit was 7.1 ng L- 1 and the relative standard deviations (RSDs) for six replicate measurements at 5 μg L- 1 of As were 5.4% and 4.8% for As(III) and As(V), respectively. The proposed D-μ-SPE method allowed the efficient separation and determination of inorganic As species in a complex matrix such as garlic extract.

Evaluation of Relative Resistance in Thirty Dwarf Mahaleb Genotypes to Four Phytophthora Species in the Greenhouse and Garden

Directory of Open Access Journals (Sweden)

mohammad hajian

2018-01-01

Full Text Available Introduction: The best cherry rootstock for Iranian nurseries and orchards is Prunus mahaleb (L. Mill. Mahaleb is tolerant to lime-induced iron chlorosis and zinc deficiency. It is a good rootstock on light, calcareous soils and arid climates in Iran but sensitive to Phytophthora. Iran represents a significant source of germplasm of different fruit species, especially for those from the genus Prunus. Collection and research on P.mahaleb was initiated at the Horticultural Department of Khorasan Razavi Agriculture and Natural Resources Research and Education Center in 1997 for mahaleb cherry rootstock. Some researchers have reported pathogenicity of Phytophthora species (Banihashemi and Sartipi, 2004; Wilcox and Mircetich, 1985; Exadaktylou and Thomidis, 2005; Tomidis et al., 2008. This study was conducted to evaluate the susceptibility of 30 selected dwarf Mahaleb genotypes to P.nicotianae, P.citricola, P.cactorum and P. citrophthora under greenhouse and orchard conditions. Material and methods: In this study, the response of 30 selected dwarf Mahaleb genotypes (188, 171, 165, 162, 161, 155, 139, 136, 131, 120, 106, 104, 101, 100, 90, 194, 195, 199, 200, 224, 228, 247 , 249, 265, 266, 267, 268, 270, 272, 277 to disease caused by four species of the fungus Phytophthora root and crown rot were investigated under greenhouse and orchard conditions. Greenhouse experiments were performed based on Ribeiro and Baumer, 1977 and modified it by Feichtenberger et al., 1984. For evaluation the index disease was performed based on the method of Broadbent and Gollnow 1992. Orchard terials was laid out in the Toragh research station in Mashhad. Evaluation of genotypes and contamination based on Tomidis, 2001 was performed by measuring the area of necrosis. Results and discussion: In evaluating the reaction of young seedling dwarf mahaleb genotypes to four Phytophthora species under greenhouse conditions, results showed that four species of Phytophthora pathogens

Pain sensitivity is inversely related to regional grey matter density in the brain.

Science.gov (United States)

Emerson, Nichole M; Zeidan, Fadel; Lobanov, Oleg V; Hadsel, Morten S; Martucci, Katherine T; Quevedo, Alexandre S; Starr, Christopher J; Nahman-Averbuch, Hadas; Weissman-Fogel, Irit; Granovsky, Yelena; Yarnitsky, David; Coghill, Robert C

2014-03-01

Pain is a highly personal experience that varies substantially among individuals. In search of an anatomical correlate of pain sensitivity, we used voxel-based morphometry to investigate the relationship between grey matter density across the whole brain and interindividual differences in pain sensitivity in 116 healthy volunteers (62 women, 54 men). Structural magnetic resonance imaging (MRI) and psychophysical data from 10 previous functional MRI studies were used. Age, sex, unpleasantness ratings, scanner sequence, and sensory testing location were added to the model as covariates. Regression analysis of grey matter density across the whole brain and thermal pain intensity ratings at 49°C revealed a significant inverse relationship between pain sensitivity and grey matter density in bilateral regions of the posterior cingulate cortex, precuneus, intraparietal sulcus, and inferior parietal lobule. Unilateral regions of the left primary somatosensory cortex also exhibited this inverse relationship. No regions showed a positive relationship to pain sensitivity. These structural variations occurred in areas associated with the default mode network, attentional direction and shifting, as well as somatosensory processing. These findings underscore the potential importance of processes related to default mode thought and attention in shaping individual differences in pain sensitivity and indicate that pain sensitivity can potentially be predicted on the basis of brain structure. Copyright © 2013 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Development of genome- and transcriptome-derived microsatellites in related species of snapping shrimps with highly duplicated genomes.

Science.gov (United States)

Gaynor, Kaitlyn M; Solomon, Joseph W; Siller, Stefanie; Jessell, Linnet; Duffy, J Emmett; Rubenstein, Dustin R

2017-11-01

Molecular markers are powerful tools for studying patterns of relatedness and parentage within populations and for making inferences about social evolution. However, the development of molecular markers for simultaneous study of multiple species presents challenges, particularly when species exhibit genome duplication or polyploidy. We developed microsatellite markers for Synalpheus shrimp, a genus in which species exhibit not only great variation in social organization, but also interspecific variation in genome size and partial genome duplication. From the four primary clades within Synalpheus, we identified microsatellites in the genomes of four species and in the consensus transcriptome of two species. Ultimately, we designed and tested primers for 143 microsatellite markers across 25 species. Although the majority of markers were disomic, many markers were polysomic for certain species. Surprisingly, we found no relationship between genome size and the number of polysomic markers. As expected, markers developed for a given species amplified better for closely related species than for more distant relatives. Finally, the markers developed from the transcriptome were more likely to work successfully and to be disomic than those developed from the genome, suggesting that consensus transcriptomes are likely to be conserved across species. Our findings suggest that the transcriptome, particularly consensus sequences from multiple species, can be a valuable source of molecular markers for taxa with complex, duplicated genomes. © 2017 John Wiley & Sons Ltd.

Bacillus subtilis Protects Public Goods by Extending Kin Discrimination to Closely Related Species

Directory of Open Access Journals (Sweden)

Nicholas A. Lyons

2017-07-01

Full Text Available Kin discrimination systems are found in numerous communal contexts like multicellularity and are theorized to prevent exploitation of cooperative behaviors. The kin discrimination system in Bacillus subtilis differs from most other such systems because it excludes nonkin cells rather than including kin cells. Because nonkin are the target of the system, B. subtilis can potentially distinguish degrees of nonkin relatedness, not just kin versus nonkin. We examined this by testing a large strain collection of diverse Bacillus species against B. subtilis in different multicellular contexts. The effects of kin discrimination extend to nearby species, as the other subtilis clade species were treated with the same antagonism as nonkin. Species in the less-related pumilus clade started to display varied phenotypes but were mostly still discriminated against, while cereus clade members and beyond were no longer subject to kin discrimination. Seeking a reason why other species are perceived as antagonistic nonkin, we tested the ability of B. subtilis to steal communally produced surfactant from these species. We found that the species treated as nonkin were the only ones that made a surfactant that B. subtilis could utilize and that nonkin antagonism prevented such stealing when the two strains were mixed. The nonkin exclusion kin discrimination method thus allows effective protection of the cooperative behaviors prevalent in multicellularity while still permitting interactions with more distant species that are not a threat.

