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Sample records for individual dominant species

  1. Urban Bird Feeders Dominated by a Few Species and Individuals

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    Josie A. Galbraith

    2017-08-01

    Full Text Available The practice of garden bird feeding is a global phenomenon, involving millions of people and vast quantities of food annually. Many people engage in the practice of feeding assuming that birds gain some benefit from the food they provide, yet recent studies have revealed the potential for detrimental impacts as well. However, there is still a paucity of information on the impacts of feeding, including the ubiquity of these impacts among and within feeder-visiting species. Consistency in feeder use among birds is likely an important determinant of this. Individual birds and species that make frequent use of feeders are more likely to experience both the benefits and detrimental impacts of supplementary food. We investigated patterns of feeder use by garden birds visiting experimental feeding stations in Auckland, New Zealand, with the specific aim of determining whether use of supplementary food was consistent or variable among individuals and species. We used camera traps as well as Radio Frequency Identification (RFID technology to examine intra- and interspecific feeder visitation patterns and to discern species associations. Eleven bird species were detected using feeding stations, however, two introduced species (house sparrow Passer domesticus and spotted dove Streptopelia chinensis dominated visitation events. These species were present at feeders most frequently, with the largest conspecific group sizes. Significant associations were detected among a number of species, suggesting interspecific interactions are important in determining feeder use. We also found within-species differences in feeder use for all focal species, with individual variation greatest in house sparrows. Furthermore, season had an important influence on most visitation parameters. The observed individual and species-specific differences in supplementary food resource use imply that the impacts of garden bird feeding are not universal. Crucially, particularly given

  2. The diet and consumption of dominant fish species in the upper Scheldt estuary, Belgium

    DEFF Research Database (Denmark)

    Maes, J.; De Brabandere, Loreto; Ollevier, F.

    2003-01-01

    Seasonal changes in the diet composition and trophic niche overlap were examined for the dominant members of the fish assemblage of the turbid low-salinity zone of the Scheldt estuary (Belgium). Samples of fish were taken in the cooling water of a power plant. Juveniles of eight species dominated...... of trophic niche overlap showed that, in general, niche overlap between individuals of the same species was significantly higher than overlap between individuals from different species, suggesting that the available food resources were partitioned. The total annual prey consumption by the dominant fish...

  3. Genetic sorting of subordinate species in grassland modulated by intraspecific variation in dominant species.

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    Danny J Gustafson

    Full Text Available Genetic variation in a single species can have predictable and heritable effects on associated communities and ecosystem processes, however little is known about how genetic variation of a dominant species affects plant community assembly. We characterized the genetic structure of a dominant grass (Sorghastrum nutans and two subordinate species (Chamaecrista fasciculata, Silphium integrifolium, during the third growing season in grassland communities established with genetically distinct (cultivated varieties or local ecotypes seed sources of the dominant grasses. There were genetic differences between subordinate species growing in the cultivar versus local ecotype communities, indicating that intraspecific genetic variation in the dominant grasses affected the genetic composition of subordinate species during community assembly. A positive association between genetic diversity of S. nutans, C. fasciculata, and S. integrifolium and species diversity established the role of an intraspecific biotic filter during community assembly. Our results show that intraspecific variation in dominant species can significantly modulate the genetic composition of subordinate species.

  4. No change in subordinate butterflyfish diets following removal of behaviourally dominant species

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    Blowes, Shane A.; Pratchett, Morgan S.; Connolly, Sean R.

    2017-03-01

    Direct interference interactions between species are often mediated by aggression and related to resource use. Interference interactions are frequently asymmetric, whereby one species wins the majority of interactions; however, the effect of this asymmetry on the diet of subordinate species has not received the same attention as the impact of interference on habitat use. Here we experimentally evaluated whether release from asymmetric interference led to increased use of a preferred dietary resource by subordinate species, using coral-feeding butterflyfishes as a model system. Following experimental removal of the behaviourally dominant species, we found no change in diet breadth or foraging on the preferred resource by subordinate species. Our results suggest that release from asymmetric interspecific interference does not necessarily result in changes to subordinate species' diets, at least not over the course of our study. Rather, consistently asymmetric interactions may contribute to behavioural conditioning of subordinate species, meaning that even in the absence of dominants, subordinate individuals maintain established feeding patterns. Additionally, our results suggest that antagonistic interactions between butterflyfishes may have contributed to niche partitioning and conservatism over evolutionary time scales.

  5. Individual species-area relationship of woody plant communities in a heterogeneous subtropical monsoon rainforest.

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    Tsai, Cheng-Han; Lin, Yi-Ching; Wiegand, Thorsten; Nakazawa, Takefumi; Su, Sheng-Hsin; Hsieh, Chih-Hao; Ding, Tzung-Su

    2015-01-01

    The spatial structure of species richness is often characterized by the species-area relationship (SAR). However, the SAR approach rarely considers the spatial variability of individual plants that arises from species interactions and species' habitat associations. Here, we explored how the interactions of individual plants of target species influence SAR patterns at a range of neighborhood distances. We analyzed the data of 113,988 woody plants of 110 species from the Fushan Forest Dynamics Plot (25 ha), northern Taiwan, which is a subtropical rainforest heavily influenced by typhoons. We classified 34 dominant species into 3 species types (i.e., accumulator, repeller, or no effect) by testing how the individual species-area relationship (i.e., statistics describing how neighborhood species richness changes around individuals) of target species departs (i.e., positively, negatively, or with no obvious trend) from a null model that accounts for habitat association. Deviation from the null model suggests that the net effect of species' interactions increases (accumulate) or decreases (repel) neighborhood species richness. We found that (i) accumulators were dominant at small interaction distances (30 m); (iii) repellers were rarely detected; and (iv) large-sized and abundant species tended to be accumulators. The findings suggest that positive species interactions have the potential to accumulate neighborhood species richness, particularly through size- and density-dependent mechanisms. We hypothesized that the frequently disturbed environment of this subtropical rainforest (e.g., typhoon-driven natural disturbances such as landslides, soil erosion, flooding, and windthrow) might create the spatial heterogeneity of species richness and promote positive species interactions.

  6. Changing drivers of species dominance during tropical forest succession

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    Lohbeck, M.W.M.; Poorter, L.; Martinez-Ramos, M.; Rodriguez-Valázquez, J.; Breugel, van M.; Bongers, F.

    2014-01-01

    1. Deterministic theories predict that local communities assemble from a regional species pool based on niche differences, thus by plant functional adaptations. We tested whether functional traits can also explain patterns in species dominance among the suite of co-occurring species. 2. We predicted

  7. Relationships between browsing damage and the species dominance by the highly food-attractive and less food-attractive trees

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    Petr Čermák

    2011-01-01

    Full Text Available The paper analyses data on the browsing damage to Acer pseudoplatanus, Carpinus betulus, Fraxinus excelsior, Quercus spp., Tilia cordata and Fagus sylvatica. Field research was carried out in the period 2007–2010 and analysed data came from 33 transects at 10 localities with the various abundance of game in the CR (everywhere Capreolus capreolus, on several plots also Cervus elaphus, Ovis musimon or Dama dama. Trees were monitored up to a height of 150 cm in natural regeneration under stands and in plantations and the occurrence was noted of new browsing damage. Differences between the percentage of damaged individuals of the given species of a food-attractive species (A. p., C. b., F. e. and the percentage of damaged individuals of all tree species on a transect as well as the proportion of these parameters correlate negatively with the given species dominance and thus, they appear to be suitable parameters for the analysis of relationships between the damage intensity and dominance. The higher the percentage proportions of highly food-attractive species and the lower the percentage of less-attractive species, the lower the relative intensity of damage to highly food-attractive species. At the same time, the higher the percentage proportion of highly food-attractive species and the lower the percentage of less-attractive species then the lower a difference between damage to less food-attractive species and all species.

  8. Epistasis modifies the dominance of loci causing hybrid male sterility in the Drosophila pseudoobscura species group.

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    Chang, Audrey S; Noor, Mohamed A F

    2010-01-01

    Speciation, the evolution of reproductive isolation between populations, serves as the driving force for generating biodiversity. Postzygotic barriers to gene flow, such as F(1) hybrid sterility and inviability, play important roles in the establishment and maintenance of biological species. F(1) hybrid incompatibilities in taxa that obey Haldane's rule, the observation that the heterogametic sex suffers greater hybrid fitness problems than the homogametic sex, are thought to often result from interactions between recessive-acting X-linked loci and dominant-acting autosomal loci. Because they play such prominent roles in producing hybrid incompatibilities, we examine the dominance and nature of epistasis between alleles derived from Drosophila persimilis that confer hybrid male sterility in the genetic background of its sister species, D. pseudoobscura bogotana. We show that epistasis elevates the apparent dominance of individually recessive-acting QTL such that they can contribute to F(1) hybrid sterility. These results have important implications for assumptions underlying theoretical models of hybrid incompatibilities and may offer a possible explanation for why, to date, identification of dominant-acting autosomal "speciation genes" has been challenging.

  9. Species dominance and equitability: patterns in Cenozoic foraminifera of eastern North America

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    Gibson, T.G.; Hill, E.E.

    1992-01-01

    Species dominance in benthonic foraminifera, represented by percent of the assemblage composed of the single most abundant species, shows little change in observed range of values from shallow into deep-marine waters in 1005 samples from the Gulf of Mexico, Atlantic, and Arctic margins of North America. This finding contrasts with the model that species dominance is highest in shallow-marine environments and decreases offshore into deeper marine waters. Equitability, the relation of all species abundances within an assemblage, also shows little change between the values found in shallow-marine assemblages and those found in assemblages from deeper water environments. Equitability and dominance values found in 421 assemblages from Palaeocene, Eocene, Miocene, and Pleistocene strata of the Atlantic and E Gulf of Mexico coastal plains are similar to the modern values. -from Authors

  10. Herbivory and dominance shifts among exotic and congeneric native plant species during plant community establishment

    DEFF Research Database (Denmark)

    Engelkes, Tim; Meisner, Annelein; Morriën, Elly

    2016-01-01

    in a riparian ecosystem during early establishment of invaded communities. We planted ten plant communities each consisting of three individuals of each of six exotic plant species as well as six phylogenetically related natives. Exotic plant species were selected based on a rapid recent increase in regional...... abundance, the presence of a congeneric native species, and their co-occurrence in the riparian ecosystem. All plant communities were covered by tents with insect mesh. Five tents were open on the leeward side to allow herbivory. The other five tents were completely closed in order to exclude insects...... and vertebrates. Herbivory reduced aboveground biomass by half and influenced which of the plant species dominated the establishing communities. Exposure to herbivory did not reduce the total biomass of natives more than that of exotics, so aboveground herbivory did not selectively enhance exotics during...

  11. Predicting hemispheric dominance for language production in healthy individuals using support vector machine.

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    Zago, Laure; Hervé, Pierre-Yves; Genuer, Robin; Laurent, Alexandre; Mazoyer, Bernard; Tzourio-Mazoyer, Nathalie; Joliot, Marc

    2017-12-01

    We used a Support Vector Machine (SVM) classifier to assess hemispheric pattern of language dominance of 47 individuals categorized as non-typical for language from their hemispheric functional laterality index (HFLI) measured on a sentence minus word-list production fMRI-BOLD contrast map. The SVM classifier was trained at discriminating between Dominant and Non-Dominant hemispheric language production activation pattern on a group of 250 participants previously identified as Typicals (HFLI strongly leftward). Then, SVM was applied to each hemispheric language activation pattern of 47 non-typical individuals. The results showed that at least one hemisphere (left or right) was found to be Dominant in every, except 3 individuals, indicating that the "dominant" type of functional organization is the most frequent in non-typicals. Specifically, left hemisphere dominance was predicted in all non-typical right-handers (RH) and in 57.4% of non-typical left-handers (LH). When both hemisphere classifications were jointly considered, four types of brain patterns were observed. The most often predicted pattern (51%) was left-dominant (Dominant left-hemisphere and Non-Dominant right-hemisphere), followed by right-dominant (23%, Dominant right-hemisphere and Non-Dominant left-hemisphere) and co-dominant (19%, 2 Dominant hemispheres) patterns. Co-non-dominant was rare (6%, 2 Non-Dominant hemispheres), but was normal variants of hemispheric specialization. In RH, only left-dominant (72%) and co-dominant patterns were detected, while for LH, all types were found, although with different occurrences. Among the 10 LH with a strong rightward HFLI, 8 had a right-dominant brain pattern. Whole-brain analysis of the right-dominant pattern group confirmed that it exhibited a functional organization strictly mirroring that of left-dominant pattern group. Hum Brain Mapp 38:5871-5889, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  12. Territorial behaviour and dominance hierarchy of Anthracothorax nigricollis Vieillot 1817 (Aves: Trochilidae) on food resources

    OpenAIRE

    Araujo-Silva, Lucas Eduardo; Bessa, Eduardo [UNESP

    2010-01-01

    Dominant species are those which delimit and defend territories from other individuals of the same or different species. Subordinate species are those which, furtive and sneakily, use sources of nectar from other individuals. This study aimed to describe the aggressive interactions between species of hummingbirds, define which species are dominant and which are subordinate, investigate if the sharing of resources occurs during the visits, and compare the behaviour of the dominant species in d...

  13. Plant species' origin predicts dominance and response to nutrient enrichment and herbivores in global grasslands

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    Seabloom, Eric W.; Borer, Elizabeth T.; Buckley, Yvonne M.; Cleland, Elsa E.; Davies, Kendi F.; Firn, Jennifer; Harpole, W. Stanley; Hautier, Yann; Lind, Eric M.; MacDougall, Andrew S.; Orrock, John L.; Prober, Suzanne M.; Adler, Peter B.; Anderson, T. Michael; Bakker, Jonathan D.; Biederman, Lori A.; Blumenthal, Dana M.; Brown, Cynthia S.; Brudvig, Lars A.; Cadotte, Marc; Chu, Chengjin; Cottingham, Kathryn L.; Crawley, Michael J.; Damschen, Ellen I.; Dantonio, Carla M.; DeCrappeo, Nicole M.; Du, Guozhen; Fay, Philip A.; Frater, Paul; Gruner, Daniel S.; Hagenah, Nicole; Hector, Andy; Hillebrand, Helmut; Hofmockel, Kirsten S.; Humphries, Hope C.; Jin, Virginia L.; Kay, Adam; Kirkman, Kevin P.; Klein, Julia A.; Knops, Johannes M. H.; La Pierre, Kimberly J.; Ladwig, Laura; Lambrinos, John G.; Li, Qi; Li, Wei; Marushia, Robin; McCulley, Rebecca L.; Melbourne, Brett A.; Mitchell, Charles E.; Moore, Joslin L.; Morgan, John; Mortensen, Brent; O'Halloran, Lydia R.; Pyke, David A.; Risch, Anita C.; Sankaran, Mahesh; Schuetz, Martin; Simonsen, Anna; Smith, Melinda D.; Stevens, Carly J.; Sullivan, Lauren; Wolkovich, Elizabeth; Wragg, Peter D.; Wright, Justin; Yang, Louie

    2015-01-01

    Exotic species dominate many communities; however the functional significance of species' biogeographic origin remains highly contentious. This debate is fuelled in part by the lack of globally replicated, systematic data assessing the relationship between species provenance, function and response to perturbations. We examined the abundance of native and exotic plant species at 64 grasslands in 13 countries, and at a subset of the sites we experimentally tested native and exotic species responses to two fundamental drivers of invasion, mineral nutrient supplies and vertebrate herbivory. Exotic species are six times more likely to dominate communities than native species. Furthermore, while experimental nutrient addition increases the cover and richness of exotic species, nutrients decrease native diversity and cover. Native and exotic species also differ in their response to vertebrate consumer exclusion. These results suggest that species origin has functional significance, and that eutrophication will lead to increased exotic dominance in grasslands. PMID:26173623

  14. What the hyena's laugh tells: Sex, age, dominance and individual signature in the giggling call of Crocuta crocuta

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    Weldele Mary

    2010-03-01

    Full Text Available Abstract Background Among mammals living in social groups, individuals form communication networks where they signal their identity and social status, facilitating social interaction. In spite of its importance for understanding of mammalian societies, the coding of individual-related information in the vocal signals of non-primate mammals has been relatively neglected. The present study focuses on the spotted hyena Crocuta crocuta, a social carnivore known for its complex female-dominated society. We investigate if and how the well-known hyena's laugh, also known as the giggle call, encodes information about the emitter. Results By analyzing acoustic structure in both temporal and frequency domains, we show that the hyena's laugh can encode information about age, individual identity and dominant/subordinate status, providing cues to receivers that could enable assessment of the social position of an emitting individual. Conclusions The range of messages encoded in the hyena's laugh is likely to play a role during social interactions. This call, together with other vocalizations and other sensory channels, should ensure an array of communication signals that support the complex social system of the spotted hyena. Experimental studies are now needed to decipher precisely the communication network of this species.

  15. Relationship status and relationship instability, but not dominance, predict individual differences in baseline cortisol levels.

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    Dario Maestripieri

    Full Text Available We investigated variation in baseline cortisol levels in relation to relationship status (single or in a relationship, relationship characteristics (length, stability, presence or absence of clear dominance, or individual attributes (dominant or subordinate status, relative physical attractiveness, relationship worries. Study participants were 77 men and 75 women aged between 18 and 38 years. Individuals in romantic relationships had lower cortisol levels than singles. Individuals of African ethnicity, however, showed the opposite pattern. Individuals who perceived their relationship to be highly unstable had higher cortisol levels. Aside from African-Americans, married individuals reported the lowest relationship instability and the lowest cortisol levels, followed by individuals in long-term relationships, and by individuals in short-term relationships. The presence or absence of clear dominance in the relationship, dominance status, or relationship worries did not affect cortisol levels. Therefore relationship status and relationship instability were better predictors of variation in cortisol (presumably through stress-related mechanisms than individual attributes.

  16. Relationship status and relationship instability, but not dominance, predict individual differences in baseline cortisol levels.

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    Maestripieri, Dario; Klimczuk, Amanda C E; Seneczko, Marianne; Traficonte, Daniel M; Wilson, M Claire

    2013-01-01

    We investigated variation in baseline cortisol levels in relation to relationship status (single or in a relationship), relationship characteristics (length, stability, presence or absence of clear dominance), or individual attributes (dominant or subordinate status, relative physical attractiveness, relationship worries). Study participants were 77 men and 75 women aged between 18 and 38 years. Individuals in romantic relationships had lower cortisol levels than singles. Individuals of African ethnicity, however, showed the opposite pattern. Individuals who perceived their relationship to be highly unstable had higher cortisol levels. Aside from African-Americans, married individuals reported the lowest relationship instability and the lowest cortisol levels, followed by individuals in long-term relationships, and by individuals in short-term relationships. The presence or absence of clear dominance in the relationship, dominance status, or relationship worries did not affect cortisol levels. Therefore relationship status and relationship instability were better predictors of variation in cortisol (presumably through stress-related mechanisms) than individual attributes.

  17. Modelling both dominance and species distribution provides a more complete picture of changes to mangrove ecosystems under climate change.

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    Crase, Beth; Vesk, Peter A; Liedloff, Adam; Wintle, Brendan A

    2015-08-01

    Dominant species influence the composition and abundance of other species present in ecosystems. However, forecasts of distributional change under future climates have predominantly focused on changes in species distribution and ignored possible changes in spatial and temporal patterns of dominance. We develop forecasts of spatial changes for the distribution of species dominance, defined in terms of basal area, and for species occurrence, in response to sea level rise for three tree taxa within an extensive mangrove ecosystem in northern Australia. Three new metrics are provided, indicating the area expected to be suitable under future conditions (Eoccupied ), the instability of suitable area (Einstability ) and the overlap between the current and future spatial distribution (Eoverlap ). The current dominance and occurrence were modelled in relation to a set of environmental variables using boosted regression tree (BRT) models, under two scenarios of seedling establishment: unrestricted and highly restricted. While forecasts of spatial change were qualitatively similar for species occurrence and dominance, the models of species dominance exhibited higher metrics of model fit and predictive performance, and the spatial pattern of future dominance was less similar to the current pattern than was the case for the distributions of species occurrence. This highlights the possibility of greater changes in the spatial patterning of mangrove tree species dominance under future sea level rise. Under the restricted seedling establishment scenario, the area occupied by or dominated by a species declined between 42.1% and 93.8%, while for unrestricted seedling establishment, the area suitable for dominance or occurrence of each species varied from a decline of 68.4% to an expansion of 99.5%. As changes in the spatial patterning of dominance are likely to cause a cascade of effects throughout the ecosystem, forecasting spatial changes in dominance provides new and

  18. A panel of microsatellites to individually identify leopards and its application to leopard monitoring in human dominated landscapes

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    Selvaraj Velu

    2009-12-01

    Full Text Available Abstract Background Leopards are the most widely distributed of the large cats, ranging from Africa to the Russian Far East. Because of habitat fragmentation, high human population densities and the inherent adaptability of this species, they now occupy landscapes close to human settlements. As a result, they are the most common species involved in human wildlife conflict in India, necessitating their monitoring. However, their elusive nature makes such monitoring difficult. Recent advances in DNA methods along with non-invasive sampling techniques can be used to monitor populations and individuals across large landscapes including human dominated ones. In this paper, we describe a DNA-based method for leopard individual identification where we used fecal DNA samples to obtain genetic material. Further, we apply our methods to non-invasive samples collected in a human-dominated landscape to estimate the minimum number of leopards in this human-leopard conflict area in Western India. Results In this study, 25 of the 29 tested cross-specific microsatellite markers showed positive amplification in 37 wild-caught leopards. These loci revealed varied levels of polymorphism (four-12 alleles and heterozygosity (0.05-0.79. Combining data on amplification success (including non-invasive samples and locus specific polymorphisms, we showed that eight loci provide a sibling probability of identity of 0.0005, suggesting that this panel can be used to discriminate individuals in the wild. When this microsatellite panel was applied to fecal samples collected from a human-dominated landscape, we identified 7 individuals, with a sibling probability of identity of 0.001. Amplification success of field collected scats was up to 72%, and genotype error ranged from 0-7.4%. Conclusion Our results demonstrated that the selected panel of eight microsatellite loci can conclusively identify leopards from various kinds of biological samples. Our methods can be used to

  19. Factors affecting competitive dominance of rainbow trout over brook trout in southern Appalachian streams: Implications of an individual-based model

    Energy Technology Data Exchange (ETDEWEB)

    Clark, M.E. [Univ. of Tennessee, Knoxville, TN (United States); Rose, K.A. [Oak Ridge National Lab., TN (United States)

    1997-01-01

    We used an individual-based model to examine possible explanations for the dominance of rainbow trout Oncorhynchus mykiss over brook trout Salvelinus fontinalis in southern Appalachian streams. Model simulations were used to quantify the effects on interspecific competition of (1) competitive advantage for feeding sites by rainbow trout, (2) latitudinal differences in stream temperatures, flows, and daylight, (3) year-class failures, (4) lower fecundity of brook trout, and (5) reductions in spawning habitat. The model tracks the daily spawning, growth, and survival of individuals of both species throughout their lifetime in a series of connected stream habitat units (pools, runs, or riffles). Average densities of each species based on 100-year simulations were compared for several levels of each of the five factors and for sympatric and allopatric conditions. Based on model results and empirical information, we conclude that more frequent year-class failures and the lower fecundity of brook trout are both possible and likely explanations for rainbow trout dominance, that warmer temperatures due to latitude and limited spawning habitat are possible but unlikely explanations, and that competitive advantage for feeding sites by rainbow trout is an unlikely explanation. Additional field work should focus on comparative studies of the reproductive success and the early life stage mortalities of brook and rainbow trout among Appalachian streams with varying rainbow trout dominance. 53 refs., 11 figs.

