A New Pixels Flipping Method for Huge Watermarking Capacity of the Invoice Font Image

Directory of Open Access Journals (Sweden)

Li Li

2014-01-01

Full Text Available Invoice printing just has two-color printing, so invoice font image can be seen as binary image. To embed watermarks into invoice image, the pixels need to be flipped. The more huge the watermark is, the more the pixels need to be flipped. We proposed a new pixels flipping method in invoice image for huge watermarking capacity. The pixels flipping method includes one novel interpolation method for binary image, one flippable pixels evaluation mechanism, and one denoising method based on gravity center and chaos degree. The proposed interpolation method ensures that the invoice image keeps features well after scaling. The flippable pixels evaluation mechanism ensures that the pixels keep better connectivity and smoothness and the pattern has highest structural similarity after flipping. The proposed denoising method makes invoice font image smoother and fiter for human vision. Experiments show that the proposed flipping method not only keeps the invoice font structure well but also improves watermarking capacity.

A new pixels flipping method for huge watermarking capacity of the invoice font image.

Science.gov (United States)

Li, Li; Hou, Qingzheng; Lu, Jianfeng; Xu, Qishuai; Dai, Junping; Mao, Xiaoyang; Chang, Chin-Chen

2014-01-01

Invoice printing just has two-color printing, so invoice font image can be seen as binary image. To embed watermarks into invoice image, the pixels need to be flipped. The more huge the watermark is, the more the pixels need to be flipped. We proposed a new pixels flipping method in invoice image for huge watermarking capacity. The pixels flipping method includes one novel interpolation method for binary image, one flippable pixels evaluation mechanism, and one denoising method based on gravity center and chaos degree. The proposed interpolation method ensures that the invoice image keeps features well after scaling. The flippable pixels evaluation mechanism ensures that the pixels keep better connectivity and smoothness and the pattern has highest structural similarity after flipping. The proposed denoising method makes invoice font image smoother and fiter for human vision. Experiments show that the proposed flipping method not only keeps the invoice font structure well but also improves watermarking capacity.

Endophytic actinobacteria of medicinal plants: diversity and bioactivity.

Science.gov (United States)

Golinska, Patrycja; Wypij, Magdalena; Agarkar, Gauravi; Rathod, Dnyaneshwar; Dahm, Hanna; Rai, Mahendra

2015-08-01

Endophytes are the microorganisms that exist inside the plant tissues without having any negative impact on the host plant. Medicinal plants constitute the huge diversity of endophytic actinobacteria of economical importance. These microbes have huge potential to synthesis of numerous novel compounds that can be exploited in pharmaceutical, agricultural and other industries. It is of prime importance to focus the present research on practical utilization of this microbial group in order to find out the solutions to the problems related to health, environment and agriculture. An extensive characterization of diverse population of endophytic actinobacteria associated with medicinal plants can provide a greater insight into the plant-endophyte interactions and evolution of mutualism. In the present review, we have discussed the diversity of endophytic actinobacteria of from medicinal plants their multiple bioactivities.

Genetic diversity within a dominant plant outweighs plant species diversity in structuring an arthropod community.

Science.gov (United States)

Crawford, Kerri M; Rudgers, Jennifer A

2013-05-01

Plant biodiversity is being lost at a rapid rate. This has spurred much interest in elucidating the consequences of this loss for higher trophic levels. Experimental tests have shown that both plant species diversity and genetic diversity within a plant species can influence arthropod community structure. However, the majority of these studies have been conducted in separate systems, so their relative importance is currently unresolved. Furthermore, potential interactions between the two levels of diversity, which likely occur in natural systems, have not been investigated. To clarify these issues, we conducted three experiments in a freshwater sand dune ecosystem. We (1) independently manipulated plant species diversity, (2) independently manipulated genetic diversity within the dominant plant species, Ammophila breviligulata, and (3) jointly manipulated genetic diversity within the dominant plant and species diversity. We found that genetic diversity within the dominant plant species, Ammophila breviligulata, more strongly influenced arthropod communities than plant species diversity, but this effect was dependent on the presence of other species. In species mixtures, A. breviligulata genetic diversity altered overall arthropod community composition, and arthropod richness and abundance peaked at the highest level of genetic diversity. Positive nonadditive effects of diversity were detected, suggesting that arthropods respond to emergent properties of diverse plant communities. However, in the independent manipulations where A. breviligulata was alone, effects of genetic diversity were weaker, with only arthropod richness responding. In contrast, plant species diversity only influenced arthropods when A. breviligulata was absent, and then only influenced herbivore abundance. In addition to showing that genetic diversity within a dominant plant species can have large effects on arthropod community composition, these results suggest that understanding how species

Structural diversity effect on hashtag adoption in Twitter

Science.gov (United States)

Zhang, Aihua; Zheng, Mingxing; Pang, Bowen

2018-03-01

With online social network developing rapidly these years, user' behavior in online social network has attracted a lot of attentions to it. In this paper, we study Twitter user's behavior of hashtag adoption from the perspective of social contagion and focus on "structure diversity" effect on individual's behavior in Twitter. We achieve data through Twitter's API by crawling and build a users' network to carry on empirical research. The Girvan-Newman (G-N) algorithm is used to analyze the structural diversity of user's ego network, and Logistic regression model is adopted to examine the hypothesis. The findings of our empirical study indicate that user' behavior in online social network is indeed influenced by his friends and his decision is significantly affected by the number of groups that these friends belong to, which we call structural diversity.

Archaeal Viruses: Diversity, Replication, and Structure.

Science.gov (United States)

Dellas, Nikki; Snyder, Jamie C; Bolduc, Benjamin; Young, Mark J

2014-11-01

The Archaea-and their viruses-remain the most enigmatic of life's three domains. Once thought to inhabit only extreme environments, archaea are now known to inhabit diverse environments. Even though the first archaeal virus was described over 40 years ago, only 117 archaeal viruses have been discovered to date. Despite this small number, these viruses have painted a portrait of enormous morphological and genetic diversity. For example, research centered around the various steps of the archaeal virus life cycle has led to the discovery of unique mechanisms employed by archaeal viruses during replication, maturation, and virion release. In many instances, archaeal virus proteins display very low levels of sequence homology to other proteins listed in the public database, and therefore, structural characterization of these proteins has played an integral role in functional assignment. These structural studies have not only provided insights into structure-function relationships but have also identified links between viruses across all three domains of life.

The structure of cross-cultural musical diversity

Science.gov (United States)

Rzeszutek, Tom; Savage, Patrick E.; Brown, Steven

2012-01-01

Human cultural traits, such as languages, musics, rituals and material objects, vary widely across cultures. However, the majority of comparative analyses of human cultural diversity focus on between-culture variation without consideration for within-culture variation. In contrast, biological approaches to genetic diversity, such as the analysis of molecular variance (AMOVA) framework, partition genetic diversity into both within- and between-population components. We attempt here for the first time to quantify both components of cultural diversity by applying the AMOVA model to music. By employing this approach with 421 traditional songs from 16 Austronesian-speaking populations, we show that the vast majority of musical variability is due to differences within populations rather than differences between. This demonstrates a striking parallel to the structure of genetic diversity in humans. A neighbour-net analysis of pairwise population musical divergence shows a large amount of reticulation, indicating the pervasive occurrence of borrowing and/or convergent evolution of musical features across populations. PMID:22072606

The structure of cross-cultural musical diversity.

Science.gov (United States)

Rzeszutek, Tom; Savage, Patrick E; Brown, Steven

2012-04-22

Human cultural traits, such as languages, musics, rituals and material objects, vary widely across cultures. However, the majority of comparative analyses of human cultural diversity focus on between-culture variation without consideration for within-culture variation. In contrast, biological approaches to genetic diversity, such as the analysis of molecular variance (AMOVA) framework, partition genetic diversity into both within- and between-population components. We attempt here for the first time to quantify both components of cultural diversity by applying the AMOVA model to music. By employing this approach with 421 traditional songs from 16 Austronesian-speaking populations, we show that the vast majority of musical variability is due to differences within populations rather than differences between. This demonstrates a striking parallel to the structure of genetic diversity in humans. A neighbour-net analysis of pairwise population musical divergence shows a large amount of reticulation, indicating the pervasive occurrence of borrowing and/or convergent evolution of musical features across populations.

Huge cystic craniopharyngioma with unusual extensions

Energy Technology Data Exchange (ETDEWEB)

Kitano, I.; Yoneda, K.; Yamakawa, Y.; Fukui, M.; Kinoshita, K.

1981-09-01

The findings on computed tomography (CT) of a huge cystic craniopharyngioma in a 3-year-old girl are described. The cyst occupied both anterior cranial fossae and a part of it extended to the region of the third ventricle which was displaced posteriorly. The tumor showed no contrast enhancement after the intravenous administration of contrast medium.

Genetic diversity and population structure of maize landraces from ...

African Journals Online (AJOL)

Genetic diversity and population structure of maize landraces from Côte ... However, no study on the genetic diversity of the species has been performed to date. ... The cross between two individuals from different groups might help exploit the ...

Genetics, Genomics and Evolution of Ergot Alkaloid Diversity

Directory of Open Access Journals (Sweden)

Carolyn A. Young

2015-04-01

Full Text Available The ergot alkaloid biosynthesis system has become an excellent model to study evolutionary diversification of specialized (secondary metabolites. This is a very diverse class of alkaloids with various neurotropic activities, produced by fungi in several orders of the phylum Ascomycota, including plant pathogens and protective plant symbionts in the family Clavicipitaceae. Results of comparative genomics and phylogenomic analyses reveal multiple examples of three evolutionary processes that have generated ergot-alkaloid diversity: gene gains, gene losses, and gene sequence changes that have led to altered substrates or product specificities of the enzymes that they encode (neofunctionalization. The chromosome ends appear to be particularly effective engines for gene gains, losses and rearrangements, but not necessarily for neofunctionalization. Changes in gene expression could lead to accumulation of various pathway intermediates and affect levels of different ergot alkaloids. Genetic alterations associated with interspecific hybrids of Epichloë species suggest that such variation is also selectively favored. The huge structural diversity of ergot alkaloids probably represents adaptations to a wide variety of ecological situations by affecting the biological spectra and mechanisms of defense against herbivores, as evidenced by the diverse pharmacological effects of ergot alkaloids used in medicine.

Genetic diversity and structure found in samples of Eritrean bread wheat

DEFF Research Database (Denmark)

Desta, Zeratsion Abera; Orabi, Jihad; Jahoor, Ahmed

2014-01-01

Genetic diversity and structure plays a key role in the selection of parents for crosses in plant breeding programmes. The aim of the present study was to analyse the genetic diversity and structure of Eritrean bread wheat accessions. We analysed 284 wheat accessions from Eritrea using 30 simple...... sequence repeat markers. A total of 539 alleles were detected. The allele number per locus ranged from 2 to 21, with a mean allele number of 9.2. The average genetic diversity index was 0.66, with values ranging from 0.01 to 0.89. Comparing the three genomes of wheat, the B genome had the highest genetic...... diversity (0.66) and the D genome the lowest diversity (0.61). A STRUCTURE analysis based on the Bayesian model-based cluster analysis followed by a graphical representation of the distances by non-parametric multidimensional scaling revealed a distinct partition of the Eritrean wheat accessions into two...

Genetic diversity of Begonia versicolor (Begoniaceae, a narrow endemic species in southeast Yunnan of China

Directory of Open Access Journals (Sweden)

Chun Li

2018-03-01

Full Text Available Begonia versicolor Irmscher, a narrow endemic Begonia species in southeast Yunnan of China, is a wonderful ornamental plant with huge diversity in colored foliage. To investigate its variations, the genetic diversity and population structure were studied based on 56 individuals sampled from four localities using 12 polymorphic microsatellite loci transferred from other species of Begonia. The results showed a relatively low level of genetic diversity in B. versicolor comparing with other species of Begonia using microsatellite. Positive inbreeding coefficient (FIS values were found in three populations (SWC, XPZ and DSD. AMOVA analysis indicated that genetic variations occurred mainly within populations (55.9% rather than among populations (9.7% and among groups (34.4%. Four populations were grouped into two clusters based on STRUCTURE. AMOVA and STRUCTURE analysis showed a high level and significant genetic differentiation in the populations of B. versicolor. Based on its genetic status and rarity in the wild, the sustainable in-situ and ex-situ conservation strategies should be urgently carried out to protect this species with high horticultural and scientific values.

Structural Analysis of the Resident Assistant Cultural Diversity Questionnaire

Science.gov (United States)

Johnson, Vanessa D.; Kang, Young-Shin; Thompson, George F.

2011-01-01

This study investigated the five-factor structure of the Resident Assistant Cultural Diversity (RACD) instrument, which assesses resident assistant (RA) confidence in addressing issues of cultural diversity in college and university residence halls. The instrument has five components that explore RA confidence: (1) belief in the need for cultural…

Huge uterine-cervical diverticulum mimicking as a cyst

Directory of Open Access Journals (Sweden)

S Chufal

2012-01-01

Full Text Available Here we report an incidental huge uterine-cervical diverticulum from a total abdominal hysterectomy specimen in a perimenopausal woman who presented with acute abdominal pain. The diverticulum was mimicking with various cysts present in the lateral side of the female genital tract. Histopathological examination confirmed this to be a cervical diverticulum with communication to uterine cavity through two different openings. They can attain huge size if left ignored for long duration and present a diagnostic challenge to clinicians, radiologists, as well as pathologists because of its extreme rarity. Therefore, diverticula should also be included as a differential diagnosis. Its histopathological confirmation also highlights that diverticula can present as an acute abdomen, requiring early diagnosis with appropriate timely intervention. Immunohistochemistry CD 10 has also been used to differentiate it from a mesonephric cyst.

Community structure and diversity of macrobenthic invertebrates in ...

African Journals Online (AJOL)

Macrobenthic invertebrates' community structure and diversity in relation to ... Analysis of variance (ANOVA) revealed that there were significant difference ... invertebrates' species distribution and some measured environmental variables.

Connecting slow earthquakes to huge earthquakes

OpenAIRE

Obara, Kazushige; Kato, Aitaro

2016-01-01

Slow earthquakes are characterized by a wide spectrum of fault slip behaviors and seismic radiation patterns that differ from those of traditional earthquakes. However, slow earthquakes and huge megathrust earthquakes can have common slip mechanisms and are located in neighboring regions of the seismogenic zone. The frequent occurrence of slow earthquakes may help to reveal the physics underlying megathrust events as useful analogs. Slow earthquakes may function as stress meters because of th...

Polycyclic Polyprenylated Acylphloroglucinol Congeners Possessing Diverse Structures from Hypericum henryi.

Science.gov (United States)

Yang, Xing-Wei; Li, Ming-Ming; Liu, Xia; Ferreira, Daneel; Ding, Yuanqing; Zhang, Jing-Jing; Liao, Yang; Qin, Hong-Bo; Xu, Gang

2015-04-24

Polycyclic polyprenylated acylphloroglucinols (PPAPs) are a class of hybrid natural products sharing the mevalonate/methylerythritol phosphate and polyketide biosynthetic pathways and showing considerable structural and bioactive diversity. In a systematic phytochemical investigation of Hypericum henryi, 40 PPAP-type derivatives, including the new compounds hyphenrones G-Q, were obtained. These compounds represent 12 different structural types, including four unusual skeletons exemplified by 5, 8, 10, and 17. The 12 different core structures found are explicable in terms of their biosynthetic origin. The structure of a known PPAP, perforatumone, was revised to hyphenrone A (5) by NMR spectroscopic and biomimetic synthesis methods. Several compounds exhibited inhibitory activities against acetylcholinesterase and human tumor cell lines. This study deals with the structural diversity, function, and biogenesis of natural PPAPs.

Genomic patterns in Acropora cervicornis show extensive population structure and variable genetic diversity.

Science.gov (United States)

Drury, Crawford; Schopmeyer, Stephanie; Goergen, Elizabeth; Bartels, Erich; Nedimyer, Ken; Johnson, Meaghan; Maxwell, Kerry; Galvan, Victor; Manfrino, Carrie; Lirman, Diego

2017-08-01

Threatened Caribbean coral communities can benefit from high-resolution genetic data used to inform management and conservation action. We use Genotyping by Sequencing (GBS) to investigate genetic patterns in the threatened coral, Acropora cervicornis , across the Florida Reef Tract (FRT) and the western Caribbean. Results show extensive population structure at regional scales and resolve previously unknown structure within the FRT. Different regions also exhibit up to threefold differences in genetic diversity (He), suggesting targeted management based on the goals and resources of each population is needed. Patterns of genetic diversity have a strong spatial component, and our results show Broward and the Lower Keys are among the most diverse populations in Florida. The genetic diversity of Caribbean staghorn coral is concentrated within populations and within individual reefs (AMOVA), highlighting the complex mosaic of population structure. This variance structure is similar over regional and local scales, which suggests that in situ nurseries are adequately capturing natural patterns of diversity, representing a resource that can replicate the average diversity of wild assemblages, serving to increase intraspecific diversity and potentially leading to improved biodiversity and ecosystem function. Results presented here can be translated into specific goals for the recovery of A. cervicornis , including active focus on low diversity areas, protection of high diversity and connectivity, and practical thresholds for responsible restoration.

Constructing Optimal Coarse-Grained Sites of Huge Biomolecules by Fluctuation Maximization.

Science.gov (United States)

Li, Min; Zhang, John Zenghui; Xia, Fei

2016-04-12

Coarse-grained (CG) models are valuable tools for the study of functions of large biomolecules on large length and time scales. The definition of CG representations for huge biomolecules is always a formidable challenge. In this work, we propose a new method called fluctuation maximization coarse-graining (FM-CG) to construct the CG sites of biomolecules. The defined residual in FM-CG converges to a maximal value as the number of CG sites increases, allowing an optimal CG model to be rigorously defined on the basis of the maximum. More importantly, we developed a robust algorithm called stepwise local iterative optimization (SLIO) to accelerate the process of coarse-graining large biomolecules. By means of the efficient SLIO algorithm, the computational cost of coarse-graining large biomolecules is reduced to within the time scale of seconds, which is far lower than that of conventional simulated annealing. The coarse-graining of two huge systems, chaperonin GroEL and lengsin, indicates that our new methods can coarse-grain huge biomolecular systems with up to 10,000 residues within the time scale of minutes. The further parametrization of CG sites derived from FM-CG allows us to construct the corresponding CG models for studies of the functions of huge biomolecular systems.

Genetic diversity and population structure of sweet cassava using ...

African Journals Online (AJOL)

The objective of this study was to evaluate the population structure and genetic diversity among 66 sweet cassava (Manihot esculenta Crantz) traditional accessions collected in Maringa, Parana, Brazil, using microsatellite molecular markers. Population structure was analyzed by means of genetic distances and ...

Structural and regulatory diversity shape HLA-C protein expression levels

DEFF Research Database (Denmark)

Kaur, Gurman; Gras, Stephanie; Mobbs, Jesse I

2017-01-01

expression of HLA-C allomorphs at the cell surface by influencing the structure of the peptide-binding cleft and the diversity of peptides bound by the HLA-C molecules. Together with a phylogenetic analysis, these results highlight the diversity and long-term balancing selection of regulatory factors...

From tiny microalgae to huge biorefineries

OpenAIRE

Gouveia, L.

2014-01-01

Microalgae are an emerging research field due to their high potential as a source of several biofuels in addition to the fact that they have a high-nutritional value and contain compounds that have health benefits. They are also highly used for water stream bioremediation and carbon dioxide mitigation. Therefore, the tiny microalgae could lead to a huge source of compounds and products, giving a good example of a real biorefinery approach. This work shows and presents examples of experimental...

A case of huge neurofibroma expanding extra- and intracranially through the enlarged jugular foramen

International Nuclear Information System (INIS)

Hanakita, Junya; Imataka, Kiyoharu; Handa, Hajime

1984-01-01

The surgical approach to the jugular foramen has been considered to be very difficult and troublesome, because of the location in which important structures, such as the internal jugular vein, internal carotid artery and lower cranial nerves, converge in the narrow deep space. A case of huge neurofibroma, which extended from the tentorium cerebelli through the dilated jugular foramen to the level of the vertebral body of C 3 was presented. A 12-year-old girl was admitted with complaints of visual disturbance and palsy of the V-XII cranial nerves of the left side. Plain skull film showed prominent widening of the cranial sutures and enlargement of the sella turcica. Horizontal CT scan with contrast showed symmetrical ventricular dilatation and a heterogeneously enhanced mass, which was situated mainly in the left CP angle. Coronal CT scan with contrast revealed a huge mass and enlarged jugular foramen, through which the tumor extended to the level of the vertebral body of C 3 . Occlusion of the sigmoid sinus and the internal jugular vein of the left side was noticed in the vertebral angiography. Two-stage approach, the first one for removal of the intracranial tumor and the second one for extracranial tumor, was performed for its huge tumor. Several authors have reported excellent surgical approaches for the tumors situated in the jugular foramen. By our approach, modifying Gardner's original one, a wide operative field was obtained to remove the tumor around the jugular foramen with success. Our approach for the jugular foramen was described with illustrations. (author)

Black hole firewalls require huge energy of measurement

Science.gov (United States)

Hotta, Masahiro; Matsumoto, Jiro; Funo, Ken

2014-06-01

The unitary moving mirror model is one of the best quantum systems for checking the reasoning of the original firewall paradox of Almheiri et al. [J. High Energy Phys. 02 (2013) 062] in quantum black holes. Though the late-time part of radiations emitted from the mirror is fully entangled with the early part, no firewall exists with a deadly, huge average energy flux in this model. This is because the high-energy entanglement structure of the discretized systems in almost maximally entangled states is modified so as to yield the correct description of low-energy effective field theory. Furthermore, the strong subadditivity paradox of firewalls is resolved using nonlocality of general one-particle states and zero-point fluctuation entanglement. Due to the Reeh-Schlieder theorem in quantum field theory, another firewall paradox is inevitably raised with quantum remote measurements in the model. We resolve this paradox from the viewpoint of the energy cost of measurements. No firewall appears, as long as the energy for the measurement is much smaller than the ultraviolet cutoff scale.

Pollen diversity, viability and floral structure of some Musa genotypes

African Journals Online (AJOL)

Pollen diversity, viability and floral structure of some Musa genotypes. ... This experiment was designed to study the floral structure, pollen morphology and the potential pollen viability of five Musa genotypes obtained ... HOW TO USE AJOL.

The Evolutionary Basis of Naturally Diverse Rice Leaves Anatomy.

Directory of Open Access Journals (Sweden)

Jolly Chatterjee

Full Text Available Rice contains genetically and ecologically diverse wild and cultivated species that show a wide variation in plant and leaf architecture. A systematic characterization of leaf anatomy is essential in understanding the dynamics behind such diversity. Therefore, leaf anatomies of 24 Oryza species spanning 11 genetically diverse rice genomes were studied in both lateral and longitudinal directions and possible evolutionary trends were examined. A significant inter-species variation in mesophyll cells, bundle sheath cells, and vein structure was observed, suggesting precise genetic control over these major rice leaf anatomical traits. Cellular dimensions, measured along three growth axes, were further combined proportionately to construct three-dimensional (3D leaf anatomy models to compare the relative size and orientation of the major cell types present in a fully expanded leaf. A reconstruction of the ancestral leaf state revealed that the following are the major characteristics of recently evolved rice species: fewer veins, larger and laterally elongated mesophyll cells, with an increase in total mesophyll area and in bundle sheath cell number. A huge diversity in leaf anatomy within wild and domesticated rice species has been portrayed in this study, on an evolutionary context, predicting a two-pronged evolutionary pathway leading to the 'sativa leaf type' that we see today in domesticated species.

Self-organization in a diversity induced thermodynamics.

Science.gov (United States)

Scirè, Alessandro; Annovazzi-Lodi, Valerio

2017-01-01

In this work we show how global self-organized patterns can come out of a disordered ensemble of point oscillators, as a result of a deterministic, and not of a random, cooperative process. The resulting system dynamics has many characteristics of classical thermodynamics. To this end, a modified Kuramoto model is introduced, by including Euclidean degrees of freedom and particle polarity. The standard deviation of the frequency distribution is the disorder parameter, diversity, acting as temperature, which is both a source of motion and of disorder. For zero and low diversity, robust static phase-synchronized patterns (crystals) appear, and the problem reverts to a generic dissipative many-body problem. From small to moderate diversity crystals display vibrations followed by structure disintegration in a competition of smaller dynamic patterns, internally synchronized, each of which is capable to manage its internal diversity. In this process a huge variety of self-organized dynamic shapes is formed. Such patterns can be seen again as (more complex) oscillators, where the same description can be applied in turn, renormalizing the problem to a bigger scale, opening the possibility of pattern evolution. The interaction functions are kept local because our idea is to build a system able to produce global patterns when its constituents only interact at the bond scale. By further increasing the oscillator diversity, the dynamics becomes erratic, dynamic patterns show short lifetime, and finally disappear for high diversity. Results are neither qualitatively dependent on the specific choice of the interaction functions nor on the shape of the probability function assumed for the frequencies. The system shows a phase transition and a critical behaviour for a specific value of diversity.

Different Children, Equal Citizens and a Diverse Team of Teachers ...

African Journals Online (AJOL)

Different Children, Equal Citizens and a Diverse Team of Teachers: A Safe Space for ... articulated in order to stimulate the development of an authentic worldview of pupils ... The collaboration with Cornelia Roux made me aware of the huge ...

Diversity and population structure of red rice germplasm in Bangladesh.

Science.gov (United States)

Islam, M Z; Khalequzzaman, M; Prince, M F R K; Siddique, M A; Rashid, E S M H; Ahmed, M S U; Pittendrigh, B R; Ali, M P

2018-01-01

While the functionality and healthy food value of red rice have increased its popularity, such that market demand for it is expected to rise, most strains suffer from low grain yield. To perform diversity and population structure analyses of red rice germplasm, therefore, becomes essential for improving yields for commercial production. In this study, fifty red rice germplasm from the Bangladesh Rice Research Institute (BRRI) genebank were characterized both morphologically and genetically using fifty simple sequence repeat (SSR) markers. Overall, 162 alleles were detected by the markers with the detected allele number varying from two to seven. Additionally, 22 unique alleles were identified for use as a germplasm diagnostic tool. The highest and lowest polymorphic information content (PIC) indices were 0.75 and 0.04 found in markers RM282 and RM304, respectively, and genetic diversity was moderate, varying from 0.05 to 0.78 (average: 0.35). While phylogenetic cluster analysis of the fifteen distance-based agro-morphological traits divided the germplasm into five clusters (I, II, III, IV and V), a similar SSR analysis yielded only three major groups (I, II, and III), and a model-based population structure analysis yielded four (A, B, C and D). Both principal component and neighbors joining tree analysis from the population structure method showed the tested germplasm as highly diverse in structure. Moreover, an analysis of molecular variance (AMOVA), as well as a pairwise FST analysis, both indicated significant differentiation (ranging from 0.108 to 0.207) among all pairs of populations, suggesting that all four population structure groups differed significantly. Populations A and D were the most differentiated from each other by FST. Findings from this study suggest that the diverse germplasm and polymorphic trait-linked SSR markers of red rice are suitable for the detection of economically desirable trait loci/genes for use in future molecular breeding programs.

Natural Product Biosynthetic Diversity and Comparative Genomics of the Cyanobacteria.

Science.gov (United States)

Dittmann, Elke; Gugger, Muriel; Sivonen, Kaarina; Fewer, David P

2015-10-01

Cyanobacteria are an ancient lineage of slow-growing photosynthetic bacteria and a prolific source of natural products with intricate chemical structures and potent biological activities. The bulk of these natural products are known from just a handful of genera. Recent efforts have elucidated the mechanisms underpinning the biosynthesis of a diverse array of natural products from cyanobacteria. Many of the biosynthetic mechanisms are unique to cyanobacteria or rarely described from other organisms. Advances in genome sequence technology have precipitated a deluge of genome sequences for cyanobacteria. This makes it possible to link known natural products to biosynthetic gene clusters but also accelerates the discovery of new natural products through genome mining. These studies demonstrate that cyanobacteria encode a huge variety of cryptic gene clusters for the production of natural products, and the known chemical diversity is likely to be just a fraction of the true biosynthetic capabilities of this fascinating and ancient group of organisms. Copyright © 2015. Published by Elsevier Ltd.

On the sea-covering effect of a huge floating structure on the surrounding water; Choogata futai shuhen no kaisui ni taisuru kaimen shahei no eikyo ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Fujino, M; Kagemoto, H; Hamada, T [The University of Tokyo, Tokyo (Japan)

1997-12-31

The numerical analysis program based on the difference method for dynamics of sea water with sea-surface displacement, flow rate, salt content and temperature as the parameters is modified to more accurately assess the effects of a huge marine structure on surrounding environment by adding the effects of insolation and boundary conditions of the sea-covering effects of the floating structure. The numerical simulation was done for summer and winter seasons, not in a sea area but using a rectangular bay with the floating structure at the center. A new flow evolves around the floating structure, due to the sea-covering effect. The flow patterns in summer and winter are clearly different, due to difference in insolation. The predicted flow is also sensitive whether stratification is considered or not, by which is meant that it is important what stratification effect is taken into account. Daily insolation changes are accompanied by vertical distribution of water temperature and its temporal change. These effects are also observed under the floating structure which shields insolation. 10 refs., 17 figs., 4 tabs.

On the sea-covering effect of a huge floating structure on the surrounding water; Choogata futai shuhen no kaisui ni taisuru kaimen shahei no eikyo ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Fujino, M.; Kagemoto, H.; Hamada, T. [The University of Tokyo, Tokyo (Japan)

1996-12-31

The numerical analysis program based on the difference method for dynamics of sea water with sea-surface displacement, flow rate, salt content and temperature as the parameters is modified to more accurately assess the effects of a huge marine structure on surrounding environment by adding the effects of insolation and boundary conditions of the sea-covering effects of the floating structure. The numerical simulation was done for summer and winter seasons, not in a sea area but using a rectangular bay with the floating structure at the center. A new flow evolves around the floating structure, due to the sea-covering effect. The flow patterns in summer and winter are clearly different, due to difference in insolation. The predicted flow is also sensitive whether stratification is considered or not, by which is meant that it is important what stratification effect is taken into account. Daily insolation changes are accompanied by vertical distribution of water temperature and its temporal change. These effects are also observed under the floating structure which shields insolation. 10 refs., 17 figs., 4 tabs.

Considering Future Potential Regarding Structural Diversity in Selection of Forest Reserves.

Directory of Open Access Journals (Sweden)

Johanna Lundström

Full Text Available A rich structural diversity in forests promotes biodiversity. Forests are dynamic and therefore it is crucial to consider future structural potential when selecting reserves, to make robust conservation decisions. We analyzed forests in boreal Sweden based on 17,599 National Forest Inventory (NFI plots with the main aim to understand how effectiveness of reserves depends on the time dimension in the selection process, specifically by considering future structural diversity. In the study both the economic value and future values of 15 structural variables were simulated during a 100 year period. To get a net present structural value (NPSV, a single value covering both current and future values, we used four discounting alternatives: (1 only considering present values, (2 giving equal importance to values in each of the 100 years within the planning horizon, (3 applying an annual discount rate considering the risk that values could be lost, and (4 only considering the values in year 100. The four alternatives were evaluated in a reserve selection model under budget-constrained and area-constrained selections. When selecting young forests higher structural richness could be reached at a quarter of the cost over almost twice the area in a budget-constrained selection compared to an area-constrained selection. Our results point to the importance of considering future structural diversity in the selection of forest reserves and not as is done currently to base the selection on existing values. Targeting future values increases structural diversity and implies a relatively lower cost. Further, our results show that a re-orientation from old to young forests would imply savings while offering a more extensive reserve network with high structural qualities in the future. However, caution must be raised against a drastic reorientation of the current old-forest strategy since remnants of ancient forests will need to be prioritized due to their role for

Opposing Responses of Bird Functional Diversity to Vegetation Structural Diversity in Wet and Dry Forest.

Directory of Open Access Journals (Sweden)

Holly Sitters

Full Text Available Disturbance regimes are changing worldwide, and the consequences for ecosystem function and resilience are largely unknown. Functional diversity (FD provides a surrogate measure of ecosystem function by capturing the range, abundance and distribution of trait values in a community. Enhanced understanding of the responses of FD to measures of vegetation structure at landscape scales is needed to guide conservation management. To address this knowledge gap, we used a whole-of-landscape sampling approach to examine relationships between bird FD, vegetation diversity and time since fire. We surveyed birds and measured vegetation at 36 landscape sampling units in dry and wet forest in southeast Australia during 2010 and 2011. Four uncorrelated indices of bird FD (richness, evenness, divergence and dispersion were derived from six bird traits, and we investigated responses of these indices and species richness to both vertical and horizontal vegetation diversity using linear mixed models. We also considered the extent to which the mean and diversity of time since fire were related to vegetation diversity. Results showed opposing responses of FD to vegetation diversity in dry and wet forest. In dry forest, where fire is frequent, species richness and two FD indices (richness and dispersion were positively related to vertical vegetation diversity, consistent with theory relating to environmental variation and coexistence. However, in wet forest subject to infrequent fire, the same three response variables were negatively associated with vertical diversity. We suggest that competitive dominance by species results in lower FD as vegetation diversity increases in wet forest. The responses of functional evenness were opposite to those of species richness, functional richness and dispersion in both forest types, highlighting the value of examining multiple FD metrics at management-relevant scales. The mean and diversity of time since fire were uncorrelated

Opposing Responses of Bird Functional Diversity to Vegetation Structural Diversity in Wet and Dry Forest.

Science.gov (United States)

Sitters, Holly; York, Alan; Swan, Matthew; Christie, Fiona; Di Stefano, Julian

2016-01-01

Disturbance regimes are changing worldwide, and the consequences for ecosystem function and resilience are largely unknown. Functional diversity (FD) provides a surrogate measure of ecosystem function by capturing the range, abundance and distribution of trait values in a community. Enhanced understanding of the responses of FD to measures of vegetation structure at landscape scales is needed to guide conservation management. To address this knowledge gap, we used a whole-of-landscape sampling approach to examine relationships between bird FD, vegetation diversity and time since fire. We surveyed birds and measured vegetation at 36 landscape sampling units in dry and wet forest in southeast Australia during 2010 and 2011. Four uncorrelated indices of bird FD (richness, evenness, divergence and dispersion) were derived from six bird traits, and we investigated responses of these indices and species richness to both vertical and horizontal vegetation diversity using linear mixed models. We also considered the extent to which the mean and diversity of time since fire were related to vegetation diversity. Results showed opposing responses of FD to vegetation diversity in dry and wet forest. In dry forest, where fire is frequent, species richness and two FD indices (richness and dispersion) were positively related to vertical vegetation diversity, consistent with theory relating to environmental variation and coexistence. However, in wet forest subject to infrequent fire, the same three response variables were negatively associated with vertical diversity. We suggest that competitive dominance by species results in lower FD as vegetation diversity increases in wet forest. The responses of functional evenness were opposite to those of species richness, functional richness and dispersion in both forest types, highlighting the value of examining multiple FD metrics at management-relevant scales. The mean and diversity of time since fire were uncorrelated with vegetation

The genetic diversity and population structure of common bean ...

African Journals Online (AJOL)

SAM

2014-07-16

Jul 16, 2014 ... polymorphic molecular markers for use in hybridization and variety development. Genomic ... The model-based cluster analysis of SSR diversity in the ...... clusters of individuals using the software STRUCTURE: A simulation.

Analysis of genetic diversity and population structure in upland ...

Indian Academy of Sciences (India)

Mulugeta Seyoum

2018-06-09

Jun 9, 2018 ... diversity and population structure at DNA level, 302 elite upland cotton germplasm accessions ...... conservation of cotton germplasm in China (English abstract). ... and Alishah O. 2011 Inter simple sequence repeats (ISSR).

Structural Diversity and Close Interracial Relationships in College

Science.gov (United States)

Bowman, Nicholas A.

2012-01-01

Recent legal and political actions have challenged the use of race-conscious college admissions policies. Earlier research offers mixed evidence about the link between an institution's racial/ethnic composition (i.e., structural diversity) and the formation of close interracial relationships, so the present study examines this topic directly for…

Genetic diversity, population structure and marker trait associations ...

Indian Academy of Sciences (India)

Supplementary data: Genetic diversity, population structure and marker trait associations for seed quality traits in cotton (Gossypium hirsutum). Ashok Badigannavar and Gerald O. Myers. J. Genet. 94, 87–94. Table 1. List of cotton germplasm lines used in this study. Germplasm no. Cultivar. Region. Germplasm no. Cultivar.

Gender Diversity in Top Management and Financial Performance. The Role of Organizational Structure

DEFF Research Database (Denmark)

Opstrup, Niels; Villadsen, Anders Ryom

and financial performance of public organizations. Theory suggests that management diversity can be a positive asset for organizations. It may allow for the use of more diverse knowledge and human skill sets. In this paper it is suggested that organizations, however, may only be able to leverage...... these advantages if they have a supporting management structure. In a longitudinal study of top management teams in Danish municipalities, the study finds top management team gender diversity to be associated with higher financial performance but only in municipalities with a management structure that supports...

"Presumed fair: Ironic effects of organizational diversity structures": Correction to Kaiser et al. (2013).

Science.gov (United States)

2016-06-01

Reports an error in "Presumed fair: Ironic effects of organizational diversity structures" by Cheryl R. Kaiser, Brenda Major, Ines Jurcevic, Tessa L. Dover, Laura M. Brady and Jenessa R. Shapiro (Journal of Personality and Social Psychology, 2013[Mar], Vol 104[3], 504-519). In the article, a raw data merging error in one racial discrimination claim condition from Experiment 6 inadvertently resulted in data analyses on an inaccurate data set. When the error was discovered by the authors and corrected, all analyses reported in Experiment 6 for claim validity, seriousness of the claim, and support for the claimant were inaccurate and none were statistically significant. The conclusions should be altered to indicate that participants with management experience who reflected on their own workplace diversity policies did not show the predicted effects. The literature review, remaining five studies, and remaining conclusions in the article are unaffected by this error. Experiment 6 should also report that 26.4% (not 26.4.7%) of participants had a graduate degree and eight participants (not 8%) did not provide educational data. Experiment 5 should have referred to the claim validity measure as a six-item measure ( .92) rather than a five-item measure; analyses on claim validity are accurate in text. Table 2's note should have said standard errors, not standard deviations. (The following abstract of the original article appeared in record 2012-31077-001.) This research tests the hypothesis that the presence (vs. absence) of organizational diversity structures causes high-status group members (Whites, men) to perceive organizations with diversity structures as procedurally fairer environments for underrepresented groups (racial minorities, women), even when it is clear that underrepresented groups have been unfairly disadvantaged within these organizations. Furthermore, this illusory sense of fairness derived from the mere presence of diversity structures causes high

Relationship between diversity and the vertical structure of the upper ocean

Science.gov (United States)

Longhurst, Alan R.

1985-12-01

The sources of diversity in the plankton ecosystem of the upper 250 m in the eastern tropical Pacific Ocean are explored in the data from LHPR plankton profiles. Though there is good evidence for resource partitioning among feeding guilds of congeners, and for specialization in predation—both known to create diversity in simple aquatic ecosystems—the existence of a stable vertical structure, including a thermocline, may be one of the more important causes of variation in regional plankton diversity in the euphotic zone.

Plasmodium vivax Diversity and Population Structure across Four Continents.

Science.gov (United States)

Koepfli, Cristian; Rodrigues, Priscila T; Antao, Tiago; Orjuela-Sánchez, Pamela; Van den Eede, Peter; Gamboa, Dionicia; van Hong, Nguyen; Bendezu, Jorge; Erhart, Annette; Barnadas, Céline; Ratsimbasoa, Arsène; Menard, Didier; Severini, Carlo; Menegon, Michela; Nour, Bakri Y M; Karunaweera, Nadira; Mueller, Ivo; Ferreira, Marcelo U; Felger, Ingrid

2015-01-01

Plasmodium vivax is the geographically most widespread human malaria parasite. To analyze patterns of microsatellite diversity and population structure across countries of different transmission intensity, genotyping data from 11 microsatellite markers was either generated or compiled from 841 isolates from four continents collected in 1999-2008. Diversity was highest in South-East Asia (mean allelic richness 10.0-12.8), intermediate in the South Pacific (8.1-9.9) Madagascar and Sudan (7.9-8.4), and lowest in South America and Central Asia (5.5-7.2). A reduced panel of only 3 markers was sufficient to identify approx. 90% of all haplotypes in South Pacific, African and SE-Asian populations, but only 60-80% in Latin American populations, suggesting that typing of 2-6 markers, depending on the level of endemicity, is sufficient for epidemiological studies. Clustering analysis showed distinct clusters in Peru and Brazil, but little sub-structuring was observed within Africa, SE-Asia or the South Pacific. Isolates from Uzbekistan were exceptional, as a near-clonal parasite population was observed that was clearly separated from all other populations (FST>0.2). Outside Central Asia FST values were highest (0.11-0.16) between South American and all other populations, and lowest (0.04-0.07) between populations from South-East Asia and the South Pacific. These comparisons between P. vivax populations from four continents indicated that not only transmission intensity, but also geographical isolation affect diversity and population structure. However, the high effective population size results in slow changes of these parameters. This persistency must be taken into account when assessing the impact of control programs on the genetic structure of parasite populations.

Diversity and population structure of red rice germplasm in Bangladesh.

Directory of Open Access Journals (Sweden)

M Z Islam

Full Text Available While the functionality and healthy food value of red rice have increased its popularity, such that market demand for it is expected to rise, most strains suffer from low grain yield. To perform diversity and population structure analyses of red rice germplasm, therefore, becomes essential for improving yields for commercial production. In this study, fifty red rice germplasm from the Bangladesh Rice Research Institute (BRRI genebank were characterized both morphologically and genetically using fifty simple sequence repeat (SSR markers. Overall, 162 alleles were detected by the markers with the detected allele number varying from two to seven. Additionally, 22 unique alleles were identified for use as a germplasm diagnostic tool. The highest and lowest polymorphic information content (PIC indices were 0.75 and 0.04 found in markers RM282 and RM304, respectively, and genetic diversity was moderate, varying from 0.05 to 0.78 (average: 0.35. While phylogenetic cluster analysis of the fifteen distance-based agro-morphological traits divided the germplasm into five clusters (I, II, III, IV and V, a similar SSR analysis yielded only three major groups (I, II, and III, and a model-based population structure analysis yielded four (A, B, C and D. Both principal component and neighbors joining tree analysis from the population structure method showed the tested germplasm as highly diverse in structure. Moreover, an analysis of molecular variance (AMOVA, as well as a pairwise FST analysis, both indicated significant differentiation (ranging from 0.108 to 0.207 among all pairs of populations, suggesting that all four population structure groups differed significantly. Populations A and D were the most differentiated from each other by FST. Findings from this study suggest that the diverse germplasm and polymorphic trait-linked SSR markers of red rice are suitable for the detection of economically desirable trait loci/genes for use in future molecular

Microbial mat ecosystems: Structure types, functional diversity, and biotechnological application

Directory of Open Access Journals (Sweden)

Cristina M. Prieto-Barajas

2018-01-01

Full Text Available Microbial mats are horizontally stratified microbial communities, exhibiting a structure defined by physiochemical gradients, which models microbial diversity, physiological activities, and their dynamics as a whole system. These ecosystems are commonly associated with aquatic habitats, including hot springs, hypersaline ponds, and intertidal coastal zones and oligotrophic environments, all of them harbour phototrophic mats and other environments such as acidic hot springs or acid mine drainage harbour non-photosynthetic mats. This review analyses the complex structure, diversity, and interactions between the microorganisms that form the framework of different types of microbial mats located around the globe. Furthermore, the many tools that allow studying microbial mats in depth and their potential biotechnological applications are discussed.

Huge mucinous cystadenoma of the pancreas mistaken for a ...

African Journals Online (AJOL)

Cystic tumors of the pancreas are rare and can be confused with pseudocysts.We present a 50 year old woman with a huge mucinous cystadenoma of the pancreas initially diagnosed and managed with a cystojejunostomy and cyst wall biopsy. She required another laparotomy and tumor excision after histological ...

On the estimation method of hydrodynamic forces acting on a huge floating structure; Choogata futai ni hataraku haryoku ryutairyoku no suiteiho ni kansuru kenkyu

Energy Technology Data Exchange (ETDEWEB)

Kagemoto, H.; Fujino, M.; Zhu, T. [The University of Tokyo, Tokyo (Japan)

1996-12-31

A floating structure such as an international airport is anticipated to have a length of about 5,000 m and a width of about 1,000 m. A singular point method may be used as a method to estimate force that such a floating body is subjected to from waves. In order to derive a solution with practically sufficient accuracy, 1250 elements are required in the length direction and 250 elements in the width direction, or a total of 312,500 elements. Calculating this number of elements should use finally a linear equation system handling complex coefficients comprising 312,500 elements, which would require a huge amount of calculation time. This paper proposes a method to derive solution on wave forces acting on a super-large floating structure or fluid force coefficients such as added mass coefficients and decay coefficients at a practically workable calculation amount and still without degrading the accuracy. The structure was assumed to be a box-shaped structure. Strengths of the singular points to be distributed on each element were assumed to be almost constant except for edges in lateral, oblique and longitudinal waves. Under this assumption, the interior of the floating structure excepting its edges was represented by several large elements to have reduced the number of elements. A calculation method proposed based on this conception was verified of its effectiveness. 2 refs., 25 figs., 3 tabs.

Genetic diversity and structure of elite cotton germplasm (Gossypium hirsutum L.) using genome-wide SNP data.

Science.gov (United States)

Ai, XianTao; Liang, YaJun; Wang, JunDuo; Zheng, JuYun; Gong, ZhaoLong; Guo, JiangPing; Li, XueYuan; Qu, YanYing

2017-10-01

Cotton (Gossypium spp.) is the most important natural textile fiber crop, and Gossypium hirsutum L. is responsible for 90% of the annual cotton crop in the world. Information on cotton genetic diversity and population structure is essential for new breeding lines. In this study, we analyzed population structure and genetic diversity of 288 elite Gossypium hirsutum cultivar accessions collected from around the world, and especially from China, using genome-wide single nucleotide polymorphisms (SNP) markers. The average polymorphsim information content (PIC) was 0.25, indicating a relatively low degree of genetic diversity. Population structure analysis revealed extensive admixture and identified three subgroups. Phylogenetic analysis supported the subgroups identified by STRUCTURE. The results from both population structure and phylogenetic analysis were, for the most part, in agreement with pedigree information. Analysis of molecular variance revealed a larger amount of variation was due to diversity within the groups. Establishment of genetic diversity and population structure from this study could be useful for genetic and genomic analysis and systematic utilization of the standing genetic variation in upland cotton.

Aggressive angiomyxoma presenting with huge abdominal lump: A case report

Science.gov (United States)

Kumar, Sanjeev; Agrawal, Nikhil; Khanna, Rahul; Khanna, AK

2008-01-01

Agressive angiomyxoma is a rare mesenchymal neoplasm. It mainly presents in females. We here present a case of angiomyxoma presenting as huge abdominal lump along with gluteal swelling. Case note is described along with brief review of literature. PMID:18755035

Umbilicoplasty in children with huge umbilical hernia | Komlatsè ...

African Journals Online (AJOL)

With a mean follow-up of 10 months, we had 10 excellent results and two fair results according to our criteria. Conclusion: Our two lateral fl aps umbilicoplasty is well-adapted to HUH in children. Itis simple and assures a satisfactory anatomical and cosmetic result. Key words: Children, huge umbilical hernia, Togo, umbilical ...

Are "Diversity Management" and Monolingualism Compatible? About Learning and Using Foreign Languages in a Context of Globalisation

Science.gov (United States)

Ludi, Georges

2010-01-01

Ideologies and communication practices vary hugely in multilingual workplaces. On the one hand, many companies include Diversity Management in their corporate culture because there are theoretical and empirical reasons to believe that a company which employs a diverse workforce enhances its opportunities in a global marketplace whilst improving…

Population structure and genetic diversity of Sudanese native chickens

African Journals Online (AJOL)

The objectives of this study were to analyze genetic diversity and population structure of Sudanese native chicken breeds involved in a conservation program. Five Sudanese native chicken breeds were compared with populations studied previously, which included six purebred lines, six African populations and one ...

Pollen diversity, viability and floral structure of some Musa genotypes

African Journals Online (AJOL)

Prof. Ogunji

Pollen diversity, viability and floral structure of some Musa genotypes ... at the Faculty of Agriculture & Natural Resources Management farm, Ebonyi State University,. Abakaliki. ..... Roots, tuber, plantains and bananas in human nutrition. Rome,.

A bouquet of DNA structures: Emerging diversity

Directory of Open Access Journals (Sweden)

Mahima Kaushik

2016-03-01

Full Text Available Structural polymorphism of DNA has constantly been evolving from the time of illustration of the double helical model of DNA by Watson and Crick. A variety of non-canonical DNA structures have constantly been documented across the globe. DNA attracted worldwide attention as a carrier of genetic information. In addition to the classical Watson–Crick duplex, DNA can actually adopt diverse structures during its active participation in cellular processes like replication, transcription, recombination and repair. Structures like hairpin, cruciform, triplex, G-triplex, quadruplex, i-motif and other alternative non-canonical DNA structures have been studied at length and have also shown their in vivo occurrence. This review mainly focuses on non-canonical structures adopted by DNA oligonucleotides which have certain prerequisites for their formation in terms of sequence, its length, number and orientation of strands along with varied solution conditions. This conformational polymorphism of DNA might be the basis of different functional properties of a specific set of DNA sequences, further giving some insights for various extremely complicated biological phenomena. Many of these structures have already shown their linkages with diseases like cancer and genetic disorders, hence making them an extremely striking target for structure-specific drug designing and therapeutic applications.

A bouquet of DNA structures: Emerging diversity.

Science.gov (United States)

Kaushik, Mahima; Kaushik, Shikha; Roy, Kapil; Singh, Anju; Mahendru, Swati; Kumar, Mohan; Chaudhary, Swati; Ahmed, Saami; Kukreti, Shrikant

2016-03-01

Structural polymorphism of DNA has constantly been evolving from the time of illustration of the double helical model of DNA by Watson and Crick. A variety of non-canonical DNA structures have constantly been documented across the globe. DNA attracted worldwide attention as a carrier of genetic information. In addition to the classical Watson-Crick duplex, DNA can actually adopt diverse structures during its active participation in cellular processes like replication, transcription, recombination and repair. Structures like hairpin, cruciform, triplex, G-triplex, quadruplex, i-motif and other alternative non-canonical DNA structures have been studied at length and have also shown their in vivo occurrence. This review mainly focuses on non-canonical structures adopted by DNA oligonucleotides which have certain prerequisites for their formation in terms of sequence, its length, number and orientation of strands along with varied solution conditions. This conformational polymorphism of DNA might be the basis of different functional properties of a specific set of DNA sequences, further giving some insights for various extremely complicated biological phenomena. Many of these structures have already shown their linkages with diseases like cancer and genetic disorders, hence making them an extremely striking target for structure-specific drug designing and therapeutic applications.

Cellulose microfibril structure: inspirations from plant diversity

Science.gov (United States)

Roberts, A. W.

2018-03-01

Cellulose microfibrils are synthesized at the plasma membrane by cellulose synthase catalytic subunits that associate to form cellulose synthesis complexes. Variation in the organization of these complexes underlies the variation in cellulose microfibril structure among diverse organisms. However, little is known about how the catalytic subunits interact to form complexes with different morphologies. We are using an evolutionary approach to investigate the roles of different catalytic subunit isoforms in organisms that have rosette-type cellulose synthesis complexes.

[Species, functional, structural diversity of typical plant communities and their responses to environmental factors in Miao Archipelago, China.

Science.gov (United States)

Zheng, Li Ting; Su, Tian; Liu, Xiang Yu; Yin, Fang; Guo, Chao; Tuo, Bin; Yan, En Rong

2018-02-01

Island vegetation plays an important role in biodiversity research across the world. The study of plant diversity in island is helpful for understanding the mechanism of plant diversity maintenance under land-sea interaction. Here, four typical plant communities (Quercus acutissima community, Robinia pseudoacacia community, Pinus thunbergii community and Vitex negundo community) in Miao Archipelago were selected to examine the species, functional and structural diversities and their responses to environmental factors at the community scale by using species diversity indices, functional diversity indices, as well as structural diversity indices. The results showed that the species richness and Rao index of P. thunbergii community was higher than that of Q. acutissima community and R. pseudoacacia community, but the structural diversity was lower. The species diversity and structural diversity of V. Negundo shrub were lower than that of forest community, but the functional diversity was higher than some forest communities. The relationship between the diversity of typical plant communities in island area illustrated a significant positive correlation between species richness with Rao index and tree height diversity, however the correlation with functional evenness was significantly negative. The structural diversity and functional evenness were determined by slope with negative and positive relationships, respectively. Functional heterogeneity, functional divergence and species diversity were affected largely by soil physical and chemical properties, displaying the positive relationship with soil bulk density and soil total carbon content, and a negative relationship with soil water content. In conclusion, diversity pattern of plant community in Miao Archipelago reflected not only the characteristics in mainland vegetation but also the special nature of the sea island.

SSR-based genetic diversity and structure of garlic accessions from Brazil.

Science.gov (United States)

da Cunha, Camila Pinto; Resende, Francisco Vilela; Zucchi, Maria Imaculada; Pinheiro, José Baldin

2014-10-01

Garlic is a spice and a medicinal plant; hence, there is an increasing interest in 'developing' new varieties with different culinary properties or with high content of nutraceutical compounds. Phenotypic traits and dominant molecular markers are predominantly used to evaluate the genetic diversity of garlic clones. However, 24 SSR markers (codominant) specific for garlic are available in the literature, fostering germplasm researches. In this study, we genotyped 130 garlic accessions from Brazil and abroad using 17 polymorphic SSR markers to assess the genetic diversity and structure. This is the first attempt to evaluate a large set of accessions maintained by Brazilian institutions. A high level of redundancy was detected in the collection (50 % of the accessions represented eight haplotypes). However, non-redundant accessions presented high genetic diversity. We detected on average five alleles per locus, Shannon index of 1.2, HO of 0.5, and HE of 0.6. A core collection was set with 17 accessions, covering 100 % of the alleles with minimum redundancy. Overall FST and D values indicate a strong genetic structure within accessions. Two major groups identified by both model-based (Bayesian approach) and hierarchical clustering (UPGMA dendrogram) techniques were coherent with the classification of accessions according to maturity time (growth cycle): early-late and midseason accessions. Assessing genetic diversity and structure of garlic collections is the first step towards an efficient management and conservation of accessions in genebanks, as well as to advance future genetic studies and improvement of garlic worldwide.

Network diversity structure, closeness and innovation of South African micro-entrepreneurs

OpenAIRE

Eliada Wosu Griffin-EL

2014-01-01

This study qualitatively explores the embeddedness of the innovation process of South African microbusinesses by investigating how small local entrepreneurs in the Greater Johannesburg area utilise their social networks to source entrepreneurial value. A comparative grounded theory analysis enabled the original conceptualisation of Network Diversity Structure and formulates the central proposition that the network dimensions of diversity and closeness enable the innovation process among manuf...

Huge mucinous cystadenoma of ovary, describing a young patient: case report

Directory of Open Access Journals (Sweden)

Soheila Aminimoghaddam

2017-08-01

Conclusion: Ovarian cysts in young women who are associated with elevated levels of tumor markers and ascites require careful evaluation. Management of ovarian cysts depends on patient's age, size of the cyst, and its histopathological nature. Conservative surgery such as ovarian cystectomy or salpingo-oophorectomy is adequate in mucinous tumors of ovary. Multiple frozen sections are very important to know the malignant variation of this tumor and helps accurate patient management. Surgical expertise is required to prevent complications in huge tumors has distorted the anatomy, so gynecologic oncologist plays a prominent role in management. In this case, beside of the huge tumor and massive ascites uterine and ovaries were preserved by gynecologist oncologist and patient is well up to now.

A Huge Ovarian Dermoid Cyst: Successful Laparoscopic Total Excision

OpenAIRE

Uyanikoglu, Hacer; Dusak, Abdurrahim

2017-01-01

Giant ovarian cysts, ≥15 cm in diameter, are quite rare in women of reproductive age. Here, we present a case of ovarian cyst with unusual presentation treated by laparoscopic surgery. On histology, mass was found to be mature cystic teratoma. The diagnostic and management challenges posed by this huge ovarian cyst were discussed in the light of the literature.

A Huge Ovarian Cyst in a Middle-Aged Iranian Female

Directory of Open Access Journals (Sweden)

Mohammad Kazem Moslemi

2010-05-01

Full Text Available A 38-year-old Iranian woman was found to have a huge ovarian cystic mass. Her presenting symptom was vague abdominal pain and severe abdominal distention. She underwent laparotomy and after surgical removal, the mass was found to be mucinous cystadenoma on histology.

Diversity and structure of woody vegetation across areas with ...

African Journals Online (AJOL)

Here we investigate the differences and/or similarities of woody vegetation diversity and structure across areas with different edaphic factors (i.e. soil group) in Gonarezhou National Park, Zimbabwe. We stratified our study area into two strata based on soil group, namely siallitic soil in northern Gonarezhou and regosol soil ...

Genetic diversity, structure and differentiation in cultivate walnut (Juglans regia L.)

Science.gov (United States)

M. Aradhya; K. Woeste; D. Velasco

2012-01-01

An analysis of genetic structure and differentiation in cultivated walnut (Juglans regia) using 15 microsatellite loci revealed a considerable amount of genetic variation with a mild genetic structure indicating five genetic groups corresponding to the centers of diversity within the home range of walnut in Eurasia. Despite the narrow genetic...

Genetic Diversity and Population Structure of Cowpea (Vigna unguiculata L. Walp).

Science.gov (United States)

Xiong, Haizheng; Shi, Ainong; Mou, Beiquan; Qin, Jun; Motes, Dennis; Lu, Weiguo; Ma, Jianbing; Weng, Yuejin; Yang, Wei; Wu, Dianxing

2016-01-01

The genetic diversity of cowpea was analyzed, and the population structure was estimated in a diverse set of 768 cultivated cowpea genotypes from the USDA GRIN cowpea collection, originally collected from 56 countries. Genotyping by sequencing was used to discover single nucleotide polymorphism (SNP) in cowpea and the identified SNP alleles were used to estimate the level of genetic diversity, population structure, and phylogenetic relationships. The aim of this study was to detect the gene pool structure of cowpea and to determine its relationship between different regions and countries. Based on the model-based ancestry analysis, the phylogenetic tree, and the principal component analysis, three well-differentiated genetic populations were postulated from 768 worldwide cowpea genotypes. According to the phylogenetic analyses between each individual, region, and country, we may trace the accession from off-original, back to the two candidate original areas (West and East of Africa) to predict the migration and domestication history during the cowpea dispersal and development. To our knowledge, this is the first report of the analysis of the genetic variation and relationship between globally cultivated cowpea genotypes. The results will help curators, researchers, and breeders to understand, utilize, conserve, and manage the collection for more efficient contribution to international cowpea research.

Huge music archives on mobile devices

DEFF Research Database (Denmark)

Blume, H.; Bischl, B.; Botteck, M.

2011-01-01

The availability of huge nonvolatile storage capacities such as flash memory allows large music archives to be maintained even in mobile devices. With the increase in size, manual organization of these archives and manual search for specific music becomes very inconvenient. Automated dynamic...... organization enables an attractive new class of applications for managing ever-increasing music databases. For these types of applications, extraction of music features as well as subsequent feature processing and music classification have to be performed. However, these are computationally intensive tasks...... and difficult to tackle on mobile platforms. Against this background, we provided an overview of algorithms for music classification as well as their computation times and other hardware-related aspects, such as power consumption on various hardware architectures. For mobile platforms such as smartphones...

Butterflies show different functional and species diversity in relationship to vegetation structure and land use

NARCIS (Netherlands)

Aguirre-Gutiérrez, J.; WallisDeVries, M.F.; Marshall, L.; van't Zelfde, M.; Villalobos-Arámbula, A.R.; Boekelo, B.; Bartholomeus, H.; Franzén, M.; Biesmeijer, J.C.

2017-01-01

Aim: Biodiversity is rapidly disappearing at local and global scales also affecting the functional diversity of ecosystems. We aimed to assess whether functional diversity was correlated with species diversity and whether both were affected by similar land use and vegetation structure drivers.

Genetic structure and diversity within and among six populations of ...

African Journals Online (AJOL)

Yomi

2010-04-24

Apr 24, 2010 ... Genetic structure and diversity within and among six populations of .... Lyopholized samples were ground to a fine powder. DNA extraction ..... 22(3): 287-292. Pei YL, Zou, YP, Yin Z, Wang XQ, Zhang ZX, Hong DY (1995).

Huge Mesenteric Lymphangioma – A Rare Cause of Acute Abdomen

African Journals Online (AJOL)

Lymphangiomas are benign congenital masses which occur most commonly in head and neck of children and incidence of mesenteric lymphangiomas is very rare. We report such a case of huge mesenteric lymphangioma in a 20 year old male who presented to us with acute abdomen. Pre-operative diagnosis is difficult ...

Huge cystic craniopharyngioma. Changes of cyst density on computed tomography

Energy Technology Data Exchange (ETDEWEB)

Takamura, Seishi; Fukumura, Akinobu; Ito, Yoshihiro; Itoyama, Yoichi; Matsukado, Yasuhiko

1986-06-01

The findings of computed tomography (CT) of a huge cystic craniopharyngioma in a 57-year-old woman are described. Cyst density varied from low to high levels in a short duration. Follow-up CT scans were regarded as important to diagnose craniopharyngioma. The mechanism of increment of cyst density was discussed.

Interactive diversity promotes the evolution of cooperation in structured populations

International Nuclear Information System (INIS)

Su, Qi; Li, Aming; Zhou, Lei; Wang, Long

2016-01-01

Evolutionary games on networks traditionally assume that each individual adopts an identical strategy to interact with all its neighbors in each generation. Considering the prevalent diversity of individual interactions in the real society, here we propose the concept of interactive diversity, which allows individuals to adopt different strategies against different neighbors in each generation. We investigate the evolution of cooperation based on the edge dynamics rather than the traditional nodal dynamics in networked systems. The results show that, without invoking any other mechanisms, interactive diversity drives the frequency of cooperation to a high level for a wide range of parameters in both well-mixed and structured populations. Even in highly connected populations, cooperation still thrives. When interactive diversity and large topological heterogeneity are combined together, however, in the relaxed social dilemma, cooperation level is lower than that with just one of them, implying that the combination of many promotive factors may make a worse outcome. By an analytical approximation, we get the condition under which interactive diversity provides more advantages for cooperation than traditional evolutionary dynamics does. Numerical simulations validating the approximation are also presented. Our work provides a new line to explore the latent relation between the ubiquitous cooperation and individuals’ distinct responses in different interactions. The presented results suggest that interactive diversity should receive more attention in pursuing mechanisms fostering cooperation. (paper)

Are ‘diversity management' and monolingualism compatible? About learning and using foreign languages in a context of globalisation: Sind ,diversity management' und Einsprachigkeit kompatibel? Vom Fremdsprachenlernen und -gebrauch unter dem Einfluss der Globalisierung

OpenAIRE

Lüdi, Georges

2017-01-01

Ideologies and communication practices vary hugely in multilingual workplaces. On the one hand, many companies include Diversity Management in their corporate culture because there are theoretical and empirical reasons to believe that a company which employs a diverse workforce enhances its opportunities in a global marketplace whilst improving employee satisfaction and thus productivity. On the other hand, globally oriented companies, often the same ones, choose English preferentially as the...

ITS2 sequence-structure phylogeny reveals diverse endophytic Pseudocercospora fungi on poplars.

Science.gov (United States)

Yan, Dong-Hui; Gao, Qian; Sun, Xiaoming; Song, Xiaoyu; Li, Hongchang

2018-04-01

For matching the new fungal nomenclature to abolish pleomorphic names for a fungus, a genus Pseudocercospora s. str. was suggested to host holomorphic Pseudocercosproa fungi. But the Pseudocercosproa fungi need extra phylogenetic loci to clarify their taxonomy and diversity for their existing and coming species. Internal transcribed spacer 2 (ITS2) secondary structures have been promising in charactering species phylogeny in plants, animals and fungi. In present study, a conserved model of ITS2 secondary structures was confirmed on fungi in Pseudocercospora s. str. genus using RNAshape program. The model has a typical eukaryotic four-helix ITS2 secondary structure. But a single U base occurred in conserved motif of U-U mismatch in Helix 2, and a UG emerged in UGGU motif in Helix 3 to Pseudocercospora fungi. The phylogeny analyses based on the ITS2 sequence-secondary structures with compensatory base change characterizations are able to delimit more species for Pseudocercospora s. str. than phylogenic inferences of traditional multi-loci alignments do. The model was employed to explore the diversity of endophytic Pseudocercospora fungi in poplar trees. The analysis results also showed that endophytic Pseudocercospora fungi were diverse in species and evolved a specific lineage in poplar trees. This work suggested that ITS2 sequence-structures could become as additionally significant loci for species phylogenetic and taxonomic studies on Pseudocerospora fungi, and that Pseudocercospora endophytes could be important roles to Pseudocercospora fungi's evolution and function in ecology.