Lanthanide ions (III) as sensitizers of melatonin oxidation in reaction mixtures providing reactive species of oxygen and nitrogen

Energy Technology Data Exchange (ETDEWEB)

Kaczmarek, Małgorzata, E-mail: mkaczmar@amu.edu.pl

2015-06-15

Chemiluminescence (CL) of the reactive systems providing strong oxidants (reactive species of oxygen and nitrogen) containing lanthanide ions (III) and melatonin, was studied. Kinetic curves of emission decay and spectral distributions of chemiluminescence were obtained. Analysis of differences in the intensity of chemiluminescence and CL spectra proved that excitation of Tb(III) and Dy(III) ions takes place with the energy transfer from the products of melatonin oxidation: N{sup 1}-acetyl-N{sup 2}-formyl-5-methoxykynuramine (AFMK) and N{sup 1}-acetyl-5-methoxykynuramine (AMK) to the lanthanide ions. In the system Fe(II)/Fe(III)–H{sub 2}O{sub 2}–Mel–Tb(III) a linear correlation was established between the integrated CL intensity and melatonin concent. - Highlights: • Chemiluminescence (CL) of melatonin (Mel) oxidation by reactive species of oxygen and nitrogen. • Tb(III) and Dy(III) ions as sensitizers of a melatonin oxidation process. • New CL method for determination of melatonin in pharmaceutical preparations based on CL of Fe(II)/Fe(III)–H{sub 2}O{sub 2}–Mel–Tb(III) system.

Relating tree growth to rainfall in Bolivian rain forests: a test for six species using tree ring analysis.

Science.gov (United States)

Brienen, Roel J W; Zuidema, Pieter A

2005-11-01

Many tropical regions show one distinct dry season. Often, this seasonality induces cambial dormancy of trees, particularly if these belong to deciduous species. This will often lead to the formation of annual rings. The aim of this study was to determine whether tree species in the Bolivian Amazon region form annual rings and to study the influence of the total amount and seasonal distribution of rainfall on diameter growth. Ring widths were measured on stem discs of a total of 154 trees belonging to six rain forest species. By correlating ring width and monthly rainfall data we proved the annual character of the tree rings for four of our study species. For two other species the annual character was proved by counting rings on trees of known age and by radiocarbon dating. The results of the climate-growth analysis show a positive relationship between tree growth and rainfall in certain periods of the year, indicating that rainfall plays a major role in tree growth. Three species showed a strong relationship with rainfall at the beginning of the rainy season, while one species is most sensitive to the rainfall at the end of the previous growing season. These results clearly demonstrate that tree ring analysis can be successfully applied in the tropics and that it is a promising method for various research disciplines.

Girls' Rumination and Anxiety Sensitivity: Are They Related after Controlling for Girl, Maternal, and Parenting Factors?

Science.gov (United States)

Gardner, Christie; Epkins, Catherine C.

2012-01-01

Background: Rumination and anxiety sensitivity are posited cognitive vulnerabilities in the development and/or maintenance of depression and anxiety and have only been examined separately in youth. Objective: We examined the relation between rumination and anxiety sensitivity in girls, after controlling for other girl, maternal, and parenting…

Ozone risk assessment in three oak species as affected by soil water availability.

Science.gov (United States)

Hoshika, Yasutomo; Moura, Barbara; Paoletti, Elena

2018-03-01

To derive ozone (O 3 ) dose-response relationships for three European oak species (Quercus ilex, Quercus pubescens, and Quercus robur) under a range of soil water availability, an experiment was carried out with 2-year-old potted seedlings exposed to three levels of water availability in the soil and three levels of O 3 pollution for one growing season in an ozone free-air controlled exposure (FACE) facility. Total biomass losses were estimated relative to a hypothetical clean air at the pre-industrial age, i.e., at 10 ppb as daily average (M24). A stomatal conductance model was parameterized with inputs from the three species for calculating the stomatal O 3 flux. Exposure-based (M24, W126, and AOT40) and flux-based (phytotoxic O 3 dose (POD) 0-3 ) dose-response relationships were estimated and critical levels (CL) were calculated for a 5% decline of total biomass. Results show that water availability can significantly affect O 3 risk assessment. In fact, dose-response relationships calculated per individual species at each water availability level resulted in very different CLs and best metrics. In a simplified approach where species were aggregated on the basis of their O 3 sensitivity, the best metric was POD 0.5 , with a CL of 6.8 mmol m -2 for the less O 3 -sensitive species Q. ilex and Q. pubescens and of 3.5 mmol m -2 for the more O 3 -sensitive species Q. robur. The performance of POD 0 , however, was very similar to that of POD 0.5 , and thus a CL of 6.9 mmol m -2 POD 0 and 3.6 mmol m -2 POD 0 for the less and more O 3 -sensitive oak species may be also recommended. These CLs can be applied to oak ecosystems at variable water availability in the soil. We conclude that POD y is able to reconcile the effects of O 3 and soil water availability on species-specific oak productivity.

Examining Dark Triad traits in relation to sleep disturbances, anxiety sensitivity and intolerance of uncertainty in young adults.

Science.gov (United States)

Sabouri, Sarah; Gerber, Markus; Lemola, Sakari; Becker, Stephen P; Shamsi, Mahin; Shakouri, Zeinab; Sadeghi Bahmani, Dena; Kalak, Nadeem; Holsboer-Trachsler, Edith; Brand, Serge

2016-07-01

The Dark Triad (DT) describes a set of three closely related personality traits, Machiavellianism, narcissism, and psychopathy. The aim of this study was to examine the associations between DT traits, sleep disturbances, anxiety sensitivity and intolerance of uncertainty. A total of 341 adults (M=29years) completed a series of questionnaires related to the DT traits, sleep disturbances, anxiety sensitivity, and intolerance of uncertainty. A higher DT total score was associated with increased sleep disturbances, and higher scores for anxiety sensitivity and intolerance of uncertainty. In regression analyses Machiavellianism and psychopathy were predictors of sleep disturbances, anxiety sensitivity, and intolerance of uncertainty. Results indicate that specific DT traits, namely Machiavellianism and psychopathy, are associated with sleep disturbances, anxiety sensitivity and intolerance of uncertainty in young adults. Copyright © 2016 Elsevier Inc. All rights reserved.

Bacterial sensitivity to fosfomycin in pregnant women with urinary infection

Directory of Open Access Journals (Sweden)

Rodrigo Batista Souza

2015-05-01

Full Text Available The aim this study was to determine the in vitro susceptibility to fosfomycin of bacteria isolated from urine samples of pregnant women with urinary tract infection. Samples of urine culture with bacterial growth of pregnant women were collected from clinical laboratories in Tubarão, state of Santa Catarina, Brazil, between September 2012 and May 2013. In the experimental stage, the colonies were tested for sensitivity to fosfomycin by using the Kirby–Bauer method. The following information relating to the samples was also collected: patients’ age, colony count, type(s of identified bacterial(s and result of the antimicrobial sensitivity test. Student's t-test was used for mean comparison. A total of 134 samples were selected for the study. The age of the subjects ranged from 15 to 40 years (mean 26.7. Escherichia coli (Gram-negative and Staphylococcus aureus (Gram-positive were the most commonly identified species. In 89% of cases, the microorganisms were sensitive to fosfomycin. E. coli and S. aureus were the main species of bacteria responsible for urinary tract infections in women in the study area. The most prevalent microorganisms in pregnant women with urinary tract infection were susceptible to fosfomycin.