  20. Bold or cautious : behavioural characteristics and dominance in great tits

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    Verbeek, M.

    1998-01-01

    Social dominance affects territory acquisition, reproduction and survival in many species. It plays a major role in the life of an individual, and has important consequences for its fitness. Several factors that can influence dominance relationships between individuals have been well

  1. Tree species diversity promotes aboveground carbon storage through functional diversity and functional dominance.

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    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

  2. Role of functionally dominant species in varying environmental regimes: evidence for the performance-enhancing effect of biodiversity.

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    Langenheder, Silke; Bulling, Mark T; Prosser, James I; Solan, Martin

    2012-07-30

    Theory suggests that biodiversity can act as a buffer against disturbances and environmental variability via two major mechanisms: Firstly, a stabilising effect by decreasing the temporal variance in ecosystem functioning due to compensatory processes; and secondly, a performance enhancing effect by raising the level of community response through the selection of better performing species. Empirical evidence for the stabilizing effect of biodiversity is readily available, whereas experimental confirmation of the performance-enhancing effect of biodiversity is sparse. Here, we test the effect of different environmental regimes (constant versus fluctuating temperature) on bacterial biodiversity-ecosystem functioning relations. We show that positive effects of species richness on ecosystem functioning are enhanced by stronger temperature fluctuations due to the increased performance of individual species. Our results provide evidence for the performance enhancing effect and suggest that selection towards functionally dominant species is likely to benefit the maintenance of ecosystem functioning under more variable conditions.

  3. Long term prevention of disturbance induces the collapse of a dominant species without altering ecosystem function.

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    Yu, Qiang; Wu, Honghui; Wang, Zhengwen; Flynn, Dan F B; Yang, Hao; Lü, Fumei; Smith, Melinda; Han, Xingguo

    2015-09-21

    Limitation of disturbances, such as grazing and fire, is a key tool for nature reserve management and ecological restoration. While the role of these disturbances in shaping ecosystem structure and functioning has been intensively studied, less is known about the consequences of long-term prevention of grazing and fire. Based on a 31-year study, we show that relative biomass of the dominant grass, Leymus chinensis, of grasslands in northern China declined dramatically, but only after 21 years of exclusion of fire and grazing. However, aboveground net primary productivity (ANPP) did not decline accordingly due to compensatory responses of several subdominant grass species. The decline in dominance of L. chinensis was not related to gradually changing climate during the same period, whereas experimentally imposed litter removal (simulating fire), mowing (simulating grazing), fire and moderate grazing enhanced dominance of L. chinensis significantly. Thus, our findings show that disturbances can be critical to maintain the dominance of key grass species in semiarid grassland, but that the collapse of a dominant species does not necessarily result in significant change in ANPP if there are species in the community capable of compensating for loss of a dominant.

  4. Personality predicts social dominance in male domestic fowl.

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    Anna Favati

    Full Text Available Individuals in social species commonly form dominance relationships, where dominant individuals enjoy greater access to resources compared to subordinates. A range of factors such as sex, age, body size and prior experiences has to varying degrees been observed to affect the social status an individual obtains. Recent work on animal personality (i.e. consistent variation in behavioural responses of individuals demonstrates that personality can co-vary with social status, suggesting that also behavioural variation can play an important role in establishment of status. We investigated whether personality could predict the outcome of duels between pairs of morphologically matched male domestic fowl (Gallus gallus domesticus, a species where individuals readily form social hierarchies. We found that males that more quickly explored a novel arena, or remained vigilant for a longer period following the playback of a warning call were more likely to obtain a dominant position. These traits were uncorrelated to each other and were also uncorrelated to aggression during the initial part of the dominance-determining duel. Our results indicate that several behavioural traits independently play a role in the establishment of social status, which in turn can have implications for the reproductive success of different personality types.

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

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    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

  6. Leaf economics spectrum-productivity relationships in intensively grazed pastures depend on dominant species identity.

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    Mason, Norman W H; Orwin, Kate; Lambie, Suzanne; Woodward, Sharon L; McCready, Tiffany; Mudge, Paul

    2016-05-01

    Plant functional traits are thought to drive variation in primary productivity. However, there is a lack of work examining how dominant species identity affects trait-productivity relationships. The productivity of 12 pasture mixtures was determined in a 3-year field experiment. The mixtures were based on either the winter-active ryegrass (Lolium perenne) or winter-dormant tall fescue (Festuca arundinacea). Different mixtures were obtained by adding forb, legume, and grass species that differ in key leaf economics spectrum (LES) traits to the basic two-species dominant grass-white clover (Trifolium repens) mixtures. We tested for correlations between community-weighted mean (CWM) trait values, functional diversity, and productivity across all plots and within those based on either ryegrass or tall fescue. The winter-dormant forb species (chicory and plantain) had leaf traits consistent with high relative growth rates both per unit leaf area (high leaf thickness) and per unit leaf dry weight (low leaf dry matter content). Together, the two forb species achieved reasonable abundance when grown with either base grass (means of 36% and 53% of total biomass, respectively, with ryegrass tall fescue), but they competed much more strongly with tall fescue than with ryegrass. Consequently, they had a net negative impact on productivity when grown with tall fescue, and a net positive effect when grown with ryegrass. Strongly significant relationships between productivity and CWM values for LES traits were observed across ryegrass-based mixtures, but not across tall fescue-based mixtures. Functional diversity did not have a significant positive effect on productivity for any of the traits. The results show dominant species identity can strongly modify trait-productivity relationships in intensively grazed pastures. This was due to differences in the intensity of competition between dominant species and additional species, suggesting that resource-use complementarity is a

  7. Identification of Thrips Species on Garlic Fields in Hamedan Province and Determination of Dominant Species

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    Majid Mirab-balou

    2016-09-01

    Full Text Available Introduction: Garlic (Allium sativum (family Amaryllidaceae are one of important crops in Hamedan province. There are several insects and mites that by feeding on this plant cause to damage garlic yield. Among the insect pests, the most dangerous pests of garlic are thrips species (Insecta: Thysanoptera. In this group, onion thrips, Thrips tabaci Lindeman is widely distributed and is a dominant species. Its sap sucking causes tiny and silvery spots on the leaves that may spread all over the leaf surface with an unfavorable effect on yield production. In addition, imagoes and larvae living and feeding on this plant cause more serious damages. Due to serious damage of thrips in garlic fields of Hamedan province, it is necessary to identify thripsspecies for pest control programs. Materials and Methods: Thrips specimens were collected on leaves of garlic in Hamedan province (Maryanaj and Heydareh situated in the west of Iran, during 2012–2013. Herein, specimens were collected by shaking plants to white dish and specimens were kept in 70 % ethanol and transferred to the laboratory. All collected material was macerated in 5% KOH and subjected to dehydration in an ethanol series before being mounted onto glass slides. Subsequently, thrips specimens mounted onto slides in Hoyer’s medium form of the protocol given in Mirab-balou and Chen (2010. All descriptions, measurements and photos were made with a Leica DM IRB microscope, with a Leica Image 1000 system. Thrips specimens were identified by author in species level. Specimens are deposited in the collection of Department of Plant Protection, College of Agriculture, Ilam University, Iran (ILAMU. In addition, dominant thrips species were also determined. For this purpose, regular samplings were done in fields of two regions of Hamedan province every two weeks, and totally, 2040 specimens (adult were collected. Results and Discussion: The world fauna of Thysanoptera, are presently known to be

  8. Plant functional traits of dominant native and invasive species in mediterranean-climate ecosystems.

    Science.gov (United States)

    Funk, Jennifer L; Standish, Rachel J; Stock, William D; Valladares, Fernando

    2016-01-01

    The idea that dominant invasive plant species outperform neighboring native species through higher rates of carbon assimilation and growth is supported by several analyses of global data sets. However, theory suggests that native and invasive species occurring in low-resource environments will be functionally similar, as environmental factors restrict the range of observed physiological and morphological trait values. We measured resource-use traits in native and invasive plant species across eight diverse vegetation communities distributed throughout the five mediterranean-climate regions, which are drought prone and increasingly threatened by human activities, including the introduction of exotic species. Traits differed strongly across the five regions. In regions with functional differences between native and invasive species groups, invasive species displayed traits consistent with high resource acquisition; however, these patterns were largely attributable to differences in life form. We found that species invading mediterranean-climate regions were more likely to be annual than perennial: three of the five regions were dominated by native woody species and invasive annuals. These results suggest that trait differences between native and invasive species are context dependent and will vary across vegetation communities. Native and invasive species within annual and perennial groups had similar patterns of carbon assimilation and resource use, which contradicts the widespread idea that invasive species optimize resource acquisition rather than resource conservation. .

  9. Role of functionally dominant species in varying environmental regimes: evidence for the performance-enhancing effect of biodiversity

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    Langenheder Silke

    2012-07-01

    Full Text Available Abstract Background Theory suggests that biodiversity can act as a buffer against disturbances and environmental variability via two major mechanisms: Firstly, a stabilising effect by decreasing the temporal variance in ecosystem functioning due to compensatory processes; and secondly, a performance enhancing effect by raising the level of community response through the selection of better performing species. Empirical evidence for the stabilizing effect of biodiversity is readily available, whereas experimental confirmation of the performance-enhancing effect of biodiversity is sparse. Results Here, we test the effect of different environmental regimes (constant versus fluctuating temperature on bacterial biodiversity-ecosystem functioning relations. We show that positive effects of species richness on ecosystem functioning are enhanced by stronger temperature fluctuations due to the increased performance of individual species. Conclusions Our results provide evidence for the performance enhancing effect and suggest that selection towards functionally dominant species is likely to benefit the maintenance of ecosystem functioning under more variable conditions.

  10. Prediction of Dominant Forest Tree Species Using QuickBird and Environmental Data

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    Azadeh Abdollahnejad

    2017-02-01

    Full Text Available Modelling the spatial distribution of plants is one of the indirect methods for predicting the properties of plants and can be defined based on the relationship between the spatial distribution of vegetation and environmental variables. In this article, we introduce a new method for the spatial prediction of the dominant trees and species, through a combination of environmental and satellite data. Based on the basal area factor (BAF frequency for each tree species in a total of 518 sample plots, the dominant tree species were determined for each plot. Also, topographical maps of primary and secondary properties were prepared using the digital elevation model (DEM. Categories of soil and the climate maps database of the Doctor Bahramnia Forestry Plan were extracted as well. After pre-processing and processing of spectral data, the pixel values at the sample locations in all the independent factors such as spectral and non-spectral data, were extracted. The modelling rates of tree and shrub species diversity using data mining algorithms of 80% of the sampling plots were taken. Assessment of model accuracy was conducted using 20% of samples and evaluation criteria. Random forest (RF, support vector machine (SVM and k-nearest neighbor (k-NN algorithms were used for spatial distribution modelling of dominant species groups using environmental and spectral variables from 80% of the sample plots. Results showed physiographic factors, especially altitude in combination with soil and climate factors as the most important variables in the distribution of species, while the best model was created by the integration of physiographic factors (in combination with soil and climate with an overall accuracy of 63.85%. In addition, the results of the comparison between the algorithms, showed that the RF algorithm was the most accurate in modelling the diversity.

  11. Small-scale shifting mosaics of two dominant grassland species: the possible role of soil-borne pathogens

    NARCIS (Netherlands)

    Olff, H.; Hoorens, B.; De Goede, R.G.M.; Van der Putten, W.H.; Gleichman, J.M.

    2000-01-01

    We analyzed the dynamics of dominant plant species in a grazed grassland over 17 years, and investigated whether local shifts in these dominant species, leading to vegetation mosaics, could be attributed to interactions between plants and soil-borne pathogens. We found that Festuca rubra and Carer

  12. Small-scale shifting mosaics of two dominant grassland species : the possible role of soil-borne pathogens

    NARCIS (Netherlands)

    Olff, H.; Hoorens, B.; Goede, R.G.M. de; Putten, W.H. van der; Gleichman, J.M.

    2000-01-01

    We analyzed the dynamics of dominant plant species in a grazed grassland over 17 years, and investigated whether local shifts in these dominant species, leading to vegetation mosaics, could be attributed to interactions between plants and soil-borne pathogens. We found that Festuca rubra and Carex

  13. Chimpanzees copy dominant and knowledgeable individuals: implications for cultural diversity.

    Science.gov (United States)

    Kendal, Rachel; Hopper, Lydia M; Whiten, Andrew; Brosnan, Sarah F; Lambeth, Susan P; Schapiro, Steven J; Hoppitt, Will

    2015-01-01

    Evolutionary theory predicts that natural selection will fashion cognitive biases to guide when, and from whom, individuals acquire social information, but the precise nature of these biases, especially in ecologically valid group contexts, remains unknown. We exposed four captive groups of chimpanzees ( Pan troglodytes ) to a novel extractive foraging device and, by fitting statistical models, isolated four simultaneously operating transmission biases. These include biases to copy (i) higher-ranking and (ii) expert individuals, and to copy others when (iii) uncertain or (iv) of low rank. High-ranking individuals were relatively un-strategic in their use of acquired knowledge, which, combined with the bias for others to observe them, may explain reports that high innovation rates (in juveniles and subordinates) do not generate a correspondingly high frequency of traditions in chimpanzees. Given the typically low rank of immigrants in chimpanzees, a 'copying dominants' bias may contribute to the observed maintenance of distinct cultural repertoires in neighboring communities despite sharing similar ecology and knowledgeable migrants. Thus, a copying dominants strategy may, as often proposed for conformist transmission, and perhaps in concert with it, restrict the accumulation of traditions within chimpanzee communities whilst maintaining cultural diversity.

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

    Science.gov (United States)

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

    2017-12-01

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

  15. Do intrinsically dominant and subordinate species exist? A test statistic for field data

    NARCIS (Netherlands)

    Olff, Han; Bakker, Jan P.

    . We propose a new method to obtain information about processes that structure plant communities. We analysed the relationship between the presence and dominance of species across a range of habitats. A simple regression model was used to describe this relationship for each species. Based on the

  16. A global map of dominant malaria vectors

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    Sinka Marianne E

    2012-04-01

    Full Text Available Abstract Background Global maps, in particular those based on vector distributions, have long been used to help visualise the global extent of malaria. Few, however, have been created with the support of a comprehensive and extensive evidence-based approach. Methods Here we describe the generation of a global map of the dominant vector species (DVS of malaria that makes use of predicted distribution maps for individual species or species complexes. Results Our global map highlights the spatial variability in the complexity of the vector situation. In Africa, An. gambiae, An. arabiensis and An. funestus are co-dominant across much of the continent, whereas in the Asian-Pacific region there is a highly complex situation with multi-species coexistence and variable species dominance. Conclusions The competence of the mapping methodology to accurately portray DVS distributions is discussed. The comprehensive and contemporary database of species-specific spatial occurrence (currently available on request will be made directly available via the Malaria Atlas Project (MAP website from early 2012.

  17. Tree phyllosphere bacterial communities: exploring the magnitude of intra- and inter-individual variation among host species

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    Isabelle Laforest-Lapointe

    2016-08-01

    Full Text Available Background The diversity and composition of the microbial community of tree leaves (the phyllosphere varies among trees and host species and along spatial, temporal, and environmental gradients. Phyllosphere community variation within the canopy of an individual tree exists but the importance of this variation relative to among-tree and among-species variation is poorly understood. Sampling techniques employed for phyllosphere studies include picking leaves from one canopy location to mixing randomly selected leaves from throughout the canopy. In this context, our goal was to characterize the relative importance of intra-individual variation in phyllosphere communities across multiple species, and compare this variation to inter-individual and interspecific variation of phyllosphere epiphytic bacterial communities in a natural temperate forest in Quebec, Canada. Methods We targeted five dominant temperate forest tree species including angiosperms and gymnosperms: Acer saccharum, Acer rubrum, Betula papyrifera, Abies balsamea and Picea glauca. For one randomly selected tree of each species, we sampled microbial communities at six distinct canopy locations: bottom-canopy (1–2 m height, the four cardinal points of mid-canopy (2–4 m height, and the top-canopy (4–6 m height. We also collected bottom-canopy leaves from five additional trees from each species. Results Based on an analysis of bacterial community structure measured via Illumina sequencing of the bacterial 16S gene, we demonstrate that 65% of the intra-individual variation in leaf bacterial community structure could be attributed to the effect of inter-individual and inter-specific differences while the effect of canopy location was not significant. In comparison, host species identity explains 47% of inter-individual and inter-specific variation in leaf bacterial community structure followed by individual identity (32% and canopy location (6%. Discussion Our results suggest that

  18. Spatial distribution of dominant arboreal ants in a malagasy coastal rainforest: gaps and presence of an invasive species.

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    Alain Dejean

    Full Text Available We conducted a survey along three belt transects located at increasing distances from the coast to determine whether a non-random arboreal ant assemblage, such as an ant mosaic, exists in the rainforest on the Masoala Peninsula, Madagascar. In most tropical rainforests, very populous colonies of territorially dominant arboreal ant species defend absolute territories distributed in a mosaic pattern. Among the 29 ant species recorded, only nine had colonies large enough to be considered potentially territorially dominant; the remaining species had smaller colonies and were considered non-dominant. Nevertheless, the null-model analyses used to examine the spatial structure of their assemblages did not reveal the existence of an ant mosaic. Inland, up to 44% of the trees were devoid of dominant arboreal ants, something not reported in other studies. While two Crematogaster species were not associated with one another, Brachymyrmex cordemoyi was positively associated with Technomyrmex albipes, which is considered an invasive species-a non-indigenous species that has an adverse ecological effect on the habitats it invades. The latter two species and Crematogaster ranavalonae were mutually exclusive. On the other hand, all of the trees in the coastal transect and at least 4 km of coast were occupied by T. albipes, and were interconnected by columns of workers. Technomyrmex albipes workers collected from different trees did not attack each other during confrontation tests, indicating that this species has formed a supercolony along the coast. Yet interspecific aggressiveness did occur between T. albipes and Crematogaster ranavalonae, a native species which is likely territorially dominant based on our intraspecific confrontation tests. These results suggest that the Masoala rainforest is threatened by a potential invasion by T. albipes, and that the penetration of this species further inland might be facilitated by the low density of native

  19. Investigation of reactions and species dominating low temperature combustion - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Radi, P.; Knopp, G.; Johnson, M.; Boedi, A.; Gerber, T.

    2009-12-15

    This report for the Swiss Federal Office of Energy (SFOE) presents the results of work done at the Paul Scherrer Institute (PSI) in Switzerland. The project 'Investigation of reactions and species dominating low temperature combustion' involves the characterisation of species that govern ignition. A base established for the spectroscopic investigation of peroxy radicals is discussed. The two-fold aim of this project is discussed which includes the measurement of molecular features such as binding energies and dissociation patterns of well-studied and spectroscopically accessible molecules and radicals as well as the application of the measurement techniques to alkyl peroxy radicals. This was done in order to improve the database of a class of molecules playing a dominant role in combustion and atmospheric chemistry. Several experimental techniques that are to be developed to achieve these aims are looked at. Achievements made are discussed and future work to be carried out is noted.

  20. Habitats and landscapes associated with bird species in a lowland conifer-dominated ecosystem

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    Edmund J. Zlonis

    2017-06-01

    Full Text Available Human-induced effects on lowland conifer forests in hemiboreal regions are increasing because of expanded use of these northern ecosystems for raw materials, energy, and minerals as well as the potential effects of climatic changes. These forests support many breeding bird species across the Holarctic and allow the persistence of several boreal bird species in hemiboreal and even temperate regions. These bird species are of particular conservation concern as shifting patterns northward in forest composition caused by climate change will likely affect their populations. However, effective management and conservation options are limited because the specifics of these species' breeding habitats are not well understood. We modeled and mapped habitat suitability for 11 species of boreal birds that breed in the lowland conifer forests of the Agassiz Lowlands Ecological Subsection in northern Minnesota and are likely to have reduced breeding habitat in the future: Spruce Grouse (Falcipennis canadensis, Black-backed Woodpecker (Picoides arcticus, Olive-sided Flycatcher (Contopus cooperi, Yellow-bellied Flycatcher (Empidonax flaviventris, Boreal Chickadee (Poecile hudsonicus, Golden-crowned Kinglet (Regulus satrapa, Ruby-crowned Kinglet (Regulus calendula, Swainson's Thrush (Catharus ustulatus, Connecticut Warbler (Oporornis agilis, Palm Warbler (Setophaga palmarum, and Dark-eyed Junco (Junco hyemalis. Sets of 7 to 16 potential environmental covariates, including both stand-level and landscape attributes, were used to develop individual species models. Within this lowland conifer-dominated ecosystem, we found significant selection for specific forest and landscape characteristics by all but one of these species, with the best models including between one and nine variables. Habitat suitability maps were developed from these models and predictions tested with an independent dataset. Model performance depended on species, correctly predicting 56-96% of

  1. Leadership and path characteristics during walks are linked to dominance order and individual traits in dogs.

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    Zsuzsa Ákos

    2014-01-01

    Full Text Available Movement interactions and the underlying social structure in groups have relevance across many social-living species. Collective motion of groups could be based on an "egalitarian" decision system, but in practice it is often influenced by underlying social network structures and by individual characteristics. We investigated whether dominance rank and personality traits are linked to leader and follower roles during joint motion of family dogs. We obtained high-resolution spatio-temporal GPS trajectory data (823,148 data points from six dogs belonging to the same household and their owner during 14 30-40 min unleashed walks. We identified several features of the dogs' paths (e.g., running speed or distance from the owner which are characteristic of a given dog. A directional correlation analysis quantifies interactions between pairs of dogs that run loops jointly. We found that dogs play the role of the leader about 50-85% of the time, i.e. the leader and follower roles in a given pair are dynamically interchangable. However, on a longer timescale tendencies to lead differ consistently. The network constructed from these loose leader-follower relations is hierarchical, and the dogs' positions in the network correlates with the age, dominance rank, trainability, controllability, and aggression measures derived from personality questionnaires. We demonstrated the possibility of determining dominance rank and personality traits of an individual based only on its logged movement data. The collective motion of dogs is influenced by underlying social network structures and by characteristics such as personality differences. Our findings could pave the way for automated animal personality and human social interaction measurements.