SPECIES DIVERSITY AND COMMUNITY STRUCTURE OF SUCKING LICE IN YUNNAN, CHINA

Institute of Scientific and Technical Information of China (English)

Xian-guoGuo; Ti-junQian; Li-junGuo; JingWang; Wen-geDong; LiZhang; Zhi-minMa; andWeiLi

2004-01-01

On the basis of investigating 9 counties (towns) in Yunnan Province of China, the species diversity and community structure of sucking lice on the body surface of small mammal hosts are studied in the paper. Species richness (S) is used to stand for the species diversity. The calculation of community diversity index and evenness are based on Shannon-Wiener's method. 2745 small mammals captured from the investigated sites belong to 10 families, 25 genera and 41 species in 5 orders (Rodentia, Insectivora, Scandentia, Logomorpha and Carnivora) while 18165 individuals of sucking lice collected from the body surface of the small mammal hosts are identified into 4 families, 6 genera and 22 species. The species of sucking lice are much less than the species of their hosts. Most species of small mammals have their fixed sucking lice on their body surface. One species of small mammals usually have few species of sucking lice (1 to 4 species). The close species of the hosts in the taxonomy are found to have the same or similar dominant species of sucking lice on their body surface. The results reveal that the species diversity of sucking lice on small mammals is very low with a very simple community structure. The results also imply there may be a close co-evolution relationship between the lice and the hosts.

Structure and genetic diversity of natural Brazilian pepper populations (Schinus terebinthifolius Raddi).

Science.gov (United States)

Álvares-Carvalho, S V; Duarte, J F; Santos, T C; Santos, R M; Silva-Mann, R; Carvalho, D

2016-06-17

In the face of a possible loss of genetic diversity in plants due the environmental changes, actions to ensure the genetic variability are an urgent necessity. The extraction of Brazilian pepper fruits is a cause of concern because it results in the lack of seeds in soil, hindering its distribution in space and time. It is important to address this concern and explore the species, used by riparian communities and agro-factories without considering the need for keeping the seeds for natural seed banks and for species sustainability. The objective of this study was to evaluate the structure and the genetic diversity in natural Brazilian pepper populations (Schinus terebinthifolius Raddi). Twenty-two alleles in 223 individuals were identified from eight forest remnants located in the states of Minas Gerais, Espírito Santo, and Sergipe. All populations presented loci in Hardy-Weinberg equilibrium deviation. Four populations presented six combinations of loci in linkage disequilibrium. Six exclusive alleles were detected in four populations. Analysis of molecular variance showed the absence of diversity between regions and that between the populations (GST) was 41%. Genetic diversity was structured in seven clusters (ΔK7). Brazilian pepper populations were not structured in a pattern of isolation by distance and present genetic bottleneck. The populations São Mateus, Canastra, Barbacena, and Ilha das Flores were identified as management units and may support conservation projects, ecological restoration and in implementation of management plans for Brazilian pepper in the State of Sergipe.

An analysis of the genetic diversity and genetic structure of ...

African Journals Online (AJOL)

Scientific approaches to conservation of threatened species depend on a good understanding of the genetic information of wild and artificial population. The genetic diversity and structure analysis of 10 Eucommia ulmoides population was analyzed using inter-simple sequence repeat (ISSR) markers in this paper.

61 HUGE BENIGN GRANULOSA CELL TUMOUR IN A 61 YEAR ...

African Journals Online (AJOL)

Dr. E. P. Gharoro

peritoneal cavity, huge right ovarian cyst measuring 37cm/29cm as in figure 1a, weighing 8.3 kg with a thick smooth wall without excrescences on surface. ... is released in the blood during pregnancy and is produced in other conditions such as endometriosis, fibroids and diverticulitis. It is useful in monitoring therapy.

Churn prediction on huge telecom data using hybrid firefly based classification

Directory of Open Access Journals (Sweden)

Ammar A.Q. Ahmed

2017-11-01

Full Text Available Churn prediction in telecom has become a major requirement due to the increase in the number of telecom providers. However due to the hugeness, sparsity and imbalanced nature of the data, churn prediction in telecom has always been a complex task. This paper presents a metaheuristic based churn prediction technique that performs churn prediction on huge telecom data. A hybridized form of Firefly algorithm is used as the classifier. It has been identified that the compute intensive component of the Firefly algorithm is the comparison block, where every firefly is compared with every other firefly to identify the one with the highest light intensity. This component is replaced by Simulated Annealing and the classification process is carried out. Experiments were conducted on the Orange dataset. It was observed that Firefly algorithm works best on churn data and the hybridized Firefly algorithm provides effective and faster results.

A parallel solver for huge dense linear systems

Science.gov (United States)

Badia, J. M.; Movilla, J. L.; Climente, J. I.; Castillo, M.; Marqués, M.; Mayo, R.; Quintana-Ortí, E. S.; Planelles, J.

2011-11-01

HDSS (Huge Dense Linear System Solver) is a Fortran Application Programming Interface (API) to facilitate the parallel solution of very large dense systems to scientists and engineers. The API makes use of parallelism to yield an efficient solution of the systems on a wide range of parallel platforms, from clusters of processors to massively parallel multiprocessors. It exploits out-of-core strategies to leverage the secondary memory in order to solve huge linear systems O(100.000). The API is based on the parallel linear algebra library PLAPACK, and on its Out-Of-Core (OOC) extension POOCLAPACK. Both PLAPACK and POOCLAPACK use the Message Passing Interface (MPI) as the communication layer and BLAS to perform the local matrix operations. The API provides a friendly interface to the users, hiding almost all the technical aspects related to the parallel execution of the code and the use of the secondary memory to solve the systems. In particular, the API can automatically select the best way to store and solve the systems, depending of the dimension of the system, the number of processes and the main memory of the platform. Experimental results on several parallel platforms report high performance, reaching more than 1 TFLOP with 64 cores to solve a system with more than 200 000 equations and more than 10 000 right-hand side vectors. New version program summaryProgram title: Huge Dense System Solver (HDSS) Catalogue identifier: AEHU_v1_1 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEHU_v1_1.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 87 062 No. of bytes in distributed program, including test data, etc.: 1 069 110 Distribution format: tar.gz Programming language: Fortran90, C Computer: Parallel architectures: multiprocessors, computer clusters Operating system

Structural Diversity of Self-Assembled Iridescent Arthropod Biophotonic Nanostructures

Science.gov (United States)

Saranathan, Vinod Kumar; Prum, Richard O.

2015-03-01

Many organisms, especially arthropods, produce vivid interference colors using diverse mesoscopic (100-350 nm) integumentary biophotonic nanostructures that are increasingly being investigated for technological applications. Despite a century of interest, we lack precise structural knowledge of many biophotonic nanostructures and mechanisms controlling their development, when such knowledge can open novel biomimetic routes to facilely self-assemble tunable, multi-functional materials. Here, we use synchrotron small angle X-ray scattering and electron microscopy to characterize the photonic nanostructure of 140 iridescent integumentary scales and setae from 127 species of terrestrial arthropods in 85 genera from 5 orders. We report a rich nanostructural diversity, including triply-periodic bicontinuous networks, close-packed spheres, inverse columnar, perforated lamellar, and disordered sponge-like morphologies, commonly observed as stable phases of amphiphilic surfactants, block copolymer, and lyotropic lipid-water systems. Diverse arthropod lineages appear to have independently evolved to utilize the self-assembly of infolding bilayer membranes to develop biophotonic nanostructures that span the phase-space of amphiphilic morphologies, but at optical length scales.

K-shuff: A Novel Algorithm for Characterizing Structural and Compositional Diversity in Gene Libraries.

Science.gov (United States)

Jangid, Kamlesh; Kao, Ming-Hung; Lahamge, Aishwarya; Williams, Mark A; Rathbun, Stephen L; Whitman, William B

2016-01-01

K-shuff is a new algorithm for comparing the similarity of gene sequence libraries, providing measures of the structural and compositional diversity as well as the significance of the differences between these measures. Inspired by Ripley's K-function for spatial point pattern analysis, the Intra K-function or IKF measures the structural diversity, including both the richness and overall similarity of the sequences, within a library. The Cross K-function or CKF measures the compositional diversity between gene libraries, reflecting both the number of OTUs shared as well as the overall similarity in OTUs. A Monte Carlo testing procedure then enables statistical evaluation of both the structural and compositional diversity between gene libraries. For 16S rRNA gene libraries from complex bacterial communities such as those found in seawater, salt marsh sediments, and soils, K-shuff yields reproducible estimates of structural and compositional diversity with libraries greater than 50 sequences. Similarly, for pyrosequencing libraries generated from a glacial retreat chronosequence and Illumina® libraries generated from US homes, K-shuff required >300 and 100 sequences per sample, respectively. Power analyses demonstrated that K-shuff is sensitive to small differences in Sanger or Illumina® libraries. This extra sensitivity of K-shuff enabled examination of compositional differences at much deeper taxonomic levels, such as within abundant OTUs. This is especially useful when comparing communities that are compositionally very similar but functionally different. K-shuff will therefore prove beneficial for conventional microbiome analysis as well as specific hypothesis testing.

Molecular diversity and tools for deciphering the methanogen community structure and diversity in freshwater sediments.

Science.gov (United States)

Chaudhary, Prem Prashant; Brablcová, Lenka; Buriánková, Iva; Rulík, Martin

2013-09-01

Methanogenic archaeal communities existing in freshwater sediments are responsible for approximately 50 % of the total global emission of methane. This process contributes significantly to global warming and, hence, necessitates interventional control measures to limit its emission. Unfortunately, the diversity and functional interactions of methanogenic populations occurring in these habitats are yet to be fully characterized. Considering several disadvantages of conventional culture-based methodologies, in recent years, impetus is given to molecular biology approaches to determine the community structure of freshwater sedimentary methanogenic archaea. 16S rRNA and methyl coenzyme M reductase (mcrA) gene-based cloning techniques are the first choice for this purpose. In addition, electrophoresis-based (denaturing gradient gel electrophoresis, temperature gradient gel electrophoresis, and terminal restriction fragment length polymorphism) and quantitative real-time polymerase chain reaction techniques have also found extensive applications. These techniques are highly sensitive, rapid, and reliable as compared to traditional culture-dependent approaches. Molecular diversity studies revealed the dominance of the orders Methanomicrobiales and Methanosarcinales of methanogens in freshwater sediments. The present review discusses in detail the status of the diversity of methanogens and the molecular approaches applied in this area of research.

The relationship between species diversity and genetic structure in the rare Picea chihuahuana tree species community, Mexico.

Science.gov (United States)

Simental-Rodríguez, Sergio Leonel; Quiñones-Pérez, Carmen Zulema; Moya, Daniel; Hernández-Tecles, Enrique; López-Sánchez, Carlos Antonio; Wehenkel, Christian

2014-01-01

Species diversity and genetic diversity, the most basic elements of biodiversity, have long been treated as separate topics, although populations evolve within a community context. Recent studies on community genetics and ecology have suggested that genetic diversity is not completely independent of species diversity. The Mexican Picea chihuahuana Martínez is an endemic species listed as "Endangered" on the Red List. Forty populations of Chihuahua spruce have been identified. This species is often associated with tree species of eight genera in gallery forests. This rare Picea chihuahuana tree community covers an area no more than 300 ha and has been subject of several studies involving different topics such as ecology, genetic structure and climate change. The overall aim of these studies was to obtain a dataset for developing management tools to help decision makers implement preservation and conservation strategies. However, this unique forest tree community may also represent an excellent subject for helping us to understand the interplay between ecological and evolutionary processes in determining community structure and dynamics. The AFLP technique and species composition data were used together to test the hypothesis that species diversity is related to the adaptive genetic structure of some dominant tree species (Picea chihuahuana, Pinus strobiformis, Pseudotsuga menziesii and Populus tremuloides) of the Picea chihuahuana tree community at fourteen locations. The Hill numbers were used as a diversity measure. The results revealed a significant correlation between tree species diversity and genetic structure in Populus tremuloides. Because the relationship between the two levels of diversity was found to be positive for the putative adaptive AFLP detected, genetic and species structures of the tree community were possibly simultaneously adapted to a combination of ecological or environmental factors. The present findings indicate that interactions between

Situating and Constructing Diversity in Semi-Structured Interviews

Directory of Open Access Journals (Sweden)

Michele J. McIntosh

2015-08-01

Full Text Available Although semi-structured interviews (SSIs are used extensively in research, scant attention is given to their diversity, underlying assumptions, construction, and broad applications to qualitative and mixed-method research. In this three-part article, we discuss the following: (a how the SSI is situated historically including its evolution and diversification, (b the principles of constructing SSIs, and (c how SSIs are utilized as a stand-alone research method, and as strategy within a mixed-method design.

Genetic diversity, population structure, and traditional culture of Camellia reticulata.

Science.gov (United States)

Xin, Tong; Huang, Weijuan; De Riek, Jan; Zhang, Shuang; Ahmed, Selena; Van Huylenbroeck, Johan; Long, Chunlin

2017-11-01

Camellia reticulata is an arbor tree that has been cultivated in southwestern China by various sociolinguistic groups for esthetic purposes as well as to derive an edible seed oil. This study examined the influence of management, socio-economic factors, and religion on the genetic diversity patterns of Camellia reticulata utilizing a combination of ethnobotanical and molecular genetic approaches. Semi-structured interviews and key informant interviews were carried out with local communities in China's Yunnan Province. We collected plant material ( n  = 190 individuals) from five populations at study sites using single-dose AFLP markers in order to access the genetic diversity within and between populations. A total of 387 DNA fragments were produced by four AFLP primer sets. All DNA fragments were found to be polymorphic (100%). A relatively high level of genetic diversity was revealed in C. reticulata samples at both the species ( H sp  = 0.3397, I sp  = 0.5236) and population (percentage of polymorphic loci = 85.63%, H pop  = 0.2937, I pop  = 0.4421) levels. Findings further revealed a relatively high degree of genetic diversity within C. reticulata populations (Analysis of Molecular Variance = 96.31%). The higher genetic diversity within populations than among populations of C. reticulata from different geographies is likely due to the cultural and social influences associated with its long cultivation history for esthetic and culinary purposes by diverse sociolinguistic groups. This study highlights the influence of human management, socio-economic factors, and other cultural variables on the genetic and morphological diversity of C. reticulata at a regional level. Findings emphasize the important role of traditional culture on the conservation and utilization of plant genetic diversity.

Genetic diversity and population structure of Sitodiplosis mosellana in Northern China.

Directory of Open Access Journals (Sweden)

Yun Duan

Full Text Available The wheat midge, Sitodiplosis mosellana, is an important pest in Northern China. We tested the hypothesis that the population structure of this species arises during a range expansion over the past 30 years. This study used microsatellite and mitochondrial loci to conduct population genetic analysis of S. mosellana across its distribution range in China. We found strong genetic structure among the 16 studied populations, including two genetically distinct groups (the eastern and western groups, broadly consistent with the geography and habitat fragmentation. These results underline the importance of natural barriers in impeding dispersal and gene flow of S. mosellana populations. Low to moderate genetic diversity among the populations and moderate genetic differentiation (F ST = 0.117 between the two groups were also found. The populations in the western group had lower genetic diversity, higher genetic differentiation and lower gene flow (F ST = 0.116, Nm = 1.89 than those in the eastern group (F ST = 0.049, Nm = 4.91. Genetic distance between populations was positively and significantly correlated with geographic distance (r = 0.56, P<0.001. The population history of this species provided no evidence for population expansion or bottlenecks in any of these populations. Our data suggest that the distribution of genetic diversity, genetic differentiation and population structure of S. mosellana have resulted from a historical event, reflecting its adaptation to diverse habitats and forming two different gene pools. These results may be the outcome of a combination of restricted gene flow due to geographical and environmental factors, population history, random processes of genetic drift and individual dispersal patterns. Given the current risk status of this species in China, this study can offer useful information for forecasting outbreaks and designing effective pest management programs.

Light habitat, structure, diversity and dynamic of the tropical dry forest

Directory of Open Access Journals (Sweden)

Omar Melo-Cruz

2017-01-01

Full Text Available Tropical dry forests are complex and fragile ecosystems with high anthropic intervention and restricted reproductive cycles. These have unique richness, structural diversity, physiological and phenological . This research was executed  in the Upper Magdalena Valley, in four forest fragments with different successional stages. In each fragment four permanent plots of 0.25 ha were established and lighting habitat associated with richness, relative abundance and rarity of species. The forest dynamics included the mortality, recruitment and diameter growth for a period of 5.25 years. The species rischness found in the mature riparian forestis higher than that reported in other studies of similar areas in Valle del Cauca and the Atlantic coast.  The values of richness, diversity and rarity species are more evidenced  than the magnitudes found in  drier areas of Tolima. The structure, diversity and dynamics of forests were correlated with the lighting habitat, showing differences in canopy architecture and its role in the capture and absorption of radiation. Forests with dense canopy have limited availability of photosynthetically active radiation in understory related low species richness, while illuminated undergrowth are richer and heterogeneous.

Structure, function and diversity of the healthy human microbiome.

Science.gov (United States)

2012-06-13

Studies of the human microbiome have revealed that even healthy individuals differ remarkably in the microbes that occupy habitats such as the gut, skin and vagina. Much of this diversity remains unexplained, although diet, environment, host genetics and early microbial exposure have all been implicated. Accordingly, to characterize the ecology of human-associated microbial communities, the Human Microbiome Project has analysed the largest cohort and set of distinct, clinically relevant body habitats so far. We found the diversity and abundance of each habitat's signature microbes to vary widely even among healthy subjects, with strong niche specialization both within and among individuals. The project encountered an estimated 81-99% of the genera, enzyme families and community configurations occupied by the healthy Western microbiome. Metagenomic carriage of metabolic pathways was stable among individuals despite variation in community structure, and ethnic/racial background proved to be one of the strongest associations of both pathways and microbes with clinical metadata. These results thus delineate the range of structural and functional configurations normal in the microbial communities of a healthy population, enabling future characterization of the epidemiology, ecology and translational applications of the human microbiome.

Effects of timber harvest on structural diversity and species composition in hardwood forests

Directory of Open Access Journals (Sweden)

FARZAM TAVANKAR

2015-04-01

Full Text Available Tavankar F, Bonyad AE. 2015. Effects of timber harvest on structural diversity and species composition in hardwood forests. Biodiversitas 16: 1-9. Forest management leads to changes in structure and species composition of stands. In this research vertical and horizontal structure and species composition were compared in two harvested and protected stands in the Caspian forest of Iran. The results indicated the tree and seedling density, total basal area and stand volume was significantly (P < 0.01 higher in the protected stand. The Fagus orientalis L. had the most density and basal area in the both stands. Species importance value (SIV of Fagus orientalis in the protected stand (92.5 was higher than in the harvested stand (88.5. While, the SIV of shade-intolerant tree species such as Acer insigne, Acer cappadocicum and Alnus subcordata was higher in the harvested stand. The density of trees and seedling of rare tree species, such as Ulmus glabra, Tilia begonifolia, Zelkova caprinifolia and Fraxinus coriarifolia, was also higher in the protected stand. The Shannon-Wiener diversity index in the protected stand (0.84 was significantly higher (P < 0.01 than in the harvested stand (0.72. The highest diversity value in the harvested stand was observed in DBH of 10-40 cm class, while DBH of 40-70 cm had the highest diversity value in the protected stand.

Genetic diversity and population structure of Pisum sativum accessions for marker-trait association of lipid content

Directory of Open Access Journals (Sweden)

Sajjad Ahmad

2015-06-01

Full Text Available Field pea (Pisum sativum L. is an important protein-rich pulse crop produced globally. Increasing the lipid content of Pisum seeds through conventional and contemporary molecular breeding tools may bring added value to the crop. However, knowledge about genetic diversity and lipid content in field pea is limited. An understanding of genetic diversity and population structure in diverse germplasm is important and a prerequisite for genetic dissection of complex characteristics and marker-trait associations. Fifty polymorphic microsatellite markers detecting a total of 207 alleles were used to obtain information on genetic diversity, population structure and marker-trait associations. Cluster analysis was performed using UPGMA to construct a dendrogram from a pairwise similarity matrix. Pea genotypes were divided into five major clusters. A model-based population structure analysis divided the pea accessions into four groups. Percentage lipid content in 35 diverse pea accessions was used to find potential associations with the SSR markers. Markers AD73, D21, and AA5 were significantly associated with lipid content using a mixed linear model (MLM taking population structure (Q and relative kinship (K into account. The results of this preliminary study suggested that the population could be used for marker-trait association mapping studies.

A huge renal capsular leiomyoma mimicking retroperitoneal sarcoma

Directory of Open Access Journals (Sweden)

Lal Anupam

2009-01-01

Full Text Available A huge left renal capsular leiomyoma mimicking retroperitoneal sarcoma presented in a patient as an abdominal mass. Computed tomography displayed a large heterogeneous retro-peritoneal mass in the left side of the abdomen with inferior and medial displacement as well as loss of fat plane with the left kidney. Surgical exploration revealed a capsulated mass that was tightly adherent to the left kidney; therefore, total tumor resection with radical left nephrectomy was performed. Histopathology ultimately confirmed the benign nature of the mass. This is the largest leiomyoma reported in literature to the best of our knowledge.

A young woman with a huge paratubal cyst

Directory of Open Access Journals (Sweden)

Ceren Golbasi

2016-09-01

Full Text Available Paratubal cysts are asymptomatic embryological remnants. These cysts are usually diagnosed during adolescence and reproductive age. In general, their sizes are small but can be complicated by rupture, torsion, or hemorrhage. Paratubal cysts are often discovered fortuitously on routine ultrasound examination. We report a 19-year-old female patient who presented with irregular menses and abdominal pain. Ultrasound examination revealed a huge cystic mass at the right adnexial area. The diagnosis was confirmed as paratubal cyst during laporotomy and, hence, cystectomy and right salpingectomy were performed. [Cukurova Med J 2016; 41(3.000: 573-576

The therapy for huge goiter together with hyperthyroidism through 131I case studies

International Nuclear Information System (INIS)

He Jianhua; Yu Wencai; Zeng Qingwen; Wu Congjun

2001-01-01

Objective: 214 cases of the treatment of huge goiter with hyperthyroidism are revised to collect clinic material for the improvement of therapy to hyperthyroidism indications through 131 I. Methods: In all of these cases, patients take a full dose of 131 I based on MC Garack's formula for one time. Results: Among them, 154 resolved, accounting for 72%, 139 of the cases were reduced to normal size, which accounted for 64.9% of the patients. Only 114 cases of patients had side-effect, and during one year 12.1% of them have symptoms of hypothyroidism. Conclusion: The statistics shows that 131 I is convenient, safe, well and with reduces suffering from treating huge goiter with hyperthyroidism

Understanding the genetic diversity and population structure of yam (Dioscorea alata L.) using microsatellite markers

Science.gov (United States)

Arnau, Gemma; MN, Sheela; Chair, Hana; Lebot, Vincent; K, Abraham; Perrier, Xavier; Petro, Dalila; Penet, Laurent; Pavis, Claudie

2017-01-01

Yams (Dioscorea sp.) are staple food crops for millions of people in tropical and subtropical regions. Dioscorea alata, also known as greater yam, is one of the major cultivated species and most widely distributed throughout the tropics. Despite its economic and cultural importance, very little is known about its origin, diversity and genetics. As a consequence, breeding efforts for resistance to its main disease, anthracnose, have been fairly limited. The objective of this study was to contribute to the understanding of D. alata genetic diversity by genotyping 384 accessions from different geographical regions (South Pacific, Asia, Africa and the Caribbean), using 24 microsatellite markers. Diversity structuration was assessed via Principal Coordinate Analysis, UPGMA analysis and the Bayesian approach implemented in STRUCTURE. Our results revealed the existence of a wide genetic diversity and a significant structuring associated with geographic origin, ploidy levels and morpho-agronomic characteristics. Seventeen major groups of genetically close cultivars have been identified, including eleven groups of diploid cultivars, four groups of triploids and two groups of tetraploids. STRUCTURE revealed the existence of six populations in the diploid genetic pool and a few admixed cultivars. These results will be very useful for rationalizing D. alata genetic resources in breeding programs across different regions and for improving germplasm conservation methods. PMID:28355293

Huge Tongue Lipoma: A Case Report

Directory of Open Access Journals (Sweden)

Mohammad Ali Damghani

2015-03-01

Full Text Available Introduction: Lipomas are among the most common tumors of the human body. However, they are uncommon in the oral cavity and are observed as slow growing, painless, and asymptomatic yellowish submucosal masses. Surgical excision is the treatment of choice and recurrence is not expected.    Case Report: The case of a 30-year-old woman with a huge lipoma on the tip of her tongue since 3 years, is presented. She had difficulty with speech and mastication because the tongue tumor was filling the oral cavity. Clinical examination revealed a yellowish lesion, measuring 8 cm in maximum diameter, protruding from the lingual surface. The tumor was surgically excised with restoration of normal tongue function and histopathological examination of the tumor confirmed that it was a lipoma.   Conclusion:  Tongue lipoma is rarely seen and can be a cause of macroglossia. Surgical excision for lipoma is indicated for symptomatic relief and exclusion of associated malignancy.

The influence of compositional and structural diversity on forest productivity

Science.gov (United States)

James N. Long; John D. Shaw

2010-01-01

Data from ~1500 ponderosa pine (Pinus ponderosa C. Lawson) stands in the western United States were used to examine the potential influence of compositional and structural diversity on forest productivity. Relative density, height and site quality were combined in a conceptually sound expression of the relationship between growth and growing stock for ponderosa pine-...

Diversity and genetic structure of jenipapo (Genipa americana L. Brazilian accessions

Directory of Open Access Journals (Sweden)

Ana Veruska Cruz da Silva

2014-10-01

Full Text Available Usually known as jenipapo, Genipa americana L. is a Rubiaceae Brazilian native species. It is an important species in the restoration of Brazilian riparian forests and is one of the most promising fruit trees for sustainable harvesting programs. In this study we provide the first data on the genetic diversity and structure of a Jenipapo Germplasm Bank using inter simple sequence repeat (ISSR markers. We evaluated 160 accessions from wild populations, and the data generated from 12 ISSR primers were used to determine genetic variability via a model-based Bayesian procedure (Structure and molecular variance analysis. In addition, Shannon index, genetic diversity and Jaccard coefficients were estimated. A total of 12 primers were used, which generated 123 polymorphic fragments. Four groups were formed from the analysis of the fragments, and the CR1-2 genotype was isolated, being more divergent than the other genotypes.

Assessment of genetic diversity and population structure of Vietnamese indigenous cattle populations by microsatellites

DEFF Research Database (Denmark)

Pham, Lan Doan; Do, Duy Ngoc; Binh, Nguyen Trong

2013-01-01

Cattle play a very important role in agriculture and food security in Vietnam. A high level of cattle diversity exists and serves different needs of Vietnamese cattle keepers but has not yet been molecularly characterized. This study evaluates the genetic diversity and structure of Vietnamese...... geographic distances. Structure analysis indicated five homogeneous clusters. The Brahman, Lang Son, Ha Giang and U Dau Riu cattle were assigned to independent clusters while Nghe An, Thanh Hoa and Phu Yen cattle were grouped in a single cluster. We conclude that Vietnamese indigenous cattle have high levels...

Scale-Dependence of Processes Structuring Dung Beetle Metacommunities Using Functional Diversity and Community Deconstruction Approaches

Science.gov (United States)

da Silva, Pedro Giovâni; Hernández, Malva Isabel Medina

2015-01-01

Community structure is driven by mechanisms linked to environmental, spatial and temporal processes, which have been successfully addressed using metacommunity framework. The relative importance of processes shaping community structure can be identified using several different approaches. Two approaches that are increasingly being used are functional diversity and community deconstruction. Functional diversity is measured using various indices that incorporate distinct community attributes. Community deconstruction is a way to disentangle species responses to ecological processes by grouping species with similar traits. We used these two approaches to determine whether they are improvements over traditional measures (e.g., species composition, abundance, biomass) for identification of the main processes driving dung beetle (Scarabaeinae) community structure in a fragmented mainland-island landscape in southern Brazilian Atlantic Forest. We sampled five sites in each of four large forest areas, two on the mainland and two on the island. Sampling was performed in 2012 and 2013. We collected abundance and biomass data from 100 sampling points distributed over 20 sampling sites. We studied environmental, spatial and temporal effects on dung beetle community across three spatial scales, i.e., between sites, between areas and mainland-island. The γ-diversity based on species abundance was mainly attributed to β-diversity as a consequence of the increase in mean α- and β-diversity between areas. Variation partitioning on abundance, biomass and functional diversity showed scale-dependence of processes structuring dung beetle metacommunities. We identified two major groups of responses among 17 functional groups. In general, environmental filters were important at both local and regional scales. Spatial factors were important at the intermediate scale. Our study supports the notion of scale-dependence of environmental, spatial and temporal processes in the distribution

Molecular genetic diversity and genetic structure of Vietnamese indigenous pig populations

DEFF Research Database (Denmark)

Pham, L. D.; Do, Duy Ngoc; Nam, L. Q.

2014-01-01

The study characterized genetic diversity and genetic structure of five indigenous pig populations (Ha Lang, Muong Te, Mong Cai, Lung and Lung Pu), two wild pig populations (Vietnamese and Thai wild pigs) and an exotic pig breed (Yorkshire) using FAO/ISAG recommended 16 microsatellite markers...

How a huge HEP experiment is designed course

CERN Multimedia

CERN. Geneva HR-FAS

2007-01-01

More than twenty years after the idea of building the LHC machine was discussed in a workshop in Lausanne in 1984 for the first time, it is instructive to look back on the historical process which has led the community to where we are today with four huge detectors being commissioned and eagerly awaiting first beam collisions in 2008. The main design principles, detector features and performance characteristics of the ATLAS and CMS detectors will be briefly covered in these two lectures with, as an interlude, a wonderful DVD from ATLAS outreach depicting how particles interact and are detected in the various components of the experiments.

Diversity of microbial plankton across the Three Gorges Dam of the Yangtze River, China

Directory of Open Access Journals (Sweden)

Shang Wang

2012-05-01

Full Text Available The Three Gorges Dam (TGD of the Yangtze River, China, is one of the largest irrigation and hydroelectric engineering projects in the world. The effects of huge man-made projects like TGD on fauna and macrophyte are obvious, mainly through changes of water dynamics and flow pattern; however, it is less clear how microorganisms respond to such changes. This research was aimed to examine differences in microbial diversity at different seasons and locations (in front of and behind the TGD. In addition, differences between particle-attached and free-living communities were also examined. The community structures of total and potentially active microorganisms in the water columns behind and in front of the TGD were analyzed with the DNA- and RNA-based 16S rRNA gene phylogenetic approaches over three different seasons. Clone libraries of 16S rRNA genes were prepared after amplification from extracted DNA and, for some samples, after preparing cDNA from extracted rRNA. Differences were observed between sites at different seasons and between free-living and particle-attached communities. Both bacterial and archaeal communities were more diverse in summer than in winter, due to higher nutrient levels and warmer temperature in summer than in winter. Particle-attached microorganisms were more diverse than free-living communities, possibly because of higher nutrient levels and heterogeneous geochemical micro-environments in particles. Spatial variations in bacterial community structure were observed, i.e., the water reservoir behind the TGD (upstream hosted more diverse bacterial populations than in front of the dam (downstream, because of diverse sources of sediments and waters from upstream to the reservoir. These results have important implications for our understanding of responses of microbial communities to environmental changes in river ecosystems affected by dam construction.

Structure, composition and diversity of the vegetation of hub dam catchment area, pakistan

International Nuclear Information System (INIS)

Shaukat, S.; Khan, M.A.

2014-01-01

A study of vegetation structure, composition and diversity of Hub-dam catchment area was conducted. A total of 106 species were recorded of which 57 were annuals while 49 were perennials. The vegetation was dominated by small trees and shrubs. Spatial patterns within-community of plant populations using variance/mean ratio and Morisita's index was also investigated. Of the 14 perennial species investigated seven (Barleria acanthoides, Grewia tenax, Indigofera oblongifolia, Aerva persica, Rhazya stricta, Iphiona grantioides and Cymbopogon jwarancusa) predominately exhibited aggregated pattern. Four species (Acacia senegal, Prosopis juliflora, Salvadora oleoides and Calotropis procera) usually exhibited random distribution but infrequently aggregated pattern. Three species (Senna holosericea, Zizyphus nummularia and Vernonia cinerescens) showed aggregated pattern or random distribution more or less equally often. The distribution pattern of vegetation composition and the underlying environmental gradients, correspondence analysis (CA) ordination and canonical correspondence analysis (CCA) were employed. Group structure inherent in the vegetation was disclosed using Ward's agglomerative cluster analysis. Species diversity was measured and diversity was averaged for each group. Diversity of group I (Acacia senegal and Prosopis juliflora community type) was highest because this community included a number of mid-succession species, while diversity was lowest for group 4 (Prosopis juliflora and Capparis decidua community type) as this community was highly disturbed. In the climax community (group 3), the diversity level slightly decreased, suggesting the monopolization of resources by this community. Four major community types were recognized by Ward's cluster analysis, each of which was associated with particular topographic-edaphic factors, while one was mainly governed by anthropogenic disturbance. Biological spectrum constructed for the flora showed dominance of

Genetic diversity and population structure in Polygonum cespitosum: insights to an ongoing plant invasion.

Directory of Open Access Journals (Sweden)

Silvia Matesanz

Full Text Available Molecular markers can help elucidate how neutral evolutionary forces and introduction history contribute to genetic variation in invaders. We examined genetic diversity, population structure and colonization patterns in the invasive Polygonum cespitosum, a highly selfing, tetraploid Asian annual introduced to North America. We used nine diploidized polymorphic microsatellite markers to study 16 populations in the introduced range (northeastern North America, via the analyses of 516 individuals, and asked the following questions: 1 Do populations have differing levels of within-population genetic diversity? 2 Do populations form distinct genetic clusters? 3 Does population structure reflect either geographic distances or habitat similarities? We found low heterozygosity in all populations, consistent with the selfing mating system of P. cespitosum. Despite the high selfing levels, we found substantial genetic variation within and among P. cespitosum populations, based on the percentage of polymorphic loci, allelic richness, and expected heterozygosity. Inferences from individual assignment tests (Bayesian clustering and pairwise FST values indicated high among-population differentiation, which indicates that the effects of gene flow are limited relative to those of genetic drift, probably due to the high selfing rates and the limited seed dispersal ability of P. cespitosum. Population structure did not reflect a pattern of isolation by distance nor was it related to habitat similarities. Rather, population structure appears to be the result of the random movement of propagules across the introduced range, possibly associated with human dispersal. Furthermore, the high population differentiation, genetic diversity, and fine-scale genetic structure (populations founded by individuals from different genetic sources in the introduced range suggest that multiple introductions to this region may have occurred. High genetic diversity may further

Parasites affect food web structure primarily through increased diversity and complexity.

Directory of Open Access Journals (Sweden)

Jennifer A Dunne

Full Text Available Comparative research on food web structure has revealed generalities in trophic organization, produced simple models, and allowed assessment of robustness to species loss. These studies have mostly focused on free-living species. Recent research has suggested that inclusion of parasites alters structure. We assess whether such changes in network structure result from unique roles and traits of parasites or from changes to diversity and complexity. We analyzed seven highly resolved food webs that include metazoan parasite data. Our analyses show that adding parasites usually increases link density and connectance (simple measures of complexity, particularly when including concomitant links (links from predators to parasites of their prey. However, we clarify prior claims that parasites "dominate" food web links. Although parasites can be involved in a majority of links, in most cases classic predation links outnumber classic parasitism links. Regarding network structure, observed changes in degree distributions, 14 commonly studied metrics, and link probabilities are consistent with scale-dependent changes in structure associated with changes in diversity and complexity. Parasite and free-living species thus have similar effects on these aspects of structure. However, two changes point to unique roles of parasites. First, adding parasites and concomitant links strongly alters the frequency of most motifs of interactions among three taxa, reflecting parasites' roles as resources for predators of their hosts, driven by trophic intimacy with their hosts. Second, compared to free-living consumers, many parasites' feeding niches appear broader and less contiguous, which may reflect complex life cycles and small body sizes. This study provides new insights about generic versus unique impacts of parasites on food web structure, extends the generality of food web theory, gives a more rigorous framework for assessing the impact of any species on trophic

Genetic Diversity and Population Structure of F3:6 Nebraska Winter Wheat Genotypes Using Genotyping-By-Sequencing.

Science.gov (United States)

Eltaher, Shamseldeen; Sallam, Ahmed; Belamkar, Vikas; Emara, Hamdy A; Nower, Ahmed A; Salem, Khaled F M; Poland, Jesse; Baenziger, Peter S

2018-01-01

The availability of information on the genetic diversity and population structure in wheat ( Triticum aestivum L.) breeding lines will help wheat breeders to better use their genetic resources and manage genetic variation in their breeding program. The recent advances in sequencing technology provide the opportunity to identify tens or hundreds of thousands of single nucleotide polymorphism (SNPs) in large genome species (e.g., wheat). These SNPs can be utilized for understanding genetic diversity and performing genome wide association studies (GWAS) for complex traits. In this study, the genetic diversity and population structure were investigated in a set of 230 genotypes (F 3:6 ) derived from various crosses as a prerequisite for GWAS and genomic selection. Genotyping-by-sequencing provided 25,566 high-quality SNPs. The polymorphism information content (PIC) across chromosomes ranged from 0.09 to 0.37 with an average of 0.23. The distribution of SNPs markers on the 21 chromosomes ranged from 319 on chromosome 3D to 2,370 on chromosome 3B. The analysis of population structure revealed three subpopulations (G1, G2, and G3). Analysis of molecular variance identified 8% variance among and 92% within subpopulations. Of the three subpopulations, G2 had the highest level of genetic diversity based on three genetic diversity indices: Shannon's information index ( I ) = 0.494, diversity index ( h ) = 0.328 and unbiased diversity index (uh) = 0.331, while G3 had lowest level of genetic diversity ( I = 0.348, h = 0.226 and uh = 0.236). This high genetic diversity identified among the subpopulations can be used to develop new wheat cultivars.

Population structure, genetic diversity and downy mildew resistance among Ocimum species germplasm.

Science.gov (United States)

Pyne, Robert M; Honig, Josh A; Vaiciunas, Jennifer; Wyenandt, Christian A; Simon, James E

2018-04-23

The basil (Ocimum spp.) genus maintains a rich diversity of phenotypes and aromatic volatiles through natural and artificial outcrossing. Characterization of population structure and genetic diversity among a representative sample of this genus is severely lacking. Absence of such information has slowed breeding efforts and the development of sweet basil (Ocimum basilicum L.) with resistance to the worldwide downy mildew epidemic, caused by the obligate oomycete Peronospora belbahrii. In an effort to improve classification of relationships 20 EST-SSR markers with species-level transferability were developed and used to resolve relationships among a diverse panel of 180 Ocimum spp. accessions with varying response to downy mildew. Results obtained from nested Bayesian model-based clustering, analysis of molecular variance and unweighted pair group method using arithmetic average (UPGMA) analyses were synergized to provide an updated phylogeny of the Ocimum genus. Three (major) and seven (sub) population (cluster) models were identified and well-supported (P UPGMA analysis provided best resolution for the 36-accession, DM resistant k3 cluster with consistently strong bootstrap support. Although the k3 cluster is a rich source of DM resistance introgression of resistance into the commercially important k1 accessions is impeded by reproductive barriers as demonstrated by multiple sterile F1 hybrids. The k2 cluster located between k1 and k3, represents a source of transferrable tolerance evidenced by fertile backcross progeny. The 90-accession k1 cluster was largely susceptible to downy mildew with accession 'MRI' representing the only source of DM resistance. High levels of genetic diversity support the observed phenotypic diversity among Ocimum spp. accessions. EST-SSRs provided a robust evaluation of molecular diversity and can be used for additional studies to increase resolution of genetic relationships in the Ocimum genus. Elucidation of population structure

An architecture for diversity-aware search for medical web content.

Science.gov (United States)

Denecke, K

2012-01-01

The Web provides a huge source of information, also on medical and health-related issues. In particular the content of medical social media data can be diverse due to the background of an author, the source or the topic. Diversity in this context means that a document covers different aspects of a topic or a topic is described in different ways. In this paper, we introduce an approach that allows to consider the diverse aspects of a search query when providing retrieval results to a user. We introduce a system architecture for a diversity-aware search engine that allows retrieving medical information from the web. The diversity of retrieval results is assessed by calculating diversity measures that rely upon semantic information derived from a mapping to concepts of a medical terminology. Considering these measures, the result set is diversified by ranking more diverse texts higher. The methods and system architecture are implemented in a retrieval engine for medical web content. The diversity measures reflect the diversity of aspects considered in a text and its type of information content. They are used for result presentation, filtering and ranking. In a user evaluation we assess the user satisfaction with an ordering of retrieval results that considers the diversity measures. It is shown through the evaluation that diversity-aware retrieval considering diversity measures in ranking could increase the user satisfaction with retrieval results.

Huge gastric diospyrobezoars successfully treated by oral intake and endoscopic injection of Coca-Cola.

Science.gov (United States)

Chung, Y W; Han, D S; Park, Y K; Son, B K; Paik, C H; Jeon, Y C; Sohn, J H

2006-07-01

A diospyrobezoar is a type of phytobezoar that is considered to be harder than any other types of phytobezoars. Here, we describe a new treatment modality, which effectively and easily disrupted huge gastric diospyrobezoars. A 41-year-old man with a history of diabetes mellitus was admitted with lower abdominal pain and vomiting. Upper gastrointestinal endoscopy revealed three huge, round diospyrobezoars in the stomach. He was made to drink two cans of Coca-Cola every 6 h. At endoscopy the next day, the bezoars were partially dissolved and turned to be softened. We performed direct endoscopic injection of Coca-Cola into each bezoar. At repeated endoscopy the next day, the bezoars were completely dissolved.

Mini Heme-Proteins: Designability of Structure and Diversity of Functions.

Science.gov (United States)

Rai, Jagdish

2017-08-30

Natural heme proteins may have heme bound to poly-peptide chain as a cofactor via noncovalent forces or heme as a prosthetic group may be covalently bound to the proteins. Nature has used porphyrins in diverse functions like electron transfer, oxidation, reduction, ligand binding, photosynthesis, signaling, etc. by modulating its properties through diverse protein matrices. Synthetic chemists have tried to utilize these molecules in equally diverse industrial and medical applications due to their versatile electro-chemical and optical properties. The heme iron has catalytic activity which can be modulated and enhanced for specific applications by protein matrix around it. Heme proteins can be designed into novel enzymes for sterio specific catalysis ranging from oxidation to reduction. These designed heme-proteins can have applications in industrial catalysis and biosensing. A peptide folds around heme easily due to hydrophobic effect of the large aromatic ring of heme. The directional property of co-ordinate bonding between peptide and metal ion in heme further specifies the structure. Therefore heme proteins can be easily designed for targeted structure and catalytic activity. The central aromatic chemical entity in heme viz. porphyrin is a very ancient molecule. Its presence in the prebiotic soup and in all forms of life suggests that it has played a vital role in the origin and progressive evolution of living organisms. Porphyrin macrocycles are highly conjugated systems composed of four modified pyrrole subunits interconnected at their α -carbon atoms via methine (=CH-) bridges. Initial minimalist models of hemoproteins focused on effect of heme-ligand co-ordinate bonding on chemical reactivity, spectroscopy, electrochemistry and magnetic properties of heme. The great sensitivity of these spectroscopic features of heme to its surrounding makes them extremely useful in structural elucidation of designed heme-peptide complexes. Therefore heme proteins are

[Community structure and diversity of soil arthropods in naturally restored sandy grasslands after grazing].

Science.gov (United States)

Liu, Ren-tao; Zhao, Ha-lin; Zhao, Xue-yong

2010-11-01

Taking the Naiman Desertification Research Station under Chinese Academy of Sciences as a base, an investigation was conducted on the community structure of soil arthropods in the naturally restored sandy grasslands after different intensity grazing disturbance, with the effects of vegetation and soil on this community structure approached. In the non-grazing grassland, soil arthropods were rich in species and more in individuals, and had the highest diversity. In the restored grassland after light grazing, soil arthropods had the lowest evenness and diversity. In the restored grassland after moderate grazing, the individuals of soil arthropods were lesser but the major groups were more, and the evenness and diversity were higher. In the restored grassland after heavy grazing, the individuals of soil arthropods were more but the major groups were lesser, and the diversity was higher. Plant individuals' number, vegetation height and coverage, and soil alkalinity were the main factors affecting the soil arthropod community in naturally restored grasslands after different intensity grazing disturbance. It was implied that after 12-year exclosure of grassland, soil arthropod community could be recovered to some degree, while grazing disturbance had long-term negative effects on the arthropod community.

Population structure and genetic diversity of native and invasive populations of Solanum rostratum (Solanaceae.

Directory of Open Access Journals (Sweden)

Jiali Zhao

Full Text Available We investigate native and introduced populations of Solanum rostratum, an annual, self-compatible plant that has been introduced around the globe. This study is the first to compare the genetic diversity of Solanum rostratum between native and introduced populations. We aim to (1 determine the level of genetic diversity across the studied regions; (2 explore the likely origins of invasive populations in China; and (3 investigate whether there is the evidence of multiple introductions into China.We genotyped 329 individuals at 10 microsatellite loci to determine the levels of genetic diversity and to investigate population structure of native and introduced populations of S. rostratum. We studied five populations in each of three regions across two continents: Mexico, the U.S.A. and China.We found the highest genetic diversity among Mexican populations of S. rostratum. Genetic diversity was significantly lower in Chinese and U.S.A. populations, but we found no regional difference in inbreeding coefficients (F IS or population differentiation (F ST. Population structure analyses indicate that Chinese and U.S.A. populations are more closely related to each other than to sampled Mexican populations, revealing that introduced populations in China share an origin with the sampled U.S.A. populations. The distinctiveness between some introduced populations indicates multiple introductions of S. rostratum into China.

On diversity performance of two-element coupling element based antenna structure for mobile terminal

DEFF Research Database (Denmark)

Al-Hadi, Azremi Abdullah; Toivanen, Juha; Laitinen, Tommi

2010-01-01

.1 and the diversity gain is equal to 10.2 dB at 99% reliability level using selection combining technique across simulation and both measurement methods. The measurement techniques are compared to show how accurately the diversity performance of a mobile terminal antenna can be estimated.......In wireless communication systems, multipath interference has a significant impact on system design and performance. Fast fading is caused by the coherent summation of one or more echoes from many reflection points reaching the receive antenna. Antenna diversity can be used to mitigate multipath...... fading. The main challenge of antenna diversity in practical application is the integration of multiple antennas on a small ground plane. Two-element antenna structure based on coupling element antenna concept for diversity application has been studied in previous work and it has shown to be feasible...

Genetic Diversity and Spatial Genetic Structure of the Grassland Perennial Saxifraga granulata along Two River Systems.

Directory of Open Access Journals (Sweden)

Sascha van der Meer

Full Text Available Due to changes in land use, the natural habitats of an increasing number of plant species have become more and more fragmented. In landscapes that consist of patches of suitable habitat, the frequency and extent of long-distance seed dispersal can be expected to be an important factor determining local genetic diversity and regional population structure of the remaining populations. In plant species that are restricted to riparian habitats, rivers can be expected to have a strong impact on the dynamics and spatial genetic structure of populations as they may enable long-distance seed dispersal and thus maintain gene flow between fragmented populations. In this study, we used polymorphic microsatellite markers to investigate the genetic diversity and the spatial genetic structure of 28 populations of Saxifraga granulata along two rivers in central Belgium. We hypothesized that rivers might be essential for gene flow among increasingly isolated populations of this species. Genetic diversity was high (HS = 0.68, which to a certain extent can be explained by the octoploid nature of S. granulata in the study area. Populations along the Dijle and Demer rivers were also highly differentiated (G"ST = 0.269 and 0.164 and DEST = 0.190 and 0.124, respectively and showed significant isolation-by-distance, indicating moderate levels of gene flow primarily between populations that are geographically close to each other. Along the river Demer population genetic diversity was higher upstream than downstream, suggesting that seed dispersal via the water was not the primary mode of dispersal. Overall, these results indicate that despite increasing fragmentation populations along both rivers were highly genetically diverse. The high ploidy level and longevity of S. granulata have most likely buffered negative effects of fragmentation on genetic diversity and the spatial genetic structure of populations in riparian grasslands.

Zooplankton standing stock, community structure and diversity in the northern Arabian Sea

Digital Repository Service at National Institute of Oceanography (India)

Goswami, S.C.; Srivastava, Y.

The effects of large scale oil spill, which occurred during the Gulf War in 1991 on zooplankton standing stock, community structure and diversity in the northern Arabian Sea were studied. Surface (1-0 m) and vertical zooplankton hauls (200-0 m, 250...

[Diversity and community structure of endophytic fungi from Taxus chinensis var. mairei].

Science.gov (United States)

2014-07-01

A total of 628 endophytic fungi were isolated from 480 tissue segments of needles and branches of Taxus chinensis var. mairei. According to morphological characteristics and ITS sequences, they represented 43 taxa in 28 genera, of which 10 Hyphomycetes, 20 Coelomycetes, 12 Ascomycetes and 1 unknown fungus. Phomopsis mali was confirmed as the dominant species. In accordance with relative frequency, Alternaria alternata, Aureobasidium pullulans, Colletotrichum boninense, C. gloeosporioides, Epicoccum nigrum , Fungal sp., Fusarium lateritium, Glomerella cingulata, Magnaporthales sp. , Nigrospora oryzae, Pestalotiopsis maculiformans, P. microspora, Peyronellaea glomerata and Xylaria sp. 1 were more common in T. chinensis var. mairei. T. chinensis var. mairei were severely infected by endophytic fungi. Endophytic fungi were found in 81 percent of plant tissues with a high diversity. Distribution ranges of endophytic fungi were influenced by tissue properties. The colonization rate, richness, diversity of endophytic fungi in needles were obviously lower than in branches, and kinds of endophytic fungi between branches were more similar than those in needles, thus endophytic fungi had tissue preference. In addition, tissue age influenced the community structure of endophytic fungi. The elder branch tissues were, the higher colonization rate, richness, diversity of endophytic fungi were. Systematic studying the diversity and community structure of endophytic fungi in T. chinensis var. mairei and clarifying their distribution regularity in plant tissues would offer basic data and scientific basis for their development and utilization. Discussing the presence of fungal pathogens in healthy plant tissues would be of positive significance for source protection of T. chinensis var. mairei.

It was huge! Nursing students' first experience at AORN Congress.

Science.gov (United States)

Byrne, Michelle; Cantrell, Kelly; Fletcher, Daphne; McRaney, David; Morris, Kelly

2004-01-01

AN EXPERIENTIAL KNOWLEDGE of mentoring through nursing students' perspectives may enhance AORN's ability to recruit students to perioperative nursing and aid future planning for student involvement in the Association. IN 2003, four first-year nursing students attended the AORN Congress in Chicago with their nursing instructor and mentor. The students' experiences were captured using a thematic analysis to analyze their journals. THE FIVE COMMON THEMES identified were "it was huge," "exhibits," "student program," "exploring the city," and "suggestions for future planning."

Lack of congruence in species diversity indices and community structures of planktonic groups based on local environmental factors.

Science.gov (United States)

Doi, Hideyuki; Chang, Kwang-Hyeon; Nishibe, Yuichiro; Imai, Hiroyuki; Nakano, Shin-ichi

2013-01-01

The importance of analyzing the determinants of biodiversity and community composition by using multiple trophic levels is well recognized; however, relevant data are lacking. In the present study, we investigated variations in species diversity indices and community structures of the plankton taxonomic groups-zooplankton, rotifers, ciliates, and phytoplankton-under a range of local environmental factors in pond ecosystems. For each planktonic group, we estimated the species diversity index by using linear models and analyzed the community structure by using canonical correspondence analysis. We showed that the species diversity indices and community structures varied among the planktonic groups and according to local environmental factors. The observed lack of congruence among the planktonic groups may have been caused by niche competition between groups with similar trophic guilds or by weak trophic interactions. Our findings highlight the difficulty of predicting total biodiversity within a system, based upon a single taxonomic group. Thus, to conserve the biodiversity of an ecosystem, it is crucial to consider variations in species diversity indices and community structures of different taxonomic groups, under a range of local conditions.

Ontogenetic functional diversity: size structure of a keystone predator drives functioning of a complex ecosystem.

Science.gov (United States)

Rudolf, Volker H W; Rasmussen, Nick L

2013-05-01

A central challenge in community ecology is to understand the connection between biodiversity and the functioning of ecosystems. While traditional approaches have largely focused on species-level diversity, increasing evidence indicates that there exists substantial ecological diversity among individuals within species. By far, the largest source of this intraspecific diversity stems from variation among individuals in ontogenetic stage and size. Although such ontogenetic shifts are ubiquitous in natural communities, whether and how they scale up to influence the structure and functioning of complex ecosystems is largely unknown. Here we take an experimental approach to examine the consequences of ontogenetic niche shifts for the structure of communities and ecosystem processes. In particular we experimentally manipulated the stage structure in a keystone predator, larvae of the dragonfly Anax junius, in complex experimental pond communities to test whether changes in the population stage or size structure of a keystone species scale up to alter community structure and ecosystem processes, and how functional differences scale with relative differences in size among stages. We found that the functional role of A. junius was stage-specific. Altering what stages were present in a pond led to concurrent changes in community structure, primary producer biomass (periphyton and phytoplankton), and ultimately altered ecosystem processes (respiration and net primary productivity), indicating a strong, but stage-specific, trophic cascade. Interestingly, the stage-specific effects did not simply scale with size or biomass of the predator, but instead indicated clear ontogenetic niche shifts in ecological interactions. Thus, functional differences among stages within a keystone species scaled up to alter the functioning of entire ecosystems. Therefore, our results indicate that the classical approach of assuming an average functional role of a species can be misleading because

Continental-scale assessment of genetic diversity and population structure in quaking aspen (Populus tremuloides)

Science.gov (United States)

Colin M. Callahan; Carol A. Rowe; Ronald J. Ryel; John D. Shaw; Michael D. Madritch; Karen E. Mock

2013-01-01

Aspen populations in the south-western portion of the range are consistent with expectations for a historically stable edge, with low within-population diversity, significant geographical population structuring, and little evidence of northward expansion. Structuring within the southwestern cluster may result from distinct gene pools separated during the Pleistocene...

Forest structure and plant diversity in maritime pine (Pinus pinaster Ait.) stands in central Spain

Energy Technology Data Exchange (ETDEWEB)

Osorio, L. F.; Bravo, F.; Zaldivar, P.; Pando, V.

2009-07-01

The relationship between forest structure and plant diversity in Mediterranean Maritime pine stands (Pinus pinaster Ait.) in the Iberian Range (Spain) was studied. Forty eight stands were sampled. In each, a circular plot (15 m radius) and a transect (25*1 m{sup 2}) were established to estimate stand variables and record presence and abundance of vascular species respectively. Canonical correlation analysis (CCA), simple correlations and multiple stepwise linear regressions were used to explore the relationship between plant diversity and forest structure. Correlation between diversity measurements and stand variables is very weak, but significant correlations were found when evaluating each set of variables separately. Presence and cover of some species (for instance, Veronica arvensis L. or Micropyrum tenellum (L.) Link) is correlated with stand variables; however, determination coefficients found in step-by-step regression are not significant. (Author) 34 refs.

Land-use systems affect Archaeal community structure and functional diversity in western Amazon soils

Directory of Open Access Journals (Sweden)

Acácio Aparecido Navarrete

2011-10-01

Full Text Available The study of the ecology of soil microbial communities at relevant spatial scales is primordial in the wide Amazon region due to the current land use changes. In this study, the diversity of the Archaea domain (community structure and ammonia-oxidizing Archaea (richness and community composition were investigated using molecular biology-based techniques in different land-use systems in western Amazonia, Brazil. Soil samples were collected in two periods with high precipitation (March 2008 and January 2009 from Inceptisols under primary tropical rainforest, secondary forest (5-20 year old, agricultural systems of indigenous people and cattle pasture. Denaturing gradient gel electrophoresis of polymerase chain reaction-amplified DNA (PCR-DGGE using the 16S rRNA gene as a biomarker showed that archaeal community structures in crops and pasture soils are different from those in primary forest soil, which is more similar to the community structure in secondary forest soil. Sequence analysis of excised DGGE bands indicated the presence of crenarchaeal and euryarchaeal organisms. Based on clone library analysis of the gene coding the subunit of the enzyme ammonia monooxygenase (amoA of Archaea (306 sequences, the Shannon-Wiener function and Simpson's index showed a greater ammonia-oxidizing archaeal diversity in primary forest soils (H' = 2.1486; D = 0.1366, followed by a lower diversity in soils under pasture (H' = 1.9629; D = 0.1715, crops (H' = 1.4613; D = 0.3309 and secondary forest (H' = 0.8633; D = 0.5405. All cloned inserts were similar to the Crenarchaeota amoA gene clones (identity > 95 % previously found in soils and sediments and distributed primarily in three major phylogenetic clusters. The findings indicate that agricultural systems of indigenous people and cattle pasture affect the archaeal community structure and diversity of ammonia-oxidizing Archaea in western Amazon soils.

Genotypic diversity and clonal structure of Erigeron annuus (Asteraceae in Lithuania

Directory of Open Access Journals (Sweden)

Tunaitienė, Virginija

2014-02-01

Full Text Available This study was conducted to assess the clonal structure and genetic diversity of alien herbaceous plant species Erigeron annuus. The global warming and changes in agriculture practice in the past few decades were favourable for the expansion of this species in Lithuania. We used RAPD and ISSR assays to assess genetic variation within and among 29 populations of E. annuus. A total of 278 molecular markers were revealed. Our study detected reduced level of genetic diversity of invasive populations of E. annuus. Significant differences in DNA polymorphism among populations of E. annuus were also found. Some populations of this species are composed of genetically identical plants, while others were polymorphic. Clonal diversity of study populations ranged from 0.083 to 0.4 for both DNA marker systems. The Simpsons diversity index values ranged from 0.0 to 0.636. The average number of genotypes per population established using both assays was about 1.7. Out of 328 E. annuus individuals only 16 showed unique RAPD and 14 unique ISSR banding patterns. The remaining plants were clones of different size. The most common genotype of E. annuus identified in our study was represented by predominate in nine populations.

Forest structure in low diversity tropical forests: a study of Hawaiian wet and dry forests

Science.gov (United States)

R. Ostertag; F. Inman-Narahari; S. Cordell; C.P. Giardina; L. Sack

2014-01-01

The potential influence of diversity on ecosystem structure and function remains a topic of significant debate, especially for tropical forests where diversity can range widely. We used Center for Tropical Forest Science (CTFS) methodology to establish forest dynamics plots in montane wet forest and lowland dry forest on Hawai‘i Island. We compared the species...

Community structure and diversity of demersal fish assemblages: the role of fishery

Directory of Open Access Journals (Sweden)

Mary Labropoulou

2004-04-01

Full Text Available Seasonal experimental trawl surveys were carried out in the Northern Aegean and Thracian seas (NE Mediterranean, Greece, from summer 1990 to autumn 1993, during which a total of 172 fish species were caught. In these areas, fishing pressure is very high, since approximately 50% of the Greek otter trawl fleet operates there, producing more than 57% of the total demersal landings. Different statistics were used to assess spatial structure, seasonal changes and diversity of the demersal fish assemblages on the continental shelf and upper slope. The following measures were applied to the species abundance matrix: species diversity, species richness, evenness and dominance. The analysis of 501 bottom trawls revealed that, in general, species diversity, richness and evenness decreased with water depth, with the highest values at depths 200 m. The effect of depth on the diversity patterns observed was always significant, while seasonal trends were similar with those described for the overall diversity characteristics in each area. Classification and ordination methods showed the existence of 4 groups associated with the continental shelf and upper slope in each area. Classification of the top ranking species at each group and area revealed that commercially important species were dominant in the shallowest zone (

The Influence of Ethnic Diversity on Social Network Structure in a Common-Pool Resource System: Implications for Collaborative Management

Directory of Open Access Journals (Sweden)

Michele Barnes-Mauthe

2013-03-01

Full Text Available Social networks have recently been identified as key features in facilitating or constraining collaborative arrangements that can enhance resource governance and adaptability in complex social-ecological systems. Nonetheless, the effect of ethnicity on social network structure in an ethnically diverse common-pool resource system is virtually unknown. We characterize the entire social network of Hawaii's longline fishery, an ethnically diverse competitive pelagic fishery, and investigate network homophily, network structure, and cross-scale linkages. Results show that ethnicity significantly influences social network structure and is responsible for a homophily effect, which can create challenges for stakeholder collaboration across groups. Our analysis also suggests that ethnicity influences the formation of diverse network structures, and can affect the level of linkages to outside industry leaders, government or management officials, and members of the scientific community. This study provides the first empirical examination of the impact of ethnic diversity on resource user's social networks in the common-pool resource literature, having important implications for collaborative resource management.

Structure, diversity and evolution of protein toxins from spore-forming entomopathogenic bacteria

NARCIS (Netherlands)

Maagd, de R.A.; Bravo, A.; Berry, C.; Crickmore, N.; Schnepf, H.E.

2003-01-01

Gram-positive spore-forming entomopathogenic bacteria can utilize a large variety of protein toxins to help them invade, infect, and finally kill their hosts, through their action on the insect midgut. These toxins belong to a number of homology groups containing a diversity of protein structures

A Low Cost Structurally Optimized Design for Diverse Filter Types

Science.gov (United States)

Kazmi, Majida; Aziz, Arshad; Akhtar, Pervez; Ikram, Nassar

2016-01-01

A wide range of image processing applications deploys two dimensional (2D)-filters for performing diversified tasks such as image enhancement, edge detection, noise suppression, multi scale decomposition and compression etc. All of these tasks require multiple type of 2D-filters simultaneously to acquire the desired results. The resource hungry conventional approach is not a viable option for implementing these computationally intensive 2D-filters especially in a resource constraint environment. Thus it calls for optimized solutions. Mostly the optimization of these filters are based on exploiting structural properties. A common shortcoming of all previously reported optimized approaches is their restricted applicability only for a specific filter type. These narrow scoped solutions completely disregard the versatility attribute of advanced image processing applications and in turn offset their effectiveness while implementing a complete application. This paper presents an efficient framework which exploits the structural properties of 2D-filters for effectually reducing its computational cost along with an added advantage of versatility for supporting diverse filter types. A composite symmetric filter structure is introduced which exploits the identities of quadrant and circular T-symmetries in two distinct filter regions simultaneously. These T-symmetries effectually reduce the number of filter coefficients and consequently its multipliers count. The proposed framework at the same time empowers this composite filter structure with additional capabilities of realizing all of its Ψ-symmetry based subtypes and also its special asymmetric filters case. The two-fold optimized framework thus reduces filter computational cost up to 75% as compared to the conventional approach as well as its versatility attribute not only supports diverse filter types but also offers further cost reduction via resource sharing for sequential implementation of diversified image

Genetic diversity and structure analysis based on hordein protein polymorphism in barley landrace populations from jordan

International Nuclear Information System (INIS)

Baloch, A.W.; Ali, M.; Baloch, A.M.; Mangan, B.U.N.; Song, W

2014-01-01

Jordan is unanimously considered to be one of the centers of genetic diversity for barley, where wild and landraces of barley has been grown under different climatic conditions. The genetic diversity and genetic structure based on hordein polymorphism was assessed in 90 different accessions collected from four different sites of Jordan. A-PAGE was used to reveal hordein polymorphism among the genotypes. A total of 29 distinct bands were identified, out of them 9 bands were distinguished for D, 11 for C, and 9 for the B hordein regions. The observed genetic similarity was an exceptionally high between the populations than expected, which is probably due to high gene flow estimated between them. The genetic diversity parameters were not differ largely among the populations, indicating that local selection of a particular site did not play a key role in shaping genetic diversity. Analysis of molecular variance (AMOVA) revealed significant population structure when accessions were structured according to population site. There was 94% of hordein variation resided within the populations and only 8% present among the populations. Both Bayesian and Principale Coordinate Analysis (PCoA) concordantly demonstrated admixture genotypes of the landraces barley populations. Consequently, none of the population found to be clustered separately according to its population site. It is concluded that this approach can be useful to explore the germplasm for genetic diversity but perhaps is not suitable for determining phylogenic relations in barley. (author)

Structure of sweet potato (Ipomoea batatas) diversity in West Africa covaries with a climatic gradient.