Synthetic Hexaploids Derived from Wild Species Related to Sweet Potato

OpenAIRE

SHIOTANI, Itaru; KAWASE, Tsuneo; 塩谷, 格; 川瀬, 恒男

1987-01-01

The utilization of germplasm of the wild species in sweet-potato breeding has been conducted for the last three decades. Such attempts brought some remarkable achievments in improving root yield, starch content and resistance to the nematodes of sweet potato. Some wild plants in polyploid series may have many genes potentially important for further improvement of the agronomic traits. However, the genomic relationship between the wild relatives and hexaploid sweet potato (2n=6x=90) has been u...

Monitoring the effects of atmospheric ethylene near polyethylene manufacturing plants with two sensitive plant species

International Nuclear Information System (INIS)

Tonneijck, A.E.G.; Berge, W.F. ten; Jansen, B.P.

2003-01-01

Atmospheric ethylene from polyethylene manufacturing plants adversely affected the number of flowers and growth of field-grown marigold and petunia. - Data of a multi-year (1977-1983) biomonitoring programme with marigold and petunia around polyethylene manufacturing plants was analysed to assess plant responses to atmospheric ethylene and to determine the area at risk for the phytotoxic effects of this pollutant. In both species, flower formation and growth were severely reduced close to the emission sources and plant performance improved with increasing distance. Plants exposed near the border of the research area had more flowers than the unexposed control while their growth was normal. Measurements of ethylene concentrations at a border site revealed that the growing season mean was 61.5 μg m -3 in 1982 and 15.6 μg m -3 in 1983. In terms of number of flowers, petunia was more sensitive than marigold and adverse effects were observed within ca. 400 m distance from the sources for marigold and within ca. 460 m for petunia. The area at risk (ca. 870 m) for ethylene-induced growth reduction was also limited to the industrial zone. Plants were more sensitive to ethylene in terms of growth reduction than in terms of inhibition of flowering. In the Netherlands, maximum permissible levels of ethylene are currently based on information from laboratory and greenhouse studies. Our results indicate that these levels are rather conservative in protecting field-grown plants against ethylene-induced injury near polyethylene manufacturing plants

Sensitivity and responsiveness of the health-related quality of life in stroke patients-40 (HRQOLISP-40) scale.

Science.gov (United States)

Vincent-Onabajo, Grace O; Owolabi, Mayowa O; Hamzat, Talhatu K

2014-01-01

To investigate the sensitivity and responsiveness of the Health-Related Quality of Life in Stroke Patients-40 (HRQOLISP-40) scale in evaluating stroke patients from onset to 12 months. Fifty-five patients with first-incidence stroke were followed-up for 12 months. The HRQOLISP-40 scale was used to assess health-related quality of life (HRQOL) while stroke severity was assessed with the Stroke Levity Scale. Sensitivity to change was assessed by analyzing changes in the HRQOLISP-40 scores between pairs of months with paired samples t-test. Standardized effect size (SES) and standardized response mean (SRM) were used to express responsiveness. Overall HRQOL and domains in the physical sphere of the HRQOLISP-40 were sensitive to change at different time intervals in the first 12 months post-stroke. Marked responsiveness (SES and SRM >0.7) was demonstrated by the overall scale, and the physical, psycho-emotional and cognitive domains at varying time intervals. For instance, SRM was greater than 0.7 between 1 and 6, 3 and 12, 1 and 9, and 1 and 12 months for both the physical and psycho-emotional domains. The HRQOLISP-40 is a sensitive and responsive stroke-specific quality of life measure that can be used to evaluate the outcome of stroke rehabilitation. Enhancing the health-related quality of life (HRQOL) of stroke survivors can be regarded as the ultimate goal of stroke rehabilitation. Sensitive and responsive stroke-specific HRQOL measures are required for use in evaluative studies, and clinical trials and practice. The Health-Related Quality of Life in Stroke Patients-40 (HRQOLISP-40) is a sensitive and responsive stroke-specific scale.

Antimicrobial activities, toxinogenic potential and sensitivity to ...

African Journals Online (AJOL)

Antimicrobial activities, toxinogenic potential and sensitivity to antibiotics of ... Bacillus species showed variable ability to inhibit bacterial and/or fungal species. ... to produce Mbuja in order to better control the fermentation process of Mbuja ...

Sapromyza lopesi sp. n. from Brazil: a species related to S. duodecimvittata (Frey, 1919 (Diptera: Lauxaniidae

Directory of Open Access Journals (Sweden)

G. E. Shewell

1989-01-01

Full Text Available A new species, Sapromyza lopesi, is described from Brazil, and compared with its closest relative, S. duodecimvittata (Frey. Some remarks are made on the generic classification of South American Lauxaniidae as it affects these and other species.

Native plant species suitable as bioindicators and biomonitors for airborne fluoride

International Nuclear Information System (INIS)

Weinstein, Leonard H.; Davison, Alan W.

2003-01-01

The strengths and limitations of techniques for biomonitoring and bioindicating fluorides are reviewed. - For 30-40 years airborne fluoride, usually in the form of HF or SiF 4 , was one of the most important and damaging air pollutants affecting forests, crops and natural vegetation. It is much more toxic than most other air pollutants such as O 3 or SO 2 because injury to the most sensitive species begins when they are exposed to a concentration below 1 ppb (ca. 0.8 μg m -3 ) for a 1- to 3-day period. The long-term threshold concentration is around 0.25-0.30 μg m -3 . Higher concentrations and longer durations of exposure induce much more rapid and extensive injury. However, there is a difference in sensitivity between the most and least sensitive species of around 2-3 orders of magnitude and most species possess a degree of resistance. Dramatic improvements in engineering technology have greatly reduced emissions but because of the high toxicity, cases of vegetation injury are still common, even in developed countries, and cases involving litigation still occur. Therefore there is a continuing need for bioindicators and biomonitoring of fluorides, so this paper reviews the subject, drawing attention to the strengths and limitations of the techniques. Visible symptoms are described and illustrated and tables of relative sensitivity are given and their limitations discussed. Finally, examples of biomonitoring in Europe and the USA are presented

Spectral shifts of mammalian ultraviolet-sensitive pigments (short wavelength-sensitive opsin 1) are associated with eye length and photic niche evolution.

Science.gov (United States)

Emerling, Christopher A; Huynh, Hieu T; Nguyen, Minh A; Meredith, Robert W; Springer, Mark S

2015-11-22

Retinal opsin photopigments initiate mammalian vision when stimulated by light. Most mammals possess a short wavelength-sensitive opsin 1 (SWS1) pigment that is primarily sensitive to either ultraviolet or violet light, leading to variation in colour perception across species. Despite knowledge of both ultraviolet- and violet-sensitive SWS1 classes in mammals for 25 years, the adaptive significance of this variation has not been subjected to hypothesis testing, resulting in minimal understanding of the basis for mammalian SWS1 spectral tuning evolution. Here, we gathered data on SWS1 for 403 mammal species, including novel SWS1 sequences for 97 species. Ancestral sequence reconstructions suggest that the most recent common ancestor of Theria possessed an ultraviolet SWS1 pigment, and that violet-sensitive pigments evolved at least 12 times in mammalian history. We also observed that ultraviolet pigments, previously considered to be a rarity, are common in mammals. We then used phylogenetic comparative methods to test the hypotheses that the evolution of violet-sensitive SWS1 is associated with increased light exposure, extended longevity and longer eye length. We discovered that diurnal mammals and species with longer eyes are more likely to have violet-sensitive pigments and less likely to possess UV-sensitive pigments. We hypothesize that (i) as mammals evolved larger body sizes, they evolved longer eyes, which limited transmittance of ultraviolet light to the retina due to an increase in Rayleigh scattering, and (ii) as mammals began to invade diurnal temporal niches, they evolved lenses with low UV transmittance to reduce chromatic aberration and/or photo-oxidative damage. © 2015 The Author(s).