  2. Effects of species' similarity and dominance on the functional and phylogenetic structure of a plant meta-community.

    Science.gov (United States)

    Chalmandrier, L; Münkemüller, T; Lavergne, S; Thuiller, W

    2015-01-01

    Different assembly processes drive the spatial structure of meta-communities (beta-diversity). Recently, functional and phylogenetic diversities have been suggested as indicators of these assembly processes. Assuming that diversity is a good proxy for niche overlap, high beta-diversity along environmental gradients should be the result of environmental filtering while low beta-diversity should stem from competitive interactions. So far, studies trying to disentangle the relative importance of these assembly processes have provided mixed results. One reason for this may be that these studies often rely on a single measure of diversity and thus implicitly make a choice on how they account for species relative abundances and how species similarities are captured by functional traits or phylogeny. Here, we tested the effect of gradually scaling the importance of dominance (the weight given to dominant vs. rare species) and species similarity (the weight given to small vs. large similarities) on resulting beta-diversity patterns of an alpine plant meta-community. To this end, we combined recent extensions of the Hill numbers framework with Pagel's phylogenetic tree transformation approach. We included functional (based on the leaf-height-seed spectrum) and phylogenetic facets of beta-diversity in our analysis and explicitly accounted for effects of environmental and spatial covariates. We found that functional beta-diversity, was high when the same weight was given to dominant vs. rare species and to large vs. small species' similarities. In contrast, phylogenetic beta-diversity was low when greater weight was given to dominant species and small species' similarities. Those results suggested that different environments along the gradients filtered different species according to their functional traits, while, the same competitive lineages dominated communities across the gradients. Our results highlight that functional vs. phylogenetic facets, presence-absence vs

  3. Floristic composition of the dry tropical forest in biological reserve (sanctuary "Los Besotes" and phenology of the dominant arboreal species (Valledupar, Cesar, Colombia

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    Mary Lee Berdugo Lattke

    2015-01-01

    Full Text Available Based on the floristic composition and structural aspects, the formation tropical dry forest of the reserve "Los Besotes" (Valledupar, Cesar; 248 y 1046m of altitude was characterized. In 35 individuals from nine dominant tree species in two forest types, the phenological characteristics were assessed. Seven monitoring were performed along one year according to the scheme of distribution of rainfall. The leaf fall in the forests of Myrcianthes aff. fragrans and Brosimum alicastrum did not exceed 20% regardless of the climatic period (drought or rainy seasons. In others dominant understory species the leaf fall was less than 40%, thus species of the canopy are classified as evergreen while those of the understory as semideciduous. Blooming peaked during the dry season while fruit production peaked during the two rainy seasons. In the forest ofBursera simaruba and Pterocarpus acapulcensis the leaf fall exceeded 60% in the dry season, while in the rainy season was only 30%. The leaf fall increased to 60% in others dominant understory species. Both canopy as well as understory species are deciduous. Blooming was observed during the dry season (December to March, and July, but it is also likely to occur in October; fruit production was observed at the end of the rainy season. In the tropical dry forest formation evergreen plant communities with low values of leaf fall (40% and deciduous communities with values greater than 60% are recognized.

  4. Mesoscale distribution of dominant diatom species relative to the hydrographical field along the Antarctic Polar Front

    Science.gov (United States)

    Smetacek, Victor; Klaas, Christine; Menden-Deuer, Susanne; Rynearson, Tatiana A.

    The quantitative distribution of dominant phytoplankton species was mapped at high spatial resolution (15 km spacing) during a quasi-synoptic, mesoscale survey of hydrographical, chemical, pigment, and zooplankton fields carried out along the Antarctic Polar Front within a grid 140×130 km 2 during austral summer. A rapid assessment method for quantifying phytoplankton species by microscopy in concentrated samples on board enabled estimation of total biomass and that of dominant species at hourly sampling intervals. The biomass distribution pattern derived from this method was remarkably coherent and correlated very well with chlorophyll concentrations and the location of different water masses covered by the grid. A "background" chlorophyll concentration of 0.5 mg m -3 in the grid could be assigned to the uniformly distributed pico- and nanophytoplankton; all higher values (up to 2.0 mg m -3) were contributed by large diatoms. Three species complexes ( Chaetoceros atlanticus/dichaeta, Pseudo-nitzschia cf. Lineola, and Thalassiothrix antarctica) contributed about one-third each to the biomass. Although all species were found throughout the study area, distinct patterns in abundance emerged: The Thalassiothrix maximum was located north of the frontal jet, Chaetoceros biomass was highest along the jet, and Pseudo-nitzschia was the most uniformly distributed of the three taxa. Since the meridional pattern of biomass and species composition persisted for about 5 weeks, despite heavy grazing pressure of small copepods, we hypothesize that the dominant species reflect the highest degree of grazer protection in the assemblage. This is accomplished by large size, needle-shaped cells, and long spines armed with barbs. We suggest that these persistent species sequester the limiting nutrient—iron—from the assemblage of smaller, less-defended species that must hence have higher turn-over rates.

  5. Temperate forest development during secondary succession: effects of soil, dominant species and management

    NARCIS (Netherlands)

    Bose, A.K.; Schelhaas, M.; Mazerolle, M.J.; Bongers, F.

    2014-01-01

    With the increase in abandoned agricultural lands in Western Europe, knowledge on the successional pathways of newly developing forests becomes urgent. We evaluated the effect of time, soil type and dominant species type (shade tolerant or intolerant) on the development during succession of three

  6. Incorporating dominant environment into individual fitness promotes cooperation in the spatial prisoners' dilemma game

    International Nuclear Information System (INIS)

    Jin, Jiahua; Shen, Chen; Chu, Chen; Shi, Lei

    2017-01-01

    Highlights: • In spatial games, each player incorporates its environment into fitness only when its environment is greater than or equal to its payoff. • The mechanism of incorporating dominant environment promotes evolution of cooperation. • The robustness of such a mechanism to promote cooperation is verified for the snowdrift game and the various interaction networks. - Abstract: In spatial evolutionary games, the fitness of each player is usually measured by its inheritance (i.e. the accumulated payoffs by playing the game with its all nearest neighbors), or by the linear combination of its inheritance and its environment (i.e. the average of its all nearest neighbors’ inheritance). However, a rational individual incorporates environment into its fitness to develop itself only when environment is dominant in real life. Here, we redefine the individual fitness as a linear combination of inheritance and environment when environment performs better than inheritance. Multiple Monte Carlo simulation results show that incorporating dominant environment can improve cooperation comparing with the traditional case, and furthermore increasing the proportion of prevailing environment can enhance cooperative level better. These findings indicate that our mechanism enhances the individual ability to adapt environment, and makes the spatial reciprocity more efficient. Besides, we also verify its robustness against different game models and various topology structures.

  7. Is browning a trigger for dominance of harmful cyanobacteria species in lakes?

    Science.gov (United States)

    Freeman, E. C.; Creed, I. F.

    2017-12-01

    "Browning" is the increase of dissolved organic matter (DOM) loads into aquatic ecosystems. It is typified by an increase in the color of surface waters as well as an increase in iron (Fe) concentrations. Browning, has been observed in boreal and temperate lakes of the northern hemisphere. This phenomena has implications for freshwater ecosystems by shifting microbial community compositions, influencing the nutritional quality of autotrophs in terms of their stoichiometry, fatty acid composition, toxin production, and methylmercury concentration, and therefore, contaminant transfer through the anabolic food web. We hypothesize that browning of lake waters will increase the dominance of particular species of cyanobacteria with adaptations to lower light, mixotrophic tendencies, and specialized Fe-uptake mechanisms. Here, we present results from a high resolution real-time monitoring campaign of an Ontario lake during the growing season where the toxin-producing cyanobacteria Plantothrix Isothrix is the dominant species. We observe the changes in phytoplankton composition, Fe concentrations, and DOM. These observations are paired with a series of controlled in-lake bottle bioassay experiments that test the role of Fe in controlling the growth of Planktothix Isothrix. In a three-way factorial design, with additions of the macronutrients phosphorus and nitrogen, we explore the effects of Fe removal and addition on the phytoplankton community composition. Understanding the interaction between the effects of browning and toxin-producing phytoplankton gives insight into the dominance of cyanobacteria in a browner world, and the potential risks to aquatic ecosystems and the services they provide.

  8. Female dominance over males in primates: self-organisation and sexual dimorphism.

    Directory of Open Access Journals (Sweden)

    Charlotte K Hemelrijk

    Full Text Available The processes that underlie the formation of the dominance hierarchy in a group are since long under debate. Models of self-organisation suggest that dominance hierarchies develop by the self-reinforcing effects of winning and losing fights (the so-called winner-loser effect, but according to 'the prior attribute hypothesis', dominance hierarchies develop from pre-existing individual differences, such as in body mass. In the present paper, we investigate the relevance of each of these two theories for the degree of female dominance over males. We investigate this in a correlative study in which we compare female dominance between groups of 22 species throughout the primate order. In our study female dominance may range from 0 (no female dominance to 1 (complete female dominance. As regards 'the prior attribute hypothesis', we expected a negative correlation between female dominance over males and species-specific sexual dimorphism in body mass. However, to our surprise we found none (we use the method of independent contrasts. Instead, we confirm the self-organisation hypothesis: our model based on the winner-loser effect predicts that female dominance over males increases with the percentage of males in the group. We confirm this pattern at several levels in empirical data (among groups of a single species and between species of the same genus and of different ones. Since the winner-loser effect has been shown to work in many taxa including humans, these results may have broad implications.

  9. [Wetlands dominated by palms (Arecaceae), emphasis in those in the New World].

    Science.gov (United States)

    Myers, Ronald L

    2013-09-01

    It is well known that most forests in humid tropical lowlands are species rich, and the popular view is that most species are represented by only a few individuals. Despite this common understanding of high richness and low species dominance, within humid tropical regions there are extensive forested ecosystems composed by only few species. These nearly monospecific forests usually occupy poorly drained soils and, except for the mangroves, are quite understudied. In this paper, I review the literature and my own field notes on more than three years studying the structure of palm swamps in Caribbean Costa Rica and Florida to describe some of the major vegetation associations in wetlands dominated by palm species in the Neotropical Region, although I also include some information about similar systems in the Old World Tropics. I mention the most abundant species that compose those palm dominated swamps and -whenever possible- describe forest structure, known distribution, and uses.

  10. Dominance, reproduction and survival in banded mongooses: towards an egalitarian social system?

    Science.gov (United States)

    de Luca, D. W.; Ginsberg, J. R.

    2001-01-01

    The banded mongoose, Mungos mungo, is a social species that forms multimale and multifemale family groups. Earlier studies suggest these family groups are relatively egalitarian with small differences in reproductive opportunities among individuals of different rank. In contrast, previous studies of other social mongooses have focused on species with more despotic control of reproduction (meerkats, Suricata suricatta, dwarf mongooses, Helogale parvula). In these species, the distribution of reproductive opportunities amongst individuals of different rank has met the predictions of reproductive skew theory: dominant individuals accrue greater reproductive benefits than subordinates, with subordinates breeding less often than dominants. In this paper we test how well two predictions of reproductive skew theory explain variance in measures of reproductive effort, and its correlates, in a wild population of banded mongooses in Queen Elizabeth National Park, Uganda. We measure dominance rank in males and females, and we investigate whether individuals of higher social rank accrue greater benefits than subordinates in terms of survival and reproduction. Banded mongoose dominance hierarchies showed linearity, but low reproductive skew. Rank was not significantly correlated with age. Furthermore, there were only small effects of dominance rank on nutritional levels, and no effects on reproduction and survival, suggesting that banded mongoose societies are indeed relatively egalitarian. No evidence of reproductive suppression was found and other forms of reproductive control were not observed. However, we do not exclude the possibility of increased reproductive competition in circumstances of higher ecological constraints. These findings show that reproductive skew theory is equally useful in explaining variation in reproduction in societies with low reproductive skew, as it is in explaining the allocation of reproductive effort in despotic social systems. Copyright 2001

  11. Study of the distribution of Malassezia species in patients with pityriasis versicolor and healthy individuals in Tehran, Iran

    Directory of Open Access Journals (Sweden)

    Zeraati Hojjat

    2004-05-01

    Full Text Available Abstract Background Pityriasis versicolor is a superficial infection of the stratum corneum which caused by a group of yeasts formerly named pityrosporium. The taxonomy of these lipophilic yeasts has recently been modified and includes seven species referred as Malassezia. The aim of this study is to compare the distribution of Malassezia species isolated from pityriasis versicolor lesions and those isolated from healthy skins. Methods Differentiation of all malassezia species performed using morphological features and physiological test including catalase reaction, Tween assimilation test and splitting of esculin. Results In pityriasis versicolor lesions, the most frequently isolated species was M. globosa (53.3%, followed by M. furfur (25.3%, M. sympodialis(9.3%, M. obtusa (8.1% and M. slooffiae (4.0%. The most frequently isolated species in the skin of healthy individuals were M. globosa, M. sympodialis, M. furfur, M. sloofiae and M. restricta which respectively made up 41.7%, 25.0%, 23.3%, 6.7% and 3.3% of the isolated species. Conclusions According to our data, M. globosa was the most prevalent species in the skin of healthy individuals which recovered only in the yeast form. However, the Mycelial form of M. globosa was isolated as the dominant species from pityriasis versicolor lesions. Therefore, the role of predisposing factors in the conversion of this yeast to mycelium and its subsequent involvement in pityriasis versicolor pathogenicity should be considered.

  12. Dispersal and individual quality in a long lived species

    Science.gov (United States)

    Cam, E.; Monnat, J.-Y.; Royle, J. Andrew

    2004-01-01

    The idea of differences in individual quality has been put forward in numerous long-term studies in long-lived species to explain differences in lifetime production among individuals. Despite the important role of individual heterogeneity in vital rates in demography, population dynamics and life history theory, the idea of 'individual quality' is elusive. It is sometimes assumed to be a static or dynamic individual characteristic. When considered as a dynamic trait, it is sometimes assumed to vary deterministically or stochastically, or to be confounded with the characteristics of the habitat. We addressed heterogeneity in reproductive performance among individuals established in higher-quality habitat in a long-lived seabird species. We used approaches to statistical inference based on individual random effects permitting quantification of heterogeneity in populations and assessment of individual variation from the population mean. We found evidence of heterogeneity in breeding probability, not success probability. We assessed the influence of dispersal on individual reproductive potential. Dispersal is likely to be destabilizing in species with high site and mate fidelity. We detected heterogeneity after dispersal, not before. Individuals may perform well regardless of quality before destabilization, including those that recruited in higher-quality habitat by chance, but only higher-quality individuals may be able to overcome the consequences of dispersal. Importantly, results differed when accounting for individual heterogeneity (an increase in mean breeding probability when individuals dispersed), or not (a decrease in mean breeding probability). In the latter case, the decrease in mean breeding probability may result from a substantial decrease in breeding probability in a few individuals and a slight increase in others. In other words, the pattern observed at the population mean level may not reflect what happens in the majority of individuals.

  13. Estimating Effects of Species Interactions on Populations of Endangered Species.

    Science.gov (United States)

    Roth, Tobias; Bühler, Christoph; Amrhein, Valentin

    2016-04-01

    Global change causes community composition to change considerably through time, with ever-new combinations of interacting species. To study the consequences of newly established species interactions, one available source of data could be observational surveys from biodiversity monitoring. However, approaches using observational data would need to account for niche differences between species and for imperfect detection of individuals. To estimate population sizes of interacting species, we extended N-mixture models that were developed to estimate true population sizes in single species. Simulations revealed that our model is able to disentangle direct effects of dominant on subordinate species from indirect effects of dominant species on detection probability of subordinate species. For illustration, we applied our model to data from a Swiss amphibian monitoring program and showed that sizes of expanding water frog populations were negatively related to population sizes of endangered yellow-bellied toads and common midwife toads and partly of natterjack toads. Unlike other studies that analyzed presence and absence of species, our model suggests that the spread of water frogs in Central Europe is one of the reasons for the decline of endangered toad species. Thus, studying population impacts of dominant species on population sizes of endangered species using data from biodiversity monitoring programs should help to inform conservation policy and to decide whether competing species should be subject to population management.

  14. The social dominance paradox.

    Science.gov (United States)

    Cook, Jennifer Louise; den Ouden, Hanneke E M; Heyes, Cecilia M; Cools, Roshan

    2014-12-01

    Dominant individuals report high levels of self-sufficiency, self-esteem, and authoritarianism. The lay stereotype suggests that such individuals ignore information from others, preferring to make their own choices. However, the nonhuman animal literature presents a conflicting view, suggesting that dominant individuals are avid social learners, whereas subordinates focus on learning from private experience. Whether dominant humans are best characterized by the lay stereotype or the animal view is currently unknown. Here, we present a "social dominance paradox": using self-report scales and computerized tasks, we demonstrate that socially dominant people explicitly value independence, but, paradoxically, in a complex decision-making task, they show an enhanced reliance (relative to subordinate individuals) on social learning. More specifically, socially dominant people employed a strategy of copying other agents when the agents' responses had a history of being correct. However, in humans, two subtypes of dominance have been identified: aggressive and social. Aggressively dominant individuals, who are as likely to "get their own way" as socially dominant individuals but who do so through the use of aggressive or Machiavellian tactics, did not use social information, even when it was beneficial to do so. This paper presents the first study of dominance and social learning in humans and challenges the lay stereotype in which all dominant individuals ignore others' views. The more subtle perspective we offer could have important implications for decision making in both the boardroom and the classroom. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Culture, morality and individual differences: comparability and incomparability across species.

    Science.gov (United States)

    Saucier, Gerard

    2018-04-19

    Major routes to identifying individual differences (in diverse species) include studies of behaviour patterns as represented in language and neurophysiology. But results from these approaches appear not to converge on some major dimensions. Identifying dimensions of human variation least applicable to non-human species may help to partition human-specific individual differences of recent evolutionary origin from those shared across species. Human culture includes learned, enforced social-norm systems that are symbolically reinforced and referenced in displays signalling adherence. At a key juncture in human evolution bullying aggression and deception-based cheating apparently became censured in the language of a moral community, enabling mutual observation coordinated in gossip, associated with external sanctions. That still-conserved cultural paradigm moralistically regulates selfish advantage-taking, with shared semantics and explicit rules. Ethics and moral codes remain critical and universal components of human culture and have a stronger imprint in language than most aspects of the currently popular Big-Five taxonomy, a model that sets out five major lines of individual-differences variation in human personality. In other species (e.g. chimpanzees), human observers might see apparent individual differences in morality-relevant traits, but not because the animals have human-analogue sanctioning systems. Removing the moral dimension of personality and other human-specific manifestations (e.g. religion) may aid in identifying those other bases of individual differences more ubiquitous across species.This article is part of the theme issue 'Diverse perspectives on diversity: multi-disciplinary approaches to taxonomies of individual differences'. © 2018 The Author(s).

  16. Mapping changing distributions of dominant species in oil-contaminated salt marshes of Louisiana using imaging spectroscopy

    Science.gov (United States)

    Beland, Michael; Roberts, Dar A.; Peterson, Seth H.; Biggs, Trent W.; Kokaly, Raymond F.; Piazza, Sarai; Roth, Keely L.; Khanna, Shruti; Ustin, Susan L.

    2016-01-01

    The April 2010 Deepwater Horizon (DWH) oil spill was the largest coastal spill in U.S. history. Monitoring subsequent change in marsh plant community distributions is critical to assess ecosystem impacts and to establish future coastal management priorities. Strategically deployed airborne imaging spectrometers, like the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS), offer the spectral and spatial resolution needed to differentiate plant species. However, obtaining satisfactory and consistent classification accuracies over time is a major challenge, particularly in dynamic intertidal landscapes.Here, we develop and evaluate an image classification system for a time series of AVIRIS data for mapping dominant species in a heavily oiled salt marsh ecosystem. Using field-referenced image endmembers and canonical discriminant analysis (CDA), we classified 21 AVIRIS images acquired during the fall of 2010, 2011 and 2012. Classification results were evaluated using ground surveys that were conducted contemporaneously to AVIRIS collection dates. We analyzed changes in dominant species cover from 2010 to 2012 for oiled and non-oiled shorelines.CDA discriminated dominant species with a high level of accuracy (overall accuracy = 82%, kappa = 0.78) and consistency over three imaging dates (overall2010 = 82%, overall2011 = 82%, overall2012 = 88%). Marshes dominated by Spartina alterniflora were the most spatially abundant in shoreline zones (≤ 28 m from shore) for all three dates (2010 = 79%, 2011 = 61%, 2012 = 63%), followed by Juncus roemerianus (2010 = 11%, 2011 = 19%, 2012 = 17%) and Distichlis spicata (2010 = 4%, 2011 = 10%, 2012 = 7%).Marshes that were heavily contaminated with oil exhibited variable responses from 2010 to 2012. Marsh vegetation classes converted to a subtidal, open water class along oiled and non-oiled shorelines that were similarly situated in the landscape. However, marsh loss along oil-contaminated shorelines

  17. Using Imaging Spectroscopy to Map Changing Distributions of Dominant Species in Oil-Contaminated Salt Marshes of Louisiana

    Science.gov (United States)

    Beland, M. C.; Roberts, D. A.; Peterson, S.; Biggs, T. W.; Kokaly, R. F.; Piazza, S.; Roth, K. L.; Khanna, S.; Ustin, S.