Science.gov (United States)

Glato, Kodjo; Aidam, Atsou; Kane, Ndjido Ardo; Bassirou, Diallo; Couderc, Marie; Zekraoui, Leila; Scarcelli, Nora; Barnaud, Adeline; Vigouroux, Yves

2017-01-01

Sub-Saharan agriculture has been identified as vulnerable to ongoing climate change. Adaptation of agriculture has been suggested as a way to maintain productivity. Better knowledge of intra-specific diversity of varieties is prerequisites for the successful management of such adaptation. Among crops, root and tubers play important roles in food security and economic growth for the most vulnerable populations in Africa. Here, we focus on the sweet potato. The Sweet potato (Ipomoea batatas) was domesticated in Central and South America and was later introduced into Africa and is now cultivated throughout tropical Africa. We evaluated its diversity in West Africa by sampling a region extending from the coastal area of Togo to the northern Sahelian region of Senegal that represents a range of climatic conditions. Using 12 microsatellite markers, we evaluated 132 varieties along this gradient. Phenotypic data from field trials conducted in three seasons was also obtained. Genetic diversity in West Africa was found to be 18% lower than in America. Genetic diversity in West Africa is structured into five groups, with some groups found in very specific climatic areas, e.g. under a tropical humid climate, or under a Sahelian climate. We also observed genetic groups that occur in a wider range of climates. The genetic groups were also associated with morphological differentiation, mainly the shape of the leaves and the color of the stem or root. This particular structure of diversity along a climatic gradient with association to phenotypic variability can be used for conservation strategies. If such structure is proved to be associated with specific climatic adaptation, it will also allow developing strategies to adapt agriculture to ongoing climate variation in West Africa.

Natural selection shaped the rise and fall of passenger pigeon genomic diversity.

Science.gov (United States)

Murray, Gemma G R; Soares, André E R; Novak, Ben J; Schaefer, Nathan K; Cahill, James A; Baker, Allan J; Demboski, John R; Doll, Andrew; Da Fonseca, Rute R; Fulton, Tara L; Gilbert, M Thomas P; Heintzman, Peter D; Letts, Brandon; McIntosh, George; O'Connell, Brendan L; Peck, Mark; Pipes, Marie-Lorraine; Rice, Edward S; Santos, Kathryn M; Sohrweide, A Gregory; Vohr, Samuel H; Corbett-Detig, Russell B; Green, Richard E; Shapiro, Beth

2017-11-17

The extinct passenger pigeon was once the most abundant bird in North America, and possibly the world. Although theory predicts that large populations will be more genetically diverse, passenger pigeon genetic diversity was surprisingly low. To investigate this disconnect, we analyzed 41 mitochondrial and 4 nuclear genomes from passenger pigeons and 2 genomes from band-tailed pigeons, which are passenger pigeons' closest living relatives. Passenger pigeons' large population size appears to have allowed for faster adaptive evolution and removal of harmful mutations, driving a huge loss in their neutral genetic diversity. These results demonstrate the effect that selection can have on a vertebrate genome and contradict results that suggested that population instability contributed to this species's surprisingly rapid extinction. Copyright © 2017, American Association for the Advancement of Science.

Bacterial diversity and community structure of a sub-surface aquifer exposed to realistic low herbicide concentrations

DEFF Research Database (Denmark)

Lipthay, Julia R. de; Johnsen, Kaare; Albrechtsen, H.-J.

2004-01-01

contaminants. We examined the effect of in situ exposure to realistic low concentrations of herbicides on the microbial diversity and community structure of sub-surface sediments from a shallow aquifer near Vejen (Denmark). Three different community analyses were performed: colony morphology typing, sole...... community analyses. In contrast, no significant effect was found on the bacterial diversity, except for the culturable fraction where a significantly increased richness and Shannon index was found in the herbicide acclimated sediments. The results of this study show that in situ exposure of sub-surface...... aquifers to realistic low concentrations of herbicides may alter the overall structure of a natural bacterial community, although significant effects on the genetic diversity and carbon substrate usage cannot be detected. The observed impact was probably due to indirect effects. In future investigations...

Population genetic structure of Plasmodium falciparum across a region of diverse endemicity in West Africa

Directory of Open Access Journals (Sweden)

Mobegi Victor A

2012-07-01

Full Text Available Abstract Background Malaria parasite population genetic structure varies among areas of differing endemicity, but this has not been systematically studied across Plasmodium falciparum populations in Africa where most infections occur. Methods Ten polymorphic P. falciparum microsatellite loci were genotyped in 268 infections from eight locations in four West African countries (Republic of Guinea, Guinea Bissau, The Gambia and Senegal, spanning a highly endemic forested region in the south to a low endemic Sahelian region in the north. Analysis was performed on proportions of mixed genotype infections, genotypic diversity among isolates, multilocus standardized index of association, and inter-population differentiation. Results Each location had similar levels of pairwise genotypic diversity among isolates, although there were many more mixed parasite genotype infections in the south. Apart from a few isolates that were virtually identical, the multilocus index of association was not significant in any population. Genetic differentiation between populations was low (most pairwise FST values  Conclusions Although proportions of mixed genotype infections varied with endemicity as expected, population genetic structure was similar across the diverse sites. Very substantial reduction in transmission would be needed to cause fragmented or epidemic sub-structure in this region.

SSR and morphological trait based population structure analysis of 130 diverse flax (Linum usitatissimum L.) accessions.

Science.gov (United States)

Choudhary, Shashi Bhushan; Sharma, Hariom Kumar; Kumar, Arroju Anil; Maruthi, Rangappa Thimmaiah; Mitra, Jiban; Chowdhury, Isholeena; Singh, Binay Kumar; Karmakar, Pran Gobinda

2017-02-01

A total of 130 flax accessions of diverse morphotypes and worldwide origin were assessed for genetic diversity and population structure using 11 morphological traits and microsatellite markers (15 gSSRs and 7 EST-SSRs). Analysis performed after classifying these accessions on the basis of plant height, branching pattern, seed size, Indian/foreign origin into six categories called sub-populations viz. fibre type exotic, fibre type indigenous, intermediate type exotic, intermediate type indigenous, linseed type exotic and linseed type indigenous. The study assessed different diversity indices, AMOVA, population structure and included a principal coordinate analysis based on different marker systems. The highest diversity was exhibited by gSSR markers (SI=0.46; He=0.31; P=85.11). AMOVA based on all markers explained significant difference among fibre type, intermediate type and linseed type populations of flax. In terms of variation explained by different markers, EST-SSR markers (12%) better differentiated flax populations compared to morphological (9%) and gSSR (6%) markers at P=0.01. The maximum Nei's unbiased genetic distance (D=0.11) was observed between fibre type and linseed type exotic sub-populations based on EST-SSR markers. The combined structure analysis by using all markers grouped Indian fibre type accessions (63.4%) in a separate cluster along with the Indian intermediate type (48.7%), whereas Indian accessions (82.16%) of linseed type constituted an independent cluster. These findings were supported by the results of the principal coordinate analysis. Morphological markers employed in the study found complementary with microsatellite based markers in deciphering genetic diversity and population structure of the flax germplasm. Copyright © 2016 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.

Genetic diversity and population structure analysis to construct a core collection from a large Capsicum germplasm.

Science.gov (United States)

Lee, Hea-Young; Ro, Na-Young; Jeong, Hee-Jin; Kwon, Jin-Kyung; Jo, Jinkwan; Ha, Yeaseong; Jung, Ayoung; Han, Ji-Woong; Venkatesh, Jelli; Kang, Byoung-Cheorl

2016-11-14

Conservation of genetic diversity is an essential prerequisite for developing new cultivars with desirable agronomic traits. Although a large number of germplasm collections have been established worldwide, many of them face major difficulties due to large size and a lack of adequate information about population structure and genetic diversity. Core collection with a minimum number of accessions and maximum genetic diversity of pepper species and its wild relatives will facilitate easy access to genetic material as well as the use of hidden genetic diversity in Capsicum. To explore genetic diversity and population structure, we investigated patterns of molecular diversity using a transcriptome-based 48 single nucleotide polymorphisms (SNPs) in a large germplasm collection comprising 3,821 accessions. Among the 11 species examined, Capsicum annuum showed the highest genetic diversity (H E  = 0.44, I = 0.69), whereas the wild species C. galapagoense showed the lowest genetic diversity (H E  = 0.06, I = 0.07). The Capsicum germplasm collection was divided into 10 clusters (cluster 1 to 10) based on population structure analysis, and five groups (group A to E) based on phylogenetic analysis. Capsicum accessions from the five distinct groups in an unrooted phylogenetic tree showed taxonomic distinctness and reflected their geographic origins. Most of the accessions from European countries are distributed in the A and B groups, whereas the accessions from Asian countries are mainly distributed in C and D groups. Five different sampling strategies with diverse genetic clustering methods were used to select the optimal method for constructing the core collection. Using a number of allelic variations based on 48 SNP markers and 32 different phenotypic/morphological traits, a core collection 'CC240' with a total of 240 accessions (5.2 %) was selected from within the entire Capsicum germplasm. Compared to the other core collections, CC240 displayed higher

Interracial Friendship and Structural Diversity: Trends for Greek, Religious, and Ethnic Student Organizations

Science.gov (United States)

Park, Julie J.; Kim, Young K.

2013-01-01

This article examines how peer interactions in college organizations (Greek, ethnic, and religious) affect interracial friendships, including whether peer interaction in student organizations mediates the relationship between structural diversity and interracial friendship. Involvement in ethnic student organizations was non-significant;…

Successful Vaginal Delivery despite a Huge Ovarian Mucinous Cystadenoma Complicating Pregnancy: A Case Report

Directory of Open Access Journals (Sweden)

Dipak Mandi

2013-12-01

Full Text Available A 22-year-old patient with 9 months of amenorrhea and a huge abdominal swelling was admitted to our institution with an ultrasonography report of a multiloculated cystic space-occupying lesion, almost taking up the whole abdomen (probably of ovarian origin, along with a single live intrauterine fetus. She delivered vaginally a boy baby within 4 hours of admission without any maternal complication, but the baby had features of intrauterine growth restriction along with low birth weight. On the 8th postpartum day, the multiloculated cystic mass, which arose from the right ovary and weighed about 11 kg, was removed via laparotomy. A mucinous cystadenoma with no malignant cells in peritoneal washing was detected in histopathology examination. This report describes a rare case of a successful vaginal delivery despite a huge cystadenoma of the right ovary complicating the pregnancy.

Genetic diversity and population structure of Plasmodium falciparum in Thailand, a low transmission country.

Science.gov (United States)

Pumpaibool, Tepanata; Arnathau, Céline; Durand, Patrick; Kanchanakhan, Naowarat; Siripoon, Napaporn; Suegorn, Aree; Sitthi-Amorn, Chitr; Renaud, François; Harnyuttanakorn, Pongchai

2009-07-14

The population structure of the causative agents of human malaria, Plasmodium sp., including the most serious agent Plasmodium falciparum, depends on the local epidemiological and demographic situations, such as the incidence of infected people, the vector transmission intensity and migration of inhabitants (i.e. exchange between sites). Analysing the structure of P. falciparum populations at a large scale, such as continents, or with markers that are subject to non-neutral selection, can lead to a masking and misunderstanding of the effective process of transmission. Thus, knowledge of the genetic structure and organization of P. falciparum populations in a particular area with neutral genetic markers is needed to understand which epidemiological factors should be targeted for disease control. Limited reports are available on the population genetic diversity and structure of P. falciparum in Thailand, and this is of particular concern at the Thai-Myanmar and Thai-Cambodian borders, where there is a reported high resistance to anti-malarial drugs, for example mefloquine, with little understanding of its potential gene flow. The diversity and genetic differentiation of P. falciparum populations were analysed using 12 polymorphic apparently neutral microsatellite loci distributed on eight of the 14 different chromosomes. Samples were collected from seven provinces in the western, eastern and southern parts of Thailand. A strong difference in the nuclear genetic structure was observed between most of the assayed populations. The genetic diversity was comparable to the intermediate level observed in low P. falciparum transmission areas (average HS = 0.65 +/- 0.17), where the lowest is observed in South America and the highest in Africa. However, uniquely the Yala province, had only a single multilocus genotype present in all samples, leading to a strong geographic differentiation when compared to the other Thai populations during this study. Comparison of the genetic

Genetic structure and diversity of the black and rufous sengiin Tanzanian coastal forests

Czech Academy of Sciences Publication Activity Database

Sabuni, C. A.; Van Houtte, N.; Gryseels, S.; Maganga, S. L. S.; Makundi, R. H.; Leirs, H.; Goüy de Bellocq, Joëlle

2016-01-01

Roč. 300, č. 4 (2016), s. 305-313 ISSN 0952-8369 Institutional support: RVO:68081766 Keywords : Rhynchocyon petersi * vulnerable * conservation genetics * coastal forests * Beamys hindei * genetic structure * genetic diversity * habitat fragmentation Subject RIV: EH - Ecology, Behaviour Impact factor: 2.186, year: 2016

Structure of sweet potato (Ipomoea batatas diversity in West Africa covaries with a climatic gradient.

Directory of Open Access Journals (Sweden)

Kodjo Glato

Full Text Available Sub-Saharan agriculture has been identified as vulnerable to ongoing climate change. Adaptation of agriculture has been suggested as a way to maintain productivity. Better knowledge of intra-specific diversity of varieties is prerequisites for the successful management of such adaptation. Among crops, root and tubers play important roles in food security and economic growth for the most vulnerable populations in Africa. Here, we focus on the sweet potato. The Sweet potato (Ipomoea batatas was domesticated in Central and South America and was later introduced into Africa and is now cultivated throughout tropical Africa. We evaluated its diversity in West Africa by sampling a region extending from the coastal area of Togo to the northern Sahelian region of Senegal that represents a range of climatic conditions. Using 12 microsatellite markers, we evaluated 132 varieties along this gradient. Phenotypic data from field trials conducted in three seasons was also obtained. Genetic diversity in West Africa was found to be 18% lower than in America. Genetic diversity in West Africa is structured into five groups, with some groups found in very specific climatic areas, e.g. under a tropical humid climate, or under a Sahelian climate. We also observed genetic groups that occur in a wider range of climates. The genetic groups were also associated with morphological differentiation, mainly the shape of the leaves and the color of the stem or root. This particular structure of diversity along a climatic gradient with association to phenotypic variability can be used for conservation strategies. If such structure is proved to be associated with specific climatic adaptation, it will also allow developing strategies to adapt agriculture to ongoing climate variation in West Africa.

Spatiotemporal diversity, structure and trophic guilds of insect assemblages in a semi-arid Sabkha ecosystem

Directory of Open Access Journals (Sweden)

Haroun Chenchouni

2015-03-01

Full Text Available The current study highlights some knowledge on the diversity and structure of insect communities and trophic groups living in Sabkha Djendli (semi-arid area of Northeastern Algeria. The entomofauna was monthly sampled from March to November 2006 using pitfall traps at eight sites located at the vicinity of the Sabkha. Structural and diversity parameters (species richness, Shannon index, evenness were measured for both insect orders and trophic guilds. The canonical correspondence analysis (CCA was applied to determine how vegetation parameters (species richness and cover influence spatial and seasonal fluctuations of insect assemblages. The catches totalled 434 insect individuals classified into 75 species, 62 genera, 31 families and 7 orders, of which Coleoptera and Hymenoptera were the most abundant and constant over seasons and study stations. Spring and autumn presented the highest values of diversity parameters. Individual-based Chao-1 species richness estimator indicated 126 species for the total individuals captured in the Sabkha. Based on catch abundances, the structure of functional trophic groups was predators (37.3%, saprophages (26.7%, phytophages (20.5%, polyphages (10.8%, coprophages (4.6%; whereas in terms of numbers of species, they can be classified as phytophages (40%, predators (25.3%, polyphages (13.3%, saprophages (12%, coprophages (9.3%. The CCA demonstrated that phytophages and saprophages as well as Coleoptera and Orthoptera were positively correlated with the two parameters of vegetation, especially in spring and summer. While the abundance of coprophages was positively correlated with species richness of plants, polyphage density was positively associated with vegetation cover. The insect community showed high taxonomic and functional diversity that is closely related to diversity and vegetation cover in different stations of the wetland and seasons.

Mechanisms shaping size structure and functional diversity of phytoplankton communities in the ocean

Science.gov (United States)

Acevedo-Trejos, Esteban; Brandt, Gunnar; Bruggeman, Jorn; Merico, Agostino

2015-01-01

The factors regulating phytoplankton community composition play a crucial role in structuring aquatic food webs. However, consensus is still lacking about the mechanisms underlying the observed biogeographical differences in cell size composition of phytoplankton communities. Here we use a trait-based model to disentangle these mechanisms in two contrasting regions of the Atlantic Ocean. In our model, the phytoplankton community can self-assemble based on a trade-off emerging from relationships between cell size and (1) nutrient uptake, (2) zooplankton grazing, and (3) phytoplankton sinking. Grazing ‘pushes’ the community towards larger cell sizes, whereas nutrient uptake and sinking ‘pull’ the community towards smaller cell sizes. We find that the stable environmental conditions of the tropics strongly balance these forces leading to persistently small cell sizes and reduced size diversity. In contrast, the seasonality of the temperate region causes the community to regularly reorganize via shifts in species composition and to exhibit, on average, bigger cell sizes and higher size diversity than in the tropics. Our results raise the importance of environmental variability as a key structuring mechanism of plankton communities in the ocean and call for a reassessment of the current understanding of phytoplankton diversity patterns across latitudinal gradients. PMID:25747280

Diversity, structure and convergent evolution of the global sponge microbiome

Science.gov (United States)

Thomas, Torsten; Moitinho-Silva, Lucas; Lurgi, Miguel; Björk, Johannes R.; Easson, Cole; Astudillo-García, Carmen; Olson, Julie B.; Erwin, Patrick M.; López-Legentil, Susanna; Luter, Heidi; Chaves-Fonnegra, Andia; Costa, Rodrigo; Schupp, Peter J.; Steindler, Laura; Erpenbeck, Dirk; Gilbert, Jack; Knight, Rob; Ackermann, Gail; Victor Lopez, Jose; Taylor, Michael W.; Thacker, Robert W.; Montoya, Jose M.; Hentschel, Ute; Webster, Nicole S.

2016-01-01

Sponges (phylum Porifera) are early-diverging metazoa renowned for establishing complex microbial symbioses. Here we present a global Porifera microbiome survey, set out to establish the ecological and evolutionary drivers of these host–microbe interactions. We show that sponges are a reservoir of exceptional microbial diversity and major contributors to the total microbial diversity of the world's oceans. Little commonality in species composition or structure is evident across the phylum, although symbiont communities are characterized by specialists and generalists rather than opportunists. Core sponge microbiomes are stable and characterized by generalist symbionts exhibiting amensal and/or commensal interactions. Symbionts that are phylogenetically unique to sponges do not disproportionally contribute to the core microbiome, and host phylogeny impacts complexity rather than composition of the symbiont community. Our findings support a model of independent assembly and evolution in symbiont communities across the entire host phylum, with convergent forces resulting in analogous community organization and interactions. PMID:27306690

Spontaneous formation of structurally diverse membrane channel architectures from a single antimicrobial peptide

Science.gov (United States)

Wang, Yukun; Chen, Charles H.; Hu, Dan; Ulmschneider, Martin B.; Ulmschneider, Jakob P.

2016-11-01

Many antimicrobial peptides (AMPs) selectively target and form pores in microbial membranes. However, the mechanisms of membrane targeting, pore formation and function remain elusive. Here we report an experimentally guided unbiased simulation methodology that yields the mechanism of spontaneous pore assembly for the AMP maculatin at atomic resolution. Rather than a single pore, maculatin forms an ensemble of structurally diverse temporarily functional low-oligomeric pores, which mimic integral membrane protein channels in structure. These pores continuously form and dissociate in the membrane. Membrane permeabilization is dominated by hexa-, hepta- and octamers, which conduct water, ions and small dyes. Pores form by consecutive addition of individual helices to a transmembrane helix or helix bundle, in contrast to current poration models. The diversity of the pore architectures--formed by a single sequence--may be a key feature in preventing bacterial resistance and could explain why sequence-function relationships in AMPs remain elusive.

Genetic diversity and population structure among six cattle breeds in South Africa using a whole genome SNP panel

Directory of Open Access Journals (Sweden)

Sithembile Olga Makina

2014-09-01

Full Text Available Information about genetic diversity and population structure among cattle breeds is essential for genetic improvement, understanding of environmental adaptation as well as utilization and conservation of cattle breeds. This study investigated genetic diversity and the population structure among six cattle breeds in South African (SA including Afrikaner (n=44, Nguni (n=54, Drakensberger (n=47, Bonsmara (n=44, Angus (n=31 and Holstein (n=29. Genetic diversity within cattle breeds was analyzed using three measures of genetic diversity namely allelic richness (AR, expected heterozygosity (He and inbreeding coefficient (f. Genetic distances between breed pairs were evaluated using Nei’s genetic distance. Population structure was assessed using model-based clustering (ADMIXTURE. Results of this study revealed that the allelic richness ranged from 1.88 (Afrikaner to 1.73 (Nguni. Afrikaner cattle had the lowest level of genetic diversity (He=0.24 and the Drakensberger cattle (He=0.30 had the highest level of genetic variation among indigenous and locally-developed cattle breeds. The level of inbreeding was lower across the studied cattle breeds. As expected the average genetic distance was the greatest between indigenous cattle breeds and Bos taurus cattle breeds but the lowest among indigenous and locally-developed breeds. Model-based clustering revealed some level of admixture among indigenous and locally-developed breeds and supported the clustering of the breeds according to their history of origin. The results of this study provided useful insight regarding genetic structure of South African cattle breeds.

Managing Diversity.

Science.gov (United States)

Geber, Beverly

1990-01-01

Demographic trends imply that organizations must learn to manage a diverse work force. Ways to change organizational systems, structures, and practices to eliminate subtle barriers are awareness training, attitude change, and valuing diversity. (SK)

Linking Vegetation Structure and Spider Diversity in Riparian and Adjacent Habitats in Two Rivers of Central Argentina: An Analysis at Two Conceptual Levels.

Science.gov (United States)

Griotti, Mariana; Muñoz-Escobar, Christian; Ferretti, Nelson E

2017-08-01

The link between vegetation structure and spider diversity has been well explored in the literature. However, few studies have compared spider diversity and its response to vegetation at two conceptual levels: assemblage (species diversity) and ensemble (guild diversity). Because of this, we studied spider diversity in riparian and adjacent habitats of a river system from the Chacoan subregion in central Argentina and evaluated their linkage with vegetation structure at these two levels. To assess vegetation structure, we measured plant species richness and vegetation cover in the herb and shrub - tree layers. We collected spiders for over 6 months by using vacuum netting, sweep netting and pitfall traps. We collected 3,808 spiders belonging to 119 morphospecies, 24 families and 9 guilds. At spider assemblage level, SIMPROF analysis showed significant differences among studied habitats. At spider ensemble level, nevertheless, we found no significant differences among habitats. Concerning the linkage with vegetation structure, BIOENV test showed that spider diversity at either assemblage or ensemble level was not significantly correlated with the vegetation variables assessed. Our results indicated that spider diversity was not affected by vegetation structure. Hence, even though we found a pattern in spider assemblages among habitats, this could not be attributed to vegetation structure. In this study, we show that analyzing a community at two conceptual levels will be useful for recognizing different responses of spider communities to vegetation structure in diverse habitat types. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Genetic Diversity and Population Structure of Two Tomato Species from the Galapagos Islands

KAUST Repository

Pailles, Yveline

2017-02-15

Endemic flora of the Galapagos Islands has adapted to thrive in harsh environmental conditions. The wild tomato species from the Galapagos Islands, Solanum cheesmaniae and S. galapagense, are tolerant to various stresses, and can be crossed with cultivated tomato. However, information about genetic diversity and relationships within and between populations is necessary to use these resources efficiently in plant breeding. In this study, we analyzed 3,974 polymorphic SNP markers, obtained through the genotyping-by-sequencing technique, DArTseq, to elucidate the genetic diversity and population structure of 67 accessions of Galapagos tomatoes (compared to two S. lycopersicum varieties and one S. pimpinellifolium accession). Two clustering methods, Principal Component Analysis and STRUCTURE, showed clear distinction between the two species and a subdivision in the S. cheesmaniae group corresponding to geographical origin and age of the islands. High genetic variation among the accessions within each species was suggested by the AMOVA. High diversity in the S. cheesmaniae group and its correlation with the islands of origin were also suggested. This indicates a possible influence of the movement of the islands, from west to east, on the gene flow. Additionally, the absence of S. galapagense populations in the eastern islands points to the species divergence occurring after the eastern islands became isolated. Based on these results, it can be concluded that the population structure of the Galapagos tomatoes collection partially explains the evolutionary history of both species, knowledge that facilitates exploitation of their genetic potential for the identification of novel alleles contributing to stress tolerance.

Phylogenetic and structural diversity in the feline leukemia virus env gene.

Directory of Open Access Journals (Sweden)

Shinya Watanabe

Full Text Available Feline leukemia virus (FeLV belongs to the genus Gammaretrovirus, and causes a variety of neoplastic and non-neoplastic diseases in cats. Alteration of viral env sequences is thought to be associated with disease specificity, but the way in which genetic diversity of FeLV contributes to the generation of such variants in nature is poorly understood. We isolated FeLV env genes from naturally infected cats in Japan and analyzed the evolutionary dynamics of these genes. Phylogenetic reconstructions separated our FeLV samples into three distinct genetic clusters, termed Genotypes I, II, and III. Genotype I is a major genetic cluster and can be further classified into Clades 1-7 in Japan. Genotypes were correlated with geographical distribution; Genotypes I and II were distributed within Japan, whilst FeLV samples from outside Japan belonged to Genotype III. These results may be due to geographical isolation of FeLVs in Japan. The observed structural diversity of the FeLV env gene appears to be caused primarily by mutation, deletion, insertion and recombination, and these variants may be generated de novo in individual cats. FeLV interference assay revealed that FeLV genotypes did not correlate with known FeLV receptor subgroups. We have identified the genotypes which we consider to be reliable for evaluating phylogenetic relationships of FeLV, which embrace the high structural diversity observed in our sample. Overall, these findings extend our understanding of Gammaretrovirus evolutionary patterns in the field, and may provide a useful basis for assessing the emergence of novel strains and understanding the molecular mechanisms of FeLV transmission in cats.

Genetic structure and diversity in Juniperus communis populations in Saxony, Germany

Directory of Open Access Journals (Sweden)

Reim Stefanie

2016-06-01

Full Text Available In recent years, land use changes led to a rapid decline and fragmentation of J. communis populations in Germany. Population isolation may lead to a restricted gene flow and, further, to negative effects on genetic variation. In this study, genetic diversity and population structure in seven fragmented J. communis populations in Saxony, Germany, were investigated using nuclear microsatellites (nSSR and chloroplast single nucleotide polymorphism (cpSNP. In all Saxony J. communis populations, a high genetic diversity was determined but no population differentiation could be detected whatever method was applied (Bayesian cluster analysis, F-statistics, AMOVA. The same was true for three J. communis out-group samples originating from Italy, Slovakia and Norway, which also showed high genetic diversity and low genetic differences regarding other J. communis populations. Low genetic differentiation among the J. communis populations ascertained with nuclear and chloroplast markers indicated high levels of gene flow by pollen and also by seeds between the sampled locations. Low genetic differentiation may also provide an indicator of Juniper survival during the last glacial maximum (LGM in Europe. The results of this study serve as a basis for the implementation of appropriate conservation measures in Saxony.

A case report of surgical debulking for a huge mass of elephantiasis neuromatosa

Science.gov (United States)

Hoshi, Manabu; Ieguchi, Makoto; Taguchi, Susumu; Yamasaki, Shinya

2009-01-01

Achievement of a safe outcome for an extensive mass with hypervascularity in the extremities requires a surgical team skilled in musculoskeletal oncology. We report debulking surgery for a huge mass of elephantiasis neuromatosa in the right leg of a 56-year old man using the novel Ligasure® vessel sealing system. PMID:21139882

Partial ureterectomy for a huge primary leiomyoma of the ureter

International Nuclear Information System (INIS)

Nouralizadeh, A.; Tabib, A.; Taheri, M.; Torbati, P.M.

2010-01-01

A case of a huge primary leiomyoma of the ureter in which only partial ureterectomy was performed is presented. The benign nature of the mass was primarily confirmed with frozen section at the time of surgery and then with immunohistochemistry (IHC). To the best of our knowledge, this case is a unique form of leiomyoma of the ureter due to its large size. There have been only ten cases of primary leiomyoma of the ureter reported since 1955 and all of them were very small in size. Our case is considered to be the eleventh. (author)

Architectural design influences the diversity and structure of the built environment microbiome.

Science.gov (United States)

Kembel, Steven W; Jones, Evan; Kline, Jeff; Northcutt, Dale; Stenson, Jason; Womack, Ann M; Bohannan, Brendan Jm; Brown, G Z; Green, Jessica L

2012-08-01

Buildings are complex ecosystems that house trillions of microorganisms interacting with each other, with humans and with their environment. Understanding the ecological and evolutionary processes that determine the diversity and composition of the built environment microbiome--the community of microorganisms that live indoors--is important for understanding the relationship between building design, biodiversity and human health. In this study, we used high-throughput sequencing of the bacterial 16S rRNA gene to quantify relationships between building attributes and airborne bacterial communities at a health-care facility. We quantified airborne bacterial community structure and environmental conditions in patient rooms exposed to mechanical or window ventilation and in outdoor air. The phylogenetic diversity of airborne bacterial communities was lower indoors than outdoors, and mechanically ventilated rooms contained less diverse microbial communities than did window-ventilated rooms. Bacterial communities in indoor environments contained many taxa that are absent or rare outdoors, including taxa closely related to potential human pathogens. Building attributes, specifically the source of ventilation air, airflow rates, relative humidity and temperature, were correlated with the diversity and composition of indoor bacterial communities. The relative abundance of bacteria closely related to human pathogens was higher indoors than outdoors, and higher in rooms with lower airflow rates and lower relative humidity. The observed relationship between building design and airborne bacterial diversity suggests that we can manage indoor environments, altering through building design and operation the community of microbial species that potentially colonize the human microbiome during our time indoors.

Development of genetic diversity, differentiation and structure over 500 years in four ponderosa pine populations.

Science.gov (United States)

Lesser, M R; Parchman, T L; Jackson, S T

2013-05-01

Population history plays an important role in shaping contemporary levels of genetic variation and geographic structure. This is especially true in small, isolated range-margin populations, where effects of inbreeding, genetic drift and gene flow may be more pronounced than in large continuous populations. Effects of landscape fragmentation and isolation distance may have implications for persistence of range-margin populations if they are demographic sinks. We studied four small, disjunct populations of ponderosa pine over a 500-year period. We coupled demographic data obtained through dendroecological methods with microsatellite data to discern how and when contemporary levels of allelic diversity, among and within-population levels of differentiation, and geographic structure, arose. Alleles accumulated rapidly following initial colonization, demonstrating proportionally high levels of gene flow into the populations. At population sizes of approximately 100 individuals, allele accumulation saturated. Levels of genetic differentiation among populations (F(ST) and Jost's D(est)) and diversity within populations (F(IS)) remained stable through time. There was no evidence of geographic genetic structure at any time in the populations' history. Proportionally, high gene flow in the early stages of population growth resulted in rapid accumulation of alleles and quickly created relatively homogenous genetic patterns among populations. Our study demonstrates that contemporary levels of genetic diversity were formed quickly and early in population development. How contemporary genetic diversity accumulates over time is a key facet of understanding population growth and development. This is especially relevant given the extent and speed at which species ranges are predicted to shift in the coming century. © 2013 Blackwell Publishing Ltd.

A case report of surgical debulking for a huge mass of elephantiasis neuromatosa

Directory of Open Access Journals (Sweden)

Shinya Yamasaki

2009-07-01

Full Text Available Achievement of a safe outcome for an extensive mass with hypervascularity in the extremities requires a surgical team skilled in musculoskeletal oncology. We report debulking surgery for a huge mass of elephantiasis neuromatosa in the right leg of a 56-year old man using the novel Ligasure® vessel sealing system.

Population structure and genetic diversity characterization of a sunflower association mapping population using SSR and SNP markers.

Science.gov (United States)

Filippi, Carla V; Aguirre, Natalia; Rivas, Juan G; Zubrzycki, Jeremias; Puebla, Andrea; Cordes, Diego; Moreno, Maria V; Fusari, Corina M; Alvarez, Daniel; Heinz, Ruth A; Hopp, Horacio E; Paniego, Norma B; Lia, Veronica V

2015-02-13

Argentina has a long tradition of sunflower breeding, and its germplasm is a valuable genetic resource worldwide. However, knowledge of the genetic constitution and variability levels of the Argentinean germplasm is still scarce, rendering the global map of cultivated sunflower diversity incomplete. In this study, 42 microsatellite loci and 384 single nucleotide polymorphisms (SNPs) were used to characterize the first association mapping population used for quantitative trait loci mapping in sunflower, along with a selection of allied open-pollinated and composite populations from the germplasm bank of the National Institute of Agricultural Technology of Argentina. The ability of different kinds of markers to assess genetic diversity and population structure was also evaluated. The analysis of polymorphism in the set of sunflower accessions studied here showed that both the microsatellites and SNP markers were informative for germplasm characterization, although to different extents. In general, the estimates of genetic variability were moderate. The average genetic diversity, as quantified by the expected heterozygosity, was 0.52 for SSR loci and 0.29 for SNPs. Within SSR markers, those derived from non-coding regions were able to capture higher levels of diversity than EST-SSR. A significant correlation was found between SSR and SNP- based genetic distances among accessions. Bayesian and multivariate methods were used to infer population structure. Evidence for the existence of three different genetic groups was found consistently across data sets (i.e., SSR, SNP and SSR + SNP), with the maintainer/restorer status being the most prevalent characteristic associated with group delimitation. The present study constitutes the first report comparing the performance of SSR and SNP markers for population genetics analysis in cultivated sunflower. We show that the SSR and SNP panels examined here, either used separately or in conjunction, allowed consistent

Combinatorial Synthesis of Structurally Diverse Triazole-Bridged Flavonoid Dimers and Trimers

Directory of Open Access Journals (Sweden)

Tze Han Sum

2016-09-01

Full Text Available Flavonoids are a large family of compounds associated with a broad range of biologically useful properties. In recent years, synthetic compounds that contain two flavonoid units linked together have attracted attention in drug discovery and development projects. Numerous flavonoid dimer systems, incorporating a range of monomers attached via different linkers, have been reported to exhibit interesting bioactivities. From a medicinal chemistry perspective, the 1,2,3-triazole ring system has been identified as a particularly attractive linker moiety in dimeric derivatives (owing to several favourable attributes including proven biological relevance and metabolic stability and triazole-bridged flavonoid dimers possessing anticancer and antimalarial activities have recently been reported. However, there are relatively few examples of libraries of triazole-bridged flavonoid dimers and the diversity of flavonoid subunits present within these is typically limited. Thus, this compound type arguably remains underexplored within drug discovery. Herein, we report a modular strategy for the synthesis of novel and biologically interesting triazole-bridged flavonoid heterodimers and also very rare heterotrimers from readily available starting materials. Application of this strategy has enabled step-efficient and systematic access to a library of structurally diverse compounds of this sort, with a variety of monomer units belonging to six different structural subclasses of flavonoid successfully incorporated.

Disaster Characteristics and Mitigation Measures of Huge Glacial Debris Flows along the Sichuan-Tibet Railway

Science.gov (United States)

Liu, Jinfeng; You, Yong; Zhang, Guangze; Wang, Dong; Chen, Jiangang; Chen, Huayong

2017-04-01

The Ranwu-Tongmai section of the Sichuan-Tibet Railway passes through the Palongzangbu River basin which locates in the southeast Qinghai-Tibetan Plateau. Due to widely distributed maritime glacier in this area, the huge glacier debris flows are very developed. Consequently, the disastrous glacier debris flows with huge scale (106-108 m3 for one debris flow event) and damage become one of the key influencing factors for the route alignment of the Sichuan-Tibet Railway. The research on disaster characteristics and mitigation measures of huge glacial debris flows in the study area were conducted by the remote sensing interpretation, field investigation, parameter calculation and numerical simulation. Firstly, the distribution of the glaciers, glacier lakes and glacier debris flows were identified and classified; and the disaster characteristics for the huge glacier debris flow were analyzed and summarized. Secondly, the dynamic parameters including the flood peak discharge, debris flow peak discharge, velocity, total volume of a single debris flow event were calculated. Based on the disaster characteristics and the spatial relation with the railway, some mitigation principles and measures were proposed. Finally, the Guxiang Gully, where a huge glacier debris flow with 2*108m3 in volume occurred in 1953, was selected as a typical case to analyze its disaster characteristics and mitigation measures. The interpretation results show that the glacier area is about 970 km2 which accounts for 19% of the total study area. 130 glacier lakes and 102 glacier debris flows were identified and classified. The Sichuan-Tibet Railway passes through 43 glacier debris flows in the study area. The specific disaster characteristics were analyzed and corresponding mitigation measures were proposed for the route selection of the railway. For the Guxiang Gully, a numerical simulation to simulate the deposition condition at the alluvial fan was conducted. the simulation results show that the

Airway management of a rare huge-size supraglottic mass

International Nuclear Information System (INIS)

Abou-Zeid, Haitham A.; Al-Ghamdi, Abdel Mohsin A.; Al-Qurain, Abdel-Aziz A.; Mokhazy, Khalid M.

2006-01-01

Laser excision of a huge-sized supraglottic mass nearly obstructing the airway passage is a real challenge to anesthesiologists. Upper airway obstruction due to neoplasm in supraglottic region, is traditionally managed by preoperative tracheostomy, however, such a common procedure can potentially have an impact on long-term outcome. A 26-year-old patient presented with dysphagia caused by left cystic vallecular synovial sarcoma. The airway was successfully secured via fiberoptic bronchoscopy, followed by excision of the supraglottic tumor with CO2 laser surgery. Tracheostomy was not required. The patient was discharged from the hospital on the 4th day of surgery. This case, highlights the possibility to secure the airway passage without performing preoperative tracheostomy resulting in good outcome and short hospital stay. (author)

Low Functional β-Diversity Despite High Taxonomic β-Diversity among Tropical Estuarine Fish Communities

Science.gov (United States)

Villéger, Sébastien; Miranda, Julia Ramos; Hernandez, Domingo Flores; Mouillot, David

2012-01-01

The concept of β-diversity, defined as dissimilarity among communities, has been widely used to investigate biodiversity patterns and community assembly rules. However, in ecosystems with high taxonomic β-diversity, due to marked environmental gradients, the level of functional β-diversity among communities is largely overlooked while it may reveal processes shaping community structure. Here, decomposing biodiversity indices into α (local) and γ (regional) components, we estimated taxonomic and functional β-diversity among tropical estuarine fish communities, through space and time. We found extremely low functional β-diversity values among fish communities (diversities, α and γ functional diversities were very close to the minimal value. These patterns were caused by two dominant functional groups which maintained a similar functional structure over space and time, despite the strong dissimilarity in taxonomic structure along environmental gradients. Our findings suggest that taxonomic and functional β-diversity deserve to be quantified simultaneously since these two facets can show contrasting patterns and the differences can in turn shed light on community assembly rules. PMID:22792395

Spatial Diversity in Composition and Structure of Nekton in Ngenep Spring and its Channels, Karangploso - Malang

Directory of Open Access Journals (Sweden)

Lia Hapsari

2014-04-01

Full Text Available Water springs and its channel degradation due to anthropogenic pollution may alter the community structure of aquatic organisms. Water spring degradation tehrefore affect the quality of water as tourism resources. This study aims to investigate the changes in community structure of nekton  and determine the relationships between water quality characteristics to the diversity of nekton.  The field survey was set up in Ngenep spring and its channels. Results showed that nekton species found in Ngenep spring and its channels consists of 4 classes, 4 orders, 6 families, and 7 species with total 627 nekton samples. It is comprises of fishes, shrimp, frogs and waterstriders. Nekton diversity index (H’ in the spring and irrigation channel were in moderate level (1diversity and community structure. Clustering analyses and PCA result shows correlation pattern between nekton distribution with physico-chemical water quality parameters. However, physico-chemical water quality parameters in Ngenep springs and its channel were still optimum as nekton habitat (PP No. 82/ 2001. Keywords: Community structure, Nekton, Spatial diversity, Spring, Water channel

Structuring an integrated care system: interpreted through the enacted diversity of the actors involved – the case of a French healthcare network

Directory of Open Access Journals (Sweden)

Corinne Grenier

2011-02-01

Full Text Available Research question: We are looking at the process of structuring an integrated care system as an innovative process that swings back and forth between the diversity of the actors involved, local aspirations and national and regional regulations. We believe that innovation is enriched by the variety of the actors involved, but may also be blocked or disrupted by that diversity. Our research aims to add to other research, which, when questioning these integrated systems, analyses how the actors involved deal with diversity without really questioning it. Case study: The empirical basis of the paper is provided by case study analysis. The studied integrated care system is a French healthcare network that brings together healthcare professionals and various organisations in order to improve the way in which interventions are coordinated and formalised, in order to promote better detection and diagnosis procedures and the implementation of a care protocol. We consider this case as instrumental in developing theoretical proposals for structuring an integrated care system in light of the diversity of the actors involved. Results and discussion: We are proposing a model for structuring an integrated care system in light of the enacted diversity of the actors involved. This model is based on three factors: the diversity enacted by the leaders, three stances for considering the contribution made by diversity in the structuring process and the specific leading role played by those in charge of the structuring process.  Through this process, they determined how the actors involved in the project were differentiated, and on what basis those actors were involved. By mobilizing enacted diversity, the leaders are seeking to channel the emergence of a network in light of their own representation of that network. This model adds to published research on the structuring of integrated care systems.

Structuring an integrated care system: interpreted through the enacted diversity of the actors involved – the case of a French healthcare network

Directory of Open Access Journals (Sweden)

Corinne Grenier

2011-02-01

Full Text Available Research question: We are looking at the process of structuring an integrated care system as an innovative process that swings back and forth between the diversity of the actors involved, local aspirations and national and regional regulations. We believe that innovation is enriched by the variety of the actors involved, but may also be blocked or disrupted by that diversity. Our research aims to add to other research, which, when questioning these integrated systems, analyses how the actors involved deal with diversity without really questioning it.Case study: The empirical basis of the paper is provided by case study analysis. The studied integrated care system is a French healthcare network that brings together healthcare professionals and various organisations in order to improve the way in which interventions are coordinated and formalised, in order to promote better detection and diagnosis procedures and the implementation of a care protocol. We consider this case as instrumental in developing theoretical proposals for structuring an integrated care system in light of the diversity of the actors involved.Results and discussion: We are proposing a model for structuring an integrated care system in light of the enacted diversity of the actors involved. This model is based on three factors: the diversity enacted by the leaders, three stances for considering the contribution made by diversity in the structuring process and the specific leading role played by those in charge of the structuring process.  Through this process, they determined how the actors involved in the project were differentiated, and on what basis those actors were involved. By mobilizing enacted diversity, the leaders are seeking to channel the emergence of a network in light of their own representation of that network. This model adds to published research on the structuring of integrated care systems.

Genetic Diversity, Population Structure and Ancestral Origin of Australian Wheat

Directory of Open Access Journals (Sweden)

Reem Joukhadar

2017-12-01

Full Text Available Since the introduction of wheat into Australia by the First Fleet settlers, germplasm from different geographical origins has been used to adapt wheat to the Australian climate through selection and breeding. In this paper, we used 482 cultivars, representing the breeding history of bread wheat in Australia since 1840, to characterize their diversity and population structure and to define the geographical ancestral background of Australian wheat germplasm. This was achieved by comparing them to a global wheat collection using in-silico chromosome painting based on SNP genotyping. The global collection involved 2,335 wheat accessions which was divided into 23 different geographical subpopulations. However, the whole set was reduced to 1,544 accessions to increase the differentiation and decrease the admixture among different global subpopulations to increase the power of the painting analysis. Our analysis revealed that the structure of Australian wheat germplasm and its geographic ancestors have changed significantly through time, especially after the Green Revolution. Before 1920, breeders used cultivars from around the world, but mainly Europe and Africa, to select potential cultivars that could tolerate Australian growing conditions. Between 1921 and 1970, a dependence on African wheat germplasm became more prevalent. Since 1970, a heavy reliance on International Maize and Wheat Improvement Center (CIMMYT germplasm has persisted. Combining the results from linkage disequilibrium, population structure and in-silico painting revealed that the dependence on CIMMYT materials has varied among different Australian States, has shrunken the germplasm effective population size and produced larger linkage disequilibrium blocks. This study documents the evolutionary history of wheat breeding in Australia and provides an understanding for how the wheat genome has been adapted to local growing conditions. This information provides a guide for industry to

Genetic Diversity, Population Structure and Ancestral Origin of Australian Wheat.

Science.gov (United States)

Joukhadar, Reem; Daetwyler, Hans D; Bansal, Urmil K; Gendall, Anthony R; Hayden, Matthew J

2017-01-01

Since the introduction of wheat into Australia by the First Fleet settlers, germplasm from different geographical origins has been used to adapt wheat to the Australian climate through selection and breeding. In this paper, we used 482 cultivars, representing the breeding history of bread wheat in Australia since 1840, to characterize their diversity and population structure and to define the geographical ancestral background of Australian wheat germplasm. This was achieved by comparing them to a global wheat collection using in-silico chromosome painting based on SNP genotyping. The global collection involved 2,335 wheat accessions which was divided into 23 different geographical subpopulations. However, the whole set was reduced to 1,544 accessions to increase the differentiation and decrease the admixture among different global subpopulations to increase the power of the painting analysis. Our analysis revealed that the structure of Australian wheat germplasm and its geographic ancestors have changed significantly through time, especially after the Green Revolution. Before 1920, breeders used cultivars from around the world, but mainly Europe and Africa, to select potential cultivars that could tolerate Australian growing conditions. Between 1921 and 1970, a dependence on African wheat germplasm became more prevalent. Since 1970, a heavy reliance on International Maize and Wheat Improvement Center (CIMMYT) germplasm has persisted. Combining the results from linkage disequilibrium, population structure and in-silico painting revealed that the dependence on CIMMYT materials has varied among different Australian States, has shrunken the germplasm effective population size and produced larger linkage disequilibrium blocks. This study documents the evolutionary history of wheat breeding in Australia and provides an understanding for how the wheat genome has been adapted to local growing conditions. This information provides a guide for industry to assist with

High genetic diversity and low population structure in Porter's sunflower (Helianthus porteri).

Science.gov (United States)

Gevaert, Scott D; Mandel, Jennifer R; Burke, John M; Donovan, Lisa A

2013-01-01

Granite outcrops in the southeastern United States are rare and isolated habitats that support edaphically controlled communities dominated by herbaceous plants. They harbor rare and endemic species that are expected to have low genetic variability and high population structure due to small population sizes and their disjunct habitat. We test this expectation for an annual outcrop endemic, Helianthus porteri (Porter's sunflower). Contrary to expectation, H. porteri has relatively high genetic diversity (H e = 0.681) and relatively low genetic structure among the native populations (F ST = 0.077) when compared to 5 other Helianthus species (N = 288; 18 expressed sequence tag-SSR markers). These findings suggest greater gene flow than expected. The potential for gene flow is supported by the analysis of transplant populations established with propagules from a common source in 1959. One population established close to a native population (1.5 km) at the edge of the natural range is genetically similar to and shares rare alleles with the adjacent native population and is distinct from the central source population. In contrast, a transplant population established north of the native range has remained similar to the source population. The relatively high genetic diversity and low population structure of this species, combined with the long-term success of transplanted populations, bode well for its persistence as long as the habitat persists.

Huge hydrocephalus: definition, management, and complications.

Science.gov (United States)

Faghih Jouibari, Morteza; Baradaran, Nazanin; Shams Amiri, Rouzbeh; Nejat, Farideh; El Khashab, Mostafa

2011-01-01

Lack of comprehensive knowledge and numerous socioeconomic problems may make the parents leave hydrocephalic children untreated, leading to progressive hydrocephalus and eventual unordinary big head. Management of huge hydrocephalus (HH) differs from common hydrocephalus. We present our experience in the management of these children. HH is defined as head circumference larger than the height of the infant. Nine infants with HH have been shunted in Children's Hospital Medical Center and followed up for 0.5 to 7 years. The most common cause of hydrocephalus was aqueductal stenosis. The mean age of patients during shunting was 3 months. The head circumference ranged from 56 to 94 cm with the average of 67 cm. Cognitive statuses were appropriate based on their age in five patients. Motor development was normal only in one patient. Complications were found in most cases which included subdural effusion (six patients), shunt infection (four patients), skin injury (three patients), proximal catheter coming out of ventricle to the subdural space (two patients), and shunt exposure (one patient). Three patients died due to shunt infection and sepsis. Numerous complications may occur in patients with HH after shunt operation such as subdural effusion, ventricular collapse, electrolyte disturbance, skull deformity, scalp injury, and shunt infection. Mental and motor disabilities are very common in patients with HH. Many of these complications can be related to overdrainage; therefore, drainage control using programmable shunts is advisable.

Long-term monitoring of diversity and structure of two stands of an Atlantic Tropical Forest.

Science.gov (United States)

Diniz, Écio Souza; Carvalho, Warley Augusto Caldas; Santos, Rubens Manoel; Gastauer, Markus; Garcia, Paulo Oswaldo; Fontes, Marco Aurélio Leite; Coelho, Polyanne Aparecida; Moreira, Aline Martins; Menino, Gisele Cristina Oliveira; Oliveira-Filho, Ary Teixeira

2017-01-01

This study aimed to report the long-term monitoring of diversity and structure of the tree community in a protected semideciduous Atlantic Forest in the South of Minas Gerais State, Southeast Brazil. The study was conducted in two stands (B and C), each with 26 and 38 10 m x 30 m plots. Censuses of stand B were conducted in 2000, 2005 and 2011, and stand C in 2001, 2006 and 2011. In both stands, the most abundant and important species for biomass accumulation over the inventories were trees larger than 20 cm of diameter, which characterize advanced successional stage within the forest. The two surveyed stands within the studied forest presented differences in structure, diversity and species richness over the time.

Petroleum-influenced beach sediments of the campeche bank, Mexico: Diversity and bacterial community structure assessment

Energy Technology Data Exchange (ETDEWEB)

Rosano-Hernandez, M. C.; Ramirez-Saad, H.; Fernandez-Linares, L.; Xoconostle, B.

2009-07-01

In Mexican, either spilled or seeped out petroleum impacts nearly 300 km of the beach between Dos Bocas (Tabasco State) to Champoton town (Campeche State), where between 9 to exceptionally 9 to exceptionally 300 tonnes of oil as tar balls have been measured. This study was focused to explore, for the first time, the bacterial diversity and community structure ({alpha}-diversity)- in a kilometric scale on petroleum influenced sediments of 100 km of sandy beach. (Author)

Petroleum-influenced beach sediments of the campeche bank, Mexico: Diversity and bacterial community structure assessment

International Nuclear Information System (INIS)

Rosano-Hernandez, M. C.; Ramirez-Saad, H.; Fernandez-Linares, L.; Xoconostle, B.

2009-01-01

In Mexican, either spilled or seeped out petroleum impacts nearly 300 km of the beach between Dos Bocas (Tabasco State) to Champoton town (Campeche State), where between 9 to exceptionally 9 to exceptionally 300 tonnes of oil as tar balls have been measured. This study was focused to explore, for the first time, the bacterial diversity and community structure (α-diversity)- in a kilometric scale on petroleum influenced sediments of 100 km of sandy beach. (Author)

Structural insight into mechanism and diverse substrate selection strategy of L-ribulokinase

Energy Technology Data Exchange (ETDEWEB)

Agarwal R.; Swaminathan S.; Burley, S. K.

2012-01-01

The araBAD operon encodes three different enzymes required for catabolism of L-arabinose, which is one of the most abundant monosaccharides in nature. L-ribulokinase, encoded by the araB gene, catalyzes conversion of L-ribulose to L-ribulose-5-phosphate, the second step in the catabolic pathway. Unlike other kinases, ribulokinase exhibits diversity in substrate selectivity and catalyzes phosphorylation of all four 2-ketopentose sugars with comparable k{sub cat} values. To understand ribulokinase recognition and phosphorylation of a diverse set of substrates, we have determined the X-ray structure of ribulokinase from Bacillus halodurans bound to L-ribulose and investigated its substrate and ATP co-factor binding properties. The polypeptide chain is folded into two domains, one small and the other large, with a deep cleft in between. By analogy with related sugar kinases, we identified {sup 447}{und GG}LPQ{und K}{sup 452} as the ATP-binding motif within the smaller domain. L-ribulose binds in the cleft between the two domains via hydrogen bonds with the side chains of highly conserved Trp126, Lys208, Asp274, and Glu329 and the main chain nitrogen of Ala96. The interaction of L-ribulokinase with L-ribulose reveals versatile structural features that help explain recognition of various 2-ketopentose substrates and competitive inhibition by L-erythrulose. Comparison of our structure to that of the structures of other sugar kinases revealed conformational variations that suggest domain-domain closure movements are responsible for establishing the observed active site environment.

Huge natural gas reserves central to capacity work, construction plans in Iran

International Nuclear Information System (INIS)

Anon.

1994-01-01

Questions about oil production capacity in Iran tend to mask the country's huge potential as a producer of natural gas. Iran is second only to Russia in gas reserves, which National Iranian Gas Co. estimates at 20.7 trillion cu m. Among hurdles to Iran's making greater use of its rich endowment of natural gas are where and how to sell gas not used inside the country. The marketing logistics problem is common to other Middle East holders of gas reserves and a reason behind the recent proliferation of proposals for pipeline and liquefied natural gas schemes targeting Europe and India. But Iran's challenges are greater than most in the region. Political uncertainties and Islamic rules complicate long-term financing of transportation projects and raise questions about security of supply. As a result, Iran has remained mostly in the background of discussions about international trade of Middle Eastern gas. The country's huge gas reserves, strategic location, and existing transport infrastructure nevertheless give it the potential to be a major gas trader if the other issues can be resolved. The paper discusses oil capacity plans, gas development, gas injection for enhanced oil recovery, proposals for exports of gas, and gas pipeline plans

MtDNA genetic diversity and structure of Eurasian Collared Dove (Streptopelia decaocto).

Science.gov (United States)

Bagi, Zoltán; Dimopoulos, Evangelos Antonis; Loukovitis, Dimitrios; Eraud, Cyril; Kusza, Szilvia

2018-01-01

The Eurasian Collared Dove (Streptopelia decaocto) is one of the most successful biological invaders among terrestrial vertebrates. However, little information is available on the genetic diversity of the species. A total of 134 Eurasian Collared Doves from Europe, Asia and the Caribbean (n = 20) were studied by sequencing a 658-bp length of mitochondrial DNA (mtDNA) cytochrome oxidase I (COI). Fifty-two different haplotypes and relatively high haplotype and nucleotide diversities (Hd±SD = 0.843±0.037 and π±SD = 0.026±0.013) were detected. Haplotype Ht1 was particularly dominant: it included 44.03% of the studied individuals, and contained sequences from 75% of the studied countries. Various analyses (FST, AMOVA, STRUCTURE) distinguished 2 groups on the genetic level, designated 'A' and 'B'. Two groups were also separated in the median-joining network and the maximum likelihood tree. The results of the neutrality tests were negative (Fu FS = -25.914; Tajima D = -2.606) and significantly different from zero (P≤0.001) for group A, whereas both values for group B were positive (Fu FS = 1.811; Tajima D = 0.674) and not significant (P>0.05). Statistically significant positive autocorrelation was revealed among individuals located up to 2000 km apart (r = 0.124; P = 0.001). The present results provide the first information on the genetic diversity and structure of the Eurasian Collared Dove, and can thereby serve as a factual and comparative basis for similar studies in the future.

Higher stability in forest-atmosphere exchange observed in a structurally diverse forest.

Science.gov (United States)

Tamrakar, R.; Rayment, M.; Moyano, F.; Herbst, M.; Mund, M.; Knohl, A.

2016-12-01

We tested the hypothesis that structurally diverse forests have greater stability on exchange processes with the atmosphere compared to forests with less diverse structure. In a case study, we assessed how net ecosystem exchange (NEE) and normalized maximum assimilation (Amax) varied over time in two forests in Germany based on 11 years of continuous eddy flux measurements. The two sites differ in structure as well as in species composition: one (Hainich) is an unmanaged, uneven-aged and heterogeneous mixed beech forest (65% beech), the other (Leinefelde) is a managed, even-aged and homogeneous pure beech stand. The two selected forests are of similar mean ages (about 130 years old) and exposed to similar air temperatures and vapour pressure deficits. Even though Hainich (the unmanaged forest) received higher rainfall (720 ± 134 mm vs 599±166 mm), the soil water availability showed no significant difference between both sites. Based on detailed biomass inventory, trees in Hainich are well distributed in all diameter at breast height (dbh) classes (10 to 90cm dbh) whereas in Leinefelde (the managed forest) trees are mostly confined to dbh classes of 40 to 55 cm. Our results showed a strong difference in inter-annual variability of NEE, which was lower in the unmanaged than in the managed site (coefficient of variation (CV) of 0.13 and 0.27, respectively). The lowest NEE was observed in both sites in 2004, a mast year and a year after the strong summer drought of 2003. The variation in the inter-annual normalized maximum assimilation (Amax) was lower in Hainich (standard deviation of 2.5 compared to 3.9 µmol m-2 s-1). Also, the seasonal course of Amax differed between the two forests which could explain why the mixed forest was more affected by the late summer drought of 2003, despite showing a more conservative carbon budget than the pure stand in the long term. The interannual anomaly in Amax was correlated with fruit production, the latter being larger in

A huge bladder calculus causing acute renal failure.

Science.gov (United States)

Komeya, Mitsuru; Sahoda, Tamami; Sugiura, Shinpei; Sawada, Takuto; Kitami, Kazuo

2013-02-01

A 81-year-old male was referred to our emergency outpatient unit due to acute renal failure. The level of serum creatinine was 276 μmol/l. A CT scan showed bilateral hydronephroureter, large bladder stone (7 cm × 6 cm × 6 cm) and bladder wall thickness. He was diagnosed as post renal failure due to bilateral hydronephroureter. Large bladder stone is thought to be the cause of bilateral hydronephroureter and renal failure. To improve renal failure, we performed open cystolithotomy and urethral catheterization. Three days after the surgery, the level of serum creatinine decreased to 224 μmol/l. He was discharged from our hospital with uneventful course. Bladder calculus is thought to be a rare cause of renal failure. We summarize the characteristics of bladder calculus causing renal failure. We should keep that long-term pyuria and urinary symptom, and repeated urinary tract infection can cause huge bladder calculus and renal failure in mind.

Structural adaptations to diverse fighting styles in sexually selected weapons.

Science.gov (United States)

McCullough, Erin L; Tobalske, Bret W; Emlen, Douglas J

2014-10-07

The shapes of sexually selected weapons differ widely among species, but the drivers of this diversity remain poorly understood. Existing explanations suggest weapon shapes reflect structural adaptations to different fighting styles, yet explicit tests of this hypothesis are lacking. We constructed finite element models of the horns of different rhinoceros beetle species to test whether functional specializations for increased performance under species-specific fighting styles could have contributed to the diversification of weapon form. We find that horns are both stronger and stiffer in response to species-typical fighting loads and that they perform more poorly under atypical fighting loads, which suggests weapons are structurally adapted to meet the functional demands of fighting. Our research establishes a critical link between weapon form and function, revealing one way male-male competition can drive the diversification of animal weapons.

Partitioning the impact of environment and spatial structure on alpha and beta components of taxonomic, functional, and phylogenetic diversity in European ants.

Science.gov (United States)

Arnan, Xavier; Cerdá, Xim; Retana, Javier

2015-01-01

We analyze the relative contribution of environmental and spatial variables to the alpha and beta components of taxonomic (TD), phylogenetic (PD), and functional (FD) diversity in ant communities found along different climate and anthropogenic disturbance gradients across western and central Europe, in order to assess the mechanisms structuring ant biodiversity. To this aim we calculated alpha and beta TD, PD, and FD for 349 ant communities, which included a total of 155 ant species; we examined 10 functional traits and phylogenetic relatedness. Variation partitioning was used to examine how much variation in ant diversity was explained by environmental and spatial variables. Autocorrelation in diversity measures and each trait's phylogenetic signal were also analyzed. We found strong autocorrelation in diversity measures. Both environmental and spatial variables significantly contributed to variation in TD, PD, and FD at both alpha and beta scales; spatial structure had the larger influence. The different facets of diversity showed similar patterns along environmental gradients. Environment explained a much larger percentage of variation in FD than in TD or PD. All traits demonstrated strong phylogenetic signals. Our results indicate that environmental filtering and dispersal limitations structure all types of diversity in ant communities. Strong dispersal limitations appear to have led to clustering of TD, PD, and FD in western and central Europe, probably because different historical and evolutionary processes generated different pools of species. Remarkably, these three facets of diversity showed parallel patterns along environmental gradients. Trait-mediated species sorting and niche conservatism appear to structure ant diversity, as evidenced by the fact that more variation was explained for FD and that all traits had strong phylogenetic signals. Since environmental variables explained much more variation in FD than in PD, functional diversity should be a

Genetic diversity and structure of managed and semi-natural populations of cocoa (Theobroma cacao) in the Huallaga and Ucayali Valleys of Peru.

Science.gov (United States)

Zhang, Dapeng; Arevalo-Gardini, Enrique; Mischke, Sue; Zúñiga-Cernades, Luis; Barreto-Chavez, Alejandro; Del Aguila, Jorge Adriazola

2006-09-01

Cocoa (Theobroma cacao) is indigenous to the Amazon region of South America, and it is well known that the Peruvian Amazon harbours a large number of diverse cocoa populations. A small fraction of the diversity has been collected and maintained as an ex-situ germplasm repository in Peru. However, incorrect labelling of accessions and lack of information on genetic diversity have hindered efficient conservation and use of this germplasm. This study targeted assessment of genetic diversity and population structure in a managed and a semi-natural population. Using a capillary electrophoresis genotyping system, 105 cocoa accessions collected from the Huallaga and Ucayali valleys of Peru were fingerprinted. Based on 15 loci SSR profiles, genetic identity was examined for each accession and duplicates identified, population structure assessed and genetic diversity analysed in these two populations. Ten synonymous mislabelled groups were identified among the 105 accessions. The germplasm group in the Huallaga valley was clearly separated from the group in Ucayali valley by the Bayesian assignment test. The Huallaga group has lower genetic diversity, both in terms of allelic richness and of gene diversity, than the Ucayali group. Analysis of molecular variance suggested genetic substructure in the Ucayali group. Significant spatial correlation between genetic distance and geographical distances was detected in the Ucayali group by Mantel tests. These results substantiate the hypothesis that the Peruvian Amazon hosts a high level of cocoa genetic diversity, and the diversity has a spatial structure. The introduction of exotic seed populations into the Peruvian Amazon is changing the cocoa germplasm spectrum in this region. The spatial structure of cocoa diversity recorded here highlights the need for additional collecting and conservation measures for natural and semi-natural cocoa populations.

Molecular diversity, population structure, and linkage disequilibrium in a worldwide collection of tobacco (Nicotiana tabacum L. germplasm

Directory of Open Access Journals (Sweden)

Fricano Agostino

2012-03-01

Full Text Available Abstract Background The goals of our study were to assess the phylogeny and the population structure of tobacco accessions representing a wide range of genetic diversity; identify a subset of accessions as a core collection capturing most of the existing genetic diversity; and estimate, in the tobacco core collection, the extent of linkage disequilibrium (LD in seven genomic regions using simple sequence repeat (SSR markers. To this end, a collection of accessions were genotyped with SSR markers. Molecular diversity was evaluated and LD was analyzed across seven regions of the genome. Results A genotyping database for 312 tobacco accessions was profiled with 49 SSR markers. Principal Coordinate Analysis (PCoA and Bayesian cluster analysis revealed structuring of the tobacco population with regard to commercial classes and six main clades were identified, which correspond to "Oriental", Flue-Cured", "Burley", "Dark", "Primitive", and "Other" classes. Pairwise kinship was calculated between accessions, and an overall low level of co-ancestry was observed. A set of 89 genotypes was identified that captured the whole genetic diversity detected at the 49 loci. LD was evaluated on these genotypes, using 422 SSR markers mapping on seven linkage groups. LD was estimated as squared correlation of allele frequencies (r2. The pattern of intrachromosomal LD revealed that in tobacco LD extended up to distances as great as 75 cM with r2 > 0.05 or up to 1 cM with r2 > 0.2. The pattern of LD was clearly dependent on the population structure. Conclusions A global population of tobacco is highly structured. Clustering highlights the accessions with the same market class. LD in tobacco extends up to 75 cM and is strongly dependent on the population structure.

Responses of Soil Microbial Community Structure and Diversity to Agricultural Deintensification

Institute of Scientific and Technical Information of China (English)

ZHANG Wei-Jian; S.HU; RUI Wen-Yi; C.TU; H.G.DIAB; F.J.LOUWS; J.P.MUELLER; N.CREAMER; M.BELL; M.G.WAGGER

2005-01-01

Using a scheme of agricultural fields with progressively less intensive management (deintensification), different management practices in six agroecosystems located near Goldsboro, NC, USA were tested in a large-scale experiment, including two cash-grain cropping systems employing either tillage (CT) or no-tillage (NT), an organic farming system (OR), an integrated cropping system with animals (IN), a successional field (SU), and a plantation woodlot (WO). Microbial phospholipid fatty acid (PLFA) profiles and substrate utilization patterns (BIOLOG ECO plates) were measured to examine the effects of deintensification on the structure and diversity of soil microbial communities. Principle component analyses of PLFA and BIOLOG data showed that the microbial community structure diverged among the soils of the six systems.Lower microbial diversity was found in lowly managed ecosystem than that in intensive and moderately managed agroecosystems, and both fungal contribution to the total identified PLFAs and the ratio of microbial biomass C/N increased along with agricultural deintensification. Significantly higher ratios of C/N (P ＜ 0.05) were found in the WO and SU systems, and for fungal/bacterial PLFAs in the WO system (P ＜ 0.05). There were also significant decreases (P ＜ 0.05)along with agricultural deintensification for contributions of total bacterial and gram positive (G+) bacterial PLFAs.Agricultural deintensification could facilitate the development of microbial communities that favor soil fungi over bacteria.