Genomic relations among 31 species of Mammillaria haworth (Cactaceae) using random amplified polymorphic DNA.

Science.gov (United States)

Mattagajasingh, Ilwola; Mukherjee, Arup Kumar; Das, Premananda

2006-01-01

Thirty-one species of Mammillaria were selected to study the molecular phylogeny using random amplified polymorphic DNA (RAPD) markers. High amount of mucilage (gelling polysaccharides) present in Mammillaria was a major obstacle in isolating good quality genomic DNA. The CTAB (cetyl trimethyl ammonium bromide) method was modified to obtain good quality genomic DNA. Twenty-two random decamer primers resulted in 621 bands, all of which were polymorphic. The similarity matrix value varied from 0.109 to 0.622 indicating wide variability among the studied species. The dendrogram obtained from the unweighted pair group method using arithmetic averages (UPGMA) analysis revealed that some of the species did not follow the conventional classification. The present work shows the usefulness of RAPD markers for genetic characterization to establish phylogenetic relations among Mammillaria species.

Extracellular ultrathin fibers sensitive to intracellular reactive oxygen species: Formation of intercellular membrane bridges

Energy Technology Data Exchange (ETDEWEB)

Jung, Se-Hui; Park, Jin-Young; Joo, Jung-Hoon; Kim, Young-Myeong; Ha, Kwon-Soo, E-mail: ksha@kangwon.ac.kr

2011-07-15

Membrane bridges are key cellular structures involved in intercellular communication; however, dynamics for their formation are not well understood. We demonstrated the formation and regulation of novel extracellular ultrathin fibers in NIH3T3 cells using confocal and atomic force microscopy. At adjacent regions of neighboring cells, phorbol 12-myristate 13-acetate (PMA) and glucose oxidase induced ultrathin fiber formation, which was prevented by Trolox, a reactive oxygen species (ROS) scavenger. The height of ROS-sensitive ultrathin fibers ranged from 2 to 4 nm. PMA-induced formation of ultrathin fibers was inhibited by cytochalasin D, but not by Taxol or colchicine, indicating that ultrathin fibers mainly comprise microfilaments. PMA-induced ultrathin fibers underwent dynamic structural changes, resulting in formation of intercellular membrane bridges. Thus, these fibers are formed by a mechanism(s) involving ROS and involved in formation of intercellular membrane bridges. Furthermore, ultrastructural imaging of ultrathin fibers may contribute to understanding the diverse mechanisms of cell-to-cell communication and the intercellular transfer of biomolecules, including proteins and cell organelles.

Thermal sensitivity of immune function: evidence against a generalist-specialist trade-off among endothermic and ectothermic vertebrates

Science.gov (United States)

Butler, Michael W.; Stahlschmidt, Zachary R.; Ardia, Daniel R.; Davies, Scott; Davis, Jon; Guillette, Louis J.; Johnson, Nicholas; McCormick, Stephen D.; McGraw, Kevin J.; DeNardo, Dale F.

2013-01-01

Animal body temperature (Tbody) varies over daily and annual cycles, affecting multiple aspects of biological performance in both endothermic and ectothermic animals. Yet a comprehensive comparison of thermal performance among animals varying in Tbody (mean and variance) and heat production is lacking. Thus, we examined the thermal sensitivity of immune function (a crucial fitness determinant) in Vertebrata, a group encompassing species of varying thermal biology. Specifically, we investigated temperature-related variation in two innate immune performance metrics, hemagglutination and hemolysis, for 13 species across all seven major vertebrate clades. Agglutination and lysis were temperature dependent and were more strongly related to the thermal biology of species (e.g., mean Tbody) than to the phylogenetic relatedness of species, although these relationships were complex and frequently surprising (e.g., heterotherms did not exhibit broader thermal performance curves than homeotherms). Agglutination and lysis performance were positively correlated within species, except in taxa that produce squalamine, a steroidal antibiotic that does not lyse red blood cells. Interestingly, we found the antithesis of a generalist-specialist trade-off: species with broader temperature ranges of immune performance also had higher peak performance levels. In sum, we have uncovered thermal sensitivity of immune performance in both endotherms and ectotherms, highlighting the role that temperature and life history play in immune function across Vertebrata.

Variation in ploidy level and phenology can result in large and unexpected differences in demography and climatic sensitivity between closely related ferns.

NARCIS (Netherlands)

Groot, de G.A.; Zuidema, P.A.; Groot, H.; During, H.J.

2012-01-01

• Premise of the study: Current environmental changes may affect the dynamics and viability of plant populations. This environmental sensitivity may differ between species of different ploidy level because polyploidization can influence life history traits. We compared the demography and climatic

Fuelwood quality of promising tree species for alkaline soil sites in relation to tree age

Energy Technology Data Exchange (ETDEWEB)

Goel, V.L.; Behl, H.M. [National Botanical Research Inst., Lucknow (India). Biomass Research Center

1996-06-01

The fuelwood quality of five tree species suitable for afforestation of alkaline soil sites was investigated in relation to tree age for establishing harvest rotation cycles. Prosopis juliflora and Acacia nilotica were found to be the most suitable species for short rotation fuel wood forestry programmes because of their high wood density, biomass yield, low ash and moisture content, and good heat of combustion at the juvenile stage. The performance of other species like Acacia auriculiformis, Terminalia arjuna and Sesbania formosa is discussed. (author)

Effects of fluorine on the germination of some species of seeds

Energy Technology Data Exchange (ETDEWEB)

Navara, J; Holub, Z; Bedatsova, L

1966-01-01

The various degrees of tolerance of the seeds of some species of plants towards fluorine and their ability to accumulate fluorine under experimental conditions are presented. The effects of fluorine on the germination of seeds manifests itself in various ways. The studied species have been divided into four groups according to their natural tolerance: (1) very sensitive: pea, soya, vetch and cabbage; (2) sensitive: radish, barley, cole; (3) less sensitive: maize, cauliflower, alfalfa, mustard, oats, clover kohlrabi; and (4) tolerant: poppy, carrot, tomato. Highly tolerant species are capable of accumulating considerable amounts of fluorine when compared with the more sensitive species. A more intensive accumulation of fluorine has been noticed in the oleaginous species, viz. mustard and poppy. A correlation was found to exist between the ash contents (especially of calcium) and the ability of a greater accumulation of fluorine. 23 references, 6 figures, 2 tables.