    2016-12-01

    The April 2010 Deepwater Horizon (DWH) oil spill was the largest coastal spill in U.S. history. Monitoring subsequent change in marsh plant community distributions is critical to assess ecosystem impacts and to establish future coastal management priorities. Strategically deployed airborne imaging spectrometers, like the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS), offer the spectral and spatial resolution needed to differentiate plant species. However, obtaining satisfactory and consistent classification accuracies over time is a major challenge, particularly in dynamic intertidal landscapes. Here, we develop and evaluate an image classification system for a time series of AVIRIS data for mapping dominant species in a heavily oiled salt marsh ecosystem. Using field-referenced image endmembers and canonical discriminant analysis (CDA), we classified 21 AVIRIS images acquired during the fall of 2010, 2011 and 2012. Classification results were evaluated using ground surveys that were conducted contemporaneously to AVIRIS collection dates. We analyzed changes in dominant species cover from 2010-2012 for oiled and non-oiled shorelines. CDA discriminated dominant species with a high level of accuracy (overall accuracy = 82%, kappa = 0.78) and consistency over three imaging dates (overall2010 = 82%, overall2011 = 82%, overall2012 = 88%). Marshes dominated by Spartina alterniflora were the most spatially abundant in shoreline zones (≤ 28m from shore) for all three dates (2010 = 79%, 2011 = 61%, 2012 = 63%), followed by Juncus roemerianus (2010 = 11%, 2011 = 19%, 2012 = 17%) and Distichlis spicata (2010 = 4%, 2011 = 10%, 2012 = 7%). Marshes that were heavily contaminated with oil exhibited variable responses from 2010-2012. Marsh vegetation classes converted to a subtidal, open water class along oiled and non-oiled shorelines that were similarly situated in the landscape. However, marsh loss along oil-contaminated shorelines doubled that of non

  18. Do species differ in their ability to coexist with the dominant alien Lupinus polyphyllus? A comparison between two distinct invaded ranges and a native range

    Directory of Open Access Journals (Sweden)

    Martin Hejda

    2013-06-01

    Full Text Available The community-level impacts of invasive plants are likely to vary depending on the character of native species of the target communities and their ability to thrive within the stands of the dominant alien invader. Therefore, I examined the response of native species richness to the cover of the dominant alien Lupinus polyphyllus in two distinct invaded ranges: Czech Republic (Central Europe and New Zealand. I compared the relation between native species richness and the cover of the dominant alien L. polyphyllus with that in its native range, Pacific Northwest, USA.In the native range, I found no response of native species richness to the cover of L. polyphyllus. In the Czech Republic (central Europe, the richness of native species related to it negativelly, but the relation was only marginally significant. Contrary to that, the richness of species native to New Zealand related to the cover of L. polyphyllus strongly negatively and the negative relation was significantly stronger than that of species native to Europe.Of the two invaded ranges, species native to New Zealand have been documented to be much more vulnerable to the conditions associated with the invasion and dominance of L. polyphyllus, compared to species native to central Europe. This principle has been shown both across these two invaded ranges and in New Zealand, where the aliens of european origin successfully coexist with the dominant invasive alien L. polyphyllus. Similarly, species in the native range of L. polyphyllus showed no relation to its cover, indicating their ability to thrive even in dense stands of this dominant species.

  19. Decomposition of Carex and Sphagnum litter in two mesotrophic fens differing in dominant plant species

    NARCIS (Netherlands)

    Scheffer, R.A.; Van Logtestijn, R. S P; Verhoeven, J. T A

    2001-01-01

    Peatlands can be classified into fens and bogs based on their hydrology. Development of fens to bogs is accompanied by the invasion of Sphagnum species. The purpose of this study was to determine how the decomposition process in fens is influenced by the transition from a vascular plant-dominated

  20. Stand, species, and individual traits impact transpiration in historically disturbed forests.

    Science.gov (United States)

    Blakely, B.; Rocha, A. V.; McLachlan, J. S.

    2017-12-01

    Historic logging disturbances have changed the structure and species composition of most Northern temperate forests. These changes impact the process of transpiration - which in turn impacts canopy surface temperature - but the links among structure, composition, and transpiration remain unclear. For this reason, ecosystem models typically use simplified structure and composition to simulate the impact of disturbances on forest transpiration. However, such simplifications ignore real variability among stands, species, and individual trees that may strongly influence transpiration across spatial and temporal scales. To capture this variability, we monitored transpiration in 48 individual trees of multiple species in both undisturbed (400+ yr) and historically logged (80 - 120 yr) forests. Using modern and historic forest surveys, we upscaled our observations to stand and regional scales to identify the key changes impacting transpiration. We extended these inferences by establishing a relationship between transpiration and measured surface temperature, linking disturbance-induced changes in structure and composition to local and regional climate. Despite greater potential evapotranspiration and basal area, undisturbed forest transpired less than disturbed (logged) forest. Transpiration was a strong predictor of surface temperature, and the canopy surface was warmer in undisturbed forest. Transpiration differences among disturbed and undisturbed forests resulted from (1) lesser transpiration and dampened seasonality in evergreen species (2) greater transpiration in younger individuals within a species, and (3) strong transpiration by large individuals. When transpiration was scaled to the stand or regional level in a simplified manner (e.g. a single transpiration rate for all deciduous individuals), the resulting estimates differed markedly from the original. Stand- species- and individual-level traits are therefore essential for understanding how transpiration and

  1. Partilha de néctar de Eucalyptus spp., territorialidade e hierarquia de dominância em beija-flores (Aves: Trochilidae) no sudeste do Brasil

    OpenAIRE

    Antunes, Alexsander Z. [UNESP

    2003-01-01

    Territorial behavior in hummingbirds minimizes competition through aggressive interactions, resulting in a dominance hierarchy among species and individuals. Interactions among seven hummingbird species visiting flowering eucalyptus in the Floresta Estadual near Rio Claro, São Paulo, in southeastern Brazil, were studied. Dominance was determined by weight and size with the largest species being the most dominant. Time spent in defense and the number of aggressive interactions were greater tha...

  2. Oceanographic mechanisms that possibly explain dominance of neritic-tropical zooplankton species assemblages around the Islas Marías Archipelago, Mexico

    Directory of Open Access Journals (Sweden)

    Jaime Gómez-Gutiérrez

    2014-11-01

    Full Text Available The nearshore zooplankton species assemblage, identified per taxonomic groups (20 and per species for 12 selected groups, was analyzed from samples collected during November 2010 at four volcanic islands of the Islas Marías Archipelago (IMA, located 90-120 km offshore Nayarit, Mexico. From chlorophyll-a concentration and zooplankton biovolume perspective mesotrophic conditions prevailed in comparison with the Gulf of California during November. Crustaceans numerically dominated the zooplankton assemblage (92.3% [Copepoda (79.2%, Decapoda larvae (4.7%, Cladocera (3.7%, Mysidacea (2.7%, and Euphausiacea (2.0%]. The other 15 taxonomic groups (7.7% combined accounted each one less than 1.5% of the relative abundance. Species richness of selected taxa (~56%> included 259 taxa (121 identified to species, 117 to genus, and 21 not identified. Tropical species from neritic affinity clearly dominated zooplankton assemblage around IMA. Five tropical Copepoda species [Calanopia minor (Dana, Clausocalanus jobei Frost & Fleminger, Acrocalanus gibber Giesbrecht, Canthocalanus pauper (Giesbrecht, and Centropages furcatus (Dana], a cladoceran Pseudevadne tergestina (Claus, and a Mysidacea species (Mysidium reckettsi Harrison & Bowman dominated the zooplankton assemblage (accounting about 55% of total abundance of the identified species. Except C. furcatus, all these species are not abundant at oceanic regions of the central and northern Gulf of California. The similarity of multiple neritic and tropical species in the zooplankton assemblage from IMA and Cape Corrientes suggests strong coastal-insular plankton connectivity. Episodic current plumes associated with anomalous intense rivers discharge during rainy years, eddies generated by coastal upwelling event that move offshore, and northward regional oceanic circulation are the most likely mesoscale oceanographic processes that cause costal tropical zooplankton drift enhancing coastal-Archipelago species

  3. Economically important species dominate aboveground carbon storage in forests of southwestern Amazonia

    Directory of Open Access Journals (Sweden)

    N. Galia Selaya

    2017-06-01

    Full Text Available Tree species in tropical forests provide economically important goods and ecosystem services. In submontane forests of southwestern Amazonia, we investigated the degree to which tree species important for subsistence and trade contribute to aboveground carbon storage (AGC. We used 41 1-hectare plots to determine the species abundance, basal area, and AGC of stems > 10 cm diameter at breast height (dbh. Economically important taxa were classified using ethnobotanical studies and according to their stem density. These taxa (n = 263 accounted for 45% of total stems, 53% of total basal area, and 56% of total AGC, significantly more than taxa with minor or unknown uses (Welch test at p 40 cm and few stems in regeneration classes of dbh < 10 to 20 cm (e.g., Bertholletia excelsa, Cariniana spp., Cedrelinga spp., Ceiba spp., Dipteryx spp., whereas dominant Tetragastris spp., and Pseudolmedia spp. had most stems in low diameter classes and a median diameter of < 30 cm. Bertholletia excelsa, with 1.5 stems per hectare, showed the highest basal area of any species and accounted for 9% of AGC (11 Mg/ha, twice that of the second-ranking species. Our study shows that economic importance and carbon stocks in trees are closely linked in southwestern Amazonia. Unplanned harvests can disrupt synergistic dual roles altering carbon stocks temporally or permanently. Precautionary measures based on species ecology, demography, and regeneration traits should be at the forefront of REDD+ to reconcile maximum harvesting limits, biodiversity conservation, and sustainable forest management.

  4. Ecological interactions among Saccharomyces cerevisiae strains: insight into the dominance phenomenon.

    Science.gov (United States)

    Pérez-Torrado, Roberto; Rantsiou, Kalliopi; Perrone, Benedeta; Navarro-Tapia, Elisabeth; Querol, Amparo; Cocolin, Luca

    2017-03-07

    This study investigates the behaviour of Saccharomyces cerevisiae strains, in order to obtain insight into the intraspecies competition taking place in mixed populations of this species. Two strains of S. cerevisiae, one dominant and one non-dominant, were labelled and mixed, and individual fermentations were set up to study the transcriptomes of the strains by means of RNA-seq. The results obtained suggest that cell-to-cell contact and aggregation, which are driven by the expression of genes that are associated with the cell surface, are indispensable conditions for the achievement of dominance. Observations on mixed aggregates, made up of cells of both strains, which were detected by means of flow cytometry, have confirmed the transcriptomic data. Furthermore, overexpression of the SSU1 gene, which encodes for a transporter that confers resistance to sulphites, provides an ecological advantage to the dominant strain. A mechanistic model is proposed that sheds light on the dominance phenomenon between different strains of the S. cerevisiae species. The collected data suggest that cell-to-cell contact, together with differential sulphite production and resistance is important in determining the dominance of one strain over another.

  5. Sympatric Dreissena species in the Meuse River : towards a dominance shift from zebra to quagga mussels

    OpenAIRE

    Marescaux, Jonathan; Boets, Pieter; Lorquet, Julien; Sablon, Rose; Van Doninck, Karine; Beisel, Jean-Nicolas

    2015-01-01

    The rapid spread of the quagga mussel, Dreissena rostriformis, in Western Europe is of particular concern since the species is known to have serious ecological and economic impacts, similar to those of the well-established zebra mussel, Dreissena polymorpha. This study aimed (1) to provide an update on the quagga mussel distribution in several Belgian inland waterways, and (2) to check if a shift in dominance between Dreissena species is occurring. Using density measurements and artificial su...

  6. Hemispheric metacontrol and cerebral dominance in healthy individuals investigated by means of chimeric faces.

    Science.gov (United States)

    Urgesi, Cosimo; Bricolo, Emanuela; Aglioti, Salvatore M

    2005-08-01

    Cerebral dominance and hemispheric metacontrol were investigated by testing the ability of healthy participants to match chimeric, entire, or half faces presented tachistoscopically. The two hemi-faces compounding chimeric or entire stimuli were presented simultaneously or asynchronously at different exposure times. Participants did not consciously detect chimeric faces for simultaneous presentations lasting up to 40 ms. Interestingly, a 20 ms separation between each half-chimera was sufficient to induce detection of conflicts at a conscious level. Although the presence of chimeric faces was not consciously perceived, performance on chimeric faces was poorer than on entire- and half-faces stimuli, thus indicating an implicit processing of perceptual conflicts. Moreover, the precedence of hemispheric stimulation over-ruled the right hemisphere dominance for face processing, insofar as the hemisphere stimulated last appeared to influence the response. This dynamic reversal of cerebral dominance, however, was not caused by a shift in hemispheric specialization, since the level of performance always reflected the right hemisphere specialization for face recognition. Thus, the dissociation between hemispheric dominance and specialization found in the present study hints at the existence of hemispheric metacontrol in healthy individuals.

  7. Scaling down from species to individuals: a flower-visitation network between individual honeybees and thistle plants

    DEFF Research Database (Denmark)

    Dupont, Yoko; Nielsen, Kristian T.; Olesen, Jens Mogens

    2011-01-01

    stems and monitored all floral visits. The constructed bipartite network of individual plants and bees had a high connectance and low nestedness, but it was not significantly modular. Frequency distributions of number of links per species (i.e. linkage level) had their best fit to a truncated power law......, and interactions were asymmetrical. Unipartite networks of either plants or bees had exceedingly short average path length and high clustering. Linkage level of plants increased with their number of flower heads and height of inflorescence (floral display parameters). Overall, the individual network of honeybees...... and thistles was denser linked than what is known from species pollination networks. Characteristics of both plants (e.g. floral display) and animals (e.g. foraging behaviour) are likely to generate this intra–specific, inter–individual link pattern. Such features of individual–individual networks may scale up...

  8. Remote-Sensed Monitoring of Dominant Plant Species Distribution and Dynamics at Jiuduansha Wetland in Shanghai, China

    Directory of Open Access Journals (Sweden)

    Wenpeng Lin

    2015-08-01

    Full Text Available Spartina alterniflora is one of the most hazardous invasive plant species in China. Monitoring the changes in dominant plant species can help identify the invasion mechanisms of S. alterniflora, thereby providing scientific guidelines on managing or controlling the spreading of this invasive species at Jiuduansha Wetland in Shanghai, China. However, because of the complex terrain and the inaccessibility of tidal wetlands, it is very difficult to conduct field experiments on a large scale in this wetland. Hence, remote sensing plays an important role in monitoring the dynamics of plant species and its distribution on both spatial and temporal scales. In this study, based on multi-spectral and high resolution (<10 m remote sensing images and field observational data, we analyzed spectral characteristics of four dominant plant species at different green-up phenophases. Based on the difference in spectral characteristics, a decision tree classification was built for identifying the distribution of these plant species. The results indicated that the overall classification accuracy for plant species was 87.17%, and the Kappa Coefficient was 0.81, implying that our classification method could effectively identify the four plant species. We found that the area of Phragmites australi showed an increasing trend from 1997 to 2004 and from 2004 to 2012, with an annual spreading rate of 33.77% and 31.92%, respectively. The area of Scirpus mariqueter displayed an increasing trend from 1997 to 2004 (12.16% per year and a decreasing trend from 2004 to 2012 (−7.05% per year. S. alterniflora has the biggest area (3302.20 ha as compared to other species, accounting for 51% of total vegetated area at the study region in 2012. It showed an increasing trend from 1997 to 2004 and from 2004 to 2012, with an annual spreading rate of 130.63% and 28.11%, respectively. As a result, the native species P. australi was surrounded and the habitats of S. mariqueter were

  9. Dominance Hierarchies in Young Children

    Science.gov (United States)

    Edelman, Murray S.; Omark, Donald R.

    1973-01-01

    This study uses the ethological approach of seeking species characteristics and phylogenetic continuities in an investigation of human behavior. Among primates a striking consistency is the presence of some form of dominance hierarchy in many species. The present study examines peer group dominance hierarchies as they are perceived by children in…

  10. Does social status within a dominance hierarchy mediate individual growth, residency and relocation?

    Science.gov (United States)

    Akbaripasand, Abbas; Ramezani, J; Krkosek, Martin; Lokman, P Mark; Closs, Gerard P

    2014-11-01

    The availability of food, and hence energy, is known to influence the abundance, habitat choice and growth of individuals. In contrast, there is a paucity of knowledge on how the interaction of energy supply and social status determines patterns of residency and movement. This study tests whether the presence of conspecifics and an individual's social status in relation to food supply influence the fitness and movement of a drift-feeding fish (Galaxias fasciatus). Using an information-theoretic approach (AIC), our analysis indicated that the most parsimonious model of fish movement among pools was one that included food supply, social rank and fish relative growth rate. Our results indicated that subordinate fish relocated more frequently compared to dominant fish, most likely as a consequence of intra-specific competition that limited the access of these smaller fish to resources and constrained their growth. Our results suggest that energy constraints may force individuals to explore new habitats in an effort to find more energetically profitable patches. We conclude that intra-specific competition mediated through the social hierarchy amongst closely interacting individuals plays a key role in determining individual growth, residency and relocation.

  11. Distribution of dominant arbuscular mycorrhizal fungi among five plant species in undisturbed vegetation of a coastal grassland

    DEFF Research Database (Denmark)

    Holtgrewe-Stukenbrock, Eva; Rosendahl, Søren

    2005-01-01

    Most plant species in mixed grassland vegetation are colonized by arbuscular mycorrhizal (AM) fungi. Previous studies have reported differences in host preferences among AM fungi, although the fungi are known to lack host specificity. In the present study, the distribution of phylogenetic groups...... of AM fungi belonging to a clade of Glomus species was studied in five plant species from a coastal grassland in Denmark. The occurrence of the fungi was determined by PCR analyses of fungal large subunit ribosomal DNA sequences amplified from root fragments using a specific primer set. The results...... showed that the dominant Glomus species were able to colonize all the studied plant species, supporting the view that the AM fungi represent a large underground interconnecting mycelial network....

  12. Tree species richness, diversity, and regeneration status in different oak (Quercus spp. dominated forests of Garhwal Himalaya, India

    Directory of Open Access Journals (Sweden)

    Sushma Singh

    2016-09-01

    Full Text Available Himalayan forests are dominated by different species of oaks (Quercus spp. at different altitudes. These oaks are intimately linked with hill agriculture as they protect soil fertility, watershed, and local biodiversity. They also play an important role in maintaining ecosystem stability. This work was carried out to study the diversity and regeneration status of some oak forests in Garhwal Himalaya, India. A total of 18 tree species belonging to 16 genera and 12 families were reported from the study area. Species richness varied for trees (4–7, saplings (3–10, and seedlings (2–6. Seedling and sapling densities (Ind/ha varied between 1,376 Ind/ha and 9,600 Ind/ha and 167 Ind/ha and 1,296 Ind/ha, respectively. Species diversity varied from 1.27 to 1.86 (trees, from 0.93 to 3.18 (saplings, and from 0.68 to 2.26 (seedlings. Total basal area (m2/ha of trees and saplings was 2.2–87.07 m2/ha and 0.20–2.24 m2/ha, respectively, whereas that of seedlings varied from 299 cm2/ha to 8,177 cm2/ha. Maximum tree species (20–80% had “good” regeneration. Quercus floribunda, the dominant tree species in the study area, showed “poor” regeneration, which is a matter of concern, and therefore, proper management and conservation strategies need to be developed for maintenance and sustainability of this oak species along with other tree species that show poor or no regeneration.

  13. Describing the organization of dominance relationships by dominance-directed tree method.

    Science.gov (United States)

    Izar, Patrícia; Ferreira, Renata G; Sato, Takechi

    2006-02-01

    Methods to describe dominance hierarchies are a key tool in primatology studies. Most current methods are appropriate for analyzing linear and near-linear hierarchies; however, more complex structures are common in primate groups. We propose a method termed "dominance-directed tree." This method is based on graph theory and set theory to analyze dominance relationships in social groups. The method constructs a transitive matrix by imposing transitivity to the dominance matrix and produces a graphical representation of the dominance relationships, which allows an easy visualization of the hierarchical position of the individuals, or subsets of individuals. The method is also able to detect partial and complete hierarchies, and to describe situations in which hierarchical and nonhierarchical principles operate. To illustrate the method, we apply a dominance tree analysis to artificial data and empirical data from a group of Cebus apella. Copyright 2006 Wiley-Liss, Inc.

  14. The socialization of dominance: peer group contextual effects on homophobic and dominance attitudes.

    Science.gov (United States)

    Poteat, V Paul; Espelage, Dorothy L; Green, Harold D

    2007-06-01

    Using the framework of social dominance theory, the current investigation tested for the contextual effects of adolescent peer groups on individuals' homophobic and social dominance attitudes. Results from multilevel models indicated that significant differences existed across peer groups on homophobic attitudes. In addition, these differences were accounted for on the basis of the hierarchy-enhancing or -attenuating climate of the group. A group socialization effect on individuals' social dominance attitudes over time was also observed. Furthermore, the social climate of the peer group moderated the stability of individuals' social dominance attitudes. Findings support the need to examine more proximal and informal group affiliations and earlier developmental periods in efforts to build more comprehensive theoretical models explaining when and how prejudiced and dominance attitudes are formed and the way in which they are perpetuated. (c) 2007 APA, all rights reserved.

  15. Quantitative analysis of diet structure by real-time PCR, reveals different feeding patterns by two dominant grasshopper species

    Science.gov (United States)

    Huang, Xunbing; Wu, Huihui; McNeill, Mark Richard; Qin, Xinghu; Ma, Jingchuan; Tu, Xiongbing; Cao, Guangchun; Wang, Guangjun; Nong, Xiangqun; Zhang, Zehua

    2016-01-01

    Studies on grasshopper diets have historically employed a range of methodologies, each with certain advantages and disadvantages. For example, some methodologies are qualitative instead of quantitative. Others require long experimental periods or examine population-level effects, only. In this study, we used real-time PCR to examine diets of individual grasshoppers. The method has the advantage of being both fast and quantitative. Using two grasshopper species, Oedaleus asiaticus and Dasyhippus barbipes, we designed ITS primer sequences for their three main host plants, Stipa krylovii, Leymus chinensis and Cleistogenes squarrosa and used real-time PCR method to test diet structure both qualitatively and quantitatively. The lowest detection efficiency of the three grass species was ~80% with a strong correlation between actual and PCR-measured food intake. We found that Oedaleus asiaticus maintained an unchanged diet structure across grasslands with different grass communities. By comparison, Dasyhippus barbipes changed its diet structure. These results revealed why O. asiaticus distribution is mainly confined to Stipa-dominated grassland, and D. barbipes is more widely distributed across Inner Mongolia. Overall, real-time PCR was shown to be a useful tool for investigating grasshopper diets, which in turn offers some insight into grasshopper distributions and improved pest management. PMID:27562455

  16. Binocular summation and other forms of non-dominant eye contribution in individuals with strabismic amblyopia during habitual viewing.

    Directory of Open Access Journals (Sweden)

    Brendan T Barrett

    Full Text Available BACKGROUND: Adults with amblyopia ('lazy eye', long-standing strabismus (ocular misalignment or both typically do not experience visual symptoms because the signal from weaker eye is given less weight than the signal from its fellow. Here we examine the contribution of the weaker eye of individuals with strabismus and amblyopia with both eyes open and with the deviating eye in its anomalous motor position. METHODOLOGY/RESULTS: The task consisted of a blue-on-yellow detection task along a horizontal line across the central 50 degrees of the visual field. We compare the results obtained in ten individuals with strabismic amblyopia with ten visual normals. At each field location in each participant, we examined how the sensitivity exhibited under binocular conditions compared with sensitivity from four predictions, (i a model of binocular summation, (ii the average of the monocular sensitivities, (iii dominant-eye sensitivity or (iv non-dominant-eye sensitivity. The proportion of field locations for which the binocular summation model provided the best description of binocular sensitivity was similar in normals (50.6% and amblyopes (48.2%. Average monocular sensitivity matched binocular sensitivity in 14.1% of amblyopes' field locations compared to 8.8% of normals'. Dominant-eye sensitivity explained sensitivity at 27.1% of field locations in amblyopes but 21.2% in normals. Non-dominant-eye sensitivity explained sensitivity at 10.6% of field locations in amblyopes but 19.4% in normals. Binocular summation provided the best description of the sensitivity profile in 6/10 amblyopes compared to 7/10 of normals. In three amblyopes, dominant-eye sensitivity most closely reflected binocular sensitivity (compared to two normals and in the remaining amblyope, binocular sensitivity approximated to an average of the monocular sensitivities. CONCLUSIONS: Our results suggest a strong positive contribution in habitual viewing from the non-dominant eye in

  17. Insect radiosensitivity: dose curves and dose-fractionation studies of dominant lethal mutations in the mature sperm of 4 insect species

    International Nuclear Information System (INIS)

    LaChance, L.E.; Graham, C.K.