Development of a Wireless Unified-Maintenance System for the Structural Health Monitoring of Civil Structures.

Science.gov (United States)

Heo, Gwanghee; Son, Byungjik; Kim, Chunggil; Jeon, Seunggon; Jeon, Joonryong

2018-05-09

A disaster preventive structural health monitoring (SHM) system needs to be equipped with the following abilities: First, it should be able to simultaneously measure diverse types of data (e.g., displacement, velocity, acceleration, strain, load, temperature, humidity, etc.) for accurate diagnosis. Second, it also requires standalone power supply to guarantee its immediate response in crisis (e.g., sudden interruption of normal AC power in disaster situations). Furthermore, it should be capable of prompt processing and realtime wireless communication of a huge amount of data. Therefore, this study is aimed at developing a wireless unified-maintenance system (WUMS) that would satisfy all the requirements for a disaster preventive SHM system of civil structures. The WUMS is designed to measure diverse types of structural responses in realtime based on wireless communication, allowing users to selectively use WiFi RF band and finally working in standalone mode by means of the field-programmable gate array (FPGA) technology. To verify its performance, the following tests were performed: (i) A test to see how far communication is possible in open field, (ii) a test on a shaker to see how accurate responses are, (iii) a modal test on a bridge to see how exactly characteristic real-time dynamic responses are of structures. The test results proved that the WUMS was able to secure stable communication far up to nearly 800 m away by acquiring wireless responses in realtime accurately, when compared to the displacement and acceleration responses which were acquired through wired communication. The analysis of dynamic characteristics also showed that the wireless acceleration responses in real-time represented satisfactorily the dynamic properties of structures. Therefore, the WUMS is proved valid as a SHM, and its outstanding performance is also proven.

[Community structure and diversity of culturable moderate halophilic bacteria isolated from Qrhan salt lake on Qinghai-Tibet Plateau].

Science.gov (United States)

Shen, Shuo

2017-04-04

I studied the community structure and diversity of culturable moderate halophilic bacteria isolated from Qrhan Salt Lake. I isolated and cultured the moderate halophilic bacteria on different selective media. After the 16S rRNA gene sequences was amplified and measured, I constructed the phylogenic tree, analyzed the community structure and calculated the diversity indexes according to the 16S rRNA gene information. A total of 421 moderate halophilic bacteria were isolated from water and mud samples in Qrhan Salt Lake. The 16S rRNA gene information showed that 4 potential novel species belonged to the family Bacillaceae. Eighty-three model strains belonged to 3 phylurms 6 families 16 genus. Among them, Bacillus sp., Oceanobacillus sp. and Halomonas sp. were dominant species. Diversity analysis showed that the diversity of strains isolated from water sample was higher than that from mud sample, but the dominance degree of strains isolated from mud sample was higher than that from water sample. The genetic diversity of moderate halophilic bacteria isolated from Qrhan Salt Lake was abundant. Also, there were dominant and novel species of culturable moderate halophilic bacteria in this lake.

Structure of Vocational Interests for Diverse Groups on the 2005 Strong Interest Inventory

Science.gov (United States)

Kantamneni, Neeta; Fouad, Nadya

2011-01-01

This study was designed to examine the structure of vocational interests in a diverse sample of individuals who completed the 2005 revision of the Strong Interest Inventory. We examined the fit of three racial/ethnic groups (African American, Caucasian, and Latino/a), both genders, and three levels of professional status (GRS participant, student,…

Arthropod diversity and assemblage structure response to deforestation and desertification in the Sahel of western Senegal

Directory of Open Access Journals (Sweden)

Brandon J. Lingbeek

2017-07-01

Full Text Available Drylands are highly vulnerable to desertification and among the most endangered ecosystems. To understand how biodiversity responds to environmental degradation in these fragile ecosystems, we examined whether arthropod, beetle, spider and ant diversity and assemblage structure differed (1 between seasons, (2 among locations (3 between protected areas of tropical dry forest and adjacent communal lands suffering from desertification, as well as (4 how vegetation impacts assemblage structures. We established 12 plots spaced homogenously throughout each protected area and the adjacent communal land at three locations: Beersheba, Bandia and Ngazobil. Within each plot, we measured canopy closure, vegetation height, percent cover of bare ground, leaf litter, grasses and forbs and collected arthropods using pitfall traps during the 2014 dry (May and rainy (September seasons. We collected 123,705 arthropods representing 733 morphospecies, 10,849 beetles representing 216 morphospecies, 4969 spiders representing 91 morphospecies and 59,183 ants representing 45 morphospecies. Results showed greater arthropod and beetle diversities (P = 0.002–0.040 in the rainy season, no difference in diversity among locations for any taxonomic group and a difference (P ≤ 0.001 in diversity for all taxa between protected areas and communal lands. Assemblage structures of all taxa responded (P = 0.001 to vegetation characteristics, differed (P = 0.015–0.045 between seasons and, with a few exceptions, locations and fragments. Our results illustrate the importance of a multi-taxa approach in understanding biodiversity response to anthropogenic disturbances as well as the value of protected areas in preserving biodiversity of the Sahel.

Propranolol in Treatment of Huge and Complicated Infantile Hemangiomas in Egyptian Children

OpenAIRE

Hassan, Basheir A.; Shreef, Khalid S.

2014-01-01

Background. Infantile hemangiomas (IHs) are the most common benign tumours of infancy. Propranolol has recently been reported to be a highly effective treatment for IHs. This study aimed to evaluate the efficacy and side effects of propranolol for treatment of complicated cases of IHs. Patients and Methods. This prospective clinical study included 30 children with huge or complicated IHs; their ages ranged from 2 months to 1 year. They were treated by oral propranolol. Treatment outcomes were...

Molecular Diversity and Population Structure of a Worldwide Collection of Cultivated Tetraploid Alfalfa (Medicago sativa subsp. sativa L.) Germplasm as Revealed by Microsatellite Markers.

Science.gov (United States)

Qiang, Haiping; Chen, Zhihong; Zhang, Zhengli; Wang, Xuemin; Gao, Hongwen; Wang, Zan

2015-01-01

Information on genetic diversity and population structure of a tetraploid alfalfa collection might be valuable in effective use of the genetic resources. A set of 336 worldwide genotypes of tetraploid alfalfa (Medicago sativa subsp. sativa L.) was genotyped using 85 genome-wide distributed SSR markers to reveal the genetic diversity and population structure in the alfalfa. Genetic diversity analysis identified a total of 1056 alleles across 85 marker loci. The average expected heterozygosity and polymorphism information content values were 0.677 and 0.638, respectively, showing high levels of genetic diversity in the cultivated tetraploid alfalfa germplasm. Comparison of genetic characteristics across chromosomes indicated regions of chromosomes 2 and 3 had the highest genetic diversity. A higher genetic diversity was detected in alfalfa landraces than that of wild materials and cultivars. Two populations were identified by the model-based population structure, principal coordinate and neighbor-joining analyses, corresponding to China and other parts of the world. However, lack of strictly correlation between clustering and geographic origins suggested extensive germplasm exchanges of alfalfa germplasm across diverse geographic regions. The quantitative analysis of the genetic diversity and population structure in this study could be useful for genetic and genomic analysis and utilization of the genetic variation in alfalfa breeding.

Exploring the determinants of phylogenetic diversity and assemblage structure in conifers across temporal, spatial, and taxonomic scales

DEFF Research Database (Denmark)

Eiserhardt, Wolf L.; Borchsenius, Finn; Sandel, Brody Steven

-environmental models are important elements in this framework. Here, we integrate both types of data in order to explore the determinants of forest tree diversity using the conifers as a model group. Conifers are an old, diverse (ca. 650 spp. in 6 families) and widespread group of woody plants of high ecological...... and economic importance. They are better studied than most other globally distributed groups of forest trees, allowing integrative studies with high phylogenetic and spatial resolution. We analyse phylogenetic diversity, assemblage structure, and diversification rates for regional conifer assemblages...

Octopus vulgaris (Cuvier, 1797) in the Mediterranean Sea: Genetic Diversity and Population Structure.

Science.gov (United States)

De Luca, Daniele; Catanese, Gaetano; Procaccini, Gabriele; Fiorito, Graziano

2016-01-01

The common octopus, Octopus vulgaris Cuvier 1797, is a largely exploited cephalopod species in the Mediterranean Sea and the Atlantic Ocean, as well as along the coasts of Africa, Brazil and Japan, where its taxonomic identity is still debated. The assessment of its genetic structure is a pressing need to correctly manage the resource and to avoid overfishing and collapsing of local stocks. Here we analysed genetic variation and population structure of O. vulgaris using thirteen microsatellite loci in seven sampling localities from the Mediterranean Sea and one from the Atlantic Ocean. We also used a DNA barcoding approach by COI gene fragment to understand the phylogenetic relationships among the specimens here investigated and the ones whose sequences are available in literature. Our results reveal high levels of allelic richness and moderate heterozygosity in all samples investigated, and a pronounced differentiation of the Atlantic and Sicilian specimens. This latter aspect seems to support the isolation of the biota within the Strait of Messina. A certain degree of differentiation was detected among the other geographic samples within the Mediterranean Sea, which is more compatible with an island model than isolation by distance. The occurrence of null alleles affected more genetic diversity indices than population structure estimations. This study provides new insights about the genetic diversity and structure of O. vulgaris in the area of interest, which can be used as guidelines for a fisheries management perspective.

Modeling microbial community structure and functional diversity across time and space.

Science.gov (United States)

Larsen, Peter E; Gibbons, Sean M; Gilbert, Jack A

2012-07-01

Microbial communities exhibit exquisitely complex structure. Many aspects of this complexity, from the number of species to the total number of interactions, are currently very difficult to examine directly. However, extraordinary efforts are being made to make these systems accessible to scientific investigation. While recent advances in high-throughput sequencing technologies have improved accessibility to the taxonomic and functional diversity of complex communities, monitoring the dynamics of these systems over time and space - using appropriate experimental design - is still expensive. Fortunately, modeling can be used as a lens to focus low-resolution observations of community dynamics to enable mathematical abstractions of functional and taxonomic dynamics across space and time. Here, we review the approaches for modeling bacterial diversity at both the very large and the very small scales at which microbial systems interact with their environments. We show that modeling can help to connect biogeochemical processes to specific microbial metabolic pathways. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Effects of Predation by Protists on Prokaryotic Community Function, Structure, and Diversity in Anaerobic Granular Sludge.

Science.gov (United States)

Hirakata, Yuga; Oshiki, Mamoru; Kuroda, Kyohei; Hatamoto, Masashi; Kubota, Kengo; Yamaguchi, Takashi; Harada, Hideki; Araki, Nobuo

2016-09-29

Predation by protists is top-down pressure that regulates prokaryotic abundance, community function, structure, and diversity in natural and artificial ecosystems. Although the effects of predation by protists have been studied in aerobic ecosystems, they are poorly understood in anoxic environments. We herein studied the influence of predation by Metopus and Caenomorpha ciliates-ciliates frequently found in anoxic ecosystems-on prokaryotic community function, structure, and diversity. Metopus and Caenomorpha ciliates were cocultivated with prokaryotic assemblages (i.e., anaerobic granular sludge) in an up-flow anaerobic sludge blanket (UASB) reactor for 171 d. Predation by these ciliates increased the methanogenic activities of granular sludge, which constituted 155% of those found in a UASB reactor without the ciliates (i.e., control reactor). Sequencing of 16S rRNA gene amplicons using Illumina MiSeq revealed that the prokaryotic community in the UASB reactor with the ciliates was more diverse than that in the control reactor; 2,885-3,190 and 2,387-2,426 operational taxonomic units (>97% sequence similarities), respectively. The effects of predation by protists in anaerobic engineered systems have mostly been overlooked, and our results show that the influence of predation by protists needs to be examined and considered in the future for a better understanding of prokaryotic community structure and function.

Highly structured genetic diversity of the Mycobacterium tuberculosis population in Djibouti.

Science.gov (United States)

Godreuil, S; Renaud, F; Choisy, M; Depina, J J; Garnotel, E; Morillon, M; Van de Perre, P; Bañuls, A L

2010-07-01

Djibouti is an East African country with a high tuberculosis incidence. This study was conducted over a 2-month period in Djibouti, during which 62 consecutive patients with pulmonary tuberculosis (TB) were included. Genetic characterization of Mycobacterium tuberculosis, using mycobacterial interspersed repetitive-unit variable-number tandem-repeat typing and spoligotyping, was performed. The genetic and phylogenetic analysis revealed only three major families (Central Asian, East African Indian and T). The high diversity and linkage disequilibrium within each family suggest a long period of clonal evolution. A Bayesian approach shows that the phylogenetic structure observed in our sample of 62 isolates is very likely to be representative of the phylogenetic structure of the M. tuberculosis population in the total number of TB cases.

Sequence-Dependent Self-Assembly and Structural Diversity of Islet Amyloid Polypeptide-Derived β-Sheet Fibrils

International Nuclear Information System (INIS)

Wang, Shih-Ting; Lin, Yiyang; Spencer, Ryan K.; Thomas, Michael R.; Nguyen, Andy I.

2017-01-01

Determining the structural origins of amyloid fibrillation is essential for understanding both the pathology of amyloidosis and the rational design of inhibitors to prevent or reverse amyloid formation. In this work, the decisive roles of peptide structures on amyloid self-assembly and morphological diversity were investigated by the design of eight amyloidogenic peptides derived from islet amyloid polypeptide. Among the segments, two distinct morphologies were highlighted in the form of twisted and planar (untwisted) ribbons with varied diameters, thicknesses, and lengths. In particular, transformation of amyloid fibrils from twisted ribbons into untwisted structures was triggered by substitution of the C-terminal serine with threonine, where the side chain methyl group was responsible for the distinct morphological change. This effect was confirmed following serine substitution with alanine and valine and was ascribed to the restriction of intersheet torsional strain through the increased hydrophobic interactions and hydrogen bonding. We also studied the variation of fibril morphology (i.e., association and helicity) and peptide aggregation propensity by increasing the hydrophobicity of the peptide side group, capping the N-terminus, and extending sequence length. Lastly, we anticipate that our insights into sequence-dependent fibrillation and morphological diversity will shed light on the structural interpretation of amyloidogenesis and development of structure-specific imaging agents and aggregation inhibitors.

Critical diversity: Divided or united states of social coordination.

Directory of Open Access Journals (Sweden)

Mengsen Zhang

Full Text Available Much of our knowledge of coordination comes from studies of simple, dyadic systems or systems containing large numbers of components. The huge gap 'in between' is seldom addressed, empirically or theoretically. We introduce a new paradigm to study the coordination dynamics of such intermediate-sized ensembles with the goal of identifying key mechanisms of interaction. Rhythmic coordination was studied in ensembles of eight people, with differences in movement frequency ('diversity' manipulated within the ensemble. Quantitative change in diversity led to qualitative changes in coordination, a critical value separating régimes of integration and segregation between groups. Metastable and multifrequency coordination between participants enabled communication across segregated groups within the ensemble, without destroying overall order. These novel findings reveal key factors underlying coordination in ensemble sizes previously considered too complicated or 'messy' for systematic study and supply future theoretical/computational models with new empirical checkpoints.

Cd(II)-coordination polymers based on tetracarboxylic acid and diverse bis(imidazole) ligands: Synthesis, structural diversity and photoluminescence properties

Energy Technology Data Exchange (ETDEWEB)

Arıcı, Mürsel, E-mail: marici@ogu.edu.tr [Department of Chemistry, Faculty of Arts and Sciences, Eskişehir Osmangazi University, 26480 Eskişehir (Turkey); Yeşilel, Okan Zafer [Department of Chemistry, Faculty of Arts and Sciences, Eskişehir Osmangazi University, 26480 Eskişehir (Turkey); Taş, Murat [Department of Science Education, Education Faculty, Ondokuz Mayıs University, 55139 Samsun (Turkey)

2017-01-15

Three new Cd(II)-coordination polymers, namely, ([Cd{sub 2}(μ{sub 6}-ao{sub 2}btc)(μ-1,5-bipe){sub 2}]·2H{sub 2}O){sub n} (1), ([Cd{sub 2}(μ{sub 6}-ao{sub 2}btc)(μ-1,4-bix){sub 2}]{sub n}·2DMF) (2) and ([Cd{sub 2}(μ{sub 8}-abtc)(μ-1,4-betix)]·DMF·H{sub 2}O){sub n} (3) (ao{sub 2}btc=di-oxygenated form of 3,3′,5,5′-azobenzenetetracarboxylate, 1,5-bipe: 1,5-bis(imidazol-1yl)pentane, 1,4-bix=1,4-bis(imidazol-1ylmethyl)benzene, 1,4-betix=1,4-bis(2-ethylimidazol-1ylmethyl)benzene) were synthesized with 3,3′,5,5′-azobenzenetetracarboxylic acid and flexible, semi-flexible and semi-flexible substituted bis(imidazole) linkers. They were characterized by IR spectroscopy, elemental analysis, single-crystal X-ray diffraction, powder X-ray diffractions (PXRD) and thermal analyses (TG/DTA). Complexes 1–3 exhibited structural diversities depending on flexible, semi-flexible and semi-flexible substituted bis(imidazole) ligands. Complex 1 was 2D structure with 3,6L18 topology. Complex 2 had a 3D pillar-layered framework with the rare sqc27 topology. When semi-flexible substituted bis(imidazole) linker was used, 3D framework of complex 3 was obtained with the paddlewheel Cd{sub 2}(CO{sub 2}){sub 4}-type binuclear SBU. Moreover, thermal and photoluminescence properties of the complexes were determined in detailed. - Graphical abstract: In this study, three novel Cd(II)-coordination polymers were synthesized with 3,3′,5,5′-azobenzenetetracarboxylic acid and flexible, semi-flexible and semi-flexible substituted bis(imidazole) linkers. They were characterized by IR spectroscopy, elemental analysis, single-crystal X-ray diffraction, powder X-ray diffractions (PXRD) and thermal analyses (TG/DTA). Complexes 1–3 exhibited structural diversities depending on flexible, semi-flexible and semi-flexible substituted bis(imidazole) ligands. Complex 1 was 2D structure with 3,6L18 topology. Complex 2 had a 3D pillar-layered framework with the rare sqc27 topology. When semi

On the huge Lie superalgebra of pseudo superdifferential operators and super KP-hierarchies

International Nuclear Information System (INIS)

Sedra, M.B.

1995-08-01

Lie superalgebraic methods are used to establish a connection between the huge Lie superalgebra Ξ of super (pseudo) differential operators and various super KP-hierarchies. We show in particular that Ξ splits into 5 = 2 x 2 + 1 graded algebras expected to correspond to five classes of super KP-hierarchies generalizing the well-known Manin-Radul and Figueroa O'Farrill-Ramos supersymmetric KP-hierarchies. (author). 10 refs

Structure and phylogenetic diversity of post-fire ectomycorrhizal communities of maritime pine.

Science.gov (United States)

Rincón, A; Santamaría, B P; Ocaña, L; Verdú, M

2014-02-01

Environmental disturbances define the diversity and assemblage of species, affecting the functioning of ecosystems. Fire is a major disturbance of Mediterranean pine forests. Pines are highly dependent on the ectomycorrhizal (EM) fungal symbiosis, which is critical for tree recruitment under primary succession. To determine the effects of time since fire on the structure and recovery of EM fungal communities, we surveyed the young Pinus pinaster regenerate in three sites differing in the elapsed time after the last fire event. Pine roots were collected, and EM fungi characterized by sequencing the internal transcribed spacer (ITS) and the large subunit (LSU) regions of the nuclear ribosomal (nr)-DNA. The effects of the elapsed time after fire on the EM community structure (richness, presence/absence of fungi, phylogenetic diversity) and on soil properties were analysed.Fungal richness decreased with the elapsed time since the fire; although, the phylogenetic diversity of the EM community increased. Soil properties were different depending on the elapsed time after fire and particularly, the organic matter, carbon-to-nitrogen (C/N) ratio, nitrogen and iron significantly correlated with the assemblage of fungal species. Ascomycetes, particularly Tuberaceae and Pezizales, were significantly over-represented on saplings in the burned site. On seedlings, a significant over-representation of Rhizopogonaceae and Atheliaceae was observed in the most recently burned site, while other fungi (i.e. Cortinariaceae) were significantly under-represented. Our results are consistent with the hypothesis that fire can act as a selective agent by printing a phylogenetic signal on the EM fungal communities associated with naturally regenerated pines, pointing out to some groups as potential fire-adapted fungi.

Huge endometrioma mimicking mucinous cystadenoma on MR : A case report

Energy Technology Data Exchange (ETDEWEB)

Hwang, Im Kyung; Kim, Bong Soo; Nam, Kung Sook; Kim, Heung Cheol; Yoo, Yun Sik; Lee, Mee Ran; Hwang, Woo Chul [Hallym University, Chunchon (Korea, Republic of)

2001-12-01

Endometriosis is a relatively common gynecologic disease affecting women during their reproductive years. For its diagnosis, magnetic resonance imaging has been shown to have greater specificity than other modalities. Although lesions may show variable signal intensity due to numerous stages of bleeding, the characteristic finding of endometrioma which distinguishes it from other ovarian cystic masses is relatively high signal intensity on T1-weighted images and heterogeneous signal intensity with prominent shading on 72-weighted images. We report an atypical case involving a huge endometrioma. Because of varying signal intensity on T1- and T2-weighted images and scanty shading on T2-weighted images, the findings were misinterpreted and mucinous cystadenoma was diagnosed.

Clonal diversity and fine-scale genetic structure in a high andean treeline population

Czech Academy of Sciences Publication Activity Database

Peng, Y.; Macek, P.; Macková, Jana; Romoleroux, K.; Hensen, I.

2015-01-01

Roč. 47, č. 1 (2015), s. 59-65 ISSN 0006-3606 Grant - others:GA AV ČR(CZ) IAA601110702; GA MŠk(CZ) LM2010009 Program:IA Institutional support: RVO:60077344 Keywords : AFLP * clonal diversity * clonal propagation * fine-scale genetic structure * Polylepis reticulata * treeline Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.944, year: 2015

Genetic diversity and structure in a collection of tulip cultivars assessed by SNP markers

NARCIS (Netherlands)

Tang, N.; Shahin, A.; Bijman, P.J.J.; Liu, J.; Tuyl, van J.M.; Arens, P.

2013-01-01

Although tulip is one of the most important bulbous crops worldwide, the genetic background of most cultivars is unclear at present. The purposes of this study are to investigate genetic diversity and to identify the genetic structure and relationships among tulip cultivars. A total of 236

Tree Diversity and Structure of Andaman Giant Evergreen Forests, India

Directory of Open Access Journals (Sweden)

M. Rajkumar

2008-12-01

Full Text Available We investigated tree diversity in ‘giant evergreen forest’ of Andaman and Nicobar Islands, which falls within the Indo-Burma hot spot of biodiversity in the world. A one hectare square plot was established in sites Kalapahad (KP and Macarthy Valley (MV of Middle Andamans, in which all trees ≥ 30 cm girth at breast height (gbh were enumerated. Tree diversity totaled 105 species that belonged to 63 genera and 49 families. Site MV harboured ~10% greater species richness than KP. Species diversity indices did not vary much between the two sites. In the two sites, there were 1311 individuals of trees (579 ha-1 in KP and 732 in MV. The stand basal area was nearly equal in both the sites (KP- 45.59 m2 ha-1; MV- 47.93 m2 ha-1. Thirteen tree species (12.38% were strict endemics to Andamans. Ten species recorded are rare to the flora of these islands. The two sites are distinctly dominated by two different plant families; Dipterocarpaceae in KP and Myristicaceae in MV. Most of the species were common to central and lower region of Myanmar and Indian mainland. The forest stand structure exhibited a typical reverse-J shape, but site MV had double the density of stems in the lower tree size class than that of KP. The voluminous dipterocarps contributed more to the total above-ground live biomass. The need to preserve these species- and endemics- rich, fragile island forests, prioritized for biodiversity conservation, is emphasized.

Structure, diversity and environmental role of foraminiferal assemblages from reefal settings of Moorea (Society Islands, French Polynesia)

Science.gov (United States)

Fajemila, Olugbenga; Langer, Martin R.

2015-04-01

Reefal and shallow lagoonal environments around the island Moorea (Society Islands, French Polynesia) offer a spectacular variety of microhabitats providing a multitude niches and ideal settings for rich assemblages of tropical benthic foraminifera. The Society Islands are located near the hotspot of tropical marine diversity and represent a transitional location between the high diversity assemblages of the coral triangle and the low diversity biotas of the eastern Pacific. This area constitutes an important biogeographic link and stepping stone between the eastern and western biotas of the tropical Pacific Ocean. We have analyzed the structure, diversity and composition of benthic foraminiferal assemblages from around Moorea to document the composition, species richness and environmental role of larger and smaller benthic foraminifera from within the lagoonal system, the mangrove habitats and fore-reef sites. Foraminifera are prominent producers of calcium carbonate and contribute significantly to structures in reefal settings of the tropical Pacific. We evaluate the potential of larger symbiont-bearing foraminifera as environmental engineers and apply the FORAM-Index as proxy to assess the conditions around Moorea Island. We also evaluate the role of the Society Islands as stepping stone between biogeographic regions of the Pacific Ocean.

Genetic diversity and population structure analysis of European hexaploid bread wheat (Triticum aestivum L.) varieties.

Science.gov (United States)

Nielsen, Nanna Hellum; Backes, Gunter; Stougaard, Jens; Andersen, Stig Uggerhøj; Jahoor, Ahmed

2014-01-01

Progress in plant breeding is facilitated by accurate information about genetic structure and diversity. Here, Diversity Array Technology (DArT) was used to characterize a population of 94 bread wheat (Triticum aestivum L.) varieties of mainly European origin. In total, 1,849 of 7,000 tested markers were polymorphic and could be used for population structure analysis. Two major subgroups of wheat varieties, GrI and GrII, were identified using the program STRUCTURE, and confirmed by principal component analysis (PCA). These subgroups were largely separated according to origin; GrI comprised varieties from Southern and Eastern Europe, whereas GrII contained mostly modern varieties from Western and Northern Europe. A large proportion of the markers contributing most to the genetic separation of the subgroups were located on chromosome 2D near the Reduced height 8 (Rht8) locus, and PCR-based genotyping suggested that breeding for the Rht8 allele had a major impact on subgroup separation. Consistently, analysis of linkage disequilibrium (LD) suggested that different selective pressures had acted on chromosome 2D in the two subgroups. Our data provides an overview of the allele composition of bread wheat varieties anchored to DArT markers, which will facilitate targeted combination of alleles following DArT-based QTL studies. In addition, the genetic diversity and distance data combined with specific Rht8 genotypes can now be used by breeders to guide selection of crossing parents.

Genetic diversity and population structure analysis of European hexaploid bread wheat (Triticum aestivum L. varieties.

Directory of Open Access Journals (Sweden)

Nanna Hellum Nielsen

Full Text Available Progress in plant breeding is facilitated by accurate information about genetic structure and diversity. Here, Diversity Array Technology (DArT was used to characterize a population of 94 bread wheat (Triticum aestivum L. varieties of mainly European origin. In total, 1,849 of 7,000 tested markers were polymorphic and could be used for population structure analysis. Two major subgroups of wheat varieties, GrI and GrII, were identified using the program STRUCTURE, and confirmed by principal component analysis (PCA. These subgroups were largely separated according to origin; GrI comprised varieties from Southern and Eastern Europe, whereas GrII contained mostly modern varieties from Western and Northern Europe. A large proportion of the markers contributing most to the genetic separation of the subgroups were located on chromosome 2D near the Reduced height 8 (Rht8 locus, and PCR-based genotyping suggested that breeding for the Rht8 allele had a major impact on subgroup separation. Consistently, analysis of linkage disequilibrium (LD suggested that different selective pressures had acted on chromosome 2D in the two subgroups. Our data provides an overview of the allele composition of bread wheat varieties anchored to DArT markers, which will facilitate targeted combination of alleles following DArT-based QTL studies. In addition, the genetic diversity and distance data combined with specific Rht8 genotypes can now be used by breeders to guide selection of crossing parents.

Genetic diversity, phylogeographic structure and effect of selection ...

Indian Academy of Sciences (India)

Abdulhakeem B. Ajibike

2017-12-11

Dec 11, 2017 ... RESEARCH ARTICLE. Genetic diversity, phylogeographic ... chickens as genetic resources towards ensuring food security. Keywords. genetic diversity ... PCR product as template DNA, 3.2 pmol of primer and. 8 μL of Big Dye ...

A unified explanation for the diverse structural deviations reported for adult schizophrenics with disrupted speech.

Science.gov (United States)

Chaika, E

1982-06-01

This paper attempts a unified explanation for the diverse manifestations of deviant speech considered pathognomic for schizophrenia. Examination of the structure of such speech shows that what appear to be diverse errors are really manifestations of two problems: apparently random or erroneous triggering of sounds and words coupled with inappropriate perseverations. These are shown to be different manifestations of the same problem, possibly a schizophrenic dysfunction in neurotransmitters in the brain.. Studies of hemispheric asymetry in schizophrenia, involuntary eyetracking, and the probable action of antipsychotic medication confirm the linguistic data.

Forest structure in low-diversity tropical forests: a study of Hawaiian wet and dry forests.

Science.gov (United States)

Ostertag, Rebecca; Inman-Narahari, Faith; Cordell, Susan; Giardina, Christian P; Sack, Lawren

2014-01-01

The potential influence of diversity on ecosystem structure and function remains a topic of significant debate, especially for tropical forests where diversity can range widely. We used Center for Tropical Forest Science (CTFS) methodology to establish forest dynamics plots in montane wet forest and lowland dry forest on Hawai'i Island. We compared the species diversity, tree density, basal area, biomass, and size class distributions between the two forest types. We then examined these variables across tropical forests within the CTFS network. Consistent with other island forests, the Hawai'i forests were characterized by low species richness and very high relative dominance. The two Hawai'i forests were floristically distinct, yet similar in species richness (15 vs. 21 species) and stem density (3078 vs. 3486/ha). While these forests were selected for their low invasive species cover relative to surrounding forests, both forests averaged 5->50% invasive species cover; ongoing removal will be necessary to reduce or prevent competitive impacts, especially from woody species. The montane wet forest had much larger trees, resulting in eightfold higher basal area and above-ground biomass. Across the CTFS network, the Hawaiian montane wet forest was similar to other tropical forests with respect to diameter distributions, density, and aboveground biomass, while the Hawai'i lowland dry forest was similar in density to tropical forests with much higher diversity. These findings suggest that forest structural variables can be similar across tropical forests independently of species richness. The inclusion of low-diversity Pacific Island forests in the CTFS network provides an ∼80-fold range in species richness (15-1182 species), six-fold variation in mean annual rainfall (835-5272 mm yr(-1)) and 1.8-fold variation in mean annual temperature (16.0-28.4°C). Thus, the Hawaiian forest plots expand the global forest plot network to enable testing of ecological theory for

Forest structure in low-diversity tropical forests: a study of Hawaiian wet and dry forests.

Directory of Open Access Journals (Sweden)

Rebecca Ostertag

Full Text Available The potential influence of diversity on ecosystem structure and function remains a topic of significant debate, especially for tropical forests where diversity can range widely. We used Center for Tropical Forest Science (CTFS methodology to establish forest dynamics plots in montane wet forest and lowland dry forest on Hawai'i Island. We compared the species diversity, tree density, basal area, biomass, and size class distributions between the two forest types. We then examined these variables across tropical forests within the CTFS network. Consistent with other island forests, the Hawai'i forests were characterized by low species richness and very high relative dominance. The two Hawai'i forests were floristically distinct, yet similar in species richness (15 vs. 21 species and stem density (3078 vs. 3486/ha. While these forests were selected for their low invasive species cover relative to surrounding forests, both forests averaged 5->50% invasive species cover; ongoing removal will be necessary to reduce or prevent competitive impacts, especially from woody species. The montane wet forest had much larger trees, resulting in eightfold higher basal area and above-ground biomass. Across the CTFS network, the Hawaiian montane wet forest was similar to other tropical forests with respect to diameter distributions, density, and aboveground biomass, while the Hawai'i lowland dry forest was similar in density to tropical forests with much higher diversity. These findings suggest that forest structural variables can be similar across tropical forests independently of species richness. The inclusion of low-diversity Pacific Island forests in the CTFS network provides an ∼80-fold range in species richness (15-1182 species, six-fold variation in mean annual rainfall (835-5272 mm yr(-1 and 1.8-fold variation in mean annual temperature (16.0-28.4°C. Thus, the Hawaiian forest plots expand the global forest plot network to enable testing of ecological

Two-age silviculture: an innovative tool for enhancing species diversity and vertical structure in Appalachian hardwoods

Science.gov (United States)

Gary W. Miller; Petra B. Wood; Jeffrey V. Nichols; Jeffrey V. Nichols

1995-01-01

Silvicultural practices that promote a two-age stand structure provide an opportunity to maintain diversity of woody species and vertical structure for extended periods of time in Appalachian hardwoods. Data from four two-age stands initiated by deferment cutting in West Virginia are summarized for the first 10 to 15 years after treatment. Results indicated that 15...

Facile construction of structurally diverse thiazolidinedione-derived compounds via divergent stereoselective cascade organocatalysis and their biological exploratory studies.

Science.gov (United States)

Zhang, Yongqiang; Wang, Shengzheng; Wu, Shanchao; Zhu, Shiping; Dong, Guoqiang; Miao, Zhenyuan; Yao, Jianzhong; Zhang, Wannian; Sheng, Chunquan; Wang, Wei

2013-06-10

In this article, we present a new approach by merging two powerful synthetic tactics, divergent synthesis and cascade organocatalysis, to create a divergent cascade organocatalysis strategy for the facile construction of new "privileged" substructure-based DOS (pDOS) library. As demonstrated, notably 5 distinct molecular architectures are produced facilely from readily available simple synthons thiazolidinedione and its analogues and α,β-unsaturated aldehydes in 1-3 steps with the powerful strategy. The beauty of the chemistry is highlighted by the efficient formation of structurally new and diverse products from structurally close reactants under the similar reaction conditions. Notably, structurally diverse spiro-thiazolidinediones and -rhodanines are produced from organocatalytic enantioselective 3-component Michael-Michael-aldol cascade reactions of respective thiazolidinediones and rhodanines with enals. Nevertheless, under the similar reaction conditions, reactions of isorhodanine via a Michael-cyclization cascade lead to structurally different fused thiopyranoid scaffolds. This strategy significantly minimizes time- and cost-consuming synthetic works. Furthermore, these molecules possess high structural complexity and functional, stereochemical, and skeletal diversity with similarity to natural scaffolds. In the preliminary biological studies of these molecules, compounds 4f, 8a, and 10a exhibit inhibitory activity against the human breast cancer cells, while compounds 8a, 9a, and 9b display good antifungal activities against Candida albicans and Cryptococcus neoformans. Notably, their structures are different from clinically used triazole antifungal drugs. Therefore, they could serve as good lead compounds for the development of new generation of antifungal agents.

Diversity and population structure of a dominant deciduous tree based on morphological and genetic data

Science.gov (United States)

Zhang, Qin-di; Jia, Rui-Zhi; Meng, Chao; Ti, Chao-Wen; Wang, Yi-Ling

2015-01-01

Knowledge of the genetic diversity and structure of tree species across their geographic ranges is essential for sustainable use and management of forest ecosystems. Acer grosseri Pax., an economically and ecologically important maple species, is mainly distributed in North China. In this study, the genetic diversity and population differentiation of 24 natural populations of this species were evaluated using sequence-related amplified polymorphism markers and morphological characters. The results show that highly significant differences occurred in 32 morphological traits. The coefficient of variation of 34 characters was 18.19 %. Principal component analysis indicated that 18 of 34 traits explained 60.20 % of the total variance. The phenotypic differentiation coefficient (VST) was 36.06 % for all morphological traits. The Shannon–Wiener index of 34 morphological characters was 6.09, while at the population level, it was 1.77. The percentage of polymorphic bands of all studied A. grosseri populations was 82.14 %. Nei's gene diversity (He) and Shannon's information index (I) were 0.35 and 0.50, respectively. Less genetic differentiation was detected among the natural populations (GST = 0.20, ΦST = 0.10). Twenty-four populations of A. grosseri formed two main clusters, which is consistent with morphological cluster analysis. Principal coordinates analysis and STRUCTURE analysis supported the UPGMA-cluster dendrogram. There was no significant correlation between genetic and geographical distances among populations. Both molecular and morphological data suggested that A. grosseri is rich in genetic diversity. The high level of genetic variation within populations could be affected by the biological characters, mating system and lifespan of A. grosseri, whereas the lower genetic diversity among populations could be caused by effective gene exchange, selective pressure from environmental heterogeneity and the species' geographical range. PMID:26311734

Structural basis for diverse N-glycan recognition by HIV-1-neutralizing V1-V2-directed antibody PG16

Energy Technology Data Exchange (ETDEWEB)

Pancera, Marie; Shahzad-ul-Hussan, Syed; Doria-Rose, Nicole A.; McLellan, Jason S.; Bailer, Robert T.; Dai, Kaifan; Loesgen, Sandra; Louder, Mark K.; Staupe, Ryan P.; Yang, Yongping; Zhang, Baoshan; Parks, Robert; Eudailey, Joshua; Lloyd, Krissey E.; Blinn, Julie; Alam, S. Munir; Haynes, Barton F.; Amin, Mohammed N.; Wang, Lai-Xi; Burton, Dennis R.; Koff, Wayne C.; Nabel, Gary J.; Mascola, John R.; Bewley, Carole A; Kwong, Peter D. [NIH; (Scripps); (Duke); (Maryland-MED); (IAVI)

2013-08-05

HIV-1 uses a diverse N-linked-glycan shield to evade recognition by antibody. Select human antibodies, such as the clonally related PG9 and PG16, recognize glycopeptide epitopes in the HIV-1 V1–V2 region and penetrate this shield, but their ability to accommodate diverse glycans is unclear. Here we report the structure of antibody PG16 bound to a scaffolded V1–V2, showing an epitope comprising both high mannose–type and complex-type N-linked glycans. We combined structure, NMR and mutagenesis analyses to characterize glycan recognition by PG9 and PG16. Three PG16-specific residues, arginine, serine and histidine (RSH), were critical for binding sialic acid on complex-type glycans, and introduction of these residues into PG9 produced a chimeric antibody with enhanced HIV-1 neutralization. Although HIV-1–glycan diversity facilitates evasion, antibody somatic diversity can overcome this and can provide clues to guide the design of modified antibodies with enhanced neutralization.

Fish assemblage in a semi-arid Neotropical reservoir: composition, structure and patterns of diversity and abundance.

Science.gov (United States)

Novaes, J L C; Moreira, S I L; Freire, C E C; Sousa, M M O; Costa, R S

2014-05-01

The aim of this study was to analyse the composition, structure and spatial and temporal patterns of diversity and abundance of the ichthyofauna of the Santa Cruz Reservoir in semi-arid Brazil. Data were collected quarterly at eight sampling locations on the reservoir between February 2010 and November 2011 using gillnets from 12- to 70-mm mesh that were left in the water for 12h00min during the night. We evaluated the composition, structure and assemblage descriptors (Shannon-Wiener diversity index and equitability, respectively) and catch per unit effort by the number (CPUEn) and biomass (CPUEb) of the ichthyofauna. The 6,047 individuals (399,211.6 g) captured represented three orders, ten families and 20 species, of which four belonged to introduced species. The family Characidae was the most abundant with a total of 2,772 (45.8%) individuals captured. The species-abundance curve fit the log-normal model. In the spatial analysis of diversity, there were significant differences between sampling sites in the lacustrine and fluvial regions, and the highest values were found in the lacustrine region. In the temporal analysis of diversity, significant differences were also observed between the rainy and dry seasons, and the higher values were found during the dry season. Equitability followed the same spatiotemporal pattern as diversity. The Spearman correlation was significantly negative between diversity and rainfall. A cluster analysis spatially separated the ichthyofauna into two groups: one group formed by sampling sites in the fluvial region and another group formed by the remainder of the points in the lacustrine region. Both the CPUEn and CPUEb values were higher at point 8 (fluvial region) and during the rainy season. A two-way ANOVA showed that the CPUEn and CPUEb values were spatially and temporally significant. We conclude that the spatial and temporal trends of diversity in the Santa Cruz reservoir differ from those of other Brazilian reservoirs but that

Genetic diversity and structure in the Endangered Allen Cays Rock Iguana, Cyclura cychlura inornata

Science.gov (United States)

Aplasca, Andrea C.; Iverson, John B.; Welch, Mark E.; Colosimo, Giuliano

2016-01-01

The Endangered Allen Cays Rock Iguana (Cyclura cychlura inornata) is endemic to the Allen Cays, a tiny cluster of islands in the Bahamas. Naturally occurring populations exist on only two cays (<4 ha each). However, populations of unknown origin were recently discovered on four additional cays. To investigate patterns of genetic variation among these populations, we analyzed nuclear and mitochondrial markers for 268 individuals. Analysis of three mitochondrial gene regions (2,328 bp) and data for eight nuclear microsatellite loci indicated low genetic diversity overall. Estimates of effective population sizes based on multilocus genotypes were also extremely low. Despite low diversity, significant population structuring and variation in genetic diversity measures were detected among cays. Genetic data confirm the source population for an experimentally translocated population while raising concerns regarding other, unauthorized, translocations. Reduced heterozygosity is consistent with a documented historical population decline due to overharvest. This study provides the first range-wide genetic analysis of this subspecies. We suggest strategies to maximize genetic diversity during ongoing recovery including additional translocations to establish assurance populations and additional protective measures for the two remaining natural populations. PMID:26989628

Vegetation structure and species diversity of Wadi Turbah Zahran, Albaha area, southwestern Saudi Arabia

Directory of Open Access Journals (Sweden)

Sami Asir Al-Robai

2017-06-01

Full Text Available The aim of this work was to study the vegetation structure of Wadi Turbah Zahran, Albaha area, Saudi Arabia and some biodiversity indices. Paleontological Statistics (PAST Software Package was used for data analysis. A total of 266 species (201 genera, 71 families were identified and most of the species were herbs (87%. Therophytes (32.7% and Chamaephytes (30.45% were the most prominent groups. Asteraceae family was represented by the highest number of species (15.4% followed by Poaceae (9.4%. Thirty-one families (43.7% were represented by a single genus and species. Thirty-four species (12.8% were common to all sites. The genus Solanum was the most speciose followed by Rumex. Most of the calculated indices showed variations among the sites. Shannon (3.71–4.06, Menhenick (2.271–4.746 and Chao-1 (106–319.6 diversity indices markedly varied among the sites while Simpson values (0.96–0.97 were almost the same. Berger-Parker values revealed the dominance of Hyparrhenia hirta in four sites. Beta diversity values indicated high diversity between site 1 and 4 and less diversity between site 1 and 6.

Genetic diversity and structure in the Endangered Allen Cays Rock Iguana, Cyclura cychlura inornata

Directory of Open Access Journals (Sweden)

Andrea C. Aplasca

2016-03-01

Full Text Available The Endangered Allen Cays Rock Iguana (Cyclura cychlura inornata is endemic to the Allen Cays, a tiny cluster of islands in the Bahamas. Naturally occurring populations exist on only two cays (<4 ha each. However, populations of unknown origin were recently discovered on four additional cays. To investigate patterns of genetic variation among these populations, we analyzed nuclear and mitochondrial markers for 268 individuals. Analysis of three mitochondrial gene regions (2,328 bp and data for eight nuclear microsatellite loci indicated low genetic diversity overall. Estimates of effective population sizes based on multilocus genotypes were also extremely low. Despite low diversity, significant population structuring and variation in genetic diversity measures were detected among cays. Genetic data confirm the source population for an experimentally translocated population while raising concerns regarding other, unauthorized, translocations. Reduced heterozygosity is consistent with a documented historical population decline due to overharvest. This study provides the first range-wide genetic analysis of this subspecies. We suggest strategies to maximize genetic diversity during ongoing recovery including additional translocations to establish assurance populations and additional protective measures for the two remaining natural populations.

Elevational gradients in phylogenetic structure of ant communities reveal the interplay of biotic and abiotic constraints on diversity

DEFF Research Database (Denmark)

Machac, Antonin; Janda, Milan; Dunn, Robert R.

2011-01-01

A central focus of ecology and biogeography is to determine the factors that govern spatial variation in biodiversity. Here, we examined patterns of ant diversity along climatic gradients in three temperate montane systems: Great Smoky Mountains National Park (USA), Chiricahua Mountains (USA......), and Vorarlberg (Austria). To identify the factors which potentially shape these elevational diversity gradients, we analyzed patterns of community phylogenetic structure (i.e. the evolutionary relationships among species coexisting in local communities). We found that species at low-elevation sites tended...... to be evenly dispersed across phylogeny, suggesting that these communities are structured by interspecific competition. In contrast, species occurring at high-elevation sites tended to be more closely related than expected by chance, implying that these communities are structured primarily by environmental...

Effects of Predation by Protists on Prokaryotic Community Function, Structure, and Diversity in Anaerobic Granular Sludge

Science.gov (United States)

Hirakata, Yuga; Oshiki, Mamoru; Kuroda, Kyohei; Hatamoto, Masashi; Kubota, Kengo; Yamaguchi, Takashi; Harada, Hideki; Araki, Nobuo

2016-01-01

Predation by protists is top-down pressure that regulates prokaryotic abundance, community function, structure, and diversity in natural and artificial ecosystems. Although the effects of predation by protists have been studied in aerobic ecosystems, they are poorly understood in anoxic environments. We herein studied the influence of predation by Metopus and Caenomorpha ciliates—ciliates frequently found in anoxic ecosystems—on prokaryotic community function, structure, and diversity. Metopus and Caenomorpha ciliates were cocultivated with prokaryotic assemblages (i.e., anaerobic granular sludge) in an up-flow anaerobic sludge blanket (UASB) reactor for 171 d. Predation by these ciliates increased the methanogenic activities of granular sludge, which constituted 155% of those found in a UASB reactor without the ciliates (i.e., control reactor). Sequencing of 16S rRNA gene amplicons using Illumina MiSeq revealed that the prokaryotic community in the UASB reactor with the ciliates was more diverse than that in the control reactor; 2,885–3,190 and 2,387–2,426 operational taxonomic units (>97% sequence similarities), respectively. The effects of predation by protists in anaerobic engineered systems have mostly been overlooked, and our results show that the influence of predation by protists needs to be examined and considered in the future for a better understanding of prokaryotic community structure and function. PMID:27431197

Electron acceptors for anaerobic oxidation of methane drive microbial community structure and diversity in mud volcanoes.

Science.gov (United States)

Ren, Ge; Ma, Anzhou; Zhang, Yanfen; Deng, Ye; Zheng, Guodong; Zhuang, Xuliang; Zhuang, Guoqiang; Fortin, Danielle

2018-04-06

Mud volcanoes (MVs) emit globally significant quantities of methane into the atmosphere, however, methane cycling in such environments is not yet fully understood, as the roles of microbes and their associated biogeochemical processes have been largely overlooked. Here, we used data from high-throughput sequencing of microbial 16S rRNA gene amplicons from six MVs in the Junggar Basin in northwest China to quantify patterns of diversity and characterize the community structure of archaea and bacteria. We found anaerobic methanotrophs and diverse sulfate- and iron-reducing microbes in all of the samples, and the diversity of both archaeal and bacterial communities was strongly linked to the concentrations of sulfate, iron and nitrate, which could act as electron acceptors in anaerobic oxidation of methane (AOM). The impacts of sulfate/iron/nitrate on AOM in the MVs were verified by microcosm experiments. Further, two representative MVs were selected to explore the microbial interactions based on phylogenetic molecular ecological networks. The sites showed distinct network structures, key species and microbial interactions, with more complex and numerous linkages between methane-cycling microbes and their partners being observed in the iron/sulfate-rich MV. These findings suggest that electron acceptors are important factors driving the structure of microbial communities in these methane-rich environments. © 2018 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

Observation and analysis of electrical structure change and diversity in thunderstorms on the Qinghai-Tibet Plateau

Science.gov (United States)

Li, Yajun; Zhang, Guangshu; Wang, Yanhui; Wu, Bin; Li, Jing

2017-09-01

A comprehensive observation on thunderstorms was conducted in the Qinghai area by using a very high frequency three-dimensional lightning mapping system and Doppler radar. The spatio-temporal evolution of the charge structure of the isolated thunderstorm was analyzed according to the developing process of thunderstorm, and the reasons for the change in charge structure diversity were studied. During the initial developing and mature stages of the thunderstorm, the charge structure was a steady negative dipole polarity, i.e., the negative charge region was above the positive charge region. Furthermore, the total number of flashes was lower during these two stages. During the thunderstorm's dissipation stage, the charge structure was varied and complicated, with a positive dipole, negative dipole, and a tripole charge structure changing and coexisting during this stage. This charge structure diversity was primarily caused by the collision and merging of two local thunderstorm cells, leading to a charge rearrangement and distribution and the formation of a new charge structure. The frequency of the negative cloud-to-ground and intracloud flashes increased sharply in the dissipation stage, reaching a maximum value. The increase in frequency of negative cloud-to-ground was mainly caused by the lower positive charge weakening during the dissipation stage. In addition, the relationship between charging regions and temperature layers was analyzed by combining sounding temperature data with the theory of a non-inductive charging mechanism.

Huge Intracanal lumbar Disc Herniation: a Review of Four Cases

Directory of Open Access Journals (Sweden)

Farzad Omidi-Kashani

2016-01-01

Full Text Available Lumbar disc herniation (LDH is the most common cause of sciatica and only in about 10% of the affected patients, surgical intervention is necessary. The side of the patient (the side of most prominent clinical complaints is usually consistent with the side of imaging (the side with most prominent disc herniation on imaging scans. In this case series, we presented our experience in four cases with huge intracanal LDH that a mismatch between the patient’s side and the imaging’s side was present. In these cases, for deciding to do the operation, the physicians need to rely more on clinical findings, but for deciding the side of discectomy, imaging characteristic (imaging side may be a more important criterion.

Resource diversity and provenance underpin spatial patterns in functional diversity across native and exotic species.

Science.gov (United States)

Méndez, Verónica; Wood, Jamie R; Butler, Simon J

2018-05-01

Functional diversity metrics are increasingly used to augment or replace taxonomic diversity metrics to deliver more mechanistic insights into community structure and function. Metrics used to describe landscape structure and characteristics share many of the same limitations as taxonomy-based metrics, particularly their reliance on anthropogenically defined typologies with little consideration of structure, management, or function. However, the development of alternative metrics to describe landscape characteristics has been limited. Here, we extend the functional diversity framework to characterize landscapes based on the diversity of resources available across habitats present. We then examine the influence of resource diversity and provenance on the functional diversities of native and exotic avian communities in New Zealand. Invasive species are increasingly prevalent and considered a global threat to ecosystem function, but the characteristics of and interactions between sympatric native and exotic communities remain unresolved. Understanding their comparative responses to environmental change and the mechanisms underpinning them is of growing importance in predicting community dynamics and changing ecosystem function. We use (i) matrices of resource use (species) and resource availability (habitats) and (ii) occurrence data for 62 native and 25 exotic species and 19 native and 13 exotic habitats in 2015 10 × 10 km quadrats to examine the relationship between native and exotic avian and landscape functional diversity. The numbers of species in, and functional diversities of, native and exotic communities were positively related. Each community displayed evidence of environmental filtering, but it was significantly stronger for exotic species. Less environmental filtering occurred in landscapes providing a more diverse combination of resources, with resource provenance also an influential factor. Landscape functional diversity explained a greater

Genetic diversity and population structure of Miscanthus sinensis germplasm in China.

Directory of Open Access Journals (Sweden)

Hua Zhao

Full Text Available Miscanthus is a perennial rhizomatous C4 grass native to East Asia. Endowed with great biomass yield, high ligno-cellulose composition, efficient use of radiation, nutrient and water, as well as tolerance to stress, Miscanthus has great potential as an excellent bioenergy crop. Despite of the high potential for biomass production of the allotriploid hybrid M. ×giganteus, derived from M. sacchariflorus and M. sinensis, other options need to be explored to improve the narrow genetic base of M. ×giganteus, and also to exploit other Miscanthus species, including M. sinensis (2n = 2x = 38, as bioenergy crops. In the present study, a large number of 459 M. sinensis accessions, collected from the wide geographical distribution regions in China, were genotyped using 23 SSR markers transferable from Brachypodium distachyon. Genetic diversity and population structure were assessed. High genetic diversity and differentiation of the germplasm were observed, with 115 alleles in total, a polymorphic rate of 0.77, Nei's genetic diversity index (He of 0.32 and polymorphism information content (PIC of 0.26. Clustering of germplasm accessions was primarily in agreement with the natural geographic distribution. AMOVA and genetic distance analyses confirmed the genetic differentiation in the M. sinensis germplasm and it was grouped into five clusters or subpopulations. Significant genetic variation among subpopulations indicated obvious genetic differentiation in the collections, but within-subpopulation variation (83% was substantially greater than the between-subpopulation variation (17%. Considerable phenotypic variation was observed for multiple traits among 300 M. sinensis accessions. Nine SSR markers were found to be associated with heading date and biomass yield. The diverse Chinese M. sinensis germplasm and newly identified SSR markers were proved to be valuable for breeding Miscanthus varieties with desired bioenergy traits.

The growing tree of Archaea: new perspectives on their diversity, evolution and ecology.

Science.gov (United States)

Adam, Panagiotis S; Borrel, Guillaume; Brochier-Armanet, Céline; Gribaldo, Simonetta

2017-11-01

The Archaea occupy a key position in the Tree of Life, and are a major fraction of microbial diversity. Abundant in soils, ocean sediments and the water column, they have crucial roles in processes mediating global carbon and nutrient fluxes. Moreover, they represent an important component of the human microbiome, where their role in health and disease is still unclear. The development of culture-independent sequencing techniques has provided unprecedented access to genomic data from a large number of so far inaccessible archaeal lineages. This is revolutionizing our view of the diversity and metabolic potential of the Archaea in a wide variety of environments, an important step toward understanding their ecological role. The archaeal tree is being rapidly filled up with new branches constituting phyla, classes and orders, generating novel challenges for high-rank systematics, and providing key information for dissecting the origin of this domain, the evolutionary trajectories that have shaped its current diversity, and its relationships with Bacteria and Eukarya. The present picture is that of a huge diversity of the Archaea, which we are only starting to explore.

Diversity and community structure of marine microbes around the Benham Rise underwater plateau, northeastern Philippines.

Science.gov (United States)

Gajigan, Andrian P; Yñiguez, Aletta T; Villanoy, Cesar L; San Diego-McGlone, Maria Lourdes; Jacinto, Gil S; Conaco, Cecilia

2018-01-01

Microbes are central to the structuring and functioning of marine ecosystems. Given the remarkable diversity of the ocean microbiome, uncovering marine microbial taxa remains a fundamental challenge in microbial ecology. However, there has been little effort, thus far, to describe the diversity of marine microorganisms in the region of high marine biodiversity around the Philippines. Here, we present data on the taxonomic diversity of bacteria and archaea in Benham Rise, Philippines, Western Pacific Ocean, using 16S V4 rRNA gene sequencing. The major bacterial and archaeal phyla identified in the Benham Rise are Proteobacteria, Cyanobacteria, Actinobacteria, Bacteroidetes, Marinimicrobia, Thaumarchaeota and, Euryarchaeota. The upper mesopelagic layer exhibited greater microbial diversity and richness compared to surface waters. Vertical zonation of the microbial community is evident and may be attributed to physical stratification of the water column acting as a dispersal barrier. Canonical Correspondence Analysis (CCA) recapitulated previously known associations of taxa and physicochemical parameters in the environment, such as the association of oligotrophic clades with low nutrient surface water and deep water clades that have the capacity to oxidize ammonia or nitrite at the upper mesopelagic layer. These findings provide foundational information on the diversity of marine microbes in Philippine waters. Further studies are warranted to gain a more comprehensive picture of microbial diversity within the region.

Low genetic diversity and strong population structure shaped by anthropogenic habitat fragmentation in a critically endangered primate, Trachypithecus leucocephalus.

Science.gov (United States)

Wang, W; Qiao, Y; Li, S; Pan, W; Yao, M

2017-06-01

Habitat fragmentation may strongly impact population genetic structure and reduce the genetic diversity and viability of small and isolated populations. The white-headed langur (Trachypithecus leucocephalus) is a critically endangered primate species living in a highly fragmented and human-modified habitat in southern China. We examined the population genetic structure and genetic diversity of the species and investigated the environmental and anthropogenic factors that may have shaped its population structure. We used 214 unique multi-locus genotypes from 41 social groups across the main distribution area of T. leucocephalus, and found strong genetic structure and significant genetic differentiation among local populations. Our landscape genetic analyses using a causal modelling framework suggest that a large habitat gap and geographical distance represent the primary landscape elements shaping genetic structure, yet high levels of genetic differentiation also exist between patches separated by a small habitat gap or road. This is the first comprehensive study that has evaluated the population genetic structure and diversity of T. leucocephalus using nuclear markers. Our results indicate strong negative impacts of anthropogenic land modifications and habitat fragmentation on primate genetic connectivity between forest patches. Our analyses suggest that two management units of the species could be defined, and indicate that habitat continuity should be enforced and restored to reduce genetic isolation and enhance population viability.

DNA pyrosequencing evidence for large diversity differences between natural and managed coffee mycorrhizal fungal communities

OpenAIRE

De Beenhouwer , Matthias; Muleta , Diriba; Peeters , Bram; Van Geel , Maarten; Lievens , Bart; Honnay , Olivier

2015-01-01

International audience; Arabica coffee is a major agricultural commodity worldwide, representing 60 % of the world’s coffee production. Arabica coffee is cultivated in more than 36 countries and is a key cash crop for many developing countries. Despite the coffee’s huge economic importance, there is very limited knowledge on the association of arbuscular mycorrhizal fungi with coffee roots. Therefore, we assessed the mycorrhizal diversity and community composition in Arabica coffee (Coffea ar...

Genetic diversity and population structure of common bean ...

African Journals Online (AJOL)

The Ethiopian genetic center is considered to be one of the secondary centers of diversity for the common bean. This study was conducted to characterize the distribution of genetic diversity between and within ecological/geographical regions of Ethiopia. A germplasm sample of 116 landrace accessions was developed, ...

Community diversity, structure and carbon footprint of nematode food web following reforestation on degraded Karst soil.

Science.gov (United States)

Hu, Ning; Li, Hui; Tang, Zheng; Li, Zhongfang; Tian, Jing; Lou, Yilai; Li, Jianwei; Li, Guichun; Hu, Xiaomin

2016-06-17

We examined community diversity, structure and carbon footprint of nematode food web along a chronosequence of T. Sinensis reforestation on degraded Karst. In general, after the reforestation: a serious of diversity parameters and community indices (Shannon-Weinier index (H'), structure index (SI), etc.) were elevated; biomass ratio of fungivores to bacterivores (FFC/BFC), and fungi to bacteria (F/B) were increased, and nematode channel ratio (NCR) were decreased; carbon footprints of all nematode trophic groups, and biomass of bacteria and fungi were increased. Our results indicate that the Karst aboveground vegetation restoration was accompanied with belowground nematode food web development: increasing community complexity, function and fungal dominance in decomposition pathway, and the driving forces included the bottom-up effect (resource control), connectedness of functional groups, as well as soil environments.

Dynamics of soil diazotrophic community structure, diversity, and functioning during the cropping period of cotton (Gossypium hirsutum).

Science.gov (United States)

Rai, Sandhya; Singh, Dileep Kumar; Annapurna, Kannepalli

2015-01-01

The soil sampled at different growth stages along the cropping period of cotton were analyzed using various molecular tools: restriction fragment length polymorphism (RFLP), terminal restriction length polymorphism (T-RFLP), and cloning-sequencing. The cluster analysis of the diazotrophic community structure of early sampled soil (0, 15, and 30 days) was found to be more closely related to each other than the later sampled one. Phylogenetic and diversity analysis of sequences obtained from the first (0 Day; C0) and last soil sample (180 day; C180) confirmed the data. The phylogenetic analysis revealed that C0 was having more unique sequences than C180 (presence of γ-Proteobacteria exclusively in C0). A relatively higher richness of diazotrophic community sequences was observed in C0 (S(ACE) : 30.76; S(Chao1) : 20.94) than C180 (S(ACE) : 18.00; S(Chao1) : 18.00) while the evenness component of Shannon diversity index increased from C0 (0.97) to C180 (1.15). The impact of routine agricultural activities was more evident based on diazotrophic activity (measured by acetylene reduction assay) than its structure and diversity. The nitrogenase activity of C0 (1264.85 ± 35.7 ηmol of ethylene production g(-1) dry soil h(-1) ) was statistically higher when compared to all other values (p structure/diversity and N2 fixation rates. Thus, considerable functional redundancy of nifH was concluded to be existing at the experimental site. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Diversity and population structure of Marine Group A bacteria in the Northeast subarctic Pacific Ocean

OpenAIRE

Allers, Elke; Wright, Jody J; Konwar, Kishori M; Howes, Charles G; Beneze, Erica; Hallam, Steven J; Sullivan, Matthew B

2012-01-01

Marine Group A (MGA) is a candidate phylum of Bacteria that is ubiquitous and abundant in the ocean. Despite being prevalent, the structural and functional properties of MGA populations remain poorly constrained. Here, we quantified MGA diversity and population structure in relation to nutrients and O2 concentrations in the oxygen minimum zone (OMZ) of the Northeast subarctic Pacific Ocean using a combination of catalyzed reporter deposition fluorescence in situ hybridization (CARD-FISH) and ...

Genetic diversity and population structure of leafy kale and Brassica rupestris Raf. in south Italy

DEFF Research Database (Denmark)

Maggioni, Lorenzo; von Bothmer, Roland; Poulsen, Gert

2014-01-01

Local varieties of leafy kales (Brassica oleracea L.) are grown in home gardens in Calabria and Sicily for self-consumption, in the same area where the wild relative Brassica rupestris Raf. also grows. With the use of AFLP markers, comparisons were made of the genetic diversity and population...... structure of ten wild and 22 cultivated populations, as well as of a hybrid population and of four commercial cultivars of different B. oleracea crops. The level of genetic diversity was higher in leafy kales than in wild populations and this diversity was mainly distributed within populations. Wild...... populations remained distinct from cultivated material. Additionally, most wild populations were distinctively isolated from each other. On the other hand, it was not possible to molecularly distinguish even geographically distant leafy kale populations from each other or from different B. oleracea crops...

Population Genetic Structure and Genetic Diversity in Twisted-Jaw Fish, Belodontichthys truncatus Kottelat & Ng, 1999 (Siluriformes: Siluridae, from Mekong Basin

Directory of Open Access Journals (Sweden)

Surapon Yodsiri

2017-01-01

Full Text Available The Mekong River and its tributaries possess the second highest diversity in fish species in the world. However, the fish biodiversity in this river is threatened by several human activities, such as hydropower plant construction. Understanding the genetic diversity and genetic structure of the species is important for natural resource management. Belodontichthys truncatus Kottelat & Ng is endemic to the Mekong River basin and is an important food source for people in this area. In this study, the genetic diversity, genetic structure, and demographic history of the twisted-jaw fish, B. truncatus, were investigated using mitochondrial cytochrome b gene sequences. A total of 124 fish specimens were collected from 10 locations in the Mekong and its tributaries. Relatively high genetic diversity was found in populations of B. truncatus compared to other catfish species in the Mekong River. The genetic structure analysis revealed that a population from the Chi River in Thailand was genetically significantly different from other populations, which is possibly due to the effect of genetic drift. Demographic history analysis indicated that B. truncatus has undergone recent demographic expansion dating back to the end of the Pleistocene glaciation.

[Radical Resection of Huge Gastrointestinal Stromal Tumor of the Stomach Following Neoadjuvant Chemotherapy with lmatinib - ACase Report].

Science.gov (United States)

Hiraki, Yoko; Kato, Hiroaki; Shiraishi, Osamu; Tanaka, Yumiko; Iwama, Mitsuru; Yasuda, Atsushi; Shinkai, Masayuki; Kimura, Yutaka; Imano, Motohiro; Imamoto, Haruhiko; Yasuda, Takushi

2017-11-01

The usefulness and safety of imatinibfor neoadjuvant chemotherapy for resectable gastrointestinal stromal tumor(GIST) has not been established. We reported a case of a huge GIST of the stomach that was safely resected following preoperative imatinibtherapy. A 69-year-old man was hospitalized with abdominal fullness which increased rapidly from a month ago. A CT scan showed a huge tumor containing solid and cystic component which was accompanied by an extra-wall nodule. The tumor was strongly suspected to be originated from the stomach and EUS-FNA revealed GIST. We diagnosed GIST of the stomach and initiated preoperative adjuvant chemotherapy with imatinib because there was a risk for the break of tumor capsule and composite resection of the other organs without prior chemotherapy. After the administration of imatinib4 00 mg/day for 6months, the solid component was decreased in size and its' activity by PET-CT had declined, but the size of the cystic component was not changed and the patient's complaint of fullness was not reduced. Then, after a week cessation of imatinib, we performed surgical removal of the tumor with partial gastrectomy without surgical complication during and after the operation. Imatinibwas resumed 2 weeks later postoperatively and 1 year and 8 months has passed since the operation without recurrence. Neoadjuvant chemotherapy with imatinibhas the potential to become an important therapeutic option for the treatment of huge GISTs.