Predicting community sensitivity to ozone, using Ellenberg Indicator values

Energy Technology Data Exchange (ETDEWEB)

Jones, M. Laurence M. [Centre for Ecology and Hydrology Bangor, Orton Building, Deiniol Road, Bangor, Gwynedd LL57 2UP (United Kingdom)]. E-mail: lj@ceh.ac.uk; Hayes, Felicity [Centre for Ecology and Hydrology Bangor, Orton Building, Deiniol Road, Bangor, Gwynedd LL57 2UP (United Kingdom)]. E-mail: fhay@ceh.ac.uk; Mills, Gina [Centre for Ecology and Hydrology Bangor, Orton Building, Deiniol Road, Bangor, Gwynedd LL57 2UP (United Kingdom)]. E-mail: gmi@ceh.ac.uk; Sparks, Tim H. [Centre for Ecology and Hydrology Monks Wood, Abbots Ripton, Huntingdon, Cambridgeshire PE28 2LS (United Kingdom)]. E-mail: ths@ceh.ac.uk; Fuhrer, Juerg [Swiss Federal Research Station for Agroecology and Agriculture (FAL), Air Pollution/Climate Group, Reckenholzstrasse 191, CH-8046 Zurich (Switzerland)]. E-mail: juerg.fuhrer@fal.admin.ch

2007-04-15

This paper develops a regression-based model for predicting changes in biomass of individual species exposed to ozone (RS{sub p}), based on their Ellenberg Indicator values. The equation (RS{sub p}=1.805-0.118Light-0.135Salinity) underpredicts observed sensitivity but has the advantage of widespread applicability to almost 3000 European species. The model was applied to grassland communities to develop two further predictive tools. The first tool, percentage change in biomass (ORI%) was tested on data from a field-based ozone exposure experiment and predicted a 27% decrease in biomass over 5 years compared with an observed decrease of 23%. The second tool, an index of community sensitivity to ozone (CORI), was applied to 48 grassland communities and suggests that community sensitivity to ozone is primarily species-driven. A repeat-sampling routine showed that nine species were the minimum requirement to estimate CORI within 5%.

Measurement of Retinal Sensitivity on Tablet Devices in Age-Related Macular Degeneration.

Science.gov (United States)

Wu, Zhichao; Guymer, Robyn H; Jung, Chang J; Goh, Jonathan K; Ayton, Lauren N; Luu, Chi D; Lawson, David J; Turpin, Andrew; McKendrick, Allison M

2015-06-01

We compared measurements of central retinal sensitivity on a portable, low-cost tablet device to the established method of microperimetry in age-related macular degeneration (AMD). A customized test designed to measure central retinal sensitivity (within the central 1° radius) on a tablet device was developed using an open-source platform called PsyPad. A total of 30 participants with AMD were included in this study, and all participants performed a practice test on PsyPad, followed by four tests of one eye and one test of the other eye. Participants then underwent standardized microperimetry examinations in both eyes. The average test duration on PsyPad was 53.9 ± 7.5 seconds, and no significant learning effect was observed over the examinations performed ( P = 1.000). The coefficient of repeatability of central retinal sensitivity between the first two examinations on PsyPad was ±1.76 dB. The mean central retinal sensitivity was not significantly different between PsyPad (25.7 ± 0.4 dB) and microperimetry (26.1 ± 0.4 dB, P = 0.094), and the 95% limits of agreement between the two measures were between -4.12 and 4.92 dB. The measurements of central retinal sensitivity can be performed effectively using a tablet device, displaying reasonably good agreement with those obtained using the established method of microperimetry. These findings highlight the potential of tablet devices as low-cost and portable tools for developing and performing visual function measures that can be easily and widely implemented.

Free radical scavenging reverses fructose-induced salt-sensitive hypertension

Directory of Open Access Journals (Sweden)

Zenner ZP

2017-12-01

Full Text Available Zachary P Zenner, Kevin L Gordish, William H Beierwaltes Department of Internal Medicine, Hypertension and Vascular Research Division, Henry Ford Hospital, Detroit, MI, USA Abstract: We have previously reported that a moderate dietary supplementation of 20% fructose but not glucose leads to a salt-sensitive hypertension related to increased proximal sodium–hydrogen exchanger activity and increased renal sodium retention. We also found that while high salt increased renal nitric oxide formation, this was retarded in the presence of fructose intake. We hypothesized that at least part of the pathway leading to fructose-induced salt-sensitive hypertension could be due to fructose-induced formation of reactive oxygen species and inappropriate stimulation of renin secretion, all of which would contribute to an increase in blood pressure. We found that both 20% fructose intake and a high-salt diet stimulated 8-isoprostane excretion. The superoxide dismutase (SOD mimetic tempol significantly reduced this elevated excretion. Next, we placed rats on a high-salt diet (4% for 1 week in combination with normal rat chow or 20% fructose with or without chronic tempol administration. A fructose plus high-salt diet induced a rapid increase (15 mmHg in systolic blood pressure and reversed high salt suppression of plasma renin activity. Tempol treatment reversed the pressor response and restored high salt suppression of renin. We conclude that fructose-induced salt-sensitive hypertension is driven by increased renal reactive oxygen species formation associated with salt retention and an enhanced renin–angiotensin system. Keywords: reactive oxygen species, tempol, sodium, renin, oxidative stress

Sensitivity of Bemisia Tabaci (Hemiptera: Aleyrodidae) to Several New Insecticides in China: Effects of Insecticide Type and Whitefly Species, Strain, and Stage

Science.gov (United States)

Xie, Wen; Liu, Yang; Wang, Shaoli; Wu, Qingjun; Pan, Huipeng; Yang, Xin; Guo, Litao; Zhang, Youjun

2014-01-01

Abstract Whitefly biotypes B and Q are the two most damaging members of the Bemisia tabaci (Hemiptera: Aleyrodidae) species complex. Control of B. tabaci (and especially of Q) has been impaired by resistance to commonly used insecticides. To find new insecticides for B. tabaci management in China, we investigated the sensitivity of eggs, larvae, and adults of laboratory strains of B and Q (named Lab-B and Lab-Q) and field strains of Q to several insecticides. For eggs, larvae, and adults of B. tabaci and for six insecticides (cyantraniliprole, chlorantraniliprole, pyriproxyfen, buprofezin, acetamiprid, and thiamethoxam), LC 50 values were higher for Lab-Q than for Lab-B; avermectin LC 50 values, however, were low for adults of both Lab-Q and Lab-B. Based on the laboratory results, insecticides were selected to test against eggs, larvae, and adults of four field strains of B. tabaci Q. Although the field strains differed in their sensitivity to the insecticides, the eggs and larvae of all strains were highly sensitive to cyantraniliprole, and the adults of all strains were highly sensitive to avermectin. The eggs, larvae, and adults of B. tabaci Q were generally more resistant than those of B. tabaci B to the tested insecticides. B. tabaci Q eggs and larvae were sensitive to cyantraniliprole and pyriproxyfen, whereas B. tabaci Q adults were sensitive to avermectin. Field trials should be conducted with cyantraniliprole, pyriproxyfen, and avermectin for control of B. tabaci Q and B in China. PMID:25434040

The Complete Chloroplast Genome of Wild Rice (Oryza minuta) and Its Comparison to Related Species.