    1984-01-01

    Males of 4 species of insects: Musca domestica L. (housefly) (Diptera), Oncopeltus fasciatus (Dallas) (milkweed bug) (Hemiptera), Anagasta kuhniella (Zeller) (mealmoth) (Lepidoptera) and Heliothis virescens (Fab.) (tobacco budworm) (Lepidoptera) were irradiated as adults. Dose-response curves for the induction of dominant lethal mutations in the mature sperm were constructed. The curves were analyzed mathematically and compared with theoretical computer simulated curves requiring 1, 2, 4, 8 and 16 'hits' for the induction of a dominant lethal mutation. The 4 species belonging to 3 different orders of insects showed a wide range in radiation sensitivity and vastly different dose-response curves. When the data were analyzed by several mathematical models the authors found that a logistic response curve gave reasonably good fit with vastly different parameters for the 4 species. Dose-fractionation experiments showed no reduction in the frequency of lethal mutations induced in any species when an acute dose was fractionated into 2 equal exposures separated by an 8-h period. (Auth.)

  18. Molecular correlates of social dominance: a novel role for ependymin in aggression.

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    Lynne U Sneddon

    2011-04-01

    Full Text Available Theoretical and empirical studies have sought to explain the formation and maintenance of social relationships within groups. The resulting dominance hierarchies have significant fitness and survival consequences dependent upon social status. We hypothesised that each position or rank within a group has a distinctive brain gene expression profile that correlates with behavioural phenotype. Furthermore, transitions in rank position should determine which genes shift in expression concurrent with the new dominance status. We used a custom cDNA microarray to profile brain transcript expression in a model species, the rainbow trout, which forms tractable linear hierarchies. Dominant, subdominant and submissive individuals had distinctive transcript profiles with 110 gene probes identified using conservative statistical analyses. By removing the dominant, we characterised the changes in transcript expression in sub-dominant individuals that became dominant demonstrating that the molecular transition occurred within 48 hours. A strong, novel candidate gene, ependymin, which was highly expressed in both the transcript and protein in subdominants relative to dominants, was tested further. Using antibody injection to inactivate ependymin in pairs of dominant and subdominant zebrafish, the subdominant fish exhibited a substantial increase in aggression in parallel with an enhanced competitive ability. This is the first study to characterise the molecular signatures of dominance status within groups and the first to implicate ependymin in control of aggressive behaviour. It also provides evidence for indirect genetic effect models in which genotype/phenotype of an individual is influenced by conspecific interactions within a group. The variation in the molecular profile of each individual within a group may offer a new explanation of intraspecific variation in gene expression within undefined groups of animals and provides new candidates for empirical

  19. A Five Species Cyclically Dominant Evolutionary Game with Fixed Direction: A New Way to Produce Self-Organized Spatial Patterns

    Directory of Open Access Journals (Sweden)

    Yibin Kang

    2016-08-01

    Full Text Available Cyclically dominant systems are hot issues in academia, and they play an important role in explaining biodiversity in Nature. In this paper, we construct a five-strategy cyclically dominant system. Each individual in our system changes its strategy along a fixed direction. The dominant strategy can promote a change in the dominated strategy, and the dominated strategy can block a change in the dominant strategy. We use mean-field theory and cellular automaton simulation to discuss the evolving characters of the system. In the cellular automaton simulation, we find the emergence of spiral waves on spatial patterns without a migration rate, which suggests a new way to produce self-organized spatial patterns.

  20. Duration of memory of dominance relationships in a group living cichlid

    Science.gov (United States)

    Hotta, Takashi; Takeyama, Tomohiro; Jordan, Lyndon Alexander; Kohda, Masanori

    2014-09-01

    Animal contests are costly and tend to escalate when rivals have similar competitive abilities. Individuals that remember dominance relationships with rivals may avoid repeated agonistic interactions and hence avoid the costs of repeated escalation of contests. However, it can be difficult to experimentally disentangle the effects of memory from those of loser effects (losers behaving subordinately due to prior defeats). Here, we test whether loser effects or individual memory mediate contest behaviour in the African cichlid, Julidochromis transcriptus. We find that on days 3 and 5 after initial contests, losers display subordinate behaviour to contest winners but not to novel contestants. However, this effect disappears after 7 days, at which time losers do not display subordinate behaviour to either rival. These results show that (1) this fish can recall a previously dominant contestant for up to 5 days and (2) as no subordinate displays were shown to the novel contestant, there are no evidences for loser effects in this species. Such short-term memory of past interactions may have broad significance in social species with repeated interactions.

  1. Increased prevalences of left-handedness and left-eye sighting dominance in individuals with Williams-Beuren syndrome

    NARCIS (Netherlands)

    J.W. van Strien (Jan)

    2005-01-01

    textabstractHandedness and eye sighting dominance were assessed in a sample of 50 individuals (25 male, 25 female; aged 5 – 38 years) with Williams-Beuren syndrome (WBS). The prevalences of left-handedness and left-eyedness were compared to the normative prevalences in the general population. We

  2. Dominance of the multicoloured Asian lady beetle Harmonia axyridis in an undisturbed wild meadow ecosystem

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    Élise Bélanger

    2011-12-01

    Full Text Available Fifteen years after its arrival in Quebec (Canada, the multicoloured Asian lady beetle Harmonia axyridis (Pallas 1773 (Coleoptera: Coccinellidae has become one of the dominant coccinellid species in agricultural, forested and urban areas. Several studies conducted in North American agricultural ecosystems show that the arrival of H. axyridis and other exotic coccinellid species was followed by decreases in the populations of native coccinellid species. In this study, the abundances of H. axyridis and other native and exotic species were determined in an undisturbed wild meadow located in a protected area. In 2009 and 2010, mainly Solidago canadensis L. (Asteraceae and Asclepias syriaca L. (Asclepiadaceae infested with aphids were surveyed. A total of 1522 individuals, belonging to seven different species, were recorded. In 2009, on all the plants monitored, H. axyridis was clearly the dominant species (69% of the coccinellid assemblage. In addition, this exotic species constituted 84% of the coccinellid assemblage, including Propylea quatuordecimpunctata (L. and Coccinella septempunctata (L. It is likely the dominance of the eurytopic Asian lady beetle in agricultural, forested, urban and undisturbed open ecosystems, poses a threat to native lady beetles. These results also provide evidence that undisturbed wild meadow ecosystems will not constitute a natural refuge from Harmonia axyridis for native species of lady beetles.

  3. Global network structure of dominance hierarchy of ant workers.

    Science.gov (United States)

    Shimoji, Hiroyuki; Abe, Masato S; Tsuji, Kazuki; Masuda, Naoki

    2014-10-06

    Dominance hierarchy among animals is widespread in various species and believed to serve to regulate resource allocation within an animal group. Unlike small groups, however, detection and quantification of linear hierarchy in large groups of animals are a difficult task. Here, we analyse aggression-based dominance hierarchies formed by worker ants in Diacamma sp. as large directed networks. We show that the observed dominance networks are perfect or approximate directed acyclic graphs, which are consistent with perfect linear hierarchy. The observed networks are also sparse and random but significantly different from networks generated through thinning of the perfect linear tournament (i.e. all individuals are linearly ranked and dominance relationship exists between every pair of individuals). These results pertain to global structure of the networks, which contrasts with the previous studies inspecting frequencies of different types of triads. In addition, the distribution of the out-degree (i.e. number of workers that the focal worker attacks), not in-degree (i.e. number of workers that attack the focal worker), of each observed network is right-skewed. Those having excessively large out-degrees are located near the top, but not the top, of the hierarchy. We also discuss evolutionary implications of the discovered properties of dominance networks. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  4. Individuals and the variation needed for high species diversity in forest trees

    Science.gov (United States)

    James S. Clark

    2010-01-01

    In the past, explanations for high species diversity have been sought at the species level. Theory shows that coexistence requires substantial differences between species, but species-level data rarely provide evidence for such differences. Using data from forests in the southeastern United States, I show here that variation evident at the individual level provides for...

  5. Alien dominance of the parasitoid wasp community along an elevation gradient on Hawai'i Island

    Science.gov (United States)

    Peck, R.W.; Banko, P.C.; Schwarzfeld, M.; Euaparadorn, M.; Brinck, K.W.

    2008-01-01

    Through intentional and accidental introduction, more than 100 species of alien Ichneumonidae and Braconidae (Hymenoptera) have become established in the Hawaiian Islands. The extent to which these parasitoid wasps have penetrated native wet forests was investigated over a 1,765 m elevation gradient on windward Hawai'i Island. For >1 year, malaise traps were used to continuously monitor parasitoid abundance and species richness in nine sites over three elevations. A total of 18,996 individuals from 16 subfamilies were collected. Overall, the fauna was dominated by aliens, with 44 of 58 species foreign to the Hawaiian Islands. Ichneumonidae was dominant over Braconidae in terms of both diversity and abundance, comprising 67.5% of individuals and 69.0% of species collected. Parasitoid abundance and species richness varied significantly with elevation: abundance was greater at mid and high elevations compared to low elevation while species richness increased with increasing elevation, with all three elevations differing significantly from each other. Nine species purposely introduced to control pest insects were found, but one braconid, Meteorus laphygmae, comprised 98.0% of this assemblage, or 28.3% of the entire fauna. Endemic species, primarily within the genera Spolas and Enicospilus, were collected almost exclusively at mid- and high-elevation sites, where they made up 22.1% and 36.0% of the total catch, respectively. Overall, 75.9% of species and 96.0% of individuals are inferred to parasitize Lepidoptera larvae and pupae. Our results support previous data indicating that alien parasitoids have deeply penetrated native forest habitats and may have substantial impacts on Hawaiian ecosystems. ?? 2008 Springer Science+Business Media B.V.

  6. Primate social attention: Species differences and effects of individual experience in humans, great apes, and macaques.

    Directory of Open Access Journals (Sweden)

    Fumihiro Kano

    Full Text Available When viewing social scenes, humans and nonhuman primates focus on particular features, such as the models' eyes, mouth, and action targets. Previous studies reported that such viewing patterns vary significantly across individuals in humans, and also across closely-related primate species. However, the nature of these individual and species differences remains unclear, particularly among nonhuman primates. In large samples of human and nonhuman primates, we examined species differences and the effects of experience on patterns of gaze toward social movies. Experiment 1 examined the species differences across rhesus macaques, nonhuman apes (bonobos, chimpanzees, and orangutans, and humans while they viewed movies of various animals' species-typical behaviors. We found that each species had distinct viewing patterns of the models' faces, eyes, mouths, and action targets. Experiment 2 tested the effect of individuals' experience on chimpanzee and human viewing patterns. We presented movies depicting natural behaviors of chimpanzees to three groups of chimpanzees (individuals from a zoo, a sanctuary, and a research institute differing in their early social and physical experiences. We also presented the same movies to human adults and children differing in their expertise with chimpanzees (experts vs. novices or movie-viewing generally (adults vs. preschoolers. Individuals varied within each species in their patterns of gaze toward models' faces, eyes, mouths, and action targets depending on their unique individual experiences. We thus found that the viewing patterns for social stimuli are both individual- and species-specific in these closely-related primates. Such individual/species-specificities are likely related to both individual experience and species-typical temperament, suggesting that primate individuals acquire their unique attentional biases through both ontogeny and evolution. Such unique attentional biases may help them learn

  7. Primate social attention: Species differences and effects of individual experience in humans, great apes, and macaques.

    Science.gov (United States)

    Kano, Fumihiro; Shepherd, Stephen V; Hirata, Satoshi; Call, Josep

    2018-01-01

    When viewing social scenes, humans and nonhuman primates focus on particular features, such as the models' eyes, mouth, and action targets. Previous studies reported that such viewing patterns vary significantly across individuals in humans, and also across closely-related primate species. However, the nature of these individual and species differences remains unclear, particularly among nonhuman primates. In large samples of human and nonhuman primates, we examined species differences and the effects of experience on patterns of gaze toward social movies. Experiment 1 examined the species differences across rhesus macaques, nonhuman apes (bonobos, chimpanzees, and orangutans), and humans while they viewed movies of various animals' species-typical behaviors. We found that each species had distinct viewing patterns of the models' faces, eyes, mouths, and action targets. Experiment 2 tested the effect of individuals' experience on chimpanzee and human viewing patterns. We presented movies depicting natural behaviors of chimpanzees to three groups of chimpanzees (individuals from a zoo, a sanctuary, and a research institute) differing in their early social and physical experiences. We also presented the same movies to human adults and children differing in their expertise with chimpanzees (experts vs. novices) or movie-viewing generally (adults vs. preschoolers). Individuals varied within each species in their patterns of gaze toward models' faces, eyes, mouths, and action targets depending on their unique individual experiences. We thus found that the viewing patterns for social stimuli are both individual- and species-specific in these closely-related primates. Such individual/species-specificities are likely related to both individual experience and species-typical temperament, suggesting that primate individuals acquire their unique attentional biases through both ontogeny and evolution. Such unique attentional biases may help them learn efficiently about their

  8. Hypothalamic digoxin, hemispheric chemical dominance, and creativity.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-04-01

    The human hypothalamus produces an endogenous membrane Na(+)-K+ ATPase inhibitor, digoxin, which regulates neuronal transmission. The digoxin status and neurotransmitter patterns were studied in creative and non-creative individuals, as well as in individuals with differing hemispheric dominance, in order to find out the role of cerebral dominance in this respect. The activity of HMG CoA reductase and serum levels of digoxin, magnesium, tryptophan catabolites, and tyrosine catabolites were measured in creative/non-creative individuals, and in individuals with differing hemispheric dominance. In creative individuals there was increased digoxin synthesis, decreased membrane Na(+)-K+ ATPase activity, increased tryptophan catabolites (serotonin, quinolinic acid, and nicotine), and decreased tyrosine catabolites (dopamine, noradrenaline, and morphine). The pattern in creative individuals correlated with right hemispheric dominance. In non-creative individuals there was decreased digoxin synthesis, increased membrane Na(+)-K+ ATPase activity, decreased tryptophan catabolites (serotonin, quinolinic acid, and nicotine), and increased tyrosine catabolites (dopamine, noradrenaline, and morphine). This pattern in non-creative individuals correlated with that obtained in left hemispheric chemical dominance. Hemispheric chemical dominance and hypothalamic digoxin could regulate the predisposition to creative tendency.

  9. Few vertebrate species dominate the Borrelia burgdorferi s.l. life cycle

    Science.gov (United States)

    Hofmeester, T. R.; Coipan, E. C.; van Wieren, S. E.; Prins, H. H. T.; Takken, W.; Sprong, H.

    2016-04-01

    Background. In the northern hemisphere, ticks of the Ixodidae family are vectors of diseases such as Lyme borreliosis, Rocky Mountain spotted fever and tick-borne encephalitis. Most of these ticks are generalists and have a three-host life cycle for which they are dependent on three different hosts for their blood meal. Finding out which host species contribute most in maintaining ticks and the pathogens they transmit, is imperative in understanding the drivers behind the dynamics of a disease. Methods. We performed a systematic review to identify the most important vertebrate host species for Ixodes ricinus and Borrelia burgdorferi s.l. as a well-studied model system for tick-borne diseases. We analyzed data from 66 publications and quantified the relative contribution for 15 host species. Review results. We found a positive correlation between host body mass and tick burdens for the different stages of I. ricinus. We show that nymphal burdens of host species are positively correlated with infection prevalence with B. burgdorferi s.l., which is again positively correlated with the realized reservoir competence of a host species for B. burgdorferi s.l. Our quantification method suggests that only a few host species, which are amongst the most widespread species in the environment (rodents, thrushes and deer), feed the majority of I. ricinus individuals and that rodents infect the majority of I. ricinus larvae with B. burgdorferi s.l. Discussion. We argue that small mammal-transmitted Borrelia spp. are maintained due to the high density of their reservoir hosts, while bird-transmitted Borrelia spp. are maintained due to the high infection prevalence of their reservoir hosts. Our findings suggest that Ixodes ricinus and Borrelia burgdorferi s.l. populations are maintained by a few widespread host species. The increase in distribution and abundance of these species, could be the cause for the increase in Lyme borreliosis incidence in Europe in recent decades.

  10. Individual species affect plant traits structure in their surroundings: evidence of functional mechanisms of assembly.

    Science.gov (United States)

    Chacón-Labella, Julia; de la Cruz, Marcelino; Pescador, David S; Escudero, Adrián

    2016-04-01

    Evaluating community assembly through the use of functional traits is a promising tool for testing predictions arising from Niche and Coexistence theories. Although interactions among neighboring species and their inter-specific differences are known drivers of coexistence with a strong spatial signal, assessing the role of individual species on the functional structure of the community at different spatial scales remains a challenge. Here, we ask whether individual species exert a measurable effect on the spatial organization of different functional traits in local assemblages. We first propose and compute two functions that describe different aspects of functional trait organization around individual species at multiple scales: individual weighted mean area relationship and individual functional diversity area relationship. Secondly, we develop a conceptual model on the relationship and simultaneous variation of these two metrics, providing five alternative scenarios in response to the ability of some target species to modify its neighbor environment and the possible assembly mechanisms involved. Our results show that some species influence the spatial structure of specific functional traits, but their effects were always restricted to the finest spatial scales. In the basis of our conceptual model, the observed patterns point to two main mechanisms driving the functional structure of the community at the fine scale, "biotic" filtering meditated by individual species and resource partitioning driven by indirect facilitation rather than by competitive mechanisms.

  11. Hypothalamic digoxin, hemispheric chemical dominance, and spirituality.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-03-01

    The isoprenoid pathway was assessed in atheistic and spiritually inclined individuals. The pathway was also assessed in individuals with differing hemispheric dominance to assess whether hemispheric dominance has a correlation with spiritual and atheistic tendency. HMG CoA reductase activity, serum digoxin, RBC membrane Na(+)-K+ ATPase activity, serum magnesium, and tyrosine/tryptophan catabolic patterns were assessed in spiritual/atheistic individuals and in those differing hemispheric dominance. In spiritually-inclined individuals, there was increased digoxin synthesis, decreased membrane Na(+)-K+ ATPase activity, increased tryptophan catabolites (serotonin, quinolinic acid, and nicotine), and decreased tyrosine catabolites (dopamine, noradrenaline, and morphine). The pattern in spiritually-inclined individuals correlated with right hemispheric chemical dominance. In atheistic individuals there was decreased digoxin synthesis, increased membrane Na(+)-K+ ATPase activity, decreased tryptophan catabolities (serotonin, quinolinic acid, and nicotine), and increased tyrosine catabolites (dopamine, noradrenaline, and morphine). This pattern in atheistic individuals correlated with that obtained in left hemispheric chemical dominance. Hemispheric chemical dominance and hypothalamic digoxin could regulate the predisposition to spirituality or atheism.

  12. A phylogenetic perspective on the individual species-area relationship in temperate and tropical tree communities.

    Science.gov (United States)

    Yang, Jie; Swenson, Nathan G; Cao, Min; Chuyong, George B; Ewango, Corneille E N; Howe, Robert; Kenfack, David; Thomas, Duncan; Wolf, Amy; Lin, Luxiang

    2013-01-01

    Ecologists have historically used species-area relationships (SARs) as a tool to understand the spatial distribution of species. Recent work has extended SARs to focus on individual-level distributions to generate individual species area relationships (ISARs). The ISAR approach quantifies whether individuals of a species tend have more or less species richness surrounding them than expected by chance. By identifying richness 'accumulators' and 'repellers', respectively, the ISAR approach has been used to infer the relative importance of abiotic and biotic interactions and neutrality. A clear limitation of the SAR and ISAR approaches is that all species are treated as evolutionarily independent and that a large amount of work has now shown that local tree neighborhoods exhibit non-random phylogenetic structure given the species richness. Here, we use nine tropical and temperate forest dynamics plots to ask: (i) do ISARs change predictably across latitude?; (ii) is the phylogenetic diversity in the neighborhood of species accumulators and repellers higher or lower than that expected given the observed species richness?; and (iii) do species accumulators, repellers distributed non-randomly on the community phylogenetic tree? The results indicate no clear trend in ISARs from the temperate zone to the tropics and that the phylogenetic diversity surrounding the individuals of species is generally only non-random on very local scales. Interestingly the distribution of species accumulators and repellers was non-random on the community phylogenies suggesting the presence of phylogenetic signal in the ISAR across latitude.

  13. Lidar-based individual tree species classification using convolutional neural network

    Science.gov (United States)

    Mizoguchi, Tomohiro; Ishii, Akira; Nakamura, Hiroyuki; Inoue, Tsuyoshi; Takamatsu, Hisashi

    2017-06-01

    Terrestrial lidar is commonly used for detailed documentation in the field of forest inventory investigation. Recent improvements of point cloud processing techniques enabled efficient and precise computation of an individual tree shape parameters, such as breast-height diameter, height, and volume. However, tree species are manually specified by skilled workers to date. Previous works for automatic tree species classification mainly focused on aerial or satellite images, and few works have been reported for classification techniques using ground-based sensor data. Several candidate sensors can be considered for classification, such as RGB or multi/hyper spectral cameras. Above all candidates, we use terrestrial lidar because it can obtain high resolution point cloud in the dark forest. We selected bark texture for the classification criteria, since they clearly represent unique characteristics of each tree and do not change their appearance under seasonable variation and aged deterioration. In this paper, we propose a new method for automatic individual tree species classification based on terrestrial lidar using Convolutional Neural Network (CNN). The key component is the creation step of a depth image which well describe the characteristics of each species from a point cloud. We focus on Japanese cedar and cypress which cover the large part of domestic forest. Our experimental results demonstrate the effectiveness of our proposed method.