Divergence Measures as Diversity Indices

OpenAIRE

Abou-Moustafa, Karim T.

2014-01-01

Entropy measures of probability distributions are widely used measures in ecology, biology, genetics, and in other fields, to quantify species diversity of a community. Unfortunately, entropy-based diversity indices, or diversity indices for short, suffer from three problems. First, when computing the diversity for samples withdrawn from communities with different structures, diversity indices can easily yield non-comparable and hard to interpret results. Second, diversity indices impose weig...

Biosynthetic multitasking facilitates thalassospiramide structural diversity in marine bacteria

KAUST Repository

Ross, Avena C.

2013-01-23

Thalassospiramides A and B are immunosuppressant cyclic lipopeptides first reported from the marine α-proteobacterium Thalassospira sp. CNJ-328. We describe here the discovery and characterization of an extended family of 14 new analogues from four Tistrella and Thalassospira isolates. These potent calpain 1 protease inhibitors belong to six structure classes in which the length and composition of the acylpeptide side chain varies extensively. Genomic sequence analysis of the thalassospiramide-producing microbes revealed related, genus-specific biosynthetic loci encoding hybrid nonribosomal peptide synthetase/polyketide synthases consistent with thalassospiramide assembly. The bioinformatics analysis of the gene clusters suggests that structural diversity, which ranges from the 803.4 Da thalassospiramide C to the 1291.7 Da thalassospiramide F, results from a complex sequence of reactions involving amino acid substrate channeling and enzymatic multimodule skipping and iteration. Preliminary biochemical analysis of the N-terminal nonribosomal peptide synthetase module from the Thalassospira TtcA megasynthase supports a biosynthetic model in which in cis amino acid activation competes with in trans activation to increase the range of amino acid substrates incorporated at the N terminus. © 2012 American Chemical Society.

Biosynthetic multitasking facilitates thalassospiramide structural diversity in marine bacteria

KAUST Repository

Ross, Avena C.; Xü , Ying; Lu, Liang; Kersten, Roland D.; Shao, Zongze; Al-Suwailem, Abdulaziz M.; Dorrestein, Pieter C.; Qian, Peiyuan; Moore, Bradley S.

2013-01-01

Thalassospiramides A and B are immunosuppressant cyclic lipopeptides first reported from the marine α-proteobacterium Thalassospira sp. CNJ-328. We describe here the discovery and characterization of an extended family of 14 new analogues from four Tistrella and Thalassospira isolates. These potent calpain 1 protease inhibitors belong to six structure classes in which the length and composition of the acylpeptide side chain varies extensively. Genomic sequence analysis of the thalassospiramide-producing microbes revealed related, genus-specific biosynthetic loci encoding hybrid nonribosomal peptide synthetase/polyketide synthases consistent with thalassospiramide assembly. The bioinformatics analysis of the gene clusters suggests that structural diversity, which ranges from the 803.4 Da thalassospiramide C to the 1291.7 Da thalassospiramide F, results from a complex sequence of reactions involving amino acid substrate channeling and enzymatic multimodule skipping and iteration. Preliminary biochemical analysis of the N-terminal nonribosomal peptide synthetase module from the Thalassospira TtcA megasynthase supports a biosynthetic model in which in cis amino acid activation competes with in trans activation to increase the range of amino acid substrates incorporated at the N terminus. © 2012 American Chemical Society.

Genetic diversity and population structure of Lantana camara in India indicates multiple introductions and gene flow.

Science.gov (United States)

Ray, A; Quader, S

2014-05-01

Lantana camara is a highly invasive plant, which has spread over 60 countries and island groups of Asia, Africa and Australia. In India, it was introduced in the early nineteenth century, since when it has expanded and gradually established itself in almost every available ecosystem. We investigated the genetic diversity and population structure of this plant in India in order to understand its introduction, subsequent range expansion and gene flow. A total of 179 individuals were sequenced at three chloroplast loci and 218 individuals were genotyped for six nuclear microsatellites. Both chloroplasts (nine haplotypes) and microsatellites (83 alleles) showed high genetic diversity. Besides, each type of marker confirmed the presence of private polymorphism. We uncovered low to medium population structure in both markers, and found a faint signal of isolation by distance with microsatellites. Bayesian clustering analyses revealed multiple divergent genetic clusters. Taken together, these findings (i.e. high genetic diversity with private alleles and multiple genetic clusters) suggest that Lantana was introduced multiple times and gradually underwent spatial expansion with recurrent gene flow. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

Metabolic Effects of Berries with Structurally Diverse Anthocyanins

Directory of Open Access Journals (Sweden)

John Overall

2017-02-01

Full Text Available Overconsumption of energy dense foods and sedentary lifestyle are considered as major causes of obesity-associated insulin resistance and abnormal glucose metabolism. Results from both cohort studies and randomized trials suggested that anthocyanins from berries may lower metabolic risks, however these reports are equivocal. The present study was designed to examine effects of six berries with structurally diverse anthocyanin profiles (normalized to 400 µg/g total anthocyanin content on development of metabolic risk factors in the C57BL/6 mouse model of polygenic obesity. Diets supplemented with blackberry (mono-glycosylated cyanidins, black raspberry (acylated mono-glycosylated cyanidins, blackcurrant (mono- and di-glycosylated cyanidins and delphinidins, maqui berry (di-glycosylated delphinidins, Concord grape (acylated mono-glycosylated delphinidins and petunidins, and blueberry (mono-glycosylated delphinidins, malvidins, and petunidins showed a prominent discrepancy between biological activities of delphinidin/malvidin-versus cyanidin-type anthocyanins that could be explained by differences in their structure and metabolism in the gut. Consumption of berries also resulted in a strong shift in the gastrointestinal bacterial communities towards obligate anaerobes that correlated with decrease in the gastrointestinal luminal oxygen and oxidative stress. Further work is needed to understand mechanisms that lead to nearly anoxic conditions in the gut lumens, including the relative contributions of host, diet and/or microbial oxidative activity, and their implication to human health.

Surgical resection of a huge cemento-ossifying fibroma in skull base by intraoral approach.

Science.gov (United States)

Cheng, Xiao-Bing; Li, Yun-Peng; Lei, De-Lin; Li, Xiao-Dong; Tian, Lei

2011-03-01

Cemento-ossifying fibroma, also known as ossifying fibroma, usually occurs in the mandible and less commonly in the maxilla. The huge example in the skull base is even rare. We present a case of a huge cemento-ossifying fibroma arising below the skull base of a 30-year-old woman patient. Radiologic investigations showed a giant, lobulated, heterogeneous calcified hard tissue mass, which is well circumscribed and is a mixture of radiolucent and radiopaque, situated at the rear of the right maxilla to the middle skull base. The tumor expands into the right maxillary sinus and the orbital cavity, fusing with the right maxilla at the maxillary tuberosity and blocking the bilateral choanas, which caused marked proptosis and blurred vision. The tumor was resected successfully by intraoral approach, and pathologic examination confirmed the lesion to be a cemento-ossifying fibroma. This case demonstrates that cemento-ossifying fibroma in the maxilla, not like in the mandible, may appear more aggressive because the extensive growth is unimpeded by anatomic obstacles and that the intraoral approach can be used to excise the tumor in the skull base.

Genetic diversity and population structure of leafy kale and Brassica rupestris Raf. in south Italy.

Science.gov (United States)

Maggioni, Lorenzo; von Bothmer, Roland; Poulsen, Gert; Branca, Ferdinando; Bagger Jørgensen, Rikke

2014-12-01

Local varieties of leafy kales (Brassica oleracea L.) are grown in home gardens in Calabria and Sicily for self-consumption, in the same area where the wild relative Brassica rupestris Raf. also grows. With the use of AFLP markers, comparisons were made of the genetic diversity and population structure of ten wild and 22 cultivated populations, as well as of a hybrid population and of four commercial cultivars of different B. oleracea crops. The level of genetic diversity was higher in leafy kales than in wild populations and this diversity was mainly distributed within populations. Wild populations remained distinct from cultivated material. Additionally, most wild populations were distinctively isolated from each other. On the other hand, it was not possible to molecularly distinguish even geographically distant leafy kale populations from each other or from different B. oleracea crops. It was possible to detect inter-crossing between leafy kales and B. rupestris. Findings from this study illustrate the existing level of genetic diversity in the B. oleracea gene pool. Individual populations (either wild or leafy kales) with higher levels of genetic diversity have been identified and suggestions are given for an informed conservation strategy. Domestication hypotheses are also discussed. © 2015 The Authors.

Reconstruction of juxta-articular huge defects of distal femur with vascularized fibular bone graft and Ilizarov's distraction osteogenesis.

Science.gov (United States)

Lai, Davy; Chen, Chuan-Mu; Chiu, Fang-Yao; Chang, Ming-Chau; Chen, Tain-Hsiung

2007-01-01

We evaluate the effect of reconstructing huge defects (mean, 15.8 cm) of the distal femur with Ilizarov's distraction osteogenesis and free twin-barreled vascularized fibular bone graft (TVFG). We retrospectively reviewed a consecutive series of five patients who had cases of distal femoral fractures with huge defects and infection that were treated by the Ilizarov's distraction osteogenesis. After radical debridement, two of the five cases had free TVFG and monolocal distraction osteogenesis, and another two cases had multilocal distraction osteogenesis with knee fusion because of loss of the joint congruity. The other case with floating knee injury had bilocal distraction osteogenesis and a preserved knee joint. The mean defect of distal femur was 15.8 cm (range, 14-18 cm) in length. The mean length of distraction osteogenesis by Ilizarov's apparatus was 8.2 cm. The mean length of TVFG was 8 cm. The average duration from application of Ilizarov's apparatus to achievement of bony union was 10.2 months (range, 8-13 months). At the end of the follow-up, ranges of motion of three knees were 0 to 45 degrees, 0 to 60 degrees, and 0 to 90 degrees. Two cases had knee arthrodesis with bony fusion because of loss of the joint congruity. There were no leg length discrepancies in all five patients. In addition, three patients had pin tract infections and one case had a 10 degree varus deformity of the femur. Juxta-articular huge defect (>10 cm) of distal femur remains a challenge to orthopedic surgeons. Ilizarov's technique provides the capability to maintain stability, eradicate infection, restore leg length, and to perform adjuvant reconstructive procedure easily. In this study, we found that combining Ilizarov's distraction osteogenesis with TVFG results in improved patient outcome for patients with injuries such as supracondylar or intercondylar infected fractures or nonunion of distal femur with huge bone defect.

Analysis of Genetic Diversity and Structure Pattern of Indigofera Pseudotinctoria in Karst Habitats of the Wushan Mountains Using AFLP Markers.

Science.gov (United States)

Fan, Yan; Zhang, Chenglin; Wu, Wendan; He, Wei; Zhang, Li; Ma, Xiao

2017-10-16

Indigofera pseudotinctoria Mats is an agronomically and economically important perennial legume shrub with a high forage yield, protein content and strong adaptability, which is subject to natural habitat fragmentation and serious human disturbance. Until now, our knowledge of the genetic relationships and intraspecific genetic diversity for its wild collections is still poor, especially at small spatial scales. Here amplified fragment length polymorphism (AFLP) technology was employed for analysis of genetic diversity, differentiation, and structure of 364 genotypes of I. pseudotinctoria from 15 natural locations in Wushan Montain, a highly structured mountain with typical karst landforms in Southwest China. We also tested whether eco-climate factors has affected genetic structure by correlating genetic diversity with habitat features. A total of 515 distinctly scoreable bands were generated, and 324 of them were polymorphic. The polymorphic information content (PIC) ranged from 0.694 to 0.890 with an average of 0.789 per primer pair. On species level, Nei's gene diversity ( H j ), the Bayesian genetic diversity index ( H B ) and the Shannon information index ( I ) were 0.2465, 0.2363 and 0.3772, respectively. The high differentiation among all sampling sites was detected ( F ST = 0.2217, G ST = 0.1746, G' ST = 0.2060, θ B = 0.1844), and instead, gene flow among accessions ( N m = 1.1819) was restricted. The population genetic structure resolved by the UPGMA tree, principal coordinate analysis, and Bayesian-based cluster analyses irrefutably grouped all accessions into two distinct clusters, i.e., lowland and highland groups. The population genetic structure resolved by the UPGMA tree, principal coordinate analysis, and Bayesian-based cluster analyses irrefutably grouped all accessions into two distinct clusters, i.e., lowland and highland groups. This structure pattern may indicate joint effects by the neutral evolution and natural selection. Restricted N m was

The role of historical and contemporary processes on phylogeographic structure and genetic diversity in the Northern Cardinal, Cardinalis cardinalis

Directory of Open Access Journals (Sweden)

Navarro-Sigüenza Adolfo G

2011-05-01

Full Text Available Abstract Background Earth history events such as climate change are believed to have played a major role in shaping patterns of genetic structure and diversity in species. However, there is a lag between the time of historical events and the collection of present-day samples that are used to infer contemporary population structure. During this lag phase contemporary processes such as dispersal or non-random mating can erase or reinforce population differences generated by historical events. In this study we evaluate the role of both historical and contemporary processes on the phylogeography of a widespread North American songbird, the Northern Cardinal, Cardinalis cardinalis. Results Phylogenetic analysis revealed deep mtDNA structure with six lineages across the species' range. Ecological niche models supported the same geographic breaks revealed by the mtDNA. A paleoecological niche model for the Last Glacial Maximum indicated that cardinals underwent a dramatic range reduction in eastern North America, whereas their ranges were more stable in México. In eastern North America cardinals expanded out of glacial refugia, but we found no signature of decreased genetic diversity in areas colonized after the Last Glacial Maximum. Present-day demographic data suggested that population growth across the expansion cline is positively correlated with latitude. We propose that there was no loss of genetic diversity in areas colonized after the Last Glacial Maximum because recent high-levels of gene flow across the region have homogenized genetic diversity in eastern North America. Conclusion We show that both deep historical events as well as demographic processes that occurred following these events are critical in shaping genetic pattern and diversity in C. cardinalis. The general implication of our results is that patterns of genetic diversity are best understood when information on species history, ecology, and demography are considered

The efficacy of stereotactic body radiation therapy on huge hepatocellular carcinoma unsuitable for other local modalities

International Nuclear Information System (INIS)

Que, Jenny Y; Lin, Li-Ching; Lin, Kuei-Li; Lin, Chia-Hui; Lin, Yu-Wei; Yang, Ching-Chieh

2014-01-01

To evaluate the safety and efficacy of Cyberknife stereotactic body radiation therapy (SBRT) and its effect on survival in patients with unresectable huge hepatocellular carcinoma (HCC) unsuitable of other standard treatment option. Between 2009 and 2011, 22 patients with unresectable huge HCC (≧10 cm) were treated with SBRT. dose ranged from 26 Gy to 40 Gy in five fractions. Overall survival (OS) and disease-progression free survival (DPFS) were determined by Kaplan-Meier analysis. Tumor response and toxicities were also assessed. After a median follow-up of 11.5 month (range 2–46 months). The objective response rate was achieved in 86.3% (complete response (CR): 22.7% and partial response (PR): 63.6%). The 1-yr. local control rate was 55.56%. The 1-year OS was 50% and median survival was 11 months (range 2–46 months). In univariate analysis, Child-Pugh stage (p = 0.0056) and SBRT dose (p = 0.0017) were significant factors for survival. However, in multivariate analysis, SBRT dose (p = 0.0072) was the most significant factor, while Child-Pugh stage of borderline significance. (p = 0.0514). Acute toxicities were mild and well tolerated. This study showed that SBRT can be delivered safely to huge HCC and achieved a substantial tumor regression and survival. The results suggest this technique should be considered a salvage treatment. However, local and regional recurrence remain the major cause of failure. Further studies of combination of SBRT and other treatment modalities may be reasonable

Distributed and parallel approach for handle and perform huge datasets

Science.gov (United States)

Konopko, Joanna

2015-12-01

Big Data refers to the dynamic, large and disparate volumes of data comes from many different sources (tools, machines, sensors, mobile devices) uncorrelated with each others. It requires new, innovative and scalable technology to collect, host and analytically process the vast amount of data. Proper architecture of the system that perform huge data sets is needed. In this paper, the comparison of distributed and parallel system architecture is presented on the example of MapReduce (MR) Hadoop platform and parallel database platform (DBMS). This paper also analyzes the problem of performing and handling valuable information from petabytes of data. The both paradigms: MapReduce and parallel DBMS are described and compared. The hybrid architecture approach is also proposed and could be used to solve the analyzed problem of storing and processing Big Data.

Fine structure of Tibetan kefir grains and their yeast distribution, diversity, and shift.

Directory of Open Access Journals (Sweden)

Man Lu

Full Text Available Tibetan kefir grains (TKGs, a kind of natural starter for fermented milk in Tibet, China, host various microorganisms of lactic acid bacteria, yeasts, and occasionally acetic acid bacteria in a polysaccharide/protein matrix. In the present study, the fine structure of TKGs was studied to shed light on this unusual symbiosis with stereomicroscopy and thin sections. The results reveal that TKGs consist of numerous small grain units, which are characterized by a hollow globular structure with a diameter between 2.0 and 9.0 mm and a wall thickness of approximately 200 µm. A polyhedron-like net structure, formed mainly by the bacteria, was observed in the wall of the grain units, which has not been reported previously to our knowledge. Towards the inside of the grain unit, the polyhedron-like net structures became gradually larger in diameter and fewer in number. Such fine structures may play a crucial role in the stability of the grains. Subsequently, the distribution, diversity, and shift of yeasts in TKGs were investigated based on thin section, scanning electron microscopy, cloning and sequencing of D1/D2 of the 26S rRNA gene, real-time quantitative PCR, and in situ hybridization with specific fluorescence-labeled oligonucleotide probes. These show that (i yeasts appear to localize on the outer surface of the grains and grow normally together to form colonies embedded in the bacterial community; (ii the diversity of yeasts is relatively low on genus level with three dominant species--Saccharomyces cerevisiae, Kluyveromyces marxianus, and Yarrowia lipolytica; (iii S. cerevisiae is the stable predominant yeast species, while the composition of Kluyveromyces and Yarrowia are subject to change over time. Our results indicate that TKGs are relatively stable in structure, and culture conditions to some extent shape the microbial community and interaction in kefir grains. These findings pave the way for further study of the specific symbiotic

Fine Structure of Tibetan Kefir Grains and Their Yeast Distribution, Diversity, and Shift

Science.gov (United States)

Lu, Man; Wang, Xingxing; Sun, Guowei; Qin, Bing; Xiao, Jinzhou; Yan, Shuling; Pan, Yingjie; Wang, Yongjie

2014-01-01

Tibetan kefir grains (TKGs), a kind of natural starter for fermented milk in Tibet, China, host various microorganisms of lactic acid bacteria, yeasts, and occasionally acetic acid bacteria in a polysaccharide/protein matrix. In the present study, the fine structure of TKGs was studied to shed light on this unusual symbiosis with stereomicroscopy and thin sections. The results reveal that TKGs consist of numerous small grain units, which are characterized by a hollow globular structure with a diameter between 2.0 and 9.0 mm and a wall thickness of approximately 200 µm. A polyhedron-like net structure, formed mainly by the bacteria, was observed in the wall of the grain units, which has not been reported previously to our knowledge. Towards the inside of the grain unit, the polyhedron-like net structures became gradually larger in diameter and fewer in number. Such fine structures may play a crucial role in the stability of the grains. Subsequently, the distribution, diversity, and shift of yeasts in TKGs were investigated based on thin section, scanning electron microscopy, cloning and sequencing of D1/D2 of the 26S rRNA gene, real-time quantitative PCR, and in situ hybridization with specific fluorescence-labeled oligonucleotide probes. These show that (i) yeasts appear to localize on the outer surface of the grains and grow normally together to form colonies embedded in the bacterial community; (ii) the diversity of yeasts is relatively low on genus level with three dominant species – Saccharomyces cerevisiae, Kluyveromyces marxianus, and Yarrowia lipolytica; (iii) S. cerevisiae is the stable predominant yeast species, while the composition of Kluyveromyces and Yarrowia are subject to change over time. Our results indicate that TKGs are relatively stable in structure, and culture conditions to some extent shape the microbial community and interaction in kefir grains. These findings pave the way for further study of the specific symbiotic associations between S

Forest structure, diversity and soil properties in a dry tropical forest in Rajasthan, Western India

Directory of Open Access Journals (Sweden)

J. I. Nirmal Kumar

2011-06-01

Full Text Available Structure, species composition, and soil properties of a dry tropical forest in Rajasthan Western India, were examined by establishment of 25 plots. The forest was characterized by a relatively low canopy and a large number of small-diameter trees. Mean canopy height for this forest was 10 m and stands contained an average of 995 stems ha-1 (= 3.0 cm DBH; 52% of those stems were smaller than 10 cm DBH. The total basal area was 46.35 m2ha-1, of which Tectona grandis L. contributed 48%. The forest showed high species diversity of trees. 50 tree species (= 3.0 cm DBH from 29 families were identified in the 25 sampling plots. T. grandis (20.81% and Butea monosperma (9% were the dominant and subdominant species in terms of importance value. The mean tree species diversity indices for the plots were 1.08 for Shannon diversity index (H´, 0.71 for equitability index (J´ and 5.57 for species richness index (S´, all of which strongly declined with the increase of importance value of the dominant, T. grandis. Measures of soil nutrients indicated low fertility, extreme heterogeneity. Regression analysis showed that stem density and the dominant tree height were significantly correlated with soil pH. There was a significant positive relationship between species diversity index and soil available P, exchangeable K+, Ca2+ (all p values < 0.001 and a negative relationship with N, C, C:N and C:P ratio. The results suggest that soil properties are major factors influencing forest composition and structure within the dry tropical forest in Rajasthan.

Progressive skin necrosis of a huge occipital encephalocele

Science.gov (United States)

Andarabi, Yasir; Nejat, Farideh; El-Khashab, Mostafa

2008-01-01

Objects: Progressive skin necrosis of giant occipital encephalocoele is an extremely rare complication found in neonates. Infection and ulceration of the necrosed skin may lead to meningitis or sepsis. We present here a neonate with giant occipital encephalocoele showing progressive necrosis during the first day of his life. Methods: A newborn baby was found to have a huge mass in the occipital region, which was covered by normal pink-purplish skin. During the last hours of the first day of his life, the sac started becoming ulcerated accompanied with a rapid color change in the skin, gradually turning darker and then black. The neonate was taken up for urgent excision and repair of the encephalocele. Two years after the operation, he appears to be well-developed without any neurological problems. Conclusion: Necrosis may have resulted from arterial or venous compromise caused by torsion of the pedicle during delivery or after birth. The high pressure inside the sac associated with the thin skin of the encephalocoele may be another predisposing factor. In view of the risk of ulceration and subsequent infection, urgent surgery of the necrotizing encephalocele is suggested. PMID:19753210

Progressive skin necrosis of a huge occipital encephalocele

Directory of Open Access Journals (Sweden)

Andarabi Yasir

2008-01-01

Full Text Available Objects: Progressive skin necrosis of giant occipital encephalocoele is an extremely rare complication found in neonates. Infection and ulceration of the necrosed skin may lead to meningitis or sepsis. We present here a neonate with giant occipital encephalocoele showing progressive necrosis during the first day of his life. Methods: A newborn baby was found to have a huge mass in the occipital region, which was covered by normal pink-purplish skin. During the last hours of the first day of his life, the sac started becoming ulcerated accompanied with a rapid color change in the skin, gradually turning darker and then black. The neonate was taken up for urgent excision and repair of the encephalocele. Two years after the operation, he appears to be well-developed without any neurological problems. Conclusion: Necrosis may have resulted from arterial or venous compromise caused by torsion of the pedicle during delivery or after birth. The high pressure inside the sac associated with the thin skin of the encephalocoele may be another predisposing factor. In view of the risk of ulceration and subsequent infection, urgent surgery of the necrotizing encephalocele is suggested.

Assessment of Genetic Diversity, Relationships and Structure among Korean Native Cattle Breeds Using Microsatellite Markers

Directory of Open Access Journals (Sweden)

Sangwon Suh

2014-11-01

Full Text Available Four Korean native cattle (KNC breeds—Hanwoo, Chikso, Heugu, and Jeju black—are entered in the Domestic Animal Diversity Information System of the United Nations Food and Agriculture Organization (FAO. The objective of this study was to assess the genetic diversity, phylogenetic relationships and population structure of these KNC breeds (n = 120 and exotic breeds (Holstein and Charolais, n = 56. Thirty microsatellite loci recommended by the International Society for Animal Genetics/FAO were genotyped. These genotypes were used to determine the allele frequencies, allelic richness, heterozygosity and polymorphism information content per locus and breed. Genetic diversity was lower in Heugu and Jeju black breeds. Phylogenetic analysis, Factorial Correspondence Analysis and genetic clustering grouped each breed in its own cluster, which supported the genetic uniqueness of the KNC breeds. These results will be useful for conservation and management of KNC breeds as animal genetic resources.

Functional understanding of the diverse exon-intron structures of human GPCR genes.

Science.gov (United States)

Hammond, Dorothy A; Olman, Victor; Xu, Ying

2014-02-01

The GPCR genes have a variety of exon-intron structures even though their proteins are all structurally homologous. We have examined all human GPCR genes with at least two functional protein isoforms, totaling 199, aiming to gain an understanding of what may have contributed to the large diversity of the exon-intron structures of the GPCR genes. The 199 genes have a total of 808 known protein splicing isoforms with experimentally verified functions. Our analysis reveals that 1301 (80.6%) adjacent exon-exon pairs out of the total of 1,613 in the 199 genes have either exactly one exon skipped or the intron in-between retained in at least one of the 808 protein splicing isoforms. This observation has a statistical significance p-value of 2.051762 * e(-09), assuming that the observed splicing isoforms are independent of the exon-intron structures. Our interpretation of this observation is that the exon boundaries of the GPCR genes are not randomly determined; instead they may be selected to facilitate specific alternative splicing for functional purposes.

Soil Effects on Forest Structure and Diversity in a Moist and a Dry Tropical Forest

NARCIS (Netherlands)

Peña-Claros, M.; Poorter, L.; Alarcon, A.; Blate, G.; Choque, U.; Fredericksen, T.S.; Justiniano, J.; Leaño, C.; Licona, J.C.; Pariona, W.; Putz, F.E.; Quevedo, L.; Toledo, M.

2012-01-01

Soil characteristics are important drivers of variation in wet tropical forest structure and diversity, but few studies have evaluated these relationships in drier forest types. Using tree and soil data from 48 and 32 1 ha plots, respectively, in a Bolivian moist and dry forest, we asked how soil

Population size, center-periphery, and seed dispersers' effects on the genetic diversity and population structure of the Mediterranean relict shrub Cneorum tricoccon.

Science.gov (United States)

Lázaro-Nogal, Ana; Matesanz, Silvia; García-Fernández, Alfredo; Traveset, Anna; Valladares, Fernando

2017-09-01

The effect of population size on population genetic diversity and structure has rarely been studied jointly with other factors such as the position of a population within the species' distribution range or the presence of mutualistic partners influencing dispersal. Understanding these determining factors for genetic variation is critical for conservation of relict plants that are generally suffering from genetic deterioration. Working with 16 populations of the vulnerable relict shrub Cneorum tricoccon throughout the majority of its western Mediterranean distribution range, and using nine polymorphic microsatellite markers, we examined the effects of periphery (peripheral vs. central), population size (large vs. small), and seed disperser (introduced carnivores vs. endemic lizards) on the genetic diversity and population structure of the species. Contrasting genetic variation ( H E : 0.04-0.476) was found across populations. Peripheral populations showed lower genetic diversity, but this was dependent on population size. Large peripheral populations showed high levels of genetic diversity, whereas small central populations were less diverse. Significant isolation by distance was detected, indicating that the effect of long-distance gene flow is limited relative to that of genetic drift, probably due to high selfing rates ( F IS  = 0.155-0.887), restricted pollen flow, and ineffective seed dispersal. Bayesian clustering also supported the strong population differentiation and highly fragmented structure. Contrary to expectations, the type of disperser showed no significant effect on either population genetic diversity or structure. Our results challenge the idea of an effect of periphery per se that can be mainly explained by population size, drawing attention to the need of integrative approaches considering different determinants of genetic variation. Furthermore, the very low genetic diversity observed in several small populations and the strong among

Hydrogen-terminated mesoporous silicon monoliths with huge surface area as alternative Si-based visible light-active photocatalysts

KAUST Repository

Li, Ting; Li, Jun; Zhang, Qiang; Blazeby, Emma; Shang, Congxiao; Xu, Hualong; Zhang, Xixiang; Chao, Yimin

2016-01-01

Silicon-based nanostructures and their related composites have drawn tremendous research interest in solar energy storage and conversion. Mesoporous silicon with a huge surface area of 400-900 m2 g-1 developed by electrochemical etching exhibits

Characterization of Linkage Disequilibrium and Population Structure in a Mungbean Diversity Panel

Directory of Open Access Journals (Sweden)

Thomas J. Noble

2018-01-01

Full Text Available Mungbean [Vigna radiata (L. R. Wilczek var. radiata] is an important grain legume globally, providing a high-quality plant protein source largely produced and consumed in South and East Asia. This study aimed to characterize a mungbean diversity panel consisting of 466 cultivated accessions and demonstrate its utility by conducting a pilot genome-wide association study of seed coat color. In addition 16 wild accessions were genotyped for comparison and in total over 22,000 polymorphic genome-wide SNPs were identified and used to analyze the genetic diversity, population structure, linkage disequilibrium (LD of mungbean. Polymorphism was lower in the cultivated accessions in comparison to the wild accessions, with average polymorphism information content values 0.174, versus 0.305 in wild mungbean. LD decayed in ∼100 kb in cultivated lines, a distance higher than the linkage decay of ∼60 kb estimated in wild mungbean. Four distinct subgroups were identified within the cultivated lines, which broadly corresponded to geographic origin and seed characteristics. In a pilot genome-wide association mapping study of seed coat color, five genomic regions associated were identified, two of which were close to seed coat color genes in other species. This mungbean diversity panel constitutes a valuable resource for genetic dissection of important agronomical traits to accelerate mungbean breeding.

Ecological-network models link diversity, structure and function in the plankton food-web

Science.gov (United States)

D'Alelio, Domenico; Libralato, Simone; Wyatt, Timothy; Ribera D'Alcalà, Maurizio

2016-02-01

A planktonic food-web model including sixty-three functional nodes (representing auto- mixo- and heterotrophs) was developed to integrate most trophic diversity present in the plankton. The model was implemented in two variants - which we named ‘green’ and ‘blue’ - characterized by opposite amounts of phytoplankton biomass and representing, respectively, bloom and non-bloom states of the system. Taxonomically disaggregated food-webs described herein allowed to shed light on how components of the plankton community changed their trophic behavior in the two different conditions, and modified the overall functioning of the plankton food web. The green and blue food-webs showed distinct organizations in terms of trophic roles of the nodes and carbon fluxes between them. Such re-organization stemmed from switches in selective grazing by both metazoan and protozoan consumers. Switches in food-web structure resulted in relatively small differences in the efficiency of material transfer towards higher trophic levels. For instance, from green to blue states, a seven-fold decrease in phytoplankton biomass translated into only a two-fold decrease in potential planktivorous fish biomass. By linking diversity, structure and function in the plankton food-web, we discuss the role of internal mechanisms, relying on species-specific functionalities, in driving the ‘adaptive’ responses of plankton communities to perturbations.

Genetic diversity and structure of Brazilian ginger germplasm (Zingiber officinale) revealed by AFLP markers.

Science.gov (United States)

Blanco, Eleonora Zambrano; Bajay, Miklos Maximiliano; Siqueira, Marcos Vinícius Bohrer Monteiro; Zucchi, Maria Imaculada; Pinheiro, José Baldin

2016-12-01

Ginger is a vegetable with medicinal and culinary properties widely cultivated in the Southern and Southeastern Brazil. The knowledge of ginger species' genetic variability is essential to direct correctly future studies of conservation and genetic improvement, but in Brazil, little is known about this species' genetic variability. In this study, we analyzed the genetic diversity and structure of 55 Brazilian accessions and 6 Colombian accessions of ginger, using AFLP (Amplified Fragment Length Polymorphism) molecular markers. The molecular characterization was based on 13 primers combinations, which generated an average of 113.5 polymorphic loci. The genetic diversity estimates of Nei (Hj), Shannon-Weiner index (I) and an effective number of alleles (n e ) were greater in the Colombian accessions in relation to the Brazilian accessions. The analysis of molecular variance showed that most of the genetic variation occurred between the two countries while in the Brazilian populations there is no genetic structure and probably each region harbors 100 % of genetic variation found in the samples. The bayesian model-based clustering and the dendrogram using the dissimilarity's coefficient of Jaccard were congruent with each other and showed that the Brazilian accessions are highly similar between themselves, regardless of the geographic region of origin. We suggested that the exploration of the interspecific variability and the introduction of new varieties of Z.officinale are viable alternatives for generating diversity in breeding programs in Brazil. The introduction of new genetic materials will certainly contribute to a higher genetic basis of such crop.

Genetic diversity and structure of Megabalanus azoricus in the Azores: Implications for aquaculture management

Science.gov (United States)

De Girolamo, Mirko; Torboli, Valentina; Pallavicini, Alberto; Isidro, Eduardo

2017-11-01

Megabalanus azoricus giant barnacles are the most traditional seafood of the Azores archipelago (NE Atlantic). This valuable commercial species has been highly exploited in the past and it is considered one of the key species for the development of aquaculture in the region. Despite the importance for conservation and aquaculture there is still a lack of basic information about M. azoricus genetic diversity and population structure. Here we used seven microsatellites markers to analyse 300 samples collected at six out of nine islands of the Azores archipelago, including also different locations from a single island, to provide information on the scale of genetic diversity and population structure of this species. Parameters like heterozygosity, allelic richness and effective number of alleles indicated a high genetic diversity and variability among islands. Pairwise comparisons and PCoA analysis on FST and Jost's DEST showed significant and evident differentiation among sampling locations. Additionally, AMOVA allocates a small (6.02%) but statistically significant portion of the variance to the among Island level revealing also a weak resolution (1.87%) at finer scale. Additionally Monte Carlo resampling methods indicated the most likely sources of the recruits were the local or adjacent populations. Genetic risks associated with the giant barnacle potential production scheme should be taken into account in a future management plan delimiting, as precautionary measure, this culture at a single island or at groups of islands here identified. Moreover a monitoring strategy should be implemented with the aim to evaluate possible changes in genetic parameters of native populations.

Genetic diversity and a population structure analysis of accessions in the Chinese cowpea [Vigna unguiculata (L. Walp.] germplasm collection

Directory of Open Access Journals (Sweden)

Honglin Chen

2017-10-01

Full Text Available Cowpea (Vigna unguiculata is an important legume crop with diverse uses. The species is presently a minor crop, and evaluation of its genetic diversity has been very limited. In this study, a total of 200 genic and 100 genomic simple sequence repeat (SSR markers were developed from cowpea unigene and genome sequences, respectively. Among them, 27 genic and 27 genomic SSR markers were polymorphic and were used for assessment of genetic diversity and population structure in 105 selected cowpea accessions. A total of 155 alleles and 2.9 alleles per marker were identified, and the average polymorphic information content (PIC value was 0.3615. The average PIC of genomic SSRs (0.3996 was higher than that of genic SSRs (0.3235, and most of the polymorphic genomic SSRs were composed of di- and trinucleotide repeats (51.9% and 37.0% of all loci, respectively. The low level of detected genetic diversity may be attributed to a severe genetic bottleneck that occurred during the cowpea domestication process. The accessions were classified by structure and cluster analysis into four subgroups that correlated well with their geographic origins or collection sites. The classification results were also consistent with the results from principal coordinate analysis and can be used as a guide during future germplasm collection and selection of accessions as breeding materials for cultivar improvement. The newly developed genic and genomic SSR markers described in this study will be valuable genomic resources for the assessment of genetic diversity, population structure, evaluation of germplasm accessions, construction of genetic maps, identification of genes of interest, and application of marker-assisted selection in cowpea breeding programs.

Genetic diversity and population structure of Lactobacillus delbrueckii subspecies bulgaricus isolated from naturally fermented dairy foods.

Science.gov (United States)

Song, Yuqin; Sun, Zhihong; Guo, Chenyi; Wu, Yarong; Liu, Wenjun; Yu, Jie; Menghe, Bilige; Yang, Ruifu; Zhang, Heping

2016-03-04

Lactobacillus delbrueckii subsp. bulgaricus is one of the most widely used starter culture strains in industrial fermented dairy manufacture. It is also common in naturally fermented dairy foods made using traditional methods. The subsp. bulgaricus strains found in naturally fermented foods may be useful for improving current industrial starter cultures; however, little is known regarding its genetic diversity and population structure. Here, a collection of 298 L. delbrueckii strains from naturally fermented products in Mongolia, Russia, and West China was analyzed by multi-locus sequence typing based on eight conserved genes. The 251 confirmed subsp. bulgaricus strains produced 106 unique sequence types, the majority of which were assigned to five clonal complexes (CCs). The geographical distribution of CCs was uneven, with CC1 dominated by Mongolian and Russian isolates, and CC2-CC5 isolates exclusively from Xinjiang, China. Population structure analysis suggested six lineages, L1-L6, with various homologous recombination rates. Although L2-L5 were mainly restricted within specific regions, strains belonging to L1 and L6 were observed in diverse regions, suggesting historical transmission events. These results greatly enhance our knowledge of the population diversity of subsp. bulgaricus strains, and suggest that strains from CC1 and L4 may be useful as starter strains in industrial fermentation.

A population on the edge: genetic diversity and population structure of the world's northernmost harbour seals (Phoca vitulina)

DEFF Research Database (Denmark)

Andersen, Liselotte Wesley; Lydersen, Christian; Frie, Anne Kirstine

2011-01-01

insight into consequences of population declines in a broader conservation context. The harbour seal population at Svalbard is the world's northernmost harbour seal population. Nothing is known about the genetic diversity, distinctiveness or origin of this small, marginalized mammalian population. Thus......  It is crucial to examine the genetic diversity and structure of small, isolated populations, especially those at the edge of their distribution range, because they are vulnerable to stochastic processes if genetic diversity is low and isolation level high, and because such populations provide...... microsatellites and variation in the D-loop. Each of the four locations was a genetically distinct population. The Svalbard population was highly genetically distinct, had reduced genetic diversity, received limited gene flow, had a rather low effective population size and showed an indication of having...

Modeling the binding affinity of structurally diverse industrial chemicals to carbon using the artificial intelligence approaches.

Science.gov (United States)

Gupta, Shikha; Basant, Nikita; Rai, Premanjali; Singh, Kunwar P

2015-11-01

Binding affinity of chemical to carbon is an important characteristic as it finds vast industrial applications. Experimental determination of the adsorption capacity of diverse chemicals onto carbon is both time and resource intensive, and development of computational approaches has widely been advocated. In this study, artificial intelligence (AI)-based ten different qualitative and quantitative structure-property relationship (QSPR) models (MLPN, RBFN, PNN/GRNN, CCN, SVM, GEP, GMDH, SDT, DTF, DTB) were established for the prediction of the adsorption capacity of structurally diverse chemicals to activated carbon following the OECD guidelines. Structural diversity of the chemicals and nonlinear dependence in the data were evaluated using the Tanimoto similarity index and Brock-Dechert-Scheinkman statistics. The generalization and prediction abilities of the constructed models were established through rigorous internal and external validation procedures performed employing a wide series of statistical checks. In complete dataset, the qualitative models rendered classification accuracies between 97.04 and 99.93%, while the quantitative models yielded correlation (R(2)) values of 0.877-0.977 between the measured and the predicted endpoint values. The quantitative prediction accuracies for the higher molecular weight (MW) compounds (class 4) were relatively better than those for the low MW compounds. Both in the qualitative and quantitative models, the Polarizability was the most influential descriptor. Structural alerts responsible for the extreme adsorption behavior of the compounds were identified. Higher number of carbon and presence of higher halogens in a molecule rendered higher binding affinity. Proposed QSPR models performed well and outperformed the previous reports. A relatively better performance of the ensemble learning models (DTF, DTB) may be attributed to the strengths of the bagging and boosting algorithms which enhance the predictive accuracies. The

Low Genetic Diversity and Structuring of the Arapaima (Osteoglossiformes, Arapaimidae Population of the Araguaia-Tocantins Basin

Directory of Open Access Journals (Sweden)

Carla A. Vitorino

2017-10-01

Full Text Available The arapaima, Arapaima gigas, is a fish whose populations are threatened by both overfishing and the ongoing destruction of its natural habitats. In the Amazon basin, varying levels of population structure have been found in A. gigas, although no data are available on the genetic diversity or structure of the populations found in the Araguaia-Tocantins basin, which has a topographic profile, hydrological regime, and history of fishing quite distinct from those of the Amazon. In this context, microsatellite markers were used to assess the genetic diversity and connectivity of five wild A. gigas populations in the Araguaia-Tocantins basin. The results of the analysis indicated low levels of genetic diversity in comparison with other A. gigas populations, studied in the Amazon basin. The AMOVA revealed that the Arapaima populations of the Araguaia-Tocantins basin are structured significantly. No correlation was found between pairwise FST values and the geographical distance among populations. The low level of genetic variability and the evidence of restricted gene flow may both be accounted for by overfishing, as well as the other human impacts that these populations have been exposed to over the years. The genetic fragility of these populations demands attention, given that future environmental changes (natural or otherwise may further reduce these indices and eventually endanger these populations. The results of this study emphasize the need to take the genetic differences among the study populations into account when planning management measures and conservation strategies for the arapaima stocks of the Araguaia-Tocantins basin.

Low Genetic Diversity and Structuring of the Arapaima (Osteoglossiformes, Arapaimidae) Population of the Araguaia-Tocantins Basin.

Science.gov (United States)

Vitorino, Carla A; Nogueira, Fabrícia; Souza, Issakar L; Araripe, Juliana; Venere, Paulo C

2017-01-01

The arapaima, Arapaima gigas , is a fish whose populations are threatened by both overfishing and the ongoing destruction of its natural habitats. In the Amazon basin, varying levels of population structure have been found in A. gigas , although no data are available on the genetic diversity or structure of the populations found in the Araguaia-Tocantins basin, which has a topographic profile, hydrological regime, and history of fishing quite distinct from those of the Amazon. In this context, microsatellite markers were used to assess the genetic diversity and connectivity of five wild A. gigas populations in the Araguaia-Tocantins basin. The results of the analysis indicated low levels of genetic diversity in comparison with other A. gigas populations, studied in the Amazon basin. The AMOVA revealed that the Arapaima populations of the Araguaia-Tocantins basin are structured significantly. No correlation was found between pairwise F ST values and the geographical distance among populations. The low level of genetic variability and the evidence of restricted gene flow may both be accounted for by overfishing, as well as the other human impacts that these populations have been exposed to over the years. The genetic fragility of these populations demands attention, given that future environmental changes (natural or otherwise) may further reduce these indices and eventually endanger these populations. The results of this study emphasize the need to take the genetic differences among the study populations into account when planning management measures and conservation strategies for the arapaima stocks of the Araguaia-Tocantins basin.

Genetic diversity and population structure analysis in Perilla frutescens from Northern areas of China based on simple sequence repeats.

Science.gov (United States)

Ma, S J; Sa, K J; Hong, T K; Lee, J K

2017-09-21

In this study, 21 simple sequence repeat (SSR) markers were used to evaluate the genetic diversity and population structure among 77 Perilla accessions from high-latitude and middle-latitude areas of China. Ninety-five alleles were identified with an average of 4.52 alleles per locus. The average polymorphic information content (PIC) and genetic diversity values were 0.346 and 0.372, respectively. The level of genetic diversity and PIC value for cultivated accessions of Perilla frutescens var. frutescens from middle-latitude areas were higher than accessions from high-latitude areas. Based on the dendrogram of unweighted pair group method with arithmetic mean (UPGMA), all accessions were classified into four major groups with a genetic similarity of 46%. All accessions of the cultivated var. frutescens were discriminated from the cultivated P. frutescens var. crispa. Furthermore, most accessions of the cultivated var. frutescens collected in high-latitude and middle-latitude areas were distinguished depending on their geographical location. However, the geographical locations of several accessions of the cultivated var. frutescens have no relation with their positions in the UPGMA dendrogram and population structure. This result implies that the diffusion of accessions of the cultivated Perilla crop in the northern areas of China might be through multiple routes. On the population structure analysis, 77 Perilla accessions were divided into Group I, Group II, and an admixed group based on a membership probability threshold of 0.8. Finally, the findings in this study can provide useful theoretical knowledge for further study on the population structure and genetic diversity of Perilla and benefit for Perilla crop breeding and germplasm conservation.

Genetic structure and diversity of indigenous rice (Oryza sativa) varieties in the Eastern Himalayan region of Northeast India.

Science.gov (United States)

Choudhury, Baharul; Khan, Mohamed Latif; Dayanandan, Selvadurai

2013-12-01

The Eastern Himalayan region of Northeast (NE) India is home to a large number of indigenous rice varieties, which may serve as a valuable genetic resource for future crop improvement to meet the ever-increasing demand for food production. However, these varieties are rapidly being lost due to changes in land-use and agricultural practices, which favor agronomically improved varieties. A detailed understanding of the genetic structure and diversity of indigenous rice varieties is crucial for efficient utilization of rice genetic resources and for developing suitable conservation strategies. To explore the genetic structure and diversity of rice varieties in NE India, we genotyped 300 individuals of 24 indigenous rice varieties representing sali, boro, jum and glutinous types, 5 agronomically improved varieties, and one wild rice species (O. rufipogon) using seven SSR markers. A total of 85 alleles and a very high level of gene diversity (0.776) were detected among the indigenous rice varieties of the region. Considerable level of genetic variation was found within indigenous varieties whereas improved varieties were monoporphic across all loci. The comparison of genetic diversity among different types of rice revealed that sali type possessed the highest gene diversity (0.747) followed by jum (0.627), glutinous (0.602) and boro (0.596) types of indigenous rice varieties, while the lowest diversity was detected in agronomically improved varieties (0.459). The AMOVA results showed that 66% of the variation was distributed among varieties indicating a very high level of genetic differentiation in rice varieties in the region. Two major genetically defined clusters corresponding to indica and japonica groups were detected in rice varieties of the region. Overall, traditionally cultivated indigenous rice varieties in NE India showed high levels of genetic diversity comparable to levels of genetic diversity reported from wild rice populations in various parts of the

Species and structural diversity affect growth of oak, but not pine, in uneven-aged mature forests

NARCIS (Netherlands)

Vanhellemont, Margot; Bijlsma, Rienk Jan; Keersmaeker, De Luc; Vandekerkhove, Kris; Verheyen, Kris

2018-01-01

The effects of mixing tree species on tree growth and stand production have been abundantly studied, mostly looking at tree species diversity effects while controlling for stand density and structure. Regarding the shift towards managing forests as complex adaptive systems, we also need insight into

Solid‐Phase Synthesis of Structurally Diverse Heterocycles by an Amide–Ketone Condensation/N‐Acyliminium Pictet–Spengler Sequence

DEFF Research Database (Denmark)

Komnatnyy, Vitaly V.; Givskov, Michael Christian; Nielsen, Thomas Eiland

2012-01-01

An efficient approach for the solid‐phase synthesis of structurally diverse heterocyclic compounds is presented. Under acidic reaction conditions, peptidic levulinamides undergo intramolecular ketone–amide condensation reactions to form cyclic N‐acyliminium intermediates. In the presence...

Spatial Structure of Soil Macrofauna Diversity and Tree Canopy in Riparian Forest of Maroon River

Directory of Open Access Journals (Sweden)

Ehsan Sayad

2017-02-01

with a mean temperature of 24.5oc. Plant cover, mainly comprises Populus euphratica Olivie and Tamarix arceuthoides Bge and Lycium shawii Roemer & Schultes. Soil macrofauna were sampled using 175 sampling point along parallel transects (perpendicular to the river. The distance between transects was 100m. We considered distance between samples as 50 m. tree canopy were measured in 5* 5 plots. soil macrofauna were extracted from 50 cm×50 cm×10 cm soil monolith by hand-sorting procedure. All soil macrofauna were identified to family level. Evenness (Sheldon index, richness (Menhinich index and diversity (Shannon H’ index by using PAST version 1.39, were determined in each sample. Classical statistical parameters, i.e. mean, standard deviation, coefficient of variation, minimum and maximum, were calculated using SPSS17 software. For analysis of the relationship between Soil macrofauna diversity indices and tree canopy (Total canopy, Populous canopy, Tamarix canopy and Serim canopy we calculated the correlation among soil properties and macrofauna using the Pearson correlation coefficient. Next, to determining the spatial structure, we calculated the semivariances. Semivariance quantifies the spatial dependence of spatially ordered variable values. In order to gather information about the spatial connection between any two variables, and to compare the similarity of their spatial structure patterns, cross-variograms were constructed. Cross-variograms are plots of cross-semivariance against the lag distance. Results and Discussion: Soil macrofauna communities were dominated by earthworm, diplopods, coleoptera, gastropoda, araneae, and insect larvae. Correlation analysis of soil macrofauna and tree canopy indicated weak relationships between them. Weak, but significant relationships were found between macrofauna diversity, evenness, richness and total canopy, Populous canopy and Tamarix canopy (positive. Macrofauna indices and tree canopy(excepted Tamarix canopy were

The levels of fruit organization in Celastraceae and structural diversity of pirenariums in Cassinoideae

OpenAIRE

Ivan A. Savinov

2012-01-01

The levels of fruit organization are determined for the Celastraceae family on the basis of fruit morphology and anatomical study of pericarp (114 species from 45 genera. Analysis of their correlation with basal and derivative lineages according to the last molecular data is conducted and reconstruction of initial stages of the family phylogeny is presented. Special focus to structural diversity of pirenarium in Cassinoideae subfamily is spared.

Diverse Asian American Families and Communities: Culture, Structure, and Education (Part 1: Why They Differ)

Science.gov (United States)

Paik, Susan J.; Rahman, Zaynah; Kula, Stacy M.; Saito, L. Erika; Witenstein, Matthew A.

2017-01-01

Based on 11 diverse Asian American (AA) communities, this article discusses the similarities and differences across East, South, and Southeast Asians. Of two parts in this journal issue, Part 1 presents a review of literature and census data to understand the cultural and structural factors of different types of coethnic communities (strong, weak,…

Synergy of VSWIR and LiDAR for Ecosystem Structure, Biomass, and Canopy Diversity

Science.gov (United States)

Cook, Bruce D.; Asner, Gregory P.

2010-01-01

This slide presentation reviews the use of Visible ShortWave InfraRed (VSWIR) Imaging Spectrometer and LiDAR to study ecosystem structure, biomass and canopy diversity. It is shown that the biophysical data from LiDAR and biochemical information from hyperspectral remote sensing provides complementary data for: (1) describing spatial patterns of vegetation and biodiversity, (2) characterizing relationships between ecosystem form and function, and (3) detecting natural and human induced change that affects the biogeochemical cycles.

Characterizing the population structure and genetic diversity of maize breeding germplasm in Southwest China using genome-wide SNP markers.

Science.gov (United States)

Zhang, Xiao; Zhang, Hua; Li, Lujiang; Lan, Hai; Ren, Zhiyong; Liu, Dan; Wu, Ling; Liu, Hailan; Jaqueth, Jennifer; Li, Bailin; Pan, Guangtang; Gao, Shibin

2016-08-31

Maize breeding germplasm used in Southwest China has high complexity because of the diverse ecological features of this area. In this study, the population structure, genetic diversity, and linkage disequilibrium decay distance of 362 important inbred lines collected from the breeding program of Southwest China were characterized using the MaizeSNP50 BeadChip with 56,110 single nucleotide polymorphisms (SNPs). With respect to population structure, two (Tropical and Temperate), three (Tropical, Stiff Stalk and non-Stiff Stalk), four [Tropical, group A germplasm derived from modern U.S. hybrids (PA), group B germplasm derived from modern U.S. hybrids (PB) and Reid] and six (Tropical, PB, Reid, Iowa Stiff Stalk Synthetic, PA and North) subgroups were identified. With increasing K value, the Temperate group showed pronounced hierarchical structure with division into further subgroups. The Genetic Diversity of each group was also estimated, and the Tropical group was more diverse than the Temperate group. Seven low-genetic-diversity and one high-genetic-diversity regions were collectively identified in the Temperate, Tropical groups, and the entire panel. SNPs with significant variation in allele frequency between the Tropical and Temperate groups were also evaluated. Among them, a region located at 130 Mb on Chromosome 2 showed the highest genetic diversity, including both number of SNPs with significant variation and the ratio of significant SNPs to total SNPs. Linkage disequilibrium decay distance in the Temperate group was greater (2.5-3 Mb) than that in the entire panel (0.5-0.75 Mb) and the Tropical group (0.25-0.5 Mb). A large region at 30-120 Mb of Chromosome 7 was concluded to be a region conserved during the breeding process by comparison between S37, which was considered a representative tropical line in Southwest China, and its 30 most similar derived lines. For the panel covered most of widely used inbred lines in Southwest China, this work

Population structure and genetic diversity of the giant anteater (Myrmecophaga tridactyla: Myrmecophagidae, Pilosa in Brazil

Directory of Open Access Journals (Sweden)

Camila L. Clozato

Full Text Available Abstract The giant anteater (Myrmecophaga tridactyla, Pilosa, Linnaeus 1758 belongs to the mammalian order Pilosa and presents a large distribution along South America, occupying a great variety of habitats. It is listed in the IUCN Red List of threatened species as Vulnerable. Despite threatened, there is a lack of studies regarding its genetic variability. The aim of this study was to examine the genetic diversity and patterns of genetic structure within remaining populations. We analyzed 77 individuals from seven different populations distributed in four biomes across Brazil: Cerrado, Pantanal, Atlantic Forest and Amazon Forest. We sequenced two mitochondrial markers (control region and Cyt-b and two nuclear markers (AMELY and RAG2. We found high genetic diversity within subpopulations from National Parks of Serra da Canastra and Emas, both within the Cerrado biome, with signs of population expansion. Besides, we found a notable population structure between populations from the Cerrado/Pantanal and Amazon Forest biomes. This data is a major contribution to the knowledge of the evolutionary history of the species and to future management actions concerning its conservation.

Population structure and genetic diversity of the giant anteater (Myrmecophaga tridactyla: Myrmecophagidae, Pilosa) in Brazil.

Science.gov (United States)

Clozato, Camila L; Miranda, Flávia R; Lara-Ruiz, Paula; Collevatti, Rosane G; Santos, Fabrício R

2017-01-01

The giant anteater (Myrmecophaga tridactyla, Pilosa, Linnaeus 1758) belongs to the mammalian order Pilosa and presents a large distribution along South America, occupying a great variety of habitats. It is listed in the IUCN Red List of threatened species as Vulnerable. Despite threatened, there is a lack of studies regarding its genetic variability. The aim of this study was to examine the genetic diversity and patterns of genetic structure within remaining populations. We analyzed 77 individuals from seven different populations distributed in four biomes across Brazil: Cerrado, Pantanal, Atlantic Forest and Amazon Forest. We sequenced two mitochondrial markers (control region and Cyt-b) and two nuclear markers (AMELY and RAG2). We found high genetic diversity within subpopulations from National Parks of Serra da Canastra and Emas, both within the Cerrado biome, with signs of population expansion. Besides, we found a notable population structure between populations from the Cerrado/Pantanal and Amazon Forest biomes. This data is a major contribution to the knowledge of the evolutionary history of the species and to future management actions concerning its conservation.

The Sg-1 Glycosyltransferase Locus Regulates Structural Diversity of Triterpenoid Saponins of Soybean[W][OA

Science.gov (United States)

Sayama, Takashi; Ono, Eiichiro; Takagi, Kyoko; Takada, Yoshitake; Horikawa, Manabu; Nakamoto, Yumi; Hirose, Aya; Sasama, Hiroko; Ohashi, Mihoko; Hasegawa, Hisakazu; Terakawa, Teruhiko; Kikuchi, Akio; Kato, Shin; Tatsuzaki, Nana; Tsukamoto, Chigen; Ishimoto, Masao

2012-01-01

Triterpene saponins are a diverse group of biologically functional products in plants. Saponins usually are glycosylated, which gives rise to a wide diversity of structures and functions. In the group A saponins of soybean (Glycine max), differences in the terminal sugar species located on the C-22 sugar chain of an aglycone core, soyasapogenol A, were observed to be under genetic control. Further genetic analyses and mapping revealed that the structural diversity of glycosylation was determined by multiple alleles of a single locus, Sg-1, and led to identification of a UDP-sugar–dependent glycosyltransferase gene (Glyma07g38460). Although their sequences are highly similar and both glycosylate the nonacetylated saponin A0-αg, the Sg-1a allele encodes the xylosyltransferase UGT73F4, whereas Sg-1b encodes the glucosyltransferase UGT73F2. Homology models and site-directed mutagenesis analyses showed that Ser-138 in Sg-1a and Gly-138 in Sg-1b proteins are crucial residues for their respective sugar donor specificities. Transgenic complementation tests followed by recombinant enzyme assays in vitro demonstrated that sg-10 is a loss-of-function allele of Sg-1. Considering that the terminal sugar species in the group A saponins are responsible for the strong bitterness and astringent aftertastes of soybean seeds, our findings herein provide useful tools to improve commercial properties of soybean products. PMID:22611180

The causes and the nursing interventions of the complications due to repeated embolization therapy for huge cerebral arteriovenous malformations

International Nuclear Information System (INIS)

Sun Lingfang; Sun Ge

2010-01-01

Objective: To investigate the causes of the complications occurred after repeated embolization therapy for huge cerebral arteriovenous malformations and to discuss their nursing interventions. Methods: A total of 54 embolization procedures were performed in 17 patients with huge cerebral arteriovenous malformations. The clinical data were retrospectively analyzed. The causes of complications were carefully examined and the preventive measures were discussed. The prompt and necessary nursing interventions were formulated in order to prevent the complications or serious consequences. Results: Among the total 17 patients, one patient gave up the treatment because of the cerebral hemorrhage which occurred two months after receiving 3 times of embolization therapy. One patient experienced cerebral vascular spasm during the procedure, which was relieved after antispasmodic medication and no neurological deficit was left behind. Two patients developed transient dizziness and headache, which were alleviated spontaneously. One patient presented with nervousness, fear and irritability, which made him hard to cooperate with the operation and the basis intravenous anesthesia was employed. No complications occurred in the remaining cases. Conclusion: The predictive nursing interventions for the prevention of complications are very important for obtaining a successful repeated embolization therapy for huge cerebral arteriovenous malformations, which will ensure that the patients can get the best treatment and the complications can be avoided. (authors)

Diverse binding site structures revealed in homology models of polyreactive immunoglobulins

Science.gov (United States)

Ramsland, Paul A.; Guddat, Luke W.; Edmundson, Allen B.; Raison, Robert L.

1997-09-01

We describe here computer-assisted homology models of the combiningsite structure of three polyreactive immunoglobulins. Template-based modelsof Fv (VL-VH) fragments were derived forthe surface IgM expressed by the malignant CD5 positive B cells from threepatients with chronic lymphocytic leukaemia (CLL). The conserved frameworkregions were constructed using crystal coordinates taken from highlyhomologous human variable domain structures (Pot and Hil). Complementaritydetermining regions (CDRs) were predicted by grafting loops, taken fromknown immunoglobulin structures, onto the Fv framework models. The CDRtemplates were chosen, where possible, to be of the same length and of highresidue identity or similarity. LCDR1, 2 and 3 as well as HCDR1 and 2 forthe Fv were constructed using this strategy. For HCDR3 prediction, adatabase containing the Cartesian coordinates of 30 of these loops wascompiled from unliganded antibody X-ray crystallographic structures and anHCDR3 of the same length as that of the B CLL Fv was selected as a template.In one case (Yar), the resulting HCDR3 model gave unfavourable interactionswhen incorporated into the Fv model. This HCDR3 was therefore modelled usingan alternative strategy of construction of the loop stems, using apreviously described HCDR3 conformation (Pot), followed by chain closurewith a β-turn. The template models were subjected to positionalrefinement using energy minimisation and molecular dynamics simulations(X-PLOR). An electrostatic surface description (GRASP) did not reveal acommon structural feature within the binding sites of the three polyreactiveFv. Thus, polyreactive immunoglobulins may recognise similar and multipleantigens through a diverse array of binding site structures.

Genetic Diversity and Population Structure of Broomcorn Millet (Panicum miliaceum L.) Cultivars and Landraces in China Based on Microsatellite Markers

Science.gov (United States)

Liu, Minxuan; Xu, Yue; He, Jihong; Zhang, Shuang; Wang, Yinyue; Lu, Ping

2016-01-01

Broomcorn millet (Panicum miliaceum L.), one of the first domesticated crops, has been grown in Northern China for at least 10,000 years. The species is presently a minor crop, and evaluation of its genetic diversity has been very limited. In this study, we analyzed the genetic diversity of 88 accessions of broomcorn millet collected from various provinces of China. Amplification with 67 simple sequence repeat (SSR) primers revealed moderate levels of diversity in the investigated accessions. A total of 179 alleles were detected, with an average of 2.7 alleles per locus. Polymorphism information content and expected heterozygosity ranged from 0.043 to 0.729 (mean = 0.376) and 0.045 to 0.771 (mean = 0.445), respectively. Cluster analysis based on the unweighted pair group method of mathematical averages separated the 88 accessions into four groups at a genetic similarity level of 0.633. A genetic structure assay indicated a close correlation between geographical regions and genetic diversity. The uncovered information will be valuable for defining gene pools and developing breeding programs for broomcorn millet. Furthermore, the millet-specific SSR markers developed in this study should serve as useful tools for assessment of genetic diversity and elucidation of population structure in broomcorn millet. PMID:26985894

Evolution of structural diversity of trichothecenes, a family of toxins produced by plant pathogenic and entomopathogenic fungi.

Science.gov (United States)

Proctor, Robert H; McCormick, Susan P; Kim, Hye-Seon; Cardoza, Rosa E; Stanley, April M; Lindo, Laura; Kelly, Amy; Brown, Daren W; Lee, Theresa; Vaughan, Martha M; Alexander, Nancy J; Busman, Mark; Gutiérrez, Santiago

2018-04-01

Trichothecenes are a family of terpenoid toxins produced by multiple genera of fungi, including plant and insect pathogens. Some trichothecenes produced by the fungus Fusarium are among the mycotoxins of greatest concern to food and feed safety because of their toxicity and frequent occurrence in cereal crops, and trichothecene production contributes to pathogenesis of some Fusarium species on plants. Collectively, fungi produce over 150 trichothecene analogs: i.e., molecules that share the same core structure but differ in patterns of substituents attached to the core structure. Here, we carried out genomic, phylogenetic, gene-function, and analytical chemistry studies of strains from nine fungal genera to identify genetic variation responsible for trichothecene structural diversity and to gain insight into evolutionary processes that have contributed to the variation. The results indicate that structural diversity has resulted from gain, loss, and functional changes of trichothecene biosynthetic (TRI) genes. The results also indicate that the presence of some substituents has arisen independently in different fungi by gain of different genes with the same function. Variation in TRI gene duplication and number of TRI loci was also observed among the fungi examined, but there was no evidence that such genetic differences have contributed to trichothecene structural variation. We also inferred ancestral states of the TRI cluster and trichothecene biosynthetic pathway, and proposed scenarios for changes in trichothecene structures during divergence of TRI cluster homologs. Together, our findings provide insight into evolutionary processes responsible for structural diversification of toxins produced by pathogenic fungi.

Surface ocean metabarcoding confirms limited diversity in planktonic foraminifera but reveals unknown hyper-abundant lineages.

Science.gov (United States)

Morard, Raphaël; Garet-Delmas, Marie-José; Mahé, Frédéric; Romac, Sarah; Poulain, Julie; Kucera, Michal; de Vargas, Colomban

2018-02-07

Since the advent of DNA metabarcoding surveys, the planktonic realm is considered a treasure trove of diversity, inhabited by a small number of abundant taxa, and a hugely diverse and taxonomically uncharacterized consortium of rare species. Here we assess if the apparent underestimation of plankton diversity applies universally. We target planktonic foraminifera, a group of protists whose known morphological diversity is limited, taxonomically resolved and linked to ribosomal DNA barcodes. We generated a pyrosequencing dataset of ~100,000 partial 18S rRNA foraminiferal sequences from 32 size fractioned photic-zone plankton samples collected at 8 stations in the Indian and Atlantic Oceans during the Tara Oceans expedition (2009-2012). We identified 69 genetic types belonging to 41 morphotaxa in our metabarcoding dataset. The diversity saturated at local and regional scale as well as in the three size fractions and the two depths sampled indicating that the diversity of foraminifera is modest and finite. The large majority of the newly discovered lineages occur in the small size fraction, neglected by classical taxonomy. These unknown lineages dominate the bulk [>0.8 µm] size fraction, implying that a considerable part of the planktonic foraminifera community biomass has its origin in unknown lineages.