Science.gov (United States)

Asaf, Sajjad; Waqas, Muhammad; Khan, Abdul L; Khan, Muhammad A; Kang, Sang-Mo; Imran, Qari M; Shahzad, Raheem; Bilal, Saqib; Yun, Byung-Wook; Lee, In-Jung

2017-01-01

Oryza minuta , a tetraploid wild relative of cultivated rice (family Poaceae), possesses a BBCC genome and contains genes that confer resistance to bacterial blight (BB) and white-backed (WBPH) and brown (BPH) plant hoppers. Based on the importance of this wild species, this study aimed to understand the phylogenetic relationships of O. minuta with other Oryza species through an in-depth analysis of the composition and diversity of the chloroplast (cp) genome. The analysis revealed a cp genome size of 135,094 bp with a typical quadripartite structure and consisting of a pair of inverted repeats separated by small and large single copies, 139 representative genes, and 419 randomly distributed microsatellites. The genomic organization, gene order, GC content and codon usage are similar to those of typical angiosperm cp genomes. Approximately 30 forward, 28 tandem and 20 palindromic repeats were detected in the O . minuta cp genome. Comparison of the complete O. minuta cp genome with another eleven Oryza species showed a high degree of sequence similarity and relatively high divergence of intergenic spacers. Phylogenetic analyses were conducted based on the complete genome sequence, 65 shared genes and matK gene showed same topologies and O. minuta forms a single clade with parental O. punctata . Thus, the complete O . minuta cp genome provides interesting insights and valuable information that can be used to identify related species and reconstruct its phylogeny.

Phylogenetic relationships among Lactuca (Asteraceae) species and related genera based on ITS-1 DNA sequences.

Science.gov (United States)

Koopman, W J; Guetta, E; van de Wiel, C C; Vosman, B; van den Berg, R G

1998-11-01

Internal transcribed spacer (ITS-1) sequences from 97 accessions representing 23 species of Lactuca and related genera were determined and used to evaluate species relationships of Lactuca sensu lato (s.l.). The ITS-1 phylogenies, calculated using PAUP and PHYLIP, correspond better to the classification of Feráková than to other classifications evaluated, although the inclusion of sect. Lactuca subsect. Cyanicae is not supported. Therefore, exclusion of subsect. Cyanicae from Lactuca sensu Feráková is proposed. The amended genus contains the entire gene pool (sensu Harlan and De Wet) of cultivated lettuce (Lactuca sativa). The position of the species in the amended classification corresponds to their position in the lettuce gene pool. In the ITS-1 phylogenies, a clade with L. sativa, L. serriola, L. dregeana, L. altaica, and L. aculeata represents the primary gene pool. L. virosa and L. saligna, branching off closest to this clade, encompass the secondary gene pool. L. virosa is possibly of hybrid origin. The primary and secondary gene pool species are classified in sect. Lactuca subsect. Lactuca. The species L. quercina, L. viminea, L. sibirica, and L. tatarica, branching off next, represent the tertiary gene pool. They are classified in Lactuca sect. Lactucopsis, sect. Phaenixopus, and sect. Mulgedium, respectively. L. perennis and L. tenerrima, classified in sect. Lactuca subsect. Cyanicae, form clades with species from related genera and are not part of the lettuce gene pool.

Olfactory sensitivity for sperm-attractant aromatic aldehydes: a comparative study in human subjects and spider monkeys.

Science.gov (United States)

Kjeldmand, Luna; Salazar, Laura Teresa Hernandez; Laska, Matthias

2011-01-01

Using a three-alternative forced-choice ascending staircase procedure, we determined olfactory detection thresholds in 20 human subjects for seven aromatic aldehydes and compared them to those of four spider monkeys tested in parallel using an operant conditioning paradigm. With all seven odorants, both species detected concentrations lyral, and 3-phenylpropanal. No significant correlation between presence/absence of an oxygen-containing moiety attached to the benzene ring or presence/absence of an additional alkyl group next to the functional aldehyde group, and olfactory sensitivity was found in any of the species. However, the presence of a tertiary butyl group in para position (relative to the functional aldehyde group) combined with a lack of an additional alkyl group next to the functional aldehyde group may be responsible for the finding that both species were most sensitive to bourgeonal.

Evidence for nonallopatric speciation among closely related sympatric Heliotropium species in the Atacama Desert.

Science.gov (United States)

Luebert, Federico; Jacobs, Pit; Hilger, Hartmut H; Muller, Ludo A H

2014-02-01

The genetic structure of populations of closely related, sympatric species may hold the signature of the geographical mode of the speciation process. In fully allopatric speciation, it is expected that genetic differentiation between species is homogeneously distributed across the genome. In nonallopatric speciation, the genomes may remain undifferentiated to a large extent. In this article, we analyzed the genetic structure of five sympatric species from the plant genus Heliotropium in the Atacama Desert. We used amplified fragment length polymorphisms (AFLPs) to characterize the genetic structure of these species and evaluate their genetic differentiation as well as the number of loci subject to positive selection using divergence outlier analysis (DOA). The five species form distinguishable groups in the genetic space, with zones of overlap, indicating that they are possibly not completely isolated. Among-species differentiation accounts for 35% of the total genetic differentiation (F ST = 0.35), and F ST between species pairs is positively correlated with phylogenetic distance. DOA suggests that few loci are subject to positive selection, which is in line with a scenario of nonallopatric speciation. These results support the idea that sympatric species of Heliotropium sect. Cochranea are under an ongoing speciation process, characterized by a fluctuation of population ranges in response to pulses of arid and humid periods during Quaternary times.

Life history affects how species experience succession in pen shell metacommunities.

Science.gov (United States)

Munguia, Pablo

2014-04-01

In nature, very few species are common and broadly distributed. Most species are rare and occupy few sites; this pattern is ubiquitous across habitats and taxa. In spatially structured communities (metacommunities), regional distribution and local abundance may change as the relative effects of within-habitat processes (e.g., species interactions) and among-habitat processes (e.g., dispersal) may vary through succession. A field experiment with the marine benthic inhabitants of pen shells (Atrina rigida) tested how common and rare species respond to succession and metacommunity size. I followed community development through time and partitioned species into sessile and motile based on their natural history. Rare species drive diversity patterns and are influenced by metacommunity size: there are strong abundance-distribution differences between common and rare species in large metacommunities, but motile species show lower rates of change than sessile species. In small metacommunities both common and rare species have similar changes through time; the dichotomous distinction of common and rare species is not present. Edge effects in metacommunities affect species' changes in distribution and abundance. In large metacommunities diversity is higher in edge habitats relative to small metacommunities during early succession. However, edge effects benefit motile species over time in small metacommunities showing a rapid increase in diversity. Individual mobility is sensitive to regional community size and allows individuals to sort among different communities. In contrast, sessile species do not show this edge effect. Metacommunity theory is a useful framework for understanding spatially structured communities, but the natural history of coexisting species cannot be ignored.