  14. Who will become dominant? Investigating the roles of individual behaviour, body size, and environmental predictability in brown trout fry hierarchies

    Directory of Open Access Journals (Sweden)

    Näslund Joacim

    2018-02-01

    Full Text Available This paper presents a study investigating performance of brown trout fry, with different behavioural characteristics, in environments differing in food predictability. Based on previous experimental findings, we hypothesised that more active individuals would be favoured by a predictable environment, as compared to an unpredictable environment, as a consequence of being more aggressive and likely to dominate the best feeding stations. This hypothesis was not supported, as more active individuals instead tended to perform better, in terms of growth and survival, in unpredictable environments. However, this effect may stem from initial size differences, as more active fish also tended to be larger. In predictable environments, no trends between activity (or size and performance were detected. Dominant individuals could be identified based on lighter body colouration in 9 out of 10 rearing tanks, but dominance appeared not to be related to activity score. The results highlight a potential advantage of more active and/or larger fry in unpredictable environments, while performance in predictable environments is likely depending on other phenotypic characteristics. Our general experimental approach can be useful for further developments in the investigation of performance of different ethotypes of brown trout fry.

  15. Small-scale shifting mosaics of two dominant grassland species: the possible role of soil-borne pathogens.

    Science.gov (United States)

    Olff, H; Hoorens, B; de Goede, R G M; van der Putten, W H; Gleichman, J M

    2000-10-01

    We analyzed the dynamics of dominant plant species in a grazed grassland over 17 years, and investigated whether local shifts in these dominant species, leading to vegetation mosaics, could be attributed to interactions between plants and soil-borne pathogens. We found that Festuca rubra and Carex arenaria locally alternated in abundance, with different sites close together behaving out of phase, resulting in a shifting mosaic. The net effect of killing all soil biota on the growth of these two species was investigated in a greenhouse experiment using gamma radiation, controlling for possible effects of sterilization on soil chemistry. Both plant species showed a strong net positive response to soil sterilization, indicating that pathogens (e.g., nematodes, pathogenic fungi) outweighed the effect of mutualists (e.g., mycorrhizae). This positive growth response towards soil sterilization appeared not be due to effects of sterilization on soil chemistry. Growth of Carex was strongly reduced by soil-borne pathogens (86% reduction relative to its growth on sterilized soil) on soil from a site where this species decreased during the last decade (and Festuca increased), while it was reduced much less (50%) on soil from a nearby site where it increased in abundance during the last decade. Similarly, Festuca was reduced more (67%) on soil from the site where it decreased (and Carex increased) than on soil from the site where it increased (55%, the site where Carex decreased). Plant-feeding nematodes showed high small-scale variation in densities, and we related this variation to the observed growth reductions in both plant species. Carex growth on unsterilized soil was significantly more reduced at higher densities of plant-feeding nematodes, while the growth reduction in Festuca was independent of plant-feeding nematode densities. At high plant-feeding nematode densities, growth of Carex was reduced more than Festuca, while at low nematode densities the opposite was found

  16. Effects of elevated CO₂, warming and precipitation change on plant growth, photosynthesis and peroxidation in dominant species from North China grassland.

    Science.gov (United States)

    Xu, Zhenzhu; Shimizu, Hideyuki; Ito, Shoko; Yagasaki, Yasumi; Zou, Chunjing; Zhou, Guangsheng; Zheng, Yuanrun

    2014-02-01

    Warming, watering and elevated atmospheric CO₂-concentration effects have been extensively studied separately; however, their combined impact on plants is not well understood. In the current research, we examined plant growth and physiological responses of three dominant species from the Eurasian Steppe with different functional traits to a combination of elevated CO₂, high temperature, and four simulated precipitation patterns. Elevated CO₂ stimulated plant growth by 10.8-41.7 % for a C₃ leguminous shrub, Caragana microphylla, and by 33.2-52.3 % for a C₃ grass, Stipa grandis, across all temperature and watering treatments. Elevated CO₂, however, did not affect plant biomass of a C₄ grass, Cleistogenes squarrosa, under normal or increased precipitation, whereas a 20.0-69.7 % stimulation of growth occurred with elevated CO₂ under drought conditions. Plant growth was enhanced in the C₃ shrub and the C₄ grass by warming under normal precipitation, but declined drastically with severe drought. The effects of elevated CO₂ on leaf traits, biomass allocation and photosynthetic potential were remarkably species-dependent. Suppression of photosynthetic activity, and enhancement of cell peroxidation by a combination of warming and severe drought, were partly alleviated by elevated CO₂. The relationships between plant functional traits and physiological activities and their responses to climate change were discussed. The present results suggested that the response to CO₂ enrichment may strongly depend on the response of specific species under varying patterns of precipitation, with or without warming, highlighting that individual species and multifactor dependencies must be considered in a projection of terrestrial ecosystem response to climatic change.

  17. Advanced engine management of individual cylinders for control of exhaust species

    Science.gov (United States)

    Graves, Ronald L [Knoxville, TN; West, Brian H [Knoxville, TN; Huff, Shean P [Knoxville, TN; Parks, II, James E

    2008-12-30

    A method and system controls engine-out exhaust species of a combustion engine having a plurality of cylinders. The method typically includes various combinations of steps such as controlling combustion parameters in individual cylinders, grouping the individual cylinders into a lean set and a rich set of one or more cylinders, combusting the lean set in a lean combustion parameter condition having a lean air:fuel equivalence ratio, combusting the rich set in a rich combustion parameter condition having a rich air:fuel equivalence ratio, and adjusting the lean set and the rich set of one or more cylinders to generate net-lean combustion. The exhaust species may have elevated concentrations of hydrogen and oxygen.

  18. Individual-based ant-plant networks: diurnal-nocturnal structure and species-area relationship.

    Directory of Open Access Journals (Sweden)

    Wesley Dáttilo

    Full Text Available Despite the importance and increasing knowledge of ecological networks, sampling effort and intrapopulation variation has been widely overlooked. Using continuous daily sampling of ants visiting three plant species in the Brazilian Neotropical savanna, we evaluated for the first time the topological structure over 24 h and species-area relationships (based on the number of extrafloral nectaries available in individual-based ant-plant networks. We observed that diurnal and nocturnal ant-plant networks exhibited the same pattern of interactions: a nested and non-modular pattern and an average level of network specialization. Despite the high similarity in the ants' composition between the two collection periods, ant species found in the central core of highly interacting species totally changed between diurnal and nocturnal sampling for all plant species. In other words, this "night-turnover" suggests that the ecological dynamics of these ant-plant interactions can be temporally partitioned (day and night at a small spatial scale. Thus, it is possible that in some cases processes shaping mutualistic networks formed by protective ants and plants may be underestimated by diurnal sampling alone. Moreover, we did not observe any effect of the number of extrafloral nectaries on ant richness and their foraging on such plants in any of the studied ant-plant networks. We hypothesize that competitively superior ants could monopolize individual plants and allow the coexistence of only a few other ant species, however, other alternative hypotheses are also discussed. Thus, sampling period and species-area relationship produces basic information that increases our confidence in how individual-based ant-plant networks are structured, and the need to consider nocturnal records in ant-plant network sampling design so as to decrease inappropriate inferences.

  19. Two common species dominate the species-rich Euglossine bee fauna of an Atlantic Rainforest remnant in Pernambuco, Brazil.

    Science.gov (United States)

    Oliveira, R; Pinto, C E; Schlindwein, C

    2015-11-01

    Nowadays, the northern part of the Atlantic Rainforest of Brazil is largely destroyed and forest remnants rarely exceed 100 ha. In a 118 ha forest fragment within a state nature reserve of Pernambuco (Reserva Ecológica Gurjaú), we surveyed the orchid bee fauna (Apidae, Euglossini) using eight different scent baits to attract males. Once a month during one year, the bees were actively collected with entomological nets, from November 2002 to October 2003 by two collectors. We collected 2,908 orchid bee males belonging to 23 species, one of the highest richness values of the Northern Atlantic Rainforest. Bees of only two species, Euglossa carolina (50%) and Eulaema nigrita (25%), which occurred throughout the year, accounted for three quarter of the collected individuals. Both species are typical for open or disturbed areas. Rainforest remnants like those of Gurjaú within the predominant sugar cane monocultures in the coastal plains of the northern Atlantic Rainforest play an important role in orchid bee conservation and maintenance of biodiversity.

  20. Ecosystem and Community Responses to Rainfall Manipulations in Shrublands Depends on Dominant Vegetation Cover

    Science.gov (United States)

    Esch, E. H.; Lipson, D.; Kim, J. B.; Cleland, E. E.

    2014-12-01

    Southern California is predicted to face decreasing precipitation with increased interannual variability in the coming century. Native shrublands in this area are increasingly invaded by exotic annual grasses, though invasion dynamics can vary by rainfall scenario, with wet years generally associated with high invasion pressure. Interplay between rainfall and invasion scenarios can influence carbon stocks and community composition. Here we asked how invasion alters ecosystem and community responses in drought versus high rainfall scenarios, as quantified by community identity, biomass production, and the normalized difference vegetation index (NDVI). To do this, we performed a rainfall manipulation experiment with paired plots dominated either by native shrubs or exotic herbaceous species, subjected to treatments of 50%, 100%, or 150% of ambient rainfall. The study site was located in a coastal sage scrub ecosystem, with patches dominated by native shrubs and exotic grasses located in San Diego County, USA. During two growing seasons, we found that native, herbaceous biomass production was significantly affected by rainfall treatment (p<0.05 for both years), though was not affected by dominant community composition. Photosynthetic biomass production of shrub species also varied by treatment (p=0.035). Exotic biomass production showed a significant interaction between dominant community composition and rainfall treatment, and both individual effects (p<0.001 for all). NDVI showed similar results, but also indicated the importance of rainfall timing on overall biomass production between years. Community composition data showed certain species, of both native and exotic identities, segregating by treatment. These results indicate that exotic species are more sensitive to rainfall, and that increased rainfall may promote greater carbon storage in annual dominated communities when compared to shrub dominated communities in high rainfall years, but with drought, this

  1. The response of three dominant Arctic copepod species to elevated CO2 concentrations and water temperatures

    OpenAIRE

    Hildebrandt, Nicole

    2014-01-01

    Ocean acidification (OA) and ocean warming are threatening marine life. Within the framework of the research project BIOACID, this thesis aims to provide a comprehensive overview on the sensitivity of the dominant Arctic calanoid copepod species Calanus finmarchicus, C. glacialis and C. hyperboreus to elevated pCO2 and temperatures. Controlled laboratory experiments have shown that subadult and adult Calanus life stages are rather robust to the direct effects of OA during both active and rest...

  2. Identification of Nematode Fauna in Vineyards of South of Western Azerbaijan and Determination of the Dominant Parasitic Species

    Directory of Open Access Journals (Sweden)

    E. Mohajeri

    2017-12-01

    Full Text Available Introduction: Grapevine belongs to the Vitaceae family that consists of 14 genera and about 700 species. Only in the genus Vitis fruits are edible. Italy is the largest producer of grapes and Iran has the seventh position in the world from this point of view. Western Azarbaijan province comprises a high diversity of crops including wild grapes. Although, some nematodes are free living and antagonists of another soil microfauna, the other are plant parasitic agents. Most of which live in the agricultural soils where they are widely dispersed. Effectiveness of the disease management strategies are affected by the accurate identification of the plant disease causal agents and the nematodal diseases are not the exception from this rule. Therefore, for control of the diseases caused by the nematodes, it is necessary to separate the parasitic nematodes from the suspected contaminated soils and identify them. Although separation and identification of the nematodes are partly time-consuming, it is not very complicated. Some nematodes likeXiphinema, Longidorus and Ditylenchus are cosmopolitan and catastrophic nematodes in vineyards worldwide. So far no study has been performed regarding the plant parasitic nematode in vineyards of the south of Western Azerbaijan. Therefore, in this study as an introduction to the management ofthe vineyard parasitic nematodes, the dominant nematodes of the plant were identified. In the next step, investigation of nematodes bioecology, the interaction of nematodes with the other plant pathogens, their host range and their damages to the host plants would be studied. Materials and Methods: In order to identify the fauna of plant parasitic nematodes in vineyards of the south of Western Azarbaijan, during 2013-2014, 50 soil samples were collected from the rhizosphere of grapevine. The sampling was carried out from the vineyards of five grapevine growing cities including Mahabad, Bookan, Sardasht, Piranshahr and Miyandoab. The

  3. Food source quality and ant dominance hierarchy influence the outcomes of ant-plant interactions in an arid environment

    Science.gov (United States)

    Flores-Flores, Rocío Vianey; Aguirre, Armando; Anjos, Diego V.; Neves, Frederico S.; Campos, Ricardo I.; Dáttilo, Wesley

    2018-02-01

    In this study, we conducted a series of experiments in a population of Vachellia constricta (Fabaceae) in the arid Tehuacan-Cuicatláan valley, Mexico, in order to evaluate if the food source quality and ant dominance hierarchy influence the outcomes of ant-plant interactions. Using an experiment with artificial nectaries, we observed that ants foraging on food sources with higher concentration of sugar are quicker in finding and attacking potential herbivorous insects. More specifically, we found that the same ant species may increase their defence effectiveness according to the quality of food available. These findings indicate that ant effectiveness in plant protection is context-dependent and may vary according to specific individual characteristics of plants. In addition, we showed that competitively superior ant species tend to dominate plants in periods with high nectar activity, emphasizing the role of the dominance hierarchy structuring ant-plant interactions. However, when high sugar food sources were experimentally available ad libitum, the nocturnal and competitively superior ant species, Camponotus atriceps, did not dominate the artificial nectaries during the day possibly due to limitation of its thermal tolerance. Therefore, temporal niche partitioning may be allowing the coexistence of two dominant ant species (Camponotus rubritorax during the day and C. atriceps at night) on V. constricta. Our findings indicate that the quality of the food source, and temporal shifts in ant dominance are key factors which structure the biotic plant defences in an arid environment.

  4. Relations between Spatial Distribution, Social Affiliations and Dominance Hierarchy in a Semi-Free Mandrill Population.

    Science.gov (United States)

    Naud, Alexandre; Chailleux, Eloise; Kestens, Yan; Bret, Céline; Desjardins, Dominic; Petit, Odile; Ngoubangoye, Barthélémy; Sueur, Cédric

    2016-01-01

    Although there exist advantages to group-living in comparison to a solitary lifestyle, costs and gains of group-living may be unequally distributed among group members. Predation risk, vigilance levels and food intake may be unevenly distributed across group spatial geometry and certain within-group spatial positions may be more or less advantageous depending on the spatial distribution of these factors. In species characterized with dominance hierarchy, high-ranking individuals are commonly observed in advantageous spatial position. However, in complex social systems, individuals can develop affiliative relationships that may balance the effect of dominance relationships in individual's spatial distribution. The objective of the present study is to investigate how the group spatial distribution of a semi-free ranging colony of Mandrills relates to its social organization. Using spatial observations in an area surrounding the feeding zone, we tested the three following hypothesis: (1) does dominance hierarchy explain being observed in proximity or far from a food patch? (2) Do affiliative associations also explain being observed in proximity or far from a food patch? (3) Do the differences in rank in the group hierarchy explain being co-observed in proximity of a food patch? Our results showed that high-ranking individuals were more observed in proximity of the feeding zone while low-ranking individuals were more observed at the boundaries of the observation area. Furthermore, we observed that affiliative relationships were also associated with individual spatial distributions and explain more of the total variance of the spatial distribution in comparison with dominance hierarchy. Finally, we found that individuals observed at a same moment in proximity of the feeding zone were more likely to be distant in the hierarchy while controlling for maternal kinship, age and sex similarity. This study brings some elements about how affiliative networks and dominance

  5. Individual dispersal delays in a cooperative breeder: Ecological constraints, the benefits of philopatry and the social queue for dominance.

    Science.gov (United States)

    Nelson-Flower, Martha J; Wiley, Elizabeth M; Flower, Tom P; Ridley, Amanda R

    2018-03-20

    Delayed dispersal is a key step in the evolution of familial animal societies and cooperative breeding. However, no consensus has been reached on the ecological and social circumstances driving delayed dispersal. Here, we test predictions from the ecological constraints and benefits of philopatry hypotheses as well as the recently proposed dual benefits hypothesis to better understand the evolution of group-living and cooperative breeding. Furthermore, we consider how individual social circumstances within groups affect dispersal decisions. We examine 11 years of life-history information on a wild population of cooperatively breeding southern pied babblers Turdoides bicolor. We investigate the effects of ecological conditions, natal-group membership and individual social context on male and female dispersal delays, disperser survival and acquisition of dominance. Female dispersal decisions are generally unconstrained by ecological or social circumstances. In contrast, males disperse in response to relaxed ecological constraints, decreases in nepotistic tolerance or when low social rank in the queue for dominance decreases their likelihood of gaining a dominant breeding position. Early dispersal by end-of-queue males often leads to a head-of-queue subordinate position in a non-natal group, thereby increasing access to dominant breeding positions. However, males and females remaining in natal groups gain benefits of philopatry via increased survival and, for head-of-queue males, very high likelihood of acquisition of a breeding position. Overall, predictions from the dual benefits hypothesis best describe these results, while some predictions from each of the ecological constraints and benefits of philopatry hypotheses were supported. The benefits of living and working together (collective action benefits) in large stable groups are of central importance in shaping dispersal delays in southern pied babbler societies. In addition, position in the subordinate social

  6. The Rules of Aggression: How Genetic, Chemical and Spatial Factors Affect Intercolony Fights in a Dominant Species, the Mediterranean Acrobat Ant Crematogaster scutellaris.

    Directory of Open Access Journals (Sweden)

    Filippo Frizzi

    Full Text Available Nest-mate recognition plays a key role in the biology of ants. Although individuals coming from a foreign nest are, in most cases, promptly rejected, the degree of aggressiveness towards non nest-mates may be highly variable among species and relies on genetic, chemical and environmental factors. We analyzed intraspecific relationships among neighboring colonies of the dominant Mediterranean acrobat ant Crematogaster scutellaris integrating genetic, chemical and behavioral analyses. Colony structure, parental relationships between nests, cuticular hydrocarbons profiles (CHCs and aggressive behavior against non nest-mates were studied in 34 nests located in olive tree trunks. Bayesian clustering analysis of allelic variation at nine species-specific microsatellite DNA markers pooled nests into 14 distinct clusters, each representing a single colony, confirming a polydomous arrangement of nests in this species. A marked genetic separation among colonies was also detected, probably due to long distance dispersion of queens and males during nuptial flights. CHCs profiles varied significantly among colonies and between nests of the same colony. No relationship between CHCs profiles and genetic distances was detected. The level of aggressiveness between colonies was inversely related to chemical and spatial distance, suggesting a 'nasty neighbor' effect. Our findings also suggest that CHCs profiles in C. scutellaris may be linked to external environmental factors rather than genetic relationships.

  7. Primate social attention: Species differences and effects of individual experience in humans, great apes, and macaques

    OpenAIRE

    Kano, Fumihiro; Shepherd, Stephen V.; Hirata, Satoshi; Call, Josep

    2018-01-01

    When viewing social scenes, humans and nonhuman primates focus on particular features, such as the models’ eyes, mouth, and action targets. Previous studies reported that such viewing patterns vary significantly across individuals in humans, and also across closely-related primate species. However, the nature of these individual and species differences remains unclear, particularly among nonhuman primates. In large samples of human and nonhuman primates, we examined species differences and th...

  8. Relations Between Spatial Distribution, Social Affiliations And Dominance Hierarchy In A Semi-Free Mandrill Population

    Directory of Open Access Journals (Sweden)

    Alexandre eNaud

    2016-05-01

    Full Text Available Although there exist advantages to group-living in comparison to a solitary lifestyle, costs and gains of group-living may be unequally distributed among group members. Predation risk, vigilance levels and food intake may be unevenly distributed across group spatial geometry and certain within-group spatial positions may be more or less advantageous depending on the spatial distribution of these factors. In species characterized with dominance hierarchy, high-ranking individuals are commonly observed in advantageous spatial position. However, in complex social systems, individuals can develop affiliative relationships that may balance the effect of dominance relationships in individual’s spatial distribution. The objective of the present study is to investigate how the group spatial distribution of a semi-free ranging colony of Mandrills relates to its social organization. Using spatial observations in an area surrounding the feeding zone, we tested the three following hypothesis: (1 does dominance hierarchy explain being observed in proximity or far from a food patch? (2 Do affiliative associations also explain being observed in proximity or far from a food patch? (3 Do the differences in rank in the group hierarchy explain being co-observed in proximity of a food patch? Our results showed that high-ranking individuals were more observed in proximity of the feeding zone while low-ranking individuals were more observed at the boundaries of the observation area. Furthermore, we observed that affiliative relationships were also associated with individual spatial distributions and explain more of the total variance of the spatial distribution in comparison with dominance hierarchy. Finally, we found that individuals observed at a same moment in proximity of the feeding zone were more likely to be distant in the hierarchy while controlling for maternal kinship, age and sex similarity. This study brings some elements about how affiliative networks

  9. Use of Gifu Anaerobic Medium for culturing 32 dominant species of human gut microbes and its evaluation based on short-chain fatty acids fermentation profiles.

    Science.gov (United States)

    Gotoh, Aina; Nara, Misaki; Sugiyama, Yuta; Sakanaka, Mikiyasu; Yachi, Hiroyuki; Kitakata, Aya; Nakagawa, Akira; Minami, Hiromichi; Okuda, Shujiro; Katoh, Toshihiko; Katayama, Takane; Kurihara, Shin

    2017-10-01

    Recently, a "human gut microbial gene catalogue," which ranks the dominance of microbe genus/species in human fecal samples, was published. Most of the bacteria ranked in the catalog are currently publicly available; however, the growth media recommended by the distributors vary among species, hampering physiological comparisons among the bacteria. To address this problem, we evaluated Gifu anaerobic medium (GAM) as a standard medium. Forty-four publicly available species of the top 56 species listed in the "human gut microbial gene catalogue" were cultured in GAM, and out of these, 32 (72%) were successfully cultured. Short-chain fatty acids from the bacterial culture supernatants were then quantified, and bacterial metabolic pathways were predicted based on in silico genomic sequence analysis. Our system provides a useful platform for assessing growth properties and analyzing metabolites of dominant human gut bacteria grown in GAM and supplemented with compounds of interest.

  10. Prevalence of Candida species in the buccal cavity of diabetic and non-diabetic individuals in and around Pondicherry.

    Science.gov (United States)

    Lydia Rajakumari, M; Saravana Kumari, P

    2016-12-01

    The aim of the present study was to determine the prevalence of Candida in the buccal cavity of diabetic and non-diabetic individuals in and around Pondicherry, India and to analyse the antifungal susceptibility profile of the selected isolates. A total of 400 buccal samples, 200 each from diabetic and non-diabetic healthy individuals were included in the study. Sabouraud's dextrose agar was used for isolation of Candida species. Identification was performed through microscopy, germ tube test, sugar fermentation test, sugar assimilation test and by using Hichrome agar. Distinct and phenotypically representative colonies were selected and subjected to ITS analysis. In vitro antifungal susceptibility testing for the isolated Candida species was performed using E-test. Results revealed that the prevalence of Candida species in diabetic individuals was higher when compared with non-diabetic healthy individuals. The most predominantly isolated species in diabetic and non-diabetic individuals from buccal cavity was Candida albicans. C. tropicalis was predominant among the non-albicans Candida isolated from both diabetic and non-diabetic individuals. Among denture wearers C. glabrata was predominant. In vitro antifungal susceptibility testing shows that ketoconazole, fluconazole and itraconazole were effective against the isolated Candida species. The rate of candidal carriage in diabetic individuals is higher. Different species of Candida are present in the oral cavity of diabetic individuals. There may be a positive correlation between glycemic control and candidal colonization. In vitro antifungal susceptibility testing of Candia species are required for proper management and treatment of candidal infections. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  11. Mechanism Underlying the Spatial Pattern Formation of Dominant Tree Species in a Natural Secondary Forest.