Leaf bacterial diversity mediates plant diversity and ecosystem function relationships.

Science.gov (United States)

Laforest-Lapointe, Isabelle; Paquette, Alain; Messier, Christian; Kembel, Steven W

2017-06-01

Research on biodiversity and ecosystem functioning has demonstrated links between plant diversity and ecosystem functions such as productivity. At other trophic levels, the plant microbiome has been shown to influence host plant fitness and function, and host-associated microbes have been proposed to influence ecosystem function through their role in defining the extended phenotype of host organisms However, the importance of the plant microbiome for ecosystem function has not been quantified in the context of the known importance of plant diversity and traits. Here, using a tree biodiversity-ecosystem functioning experiment, we provide strong support for the hypothesis that leaf bacterial diversity is positively linked to ecosystem productivity, even after accounting for the role of plant diversity. Our results also show that host species identity, functional identity and functional diversity are the main determinants of leaf bacterial community structure and diversity. Our study provides evidence of a positive correlation between plant-associated microbial diversity and terrestrial ecosystem productivity, and a new mechanism by which models of biodiversity-ecosystem functioning relationships can be improved.

Medicare Accountable Care Organizations of Diverse Structures Achieve Comparable Quality and Cost Performance.

Science.gov (United States)

Comfort, Leeann N; Shortell, Stephen M; Rodriguez, Hector P; Colla, Carrie H

2018-01-31

To examine whether an empirically derived taxonomy of Accountable Care Organizations (ACOs) is associated with quality and spending performance among patients of ACOs in the Medicare Shared Savings Program (MSSP). Three waves of the National Survey of ACOs and corresponding publicly available Centers for Medicare & Medicaid Services performance data for NSACO respondents participating in the MSSP (N = 204); SK&A Office Based Physicians Database from QuintilesIMS. We compare the performance of three ACO types (physician-led, integrated, and hybrid) for three domains: quality, spending, and likelihood of achieving savings. Sources of performance variation within and between ACO types are compared for each performance measure. There is greater heterogeneity within ACO types than between ACO types. There were no consistent differences in quality by ACO type, nor were there differences in likelihood of achieving savings or overall spending per-person-year. There was evidence for higher spending on physician services for physician-led ACOs. ACOs of diverse structures perform comparably on core MSSP quality and spending measures. CMS should maintain its flexibility and continue to support participation of diverse ACOs. Future research to identify modifiable organizational factors that account for performance variation within ACO types may provide insight as to how best to improve ACO performance based on organizational structure and ownership. © Health Research and Educational Trust.

Genetic diversity and population genetic structure of the only population of Aoluguya Reindeer (Rangifer tarandus) in China.

Science.gov (United States)

Ju, Yan; Liu, Huamiao; Rong, Min; Zhang, Ranran; Dong, Yimeng; Zhou, Yongna; Xing, Xiumei

2018-04-16

Aoluguya Reindeer is the only reindeer species in China and currently approximately 1000 Aoluguya Reindeer remain semi-domesticated. A relative low diversity estimate was found by investigating genetic variability and demographic history of its population. Mismatch distribution curve of its nucleotide sequences and neutral test indicate its population has not experienced expansion. Genetic diversity and population structure were also analysed by using its mtDNA and microsatellites technology. Statistical results of these analyses showed there were varying degrees of population inbreeding and suggested that gene flow existed among its populations at one time. Three mutation models were also used to detect the bottleneck effect of reindeer population. The genetic variation of eight populations is relatively small. In addition, the clustering program STRUCTURE was used to analyse Aoluguya Reindeer population structure, to determine its optimal K and first time to analyse the phylogenetic status of Aoluguya Reindeer among other reindeer subspecies. It is recommended that the government establish a natural conservation area in Aoluguya Reindeer growing geography, forbade the trade and hunting of Aoluguya Reindeer, and strengthen the protection of this endangered species.

Transcatheter Closure of Bilateral Multiple Huge Pulmonary Arteriovenous Malformations with Homemade Double-Umbrella Occluders

International Nuclear Information System (INIS)

Zhong Hongshan; Xu Ke; Shao Haibo

2008-01-01

A 28-year-old man underwent successful transcatheter occlusion of three huge pulmonary arteriovenous malformations (PAVMs) using homemade double-umbrella occluders and stainless steel coils. Thoracic CT with three-dimensional reconstruction and pulmonary angiography were used for treatment planning and follow-up. The diameters of the feeding vessels were 11 mm, 13 mm, and 14 mm, respectively. This report demonstrates the novel design and utility of the double-umbrella occluder, an alternative tool for treatment of large PAVMs.

Orientation of aromatic residues in amyloid cores: Structural insights into prion fiber diversity

KAUST Repository

Reymer, Anna

2014-11-17

Structural conversion of one given protein sequence into different amyloid states, resulting in distinct phenotypes, is one of the most intriguing phenomena of protein biology. Despite great efforts the structural origin of prion diversity remains elusive, mainly because amyloids are insoluble yet noncrystalline and therefore not easily amenable to traditional structural-biology methods. We investigate two different phenotypic prion strains, weak and strong, of yeast translation termination factor Sup35 with respect to angular orientation of tyrosines using polarized light spectroscopy. By applying a combination of alignment methods the degree of fiber orientation can be assessed, which allows a relatively accurate determination of the aromatic ring angles. Surprisingly, the strains show identical average orientations of the tyrosines, which are evenly spread through the amyloid core. Small variations between the two strains are related to the local environment of a fraction of tyrosines outside the core, potentially reflecting differences in fibril packing.

Reduced Fragment Diversity for Alpha and Alpha-Beta Protein Structure Prediction using Rosetta.

Science.gov (United States)

Abbass, Jad; Nebel, Jean-Christophe

2017-01-01

Protein structure prediction is considered a main challenge in computational biology. The biannual international competition, Critical Assessment of protein Structure Prediction (CASP), has shown in its eleventh experiment that free modelling target predictions are still beyond reliable accuracy, therefore, much effort should be made to improve ab initio methods. Arguably, Rosetta is considered as the most competitive method when it comes to targets with no homologues. Relying on fragments of length 9 and 3 from known structures, Rosetta creates putative structures by assembling candidate fragments. Generally, the structure with the lowest energy score, also known as first model, is chosen to be the "predicted one". A thorough study has been conducted on the role and diversity of 3-mers involved in Rosetta's model "refinement" phase. Usage of the standard number of 3-mers - i.e. 200 - has been shown to degrade alpha and alpha-beta protein conformations initially achieved by assembling 9-mers. Therefore, a new prediction pipeline is proposed for Rosetta where the "refinement" phase is customised according to a target's structural class prediction. Over 8% improvement in terms of first model structure accuracy is reported for alpha and alpha-beta classes when decreasing the number of 3- mers. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Predicting acute aquatic toxicity of structurally diverse chemicals in fish using artificial intelligence approaches.

Science.gov (United States)

Singh, Kunwar P; Gupta, Shikha; Rai, Premanjali

2013-09-01

The research aims to develop global modeling tools capable of categorizing structurally diverse chemicals in various toxicity classes according to the EEC and European Community directives, and to predict their acute toxicity in fathead minnow using set of selected molecular descriptors. Accordingly, artificial intelligence approach based classification and regression models, such as probabilistic neural networks (PNN), generalized regression neural networks (GRNN), multilayer perceptron neural network (MLPN), radial basis function neural network (RBFN), support vector machines (SVM), gene expression programming (GEP), and decision tree (DT) were constructed using the experimental toxicity data. Diversity and non-linearity in the chemicals' data were tested using the Tanimoto similarity index and Brock-Dechert-Scheinkman statistics. Predictive and generalization abilities of various models constructed here were compared using several statistical parameters. PNN and GRNN models performed relatively better than MLPN, RBFN, SVM, GEP, and DT. Both in two and four category classifications, PNN yielded a considerably high accuracy of classification in training (95.85 percent and 90.07 percent) and validation data (91.30 percent and 86.96 percent), respectively. GRNN rendered a high correlation between the measured and model predicted -log LC50 values both for the training (0.929) and validation (0.910) data and low prediction errors (RMSE) of 0.52 and 0.49 for two sets. Efficiency of the selected PNN and GRNN models in predicting acute toxicity of new chemicals was adequately validated using external datasets of different fish species (fathead minnow, bluegill, trout, and guppy). The PNN and GRNN models showed good predictive and generalization abilities and can be used as tools for predicting toxicities of structurally diverse chemical compounds. Copyright © 2013 Elsevier Inc. All rights reserved.

Hybrid Organic-Inorganic Perovskites: Structural Diversity and Opportunities for Semiconductor Design

Science.gov (United States)

Mitzi, David

Photovoltaic (PV) devices based on three-dimensional perovskites, (Cs, MA, FA)Pb(I, Br)3 (MA =methylammonium, FA =formamidinium), have attracted substantial recent interest, because of the unprecedented rise in power conversion efficiency to values above 20%, which in turn is made possible by the near ideal band gap, strong optical absorption, high carrier mobilities, long minority carrier lifetimes, and relatively benign defects and grain boundaries for the absorbers. Some of the same properties that render these materials near-ideal for PV, also make them attractive for LED and other optoelectronic applications. Despite the high levels of device performance, the incorporation of the heavy metal lead, coupled with issues of device stability and electrical hysteresis pose challenges for commercializing these exciting technologies. This talk will provide a perspective on and discuss recent advances related to the broader perovskite family, focusing on the extraordinary structural/chemical diversity, including ability to control structural/electronic dimensionality, substitute on the organic cation, metal or halogen sites, and prospects of multi-functionality arising from separately engineered organic/inorganic structural components (e.g., see). Further exploration within this perovskite structural and chemical space offers exciting opportunities for future energy and electronic materials design. This work has been financially supported by the Office of Energy Efficiency and Renewable Energy (EERE), U.S. Dept. of Energy, under Award Number DE-EE0006712.

Genetic diversity and structure in semiwild and domesticated chiles (Capsicum annuum; Solanaceae) from Mexico.

Science.gov (United States)

Aguilar-Meléndez, Araceli; Morrell, Peter L; Roose, Mikeal L; Kim, Seung-Chul

2009-06-01

The chile of Mesoamerica, Capsicum annuum, is one of five domesticated chiles in the Americas. Among the chiles, it varies the most in size, form, and color of its fruits. Together with maize, C. annuum is one of the principal elements of the neotropical diets of Mesoamerican civilizations. Despite the great economic and cultural importance of C. annuum both worldwide and in Mexico, however, very little is known about its geographic origin and number of domestications. Here we sampled a total of 80 accessions from Mexico (58 semiwild and 22 domesticated) and examined nucleotide sequence diversity at three single- or low-copy nuclear loci, Dhn, G3pdh, and Waxy. Across the three loci, we found an average reduction of ca. 10% in the diversity of domesticates relative to semiwild chiles and geographic structure within Mexican populations. The Yucatan Peninsula contained a large number of haplotypes, many of which were unique, suggesting an important region of chile domestication and center of diversity. The present sampling of loci did not conclusively resolve the number and location of domestications, but several lines of evidence suggest multiple independent domestications from widely distributed progenitor populations.

Genetic diversity and population structure assessed by SSR and SNP markers in a large germplasm collection of grape

Science.gov (United States)

2013-01-01

Background The economic importance of grapevine has driven significant efforts in genomics to accelerate the exploitation of Vitis resources for development of new cultivars. However, although a large number of clonally propagated accessions are maintained in grape germplasm collections worldwide, their use for crop improvement is limited by the scarcity of information on genetic diversity, population structure and proper phenotypic assessment. The identification of representative and manageable subset of accessions would facilitate access to the diversity available in large collections. A genome-wide germplasm characterization using molecular markers can offer reliable tools for adjusting the quality and representativeness of such core samples. Results We investigated patterns of molecular diversity at 22 common microsatellite loci and 384 single nucleotide polymorphisms (SNPs) in 2273 accessions of domesticated grapevine V. vinifera ssp. sativa, its wild relative V. vinifera ssp. sylvestris, interspecific hybrid cultivars and rootstocks. Despite the large number of putative duplicates and extensive clonal relationships among the accessions, we observed high level of genetic variation. In the total germplasm collection the average genetic diversity, as quantified by the expected heterozygosity, was higher for SSR loci (0.81) than for SNPs (0.34). The analysis of the genetic structure in the grape germplasm collection revealed several levels of stratification. The primary division was between accessions of V. vinifera and non-vinifera, followed by the distinction between wild and domesticated grapevine. Intra-specific subgroups were detected within cultivated grapevine representing different eco-geographic groups. The comparison of a phenological core collection and genetic core collections showed that the latter retained more genetic diversity, while maintaining a similar phenotypic variability. Conclusions The comprehensive molecular characterization of our grape

Diversity of condensed tannin structures affects rumen in vitro methane production in sainfoin (Onobrychis viciifolia) accessions

NARCIS (Netherlands)

Hatew, B.; Hayot Carbonero, C.; Stringano, E.; Sales, L. F.; Smith, L. M J; Mueller-Harvey, I.; Hendriks, W. H.; Pellikaan, W. F.

2015-01-01

Sainfoin is a non-bloating temperate forage legume with a moderate-to-high condensed tannin (CT) content. This study investigated whether the diversity of sainfoin accessions in terms of CT structures and contents could be related to rumen in vitro gas and methane (CH4) production and fermentation

Genetic Diversity and Spatial Genetic Structure of an Epiphytic Bromeliad in Costa Rican Montane Secondary Forest Patches

NARCIS (Netherlands)

Cascante-Marín, A.; Oostermeijer, G.; Wolf, J.; Fuchs, E.J.

2014-01-01

Information on genetic variation and its distribution in tropical plant populations relies mainly on studies of ground-rooted species, while genetic information of epiphytic plants is still limited. Particularly, the effect of forest successional condition on genetic diversity and structure of

SPECIES DIVERSITY AND COMMUNITY STRUCTURE OF FRUIT-FEEDING BUTTERFLIES (LEPIDOPTERA: NYMPHALIDAE IN AN EASTERN AMAZONIAN FOREST

Directory of Open Access Journals (Sweden)

LUCAS PEREIRA MARTINS

Full Text Available ABSTRACT Deforestation has negative impacts on diversity and community patterns of several taxa. In the eastern Amazon, where much deforestation is predicted for the coming years, forests patches may be essential to maintain the local biodiversity. Despite increasing concerns about the conservation of threatened areas, few studies have been performed to analyze the communities of diversified groups, such as insects, in the eastern Amazon. Here, we investigated species diversity and community structure of fruit-feeding butterflies, a well-known bioindicator group, in a threatened remnant of an eastern Amazonian forest located on Maranhão Island, northeastern Brazil. Fruit-feeding butterflies were sampled monthly for one year. Diversity and evenness indices, richness estimators, rarefaction curve, and rank-abundance plot were used to describe community structure in the study area. We captured 529 fruit-feeding butterflies in four subfamilies, 23 genera and 34 species. The three most abundant species, Hamadryas februa, Hamadryas feronia, and Hermeuptychia cf. atalanta are indicators of disturbed habitats and represented more than half of the collected individuals. Richness estimators revealed that between 87 and 94% of the fruit-feeding butterfly species were sampled, suggesting few additional records would be made for the area. Our results indicate that human-caused disturbances have altered local community patterns and provide baseline data for future research in threatened regions of the eastern Amazon.

Relationship between land use pattern and the structure and diversity of soil meso-micro arthropod community.

Science.gov (United States)

Zhang, Limin; Zhang, Xueping; Cui, Wei

2014-05-01

Soil arthropod communities can provide valuable information regarding the impacts of human disturbances on ecosystem structure. Our study evaluated the structure, composition and diversity of soil meso-micro arthropod communities, in six different vegetation types and assessed the impacts of human activity. A completely randomized design, including 3 replicates from 6 sites (mowing steppe, natural grassland, severe degradation grassland, farmland, artificial shelter forest, and wetland) was used. Soil samples from the depth of 0 to 20 cm were collected during May, July, and September 2007. Soil meso-micro arthropod were separated using the Tullgren funnels method, and were identified and counted. Soil pH value, organic matter, and total nitrogen were measured in topsoil (0-20 cm) from each site. A total of 5,602 soil meso-micro arthropod individuals were collected, representing 4 classes, 14 orders, and 57 families. Most soil arthropods were widely distributed; however, some species appeared to be influenced by environment variables, and might serve as bioindicators of adverse human impacts. Canonical correspondence analysis indicated the soil arthropod distribution in the severely degraded grassland, mowing steppe, farmland, and shelter forest differed from the natural grassland. Arthropod density and diversity were greatest in May, and the forestland community was the most stable. Because of the vital role soil arthropods have in maintaining a healthy ecosystem, mechanisms to maintain their abundance and diversity should be further evaluated.

Genetic diversity and structure of domestic cavy (Cavia porcellus populations from smallholder farms in southern Cameroon

Directory of Open Access Journals (Sweden)

Basengere Ayagirwe

2017-09-01

Full Text Available Although domestic cavies are widely used in sub-Saharan Africa as a source of meat and income, there are only a few studies of their population structure and genetic relatedness. This seminal study was designed with the main objective to assess the genetic diversity and determine the population structure of cavy populations from Cameroon to guide the development of a cavy improvement program. Sixteen microsatellite markers were used to genotype 109 individuals from five cavy populations (Wouri, Moungo and Nkongsamba in the Littoral region, and Mémé and Fako in the Southwest region of Cameroon. Twelve markers worked in the five populations with a total of 17 alleles identified, with a range of 2.9 to 4.0 alleles per locus. Observed heterozygosity (from 0.022 to 0.277 among populations was lower than expected heterozygosity (from 0.42 to 0.54. Inbreeding rates between individuals of the populations and between individuals in each population were 59.3% and 57.2%, respectively, against a moderate differentiation rate of 4.9%. All the tested loci deviated from Hardy-Weinberg equilibrium, except for locus 3. Genetic distances between populations were small (from 0.008 to 0.277, with a high rate of variability among individuals within each population (54.4%. Three distinct genetic groups were structured. This study has shown that microsatellites are useful for the genetic characterization of cavy populations in Cameroon and that the populations investigated have sufficient genetic diversity that can be used to be deployed as a basis for weight, prolificacy and disease resistance improvement. The genetic of diversity in Southern Cameroon is wide and constitute an opportunity for cavy breeding program.

PRS: PERSONNEL RECOMMENDATION SYSTEM FOR HUGE DATA ANALYSIS USING PORTER STEMMER

Directory of Open Access Journals (Sweden)

T N Chiranjeevi

2016-04-01

Full Text Available Personal recommendation system is one which gives better and preferential recommendation to the users to satisfy their personalized requirements such as practical applications like Webpage Preferences, Sport Videos preferences, Stock selection based on price, TV preferences, Hotel preferences, books, Mobile phones, CDs and various other products now use recommender systems. The existing Pearson Correlation Coefficient (PCC and item-based algorithm using PCC, are called as UPCC and IPCC respectively. These systems are mainly based on only the rating services and does not consider the user personal preferences, they simply just give the result based on the ratings. As the size of data increases it will give the recommendations based on the top rated services and it will miss out most of user preferences. These are main drawbacks in the existing system which will give same results to the users based on some evaluations and rankings or rating service, they will neglect the user preferences and necessities. To address this problem we propose a new approach called, Personnel Recommendation System (PRS for huge data analysis using Porter Stemmer to solve the above challenges. In the proposed system it provides a personalized service recommendation list to the users and recommends the most useful services to the users which will increase the accuracy and efficiency in searching better services. Particularly, a set of suggestions or keywords are provided to indicate user preferences and we used Collaborative Filtering and Porter Stemmer algorithm which gives a suitable recommendations to the users. In real, the broad experiments are conducted on the huge database which is available in real world, and outcome shows that our proposed personal recommender method extensively improves the precision and efficiency of service recommender system over the KASR method. In our approach mainly consider the user preferences so it will not miss out the any of the data

Process control upgrades yield huge operational improvements

International Nuclear Information System (INIS)

Fitzgerald, W.V.

2001-01-01

Most nuclear plants in North America were designed and built in the late 60 and 70. The regulatory nature of this industry over the years has made design changes at the plant level difficult, if not impossible, to implement. As a result, many plants in this world region have been getting by on technology that is over 40 years behind the times. What this translates into is that the plants have not been able to take advantage of the huge technology gains that have been made in process control during this period. As a result, most of these plants are much less efficient and productive than they could be. One particular area of the plant that is receiving a lot of attention is the feedwater heaters. These systems were put in place to improve efficiency, but most are not operating correctly. This paper will present a case study where one progressive mid-western utility decided that enough was enough and implemented a process control audit of their heater systems. The audit clearly pointed out the existing problems with the current process control system. It resulted in a proposal for the implementation of a state of the art, digital distributed process control system for the heaters along with a complete upgrade of the level controls and field devices that will stabilize heater levels, resulting in significant efficiency gains and lower maintenance bills. Overall the payback period for this investment should be less than 6 months and the plant is now looking for more opportunities that can provide even bigger gains. (author)

Bacterial community structure and diversity responses to the direct revegetation of an artisanal zinc smelting slag after 5 years.

Science.gov (United States)

Luo, Youfa; Wu, Yonggui; Wang, Hu; Xing, Rongrong; Zheng, Zhilin; Qiu, Jing; Yang, Lian

2018-05-01

This comparative field study examined the responses of bacterial community structure and diversity to the revegetation of zinc (Zn) smelting waste slag with eight plant species after 5 years. The microbial community structure of waste slag with and without vegetation was evaluated using high-throughput sequencing. The physiochemical properties of Zn smelting slag after revegetation with eight plant rhizospheres for 5 years were improved compared to those of bulk slag. Revegetation significantly increased the microbial community diversity in plant rhizospheres, and at the phylum level, Proteobacteria, Acidobacteria, and Bacteroidetes were notably more abundant in rhizosphere slags than those in bulk waste slag. Additionally, revegetation increased the relative abundance of plant growth-promoting rhizobacteria such as Flavobacterium, Streptomyces, and Arthrobacter as well as symbiotic N 2 fixers such as Bradyrhizobium. Three dominant native plant species (Arundo donax, Broussonetia papyrifera, and Robinia pseudoacacia) greatly increased the quality of the rhizosphere slags. Canonical correspondence analysis showed that the differences in bacterial community structure between the bulk and rhizosphere slags were explained by slag properties, i.e., pH, available copper (Cu) and lead (Pb), moisture, available nitrogen (N), phosphorus (P), and potassium (K), and organic matter (OM); however, available Zn and cadmium (Cd) contents were the slag parameters that best explained the differences between the rhizosphere communities of the eight plant species. The results suggested that revegetation plays an important role in enhancing bacterial community abundance and diversity in rhizosphere slags and that revegetation may also regulate microbiological properties and diversity mainly through changes in heavy metal bioavailability and physiochemical slag characteristics.

Huge pelvic parachordoma: fine needle aspiration cytology and histological differential diagnosis

Directory of Open Access Journals (Sweden)

Mona A. Kandil

2012-10-01

Full Text Available Parachordoma is an extremely rare soft tissue tumor of unknown lineage. Parachordoma develops most often on the extremities. Only 2 cases have been reported as pelvic parachordoma. A 46-year old Egyptian woman with a huge painful pelvic mass was found to have a parachordoma with ectopic pelvic right kidney. There is only one report in the literature of fine needle aspiration cytology in this setting. The microscopic picture of parachordoma is not new to pathologists but the gross picture of this rare tumor has not previously been published; not even in the World Health Organization classification of soft tissues tumors. Diagnosis was confirmed by immuno-histochemistry. The patient is in good clinical condition without any evidence of recurrence or metastasis after 84 months of follow up.

High genetic diversity and fine-scale spatial structure in the marine flagellate Oxyrrhis marina (Dinophyceae uncovered by microsatellite loci.

Directory of Open Access Journals (Sweden)

Chris D Lowe

2010-12-01

Full Text Available Free-living marine protists are often assumed to be broadly distributed and genetically homogeneous on large spatial scales. However, an increasing application of highly polymorphic genetic markers (e.g., microsatellites has provided evidence for high genetic diversity and population structuring on small spatial scales in many free-living protists. Here we characterise a panel of new microsatellite markers for the common marine flagellate Oxyrrhis marina. Nine microsatellite loci were used to assess genotypic diversity at two spatial scales by genotyping 200 isolates of O. marina from 6 broad geographic regions around Great Britain and Ireland; in one region, a single 2 km shore line was sampled intensively to assess fine-scale genetic diversity. Microsatellite loci resolved between 1-6 and 7-23 distinct alleles per region in the least and most variable loci respectively, with corresponding variation in expected heterozygosities (H(e of 0.00-0.30 and 0.81-0.93. Across the dataset, genotypic diversity was high with 183 genotypes detected from 200 isolates. Bayesian analysis of population structure supported two model populations. One population was distributed across all sampled regions; the other was confined to the intensively sampled shore, and thus two distinct populations co-occurred at this site. Whilst model-based analysis inferred a single UK-wide population, pairwise regional F(ST values indicated weak to moderate population sub-division (0.01-0.12, but no clear correlation between spatial and genetic distance was evident. Data presented in this study highlight extensive genetic diversity for O. marina; however, it remains a substantial challenge to uncover the mechanisms that drive genetic diversity in free-living microorganisms.

Assessment of variations in taxonomic diversity, forest structure, and aboveground biomass using remote sensing along an altitudinal gradient in tropical montane forest of Costa Rica

Science.gov (United States)

Robinson, C. M.; Saatchi, S. S.; Clark, D.; Fricker, G. A.; Wolf, J.; Gillespie, T. W.; Rovzar, C. M.; Andelman, S.

2012-12-01

This research sought to understand how alpha and beta diversity of plants vary and relate to the three-dimensional vegetation structure and aboveground biomass along environmental gradients in the tropical montane forests of Braulio Carrillo National Park in Costa Rica. There is growing evidence that ecosystem structure plays an important role in defining patterns of species diversity and along with abiotic factors (climate and edaphic) control the phenotypic and functional variations across landscapes. It is well documented that strong subdivisions at local and regional scales are found mainly on geologic or climate gradients. These general determinants of biodiversity are best demonstrated in regions with natural gradients such as tropical montane forests. Altitudinal gradients provide a landscape scale changes through variations in topography, climate, and edaphic conditions on which we tested several theoretical and biological hypotheses regarding drivers of biodiversity. The study was performed by using forest inventory and botanical data from nine 1-ha plots ranging from 100 m to 2800 m above sea level and remote sensing data from airborne lidar and radar sensors to quantify variations in forest structure. In this study we report on the effectiveness of relating patterns of tree taxonomic alpha diversity to three-dimensional structure of a tropical montane forest using lidar and radar observations of forest structure and biomass. We assessed alpha and beta diversity at the species, genus, and family levels utilizing datasets provided by the Terrestrial Ecology Assessment and Monitoring (TEAM) Network. Through the comparison to active remote sensing imagery, our results show that there is a strong relationship between forest 3D-structure, and alpha and beta diversity controlled by variations in abiotic factors along the altitudinal gradient. Using spatial analysis with the aid of remote sensing data, we find distinct patterns along the environmental gradients

Structural Diversity of Streptococcal Mutans Synthesized under Different Culture and Environmental Conditions and Its Effect on Mutanase Synthesis

Directory of Open Access Journals (Sweden)

Katarzyna Próchniak

2012-10-01

Full Text Available Streptococcal mutans synthesized under different conditions by growing cultures or by their glucosyltransferases were shown to exhibit a great structural and property diversity. Culturing and environmental factors causing structural differences in mutans were specified. All of the obtained biopolymers (76 samples were water-insoluble and most of them (72 had a structure with a predominance of α-(1→3-linked glucose (i.e., the content of α-(1→3-linkages in the glucan was always higher than 50%, but did not exceed 76%. An exception were four glucans containing more than 50% of α-(1→6-sequences. In these structurally unique mutans, the ratio of α-(1→3- to α-(1→6-bonds ranged from 0.75 to 0.97. Aside from one polymer, all others had a heavily branched structures and differed in the number of α-(1→3, α-(1→6, and α-(1→3,6 linkages and their mutual proportion. The induction of mutanase production in shaken flask cultures of Trichoderma harzianum by the structurally diverse mutans resulted in enzyme activities ranging from 0.144 to 1.051 U/mL. No statistical correlation was found between the total percentage content of α-(1→3-linkages in the α-glucan and mutanase activity. Thus, despite biosynthetic differences causing structural variation in the mutans, it did not matter which mutan structures were used to induce mutanase production.

Genetic diversity and structure analysis in wild and landraces of barley from Jordan by using ISJ markers

International Nuclear Information System (INIS)

Baloch, A. W.; Balogh, M. J.; Baloch, M.; Baloch, I. A.

2016-01-01

The present experiment was carried out to estimate genetic diversity and genetic structure in cultivated and wild barley populations collected from Jordan which is considered as primary gene pool of barley. In a total, 94 cultivated barley accessions composed of 4 populations and 52 wild barley accessions consisted of 3 populations were used for genetic analysis using 7 Intron Splice Junction (ISJ) markers. The genetic diversity index (He) of cultivated barley ranged between 0.049 and 0.060; whereas that of wild barley populations ranged between 0.084 and 0.146, suggesting that wild resources of barley harbored greater genetic diversity than its domesticated counterpart, reflecting that barley domestication occurred with genetic bottleneck. Analysis of molecular variance showed high genetic variations among rather than within populations, referring that high genetic differentiation of barley populations caused by genetic and geographical separation of the populations in the harsh growing conditions of Fertile Crescent. Principal coordinate, clustering and structure analysis not only separated cultivated and wild barley, but also each single population, showing their genetic basis and original sample site. The obtained Results also revealed that there is lesser genetic communication between cultivated and wild barley under natural environments. The current findings can better be exploited for collection and utilization of plant germplasms. (author)

Genetic diversity and genetic structure of the striped field mouse Apodemus agrarius coreae (Muridae, Rodentia) in Korea.

Science.gov (United States)

Kim, Hye Ri; Park, Yung Chul

2015-11-10

The aim of this study was to investigate the genetic diversity and genetic structure of the striped field mouse Apodemus agrarius coreae in Korea. The Korean A. a. coreae is characterized by high levels of haplotype diversity (Hd=0.967) and low levels of nucleotide diversity (π=0.00683). Haplogroup 1 is well separated from the haplotypes of the neighboring regions of the Korean Peninsula, while the other haplogroups are closely related to those from the Russian Far East. Thus, further investigations are required to confirm the validity of the subspecies status of A. a. coreae by implementing additional morphological characters as well as genetic data from the populations present in the Korean Peninsula and its neighboring countries. Haplogroup 1 includes most Korean haplotypes and forms a star-like haplotype network structure, which reveals relatively low levels of sequence divergence and high frequency of unique mutations (only few mutations are shared in most of the haplotype nodes). The results indicate that the haplotypes of Haplogroup 1 might have experienced population expansion since their migration into Korea, which was further corroborated with negative results of neutrality tests for Korean population of A. a. coreae. Copyright © 2015. Published by Elsevier B.V.

Molecular diversity and population structure of the forage grass Hemarthria compressa (Poaceae) in south China based on SRAP markers.

Science.gov (United States)

Huang, L-K; Zhang, X-Q; Xie, W-G; Zhang, J; Cheng, L; Yan, H D

2012-08-16

Hemarthria compressa is one of the most important and widely utilized forage crops in south China, owing to its high forage yield and capability of adaptation to hot and humid conditions. We examined the population structure and genetic variation within and among 12 populations of H. compressa in south China using sequence-related amplified polymorphism (SRAP) markers. High genetic diversity was found in these samples [percentage polymorphic bands (PPB) = 82.21%, Shannon's diversity index (I) = 0.352]. However, there was relatively low level of genetic diversity at the population level (PPB = 29.17%, I = 0.155). A high degree of genetic differentiation among populations was detected based on other measures and molecular markers (Nei's genetic diversity analysis: G(ST) = 54.19%; AMOVA analysis: F(ST) = 53.35%). The SRAP markers were found to be more efficient than ISSR markers for evaluating population diversity. Based on these findings, we propose changes in sampling strategies for appraising and utilizing the genetic resources of this species.

Extensive genetic diversity, unique population structure and evidence of genetic exchange in the sexually transmitted parasite Trichomonas vaginalis.

Directory of Open Access Journals (Sweden)

Melissa D Conrad

Full Text Available Trichomonas vaginalis is the causative agent of human trichomoniasis, the most common non-viral sexually transmitted infection world-wide. Despite its prevalence, little is known about the genetic diversity and population structure of this haploid parasite due to the lack of appropriate tools. The development of a panel of microsatellite makers and SNPs from mining the parasite's genome sequence has paved the way to a global analysis of the genetic structure of the pathogen and association with clinical phenotypes.Here we utilize a panel of T. vaginalis-specific genetic markers to genotype 235 isolates from Mexico, Chile, India, Australia, Papua New Guinea, Italy, Africa and the United States, including 19 clinical isolates recently collected from 270 women attending New York City sexually transmitted disease clinics. Using population genetic analysis, we show that T. vaginalis is a genetically diverse parasite with a unique population structure consisting of two types present in equal proportions world-wide. Parasites belonging to the two types (type 1 and type 2 differ significantly in the rate at which they harbor the T. vaginalis virus, a dsRNA virus implicated in parasite pathogenesis, and in their sensitivity to the widely-used drug, metronidazole. We also uncover evidence of genetic exchange, indicating a sexual life-cycle of the parasite despite an absence of morphologically-distinct sexual stages.Our study represents the first robust and comprehensive evaluation of global T. vaginalis genetic diversity and population structure. Our identification of a unique two-type structure, and the clinically relevant phenotypes associated with them, provides a new dimension for understanding T. vaginalis pathogenesis. In addition, our demonstration of the possibility of genetic exchange in the parasite has important implications for genetic research and control of the disease.

Extensive genetic diversity, unique population structure and evidence of genetic exchange in the sexually transmitted parasite Trichomonas vaginalis.

Science.gov (United States)

Conrad, Melissa D; Gorman, Andrew W; Schillinger, Julia A; Fiori, Pier Luigi; Arroyo, Rossana; Malla, Nancy; Dubey, Mohan Lal; Gonzalez, Jorge; Blank, Susan; Secor, William E; Carlton, Jane M

2012-01-01

Trichomonas vaginalis is the causative agent of human trichomoniasis, the most common non-viral sexually transmitted infection world-wide. Despite its prevalence, little is known about the genetic diversity and population structure of this haploid parasite due to the lack of appropriate tools. The development of a panel of microsatellite makers and SNPs from mining the parasite's genome sequence has paved the way to a global analysis of the genetic structure of the pathogen and association with clinical phenotypes. Here we utilize a panel of T. vaginalis-specific genetic markers to genotype 235 isolates from Mexico, Chile, India, Australia, Papua New Guinea, Italy, Africa and the United States, including 19 clinical isolates recently collected from 270 women attending New York City sexually transmitted disease clinics. Using population genetic analysis, we show that T. vaginalis is a genetically diverse parasite with a unique population structure consisting of two types present in equal proportions world-wide. Parasites belonging to the two types (type 1 and type 2) differ significantly in the rate at which they harbor the T. vaginalis virus, a dsRNA virus implicated in parasite pathogenesis, and in their sensitivity to the widely-used drug, metronidazole. We also uncover evidence of genetic exchange, indicating a sexual life-cycle of the parasite despite an absence of morphologically-distinct sexual stages. Our study represents the first robust and comprehensive evaluation of global T. vaginalis genetic diversity and population structure. Our identification of a unique two-type structure, and the clinically relevant phenotypes associated with them, provides a new dimension for understanding T. vaginalis pathogenesis. In addition, our demonstration of the possibility of genetic exchange in the parasite has important implications for genetic research and control of the disease.

Plant-associated microbiomes in arid lands: diversity, ecology and biotechnological potential

KAUST Repository

Soussi, Asma

2015-08-28

Background: Aridification is a worldwide serious threat directly affecting agriculture and crop production. In arid and desert areas, it has been found that microbial diversity is huge, built of microorganisms able to cope with the environmental harsh conditions by developing adaptation strategies. Plants growing in arid lands or regions facing prolonged abiotic stresses such as water limitation and salt accumulation have also developed specific physiological and molecular stress responses allowing them to thrive under normally unfavorable conditions. Scope: Under such extreme selection pressures, special root-associated bacterial assemblages, endowed with capabilities of plant growth promotion (PGP) and extremophile traits, are selected by the plants. In this review, we provide a general overview on the microbial diversity in arid lands and deserts versus specific microbial assemblages associated with plants. The ecological drivers that shape this diversity, how plant-associated microbiomes are selected, and their biotechnological potential are discussed. Conclusions: Selection and recruitment of the plant associated bacterial assemblages is mediated by the combination of the bio-pedo-agroclimatic conditions and the plant species or varieties. Diversity and functional redundancy of these associated PGPR makes them very active in supporting plant improvement, health and resistance to drought, salt and related stresses. Implementing proper biotechnological applications of the arid and desert-adapted PGPR constitute the challenge to be raised.

Structural determinants of phenotypic diversity and replication rate of human prions.

Directory of Open Access Journals (Sweden)

Jiri G Safar

2015-04-01

Full Text Available The infectious pathogen responsible for prion diseases is the misfolded, aggregated form of the prion protein, PrPSc. In contrast to recent progress in studies of laboratory rodent-adapted prions, current understanding of the molecular basis of human prion diseases and, especially, their vast phenotypic diversity is very limited. Here, we have purified proteinase resistant PrPSc aggregates from two major phenotypes of sporadic Creutzfeldt-Jakob disease (sCJD, determined their conformational stability and replication tempo in vitro, as well as characterized structural organization using recently emerged approaches based on hydrogen/deuterium (H/D exchange coupled with mass spectrometry. Our data clearly demonstrate that these phenotypically distant prions differ in a major way with regard to their structural organization, both at the level of the polypeptide backbone (as indicated by backbone amide H/D exchange data as well as the quaternary packing arrangements (as indicated by H/D exchange kinetics for histidine side chains. Furthermore, these data indicate that, in contrast to previous observations on yeast and some murine prion strains, the replication rate of sCJD prions is primarily determined not by conformational stability but by specific structural features that control the growth rate of prion protein aggregates.

The influence of vegetation structure on spider species richness, diversity and community organization in the Apšuciems calcareous fen, Latvia

Energy Technology Data Exchange (ETDEWEB)

Štokmane, M.; Spuņģis, V.

2016-07-01

Calcareous fens are considered to be among the most threatened ecosystems of Europe. They are also one of the most diverse habitats as they support an incredibly rich and diverse range of plant and animal species. However, in spite of their diversity, calcareous fens are still poorly investigated, especially when referring to fen invertebrates, such as spiders. Because spiders are good bioindicators, knowledge of their ecology in rare and threatened habitats is of interest. The aim of this study was to document the composition and diversity of spider species, families and foraging guilds in the ground– and grass–layers of the Apšuciems calcareous fen, and to evaluate the influence of vegetation structure on spider community organization. In summer 2012, we collected ground–dwelling spiders using pitfall traps and grass–dwelling spiders using sweep–netting. A total of 2,937 spider individuals belonging to 19 families and 80 species was collected in the Apšuciems fen. Our results indicate that spider species and families tend to be stratified across the vertical structure of the habitat; the spider composition in the ground stratum differed from that in the grass stratum. On the contrary, however, the spider foraging guild structure between the ground–layer and the grass–layer was similar. Each of the two studied strata presented similar guilds in similar proportions. Our results also showed that spider composition differed considerably between fen parts and that much of this variability could be explained by the architectural properties of the habitat. More diverse vegetation generally supported a higher number of spider species. (Author)

Genetic Diversity, Population Structure, and Heritability of Fruit Traits in Capsicum annuum

Science.gov (United States)

Naegele, Rachel P.; Mitchell, Jenna; Hausbeck, Mary K.

2016-01-01

Cultivated pepper (Capsicum annuum) is a phenotypically diverse species grown throughout the world. Wild and landrace peppers are typically small-fruited and pungent, but contain many important traits such as insect and disease resistance. Cultivated peppers vary dramatically in size, shape, pungency, and color, and often lack resistance traits. Fruit characteristics (e.g. shape and pericarp thickness) are major determinants for cultivar selection, and their association with disease susceptibility can reduce breeding efficacy. This study evaluated a diverse collection of peppers for mature fruit phenotypic traits, correlation among fruit traits and Phytophthora fruit rot resistance, genetic diversity, population structure, and trait broad sense heritability. Significant differences within all fruit phenotype categories were detected among pepper lines. Fruit from Europe had the thickest pericarp, and fruit from Ecuador had the thinnest. For fruit shape index, fruit from Africa had the highest index, while fruit from Europe had the lowest. Five genetic clusters were detected in the pepper population and were significantly associated with fruit thickness, end shape, and fruit shape index. The genetic differentiation between clusters ranged from little to very great differentiation when grouped by the predefined categories. Broad sense heritability for fruit traits ranged from 0.56 (shoulder height) to 0.98 (pericarp thickness). When correlations among fruit phenotypes and fruit disease were evaluated, fruit shape index was negatively correlated with pericarp thickness, and positively correlated with fruit perimeter. Pepper fruit pericarp, perimeter, and width had a slight positive correlation with Phytophthora fruit rot, whereas fruit shape index had a slight negative correlation. PMID:27415818

Diversity, Host Specialization, and Geographic Structure of Filarial Nematodes Infecting Malagasy Bats.

Science.gov (United States)

Ramasindrazana, Beza; Dellagi, Koussay; Lagadec, Erwan; Randrianarivelojosia, Milijaona; Goodman, Steven M; Tortosa, Pablo

2016-01-01

We investigated filarial infection in Malagasy bats to gain insights into the diversity of these parasites and explore the factors shaping their distribution. Samples were obtained from 947 individual bats collected from 52 sites on Madagascar and representing 31 of the 44 species currently recognized on the island. Samples were screened for the presence of micro- and macro-parasites through both molecular and morphological approaches. Phylogenetic analyses showed that filarial diversity in Malagasy bats formed three main groups, the most common represented by Litomosa spp. infecting Miniopterus spp. (Miniopteridae); a second group infecting Pipistrellus cf. hesperidus (Vespertilionidae) embedded within the Litomosoides cluster, which is recognized herein for the first time from Madagascar; and a third group composed of lineages with no clear genetic relationship to both previously described filarial nematodes and found in M. griveaudi, Myotis goudoti, Neoromicia matroka (Vespertilionidae), Otomops madagascariensis (Molossidae), and Paratriaenops furculus (Hipposideridae). We further analyzed the infection rates and distribution pattern of Litomosa spp., which was the most diverse and prevalent filarial taxon in our sample. Filarial infection was disproportionally more common in males than females in Miniopterus spp., which might be explained by some aspect of roosting behavior of these cave-dwelling bats. We also found marked geographic structure in the three Litomosa clades, mainly linked to bioclimatic conditions rather than host-parasite associations. While this study demonstrates distinct patterns of filarial nematode infection in Malagasy bats and highlights potential drivers of associated geographic distributions, future work should focus on their alpha taxonomy and characterize arthropod vectors.

Diversity, Host Specialization, and Geographic Structure of Filarial Nematodes Infecting Malagasy Bats.

Directory of Open Access Journals (Sweden)

Beza Ramasindrazana

Full Text Available We investigated filarial infection in Malagasy bats to gain insights into the diversity of these parasites and explore the factors shaping their distribution. Samples were obtained from 947 individual bats collected from 52 sites on Madagascar and representing 31 of the 44 species currently recognized on the island. Samples were screened for the presence of micro- and macro-parasites through both molecular and morphological approaches. Phylogenetic analyses showed that filarial diversity in Malagasy bats formed three main groups, the most common represented by Litomosa spp. infecting Miniopterus spp. (Miniopteridae; a second group infecting Pipistrellus cf. hesperidus (Vespertilionidae embedded within the Litomosoides cluster, which is recognized herein for the first time from Madagascar; and a third group composed of lineages with no clear genetic relationship to both previously described filarial nematodes and found in M. griveaudi, Myotis goudoti, Neoromicia matroka (Vespertilionidae, Otomops madagascariensis (Molossidae, and Paratriaenops furculus (Hipposideridae. We further analyzed the infection rates and distribution pattern of Litomosa spp., which was the most diverse and prevalent filarial taxon in our sample. Filarial infection was disproportionally more common in males than females in Miniopterus spp., which might be explained by some aspect of roosting behavior of these cave-dwelling bats. We also found marked geographic structure in the three Litomosa clades, mainly linked to bioclimatic conditions rather than host-parasite associations. While this study demonstrates distinct patterns of filarial nematode infection in Malagasy bats and highlights potential drivers of associated geographic distributions, future work should focus on their alpha taxonomy and characterize arthropod vectors.

Insights into the genetic structure and diversity of 38 South Asian Indians from deep whole-genome sequencing.

Science.gov (United States)

Wong, Lai-Ping; Lai, Jason Kuan-Han; Saw, Woei-Yuh; Ong, Rick Twee-Hee; Cheng, Anthony Youzhi; Pillai, Nisha Esakimuthu; Liu, Xuanyao; Xu, Wenting; Chen, Peng; Foo, Jia-Nee; Tan, Linda Wei-Lin; Koo, Seok-Hwee; Soong, Richie; Wenk, Markus Rene; Lim, Wei-Yen; Khor, Chiea-Chuen; Little, Peter; Chia, Kee-Seng; Teo, Yik-Ying

2014-05-01

South Asia possesses a significant amount of genetic diversity due to considerable intergroup differences in culture and language. There have been numerous reports on the genetic structure of Asian Indians, although these have mostly relied on genotyping microarrays or targeted sequencing of the mitochondria and Y chromosomes. Asian Indians in Singapore are primarily descendants of immigrants from Dravidian-language-speaking states in south India, and 38 individuals from the general population underwent deep whole-genome sequencing with a target coverage of 30X as part of the Singapore Sequencing Indian Project (SSIP). The genetic structure and diversity of these samples were compared against samples from the Singapore Sequencing Malay Project and populations in Phase 1 of the 1,000 Genomes Project (1 KGP). SSIP samples exhibited greater intra-population genetic diversity and possessed higher heterozygous-to-homozygous genotype ratio than other Asian populations. When compared against a panel of well-defined Asian Indians, the genetic makeup of the SSIP samples was closely related to South Indians. However, even though the SSIP samples clustered distinctly from the Europeans in the global population structure analysis with autosomal SNPs, eight samples were assigned to mitochondrial haplogroups that were predominantly present in Europeans and possessed higher European admixture than the remaining samples. An analysis of the relative relatedness between SSIP with two archaic hominins (Denisovan, Neanderthal) identified higher ancient admixture in East Asian populations than in SSIP. The data resource for these samples is publicly available and is expected to serve as a valuable complement to the South Asian samples in Phase 3 of 1 KGP.

Low genetic diversity and intrapopulation spatial genetic structure of the Atlantic Forest tree, Esenbeckia leiocarpa Engl. (Rutaceae

Directory of Open Access Journals (Sweden)

G. Forti

2014-12-01

Full Text Available Studies on population genetics are the key to designing effective in situ management plans for tree species, in particular, those subjected to pressure from anthropogenic processes, such as forest fragmentation and logging. To investigate genetic diversity, inbreeding and intrapopulation spatial genetic structure (SGS in a fragmented population of the insect-pollinated tropical tree, Esenbeckia leiocarpa, we developed specific microsatellite markers for this species and mapped and sampled 100 individuals in a forest plot. Two issues were addressed in particular: (i the level of genetic diversity, inbreeding and effective population size, (ii whether intrapopulation spatial genetic structure exists. Among the 14 loci developed, we only used the three that presented polymorphism to estimate the genetic parameters. Genetic diversity was low, whereby the average number of alleles per locus (A was 3.3 and observed (H0 and expected heterozygosities (He were 0.336 and 0.298, respectively. The average fixation index was significantly higher than zero (F = 0.112, suggesting inbreeding. Significant SGS was found up to 7 m and between 31 to 38 m, indicating that trees growing within these distances may be related. Estimates of the effective population size indicated that the 100 sampled trees correspond to 14 individuals that are neither related nor inbred. Our results suggest that the microsatellite markers developed in this study are suitable for studies on geneticdiversity and structure, mating systems, gene flow and SGS in this species.

Diversity and genetic structure of the Mexican endemic epiphyte Tillandsia achyrostachys E. Morr. ex Baker var. achyrostachys (Bromeliaceae).

Science.gov (United States)

González-Astorga, Jorge; Cruz-Angón, Andrea; Flores-Palacios, Alejandro; Vovides, Andrew P

2004-10-01

The monoecious, bird-pollinated epiphytic Tillandsia achyrostachys E. Morr. ex Baker var. achyrostachys is an endemic bromeliad of the tropical dry forests of Mexico with clonal growth. In the Sierra de Huautla Natural Reserve this species shows a host preference for Bursera copallifera (Sessé & Moc ex. DC) Bullock. As a result of deforestation in the study area, B. copallifera has become a rare tree species in the remaining forest patches. This human-induced disturbance has directly affected the population densities of T. achyrostachys. In this study the genetic consequences of habitat fragmentation were assessed by comparing the genetic diversity, gene flow and genetic differentiation in six populations of T. achyrostachys in the Sierra de Huautla Natural Reserve, Mexico. Allozyme electrophoresis of sixteen loci (eleven polymorphic and five monomorphic) were used. The data were analysed with standard statistical approximations for obtaining diversity, genetic structure and gene flow. Genetic diversity and allelic richness were: HE = 0.21 +/- 0.02, A = 1.86 +/- 0.08, respectively. F-statistics revealed a deficiency of heterozygous plants in all populations (Fit = 0.65 +/- 0.02 and Fis = 0.43 +/- 0.06). Significant genetic differentiation between populations was detected (Fst = 0.39 +/- 0.07). Average gene flow between pairs of populations was relatively low and had high variation (Nm = 0.46 +/- 0.21), which denotes a pattern of isolation by distance. The genetic structure of populations of T. achyrostachys suggests that habitat fragmentation has reduced allelic richness and genetic diversity, and increased significant genetic differentiation (by approx. 40 %) between populations. The F-statistic values (>0) and the level of gene flow found suggest that habitat fragmentation has broken up the former population structure. In this context, it is proposed that the host trees of T. achyrostachys should be considered as a conservation priority, since they represent the

Huge residual resistivity in the quantum critical region of CeAgSb2

International Nuclear Information System (INIS)

Nakashima, Miho; Kirita, Shingo; Asai, Rihito; Kobayashi, Tatsuo C; Okubo, Tomoyuki; Yamada, Mineko; Thamizhavel, Arumugam; Inada, Yoshihiko; Settai, Rikio; Galatanu, Andre; Yamamoto, Etsuji; Ebihara, Takao; Onuki, Yoshichika

2003-01-01

We have studied the effect of pressure on the electrical resistivity of a high-quality single crystal CeAgSb 2 which has a small net ferromagnetic moment of 0.4μ B /Ce. The magnetic ordering temperature T ord = 9.7 K decreases with increasing pressure p and disappears at a critical pressure p c ≅ 3.3 GPa. The residual resistivity, which is close to zero up to 3 GPa, increases steeply above 3 GPa, reaching 55μΩ cm at p c . A huge residual resistivity is found to appear when the magnetic order disappears. (letter to the editor)

Population structure and genetic diversity of the parasite Trichomonas vaginalis in Bristol, UK.

Science.gov (United States)

Hawksworth, Joseph; Levy, Max; Smale, Chloe; Cheung, Dean; Whittle, Alice; Longhurst, Denise; Muir, Peter; Gibson, Wendy

2015-08-01

The protozoan parasite Trichomonas vaginalis is the causative agent of trichomoniasis, an extremely common, but non-life-threatening, sexually-transmitted disease throughout the world. Recent population genetics studies of T. vaginalis have detected high genetic diversity and revealed a two-type population structure, associated with phenotypic differences in sensitivity to metronidazole, the drug commonly used for treatment, and presence of T. vaginalis virus. There is currently a lack of data on UK isolates; most isolates examined to date are from the US. Here we used a recently described system for multilocus sequence typing (MLST) of T. vaginalis to study diversity of clinical isolates from Bristol, UK. We used MLST to characterise 23 clinical isolates of T. vaginalis collected from female patients during 2013. Seven housekeeping genes were PCR-amplified for each isolate and sequenced. The concatenated sequences were then compared with data from other MLST-characterised isolates available from http://tvaginalis.mlst.net/ to analyse the population structure and construct phylogenetic trees. Among the 23 isolates from the Bristol population of T. vaginalis, we found 23 polymorphic nucleotide sites, 25 different alleles and 19 sequence types (genotypes). Most isolates had a unique genotype, in agreement with the high levels of heterogeneity observed elsewhere in the world. A two-type population structure was evident from population genetic analysis and phylogenetic reconstruction split the isolates into two major clades. Tests for recombination in the Bristol population of T. vaginalis gave conflicting results, suggesting overall a clonal pattern of reproduction. We conclude that the Bristol population of T. vaginalis parasites conforms to the two-type population structure found in most other regions of the world. We found the MLST scheme to be an efficient genotyping method. The online MLST database provides a useful repository and resource that will prove

Biomechanical Diversity of Mating Structures among Harvestmen Species Is Consistent with a Spectrum of Precopulatory Strategies.

Directory of Open Access Journals (Sweden)

Mercedes Burns

Full Text Available Diversity in reproductive structures is frequently explained by selection acting at individual to generational timescales, but interspecific differences predicted by such models (e.g., female choice or sexual conflict are often untestable in a phylogenetic framework. An alternative approach focuses on clade- or function-specific hypotheses that predict evolutionary patterns in terms neutral to specific modes of sexual selection. Here we test a hypothesis that diversity of reproductive structures in leiobunine harvestmen (daddy longlegs of eastern North America reflects two sexually coevolved but non-overlapping precopulatory strategies, a primitive solicitous strategy (females enticed by penis-associated nuptial gifts, and a multiply derived antagonistic strategy (penis exerts mechanical force against armature of the female pregenital opening. Predictions of sexual coevolution and fidelity to precopulatory categories were tested using 10 continuously varying functional traits from 28 species. Multivariate analyses corroborated sexual coevolution but failed to partition species by precopulatory strategy, with multiple methods placing species along a spectrum of mechanical antagonistic potential. These findings suggest that precopulatory features within species reflect different co-occurring levels of solicitation and antagonism, and that gradualistic evolutionary pathways exist between extreme strategies. The ability to quantify antagonistic potential of precopulatory structures invites comparison with ecological variables that may promote evolutionary shifts in precopulatory strategies.

Proportioning whole-genome single-nucleotide-polymorphism diversity for the identification of geographic population structure and genetic ancestry

NARCIS (Netherlands)

O. Lao Grueso (Oscar); K. van Duijn (Kate); P. Kersbergen (Paula); P. de Knijff (Peter); M.H. Kayser (Manfred)

2006-01-01

textabstractThe identification of geographic population structure and genetic ancestry on the basis of a minimal set of genetic markers is desirable for a wide range of applications in medical and forensic sciences. However, the absence of sharp discontinuities in the neutral genetic diversity among

Bacterial diversity and community structure of supragingival plaques in adults with dental health or caries revealed by 16S pyrosequencing

Directory of Open Access Journals (Sweden)

Cuicui Xiao

2016-07-01

Full Text Available Dental caries has a polymicrobial etiology within the complex oral microbial ecosystem. However, the overall diversity and structure of supragingival plaque microbiota in adult dental health and caries are not well understood. Here, 160 supragingival plaque samples from patients with dental health and different severities of dental caries were collected for bacterial genomic DNA extraction, pyrosequencing by amplification of the 16S rDNA V1–V3 hypervariable regions, and bioinformatic analysis. High-quality sequences (2,261,700 clustered into 10,365 operational taxonomic units (OTUs; 97% identity, representing 453 independent species belonging to 122 genera, 66 families, 34 orders, 21 classes, and 12 phyla. All groups shared 7522 OTUs, indicating the presence of a core plaque microbiome. Smooth rarefaction curves were suggestive of plaque microbial diversity. α diversity analysis showed that healthy plaque microbial diversity exceeded that of dental caries, with the diversity decreasing gradually with the severity of caries. The dominant phyla of plaque microbiota included Bacteroidetes, Actinobacteria, Proteobacteria, Firmicutes, Fusobacteria, and TM7. The dominant genera included Capnocytophaga, Prevotella, Actinomyces, Corynebacterium, Neisseria, Streptococcus, Rothia, and Leptotrichia. β diversity analysis showed that the plaque microbial community structure was similar in all groups and that group members were relatively constant, only showing differences in abundance. Analysis of composition differences identified 10 health-related and 21 caries-related genera. Key genera (27 that potentially contributed to plaque microbiota distributions between groups were identified. Finally, co-occurrence network analysis and function prediction were performed. Treatment strategies directed toward modulating microbial interactions and their functional output should be further developed.

Population structure and diversity of citrus tristeza virus (CTV) isolates in Hunan province, China.

Science.gov (United States)

Xiao, Cui; Yao, Run-Xian; Li, Fang; Dai, Su-Ming; Licciardello, Grazia; Catara, Antonino; Gentile, Alessandra; Deng, Zi-Niu

2017-02-01

Stem-pitting (SP) is the main type of citrus tristeza virus (CTV) that causes severe damage to citrus trees, especially those of sweet orange, in Hunan province, China. Understanding the local CTV population structure should provide clues for effective mild strain cross-protection (MSCP) of the SP strain of CTV. In this study, markers for the p23 gene, multiple molecular markers (MMMs), and sequence analysis of the three silencing suppressor genes (p20, p23 and p25) were employed to analyze the genetic diversity and genotype composition of the CTV population based on 51 CTV-positive samples collected from 14 citrus orchards scattered around six major citrus-growing areas of Hunan. The results indicated that the CTV population structure was extremely complex and that infection was highly mixed. In total, p23 gene markers resulted in six profiles, and MMMs demonstrated 25 profiles. The severe VT and T3 types appeared to be predominantly associated with SP, while the mild T30 and RB types were related to asymptomatic samples. Based on phylogenetic analysis of the amino acid sequences of p20, p23 and p25, 19 representative CTV samples were classified into seven recently established CTV groups and a potentially novel one. A high level of genetic diversity, as well as potential recombination, was revealed among different CTV isolates. Five pure SP severe and two pure mild strains were identified by genotype composition analysis. Taken together, the results update the genetic diversity of CTV in Hunan with the detection of one possible novel strain, and this information might be applicable for the selection of appropriate mild CTV strains for controlling citrus SP disease through cross-protection.

Salinity shapes microbial diversity and community structure in surface sediments of the Qinghai-Tibetan Lakes.

Science.gov (United States)

Yang, Jian; Ma, Li'an; Jiang, Hongchen; Wu, Geng; Dong, Hailiang

2016-04-26

Investigating microbial response to environmental variables is of great importance for understanding of microbial acclimatization and evolution in natural environments. However, little is known about how microbial communities responded to environmental factors (e.g. salinity, geographic distance) in lake surface sediments of the Qinghai-Tibetan Plateau (QTP). In this study, microbial diversity and community structure in the surface sediments of nine lakes on the QTP were investigated by using the Illumina Miseq sequencing technique and the resulting microbial data were statistically analyzed in combination with environmental variables. The results showed total microbial community of the studied lakes was significantly correlated (r = 0.631, P diversity and community structure in the studied samples. In addition, the abundant and rare taxa (OTUs with relative abundance higher than 1% and lower than 0.01% within one sample, respectively) were significantly (P < 0.05) correlated (r = 0.427 and 0.783, respectively) with salinity, suggesting rare taxa might be more sensitive to salinity than their abundant counterparts, thus cautions should be taken in future when evaluating microbial response (abundant vs. rare sub-communities) to environmental conditions.

The Remarkable Structural Diversity Achieved in ent-Kaurane Diterpenes by Fungal Biotransformations

Directory of Open Access Journals (Sweden)

Jacqueline A. Takahashi

2014-02-01

Full Text Available The use of biotransformations in organic chemistry is widespread, with highlights of interesting applications in the functionalization of natural products containing unactivated carbons, like the kaurane diterpenes. A number of compounds with kaurane skeletons can be isolated in large amounts from several plant species and a myriad of biological activities has been related to these compounds. Studies on structure versus activity have showed that, in most cases, in kaurane diterpenes, activity increases with the increase of functionalization. Since naturally occurring kaurane diterpenes usually have limited functional groups to be used as targets for semi-synthetic modifications, production of more polar derivatives from kaurane diterpenes have been achieved mostly through the use of fungal biotransformations. In this review, selected examples the wonderful chemical diversity produced by fungi in kaurane diterpenes is presented. This diversity includes mainly hydroxylation of nearly all carbon atoms of the kaurane molecule, many of them carried out stereoselectively, as well as ring rearrangements, among other chemical modifications. Sources of starting materials, general biotransformation protocols employed, fungi with most consistent regioselectivity towards kaurane skeleton, as well as biological activities associated with starting materials and products are also described.

Acute abdomen in early pregnancy caused by torsion of bilateral huge multiloculated ovarian cysts

OpenAIRE

Sathiyakala Rajendran; Suthanthira Devi

2015-01-01

The association of pregnancy and torsion of bilateral huge benign ovarian cyst is rare. We report a case of multigravida at 13 weeks of pregnancy presenting with acute onset of lower abdominal pain. Ultrasound revealed bilateral multiloculated ovarian cysts of size 10x10 cm on right side and 15x10cm on left side with evidence of torsion and a single live intrauterine fetus of gestational age 13 weeks 4 days. Emergency laparotomy was done with vaginal susten 200 mg as perioperative tocolysis. ...

Genetic Diversity and Population Structure of Theileria annulata in Oman.

Science.gov (United States)

Al-Hamidhi, Salama; H Tageldin, Mohammed; Weir, William; Al-Fahdi, Amira; Johnson, Eugene H; Bobade, Patrick; Alqamashoui, Badar; Beja-Pereira, Albano; Thompson, Joanne; Kinnaird, Jane; Shiels, Brian; Tait, Andy; Babiker, Hamza

2015-01-01

Theileriosis, caused by a number of species within the genus Theileria, is a common disease of livestock in Oman. It is a major constraint to the development of the livestock industry due to a high rate of morbidity and mortality in both cattle and sheep. Since little is currently known about the genetic diversity of the parasites causing theileriosis in Oman, the present study was designed to address this issue with specific regard to T. annulata in cattle. Blood samples were collected from cattle from four geographically distinct regions in Oman for genetic analysis of the Theileria annulata population. Ten genetic markers (micro- and mini-satellites) representing all four chromosomes of T. annulata were applied to these samples using a combination of PCR amplification and fragment analysis. The resultant genetic data was analysed to provide a first insight into the structure of the T. annulata population in Oman. We applied ten micro- and mini-satellite markers to a total of 310 samples obtained from different regions (174 [56%] from Dhofar, 68 [22%] from Dhira, 44 [14.5%] from Batinah and 24 [8%] from Sharqia). A high degree of allelic diversity was observed among the four parasite populations. Expected heterozygosity for each site ranged from 0.816 to 0.854. A high multiplicity of infection was observed in individual hosts, with an average of 3.3 to 3.4 alleles per locus, in samples derived from Batinah, Dhofar and Sharqia regions. In samples from Dhira region, an average of 2.9 alleles per locus was observed. Mild but statistically significant linkage disequilibrium between pairs of markers was observed in populations from three of the four regions. In contrast, when the analysis was performed at farm level, no significant linkage disequilibrium was observed. Finally, no significant genetic differentiation was seen between the four populations, with most pair-wise FST values being less than 0.03. Slightly higher FST values (GST' = 0.075, θ = 0.07) were

Genetic Diversity and Population Structure of Theileria annulata in Oman.

Directory of Open Access Journals (Sweden)

Salama Al-Hamidhi

Full Text Available Theileriosis, caused by a number of species within the genus Theileria, is a common disease of livestock in Oman. It is a major constraint to the development of the livestock industry due to a high rate of morbidity and mortality in both cattle and sheep. Since little is currently known about the genetic diversity of the parasites causing theileriosis in Oman, the present study was designed to address this issue with specific regard to T. annulata in cattle.Blood samples were collected from cattle from four geographically distinct regions in Oman for genetic analysis of the Theileria annulata population. Ten genetic markers (micro- and mini-satellites representing all four chromosomes of T. annulata were applied to these samples using a combination of PCR amplification and fragment analysis. The resultant genetic data was analysed to provide a first insight into the structure of the T. annulata population in Oman.We applied ten micro- and mini-satellite markers to a total of 310 samples obtained from different regions (174 [56%] from Dhofar, 68 [22%] from Dhira, 44 [14.5%] from Batinah and 24 [8%] from Sharqia. A high degree of allelic diversity was observed among the four parasite populations. Expected heterozygosity for each site ranged from 0.816 to 0.854. A high multiplicity of infection was observed in individual hosts, with an average of 3.3 to 3.4 alleles per locus, in samples derived from Batinah, Dhofar and Sharqia regions. In samples from Dhira region, an average of 2.9 alleles per locus was observed. Mild but statistically significant linkage disequilibrium between pairs of markers was observed in populations from three of the four regions. In contrast, when the analysis was performed at farm level, no significant linkage disequilibrium was observed. Finally, no significant genetic differentiation was seen between the four populations, with most pair-wise FST values being less than 0.03. Slightly higher FST values (GST' = 0.075, �

Changes in diversity, abundance, and structure of soil bacterial communities in Brazilian Savanna under different land use systems.