Closely related freshwater macrophyte species, Ceratophyllum demersum and C. submersum, differ in temperature response

DEFF Research Database (Denmark)

Hyldgaard, Benita; Sorrell, Brian Keith; Brix, Hans

2014-01-01

1. The importance of temperature responses of photosynthesis and respiration in determining species distributions was compared in two closely related freshwater macrophytes, Ceratophyllum demersum and C. submersum. The two species differed significantly in response to temperature in the short...... and distributional patterns corresponded well with the long-term (weeks) results obtained, but with some important deviations. The long-term responses of the two species to low temperature (12 °C) were more similar than expected. In contrast, high temperature (35 °C), which stimulated photosynthesis in C. submersum...... in the short term, inhibited photosynthesis in the long term and resulted in lower growth rates of C. submersum, both compared to C. demersum and to growth rates at intermediate temperatures (18 and 25 °C). 3. The long-term acclimation strategy differed between the two species. Ceratophyllum demersum achieved...

Are leaf physiological traits related to leaf water isotopic enrichment in restinga woody species?

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BRUNO H.P. ROSADO

2013-09-01

Full Text Available During plant-transpiration, water molecules having the lighter stable isotopes of oxygen and hydrogen evaporate and diffuse at a faster rate through the stomata than molecules having the heavier isotopes, which cause isotopic enrichment of leaf water. Although previous models have assumed that leaf water is well-mixed and isotopically uniform, non-uniform stomatal closure, promoting different enrichments between cells, and different pools of water within leaves, due to morpho-physiological traits, might lead to inaccuracies in isotopic models predicting leaf water enrichment. We evaluate the role of leaf morpho-physiological traits on leaf water isotopic enrichment in woody species occurring in a coastal vegetation of Brazil known as restinga. Hydrogen and oxygen stable isotope values of soil, plant stem and leaf water and leaf traits were measured in six species from restinga vegetation during a drought and a wet period. Leaf water isotopic enrichment relative to stem water was more homogeneous among species during the drought in contrast to the wet period suggesting convergent responses to deal to temporal heterogeneity in water availability. Average leaf water isotopic enrichment relative to stem water during the drought period was highly correlated with relative apoplastic water content. We discuss this observation in the context of current models of leaf water isotopic enrichment as a function of the Péclet effect. We suggest that future studies should include relative apoplastic water content in isotopic models.

Are leaf physiological traits related to leaf water isotopic enrichment in restinga woody species?

Science.gov (United States)

Rosado, Bruno H P; De Mattos, Eduardo A; Sternberg, Leonel Da S L

2013-09-01

During plant-transpiration, water molecules having the lighter stable isotopes of oxygen and hydrogen evaporate and diffuse at a faster rate through the stomata than molecules having the heavier isotopes, which cause isotopic enrichment of leaf water. Although previous models have assumed that leaf water is well-mixed and isotopically uniform, non-uniform stomatal closure, promoting different enrichments between cells, and different pools of water within leaves, due to morpho-physiological traits, might lead to inaccuracies in isotopic models predicting leaf water enrichment. We evaluate the role of leaf morpho-physiological traits on leaf water isotopic enrichment in woody species occurring in a coastal vegetation of Brazil known as restinga. Hydrogen and oxygen stable isotope values of soil, plant stem and leaf water and leaf traits were measured in six species from restinga vegetation during a drought and a wet period. Leaf water isotopic enrichment relative to stem water was more homogeneous among species during the drought in contrast to the wet period suggesting convergent responses to deal to temporal heterogeneity in water availability. Average leaf water isotopic enrichment relative to stem water during the drought period was highly correlated with relative apoplastic water content. We discuss this observation in the context of current models of leaf water isotopic enrichment as a function of the Péclet effect. We suggest that future studies should include relative apoplastic water content in isotopic models.

Cognitive Performance Is Related to Central Sensitization and Health-related Quality of Life in Patients with Chronic Whiplash-Associated Disorders and Fibromyalgia.

Science.gov (United States)

Coppieters, Iris; Ickmans, Kelly; Cagnie, Barbara; Nijs, Jo; De Pauw, Robby; Noten, Suzie; Meeus, Mira

2015-01-01

A growing body of research has demonstrated that impaired central pain modulation or central sensitization (CS) is a crucial mechanism for the development of persistent pain in chronic whiplash-associated disorders (WAD) and fibromyalgia (FM) patients. Furthermore, there is increasing evidence for cognitive dysfunctions among these patients. In addition, chronic WAD and FM patients often report problems with health-related quality of life (QoL). Yet, there is limited research concerning the interrelations between cognitive performance, indices of CS, and health-related QoL in these patients. (1) Examining the presence of cognitive impairment, CS, and limitations on health-related QoL in patients with chronic WAD and FM compared to healthy controls. (2) Examining interrelations between performance-based cognitive functioning, CS, and self-reported health-related QoL in these 3 study groups. A case-control study was conducted. The present study took place at the University Hospital Brussels, the University of Brussels, and the University of Antwerp. Fifty-nine patients (16 chronic WAD patients, 21 FM patients, and 22 pain-free volunteers) filled out the Short Form 36 item Health Survey (SF-36), a self-reported psychosocial questionnaire, to assess health-related QoL. Next, they were subjected to various pain measurements (pressure hyperalgesia, deep-tissue hyperalgesia, temporal summation [TS], and conditioned pain modulation [CPM]). Finally, participants completed a battery of performance-based cognitive tests (Stroop task, psychomotor vigilance task [PVT], and operation span task [OSPAN]). Significant cognitive impairment, bottom-up sensitization, and decreased health-related QoL were demonstrated in patients with chronic WAD and FM compared to healthy controls (P fibromyalgia, whiplash, central sensitization, conditioned pain modulation, temporal summation, cognition, quality of life.

Response to the eruption of Mount Pinatubo in relation to climate sensitivity in the CMIP3 models

Energy Technology Data Exchange (ETDEWEB)

Bender, Frida A.M.; Ekman, Annica M.L.; Rodhe, Henning [Stockholm University, Department of Meteorology, Stockholm (Sweden)

2010-10-15

The radiative flux perturbations and subsequent temperature responses in relation to the eruption of Mount Pinatubo in 1991 are studied in the ten general circulation models incorporated in the Coupled Model Intercomparison Project, phase 3 (CMIP3), that include a parameterization of volcanic aerosol. Models and observations show decreases in global mean temperature of up to 0.5 K, in response to radiative perturbations of up to 10 W m{sup -2}, averaged over the tropics. The time scale representing the delay between radiative perturbation and temperature response is determined by the slow ocean response, and is estimated to be centered around 4 months in the models. Although the magnitude of the temperature response to a volcanic eruption has previously been used as an indicator of equilibrium climate sensitivity in models, we find these two quantities to be only weakly correlated. This may partly be due to the fact that the size of the volcano-induced radiative perturbation varies among the models. It is found that the magnitude of the modelled radiative perturbation increases with decreasing climate sensitivity, with the exception of one outlying model. Therefore, we scale the temperature perturbation by the radiative perturbation in each model, and use the ratio between the integrated temperature perturbation and the integrated radiative perturbation as a measure of sensitivity to volcanic forcing. This ratio is found to be well correlated with the model climate sensitivity, more sensitive models having a larger ratio. Further, if this correspondence between ''volcanic sensitivity'' and sensitivity to CO{sub 2} forcing is a feature not only among the models, but also of the real climate system, the alleged linear relation can be used to estimate the real climate sensitivity. The observational value of the ratio signifying volcanic sensitivity is hereby estimated to correspond to an equilibrium climate sensitivity, i.e. equilibrium temperature

Biological legacies buffer local species extinction after logging.