    Directory of Open Access Journals (Sweden)

    Guodong Jia

    Full Text Available Studying the spatial pattern of plant species may provide significant insights into processes and mechanisms that maintain stand stability. To better understand the dynamics of naturally regenerated secondary forests, univariate and bivariate Ripley's L(r functions were employed to evaluate intra-/interspecific relationships of four dominant tree species (Populus davidiana, Betula platyphylla, Larix gmelinii and Acer mono and to distinguish the underlying mechanism of spatial distribution. The results showed that the distribution of soil, water and nutrients was not fragmented but presented clear gradients. An overall aggregated distribution existed at most distances. No correlation was found between the spatial pattern of soil conditions and that of trees. Both positive and negative intra- and interspecific relationships were found between different DBH classes at various distances. Large trees did not show systematic inhibition of the saplings. By contrast, the inhibition intensified as the height differences increased between the compared pairs. Except for Larix, universal inhibition of saplings by upper layer trees occurred among other species, and this reflected the vertical competition for light. Therefore, we believe that competition for light rather than soil nutrients underlies the mechanism driving the formation of stand spatial pattern in the rocky mountainous areas examined.

  12. Contact calls of the northern and southern white rhinoceros allow for individual and species identification.

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    Ivana Cinková

    Full Text Available Inter-individual relationships particularly in socially living mammals often require a well-developed communication system. Vocal and olfactory signals are the most important for the communication of rhinos, however, their vocal communication has been investigated to a very limited extent so far. White rhinos have the most developed social system out of all the rhinoceros species and vocal signals might therefore play an important role in their social interactions. We recorded repetitive contact pant calls from six captive northern white rhinos (Ceratotherium cottoni and 14 captive and free-ranging southern white rhinos (Ceratotherium simum and examined if they transmit information about individual identity, species, social context and age class. Discriminant analyses revealed that a high percentage of the pant calls of both species could be classified to a correct individual. We calculated signature information capacity of pant calls recorded from adult animals in isolation at 3.19 bits for the northern white rhinos and at 3.15 bits for the southern white rhinos, which can potentially allow for a vocal discrimination of nine individuals of both species. We found that pant calls varied by species. Northern white rhinos had longer calls and also differed from the southern white rhinos in several frequency parameters of their calls. We also analysed the pant calls of southern white rhinos for the differences between the age classes and between social contexts in which they were recorded. Our results show that pant calls carry information about individual, species, age class and context. The ability to recognize this information would allow rhinos, in addition to olfactory cues, to communicate with highly increased accuracy. A better understanding of communication of white rhinos has potential practical use in their management and conservation particularly because of the low breeding success of white rhinos in captivity.

  13. Chimpanzees copy dominant and knowledgeable individuals

    DEFF Research Database (Denmark)

    Kendal, Rachel; Hopper, Lydia M.; Whiten, Andrew

    2015-01-01

    Evolutionary theory predicts that natural selection will fashion cognitive biases to guide when, and from whom, individuals acquire social information, but the precise nature of these biases, especially in ecologically valid group contexts, remains unknown. We exposed four captive groups...

  14. fish species and size distribution and abundance in different areas

    African Journals Online (AJOL)

    Larger individuals dominated in deep waters recording a mode at 45.5 cm TL. ... as a result of trophic interactions with introduced species ... sea level. The climate is equatorial with two wet seasons, one between October and. December, the ...

  15. Revisiting the role of individual variability in population persistence and stability.

    Directory of Open Access Journals (Sweden)

    Andrew Morozov

    Full Text Available Populations often exhibit a pronounced degree of individual variability and this can be important when constructing ecological models. In this paper, we revisit the role of inter-individual variability in population persistence and stability under predation pressure. As a case study, we consider interactions between a structured population of zooplankton grazers and their predators. Unlike previous structured population models, which only consider variability of individuals according to the age or body size, we focus on physiological and behavioural structuring. We first experimentally demonstrate a high degree of variation of individual consumption rates in three dominant species of herbivorous copepods (Calanus finmarchicus, Calanus glacialis, Calanus euxinus and show that this disparity implies a pronounced variation in the consumption capacities of individuals. Then we construct a parsimonious predator-prey model which takes into account the intra-population variability of prey individuals according to behavioural traits: effectively, each organism has a 'personality' of its own. Our modelling results show that structuring of prey according to their growth rate and vulnerability to predation can dampen predator-prey cycles and enhance persistence of a species, even if the resource stock for prey is unlimited. The main mechanism of efficient top-down regulation is shown to work by letting the prey population become dominated by less vulnerable individuals when predator densities are high, while the trait distribution recovers when the predator densities are low.

  16. Diversity and aggregation patterns of plant species in a grass community

    Directory of Open Access Journals (Sweden)

    Ran Li

    2014-09-01

    Full Text Available Both composition and aggregation patterns of species in a community are the outcome of community self-organizing. In this paper we conducted analysis on species diversity and aggregation patterns of plant species in a grass community, Zhuhai, China. According to the sampling survey, in total of 47 plant species, belonging to 16 families, were found. Compositae had 10 species (21.3%, seconded by Gramineae (9 species, 19.1%, Leguminosae (6 species, 12.8%, Cyperaceae (4 species, 8.5%, and Malvaceae (3 species, 6.4%. The results revealed that the means of aggregation indices Iδ, I and m*/m were 21.71, 15.71 and 19.89 respectively and thus individuals of most of plant species strongly followed aggregative distribution. Iwao analysis indicated that both individuals of all species and clumps of all individuals of all species followed aggregative distribution. Taylor's power law indicated that individuals of all species followed aggregative distribution and aggregation intensity strengthened as the increase of mean density. We held that the strong aggregation intensity of a species has been resulted from the strong adaptation ability to the environment, the strong interspecific competition ability and the earlier establishment of the species. Fitting goodness of the mean, I, Iδ, m*/m with probability distributions demonstrated that the mean (density, I, Iδ, and m*/m over all species followed Weibull distribution rather than normal distribution. Lophatherum gracile, Paederia scandens (Lour. Merr., Eleusine indica, and Alternanthera philoxeroides (Mart. Griseb. were mostly aggregative, and Oxalis sp., Eleocharis plantagineiformis, Vernonia cinerea (L. Less., and Sapium sebiferum (L. Roxb, were mostly uniform in the spatial distribution. Importance values (IV showed that Cynodon dactylon was the most important species, seconded by Desmodium triflorum (L. DC., Cajanus scarabaeoides (L. Benth., Paspalum scrobiculatum L., and Rhynchelytrum repens. Oxalis

  17. Chemical variation in a dominant tree species: population divergence, selection and genetic stability across environments.

    Directory of Open Access Journals (Sweden)

    Julianne M O'Reilly-Wapstra

    Full Text Available Understanding among and within population genetic variation of ecologically important plant traits provides insight into the potential evolutionary processes affecting those traits. The strength and consistency of selection driving variability in traits would be affected by plasticity in differences among genotypes across environments (G×E. We investigated population divergence, selection and environmental plasticity of foliar plant secondary metabolites (PSMs in a dominant tree species, Eucalyptus globulus. Using two common garden trials we examined variation in PSMs at multiple genetic scales; among 12 populations covering the full geographic range of the species and among up to 60 families within populations. Significant genetic variation in the expression of many PSMs resides both among and within populations of E. globulus with moderate (e.g., sideroxylonal A h(2op = 0.24 to high (e.g., macrocarpal G h(2op = 0.48 narrow sense heritabilities and high coefficients of additive genetic variation estimated for some compounds. A comparison of Qst and Fst estimates suggest that variability in some of these traits may be due to selection. Importantly, there was no genetic by environment interaction in the expression of any of the quantitative chemical traits despite often significant site effects. These results provide evidence that natural selection has contributed to population divergence in PSMs in E. globulus, and identifies the formylated phloroglucinol compounds (particularly sideroxylonal and a dominant oil, 1,8-cineole, as candidates for traits whose genetic architecture has been shaped by divergent selection. Additionally, as the genetic differences in these PSMs that influence community phenotypes is stable across environments, the role of plant genotype in structuring communities is strengthened and these genotypic differences may be relatively stable under global environmental changes.

  18. Variations in Vegetation Structure, Species Dominance and Plant Communities in South of the Eastern Desert-Egypt

    Directory of Open Access Journals (Sweden)

    Fawzy SALAMA

    2014-03-01

    Full Text Available For two successive years, the floristic diversity and vegetation composition in the southern part of the Eastern Desert ofEgypt were investigated through four transects (3 crossing the Eastern Desert and one along the Red Sea. The data collected from 142 stands covering the study area included the species composition, functional groups, chorology and occurrences (Qvalues. A total of 94 plant species belonging to 33 different families were recorded, with Asteracea, Zygophyllaceae, Fabaceae,Poaceae, Chenopodiaceae and Brassicaceae as the largest families. Shrubs represented the largest functional group (39.4%, while perennial herbs represented the smallest ones (12.8%. Species occurrence (Q-value revealed that Zilla spinosa, Acacia tortilis subsp raddiana, Morettia philaeana, Caroxylon imbricatum, Zygophyllum coccineum and Citrullus colocynthis had wide ecological range of distribution (dominant species, Q-values 0.2. Saharo-Arabian chorotype was highly represented (72.6 % in the flora of this area, eventually as mono, bi or pluriregional. Classification of the data set yielded 7 vegetation groups included: (A Zilla spinosa-Morettia philaeana, (B1 Zilla spinosa-Citrullus colocynthis-Morettia philaeana, (B2 Zilla spinosa, (C1Zygophyllum album-Tamarix nilotica, (C2 Zygophyllum coccineum-Tamarix nilotica, (D1 Zilla spinosa-Zygophyllum coccineum and (D2 Zilla spinosa-Acacia tortilis subsp. raddiana-Tamarix aphylla-Balanites aegyptiaca. Certain vegetation groups were assigned to one or more transects. Detrended Correspondence Analysis (DCA revealed that electrical conductivity, sodium, potassium, calcium, magnesium, chlorides, moisture content, sulphates, pH, organic matter and gravel were the soil variables that affect the species distribution in this study.

  19. Environmental species sorting dominates forest-bird community assembly across scales

    DEFF Research Database (Denmark)

    Özkan, Korhan; Svenning, J.-C.; Jeppesen, Erik

    2013-01-01

    species richness and composition within the metacommunity. Second, we analysed species' abundance–occupancy relationship across the metacommunity and used null models to assess whether occupancy is determined by species' environmental niches. Third, we used generalized linear models to test for links...... between species' metacommunity-wide occupancy and their broader WP regional populations and assessed whether these links are consistent with environmental species sorting. There was strong environmental control on local species richness and composition patterns within the metacommunity, but non......-environmental spatial factors had also an important joint role. Null model analyses on randomized communities showed that species' occupancy across the metacommunity was strongly determined by species' environmental niches, with occupancy being related to niche position marginality. Species' metacommunity...

  20. Artificial marine habitats favour a single fish species on a long-term scale: the dominance of Boops boops around off-shore fish cages

    Directory of Open Access Journals (Sweden)

    Rodrigo Riera

    2014-12-01

    Full Text Available Off-shore fish cages are new artificial habitats that can affect pelagic fish assemblages and constitute an important food source for wild fish assemblages. This aggregation has noticeable ecological consequences in cage areas in impoverished ecosystems such as those in the Canary archipelago (NE Atlantic Ocean. However, this new habitat could be dominated by a single species, reducing its positive ecological effects. Wild fish assemblages associated with an off-shore fish lease on the northeastern coast of Tenerife (Canary Islands were sampled for six years. Fish assemblage structure beneath fish cages and at controls ( > 500 m from cages differed significantly between locations, with 13 times greater abundance at cage locations. These differences were mainly explained by the dominance of bogue (Boops boops around fish cages. This trend was consistent in the long-term throughout the study period (2004-2009, affecting local fisheries. The presence of fish cages significantly altered wild fish assemblages in the study area, enhancing mainly biomass and abundance of one species, bogue, and causing shifts in species composition.

  1. Hypothalamic digoxin, hemispheric chemical dominance, and sleep.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-04-01

    The isoprenoid path way produces endogenous digoxin, a substance that can regulate neurotransmitter and amino acid transport. Digoxin synthesis and neurotransmitter patterns were assessed in individuals with chronic insomnia. The patterns were compared in those with right hemispheric and left hemispheric dominance. The activity of HMG GoA reductase and serum levels of digoxin, magnesium, tryptophan catabolites, and tyrosine catabolites were measured in individuals with chronic insomnia and in individuals with differing hemispheric dominance. Digoxin synthesis was increased with upregulated tryptophan catabolism (increased levels of serotonin, strychnine, and nicotine), and downregulated tyrosine catabolism (decreased levels of dopamine, noradrenaline, and morphine) in those with chronic insomnia and right hemispheric chemical dominance. Digoxin synthesis was reduced with downregulated tryptophan catabolism (decreased levels of serotonin, strychnine, and nicotine) and upregulated tyrosine catabolism (increased levels of dopamine, noradrenaline, and morphine) in those with normal sleep patterns and left hemispheric chemical dominance. Hypothalamic digoxin plays a central role in the regulation of sleep behavior. Hemispheric chemical dominance in relation to digoxin status is also crucial.

  2. The genetics of hybrid male sterility between the allopatric species pair Drosophila persimilis and D. pseudoobscura bogotana: dominant sterility alleles in collinear autosomal regions.

    Science.gov (United States)

    Chang, Audrey S; Noor, Mohamed A F

    2007-05-01

    F(1) hybrid male sterility is thought to result from interactions between loci on the X chromosome and dominant-acting loci on the autosomes. While X-linked loci that contribute to hybrid male sterility have been precisely localized in many animal taxa, their dominant autosomal interactors have been more difficult to localize precisely and/or have been shown to be of relatively smaller effect. Here, we identified and mapped at least four dominant autosomal factors contributing to hybrid male sterility in the allopatric species pair Drosophila persimilis and D. pseudoobscura bogotana. Using these results, we tested predictions of reduced recombination models of speciation. Consistent with these models, three of the four QTL associated with hybrid male sterility occur in collinear (uninverted) regions of these genomes. Furthermore, these QTL do not contribute significantly to hybrid male sterility in crosses between the sympatric species D. persimilis and D. pseudoobscura pseudoobscura. The autosomal loci identified in this study provide the basis for introgression mapping and, ultimately, for molecular cloning of interacting genes that contribute to F(1) hybrid sterility.

  3. The straight-chain lipid biomarker composition of plant species responsible for the dominant biomass production along two altitudinal transects in the Ecuadorian Andes

    Energy Technology Data Exchange (ETDEWEB)

    Jansen, Boris; Nierop, Klaas G.J.; Verstraten, Jacobus M.; Cleef, Antoine M. [Amsterdam Univ., Center for Geo-ecological Research (ICG), Amsterdam (Netherlands); Hageman, Jos A. [Amsterdam Univ., Swammerdam Inst. for Life Sciences (SILS), Amsterdam (Netherlands)

    2006-11-15

    For a detailed reconstruction of historic upper forest line (UFL) positions, new proxies in addition to traditional pollen and vegetation analyses are needed. If the straight-chain lipid composition in plant leaves and roots is specific enough to allow distinction, their records in soils and peat bogs might be used for this purpose. We tested for such distinctiveness by analyzing the n-alkane, n-alcohol, n-aldehyde and wax ester composition in lipid extracts from the leaves and roots of the 19 plant species responsible for the dominant biomass input into soils and peat bogs along two altitudinal transects in the Ecuadorian Andes. We found the combined n-alkane and n-alcohol composition of the leaves of the studied plants to be unique enough in theory to allow for a distinction of the various plant species. The extractable straight-chain lipid concentrations in the roots were generally much lower than in the leaves of the same species, and were in many cases less specific. The n-fatty acids, n-aldehydes and wax ester compositions in leaves as well as roots appeared to be less suited as biomarkers, due to a lower specificity of the n-fatty acids and the absence of the n-aldehydes and wax ester from a significant number of plant species. Furthermore, using cluster analysis we found the combination of n-alkanes and n-alcohols from leaves to give the most meaningful clustering from the point of view of an UFL reconstruction, with all but one paramo grassland species and all but one peat bog species clustering separately from forest species. In addition, a large C{sub 31} /C{sub 27} n-alkane ratio as well as a large C{sub 26} /C{sub 30} n-alcohol ratio were found to be indicative of paramo vegetation (grasses). Both clustering and ratios can help reconstruct past UFL positions if discerning individual species from soil or peat records proves unfeasible. The preservation of the straight-chain lipid signal was tested in soil and peat samples from the study area predating

  4. [Species-area and species-abundance relationships of arthropod community in various vegetation restoration areas in Zhifanggou watershed, Shaanxi province of Northwest China].

    Science.gov (United States)

    Zhang, Feng; Hong, Bo; Li, Ying-Mei; Chen, Zhi-Jie; Zhang, Shu-Lian; Zhao, Hui-Yan

    2013-02-01

    Taking the Zhifanggou watershed in Ansai, Shaanxi Province of Northwest China as a study unit, an investigation on the arthropods in 8 forest stands was conducted from 2006 to 2008, with the species-area and species-abundance relationships of the arthropods in these stands analyzed by various mathematical models. In these forest stands, the species-area relationship of the arthropods accorded with the formula S= CAm With the increase of investigation area, the species number approached to a constant, and the corresponding smallest investigation area was in the order of natural bush > natural forest > Populus davidiana+Robinia pseudoacacia forest > Hippaphae rhamnoides +Caragana mocrophylla forest> Periploca sepium forest > Hippaphae rhamnoides forest > Robinia pseudoacacia forest > Caragana mocrophylla forest, indicating that the more complex the stands, the larger the minimum area needed to be investigated. Based on sampling investigation, the species-abundance models of the arthropods in various stands were established. Lognormal distribution model (LN) was most suitable to fit the arthropod community in natural recovery stands, suggesting that in the arthropod community, there were more species with medial individual amount and fewer abundant species and rare species, and no obvious dominant species. LogCauchy distribution model (LC) was most suitable to fit the arthropod community in mixed and pure stands. As compared with natural recovery stand, mixed and pure stands had more abundant and rare species, and more dominant species.

  5. Social dominance, values and ideological positioning in college students

    OpenAIRE

    Elena Zubieta; Gisela Delfino; Omar Fernández

    2015-01-01

    Social Dominance Theory (Sidanius & Pratto, 1999) stress that systematic inter group discrimination is related to social ideologies that contribute to coordinate institutions and individuals behaviors. The acceptance of inequity legitimating ideologies is partially determined for individuals general desire of group based domination. This desire is captured by Social Orientation Domination construct -SDO. Pursuing the objective of exploring SDO levels and its relationship with variables su...

  6. Environmental species sorting dominates forest-bird community assembly across scales.

    Science.gov (United States)

    Özkan, Korhan; Svenning, Jens-Christian; Jeppesen, Erik

    2013-01-01

    Environmental species sorting and dispersal are seen as key factors in community assembly, but their relative importance and scale dependence remain uncertain, as the extent to which communities are consistently assembled throughout their biomes. To address these issues, we analysed bird metacommunity structure in a 1200-km(2) forested landscape (Istranca Forests) in Turkish Thrace at the margin of the Western Palaearctic (WP) temperate-forest biome. First, we used spatial regressions and Mantel tests to assess the relative importance of environmental and spatial factors as drivers of local species richness and composition within the metacommunity. Second, we analysed species' abundance-occupancy relationship across the metacommunity and used null models to assess whether occupancy is determined by species' environmental niches. Third, we used generalized linear models to test for links between species' metacommunity-wide occupancy and their broader WP regional populations and assessed whether these links are consistent with environmental species sorting. There was strong environmental control on local species richness and composition patterns within the metacommunity, but non-environmental spatial factors had also an important joint role. Null model analyses on randomized communities showed that species' occupancy across the metacommunity was strongly determined by species' environmental niches, with occupancy being related to niche position marginality. Species' metacommunity-wide occupancy correlated with their local abundance as well as with their range size and total abundance for the whole WP, suggesting that the same assembly mechanisms act consistently across local to regional scales. A species specialization index that was estimated by bird species' habitat use across France, incorporating both niche position and breadth, was significantly related to species' occupancy and abundance at both metacommunity and WP regional scales. Hence, the same niche

  7. Water-body preferences of dominant calanoid copepod species in ...

    African Journals Online (AJOL)

    The distribution of five dominant calanoid copepods was related to different water masses in the Angola-Benguela Front system. Five water bodies were identified by principal component analysis, on the basis of abiotic parameters such as temperature, salinity, dissolved oxygen, phosphate, silicate, nitrate and nitrite.

  8. [Urbanization mechanisms in bird species: population systems transformations or adaptations at the individual level?].

    Science.gov (United States)

    Fridman, V S; Eremkin, G S; Zakharova-Kubareva, N Iu

    2008-01-01

    The present research deals with urbanization of wild bird and mammal species. Forms and mechanisms of population steadiness in the urban landscape have been examined. The urbanization process turned out to be a directed change of the population system forming de novo in the urbolandscape leading to a sustainable organization peculiar for the particular environment. The population organization of different types in urbolandscape is found to provide its stability under conditions of directed and fast changes accompanied with instability and heterogenous structure of habitats. It is shown that the same type of population organization meets the corresponding demands among different species settling in the urban environment. Its features are "openness" and "flowage" of the groups, far order of settlement levels and other units of population system, constant movements of the individuals between the groups as a respond to the signals of urboenvironment significant changes. The "urban" variant of the population system organization turns out to be opposite to that of the same species in the non-urban habitats. After formation of the urban types by the species and successful developing of the town, the urban population becomes separated from the maternal local population and begins to exist independently in the urban landscape. The variety of adaptation aberrations in ecology, behavior, and mode of life of urban birds is the population system stability function in the urban landscape and is not a results of individual selection. It is shown that the urbanization process of the species goes firstly on the population level being the system structure transformation developed by the species towards the most stable state in the town (city) territory. Only after the appearance of stable urban population, the urban individuals show the rapid growth of different changes in ecology, behavior, mode of life that was traditionally described by naturalists as species adaptation to the

  9. Facial width-to-height ratio relates to dominance style in the genus Macaca

    Directory of Open Access Journals (Sweden)

    Marta Borgi

    2016-03-01

    Full Text Available Background. Physical, visual, chemical, and auditory cues signalling fighting ability have independently evolved in many animal taxa as a means to resolve conflicts without escalating to physical aggression. Facial width-to-height ratio (fWHR, i.e., the relative width to height of the face has been associated with dominance-related phenotypes both in humans and in other primates. In humans, faces with a larger fWHR are perceived as more aggressive. Methods. We examined fWHR variation among 11 species of the genus Macaca. Macaques have been grouped into four distinct categories, from despotic to tolerant, based on their female dominance style. Female dominance style is related to intra- and inter-sexual competition in both males and females and is the result of different evolutionary pressure across species. We used female dominance style as a proxy of intra-/inter-sexual competition to test the occurrence of correlated evolution between competitive regimes and dominance-related phenotypes. fWHR was calculated from 145 2D photographs of male and female adult macaques. Results. We found no phylogenetic signal on the differences in fWHR across species in the two sexes. However, fWHR was greater, in females and males, in species characterised by despotic female dominance style than in tolerant species. Discussion. Our results suggest that dominance-related phenotypes are related to differences in competitive regimes and intensity of inter- and intra-sexual selection across species.