Science.gov (United States)

Rampelotto, Pabulo Henrique; de Siqueira Ferreira, Adão; Barboza, Anthony Diego Muller; Roesch, Luiz Fernando Wurdig

2013-10-01

The Brazilian Savanna, also known as "Cerrado", is the richest and most diverse savanna in the world and has been ranked as one of the main hotspots of biodiversity. The Cerrado is a representative biome in Central Brazil and the second largest biome in species diversity of South America. Nevertheless, large areas of native vegetation have been converted to agricultural land including grain production, livestock, and forestry. In this view, understanding how land use affects microbial communities is fundamental for the sustainable management of agricultural ecosystems. The aim of this work was to analyze and compare the soil bacterial communities from the Brazilian Cerrado associated with different land use systems using high throughput pyrosequencing of 16S rRNA genes. Relevant differences were observed in the abundance and structure of bacterial communities in soils under different land use systems. On the other hand, the diversity of bacterial communities was not relevantly changed among the sites studied. Land use systems had also an important impact on specific bacterial groups in soil, which might change the soil function and the ecological processes. Acidobacteria, Proteobacteria, and Actinobacteria were the most abundant groups in the Brazilian Cerrado. These findings suggest that more important than analyzing the general diversity is to analyze the composition of the communities. Since soil type was the same among the sites, we might assume that land use was the main factor defining the abundance and structure of bacterial communities.

Genetic diversity and population structure of Chinese natural bermudagrass [Cynodon dactylon (L.) Pers.] germplasm based on SRAP markers.

Science.gov (United States)

Zheng, Yiqi; Xu, Shaojun; Liu, Jing; Zhao, Yan; Liu, Jianxiu

2017-01-01

Bermudagrass [Cynodon dactylon (L.) Pers.], an important turfgrass used in public parks, home lawns, golf courses and sports fields, is widely distributed in China. In the present study, sequence-related amplified polymorphism (SRAP) markers were used to assess genetic diversity and population structure among 157 indigenous bermudagrass genotypes from 20 provinces in China. The application of 26 SRAP primer pairs produced 340 bands, of which 328 (96.58%) were polymorphic. The polymorphic information content (PIC) ranged from 0.36 to 0.49 with a mean of 0.44. Genetic distance coefficients among accessions ranged from 0.04 to 0.61, with an average of 0.32. The results of STRUCTURE analysis suggested that 157 bermudagrass accessions can be grouped into three subpopulations. Moreover, according to clustering based on the unweighted pair-group method of arithmetic averages (UPGMA), accessions were divided into three major clusters. The UPGMA dendrogram revealed that accessions from identical or adjacent areas were generally, but not entirely, clustered into the same cluster. Comparison of the UPGMA dendrogram and the Bayesian STRUCTURE analysis showed general agreement between the population subdivisions and the genetic relationships among accessions. Principal coordinate analysis (PCoA) with SRAP markers revealed a similar grouping of accessions to the UPGMA dendrogram and STRUCTUE analysis. Analysis of molecular variance (AMOVA) indicated that 18% of total molecular variance was attributed to diversity among subpopulations, while 82% of variance was associated with differences within subpopulations. Our study represents the most comprehensive investigation of the genetic diversity and population structure of bermudagrass in China to date, and provides valuable information for the germplasm collection, genetic improvement, and systematic utilization of bermudagrass.

MBGD update 2013: the microbial genome database for exploring the diversity of microbial world.

Science.gov (United States)

Uchiyama, Ikuo; Mihara, Motohiro; Nishide, Hiroyo; Chiba, Hirokazu

2013-01-01

The microbial genome database for comparative analysis (MBGD, available at http://mbgd.genome.ad.jp/) is a platform for microbial genome comparison based on orthology analysis. As its unique feature, MBGD allows users to conduct orthology analysis among any specified set of organisms; this flexibility allows MBGD to adapt to a variety of microbial genomic study. Reflecting the huge diversity of microbial world, the number of microbial genome projects now becomes several thousands. To efficiently explore the diversity of the entire microbial genomic data, MBGD now provides summary pages for pre-calculated ortholog tables among various taxonomic groups. For some closely related taxa, MBGD also provides the conserved synteny information (core genome alignment) pre-calculated using the CoreAligner program. In addition, efficient incremental updating procedure can create extended ortholog table by adding additional genomes to the default ortholog table generated from the representative set of genomes. Combining with the functionalities of the dynamic orthology calculation of any specified set of organisms, MBGD is an efficient and flexible tool for exploring the microbial genome diversity.

Design and synthesis of diverse functional kinked nanowire structures for nanoelectronic bioprobes.

Science.gov (United States)

Xu, Lin; Jiang, Zhe; Qing, Quan; Mai, Liqiang; Zhang, Qingjie; Lieber, Charles M

2013-02-13

Functional kinked nanowires (KNWs) represent a new class of nanowire building blocks, in which functional devices, for example, nanoscale field-effect transistors (nanoFETs), are encoded in geometrically controlled nanowire superstructures during synthesis. The bottom-up control of both structure and function of KNWs enables construction of spatially isolated point-like nanoelectronic probes that are especially useful for monitoring biological systems where finely tuned feature size and structure are highly desired. Here we present three new types of functional KNWs including (1) the zero-degree KNW structures with two parallel heavily doped arms of U-shaped structures with a nanoFET at the tip of the "U", (2) series multiplexed functional KNW integrating multi-nanoFETs along the arm and at the tips of V-shaped structures, and (3) parallel multiplexed KNWs integrating nanoFETs at the two tips of W-shaped structures. First, U-shaped KNWs were synthesized with separations as small as 650 nm between the parallel arms and used to fabricate three-dimensional nanoFET probes at least 3 times smaller than previous V-shaped designs. In addition, multiple nanoFETs were encoded during synthesis in one of the arms/tip of V-shaped and distinct arms/tips of W-shaped KNWs. These new multiplexed KNW structures were structurally verified by optical and electron microscopy of dopant-selective etched samples and electrically characterized using scanning gate microscopy and transport measurements. The facile design and bottom-up synthesis of these diverse functional KNWs provides a growing toolbox of building blocks for fabricating highly compact and multiplexed three-dimensional nanoprobes for applications in life sciences, including intracellular and deep tissue/cell recordings.

A comprehensive analysis of the Omp85/TpsB protein superfamily structural diversity, taxonomic occurrence, and evolution

Science.gov (United States)

Heinz, Eva; Lithgow, Trevor

2014-01-01

Members of the Omp85/TpsB protein superfamily are ubiquitously distributed in Gram-negative bacteria, and function in protein translocation (e.g., FhaC) or the assembly of outer membrane proteins (e.g., BamA). Several recent findings are suggestive of a further level of variation in the superfamily, including the identification of the novel membrane protein assembly factor TamA and protein translocase PlpD. To investigate the diversity and the causal evolutionary events, we undertook a comprehensive comparative sequence analysis of the Omp85/TpsB proteins. A total of 10 protein subfamilies were apparent, distinguished in their domain structure and sequence signatures. In addition to the proteins FhaC, BamA, and TamA, for which structural and functional information is available, are families of proteins with so far undescribed domain architectures linked to the Omp85 β-barrel domain. This study brings a classification structure to a dynamic protein superfamily of high interest given its essential function for Gram-negative bacteria as well as its diverse domain architecture, and we discuss several scenarios of putative functions of these so far undescribed proteins. PMID:25101071

Expanded therapeutic potential in activity space of next-generation 5-nitroimidazole antimicrobials with broad structural diversity

Science.gov (United States)

Miyamoto, Yukiko; Kalisiak, Jarosław; Korthals, Keith; Lauwaet, Tineke; Cheung, Dae Young; Lozano, Ricardo; Cobo, Eduardo R.; Upcroft, Peter; Upcroft, Jacqueline A.; Berg, Douglas E.; Gillin, Frances D.; Fokin, Valery V.; Sharpless, K. Barry; Eckmann, Lars

2013-01-01

Metronidazole and other 5-nitroimidazoles (5-NI) are among the most effective antimicrobials available against many important anaerobic pathogens, but evolving resistance is threatening their long-term clinical utility. The common 5-NIs were developed decades ago, yet little 5-NI drug development has since taken place, leaving the true potential of this important drug class unexplored. Here we report on a unique approach to the modular synthesis of diversified 5-NIs for broad exploration of their antimicrobial potential. Many of the more than 650 synthesized compounds, carrying structurally diverse functional groups, have vastly improved activity against a range of microbes, including the pathogenic protozoa Giardia lamblia and Trichomonas vaginalis, and the bacterial pathogens Helicobacter pylori, Clostridium difficile, and Bacteroides fragilis. Furthermore, they can overcome different forms of drug resistance, and are active and nontoxic in animal infection models. These findings provide impetus to the development of structurally diverse, next-generation 5-NI drugs as agents in the antimicrobial armamentarium, thus ensuring their future viability as primary therapeutic agents against many clinically important infections. PMID:24101497

Ciliate diversity, community structure, and novel taxa in lakes of the McMurdo Dry Valleys, Antarctica.

Science.gov (United States)

Xu, Yuan; Vick-Majors, Trista; Morgan-Kiss, Rachael; Priscu, John C; Amaral-Zettler, Linda

2014-10-01

We report an in-depth survey of next-generation DNA sequencing of ciliate diversity and community structure in two permanently ice-covered McMurdo Dry Valley lakes during the austral summer and autumn (November 2007 and March 2008). We tested hypotheses on the relationship between species richness and environmental conditions including environmental extremes, nutrient status, and day length. On the basis of the unique environment that exists in these high-latitude lakes, we expected that novel taxa would be present. Alpha diversity analyses showed that extreme conditions-that is, high salinity, low oxygen, and extreme changes in day length-did not impact ciliate richness; however, ciliate richness was 30% higher in samples with higher dissolved organic matter. Beta diversity analyses revealed that ciliate communities clustered by dissolved oxygen, depth, and salinity, but not by season (i.e., day length). The permutational analysis of variance test indicated that depth, dissolved oxygen, and salinity had significant influences on the ciliate community for the abundance matrices of resampled data, while lake and season were not significant. This result suggests that the vertical trends in dissolved oxygen concentration and salinity may play a critical role in structuring ciliate communities. A PCR-based strategy capitalizing on divergent eukaryotic V9 hypervariable region ribosomal RNA gene targets unveiled two new genera in these lakes. A novel taxon belonging to an unknown class most closely related to Cryptocaryon irritans was also inferred from separate gene phylogenies. © 2014 Marine Biological Laboratory.

Genetic diversity and population structure of elite foxtail millet [Setaria italica (L.) P. Beauv.] germplasm in China

Science.gov (United States)

China is among the countries that have the most severe water deficiency. Due to its excellent drought tolerance, foxtail millet [Setaria italica (L.) P. Beauv.] has become one of the important cereal crops in China. Information on genetic diversity and population structure of foxtail millet may faci...

Structural diversity: a multi-dimensional approach to assess recreational services in urban parks.

Science.gov (United States)

Voigt, Annette; Kabisch, Nadja; Wurster, Daniel; Haase, Dagmar; Breuste, Jürgen

2014-05-01

Urban green spaces provide important recreational services for urban residents. In general, when park visitors enjoy "the green," they are in actuality appreciating a mix of biotic, abiotic, and man-made park infrastructure elements and qualities. We argue that these three dimensions of structural diversity have an influence on how people use and value urban parks. We present a straightforward approach for assessing urban parks that combines multi-dimensional landscape mapping and questionnaire surveys. We discuss the method as well the results from its application to differently sized parks in Berlin and Salzburg.

Population genetic diversity and structure analysis of wild apricot (Prunus armeniaca L.) revealed by ssr markers in the Tien-Shan mountains of China

International Nuclear Information System (INIS)

Hu, X.; Ni, B.; Zheng, P.; Li, M.

2018-01-01

The simple sequence repeat markers were used to investigate the population genetic diversity and structure of 212 germplasm samples from 14 apricot (Prunus armeniaca) populations in the western of Tien-Shan Mountains, Sinkiang, China. The relatively high expected heterozygosity and Shannon's diversity index indicated the apricot populations maintained a high level of genetic diversity (He = 0.6109, I = 1.2208), with the population in Tuergen ditch of Xinyuan County having the highest genetic diversity index. A high level of intra-population genetic differentiation (91.51%) and a lower level of inter-population genetic differentiation were occurred, as well as a moderate but steady inter-population gene flow (Nm = 2.3735). The self-incompatible pattern, wide distribution, and long-distance pollen transmission via insects and gale are the main factors underlying the genetic variation structure. The UPGMA cluster analysis and genetic structure analysis showed that apricot germplasm could be divided into two or four groups, which was basically consistent with the geographic distribution pattern. The inter-population genetic distance and geographic distance showed a significant correlation (r = 0.2658, p<0.05). (author)

Syndecans as cell surface receptors: Unique structure equates with functional diversity

DEFF Research Database (Denmark)

Choi, Youngsil; Chung, Heesung; Jung, Heyjung

2011-01-01

An increasing number of functions for syndecan cell surface heparan sulfate proteoglycans have been proposed over the last decade. Moreover, aberrant syndecan regulation has been found to play a critical role in multiple pathologies, including cancers, as well as wound healing and inflammation....... As receptors, they have much in common with other molecules on the cell surface. Syndecans are type I transmembrane molecules with cytoplasmic domains that link to the actin cytoskeleton and can interact with a number of regulators. However, they are also highly complex by virtue of their external...... glycosaminoglycan chains, especially heparan sulfate. This heterodisperse polysaccharide has the potential to interact with many ligands from diverse protein families. Here, we relate the structural features of syndecans to some of their known functions....

Structural and Functional Diversity of Weed Species in Organic and Conventional Rice Agro-Ecosystems

Directory of Open Access Journals (Sweden)

S. Y. Mousawi Toghani

2016-02-01

Full Text Available Introduction Diversity reflects the complexity of a system and can maintain its sustainability. Higherdiversity, results in higher inherent complexity of agro-ecosystems and strengthen their processes. It is necessary to realize the spatial distribution and temporal properties of the biodiversity components in agro-ecosystems, for the conservation and optimal utilization. Since weeds as a complementary component of agro-ecosystems and are inseparable, so the study of species, their functional and structural diversity of them can play an important role in weed management and balance in ecological systems. Materials and Methods This study was performed to determine the effects of different management systems on structural, and functional diversity of paddy weeds in Mazandaran province. Three rice fields, ranged from 0.3 to 0.5 ha, were chosen for each management system. Samples were collected from three fields running under each selected management system (organic and conventional. Data (number of weed species and their density were randomly gathered from 9 quadrates (1m×1m per each field in four stages (tillering, stem elongation, grain filling and after harvest. The diversity, evenness, frequency and similarity indices for weeds were determined at genera and species level. Data analysis carried out through T-test and grouping performed via cluster analysis as hierarchy. Results and Discussion All monitored weeds can be classified into four plant family including cereals (Poaceae, sedges (Cyperaceae, plantain (Plantaginaceae and chicory (Asteraceae.Under conventional systems the values of weed diversity indices were higher during tillering and stem elongation compared with organic ones, and were lower during grain filling and after harvest stages. However indices of weed evenness showed contrary tendency. Both Sympson and Shanon-Wiener diversity indices, consist of two clusters in 76% similarity. Evenness indices of Kamargo and Smith

Isotopic diversity indices: how sensitive to food web structure?

Science.gov (United States)

Brind'Amour, Anik; Dubois, Stanislas F

2013-01-01

Recently revisited, the concept of niche ecology has lead to the formalisation of functional and trophic niches using stable isotope ratios. Isotopic diversity indices (IDI) derived from a set of measures assessing the dispersion/distribution of points in the δ-space were recently suggested and increasingly used in the literature. However, three main critics emerge from the use of these IDI: 1) they fail to account for the isotopic sources overlap, 2) some indices are highly sensitive to the number of species and/or the presence of rare species, and 3) the lack of standardization prevents any spatial and temporal comparisons. Using simulations we investigated the ability of six commonly used IDI to discriminate among different trophic food web structures, with a focus on the first two critics. We tested the sensitivity of the IDI to five food web structures along a gradient of sources overlap, varying from two distinct food chains with differentiated sources to two superimposed food chains sharing two sources. For each of the food web structure we varied the number of species (from 10 to 100 species) and the type of species feeding behaviour (i.e. random or selective feeding). Values of IDI were generally larger in food webs with distinct basal sources and tended to decrease as the superimposition of the food chains increased. This was more pronounced when species displayed food preferences in comparison to food webs where species fed randomly on any prey. The number of species composing the food web also had strong effects on the metrics, including those that were supposedly less sensitive to small sample size. In all cases, computing IDI on food webs with low numbers of species always increases the uncertainty of the metrics. A threshold of ~20 species was detected above which several metrics can be safely used.

Jatropha curcas L. Root Structure and Growth in Diverse Soils

Science.gov (United States)

Valdés-Rodríguez, Ofelia Andrea; Sánchez-Sánchez, Odilón; Pérez-Vázquez, Arturo; Caplan, Joshua S.; Danjon, Frédéric

2013-01-01

Unlike most biofuel species, Jatropha curcas has promise for use in marginal lands, but it may serve an additional role by stabilizing soils. We evaluated the growth and structural responsiveness of young J. curcas plants to diverse soil conditions. Soils included a sand, a sandy-loam, and a clay-loam from eastern Mexico. Growth and structural parameters were analyzed for shoots and roots, although the focus was the plasticity of the primary root system architecture (the taproot and four lateral roots). The sandy soil reduced the growth of both shoot and root systems significantly more than sandy-loam or clay-loam soils; there was particularly high plasticity in root and shoot thickness, as well as shoot length. However, the architecture of the primary root system did not vary with soil type; the departure of the primary root system from an index of perfect symmetry was 14 ± 5% (mean ± standard deviation). Although J. curcas developed more extensively in the sandy-loam and clay-loam soils than in sandy soil, it maintained a consistent root to shoot ratio and root system architecture across all types of soil. This strong genetic determination would make the species useful for soil stabilization purposes, even while being cultivated primarily for seed oil. PMID:23844412

Jatropha curcas L. root structure and growth in diverse soils.

Science.gov (United States)

Valdés-Rodríguez, Ofelia Andrea; Sánchez-Sánchez, Odilón; Pérez-Vázquez, Arturo; Caplan, Joshua S; Danjon, Frédéric

2013-01-01

Unlike most biofuel species, Jatropha curcas has promise for use in marginal lands, but it may serve an additional role by stabilizing soils. We evaluated the growth and structural responsiveness of young J. curcas plants to diverse soil conditions. Soils included a sand, a sandy-loam, and a clay-loam from eastern Mexico. Growth and structural parameters were analyzed for shoots and roots, although the focus was the plasticity of the primary root system architecture (the taproot and four lateral roots). The sandy soil reduced the growth of both shoot and root systems significantly more than sandy-loam or clay-loam soils; there was particularly high plasticity in root and shoot thickness, as well as shoot length. However, the architecture of the primary root system did not vary with soil type; the departure of the primary root system from an index of perfect symmetry was 14 ± 5% (mean ± standard deviation). Although J. curcas developed more extensively in the sandy-loam and clay-loam soils than in sandy soil, it maintained a consistent root to shoot ratio and root system architecture across all types of soil. This strong genetic determination would make the species useful for soil stabilization purposes, even while being cultivated primarily for seed oil.

Jatropha curcas L. Root Structure and Growth in Diverse Soils

Directory of Open Access Journals (Sweden)

Ofelia Andrea Valdés-Rodríguez

2013-01-01

Full Text Available Unlike most biofuel species, Jatropha curcas has promise for use in marginal lands, but it may serve an additional role by stabilizing soils. We evaluated the growth and structural responsiveness of young J. curcas plants to diverse soil conditions. Soils included a sand, a sandy-loam, and a clay-loam from eastern Mexico. Growth and structural parameters were analyzed for shoots and roots, although the focus was the plasticity of the primary root system architecture (the taproot and four lateral roots. The sandy soil reduced the growth of both shoot and root systems significantly more than sandy-loam or clay-loam soils; there was particularly high plasticity in root and shoot thickness, as well as shoot length. However, the architecture of the primary root system did not vary with soil type; the departure of the primary root system from an index of perfect symmetry was 14±5% (mean ± standard deviation. Although J. curcas developed more extensively in the sandy-loam and clay-loam soils than in sandy soil, it maintained a consistent root to shoot ratio and root system architecture across all types of soil. This strong genetic determination would make the species useful for soil stabilization purposes, even while being cultivated primarily for seed oil.

Putting Diversity to Work

DEFF Research Database (Denmark)

Holck, Lotte

2016-01-01

Purpose: The purpose of this article is to critically explore why a diversity agenda in favor of equal opportunities failed despite apparent organizational support and commitment to diversity. Design/methodology/approach: Drawing on data from a municipal center, this study inquires into how...... organizational dynamics of power and hierarchy influence change efforts to alter practices of inequality. The study is positioned within critical diversity research and structured around an analysis of the researcher’s fieldwork experiences. Findings: The analysis examines into why change efforts failed despite...... organizational approval of a diversity agenda, open-mindedness towards change and legitimacy in regard to diversity. Paradoxically, change efforts designed to alter the status quo were, in practice, derailed and circumvented through power dynamics reproducing organizational inequality. Research limitations...

Diversity of Pyrrolizidine Alkaloids in the Boraginaceae Structures, Distribution, and Biological Properties

Directory of Open Access Journals (Sweden)

Assem El-Shazly

2014-04-01

Full Text Available Among the diversity of secondary metabolites which are produced by plants as means of defence against herbivores and microbes, pyrrolizidine alkaloids (PAs are common in Boraginaceae, Asteraceae and some other plant families. Pyrrolizidine alkaloids are infamous as toxic compounds which can alkylate DNA und thus cause mutations and even cancer in herbivores and humans. Almost all genera of the family Boraginaceae synthesize and store this type of alkaloids. This review reports the available information on the present status (literature up to early 2014 of the pyrrolizidine alkaloids in the Boraginaceae and summarizes the topics structure, distribution, chemistry, chemotaxonomic significance, and biological properties.

Assessment of Genetic Diversity and Structure of Large Garlic (Allium sativum Germplasm Bank, by Diversity Arrays Technology “Genotyping-by-Sequencing” Platform (DArTseq

Directory of Open Access Journals (Sweden)

Leticia A. Egea

2017-07-01

Full Text Available Garlic (Allium sativum is used worldwide in cooking and industry, including pharmacology/medicine and cosmetics, for its interesting properties. Identifying redundancies in germplasm blanks to generate core collections is a major concern, mostly in large stocks, in order to reduce space and maintenance costs. Yet, similar appearance and phenotypic plasticity of garlic varieties hinder their morphological classification. Molecular studies are challenging, due to the large and expected complex genome of this species, with asexual reproduction. Classical molecular markers, like isozymes, RAPD, SSR, or AFLP, are not convenient to generate germplasm core-collections for this species. The recent emergence of high-throughput genotyping-by-sequencing (GBS approaches, like DArTseq, allow to overcome such limitations to characterize and protect genetic diversity. Therefore, such technology was used in this work to: (i assess genetic diversity and structure of a large garlic-germplasm bank (417 accessions; (ii create a core collection; (iii relate genotype to agronomical features; and (iv describe a cost-effective method to manage genetic diversity in garlic-germplasm banks. Hierarchical-cluster analysis, principal-coordinates analysis and STRUCTURE showed general consistency, generating three main garlic-groups, mostly determined by variety and geographical origin. In addition, high-resolution genotyping identified 286 unique and 131 redundant accessions, used to select a reduced size germplasm-bank core collection. This demonstrates that DArTseq is a cost-effective method to analyze species with large and expected complex genomes, like garlic. To the best of our knowledge, this is the first report of high-throughput genotyping of a large garlic germplasm. This is particularly interesting for garlic adaptation and improvement, to fight biotic and abiotic stresses, in the current context of climate change and global warming.

Explaining the Linguistic Diversity of Sahul Using Population Models

Science.gov (United States)

Reesink, Ger; Singer, Ruth; Dunn, Michael

2009-01-01

The region of the ancient Sahul continent (present day Australia and New Guinea, and surrounding islands) is home to extreme linguistic diversity. Even apart from the huge Austronesian language family, which spread into the area after the breakup of the Sahul continent in the Holocene, there are hundreds of languages from many apparently unrelated families. On each of the subcontinents, the generally accepted classification recognizes one large, widespread family and a number of unrelatable smaller families. If these language families are related to each other, it is at a depth which is inaccessible to standard linguistic methods. We have inferred the history of structural characteristics of these languages under an admixture model, using a Bayesian algorithm originally developed to discover populations on the basis of recombining genetic markers. This analysis identifies 10 ancestral language populations, some of which can be identified with clearly defined phylogenetic groups. The results also show traces of early dispersals, including hints at ancient connections between Australian languages and some Papuan groups (long hypothesized, never before demonstrated). Systematic language contact effects between members of big phylogenetic groups are also detected, which can in some cases be identified with a diffusional or substrate signal. Most interestingly, however, there remains striking evidence of a phylogenetic signal, with many languages showing negligible amounts of admixture. PMID:19918360

The influence of vegetation structure on spider species richness, diversity and community organization in the Apšuciems calcareous fen, Latvia

Directory of Open Access Journals (Sweden)

Štokmane, M.

2016-07-01

Full Text Available Calcareous fens are considered to be among the most threatened ecosystems of Europe. They are also one of the most diverse habitats as they support an incredibly rich and diverse range of plant and animal species. However, in spite of their diversity, calcareous fens are still poorly investigated, especially when referring to fen invertebrates, such as spiders. Because spiders are good bioindicators, knowledge of their ecology in rare and threatened habitats is of interest. The aim of this study was to document the composition and diversity of spider species, families and foraging guilds in the ground– and grass–layers of the Apšuciems calcareous fen, and to evaluate the influence of vegetation structure on spider community organization. In summer 2012, we collected ground–dwelling spiders using pitfall traps and grass–dwelling spiders using sweep–netting. A total of 2,937 spider individuals belonging to 19 families and 80 species was collected in the Apšuciems fen. Our results indicate that spider species and families tend to be stratified across the vertical structure of the habitat; the spider composition in the ground stratum differed from that in the grass stratum. On the contrary, however, the spider foraging guild structure between the ground–layer and the grass–layer was similar. Each of the two studied strata presented similar guilds in similar proportions. Our results also showed that spider composition differed considerably between fen parts and that much of this variability could be explained by the architectural properties of the habitat. More diverse vegetation generally supported a higher number of spider species.

Cryptic Coral Reef Diversity Across the Pacific Assessed using Autonomous Reef Monitoring Structures and Multi-omic Methods

Science.gov (United States)

Ransome, E. J.; Timmers, M.; Hartmann, A.; Collins, A.; Meyer, C.

2016-02-01

Coral reefs harbor diverse and distinct eukaryotic, bacterial and viral communities, which are critically important for their success. The lack of standardized measures for comprehensively assessing reef diversity has been a major obstacle in understanding the complexity of eukaryotic and microbial associations, and the processes that drive ecosystem shifts on reefs. ARMS, which mimic the structural complexity of the reef using artificial settlement plates, were used to systematically measure reef biodiversity across the Indo-Pacific. This device allows for standardized sampling of reef microbes to metazoans, providing the opportunity to investigate the fundamental links between these groups at an ecosystem level. We integrate the use of traditional ecology methods with metagenomics and metabolomics (metabolic predictors) to quantify the taxonomic composition of one of the planet's most diverse ecosystems and to assess the fundamental links between these cryptic communities and ecosystem function along geographical and anthropogenic stress gradients.

Distribution of Escherichia coli in a coastal lagoon (Venice, Italy): Temporal patterns, genetic diversity and the role of tidal forcing.

Science.gov (United States)

Perini, L; Quero, G M; García, E Serrano; Luna, G M

2015-12-15

Despite its worldwide importance as fecal indicator in aquatic systems, little is known about the diversity of Escherichia coli in the environment and the factors driving its spatial distribution. The city of Venice (Italy), lying at the forefront of a large European lagoon, is an ideal site to study the mechanisms driving the fate of fecal bacteria, due to the huge fluxes of tourists, the city's unique architecture (causing poor efficiency of sewages treatment), and the long branching network of canals crossing the city. We summarize the results of a multi-year investigation to study the temporal dynamics of E. coli around the city, describe the population structure (by assigning isolates to their phylogenetic group) and the genotypic diversity, and explore the role of environmental factors in determining its variability. E. coli abundance in water was highly variable, ranging from being undetectable up to 10(4) Colony Forming Units (CFU) per 100 ml. Abundance did not display significant relationships with the water physico-chemical variables. The analysis of the population structure showed the presence of all known phylogroups, including extra-intestinal and potentially pathogenic ones. The genotypic diversity was very high, as likely consequence of the heterogeneous input of fecal bacteria from the city, and showed site-specific patterns. Intensive sampling during the tidal fluctuations highlighted the prominent role of tides, rather than environmental variables, as source of spatial variation, with a more evident influence in water than sediments. These results, the first providing information on the genetic properties, spatial heterogeneity and influence of tides on E. coli populations around Venice, have implications to manage the fecal pollution, and the associated waterborne disease risks, in coastal cities lying in front of lagoons and semi-enclosed basins. Copyright © 2015 Elsevier Ltd. All rights reserved.

Vegetation types, dominant compositions, woody plant diversity and stand structure in Trishna Wildlife Sanctuary of Northeast India.

Science.gov (United States)

Majumdar, Koushik; Datta, B K

2015-03-01

Present study was carried out to assess the vegetation types, diversity and phytosociological status of woody plants in Trishna Wildlife Sanctuary of Tripura, Northeast India. Vegetation data was derived by 25 line transects (10 m wide and 500 m length, each 0.5 ha size). All woody species at >10 cm gbh (Girth at Breast Height) within each plots were measured and counted. A total of six forest types were classified by cluster analysis using Importance Value Index (IVI) of 289 woody species. Species diversity, forest structure and woody community associations were evaluated and discussed. One way ANOVA revealed significant differences in all species diversity measures and stand structure along the forest types. Distribution of stem density at ten different gbh classes showed reverse J-shaped curves. Population status of woody plants was also examined through grouping of all individuals into four population age stages viz. sapling ( or = 30 - 120 - 210 cm gbh) and old (> or =210 cm). To observe dominant composition and species population trend, IVI of top ten dominant species from all forest types were tabulated. The present study suggested that Trishna Wildlife Sanctuary is an important habitat in Tripura from floristic point of view and it should be conserved on priority basis for remaining wildlife endurances and monitor for forest livelihoods products for sustainable biodiversity conservation in this region.

Insights into the genetic structure and diversity of 38 South Asian Indians from deep whole-genome sequencing.

Directory of Open Access Journals (Sweden)

Lai-Ping Wong

2014-05-01

Full Text Available South Asia possesses a significant amount of genetic diversity due to considerable intergroup differences in culture and language. There have been numerous reports on the genetic structure of Asian Indians, although these have mostly relied on genotyping microarrays or targeted sequencing of the mitochondria and Y chromosomes. Asian Indians in Singapore are primarily descendants of immigrants from Dravidian-language-speaking states in south India, and 38 individuals from the general population underwent deep whole-genome sequencing with a target coverage of 30X as part of the Singapore Sequencing Indian Project (SSIP. The genetic structure and diversity of these samples were compared against samples from the Singapore Sequencing Malay Project and populations in Phase 1 of the 1,000 Genomes Project (1 KGP. SSIP samples exhibited greater intra-population genetic diversity and possessed higher heterozygous-to-homozygous genotype ratio than other Asian populations. When compared against a panel of well-defined Asian Indians, the genetic makeup of the SSIP samples was closely related to South Indians. However, even though the SSIP samples clustered distinctly from the Europeans in the global population structure analysis with autosomal SNPs, eight samples were assigned to mitochondrial haplogroups that were predominantly present in Europeans and possessed higher European admixture than the remaining samples. An analysis of the relative relatedness between SSIP with two archaic hominins (Denisovan, Neanderthal identified higher ancient admixture in East Asian populations than in SSIP. The data resource for these samples is publicly available and is expected to serve as a valuable complement to the South Asian samples in Phase 3 of 1 KGP.

Hypointensity on postcontrast MR imaging from compression of the sacral promontory in enlarged uterus with huge leiomyoma and adenomyosis

International Nuclear Information System (INIS)

Uotani, Kensuke; Monzawa, Shuichi; Adachi, Shuji; Takemori, Masayuki; Kaji, Yasushi; Sugimura, Kazuro

2007-01-01

In patients with huge leiomyoma and with adenomyosis of the uterus, a peculiar area of hypointensity was occasionally observed on postcontrast magnetic resonance (MR) imaging in the dorsal portion of the enlarged uterus near the sacral promontory. We describe the imaging characteristics of these MR findings and correlate them with histopathological findings to examine whether the areas represent specific pathological changes. Ten patients with huge leiomyomas and two with huge adenomyotic lesions whose imaging revealed the hypointensity were enrolled. All had enlarged uteri that extended beyond the sacral promontory. MR findings of the hypointense areas were evaluated and correlated with histopathological findings in 5 patients with leiomyoma and two with adenomyosis who had hysterectomy. The ten patients with leiomyoma showed flare-shaped hypointensity arising from the dorsal surface of the uterine body that extended deep into the tumor. The base of the hypointense areas was narrow in 5 patients with intramural leiomyoma and broad in five with subserosal leiomyoma. Two patients with adenomyosis showed nodular-shaped areas of hypointensity in front of the sacral promontory. Precontrast T 1 - and T 2 -weighted MR images showed no signal abnormalities in the portions corresponding to the hypointensity in any of the 12 patients. Pathological examinations showed no specific findings in the portions corresponding to the hypointensity in the 7 patients who had hysterectomy. The areas of hypointensity may represent functional changes, such as decreased localized blood flow caused by compression of the sacral promontory. (author)

Population Structure of Pseudocercospora fijiensis in Costa Rica Reveals Shared Haplotype Diversity with Southeast Asian Populations.

Science.gov (United States)

Saville, Amanda; Charles, Melodi; Chavan, Suchitra; Muñoz, Miguel; Gómez-Alpizar, Luis; Ristaino, Jean Beagle

2017-12-01

Pseudocercospora fijiensis is the causal pathogen of black Sigatoka, a devastating disease of banana that can cause 20 to 80% yield loss in the absence of fungicides in banana crops. The genetic structure of populations of P. fijiensis in Costa Rica was examined and compared with Honduran and global populations to better understand migration patterns and inform management strategies. In total, 118 isolates of P. fijiensis collected from Costa Rica and Honduras from 2010 to 2014 were analyzed using multilocus genotyping of six loci and compared with a previously published global dataset of populations of P. fijiensis. The Costa Rican and Honduran populations shared haplotype diversity with haplotypes from Southeast Asia, Oceania, and the Americas but not Africa for all but one of the six loci studied. Gene flow and shared haplotype diversity was found in Honduran and Costa Rican populations of the pathogen. The data indicate that the haplotypic diversity observed in Costa Rican populations of P. fijiensis is derived from dispersal from initial outbreak sources in Honduras and admixtures between genetically differentiated sources from Southeast Asia, Oceania, and the Americas.

Development of novel SSR markers for evaluation of genetic diversity and population structure in Tribulus terrestris L. (Zygophyllaceae).

Science.gov (United States)

Kaur, Kuljit; Sharma, Vikas; Singh, Vijay; Wani, Mohammad Saleem; Gupta, Raghbir Chand

2016-12-01

Tribulus terrestris L., commonly called puncture vine and gokhru, is an important member of Zygophyllaceae. The species is highly important in context to therapeutic uses and provides important active principles responsible for treatment of various diseases and also used as tonic. It is widely distributed in tropical regions of India and the world. However, status of its genetic diversity remained concealed due to lack of research work in this species. In present study, genetic diversity and structure of different populations of T. terrestris from north India was examined at molecular level using newly developed Simple Sequence Repeat (SSR) markers. In total, 20 primers produced 48 alleles in a size range of 100-500 bp with maximum (4) fragments amplified by TTMS-1, TTMS-25 and TTMS-33. Mean Polymorphism Information Content (PIC) and Marker Index (MI) were 0.368 and 1.01, respectively. Dendrogram showed three groups, one of which was purely containing accessions from Rajasthan while other two groups corresponded to Punjab and Haryana regions with intermixing of few other accessions. Analysis of molecular variance partitioned 76 % genetic variance within populations and 24 % among populations. Bayesian model based STRUCTURE analysis detected two genetic stocks for analyzed germplasm and also detected some admixed individuals. Different geographical populations of this species showed high level of genetic diversity. Results of present study can be useful in identifying diverse accessions and management of this plant resource. Moreover, the novel SSR markers developed can be utilized for various genetic analyses in this species in future.

Subcortical heterotopia appearing as huge midline mass in the newborn brain.

Science.gov (United States)

Fukumura, Shinobu; Watanabe, Toshihide; Kimura, Sachiko; Ochi, Satoko; Yoshifuji, Kazuhisa; Tsutsumi, Hiroyuki

2016-02-01

We report the case of a 2-year-old boy who showed a huge midline mass in the brain at prenatal assessment. After birth, magnetic resonance imaging (MRI) revealed a conglomerate mass with an infolded microgyrus at the midline, which was suspected as a midline brain-in-brain malformation. MRI also showed incomplete cleavage of his frontal cortex and thalamus, consistent with lobar holoprosencephaly. The patient underwent an incisional biopsy of the mass on the second day of life. The mass consisted of normal central nervous tissue with gray and white matter, representing a heterotopic brain. The malformation was considered to be a subcortical heterotopia. With maturity, focal signal changes and decreased cerebral perfusion became clear on brain imaging, suggesting secondary glial degeneration. Coincident with these MRI abnormalities, the child developed psychomotor retardation and severe epilepsy focused on the side of the intracranial mass.

Microbiomes structure and diversity in different horizons of full soil profiles

Science.gov (United States)

Chernov, Timofey; Tkhakakhova, Azida; Zhelezova, Alena; Semenov, Mikhail; Kutovaya, Olga

2017-04-01

Topsoil is a most common object for soil metagenomic studies; sometimes soil profile is being formally split in layers by depth. However, Russian Soil Science School formulated the idea of soil profile as a complex of soil horizons, which can differ in their properties and genesis. In this research we analyzed 57 genetic soil horizons of 8 different soils from European part of Russia: Albeluvisol, Greyzemic Phaeozem, three Chermozems (different land use - till, fallow, wind-protecting tree line), Rhodic Cambisol, Haplic Kastanozem and Salic Solonetz (WRB classification). Sampling was performed from all genetic horizons in each soil profile starting from topsoil until subsoil. Total DNA was extracted and 16S rRNA sequencing was provided together with chemical analysis of soil (pH measurement, C and N contents, etc.). Structure and diversity of prokaryotic community are significantly different in those soil horizons, which chemical properties and processes of origin are contrasting with nearest horizons: Na-enriched horizon of Solonetz, eluvial horizon of Albeluvisol, plough pan of Agrochernozem. Actinobacteria were abundant in top horizons of soils in warm and dry climate, while Acidobacteria had the highest frequency in soils of moist and cold regions. Concerning Archaea, Thaumarchaeota prevailed in all studied soils. Their rate was higher in microbiomes of upper horizons of steppe soils and it was reducing with depth down the profile. Prokaryotic communities in Chernozems were clustered by soil horizons types: microbiomes of A (organic topsoil) and B (mineral) horizons formed non-overlapping clusters by principal component analysis, cluster formed by prokaryotic communities of transitional soil horizons (AB) take place between clusters of A and B horizons. Moreover, prokaryotic communities of A horizons differ from each other strongly, while microbiomes of B horizons formed a narrow small cluster. It must be explaned by more diverse conditions in upper A horizons

Genetic structure and diversity of three Colombian southwest afrodescendent populations using 8 STR's

International Nuclear Information System (INIS)

Guauque Olarte, Sandra; Fuentes Pardo, Angela Patricia; Cardenas Henao, Heiber; Barreto, Guillermo

2010-01-01

To estimate the diversity, structure and genetic flow in three Colombian southwest afrodescendent populations (Buenaventura, Mulalo y Tumaco), the alleles revealed by 8 autosomal STR's were analyzed in 78 no-related individuals, by the use of PCR and comparison with specific allelic ladders for every system resolved by polyacrylamide gel (8%). the results were compared with 2 Amerindian populations (Awa-Kuaikier and Coyaima) and 2 mixed Colombian populations (Valle del Cauca and Cauca). For the afrodescendent and Amerindian populations was found moderate diversity (h between 0.768±0.414 and 0.796±0.424), in contrast, the mixed population showed higher rates (>0.803), which is probably caused by mixing with Amerindians, that also can explain the high endogamy seen in mixed populations. The AMOVA exhibited moderate genetic structure between the afrodescendent populations (FST= 0.098; p<0.05), but higher between the three ethnical groups compared (FST=0.26723; p<0.05). The closer genetics distances are in favor of Tumaco and Buenaventura, supported for the migration rate found (34.298), which was the same inside of Amerindian and mixed populations. Maybe, because Mulalo is a closed isolated population, its differences in front others afrodescendent populations are explained. The neighbor-joining tree showed nearest relations among Amerindian and mixed populations, furthermore, the ancestral character for the afrodescendents. That sustains the idea of genetic flow maintained between the 3 ethnical groups, principally between Amerindian and mixed populations, supported because the genetic differences, migration rates and Amerindian matrilineality reported in the literature

Plasmodium vivax merozoite surface protein-3 alpha: a high-resolution marker for genetic diversity studies.

Science.gov (United States)

Prajapati, Surendra Kumar; Joshi, Hema; Valecha, Neena

2010-06-01

Malaria, an ancient human infectious disease caused by five species of Plasmodium, among them Plasmodium vivax is the most widespread human malaria species and causes huge morbidity to its host. Identification of genetic marker to resolve higher genetic diversity for an ancient origin organism is a crucial task. We have analyzed genetic diversity of P. vivax field isolates using highly polymorphic antigen gene merozoite surface protein-3 alpha (msp-3 alpha) and assessed its suitability as high-resolution genetic marker for population genetic studies. 27 P. vivax field isolates collected during chloroquine therapeutic efficacy study at Chennai were analyzed for genetic diversity. PCR-RFLP was employed to assess the genetic variations using highly polymorphic antigen gene msp-3 alpha. We observed three distinct PCR alleles at msp-3 alpha, and among them allele A showed significantly high frequency (53%, chi2 = 8.22, p = 0.001). PCR-RFLP analysis revealed 14 and 17 distinct RFLP patterns for Hha1 and Alu1 enzymes respectively. Further, RFLP analysis revealed that allele A at msp-3 alpha is more diverse in the population compared with allele B and C. Combining Hha1 and Alu1 RFLP patterns revealed 21 distinct genotypes among 22 isolates reflects higher diversity resolution power of msp-3 alpha in the field isolates. P. vivax isolates from Chennai region revealed substantial amount of genetic diversity and comparison of allelic diversity with other antigen genes and microsatellites suggesting that msp-3 alpha could be a high-resolution marker for genetic diversity studies among P. vivax field isolates.

Genetic diversity and structure related to expansion history and habitat isolation: stone marten populating rural-urban habitats.

Science.gov (United States)

Wereszczuk, Anna; Leblois, Raphaël; Zalewski, Andrzej

2017-12-22

Population genetic diversity and structure are determined by past and current evolutionary processes, among which spatially limited dispersal, genetic drift, and shifts in species distribution boundaries have major effects. In most wildlife species, environmental modifications by humans often lead to contraction of species' ranges and/or limit their dispersal by acting as environmental barriers. However, in species well adapted to anthropogenic habitat or open landscapes, human induced environmental changes may facilitate dispersal and range expansions. In this study, we analysed whether isolation by distance and deforestation, among other environmental features, promotes or restricts dispersal and expansion in stone marten (Martes foina) populations. We genotyped 298 martens from eight sites at twenty-two microsatellite loci to characterize the genetic variability, population structure and demographic history of stone martens in Poland. At the landscape scale, limited genetic differentiation between sites in a mosaic of urban, rural and forest habitats was mostly influenced by isolation by distance. Statistical clustering and multivariate analyses showed weak genetic structuring with two to four clusters and a high rate of gene flow between them. Stronger genetic differentiation was detected for one stone marten population (NE1) located inside a large forest complex. Genetic differentiation between this site and all others was 20% higher than between other sites separated by similar distances. The genetic uniqueness index of NE1 was also twofold higher than in other sites. Past demographic history analyses showed recent expansion of this species in north-eastern Poland. A decrease in genetic diversity from south to north, and MIGRAINE analyses indicated the direction of expansion of stone marten. Our results showed that two processes, changes in species distribution boundaries and limited dispersal associated with landscape barriers, affect genetic diversity and

Effect of the recent land use on the plant diversity and community structure of Omayed Biosphere Reserve, Egypt

Directory of Open Access Journals (Sweden)

Dalia A. Ahmed

2015-07-01

Full Text Available The present study aims at describing and analysing the floristic composition and vegetation types, as well as determining the effect of recent land uses on the vegetation structure. It aims also at identifying the alien plants species and elucidating the impact of these species on the plant diversity and community structure of the study area. One hundred and ninety stands were selected monthly for this study, 145 species were recorded (69 perennials and 76 annuals related to 83 genera, 40 families in 9 identified habitats in El-Omayed Biosphere Reserve (coastal sand dunes, salt marshes, saline depression, non-saline depression, inland ridges, inland plateau, irrigation canals, road sides and cultivated lands. Therophytes were the most represented life form. Three habitat groups resulted after the application of TWINSPAN and DCA as classification and ordination techniques: 2 represented the natural habitats and one represented the urban and cultivated habitats. Group I represented coastal dunes and salt marshes GII: saline depressions, non-saline depressions, inland plateau and inland ridges and GIII: irrigation canals, road sides and cultivated lands. Coastal dunes had the highest species richness (α-diversity, followed by cultivated lands, while inland plateau had the lowest; but saline depressions had the highest species turnover (β-diversity. Non-saline depressions had the highest relative evenness, while saline depressions had the highest relative concentration of dominance. Coastal dunes had highest values of calcium carbonates and calcium ions, and salt marshes had the highest salinity, pH, potassium and sodium contents, but cultivated lands had the highest values of silt, clay and organic matter. The diagram resulting from CCA showed an influence of most soil variables, except nitrogen, calcium and potassium. Twenty two species were recorded for the first time in the study area. The recent land use (overgrazing, wood cutting and

Structural Diversity of Metallosupramolecular Assemblies Based on the Bent Bridging Ligand 4,4′-Dithiodipyridine

Directory of Open Access Journals (Sweden)

Rüdiger W. Seidel

2013-05-01

Full Text Available 4,4′-Dithiodipyridine (dtdp, also termed 4,4′-dipyridyldisulfide, is a bridging ligand of the 4,4′-bipyridine type. The introduction of the disulfide moiety inevitably leads to a relatively rigid angular structure, which exhibits axial chirality. More than 90 metal complexes containing the dtdp ligand have been crystallographically characterised until now. This review focuses on the preparation and structural diversity of discrete and polymeric metallosupramolecular assemblies constructed from dtdp as bridging ligands. These encompass metallamacrocycles with M2L2 topology and coordination polymers with periodicity in one or two dimensions. One-dimensional coordination polymers represent the vast majority of the metallosupramolecular structures obtained from dtdp. These include repeated rhomboids, zigzag, helical and arched chains among other types. In this contribution, we make an attempt to provide a comprehensive account of the structural data that are currently available for metallosupramolecular assemblies based on the bent bridging ligand dtdp.

Genetic Diversity and Structure among Isolated Populations of the Endangered Gees Golden Langur in Assam, India

Science.gov (United States)

Biswas, Jihosuo; Nag, Sudipta; Shil, Joydeep; Umapathy, Govindhaswamy

2016-01-01

Gee’s golden langur (Trachypithecus geei) is an endangered colobine primate, endemic to the semi-evergreen and mixed-deciduous forests of Indo-Bhutan border. During the last few decades, extensive fragmentation has caused severe population decline and local extinction of golden langur from several fragments. However, no studies are available on the impact of habitat fragmentation and the genetic diversity of golden langur in the fragmented habitats. The present study aimed to estimate the genetic diversity in the Indian population of golden langur. We sequenced and analyzed around 500 bases of the mitochondrial DNA (mtDNA) hypervariable region-I from 59 fecal samples of wild langur collected from nine forest fragments. Overall, genetic diversity was high (h = 0.934, π = 0.0244) and comparable with other colobines. Populations in smaller fragments showed lower nucleotide diversity compared to the larger forest fragments. The median-joining network of haplotypes revealed a genetic structure that corresponded with the geographical distribution. The Aie and Champabati Rivers were found to be a barrier to gene flow between golden langur populations. In addition, it also established that T. geei is monophyletic but revealed possible hybridization with capped langur, T. pileatus, in the wild. It is hoped that these findings would result in a more scientific approach towards managing the fragmented populations of this enigmatic species. PMID:27564405

Diverse Planning for UAV Control and Remote Sensing

Directory of Open Access Journals (Sweden)

Jan Tožička

2016-12-01

Full Text Available Unmanned aerial vehicles (UAVs are suited to various remote sensing missions, such as measuring air quality. The conventional method of UAV control is by human operators. Such an approach is limited by the ability of cooperation among the operators controlling larger fleets of UAVs in a shared area. The remedy for this is to increase autonomy of the UAVs in planning their trajectories by considering other UAVs and their plans. To provide such improvement in autonomy, we need better algorithms for generating alternative trajectory variants that the UAV coordination algorithms can utilize. In this article, we define a novel family of multi-UAV sensing problems, solving task allocation of huge number of tasks (tens of thousands to a group of configurable UAVs with non-zero weight of equipped sensors (comprising the air quality measurement as well together with two base-line solvers. To solve the problem efficiently, we use an algorithm for diverse trajectory generation and integrate it with a solver for the multi-UAV coordination problem. Finally, we experimentally evaluate the multi-UAV sensing problem solver. The evaluation is done on synthetic and real-world-inspired benchmarks in a multi-UAV simulator. Results show that diverse planning is a valuable method for remote sensing applications containing multiple UAVs.

Genetic Diversity and Geographic Population Structure of Bovine Neospora caninum Determined by Microsatellite Genotyping Analysis

Science.gov (United States)

Regidor-Cerrillo, Javier; Díez-Fuertes, Francisco; García-Culebras, Alicia; Moore, Dadín P.; González-Warleta, Marta; Cuevas, Carmen; Schares, Gereon; Katzer, Frank; Pedraza-Díaz, Susana; Mezo, Mercedes; Ortega-Mora, Luis M.

2013-01-01

The cyst-forming protozoan parasite Neospora caninum is one of the main causes of bovine abortion worldwide and is of great economic importance in the cattle industry. Recent studies have revealed extensive genetic variation among N . caninum isolates based on microsatellite sequences (MSs). MSs may be suitable molecular markers for inferring the diversity of parasite populations, molecular epidemiology and the basis for phenotypic variations in N . caninum , which have been poorly defined. In this study, we evaluated nine MS markers using a panel of 11 N . caninum -derived reference isolates from around the world and 96 N . caninum bovine clinical samples and one ovine clinical sample collected from four countries on two continents, including Spain, Argentina, Germany and Scotland, over a 10-year period. These markers were used as molecular tools to investigate the genetic diversity, geographic distribution and population structure of N . caninum . Multilocus microsatellite genotyping based on 7 loci demonstrated high levels of genetic diversity in the samples from all of the different countries, with 96 microsatellite multilocus genotypes (MLGs) identified from 108 N . caninum samples. Geographic sub-structuring was present in the country populations according to pairwise F ST. Principal component analysis (PCA) and Neighbor Joining tree topologies also suggested MLG segregation partially associated with geographical origin. An analysis of the MLG relationships, using eBURST, confirmed that the close genetic relationship observed between the Spanish and Argentinean populations may be the result of parasite migration (i.e., the introduction of novel MLGs from Spain to South America) due to cattle movement. The eBURST relationships also revealed genetically different clusters associated with the abortion. The presence of linkage disequilibrium, the co-existence of specific MLGs to individual farms and eBURST MLG relationships suggest a predominant clonal

Molecular genetic diversity and population structure of Ethiopian white lupin landraces: Implications for breeding and conservation

Science.gov (United States)

Yao, Nasser; Martina, Kyalo; Dagne, Kifle; Wegary, Dagne; Tesfaye, Kassahun

2017-01-01

White lupin is one of the four economically important species of the Lupinus genus and is an important grain legume in the Ethiopian farming system. However, there has been limited research effort to characterize the Ethiopian white lupin landraces. Fifteen polymorphic simple sequence repeat (SSR) markers were used to assess the genetic diversity and population structure of 212 Ethiopian white lupin (Lupinus albus) landraces and two genotypes from different species (Lupinus angustifolius and Lupinus mutabilis) were used as out-group. The SSR markers revealed 108 different alleles, 98 of them from 212 landraces and 10 from out-group genotypes, with an average of 6.5 alleles per locus. The average gene diversity was 0.31. Twenty eight landraces harbored one or more private alleles from the total of 28 private alleles identified in the 212 white lupin accessions. Seventy-seven rare alleles with a frequency of less than 5% were identified and accounted for 78.6% of the total alleles detected. Analysis of molecular variance (AMOVA) showed that 92% of allelic diversity was attributed to individual accessions within populations while only 8% was distributed among populations. At 70% similarity level, the UPGMA dendrogram resulted in the formation of 13 clusters comprised of 2 to 136 landraces, with the out-group genotypes and five landraces remaining distinct and ungrouped. Population differentiation and genetic distance were relatively high between Gondar and Ethiopian white lupin populations collected by Australians. A model-based population structure analysis divided the white lupin landraces into two populations. All Ethiopian white lupin landrace populations, except most of the landraces collected by Australians (77%) and about 44% from Awi, were grouped together with significant admixtures. The study also suggested that 34 accessions, as core collections, were sufficient to retain 100% of SSR diversity. These accessions (core G-34) represent 16% of the whole 212

Diverse Cd(II) compounds based on N-benzoyl-L-glutamic acid and N-donor ligands: Structures and photoluminescent properties

International Nuclear Information System (INIS)

Ma, Ning; Guo, Wei-Ying; Song, Hui-Hua; Yu, Hai-Tao

2016-01-01

Five new Cd(II) coordination polymers with N-benzoyl-L-glutamic acid (H_2bzgluO) and different N-donor ligands, [Cd(bzgluO)(2,2′-bipy)(H_2O)]_n (1), [Cd(bzgluO)(2,4′-bipy)_2(H_2O)·3H_2O]_n (2), [Cd(bzgluO)(phen)·H_2O]_n (3), [Cd(bzgluO)(4,4′-bipy)(H_2O)]_n (4), [Cd(bzgluO)(bpp)(H_2O)·2H_2O]_n (5) were synthesized (2,2′-bipy=2,2′-bipyridine, 2,4′-bipy=2,4′-bipyridine, phen=1,10-phenanthroline, 4,4′-bipy=4,4′-bipyridine, bpp=1,3-di(4-pyridyl)propane). Compounds 1–2 exhibit a 1D single-chain structure. Compound 1 generates a 2D supramolecular structure via π–π stacking and hydrogen bonding, 3D architecture of compound 2 is formed by hydrogen bonding. Compound 3 features a 1D double-chain structure, which are linked by π–π interactions into a 2D supramolecular layer. Compounds 4-5 display a 2D network structure. Neighboring layers of 4 are extended into a 3D supramolecular architecture through hydrogen bonding. The structural diversity of these compounds is attributed to the effect of ancillary N-donor ligands and coordination modes of H_2bzgluO. Luminescent properties of 1–5 were studied at room temperature. Circular dichroism of compounds 1, 2 and 5 were investigated. - Graphical abstract: Five new Cd(II) metal coordination compounds with H_2bzgluO and different N-donor ligands were synthesized and characterized. Compounds 1, 2 and 3 present 1D structures, compounds 4 and 5 display 2D networks. Results indicate that auxiliary ligands and coordination modes of H_2bzgluO play an important role in governing the formation of final frameworks, and the hydrogen-bonding and π–π stacking interactions contribute the formation of the diverse supramolecular architectures. Furthermore, the different crystal structures influence the emission spectra significantly. - Highlights: • It is rarely reported that complexes prepared with N-benzoyl-L-glutamic acid. • Each complex displays diverse structures and different supramolecular

Structural Analysis of Insulin Minisatellite Alleles Reveals Unusually Large Differences in Diversity between Africans and Non-Africans

Science.gov (United States)

Stead, John D. H.; Jeffreys, Alec J.

2002-01-01

The insulin minisatellite (INS VNTR) associates with susceptibility to a variety of diseases. We have developed a high-resolution system for analyzing variant repeat distributions applicable to all known minisatellite alleles, irrespective of size, which allows lineages of related alleles to be identified. This system has previously revealed extremely low structural diversity in the minisatellite among northern Europeans from the United Kingdom, with all alleles belonging to one of only three highly diverged lineages called “I,” “IIIA,” and “IIIB.” To explore the origins of this remarkably limited lineage diversity, we have characterized an additional 780 alleles from three non-African and three African populations. In total, 22 highly diverged lineages were identified, with structural intermediates absent from extant populations, suggesting a bottleneck within the ancestry of all humans. The difference between levels of diversity in Africans and non-Africans is unusually large, with all 22 lineages identified in Africa compared with only three lineages seen not only in the United Kingdom but also in the other non-African populations. We also find evidence for overrepresentation of lineage I chromosomes in non-Africans. These data are consistent with a common out-of-Africa origin and an unusually tight bottleneck within the ancestry of all non-African populations, possibly combined with differential and positive selection for lineage I alleles in non-Africans. The important implications of these data for future disease-association studies are discussed. PMID:12404181

Stress analysis of partial sphere used for bottom shell of off-shore structure

International Nuclear Information System (INIS)

Nishimaki, Ko; Matsumoto, Kohei; Hori, Tohru; Takeshita, Haruyuki; Iwata, Setsuo

1976-01-01

In the near future, various huge off-shore structures will be constructed. Concrete shall become a leading material in the structures, owing to its versatile properties. One of the limitations of concrete is its low tensile strength. The problem of low tensile strength of concrete is dealt with in main by two different methods: by applying prestressing and by designing the structural configuration so that no tensile stresses appear. In the paper, the authors discuss the application of partially spherical shell to huge off-shore structures. Structural analysis by using the finite element method were done in order to investigate the feasibility of the structure. The results were arranged as to certain parameters to derive design charts by which the stresses of check points can be presumed. Optimum shape is also discussed. (auth.)

En bloc resection of huge cemento-ossifying fibroma of mandible: avoiding lower lip split incision.

Science.gov (United States)

Ayub, Tahera; Katpar, Shahjahan; Shafique, Salman; Mirza, Talat

2011-05-01

Cemento-ossifying Fibroma (COF) is an osteogenic benign neoplasm affecting the jaws and other craniofacial bones. It commonly presents as a progressively slow growing pathology, which can sometimes attain an enormous size, causing facial deformity. A case of a huge cemento-ossifying fibroma, appearing as a mandibular dumbell tumour in a male patient is documented, which caused massive bone destruction and deformity. It was surgically removed by performing en bloc resection of mandible avoiding the splitting of lower lip incision technique, thereby maintaining his normal facial appearance.

The taxonomic and functional diversity of microbes at a temperate coastal site: a 'multi-omic' study of seasonal and diel temporal variation.

Directory of Open Access Journals (Sweden)

Jack A Gilbert

Full Text Available How microbial communities change over time in response to the environment is poorly understood. Previously a six-year time series of 16S rRNA V6 data from the Western English Channel demonstrated robust seasonal structure within the bacterial community, with diversity negatively correlated with day-length. Here we determine whether metagenomes and metatranscriptomes follow similar patterns. We generated 16S rRNA datasets, metagenomes (1.2 GB and metatranscriptomes (157 MB for eight additional time points sampled in 2008, representing three seasons (Winter, Spring, Summer and including day and night samples. This is the first microbial 'multi-omic' study to combine 16S rRNA amplicon sequencing with metagenomic and metatranscriptomic profiling. Five main conclusions can be drawn from analysis of these data: 1 Archaea follow the same seasonal patterns as Bacteria, but show lower relative diversity; 2 Higher 16S rRNA diversity also reflects a higher diversity of transcripts; 3 Diversity is highest in winter and at night; 4 Community-level changes in 16S-based diversity and metagenomic profiles are better explained by seasonal patterns (with samples closest in time being most similar, while metatranscriptomic profiles are better explained by diel patterns and shifts in particular categories (i.e., functional groups of genes; 5 Changes in key genes occur among seasons and between day and night (i.e., photosynthesis; but these samples contain large numbers of orphan genes without known homologues and it is these unknown gene sets that appear to contribute most towards defining the differences observed between times. Despite the huge diversity of these microbial communities, there are clear signs of predictable patterns and detectable stability over time. Renewed and intensified efforts are required to reveal fundamental deterministic patterns in the most complex microbial communities. Further, the presence of a substantial proportion of orphan

Analysis of molecular diversity, population structure and linkage disequilibrium in a worldwide survey of cultivated barley germplasm (Hordeum vulgare L.

Directory of Open Access Journals (Sweden)

Ganal Martin W

2006-01-01

Full Text Available Abstract Background The goal of our study was a systematic survey of the molecular diversity in barley genetic resources. To this end 953 cultivated barley accessions originating from all inhabited continents except Australia were genotyped with 48 SSR markers. Molecular diversity was evaluated with routine statistics (allelic richness, gene diversity, allele frequency, heterozygosity and unique alleles, Principal Coordinate Analysis (PCoA, and analysis of genome-wide linkage disequilibrium. Results A genotyping database for 953 cultivated barley accessions profiled with 48 SSR markers was established. The PCoA revealed structuring of the barley population with regard to (i geographical regions and (ii agronomic traits. Geographic origin contributed most to the observed molecular diversity. Genome-wide linkage disequilibrium (LD was estimated as squared correlation of allele frequencies (r2. The values of LD for barley were comparable to other plant species (conifers, poplar, maize. The pattern of intrachromosomal LD with distances between the genomic loci ranging from 1 to 150 cM revealed that in barley LD extended up to distances as long as 50 cM with r2 > 0.05, or up to 10 cM with r2 > 0.2. Few loci mapping to different chromosomes showed significant LD with r2 > 0.05. The number of loci in significant LD as well as the pattern of LD were clearly dependent on the population structure. The LD in the homogenous group of 207 European 2-rowed spring barleys compared to the highly structured worldwide barley population was increased in the number of loci pairs with r2 > 0.05 and had higher values of r2, although the percentage of intrachromosomal loci pairs in significant LD based on P 0.80 provided higher LD values as compared to 19 low polymorphic loci (PIC Conclusion A global population of cultivated barley accessions was highly structured. Clustering highlighted the accessions with the same geographic origin, as well as accessions possessing

Forest structure, diversity and regeneration potential along altitudinal gradient in Dhanaulti of Garhwal Himalaya

Energy Technology Data Exchange (ETDEWEB)

Saha, S.; Rajwar, G.S.; Kumar, M.

2016-07-01

Aim of the study: The aim of the present study was to understatnd the forest composition, structure, diversity and regeneration potential along altitudinal gradient. Area of study: The study was carried out in Dhanaulti forest which falls under temperate region of Garhwal Himalaya in Uttarakhand state, India. Material and Methods: Vegetation analysis was carried out using 10 quadrats at each altitude using a quadrate size of 10×10 m2. In each quadrate, categories of trees >30 cm cbh were considered as trees, 10-30cm cbh as saplings and <10 cm cbh as seedlings. The data were quantitatively analyzed. Main results: In upper and middle altitudes, Cedrus deodara was reported dominant tree whereas, in lower altitude Quercus leucotrichophora was reported dominant. Tree density was highest in lower altitude which reduced middle and upper altitudes whereas, total basal cover increased with increasing altitude. The increasing total basal cover with altitude could be because of the presence of Cedrus deodara trees having higher girth classes. In tree, sapling and seedling layers, diversity (H) and equitabiltiy (EC) decreased with increasing altitude. However, concentrations of dominace (CD) and beta diversity (BD have shown reverse trend with H and EC which increased with increasing altitudes, in each layer of tree, sapling and seedling. The distribution pattern of most species in all layers of trees, saplings and seedlings was contagious. The regeneration potential of the species has shown that some of the species in the absence of tree layer are still regenerating particularly, Rhododendron arboreum, Benthamidia capitata, Neolitsea pallens etc. It indicates that most of the species are shifting upward as they are getting suitable conditions. Research highlights: Altitude influence species composition, diversity and regeneration potential of species. (Author)

[Effect of ground mulch managements on soil bacterial community structure and diversity in the non-irrigated apple orchard in Weibei Loess Plateau].