Science.gov (United States)

Rudolphi, Jörgen; Jönsson, Mari T; Gustafsson, Lena; Bugmann, H

2014-02-01

Clearcutting has been identified as a main threat to forest biodiversity. In the last few decades, alternatives to clearcutting have gained much interest. Living and dead trees are often retained after harvest to serve as structural legacies to mitigate negative effects of forestry. However, this practice is widely employed without information from systematic before-after control-impact studies to assess the processes involved in species responses after clearcutting with retention. We performed a large-scale survey of the occurrence of logging-sensitive and red-listed bryophytes and lichens before and after clearcutting with the retention approach. A methodology was adopted that, for the first time in studies on retention approaches, enabled monitoring of location-specific substrates. We used uncut stands as controls to assess the variables affecting the survival of species after a major disturbance. In total, 12 bryophyte species and 27 lichen species were analysed. All were classified as sensitive to logging, and most species are also currently red-listed. We found that living and dead trees retained after final harvest acted as refugia in which logging-sensitive species were able to survive for 3 to 7 years after logging. Depending on type of retention and organism group, between 35% and 92% of the species occurrences persisted on retained structures. Most species observed outside retention trees or patches disappeared. Larger pre-harvest population sizes of bryophytes on dead wood increased the survival probability of the species and hence buffered the negative effects of logging. Synthesis and applications . Careful spatial planning of retention structures is required to fully embrace the habitats of logging-sensitive species. Bryophytes and lichens persisted to a higher degree in retention patches compared to solitary trees or in the clearcut area. Retaining groups of trees in logged areas will help to sustain populations of species over the clearcut phase

Remote sensing of species diversity using Landsat 8 spectral variables

Science.gov (United States)

Madonsela, Sabelo; Cho, Moses Azong; Ramoelo, Abel; Mutanga, Onisimo

2017-11-01

The application of remote sensing in biodiversity estimation has largely relied on the Normalized Difference Vegetation Index (NDVI). The NDVI exploits spectral information from red and near infrared bands of Landsat images and it does not consider canopy background conditions hence it is affected by soil brightness which lowers its sensitivity to vegetation. As such NDVI may be insufficient in explaining tree species diversity. Meanwhile, the Landsat program also collects essential spectral information in the shortwave infrared (SWIR) region which is related to plant properties. The study was intended to: (i) explore the utility of spectral information across Landsat-8 spectrum using the Principal Component Analysis (PCA) and estimate alpha diversity (α-diversity) in the savannah woodland in southern Africa, and (ii) define the species diversity index (Shannon (H‧), Simpson (D2) and species richness (S) - defined as number of species in a community) that best relates to spectral variability on the Landsat-8 Operational Land Imager dataset. We designed 90 m × 90 m field plots (n = 71) and identified all trees with a diameter at breast height (DbH) above 10 cm. H‧, D2 and S were used to quantify tree species diversity within each plot and the corresponding spectral information on all Landsat-8 bands were extracted from each field plot. A stepwise linear regression was applied to determine the relationship between species diversity indices (H‧, D2 and S) and Principal Components (PCs), vegetation indices and Gray Level Co-occurrence Matrix (GLCM) texture layers with calibration (n = 46) and test (n = 23) datasets. The results of regression analysis showed that the Simple Ratio Index derivative had a higher relationship with H‧, D2 and S (r2= 0.36; r2= 0.41; r2= 0.24 respectively) compared to NDVI, EVI, SAVI or their derivatives. Moreover the Landsat-8 derived PCs also had a higher relationship with H‧ and D2 (r2 of 0.36 and 0.35 respectively) than the

Monitoring the effects of atmospheric ethylene near polyethylene manufacturing plants with two sensitive plant species

Energy Technology Data Exchange (ETDEWEB)

Tonneijck, A.E.G.; Berge, W.F. ten; Jansen, B.P

2003-05-01

Atmospheric ethylene from polyethylene manufacturing plants adversely affected the number of flowers and growth of field-grown marigold and petunia. - Data of a multi-year (1977-1983) biomonitoring programme with marigold and petunia around polyethylene manufacturing plants was analysed to assess plant responses to atmospheric ethylene and to determine the area at risk for the phytotoxic effects of this pollutant. In both species, flower formation and growth were severely reduced close to the emission sources and plant performance improved with increasing distance. Plants exposed near the border of the research area had more flowers than the unexposed control while their growth was normal. Measurements of ethylene concentrations at a border site revealed that the growing season mean was 61.5 {mu}g m{sup -3} in 1982 and 15.6 {mu}g m{sup -3} in 1983. In terms of number of flowers, petunia was more sensitive than marigold and adverse effects were observed within ca. 400 m distance from the sources for marigold and within ca. 460 m for petunia. The area at risk (ca. 870 m) for ethylene-induced growth reduction was also limited to the industrial zone. Plants were more sensitive to ethylene in terms of growth reduction than in terms of inhibition of flowering. In the Netherlands, maximum permissible levels of ethylene are currently based on information from laboratory and greenhouse studies. Our results indicate that these levels are rather conservative in protecting field-grown plants against ethylene-induced injury near polyethylene manufacturing plants.

Sound-by-sound thalamic stimulation modulates midbrain auditory excitability and relative binaural sensitivity in frogs.

Science.gov (United States)

Ponnath, Abhilash; Farris, Hamilton E

2014-01-01

Descending circuitry can modulate auditory processing, biasing sensitivity to particular stimulus parameters and locations. Using awake in vivo single unit recordings, this study tested whether electrical stimulation of the thalamus modulates auditory excitability and relative binaural sensitivity in neurons of the amphibian midbrain. In addition, by using electrical stimuli that were either longer than the acoustic stimuli (i.e., seconds) or presented on a sound-by-sound basis (ms), experiments addressed whether the form of modulation depended on the temporal structure of the electrical stimulus. Following long duration electrical stimulation (3-10 s of 20 Hz square pulses), excitability (spikes/acoustic stimulus) to free-field noise stimuli decreased by 32%, but returned over 600 s. In contrast, sound-by-sound electrical stimulation using a single 2 ms duration electrical pulse 25 ms before each noise stimulus caused faster and varied forms of modulation: modulation lasted sound-by-sound electrical stimulation varied between different acoustic stimuli, including for different male calls, suggesting modulation is specific to certain stimulus attributes. For binaural units, modulation depended on the ear of input, as sound-by-sound electrical stimulation preceding dichotic acoustic stimulation caused asymmetric modulatory effects: sensitivity shifted for sounds at only one ear, or by different relative amounts for both ears. This caused a change in the relative difference in binaural sensitivity. Thus, sound-by-sound electrical stimulation revealed fast and ear-specific (i.e., lateralized) auditory modulation that is potentially suited to shifts in auditory attention during sound segregation in the auditory scene.

Relations of Environmental Factors with Mussel-Species Richness in the Neversink River, New York