Science.gov (United States)

Chen, Yuexing; Wen, Xiaoxia; Sun, Yulin; Zhang, Junli; Lin, Xiaoli; Liao, Yuncheng

2015-07-04

We studied the changes in soil bacterial communities induced by ground mulch managements at different apple growth periods. We adopted the denaturing gradient gel electrophoresis (DGGE) with PCR-amplified 16S rRNA fragments to determine soil bacterial community structure and diversity. Soil bacterial community structure with different ground mulch managements were significantly different. Both the mulch management strategies and apple growth periods affected the predominant groups and their abundance in soil bacterial communities. Grass mulch and cornstalk mulch treatments had higher bacterial diversity and richness than the control at young fruit period and fruit expanding period, whereas film mulch treatment had no significant difference compared with the control. During mature period, bacterial diversity in the control reached its maximum, which may be ascribed to the rapid growth and reproduction of the r-selection bacteria. The clustering and detrended correspondence analysis revealed that differences in soil bacterial communities were closely correlated to apple growth periods and ground mulch managements. Soil samples from the grass mulch and cornstalk mulch treatments clustered together while those mulched with plastic film treatment were similar to the control. The most abundant phylum in soil bacterial community was Proteobacteria followed by Bacteroidetes. Some other phyla were also detected, such as Acidobacteria, Firmicutes, Actinobacteria and Chloroflexi. Mulching with plant (Grass/Cornstalk) had great effects on soil bacterial community structure and enhanced the diversity while film mulch management had no significant effects.

Primary production and algae diversity vs. pollution in xochimilco wet-lands

Energy Technology Data Exchange (ETDEWEB)

Pedroza-Pichardo, R.; Hernandez-Delgadillo, R.; Boll-Arguello, G.

2009-07-01

Xochimilco is an ancient endorheic lake located in the Valley of Mexico. Due to its shallow water and the freshwater springs that lined the canals, they are surround raised agricultural fields called chinampas. Since the Valley of Mexico was originally wetlands, the chinampas were the most productive means of agricultural production. Xochimilco are considered one of the most important urban lungs in Mexico City. However, it is not clear how the huge urbanization around is to know if there is a correlation between primary production (PP), algae diversity, BOD{sub 5} and faecal coliforms. Sample collection was done every month over a year at six different canals named: Embarcadero Celada, Embarcadero Nuevo Nativitas, Canal Las Abejas, Canal Zacapa, Canal Santo Domingo y Canal Nacional. (Author)

Primary production and algae diversity vs. pollution in xochimilco wet-lands

International Nuclear Information System (INIS)

Pedroza-Pichardo, R.; Hernandez-Delgadillo, R.; Boll-Arguello, G.

2009-01-01

Xochimilco is an ancient endorheic lake located in the Valley of Mexico. Due to its shallow water and the freshwater springs that lined the canals, they are surround raised agricultural fields called chinampas. Since the Valley of Mexico was originally wetlands, the chinampas were the most productive means of agricultural production. Xochimilco are considered one of the most important urban lungs in Mexico City. However, it is not clear how the huge urbanization around is to know if there is a correlation between primary production (PP), algae diversity, BOD 5 and faecal coliforms. Sample collection was done every month over a year at six different canals named: Embarcadero Celada, Embarcadero Nuevo Nativitas, Canal Las Abejas, Canal Zacapa, Canal Santo Domingo y Canal Nacional. (Author)

A temporal assessment of nematode community structure and diversity in the rhizosphere of cisgenic Phytophthora infestans-resistant potatoes.

Science.gov (United States)

Ortiz, Vilma; Phelan, Sinead; Mullins, Ewen

2016-12-01

Nematodes play a key role in soil processes with alterations in the nematode community structure having the potential to considerably influence ecosystem functioning. As a result fluctuations in nematode diversity and/or community structure can be gauged as a 'barometer' of a soil's functional biodiversity. However, a deficit exists in regards to baseline knowledge and on the impact of specific GM crops on soil nematode populations and in particular in regard to the impact of GM potatoes on the diversity of nematode populations in the rhizosphere. The goal of this project was to begin to address this knowledge gap in regards to a GM potato line, cisgenically engineered for resistance to Phytophthora infestans (responsible organism of the Irish potato famine causing late blight disease). For this, a 3 year (2013, 2014, 2015) field experimental study was completed, containing two conventional genotypes (cvs. Desiree and Sarpo Mira) and a cisgenic genotype (cv. Desiree + Rpi-vnt1). Each potato genotype was treated with different disease management strategies (weekly chemical applications and corresponding no spray control). Hence affording the opportunity to investigate the temporal impact of potato genotype, disease management strategy (and their interaction) on the potato rhizosphere nematode community. Nematode structure and diversity were measured through established indices, accounts and taxonomy with factors recording a significant effect limited to the climatic conditions across the three seasons of the study and chemical applications associated with the selected disease management strategy. Based on the metrics studied, the cultivation of the cisgenic potato genotype exerted no significant effect (P > 0.05) on nematode community diversity or structure. The disease management treatments led to a reduction of specific trophic groups (e.g. Predacious c-p = 4), which of interest appeared to be counteracted by a potato genotype with vigorous growth phenotype

Anthraquinones and Derivatives from Marine-Derived Fungi: Structural Diversity and Selected Biological Activities

Directory of Open Access Journals (Sweden)

Mireille Fouillaud

2016-03-01

Full Text Available Anthraquinones and their derivatives constitute a large group of quinoid compounds with about 700 molecules described. They are widespread in fungi and their chemical diversity and biological activities recently attracted attention of industries in such fields as pharmaceuticals, clothes dyeing, and food colorants. Their positive and/or negative effect(s due to the 9,10-anthracenedione structure and its substituents are still not clearly understood and their potential roles or effects on human health are today strongly discussed among scientists. As marine microorganisms recently appeared as producers of an astonishing variety of structurally unique secondary metabolites, they may represent a promising resource for identifying new candidates for therapeutic drugs or daily additives. Within this review, we investigate the present knowledge about the anthraquinones and derivatives listed to date from marine-derived filamentous fungi′s productions. This overview highlights the molecules which have been identified in microorganisms for the first time. The structures and colors of the anthraquinoid compounds come along with the known roles of some molecules in the life of the organisms. Some specific biological activities are also described. This may help to open doors towards innovative natural substances.

Anthraquinones and Derivatives from Marine-Derived Fungi: Structural Diversity and Selected Biological Activities.

Science.gov (United States)

Fouillaud, Mireille; Venkatachalam, Mekala; Girard-Valenciennes, Emmanuelle; Caro, Yanis; Dufossé, Laurent

2016-03-25

Anthraquinones and their derivatives constitute a large group of quinoid compounds with about 700 molecules described. They are widespread in fungi and their chemical diversity and biological activities recently attracted attention of industries in such fields as pharmaceuticals, clothes dyeing, and food colorants. Their positive and/or negative effect(s) due to the 9,10-anthracenedione structure and its substituents are still not clearly understood and their potential roles or effects on human health are today strongly discussed among scientists. As marine microorganisms recently appeared as producers of an astonishing variety of structurally unique secondary metabolites, they may represent a promising resource for identifying new candidates for therapeutic drugs or daily additives. Within this review, we investigate the present knowledge about the anthraquinones and derivatives listed to date from marine-derived filamentous fungi's productions. This overview highlights the molecules which have been identified in microorganisms for the first time. The structures and colors of the anthraquinoid compounds come along with the known roles of some molecules in the life of the organisms. Some specific biological activities are also described. This may help to open doors towards innovative natural substances.

Genetic diversity and population structure of Brassica oleracea germplasm in Ireland using SSR markers.

Science.gov (United States)

El-Esawi, Mohamed A; Germaine, Kieran; Bourke, Paula; Malone, Renee

2016-01-01

The most economically important Brassica oleracea species is endangered in Ireland, with no prior reported genetic characterization studies. This study assesses the genetic diversity, population structure and relationships of B. oleracea germplasm in Ireland using microsatellite (SSRs) markers. A total of 118 individuals from 25 accessions of Irish B. oleracea were genotyped. The SSR loci used revealed a total of 47 alleles. The observed heterozygosity (0.699) was higher than the expected one (0.417). Moreover, the average values of fixation indices (F) were negative, indicating excess of heterozygotes in all accessions. Polymorphic information content (PIC) values of SSR loci ranged from 0.27 to 0.66, with an average of 0.571, and classified 10 loci as informative markers (PIC>0.5) to differentiate among the accessions studied. The genetic differentiation among accessions showed that 27.1% of the total genetic variation was found among accessions, and 72.9% of the variation resided within accessions. The averages of total heterozygosity (H(T)) and intra-accession genetic diversity (H(S)) were 0.577 and 0.442, respectively. Cluster analysis of SSR data distinguished among kale and Brussels sprouts cultivars. This study provided a new insight into the exploitation of the genetically diverse spring cabbages accessions, revealing a high genetic variation, as potential resources for future breeding programs. SSR loci were effective for differentiation among the accessions studied. Copyright © 2016 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Differential effects of historical migration, glaciations and human impact on the genetic structure and diversity of the mountain pasture weed Veratrum album L

DEFF Research Database (Denmark)

Treier, Urs; Müller-Schärer, H.

2011-01-01

Aim  Today’s genetic population structure and diversity of species can be understood as the result of range expansion from the area of origin, past climatic oscillations and contemporary processes. We examined the relative importance of these factors in Veratrum album L., a toxic weed of mountain...... grasslands. Location  Continental Europe. Methods  Forty populations from the Asian border (Urals and Caucasus) to Portugal were studied using amplified fragment length polymorphisms (AFLPs) combined with selected plant and population measures. The data were analysed with phylogenetic, population genetic...... and regression methods inferring both genetic structure and diversity from geographic and ecological factors. Results  Fragment frequency clines together with genetic distance clustering and principal coordinates analysis indicated an east–west direction in the genetic structure of V. album, suggesting ancient...

Superposition model analysis of nickel(II) ions in trigonal bipyramidal complexes exhibiting huge zero field splitting (aka ‘giant magnetic anisotropy’)

Energy Technology Data Exchange (ETDEWEB)

Rudowicz, Czesław, E-mail: crudowicz@zut.edu.pl [Faculty of Chemistry, A. Mickiewicz University, 61-614 Poznań (Poland); Institute of Physics, West Pomeranian University of Technology, Szczecin (Poland); Açıkgöz, Muhammed [Department of Chemistry, Rutgers University, Newark, New Jersey 07102 (United States); Gnutek, Paweł [Institute of Physics, West Pomeranian University of Technology, Szczecin (Poland)

2017-07-15

Graphical abstract: Using crystal structure data for [Ni(Me{sub 6}tren)Cl](ClO{sub 4}) and [Ni(Me{sub 6}tren)Br](Br) as well as taking into account the Jahn-Teller distortions of five-fold coordinated Ni-complexes revealed by DFT geometry optimization, the ZFSPs are predicted for several structural models and wide ranges of model parameters. - Highlights: • Semiempirical study of potential SMM [Ni(Me{sub 6}tren)Cl](ClO{sub 4}) and [Ni(Me{sub 6}tren)Br](Br). • Superposition model analysis of zero field splitting (ZFS) parameters carried out. • Jahn-Teller distortions revealed by DFT geometry optimization considered. • SPM predicts D(ZFS) of observed magnitudes with positive or negative signs. • Results corroborate giant ZFS, which shall not be equated with magnetic anisotropy. - Abstract: Potential single-ion magnet Ni{sup 2+} systems: [Ni(Me{sub 6}tren)Cl](ClO{sub 4}) and [Ni(Me{sub 6}tren)Br](Br) reveal unusually high zero field splitting (ZFS). The ZFS parameter (ZFSP) D{sub expt} = −120 to −180 cm{sup −1} was determined indirectly by high-magnetic field, high-frequency electron magnetic resonance (HMF-EMR). Modeling ZFSPs using the density functional theory (DFT) codes predicts D values: −100 to −200 cm{sup −1}. Such ZFSP values may seem controversial in view of the D values usually not exceeding several tens of cm{sup −1} for Ni{sup 2+} ions. To corroborate or otherwise these results and elucidate the origin of the huge ZFS (named inappropriately as ‘giant uniaxial magnetic anisotropy’) and respective wavefunctions, we have undertaken semiempirical modeling based on the crystal field (CF) and spin Hamiltonians (SH) theory. In this paper, a feasibility study is carried out to ascertain if superposition model (SPM) calculations may yield such huge D values for these Ni{sup 2+} systems. Using crystal structure data for [Ni(Me{sub 6}tren)Cl](ClO{sub 4}) and [Ni(Me{sub 6}tren)Br](Br) as well as taking into account the Jahn

[A Case of Huge Colon Cancer Accompanied with Severe Hypoproteinemia].

Science.gov (United States)

Hiraki, Sakurao; Kanesada, Kou; Harada, Toshio; Tada, Kousuke; Fukuda, Shintaro

2017-11-01

We report a case of huge colon cancer accompanied with severe hypoproteinemia. A7 4-year-old woman was referred to our hospital because of abdominal fullness. Blood examinations revealed anemia(hemoglobin 8.8 g/dL)and sever hypopro- teinemia(total protein 4.5 g/dL, albumin 1.1 g/dL). Computed tomography examination of abdomen revealed ascites and large tumor(12.5×10.5 cm)at the right side colon. By further examinations ascending colon cancer without distant metastasis was diagnosed, then we performed right hemicolectomy and primary intestinal anastomosis by open surgery. Ahuge type 1 tumor(18×12 cm)was observed in the excised specimen, which invaded to terminal ileum directly. The tumor was diagnosed moderately differentiated adenocarcinoma without lymph node metastasis(pT3N0M0, fStage II ). Postoperative course was uneventful and serum protein concentration recovered gradually to normal range. Protein leakage from the tumor cannot be proved by this case, so we can't diagnose as protein-losing enteropathy, but we strongly doubt this etiology from postoperative course in this case.

pH dominates variation in tropical soil archaeal diversity and community structure.

Science.gov (United States)

Tripathi, Binu M; Kim, Mincheol; Lai-Hoe, Ang; Shukor, Nor A A; Rahim, Raha A; Go, Rusea; Adams, Jonathan M

2013-11-01

Little is known of the factors influencing soil archaeal community diversity and composition in the tropics. We sampled soils across a range of forest and nonforest environments in the equatorial tropics of Malaysia, covering a wide range of pH values. DNA was PCR-amplified for the V1-V3 region of the 16S rRNA gene, and 454-pyrosequenced. Soil pH was the best predictor of diversity and community composition of Archaea, being a stronger predictor than land use. Archaeal OTU richness was highest in the most acidic soils. Overall archaeal abundance in tropical soils (determined by qPCR) also decreased at higher pH. This contrasts with the opposite trend previously found in temperate soils. Thaumarcheota group 1.1b was more abundant in alkaline soils, whereas group 1.1c was only detected in acidic soils. These results parallel those found in previous studies in cooler climates, emphasizing niche conservatism among broad archaeal groups. Among the most abundant operational taxonomic units (OTUs), there was clear evidence of niche partitioning by pH. No individual OTU occurred across the entire range of pH values. Overall, the results of this study show that pH plays a major role in structuring tropical soil archaeal communities. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Genetic diversity and species diversity of stream fishes covary across a land-use gradient

Science.gov (United States)

Blum, M.J.; Bagley, M.J.; Walters, D.M.; Jackson, S.A.; Daniel, F.B.; Chaloud, D.J.; Cade, B.S.

2012-01-01

Genetic diversity and species diversity are expected to covary according to area and isolation, but may not always covary with environmental heterogeneity. In this study, we examined how patterns of genetic and species diversity in stream fishes correspond to local and regional environmental conditions. To do so, we compared population size, genetic diversity and divergence in central stonerollers (Campostoma anomalum) to measures of species diversity and turnover in stream fish assemblages among similarly sized watersheds across an agriculture-forest land-use gradient in the Little Miami River basin (Ohio, USA). Significant correlations were found in many, but not all, pair-wise comparisons. Allelic richness and species richness were strongly correlated, for example, but diversity measures based on allele frequencies and assemblage structure were not. In-stream conditions related to agricultural land use were identified as significant predictors of genetic diversity and species diversity. Comparisons to population size indicate, however, that genetic diversity and species diversity are not necessarily independent and that variation also corresponds to watershed location and glaciation history in the drainage basin. Our findings demonstrate that genetic diversity and species diversity can covary in stream fish assemblages, and illustrate the potential importance of scaling observations to capture responses to hierarchical environmental variation. More comparisons according to life history variation could further improve understanding of conditions that give rise to parallel variation in genetic diversity and species diversity, which in turn could improve diagnosis of anthropogenic influences on aquatic ecosystems. ?? 2011 Springer-Verlag.

Genetic diversity and population structure of the New World screwworm fly from the Amazon region of Brazil.

Science.gov (United States)

Mastrangelo, Thiago; Fresia, Pablo; Lyra, Mariana L; Rodrigues, Rosangela A; Azeredo-Espin, Ana Maria L

2014-10-01

Cochliomyia hominivorax (Coquerel) is a myiasis fly that causes economic losses to livestock farmers in warmer American regions. Previous studies of this pest had found population structure at north and south of the Amazon Basin, which was considered to be a barrier to dispersal. The present study analyzed three mitochondrial DNA (mtDNA) markers and eight nuclear microsatellite loci to investigate for the first time the genetic diversity and population structure across the Brazilian Amazon region (Amazonia). Both mtDNA and microsatellite data supported the existence of much diversity and significant population structure among nine regional populations of C. hominivorax, which was found to be surprisingly common in Amazonia. Forty-six mtDNA haplotypes were identified, of which 39 were novel and seven had previously been found only at south of Amazonia. Seventy microsatellite alleles were identified by size, moderate to high values of heterozygosity were discovered in all regions, and a Bayesian clustering analysis identified four genetic groups that were not geographically distributed. Reproductive compatibility was also investigated by laboratory crossing, but no evidence of hybrid dysgenesis was found between an Amazonian colony and one each of from Northeast and Southeast Brazil. The results have important implications for area-wide control by the Sterile Insect Technique. Copyright © 2014 International Atomic Energy Agency 2014. Published by Elsevier B.V. All rights reserved.

Genetic diversity and population structure of the Guinea pig (Cavia porcellus, Rodentia, Caviidae) in Colombia.

Science.gov (United States)

Burgos-Paz, William; Cerón-Muñoz, Mario; Solarte-Portilla, Carlos

2011-10-01

The aim was to establish the genetic diversity and population structure of three guinea pig lines, from seven production zones located in Nariño, southwest Colombia. A total of 384 individuals were genotyped with six microsatellite markers. The measurement of intrapopulation diversity revealed allelic richness ranging from 3.0 to 6.56, and observed heterozygosity (Ho) from 0.33 to 0.60, with a deficit in heterozygous individuals. Although statistically significant (p guinea-pig lines and populations, coincided with the historical and geographical distribution of the populations. Likewise, high genetic identity between improved and native lines was established. An analysis of group probabilistic assignment revealed that each line should not be considered as a genetically homogeneous group. The findings corroborate the absorption of native genetic material into the improved line introduced into Colombia from Peru. It is necessary to establish conservation programs for native-line individuals in Nariño, and control genealogical and production records in order to reduce the inbreeding values in the populations.

plant diversity, vegetation structure and relationship between plant

African Journals Online (AJOL)

Preferred Customer

patterns of plant diversity were evaluated on the basis of species richness as the total number ... threatened due to habitat conversion, loss, and ... the conservation of highland forest bird species .... the economic and social welfare of the rural.

Investigation of weed species diversity and community structure in saffron fields of Khorasan

Directory of Open Access Journals (Sweden)

Surur Khorramdel

2017-09-01

Full Text Available Weedy flora of agroecosystems is composed of many species that have evolved in response to cropping system practices by occupying the niches left available in agroecosystems. In order to study weed species diversity and community structure in the saffron fields of Khorasan province, a survey trial was carried out in seven counties (including Mashhad, Neyshabur, Birjandn, Ghaen, Gonabad, Torbat-e Jam and Torbat-e Heydari during 2014 and 2015 from vegetative growth, dormant to flowering stages of saffron randomly dropped 1×1 m2 quadrates in 50 fields based on a systematic method as W pattern. The counties were clustered by the hierarchical complete linkage method based on Euclidean. Biodiversity indices such as stability coefficient, Simpson, Shannon–Wiener, Margalef and Menhinick were computed. The results indicated that the dominant weeds in saffron fields belong to 19 families and 50 species. Poaceae, Brassicaceae, Asteraceae and Fabaceae were dominant families with 11, 9, 8 and 6 species, respectively. The majority of weed species were dicotyledonous, C3, noxious and annual plants. The highest stability coefficients in the stages of growth of saffron were calculated in Alhagi camelorum, Avena fatua and Achillea millefolium to be 30.81, 24.11 and 12.14, respectively. All weed species except for Alhagi camelorum (sustainable species and Avena fatua (temporary species were recognized as causal species. The maximum diversity indices for weed species were recorded at the vegetative phase of saffron. Correlation coefficient between weed density and yield loss of saffron was computed as R2=0.98. Based on diversity indices for weed species, different counties were clustered in three groups at 75% similarity level.

Temporal Control over Transient Chemical Systems using Structurally Diverse Chemical Fuels.

Science.gov (United States)

Chen, Jack L-Y; Maiti, Subhabrata; Fortunati, Ilaria; Ferrante, Camilla; Prins, Leonard J

2017-08-25

The next generation of adaptive, intelligent chemical systems will rely on a continuous supply of energy to maintain the functional state. Such systems will require chemical methodology that provides precise control over the energy dissipation process, and thus, the lifetime of the transiently activated function. This manuscript reports on the use of structurally diverse chemical fuels to control the lifetime of two different systems under dissipative conditions: transient signal generation and the transient formation of self-assembled aggregates. The energy stored in the fuels is dissipated at different rates by an enzyme, which installs a dependence of the lifetime of the active system on the chemical structure of the fuel. In the case of transient signal generation, it is shown that different chemical fuels can be used to generate a vast range of signal profiles, allowing temporal control over two orders of magnitude. Regarding self-assembly under dissipative conditions, the ability to control the lifetime using different fuels turns out to be particularly important as stable aggregates are formed only at well-defined surfactant/fuel ratios, meaning that temporal control cannot be achieved by simply changing the fuel concentration. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Leadership in diversity.

Science.gov (United States)

Hunt, P L

1994-12-01

As principal change agents, healthcare leaders are well positioned to integrate diversity into their institutions' organizational structure. Thus healthcare leaders must be competent in handling diversity issues. Diversity refers to any characteristic that helps shape a person's attitudes, behaviors, perspective, and interpretation of what is "normal." In the healthcare ministry, diversity encompasses the cultural differences that can be found across functions or among organizations when they merge or partner. Managers and supervisors will have to be familiar with the nuances of diversity if they are to be effective. Those managers who are not adept at incorporating diversity into human resource management may incorrectly evaluate subordinates' capabilities and provide inappropriate training or supervision. As a result, some employees may be underutilized. Others may resist needed direction, overlook instructions, or hide problems such as a language barrier. If executives, marketers, and strategic planners are to develop relevant healthcare services that take into account the needs of their constituencies, they will need to determine how different groups understand and access healthcare. Healthcare leaders who know how to uncover cultural dynamics and challenge cultural assumptions will go far in enabling their staff and managers to confront personal attitudes about community residents. Ultimately, quality of service delivery will be improved.

Using Simpson's diversity index to examine multidimensional models of diversity in health professions education.

Science.gov (United States)

McLaughlin, Jacqueline E; McLaughlin, Gerald W; McLaughlin, Josetta S; White, Carla Y

2016-01-03

This study explored new models of diversity for health professions education that incorporate multiple attributes and examined differences in diversity based on urbanicity, geographic region, and institutional structure. Simpson's Diversity Index was used to develop race, gender, and interprofessional diversity indices for health professions schools in the United States (N = 318). Sullivan's extension was used to develop a composite diversity index that incorporated multiple individual attributes for each school. Pearson's r was used to investigate correlations between continuous variables. ANOVA and independent t-tests were used to compare groups based on urbanicity, geographic region, and Basic Carnegie Classification. Mean (SD) for race, gender, and interprofessional diversity indices were 0.36(0.17), 0.45(0.07), and 0.22(0.27) respectively. All correlations between the three indices were weak. The composite diversity index for this sample was 0.34(0.13). Significant differences in diversity were found between institutions based on urbanicity, Basic Carnegie Classification, and geographic region. Multidimensional models provide support for expanding measures of diversity to include multiple characteristics and attributes. The approach demonstrated in this study enables institutions to complement and extend traditional measures of diversity as a means of providing evidence for decision-making and progress towards institutional initiatives.

Best Practices for Managing Organizational Diversity

Energy Technology Data Exchange (ETDEWEB)

Kreitz, Patricia A.; /SLAC

2007-05-18

In the twentieth century, ecologists and agriculturists developed an increasingly sophisticated understanding of the value of biological diversity, specifically the resilience and adaptability it brings to ecosystems. In the twenty-first century, the ecosystem model has been applied to human systems, particularly to understanding how organizations are structured and how they operate. Twenty-first century organizations are challenged by diversity in many arenas. Demographic changes in workforce composition and customer populations, combined with globalized markets and international competition are increasing the amount of diversity organizations must manage, both internally and externally. Many diversity specialists and business leaders argue that businesses and organizations interested in surviving and thriving in the twenty-first century need to take competitive advantage of a diverse workplace (Soutar, 2004; Yang, 2005). But to do so successfully, leaders and human resources (HR) managers must redefine management and leadership (Jones, 1989). Just as mono-cropping destroys biological diversity, and, in extreme cases, such as the Irish potato famine--human as well as natural ecosystems (Keohane, n.d.), so does mono-managing similarly destroy diversity within organizations. Leaders wanting to build strong, diverse organizations will not be successful if they rely on one approach or solution. Single-threaded diversity solutions, such as focusing only on recruitment or single-approach management techniques, such as requiring every employee to take diversity training, do not create lasting change (Kossek & Lobel, 1996; McMahon, 2006; Thomas, 1990). Bringing about the changes needed to build and sustain diversity requires commitment, strategy, communication, and concrete changes in organizational structure and processes. How, then, can managers and leaders develop diverse organizations and ensure that they are managed to take optimum advantage of diversity? What role

Genetic diversity in a crop metapopulation

NARCIS (Netherlands)

Heerwaarden, van J.; Eeuwijk, van F.A.; Ross-Ibarra, J.

2010-01-01

The need to protect crop genetic resources has sparked a growing interest in the genetic diversity maintained in traditional farming systems worldwide. Although traditional seed management has been proposed as an important determinant of genetic diversity and structure in crops, no models exist that

Does Labour Diversity affect Firm Productivity?

DEFF Research Database (Denmark)

Parrotta, Pierpaolo; Pozzoli, Dario; Pytlikova, Mariola

Using a matched employer-employee dataset, we analyze how workforce diversity in cultural background, education and demographic characteristics affects productivity of firms in Denmark. Implementing a structural estimation of the firms' production function (Ackerberg et al., 2006) we find...... diverse workforce, seem to outweigh the positive effects coming from creativity and knowledge spillovers....... that labor diversity in education significantly enhances a firm's value added. Conversely, diversity in ethnicity and demographics induces negative effects on firm productivity. Hence, the negative effects, coming from communication and integration costs connected to a more culturally and demographically...

Huge increase in gas phase nanoparticle generation by pulsed direct current sputtering in a reactive gas admixture

Science.gov (United States)

Polonskyi, Oleksandr; Peter, Tilo; Mohammad Ahadi, Amir; Hinz, Alexander; Strunskus, Thomas; Zaporojtchenko, Vladimir; Biederman, Hynek; Faupel, Franz

2013-07-01

Using reactive DC sputtering in a gas aggregation cluster source, we show that pulsed discharge gives rise to a huge increase in deposition rate of nanoparticles by more than one order of magnitude compared to continuous operation. We suggest that this effect is caused by an equilibrium between slight target oxidation (during "time-off") and subsequent sputtering of Ti oxides (sub-oxides) at "time-on" with high power impulse.

Diverse Cd(II) compounds based on N-benzoyl-L-glutamic acid and N-donor ligands: Structures and photoluminescent properties

Energy Technology Data Exchange (ETDEWEB)

Ma, Ning; Guo, Wei-Ying; Song, Hui-Hua, E-mail: songhuihua@mail.hebtu.edu.cn; Yu, Hai-Tao, E-mail: haitaoyu@mail.hebtu.edu.cn

2016-01-15

Five new Cd(II) coordination polymers with N-benzoyl-L-glutamic acid (H{sub 2}bzgluO) and different N-donor ligands, [Cd(bzgluO)(2,2′-bipy)(H{sub 2}O)]{sub n} (1), [Cd(bzgluO)(2,4′-bipy){sub 2}(H{sub 2}O)·3H{sub 2}O]{sub n} (2), [Cd(bzgluO)(phen)·H{sub 2}O]{sub n} (3), [Cd(bzgluO)(4,4′-bipy)(H{sub 2}O)]{sub n} (4), [Cd(bzgluO)(bpp)(H{sub 2}O)·2H{sub 2}O]{sub n} (5) were synthesized (2,2′-bipy=2,2′-bipyridine, 2,4′-bipy=2,4′-bipyridine, phen=1,10-phenanthroline, 4,4′-bipy=4,4′-bipyridine, bpp=1,3-di(4-pyridyl)propane). Compounds 1–2 exhibit a 1D single-chain structure. Compound 1 generates a 2D supramolecular structure via π–π stacking and hydrogen bonding, 3D architecture of compound 2 is formed by hydrogen bonding. Compound 3 features a 1D double-chain structure, which are linked by π–π interactions into a 2D supramolecular layer. Compounds 4-5 display a 2D network structure. Neighboring layers of 4 are extended into a 3D supramolecular architecture through hydrogen bonding. The structural diversity of these compounds is attributed to the effect of ancillary N-donor ligands and coordination modes of H{sub 2}bzgluO. Luminescent properties of 1–5 were studied at room temperature. Circular dichroism of compounds 1, 2 and 5 were investigated. - Graphical abstract: Five new Cd(II) metal coordination compounds with H{sub 2}bzgluO and different N-donor ligands were synthesized and characterized. Compounds 1, 2 and 3 present 1D structures, compounds 4 and 5 display 2D networks. Results indicate that auxiliary ligands and coordination modes of H{sub 2}bzgluO play an important role in governing the formation of final frameworks, and the hydrogen-bonding and π–π stacking interactions contribute the formation of the diverse supramolecular architectures. Furthermore, the different crystal structures influence the emission spectra significantly. - Highlights: • It is rarely reported that complexes prepared with N-benzoyl-L-glutamic acid

Peptide folding in non-aqueous environments investigated with molecular dynamics simulations : possibilities and limitations

NARCIS (Netherlands)

Soto Becerra, Patricia

2004-01-01

Most of the fundamental biological tasks within living cells are performed by protein molecules. Although all natural proteins are built essentially from the same set of 20 amino acids, they exhibit a huge diversity of three-dimensional structure and an even greater range of function. ... Zie:

Amazing structure of respirasome: unveiling the secrets of cell respiration.

Science.gov (United States)

Guo, Runyu; Gu, Jinke; Wu, Meng; Yang, Maojun

2016-12-01

Respirasome, a huge molecular machine that carries out cellular respiration, has gained growing attention since its discovery, because respiration is the most indispensable biological process in almost all living creatures. The concept of respirasome has renewed our understanding of the respiratory chain organization, and most recently, the structure of respirasome solved by Yang's group from Tsinghua University (Gu et al. Nature 237(7622):639-643, 2016) firstly presented the detailed interactions within this huge molecular machine, and provided important information for drug design and screening. However, the study of cellular respiration went through a long history. Here, we briefly showed the detoured history of respiratory chain investigation, and then described the amazing structure of respirasome.

How does pedogenesis drive plant diversity?

Science.gov (United States)

Laliberté, Etienne; Grace, James B.; Huston, Michael A.; Lambers, Hans; Teste, François P.; Turner, Benjamin L.; Wardle, David A.

2013-01-01

Some of the most species-rich plant communities occur on ancient, strongly weathered soils, whereas those on recently developed soils tend to be less diverse. Mechanisms underlying this well-known pattern, however, remain unresolved. Here, we present a conceptual model describing alternative mechanisms by which pedogenesis (the process of soil formation) might drive plant diversity. We suggest that long-term soil chronosequences offer great, yet largely untapped, potential as 'natural experiments' to determine edaphic controls over plant diversity. Finally, we discuss how our conceptual model can be evaluated quantitatively using structural equation modeling to advance multivariate theories about the determinants of local plant diversity. This should help us to understand broader-scale diversity patterns, such as the latitudinal gradient of plant diversity.

Comparison of SSR and SNP markers in estimation of genetic diversity and population structure of Indian rice varieties.

Science.gov (United States)

Singh, Nivedita; Choudhury, Debjani Roy; Singh, Amit Kumar; Kumar, Sundeep; Srinivasan, Kalyani; Tyagi, R K; Singh, N K; Singh, Rakesh

2013-01-01

Simple sequence repeat (SSR) and Single Nucleotide Polymorphic (SNP), the two most robust markers for identifying rice varieties were compared for assessment of genetic diversity and population structure. Total 375 varieties of rice from various regions of India archived at the Indian National GeneBank, NBPGR, New Delhi, were analyzed using thirty six genetic markers, each of hypervariable SSR (HvSSR) and SNP which were distributed across 12 rice chromosomes. A total of 80 alleles were amplified with the SSR markers with an average of 2.22 alleles per locus whereas, 72 alleles were amplified with SNP markers. Polymorphic information content (PIC) values for HvSSR ranged from 0.04 to 0.5 with an average of 0.25. In the case of SNP markers, PIC values ranged from 0.03 to 0.37 with an average of 0.23. Genetic relatedness among the varieties was studied; utilizing an unrooted tree all the genotypes were grouped into three major clusters with both SSR and SNP markers. Analysis of molecular variance (AMOVA) indicated that maximum diversity was partitioned between and within individual level but not between populations. Principal coordinate analysis (PCoA) with SSR markers showed that genotypes were uniformly distributed across the two axes with 13.33% of cumulative variation whereas, in case of SNP markers varieties were grouped into three broad groups across two axes with 45.20% of cumulative variation. Population structure were tested using K values from 1 to 20, but there was no clear population structure, therefore Ln(PD) derived Δk was plotted against the K to determine the number of populations. In case of SSR maximum Δk was at K=5 whereas, in case of SNP maximum Δk was found at K=15, suggesting that resolution of population was higher with SNP markers, but SSR were more efficient for diversity analysis.

Analysis of the Genetic Diversity and Population Structure of Austrian and Belgian Wheat Germplasm within a Regional Context Based on DArT Markers

Directory of Open Access Journals (Sweden)

Mohamed A. El-Esawi

2018-01-01

Full Text Available Analysis of crop genetic diversity and structure provides valuable information needed to broaden the narrow genetic base as well as to enhance the breeding and conservation strategies of crops. In this study, 95 Austrian and Belgian wheat cultivars maintained at the Centre for Genetic Resources (CGN in the Netherlands were characterised using 1052 diversity array technology (DArT markers to evaluate their genetic diversity, relationships and population structure. The rarefacted allelic richness recorded in the Austrian and Belgian breeding pools (A25 = 1.396 and 1.341, respectively indicated that the Austrian germplasm contained a higher genetic diversity than the Belgian pool. The expected heterozygosity (HE values of the Austrian and Belgian pools were 0.411 and 0.375, respectively. Moreover, the values of the polymorphic information content (PIC of the Austrian and Belgian pools were 0.337 and 0.298, respectively. Neighbour-joining tree divided each of the Austrian and Belgian germplasm pools into two genetically distinct groups. The structure analyses of the Austrian and Belgian pools were in a complete concordance with their neighbour-joining trees. Furthermore, the 95 cultivars were compared to 618 wheat genotypes from nine European countries based on a total of 141 common DArT markers in order to place the Austrian and Belgian wheat germplasm in a wider European context. The rarefacted allelic richness (A10 varied from 1.224 (Denmark to 1.397 (Austria. Cluster and principal coordinates (PCoA analyses divided the wheat genotypes of the nine European countries into two main clusters. The first cluster comprised the Northern and Western European wheat genotypes, whereas the second included the Central European cultivars. The structure analysis of the 618 European wheat genotypes was in a complete concordance with the results of cluster and PCoA analyses. Interestingly, a highly significant difference was recorded between regions (26.53%. In

Soil microbial community structure in diverse land use systems:A comparative study using Biolog,DGGE,and PLFA analyses

Institute of Scientific and Technical Information of China (English)

XUE Dong; YAO Huai-Ying; GE De-Yong; HUANG Chang-Yong

2008-01-01

Biolog,16S rRNA gene denaturing gradient gel electrophoresis (DGGE),and phospholipid fatty acid (PLFA) analyses were used to assess soil microbial community characteristics in a chronosequence of tea garden systems (8-,50-,and 90year-old tea gardens),an adjacent wasteland,and a 90-year-old forest.Biolog analysis showed that the average well color development (AWCD) of all carbon sources and the functional diversity based on the Shannon index decreased (P＜0.05)in the following order:wasteland＞forest＞tea garden.For the DGGE analysis,the genetic diversity based on the Shannon index was significantly lower in the tea garden soils than in the wasteland.However,compared to the 90-year-old forest,the tea garden soils showed significantly higher genetic diversity.PLFA analysis showed that the ratio of Gram positive bacteria to Gram negative bacteria was significantly higher in the tea garden soils than in the wasteland,and the highest value was found in the 90-year-old forest.Both the fungal PLFA and the ratio of fungi to bacteria were significantly higher in the three tea garden soils than in the wasteland and forest,indicating that fungal PLFA was significantly affected by land-use change.Based on cluster analysis of the soil microbial community structure,all three analytical methods showed that land-use change had a greater effect on soil microbial community structure than tea garden age.

Mercury alters the bacterial community structure and diversity in soil even at concentrations lower than the guideline values.

Science.gov (United States)

Mahbub, Khandaker Rayhan; Subashchandrabose, Suresh Ramraj; Krishnan, Kannan; Naidu, Ravi; Megharaj, Mallavarapu

2017-03-01

This study evaluated the effect of inorganic mercury (Hg) on bacterial community and diversity in different soils. Three soils-neutral, alkaline and acidic-were spiked with six different concentrations of Hg ranging from 0 to 200 mg kg -1 and aged for 90 days. At the end of the ageing period, 18 samples from three different soils were investigated for bacterial community structure and soil physicochemical properties. Illumina MiSeq-based 16s ribosomal RNA (rRNA) amplicon sequencing revealed the alteration in the bacterial community between un-spiked control soils and Hg-spiked soils. Among the bacterial groups, Actinobacteria (22.65%) were the most abundant phyla in all samples followed by Proteobacteria (21.95%), Bacteroidetes (4.15%), Firmicutes (2.9%) and Acidobacteria (2.04%). However, the largest group showing increased abundance with higher Hg doses was the unclassified group (45.86%), followed by Proteobacteria. Mercury had a considerable negative impact on key soil functional bacteria such as ammonium oxidizers and nitrifiers. Canonical correspondence analysis (CCA) indicated that among the measured soil properties, Hg had a major influence on bacterial community structure. Furthermore, nonlinear regression analysis confirmed that Hg significantly decreased soil bacterial alpha diversity in lower organic carbon containing neutral and alkaline soils, whereas in acidic soil with higher organic carbon there was no significant correlation. EC 20 values obtained by a nonlinear regression analysis indicated that Hg significantly decreased soil bacterial diversity in concentrations lower than several guideline values.

Enzyme structure, enzyme function and allozyme diversity in ...

African Journals Online (AJOL)

In estimates of population genetic diversity based on allozyme heterozygosity, some enzymes are regularly more variable than others. Evolutionary theory suggests that functionally less important molecules, or parts of molecules, evolve more rapidly than more important ones; the latter enzymes should then theoretically be ...

Host population genetic structure and zooxanthellae diversity of two reef-building coral species along the Florida Reef Tract and wider Caribbean

Science.gov (United States)

Baums, I. B.; Johnson, M. E.; Devlin-Durante, M. K.; Miller, M. W.

2010-12-01

In preparation for a large-scale coral restoration project, we surveyed host population genetic structure and symbiont diversity of two reef-building corals in four reef zones along the Florida reef tract (FRT). There was no evidence for coral population subdivision along the FRT in Acropora cervicornis or Montastraea faveolata based on microsatellite markers. However, in A. cervicornis, significant genetic differentiation was apparent when extending the analysis to broader scales (Caribbean). Clade diversity of the zooxanthellae differed along the FRT. A. cervicornis harbored mostly clade A with clade D zooxanthellae being prominent in colonies growing inshore and in the mid-channel zones that experience greater temperature fluctuations and receive significant nutrient and sediment input. M. faveolata harbored a more diverse array of symbionts, and variation in symbiont diversity among four habitat zones was more subtle but still significant. Implications of these results are discussed for ongoing restoration and conservation work.

Genetic diversity and trait genomic prediction in a pea diversity panel.

Science.gov (United States)

Burstin, Judith; Salloignon, Pauline; Chabert-Martinello, Marianne; Magnin-Robert, Jean-Bernard; Siol, Mathieu; Jacquin, Françoise; Chauveau, Aurélie; Pont, Caroline; Aubert, Grégoire; Delaitre, Catherine; Truntzer, Caroline; Duc, Gérard

2015-02-21

Pea (Pisum sativum L.), a major pulse crop grown for its protein-rich seeds, is an important component of agroecological cropping systems in diverse regions of the world. New breeding challenges imposed by global climate change and new regulations urge pea breeders to undertake more efficient methods of selection and better take advantage of the large genetic diversity present in the Pisum sativum genepool. Diversity studies conducted so far in pea used Simple Sequence Repeat (SSR) and Retrotransposon Based Insertion Polymorphism (RBIP) markers. Recently, SNP marker panels have been developed that will be useful for genetic diversity assessment and marker-assisted selection. A collection of diverse pea accessions, including landraces and cultivars of garden, field or fodder peas as well as wild peas was characterised at the molecular level using newly developed SNP markers, as well as SSR markers and RBIP markers. The three types of markers were used to describe the structure of the collection and revealed different pictures of the genetic diversity among the collection. SSR showed the fastest rate of evolution and RBIP the slowest rate of evolution, pointing to their contrasted mode of evolution. SNP markers were then used to predict phenotypes -the date of flowering (BegFlo), the number of seeds per plant (Nseed) and thousand seed weight (TSW)- that were recorded for the collection. Different statistical methods were tested including the LASSO (Least Absolute Shrinkage ans Selection Operator), PLS (Partial Least Squares), SPLS (Sparse Partial Least Squares), Bayes A, Bayes B and GBLUP (Genomic Best Linear Unbiased Prediction) methods and the structure of the collection was taken into account in the prediction. Despite a limited number of 331 markers used for prediction, TSW was reliably predicted. The development of marker assisted selection has not reached its full potential in pea until now. This paper shows that the high-throughput SNP arrays that are being

Scaffold Diversity from N-Acyliminium Ions

DEFF Research Database (Denmark)

Wu, Peng; Nielsen, Thomas E

2017-01-01

N-Acyliminium ions are powerful reactive species for the formation of carbon-carbon and carbon-heteroatom bonds. Strategies relying on intramolecular reactions of N-acyliminium intermediates, also referred to as N-acyliminium ion cyclization reactions, have been employed for the construction...... of structurally diverse scaffolds, ranging from simple bicyclic skeletons to complex polycyclic systems and natural-product-like compounds. This review aims to provide an overview of cyclization reactions of N-acyliminium ions derived from various precursors for the assembly of structurally diverse scaffolds...

Huge thermal conductivity enhancement in boron nitride – ethylene glycol nanofluids

International Nuclear Information System (INIS)

Żyła, Gaweł; Fal, Jacek; Traciak, Julian; Gizowska, Magdalena; Perkowski, Krzysztof

2016-01-01

Paper presents the results of experimental studies on thermophysical properties of boron nitride (BN) plate-like shaped particles in ethylene glycol (EG). Essentially, the studies were focused on the thermal conductivity of suspensions of these particles. Nanofluids were obtained with two-step method (by dispersing BN particles in ethylene glycol) and its’ thermal conductivity was analyzed at various mass concentrations, up to 20 wt. %. Thermal conductivity was measured in temperature range from 293.15 K to 338.15 K with 15 K step. The measurements of thermal conductivity of nanofluids were performed in the system based on a device using the transient line heat source method. Studies have shown that nanofluids’ thermal conductivity increases with increasing fraction of nanoparticles. The results of studies also presented that the thermal conductivity of nanofluids changes very slightly with the increase of temperature. - Highlights: • Huge thermal conductivity enhancement in BN-EG nanofluid was reported. • Thermal conductivity increase very slightly with increasing of the temperature. • Thermal conductivity increase linearly with volume concentration of particles.

Huge thermal conductivity enhancement in boron nitride – ethylene glycol nanofluids

Energy Technology Data Exchange (ETDEWEB)

Żyła, Gaweł, E-mail: gzyla@prz.edu.pl [Department of Physics and Medical Engineering, Rzeszow University of Technology, Rzeszow, 35-905 (Poland); Fal, Jacek; Traciak, Julian [Department of Physics and Medical Engineering, Rzeszow University of Technology, Rzeszow, 35-905 (Poland); Gizowska, Magdalena; Perkowski, Krzysztof [Department of Nanotechnology, Institute of Ceramics and Building Materials, Warsaw, 02-676 (Poland)

2016-09-01

Paper presents the results of experimental studies on thermophysical properties of boron nitride (BN) plate-like shaped particles in ethylene glycol (EG). Essentially, the studies were focused on the thermal conductivity of suspensions of these particles. Nanofluids were obtained with two-step method (by dispersing BN particles in ethylene glycol) and its’ thermal conductivity was analyzed at various mass concentrations, up to 20 wt. %. Thermal conductivity was measured in temperature range from 293.15 K to 338.15 K with 15 K step. The measurements of thermal conductivity of nanofluids were performed in the system based on a device using the transient line heat source method. Studies have shown that nanofluids’ thermal conductivity increases with increasing fraction of nanoparticles. The results of studies also presented that the thermal conductivity of nanofluids changes very slightly with the increase of temperature. - Highlights: • Huge thermal conductivity enhancement in BN-EG nanofluid was reported. • Thermal conductivity increase very slightly with increasing of the temperature. • Thermal conductivity increase linearly with volume concentration of particles.

Structural characterization of alkaline hydrogen peroxide pretreated grasses exhibiting diverse lignin phenotypes

Science.gov (United States)

2012-01-01

Background For cellulosic biofuels processes, suitable characterization of the lignin remaining within the cell wall and correlation of quantified properties of lignin to cell wall polysaccharide enzymatic deconstruction is underrepresented in the literature. This is particularly true for grasses which represent a number of promising bioenergy feedstocks where quantification of grass lignins is particularly problematic due to the high fraction of p-hydroxycinnamates. The main focus of this work is to use grasses with a diverse range of lignin properties, and applying multiple lignin characterization platforms, attempt to correlate the differences in these lignin properties to the susceptibility to alkaline hydrogen peroxide (AHP) pretreatment and subsequent enzymatic deconstruction. Results We were able to determine that the enzymatic hydrolysis of cellulose to to glucose (i.e. digestibility) of four grasses with relatively diverse lignin phenotypes could be correlated to total lignin content and the content of p-hydroxycinnamates, while S/G ratios did not appear to contribute to the enzymatic digestibility or delignification. The lignins of the brown midrib corn stovers tested were significantly more condensed than a typical commercial corn stover and a significant finding was that pretreatment with alkaline hydrogen peroxide increases the fraction of lignins involved in condensed linkages from 88–95% to ~99% for all the corn stovers tested, which is much more than has been reported in the literature for other pretreatments. This indicates significant scission of β-O-4 bonds by pretreatment and/or induction of lignin condensation reactions. The S/G ratios in grasses determined by analytical pyrolysis are significantly lower than values obtained using either thioacidolysis or 2DHSQC NMR due to presumed interference by ferulates. Conclusions It was found that grass cell wall polysaccharide hydrolysis by cellulolytic enzymes for grasses exhibiting a diversity of

Structural characterization of alkaline hydrogen peroxide pretreated grasses exhibiting diverse lignin phenotypes

Directory of Open Access Journals (Sweden)

Li Muyang

2012-06-01

exhibiting a diversity of lignin structures and compositions could be linked to quantifiable changes in the composition of the cell wall and properties of the lignin including apparent content of the p-hydroxycinnamates while the limitations of S/G estimation in grasses is highlighted.

Tree species diversity promotes aboveground carbon storage through functional diversity and functional dominance.

Science.gov (United States)

Mensah, Sylvanus; Veldtman, Ruan; Assogbadjo, Achille E; Glèlè Kakaï, Romain; Seifert, Thomas

2016-10-01

The relationship between biodiversity and ecosystem function has increasingly been debated as the cornerstone of the processes behind ecosystem services delivery. Experimental and natural field-based studies have come up with nonconsistent patterns of biodiversity-ecosystem function, supporting either niche complementarity or selection effects hypothesis. Here, we used aboveground carbon (AGC) storage as proxy for ecosystem function in a South African mistbelt forest, and analyzed its relationship with species diversity, through functional diversity and functional dominance. We hypothesized that (1) diversity influences AGC through functional diversity and functional dominance effects; and (2) effects of diversity on AGC would be greater for functional dominance than for functional diversity. Community weight mean (CWM) of functional traits (wood density, specific leaf area, and maximum plant height) were calculated to assess functional dominance (selection effects). As for functional diversity (complementarity effects), multitrait functional diversity indices were computed. The first hypothesis was tested using structural equation modeling. For the second hypothesis, effects of environmental variables such as slope and altitude were tested first, and separate linear mixed-effects models were fitted afterward for functional diversity, functional dominance, and both. Results showed that AGC varied significantly along the slope gradient, with lower values at steeper sites. Species diversity (richness) had positive relationship with AGC, even when slope effects were considered. As predicted, diversity effects on AGC were mediated through functional diversity and functional dominance, suggesting that both the niche complementarity and the selection effects are not exclusively affecting carbon storage. However, the effects were greater for functional diversity than for functional dominance. Furthermore, functional dominance effects were strongly transmitted by CWM of

Intraspecies genomic diversity and natural population structure of the meat-borne lactic acid bacterium Lactobacillus sakei.

Science.gov (United States)

Chaillou, Stéphane; Daty, Marie; Baraige, Fabienne; Dudez, Anne-Marie; Anglade, Patricia; Jones, Rhys; Alpert, Carl-Alfred; Champomier-Vergès, Marie-Christine; Zagorec, Monique

2009-02-01

Lactobacillus sakei is a food-borne bacterium naturally found in meat and fish products. A study was performed to examine the intraspecies diversity among 73 isolates sourced from laboratory collections in several different countries. Pulsed-field gel electrophoresis analysis demonstrated a 25% variation in genome size between isolates, ranging from 1,815 kb to 2,310 kb. The relatedness between isolates was then determined using a PCR-based method that detects the possession of 60 chromosomal genes belonging to the flexible gene pool. Ten different strain clusters were identified that had noticeable differences in their average genome size reflecting the natural population structure. The results show that many different genotypes may be isolated from similar types of meat products, suggesting a complex ecological habitat in which intraspecies diversity may be required for successful adaptation. Finally, proteomic analysis revealed a slight difference between the migration patterns of highly abundant GapA isoforms of the two prevailing L. sakei subspecies (sakei and carnosus). This analysis was used to affiliate the genotypic clusters with the corresponding subspecies. These findings reveal for the first time the extent of intraspecies genomic diversity in L. sakei. Consequently, identification of molecular subtypes may in the future prove valuable for a better understanding of microbial ecosystems in food products.

Genetic Diversity and Population Structure of Collard Landraces and their Relationship to Other Brassica oleracea Crops

Directory of Open Access Journals (Sweden)

Sandra E. Pelc

2015-11-01

Full Text Available Landraces have the potential to provide a reservoir of genetic diversity for crop improvement to combat the genetic erosion of the food supply. A landrace collection of the vitamin-rich specialty crop collard ( L. var. was genetically characterized to assess its potential for improving the diverse crop varieties of . We used the Illumina 60K SNP BeadChip array with 52,157 single nucleotide polymorphisms (SNPs to (i clarify the relationship of collard to the most economically important crop types, (ii evaluate genetic diversity and population structure of 75 collard landraces, and (iii assess the potential of the collection for genome-wide association studies (GWAS through characterization of genomic patterns of linkage disequilibrium. Confirming the collection as a valuable genetic resource, the collard landraces had twice the polymorphic markers (11,322 SNPs and 10 times the variety-specific alleles (521 alleles of the remaining crop types examined in this study. On average, linkage disequilibrium decayed to background levels within 600 kilobase (kb, allowing for sufficient coverage of the genome for GWAS using the physical positions of the 8273 SNPs polymorphic among the landraces. Although other relationships varied, the previous placement of collard with the cabbage family was confirmed through phylogenetic analysis and principal coordinates analysis (PCoA.

Species Diversity Enhances Predator Growth Rates

International Nuclear Information System (INIS)

Olson, M.H.; Jacobs, R.P.; O'Donnell, E.B.

2007-01-01

Predators can be important top-down regulators of community structure and are known to have both positive and negative effects on species diversity. However, little is known about the reciprocal effects of species diversity on predators. Across a set of 80 lakes in Connecticut, USA, we found a strong positive correlation between prey species diversity (using the Shannon-Weiner Diversity Index) and growth rates of largemouth bass (Micropterus salmoides). This correlation was strongest for small predators and decreased with body size. Although the underlying mechanisms are not known, the correlation is not driven by total fish abundance, predator abundance, or productivity.

Using Simpson’s diversity index to examine multidimensional models of diversity in health professions education

Science.gov (United States)

McLaughlin, Gerald W.; McLaughlin, Josetta S.; White, Carla Y.

2016-01-01

Objectives This study explored new models of diversity for health professions education that incorporate multiple attributes and examined differences in diversity based on urbanicity, geographic region, and institutional structure. Methods Simpson’s Diversity Index was used to develop race, gender, and interprofessional diversity indices for health professions schools in the United States (N = 318). Sullivan’s extension was used to develop a composite diversity index that incorporated multiple individual attributes for each school. Pearson’s r was used to investigate correlations between continuous variables. ANOVA and independent t-tests were used to compare groups based on urbanicity, geographic region, and Basic Carnegie Classification. Results Mean (SD) for race, gender, and interprofessional  diversity indices were 0.36(0.17), 0.45(0.07), and 0.22(0.27) respectively. All correlations between the three indices were weak. The composite diversity index for this sample was 0.34(0.13). Significant differences in diversity were found between institutions based on urbanicity, Basic Carnegie Classification, and geographic region. Conclusions Multidimensional models provide support for expanding measures of diversity to include multiple characteristics and attributes. The approach demonstrated in this study enables institutions to complement and extend traditional measures of diversity as a means of providing evidence for decision-making and progress towards institutional initiatives. PMID:26724917

Typological diversity of tall buildings and complexes in relation to their functional structure

Science.gov (United States)

Generalov, Viktor P.; Generalova, Elena M.; Kalinkina, Nadezhda A.; Zhdanova, Irina V.

2018-03-01

The paper focuses on peculiarities of tall buildings and complexes, their typology and its formation in relation to their functional structure. The research is based on the analysis of tall buildings and complexes and identifies the following main functional elements of their formation: residential, administrative (office), hotel elements. The paper also considers the following services as «disseminated» in the space-planning structure: shops, medicine, entertainment, kids and sports facilities, etc., their location in the structure of the total bulk of the building and their impact on typological diversity. Research results include suggestions to add such concepts as «single-function tall buildings» and «mixed-use tall buildings and complexes» into the classification of tall buildings. In addition, if a single-function building or complex performs serving functions, it is proposed to add such concepts as «a residential tall building (complex) with provision of services», «an administrative (public) tall building (complex) with provision of services» into the classification of tall buildings. For mixed-use buildings and complexes the following terms are suggested: «a mixed-use tall building with provision of services», «a mixed-use tall complex with provision of services».

Genetic diversity in tef [Eragrostis tef (Zucc. Trotter

Directory of Open Access Journals (Sweden)

Kebebew eAssefa

2015-03-01

Full Text Available Tef [Eragrostis tef (Zucc. Trotter] is a cereal crop resilient to adverse climatic and soil conditions, and possessing desirable storage properties. Although tef provides high quality food and grows under marginal conditions unsuitable for other cereals, it is considered to be an orphan crop because it has benefited little from genetic improvement. Hence, unlike other cereals such as maize and wheat, the productivity of tef is extremely low. In spite of the low productivity, tef is widely cultivated by over six million small-scale farmers in Ethiopia where it is annually grown on more than three million hectares of land, accounting for over 30% of the total cereal acreage. Tef, a tetraploid with 40 chromosomes (2n=4x=40, belongs to the Family Poaceae and, together with finger millet (Eleusine coracana Gaertn, to the Subfamily Chloridoideae. It was believed to have originated in Ethiopia. There are about 350 Eragrostis species of which E. tef is the only species cultivated for human consumption. At the present time, the gene bank in Ethiopia holds over five thousand tef accessions collected from geographical regions diverse in terms of climate and elevation. These germplasm accessions appear to have huge variability with regard to key agronomic and nutritional traits. In order to properly utilize the variability in developing new tef cultivars, various techniques have been implemented to catalog the extent and unravel the patterns of genetic diversity. In this review, we show some recent initiatives investigating the diversity of tef using genomics, transcriptomics and proteomics and discuss the prospect of these efforts in providing molecular resources that can aid modern tef breeding.

Structural barriers to HIV prevention among men who have sex with men (MSM) in Vietnam: Diversity, stigma, and healthcare access.

Science.gov (United States)

Philbin, Morgan M; Hirsch, Jennifer S; Wilson, Patrick A; Ly, An Thanh; Giang, Le Minh; Parker, Richard G

2018-01-01

Men who have sex with men (MSM) in Vietnam experience disproportionate rates of HIV infection. To advance understanding of how structural barriers may shape their engagement with HIV prevention services, we draw on 32 in-depth interviews and four focus groups (n = 31) conducted with MSM in Hanoi between October 2015- March 2016. Three primary factors emerged: (1) Diversity, both in relation to identity and income; Vietnamese MSM described themselves as segregated into Bóng kín (hidden, often heterosexually-identified MSM) and Bóng lộ ('out,' transgender, or effeminate MSM). Lower-income, 'hidden' MSM from rural areas were reluctant to access MSM-targeted services; (2) Stigma: MSM reported being stigmatized by the healthcare system, family, and other MSM; and (3) Healthcare access: this was limited due to economic barriers and lack of MSM-friendly services. Our research suggests the need for multiple strategies to reach diverse types of MSM as well as to address barriers in access to health services such as stigma and costs. While a great deal has been written about the diversity of MSM in relation to gender performance and sexual identities, our research points to the substantial structural-level barriers that must be addressed in order to achieve meaningful and effective HIV prevention for MSM worldwide.

Genetic Diversity and Population Structure of Mesoamerican Jaguars (Panthera onca): Implications for Conservation and Management.

Science.gov (United States)

Wultsch, Claudia; Caragiulo, Anthony; Dias-Freedman, Isabela; Quigley, Howard; Rabinowitz, Salisa; Amato, George

2016-01-01

Mesoamerican jaguars (Panthera onca) have been extirpated from over 77% of their historic range, inhabiting fragmented landscapes at potentially reduced population sizes. Maintaining and restoring genetic diversity and connectivity across human-altered landscapes has become a major conservation priority; nonetheless large-scale genetic monitoring of natural populations is rare. This is the first regional conservation genetic study of jaguars to primarily use fecal samples collected in the wild across five Mesoamerican countries: Belize, Costa Rica, Guatemala, Honduras, and Mexico. We genotyped 445 jaguar fecal samples and examined patterns of genetic diversity and connectivity among 115 individual jaguars using data from 12 microsatellite loci. Overall, moderate levels of genetic variation were detected (NA = 4.50 ± 1.05, AR = 3.43 ± 0.22, HE = 0.59 ± 0.04), with Mexico having the lowest genetic diversity, followed by Honduras, Guatemala, Belize, and Costa Rica. Population-based gene flow measures (FST = 0.09 to 0.15, Dest = 0.09 to 0.21), principal component analysis, and Bayesian clustering applied in a hierarchical framework revealed significant genetic structure in Mesoamerican jaguars, roughly grouping individuals into four genetic clusters with varying levels of admixture. Gene flow was highest among Selva Maya jaguars (northern Guatemala and central Belize), whereas genetic differentiation among all other sampling sites was moderate. Genetic subdivision was most pronounced between Selva Maya and Honduran jaguars, suggesting limited jaguar movement between these close geographic regions and ultimately refuting the hypothesis of contemporary panmixia. To maintain a critical linkage for jaguars dispersing through the Mesoamerican landscape and ensure long-term viability of this near threatened species, we recommend continued management and maintenance of jaguar corridors. The baseline genetic data provided by this study underscores the importance of

Extra-zonal beech forests in Tuscany: structure, diversity and synecologic features

Directory of Open Access Journals (Sweden)

Viciani D

2011-07-01

Full Text Available The present paper focuses on the structural, synecological and floristic diversity features of beech-dominated forest communities in four major areas of the Antiapenninic Tyrrhenian system in Tuscany: Metalliferous hills, mountains to the south of Mt. Amiata, volcanic area of the upper Lente valley and Mt. Cetona. These are relict woodlands of Holo-Pleistocene origin with a special ecological and conservation value due to their extrazonal location in lowland submediterranean areas. Results show substantial among-area differences in structure, synecology and plant species composition, but in general a potential for coppices to reach the tall forest stage, as demonstrated by the old-growth stands of Pietraporciana and Sassoforte. Compared with montane Apenninic beechwoods, the relatively rich flora of the studied communities include thermophilous species with a southern Apennine-Balkan distribution, making their syntaxonomical position unclear. Closer affinities are found with the calcicolous Beech Forests of the association and with the silicicolous ones of the . Based on the Natura 2000 system, all the examined communities belong to the priority Habitat “Apennine beech forests with and ” (code: 9210*. Due their relict nature, these biotopes appear vulnerable to climate changes and to a production-oriented forest management. Criteria of naturalistic silviculture should instead promote the dynamic development of these communities towards tall forests and their natural regeneration.

Elective hemi transurethral resection of prostate: a safe and effective method of treating huge benign prostatic hyperplasia

International Nuclear Information System (INIS)

Abidi, S.S.; Feroz, I.; Aslam, M.; Fawad, A.

2012-01-01

To evaluate the safety and efficacy of elective hemi-resection of prostate in patients with huge gland, weighing more than 120 grams. Study Design: Multi centric, analytical comparative study. Place and Duration of Study: Department of Urology, Karachi Medical and Dental College, Abbasi Shaheed Hospital and Dr. Ziauddin Hospital, Karachi, from August 2006 to July 2009. Methodology: All benign cases were included in this study and divided into two groups. In group A, patients having huge prostate (> 120 grams) were placed and hemi TURP was performed. In group B, patients having 60 to 100 grams prostate were placed and conventional Blandy's TURP was performed. Results of both groups were compared in terms of duration of surgery, amount of tissue resected, operative bleeding, postoperative complications, duration of postoperative catheterization, re-admission and re-operations. Effectiveness of procedure was assessed by a simple questionnaire filled by the patients at first month, first year and second year. Patients satisfaction in terms of their ability to void, control urination, frequency, urgency, urge incontinence, haematuria, recurrent UTI, re-admission and re-operations were also assessed. Fisher exact test was applied to compare the safety and efficacy of variables. Results: In group A and B, average age range was 72 and 69 years, average weight of prostate was 148 and 70 grams, average duration of surgery was 102 and 50 minutes respectively. Average weight of resected tissue was 84 and 54 grams and haemoglobin loss was two grams and one gram respectively. Total hospital stay was 5 and 4 days. Total duration of indwelling Foley's catheter (postoperative) was 5 days and 2 days. Patient satisfaction in term of urine flow, urinary control, improvement in frequency and nocturia were comparable in both groups. UTI and re-admission was more in hemi resection group. At the end of 2 years follow-up, there is no statistical difference between the safety and efficacy

Animal social networks as substrate for cultural behavioural diversity.

Science.gov (United States)

Whitehead, Hal; Lusseau, David

2012-02-07

We used individual-based stochastic models to examine how social structure influences the diversity of socially learned behaviour within a non-human population. For continuous behavioural variables we modelled three forms of dyadic social learning, averaging the behavioural value of the two individuals, random transfer of information from one individual to the other, and directional transfer from the individual with highest behavioural value to the other. Learning had potential error. We also examined the transfer of categorical behaviour between individuals with random directionality and two forms of error, the adoption of a randomly chosen existing behavioural category or the innovation of a new type of behaviour. In populations without social structuring the diversity of culturally transmitted behaviour increased with learning error and population size. When the populations were structured socially either by making individuals members of permanent social units or by giving them overlapping ranges, behavioural diversity increased with network modularity under all scenarios, although the proportional increase varied considerably between continuous and categorical behaviour, with transmission mechanism, and population size. Although functions of the form e(c)¹(m)⁻(c)² + (c)³(Log(N)) predicted the mean increase in diversity with modularity (m) and population size (N), behavioural diversity could be highly unpredictable both between simulations with the same set of parameters, and within runs. Errors in social learning and social structuring generally promote behavioural diversity. Consequently, social learning may be considered to produce culture in populations whose social structure is sufficiently modular. Copyright © 2011 Elsevier Ltd. All rights reserved.