  10. Behavioral Profile Predicts Dominance Status in Mountain Chickadees.

    Science.gov (United States)

    Fox, Rebecca A; Ladage, Lara D; Roth, Timothy C; Pravosudov, Vladimir V

    2009-06-01

    Individual variation in stable behavioral traits may explain variation in ecologically-relevant behaviors such as foraging, dispersal, anti-predator behavior, and dominance. We investigated behavioral variation in mountain chickadees (Poecile gambeli), a North American parid that lives in dominance-structured winter flocks, using two common measures of behavioral profile: exploration of a novel room and novel object exploration. We related those behavioral traits to dominance status in male chickadees following brief, pair-wise encounters. Low-exploring birds (birds that visited less than four locations in the novel room) were significantly more likely to become dominant in brief, pairwise encounters with high-exploring birds (i.e., birds that visited all perching locations within a novel room). On the other hand, there was no relationship between novel object exploration and dominance. Interestingly, novel room exploration was also not correlated with novel object exploration. These results suggest that behavioral profile may predict the social status of group-living individuals. Moreover, our results contradict the idea that novel object exploration and novel room exploration are always interchangeable measures of individuals' sensitivity to environmental novelty.

  11. Bee Fauna and Floral Abundance Within Lawn-Dominated Suburban Yards in Springfield, MA.

    Science.gov (United States)

    Lerman, S B; Milam, J

    2016-09-01

    Private yards comprise a significant component of urban lands, with managed lawns representing the dominant land cover. Lawns blanket > 163,000 km 2 of the United States, and 50% of urban and suburban areas. When not treated with herbicides, lawns have the capacity to support a diversity of spontaneous (e.g., not planted) flowers, with the potential to provide nectar and pollen resources for pollinators such as native bees. In order to determine the extent to which suburban lawns support these important species, we surveyed lawns in 17 suburban yards in Springfield, MA, between May and September 2013 and 2014. Householders participating in the study did not apply chemical pesticides or herbicides to lawns for the duration of the study. We collected 5,331 individual bees, representing 111 species, and 29% of bee species reported for the state. The majority of species were native to North America (94.6%), nested in soil (73%), and solitary (48.6%). Species richness was lower for oligolectic (specialists on a single plant; 9.9%) and parasitic species (12.6%). Abundance percentages for number of individuals were similar. We documented 63 plant species in the lawns, the majority of which were not intentionally planted. The most abundant lawn flowers were dandelion ( Taraxacum officinale ) and clover ( Trifolium sp. ). Nearly 30% of the spontaneous plant species growing in the lawns were native to North America. Our study suggests that the spontaneous lawn flowers could be viewed as supplemental floral resources and support pollinators, thereby enhancing the value of urban green spaces.

  12. Radial growth of two dominant montane conifer tree species in response to climate change in North-Central China.

    Science.gov (United States)

    Jiang, Yuan; Zhang, Wentao; Wang, Mingchang; Kang, Muyi; Dong, Manyu

    2014-01-01

    North-Central China is a region in which the air temperature has clearly increased for several decades. Picea meyeri and Larix principis-rupprechtii are the most dominant co-occurring tree species within the cold coniferous forest belt ranging vertically from 1800 m to 2800 m a.s.l. in this region. Based on a tree-ring analysis of 292 increment cores sampled from 146 trees at different elevations, this study aimed to examine if the radial growth of the two species in response to climate is similar, whether the responses are consistent along altitudinal gradients and which species might be favored in the future driven by the changing climate. The results indicated the following: (1) The two species grew in different rhythms at low and high elevation respectively; (2) Both species displayed inconsistent relationships between radial growth and climate data along altitudinal gradients. The correlation between radial growth and the monthly mean temperature in the spring or summer changed from negative at low elevation into positive at high elevation, whereas those between the radial growth and the total monthly precipitation displayed a change from positive into negative along the elevation gradient. These indicate the different influences of the horizontal climate and vertical mountainous climate on the radial growth of the two species; (3) The species-dependent different response to climate in radial growth appeared mainly in autumn of the previous year. The radial growth of L. principis-rupprechtii displayed negative responses both to temperature and to precipitation in the previous September, October or November, which was not observed in the radial growth of P. meyeri. (4) The radial growth of both species will tend to be increased at high elevation and limited at low elevation, and L. principis-rupprechtii might be more favored in the future, if the temperature keeps rising.

  13. Radial growth of two dominant montane conifer tree species in response to climate change in North-Central China.

    Directory of Open Access Journals (Sweden)

    Yuan Jiang

    Full Text Available North-Central China is a region in which the air temperature has clearly increased for several decades. Picea meyeri and Larix principis-rupprechtii are the most dominant co-occurring tree species within the cold coniferous forest belt ranging vertically from 1800 m to 2800 m a.s.l. in this region. Based on a tree-ring analysis of 292 increment cores sampled from 146 trees at different elevations, this study aimed to examine if the radial growth of the two species in response to climate is similar, whether the responses are consistent along altitudinal gradients and which species might be favored in the future driven by the changing climate. The results indicated the following: (1 The two species grew in different rhythms at low and high elevation respectively; (2 Both species displayed inconsistent relationships between radial growth and climate data along altitudinal gradients. The correlation between radial growth and the monthly mean temperature in the spring or summer changed from negative at low elevation into positive at high elevation, whereas those between the radial growth and the total monthly precipitation displayed a change from positive into negative along the elevation gradient. These indicate the different influences of the horizontal climate and vertical mountainous climate on the radial growth of the two species; (3 The species-dependent different response to climate in radial growth appeared mainly in autumn of the previous year. The radial growth of L. principis-rupprechtii displayed negative responses both to temperature and to precipitation in the previous September, October or November, which was not observed in the radial growth of P. meyeri. (4 The radial growth of both species will tend to be increased at high elevation and limited at low elevation, and L. principis-rupprechtii might be more favored in the future, if the temperature keeps rising.

  14. Oxygen isotopic analyses of individual planktic foraminifera species: Implications for seasonality in the western Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Naidu, P.D.; Niitsuma, N.; Naik, S.S.

    The variation of stable isotopes between individual shells of planktic foraminifera of a given species and size may provide short-term seasonal insight on Paleoceanography. In this context, oxygen isotope analyses of individual Globigerinoides...

  15. Influences of hand dominance on the maintenance of benefits after home-based modified constraint-induced movement therapy in individuals with stroke

    Directory of Open Access Journals (Sweden)

    Renata C. M. Lima

    2014-10-01

    Full Text Available Objective: To investigate the influence of hand dominance on the maintenance of gains after home-based modified constraint-induced movement therapy (mCIMT. Method: Aprevious randomized controlled trial was conducted to examine the addition of trunk restraint to the mCIMT. Twenty-two chronic stroke survivors with mild to moderate motor impairments received individual home-based mCIMT with or without trunk restraints, five times per week, three hours daily over two weeks. In this study, the participants were separated into dominant group, which had their paretic upper limb as dominant before the stroke (n=8, and non-dominant group (n=14 for analyses. The ability to perform unimanual tasks was measured by the Wolf Motor Function Test (WMFT and the Motor Activity Log (MAL, whereas the capacity to perform bimanual tasks was measured using the Bilateral Activity Assessment Scale (BAAS. Results: Analysis revealed significant positive effects on the MAL amount of use and quality of the movement scales, as well as on the BAAS scores after intervention, with no differences between groups. Both groups maintained the bimanual improvements during follow-ups (BAAS-seconds 0.1, 95% CI -10.0 to 10.0, however only the dominant group maintained the unilateral improvements (MAL-amount of use: 1.5, 95% CI 0.7 to 2.3; MAL-quality: 1.3, 95% CI 0.5 to 2.1. Conclusions: Upper limb dominance did not interfere with the acquisition of upper limb skills after mCIMT. However, the participants whose paretic upper limb was dominant demonstrated better abilities to maintain the unilateral gains. The bilateral improvements were maintained, regardless of upper limb dominance.

  16. Hypothalamic digoxin, hemispheric chemical dominance, and the tridosha theory.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-05-01

    Ayurveda, the traditional Indian System of Medicine, deals with the theory of the three tridosha states (both physical and psychological): Vata, Pitta, and Kapha. They are the three major human constitutional types that both depend on psychological and physical characteristics. The Pitta state is described as a critical, discriminative, and rational psychological state of mind, while the Kapha state is described as being dominant for emotional stimuli. The Vata state is an intermediate unstable shifting state. The Pitta types are of average height and built with well developed musculature. The Vata types are thin individuals with low body mass index. The Kapha types are short stocky individuals that tend toward obesity, and who are sedentary. The study assessed the biochemical differences between right hemispheric dominant, bihemispheric dominant, and left hemispheric dominant individuals, and then compared this with the patterns obtained in the Vata, Pitta, and Kapha states. The isoprenoid metabolites (digoxin, dolichol, and ubiquinone), glycoconjugate metabolism, free radical metabolism, and the RBC membrane composition were studied. The hemispheric chemical dominance in various systemic diseases and psychological states was also investigated. The results showed that right hemispheric chemically dominant/Kapha state had elevated digoxin levels, increased free radical production and reduced scavenging, increased tryptophan catabolites and reduced tyrosine catabolites, increased glycoconjugate levels and increased cholesterol: phospholipid ratio of RBC membranes. Left hemispheric chemically dominant/Pitta states had the opposite biochemical patterns. The patterns were normal or intermediate in the bihemispheric chemically dominant/Vata state. This pattern could be correlated with various systemic and neuropsychiatric diseases and personality traits. Right hemispheric chemical dominance/Kapha state represents a hyperdigoxinemic state with membrane sodium

  17. A Clostridium Group IV Species Dominates and Suppresses a Mixed Culture Fermentation by Tolerance to Medium Chain Fatty Acids Products

    Science.gov (United States)

    Andersen, Stephen J.; De Groof, Vicky; Khor, Way Cern; Roume, Hugo; Props, Ruben; Coma, Marta; Rabaey, Korneel

    2017-01-01

    A microbial community is engaged in a complex economy of cooperation and competition for carbon and energy. In engineered systems such as anaerobic digestion and fermentation, these relationships are exploited for conversion of a broad range of substrates into products, such as biogas, ethanol, and carboxylic acids. Medium chain fatty acids (MCFAs), for example, hexanoic acid, are valuable, energy dense microbial fermentation products, however, MCFA tend to exhibit microbial toxicity to a broad range of microorganisms at low concentrations. Here, we operated continuous mixed population MCFA fermentations on biorefinery thin stillage to investigate the community response associated with the production and toxicity of MCFA. In this study, an uncultured species from the Clostridium group IV (related to Clostridium sp. BS-1) became enriched in two independent reactors that produced hexanoic acid (up to 8.1 g L−1), octanoic acid (up to 3.2 g L−1), and trace concentrations of decanoic acid. Decanoic acid is reported here for the first time as a possible product of a Clostridium group IV species. Other significant species in the community, Lactobacillus spp. and Acetobacterium sp., generate intermediates in MCFA production, and their collapse in relative abundance resulted in an overall production decrease. A strong correlation was present between the community composition and both the hexanoic acid concentration (p = 0.026) and total volatile fatty acid concentration (p = 0.003). MCFA suppressed species related to Clostridium sp. CPB-6 and Lactobacillus spp. to a greater extent than others. The proportion of the species related to Clostridium sp. BS-1 over Clostridium sp. CPB-6 had a strong correlation with the concentration of octanoic acid (p = 0.003). The dominance of this species and the increase in MCFA resulted in an overall toxic effect on the mixed community, most significantly on the Lactobacillus spp., which resulted in a decrease in total

  18. Hypothalamic digoxin, hemispheric chemical dominance, and interstitial lung disease.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-10-01

    The isoprenoid pathway produces three key metabolites--endogenous digoxin, dolichol, and ubiquinone. This was assessed in patients with idiopathic pulmonary fibrosis and in individuals of differing hemispheric dominance to find out the role of hemispheric dominance in the pathogenesis of idiopathic pulmonary fibrosis. All 15 cases of interstitial lung disease were right-handed/left hemispheric dominant by the dichotic listening test. The isoprenoidal metabolites--digoxin, dolichol, and ubiquinone, RBC membrane Na(+)-K+ ATPase activity, serum magnesium, tyrosine/tryptophan catabolic patterns, free radical metabolism, glycoconjugate metabolism, and RBC membrane composition--were assessed in idiopathic pulmonary fibrosis as well as in individuals with differing hemispheric dominance. In patients with idiopathic pulmonary fibrosis there was elevated digoxin synthesis, increased dolichol and glycoconjugate levels, and low ubiquinone and elevated free radical levels. There was also an increase in tryptophan catabolites and a reduction in tyrosine catabolites. There was an increase in cholesterol phospholipid ratio and a reduction in glycoconjugate level of RBC membrane in patients with idiopathic pulmonary fibrosis. Isoprenoid pathway dysfunction con tributes to the pathogenesis of idiopathic pulmonary fibrosis. The biochemical patterns obtained in interstitial lung disease are similar to those obtained in left-handed/right hemispheric chemically dominant individuals by the dichotic listening test. However, all the patients with interstitial lung disease were right-handed/left hemispheric dominant by the dichotic listening test. Hemispheric chemical dominance has no correlation with handedness or the dichotic listening test. Interstitial lung disease occurs in right hemispheric chemically dominant individuals and is a reflection of altered brain function.

  19. Dominance as adaptive stressing and ranking of males, serving to allocate reproduction by differential self-suppressed fertility: towards a fully biological understanding of social systems.

    Science.gov (United States)

    Moxon, Steve

    2009-07-01

    Dominance is a biological concept of an asymmetric 'power' relationship between (any pair of) individuals, as a result of previous encounters with others biasing likelihood of contesting. That this requires dedicated neural structure shows that dominance is adaptive; and it is usually thought that fitness is increased through dominance (hierarchy) minimising mutually unproductive contest over resources, and/or determining access to or control over resources. But highly inconsistent data indicates that this operational definition is too wide, and given clear evidence that dominance is invariably same-sex, it would seem instead to function primarily to allocate reproduction. Dominance contest exposes individual differences in metabolic vigor especially, but also in various other, including sophisticated attributes; and by a self-organising process there is ranking of same-sex individuals in a hierarchy. But this achieves nothing in itself without an integral mechanism of corresponding individual variable self-suppression of the physiology re reproduction--and mate choice with rank as the criteria. Reproductive suppression would appear to vary along a continuum, from in some species (most 'cooperative breeders') a 100% reproductive skew with total suppression of all individuals bar the sole breeder to, in most others, a gradient down the length of the dominance hierarchy. The mechanism in most species is directly either hormonal or pheromonal, on top of an indirect consequence of the stress caused by relatively low rank. Dominance would seem to have evolved as a major instrument of the proposed 'genetic filter' function of the male, whereby in effect accumulated deleterious genetic material is 'quarantined' in the male half of the lineage from where it is purged, so as to keep this source of reproductive logjam away from females, thereby to avoid amplifying the problem of the female being necessarily the limiting factor in reproduction. The theory makes predictions

  20. Vernacular dominance in folk taxonomy: a case study of ethnospecies in medicinal plant trade in Tanzania.

    Science.gov (United States)

    Otieno, Joseph; Abihudi, Siri; Veldman, Sarina; Nahashon, Michael; van Andel, Tinde; de Boer, Hugo J

    2015-02-19

    Medicinal plants are traded as products with vernacular names, but these folk taxonomies do not always correspond one-to-one with scientific plant names. These local species entities can be defined as ethnospecies and can match, under-differentiate or over-differentiate as compared to scientific species. Identification of plant species in trade is further complicated by the processed state of the product, substitution and adulteration. In countries like Tanzania, an additional dimension to mapping folk taxonomies on scientific names is added by the multitude of ethnicities and languages of the plant collectors, traders and consumers. This study aims to elucidate the relations between the most common vernacular names and the ethnicity of the individual traders among the medicinal plant markets in Dar es Salaam and Tanga regions in Tanzania, with the aim of understanding the dynamics of vernacular names in plant trade. A total of 90 respondents were interviewed in local markets using semi-structured interviews. The ethnicity of each respondent was recorded, as well as the language of each ethnospecies mentioned during the interviews. Voucher collections and reference literature were used to match ethnospecies across languages. At each market, the language of the majority of the vendors dominates the names for medicinal products. The dominant vendors often represent the major ethnic groups of that region. Independent of their ethnicity, vendors offer their products in the dominant language of the specific region without apparently leading to any confusion or species mismatching. Middlemen, traders and vendors adapt their folk classifications to those of the ethnic groups of the region where they conduct their trade, and to the ethnicity of their main customers. The names in the language of the traders are not forgotten, but relegated in favor of the more salient names of the dominant tribe.

  1. Dominant Species in Subtropical Forests Could Decrease Photosynthetic N Allocation to Carboxylation and Bioenergetics and Enhance Leaf Construction Costs during Forest Succession.

    Science.gov (United States)

    Xiao, Yihua; Liu, Shirong; Tong, Fuchun; Chen, Bufeng; Kuang, Yuanwen

    2018-01-01

    It is important to understand how eco-physiological characteristics shift in forests when elucidating the mechanisms underlying species replacement and the process of succession and stabilization. In this study, the dominant species at three typical successional stages (early-, mid-, and late-succession) in the subtropical forests of China were selected. At each stage, we compared the leaf construction costs (CC), payback time (PBT), leaf area based N content ( N A ), maximum CO 2 assimilation rate ( P max ), specific leaf area (SLA), photosynthetic nitrogen use efficiency (PNUE), and leaf N allocated to carboxylation ( N C ), and to bioenergetics ( N B ). The relationships between these leaf functional traits were also determined. The results showed that the early-succession forest is characterized with significantly lower leaf CC, PBT, N A , but higher P max , SLA, PNUE, N C , and N B , in relation to the late-succession forest. From the early- to the late-succession forests, the relationship between P max and leaf CC strengthened, whereas the relationships between N B , N C , PNUE, and leaf CC weakened. Thus, the dominant species are able to decrease the allocation of the photosynthetic N fraction to carboxylation and bioenergetics during forest succession. The shift in these leaf functional traits and their linkages might represent a fundamental physiological mechanism that occurs during forest succession and stabilization.

  2. Hypothalamic digoxin, hemispheric chemical dominance, and mesenteric artery occlusion.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Paramesware Achutha

    2003-12-01

    The role of the isoprenoid pathway in vascular thrombosis, especially mesenteric artery occlusion and its relation to hemispheric dominance, was assessed in this study. The following parameters were measured in patients with mesenteric artery occlusion and individuals with right hemispheric, left hemispheric, and bihemispheric dominance: (1) plasma HMG CoA reductase, digoxin, dolichol, ubiquinone, and magnesium levels; (2) tryptophan/tyrosine catabolic patterns; (3) free radical metabolism; (4) glycoconjugate metabolism; and (5) membrane composition. In patients with mesenteric artery occlusion there was elevated digoxin synthesis, increased dolichol and glycoconjugate levels, low ubiquinone, and elevated free radical levels. The RBC membrane Na(+)-K+ ATPase activity and serum magnesium were decreased. There was also an increase in tryptophan catabolites and reduction in tyrosine catabolites in the serum. There was an increase in cholesterol:phospholipid ratio and a reduction in glycoconjugate level of RBC membrane in these patients. The biochemical patterns obtained in mesenteric artery occlusion is similar to those obtained in left-handed/right hemispheric dominant individuals by the dichotic listening test. But all the patients with mesenteric artery occlusion were right-handed/left hemispheric dominant by the dichotic listening test. Hemispheric chemical dominance has no correlation with handedness or the dichotic listening test. Mesenteric artery occlusion occurs in right hemispheric chemically dominant individuals and is a reflection of altered brain function. Hemispheric chemical dominance may thus control the risk for developing vascular thrombosis in individuals.

  3. Collective strategies and cyclic dominance in asymmetric predator-prey spatial games.

    Science.gov (United States)

    Cazaubiel, Annette; Lütz, Alessandra F; Arenzon, Jeferson J

    2017-10-07

    Predators may attack isolated or grouped prey in a cooperative, collective way. Whether a gregarious behavior is advantageous to each species depends on several conditions and game theory is a useful tool to deal with such a problem. We here extend the Lett et al. (2004) to spatially distributed populations and compare the resulting behavior with their mean-field predictions for the coevolving densities of predator and prey strategies. Besides its richer behavior in the presence of spatial organization, we also show that the coexistence phase in which collective and individual strategies for each group are present is stable because of an effective, cyclic dominance mechanism similar to a well-studied generalization of the Rock-Paper-Scissors game with four species, a further example of how ubiquitous this coexistence mechanism is. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Inactivation of Candida glabrata by a humid DC argon discharge afterglow: dominant contributions of short-lived aqueous active species

    Science.gov (United States)

    Xiong, Qing; Liu, Hongbin; Lu, Weiping; Chen, Qiang; Xu, Le; Wang, Xia; Zhu, Qunlin; Zeng, Xue; Yi, Ping

    2017-05-01

    Plasma medicine applications are currently attracting significant interest all over the world. Bactericidal treatments of Candida glabrata cultured in saline suspension are performed in this study by a room-temperature reactive afterglow of a DC-driven argon discharge. Water vapor was added to the discharge to study the inactivation contributions of reactive hydrolytic species including OH and H2O2 transporting along the gas flow to the treated solutions. The inactivation results indicate that the dominant roles in the bactericidal treatments are played by the short-lived aqueous active species, but not the stable species like H2O2aq (aq indicates an aqueous species). Further analysis shows that the ·OHaq radicals play an important role in the inactivation process. The ·OHaq radicals in the suspension are mostly produced from the direct dissolution of the OH species in the reactive afterglow. With the increase of added water vapor content, the ·OHaq production increases and enhances the inactivation efficiency of C. glabrata. Furthermore, it is found that the ambient air diffusion shows essential effects on the bactericidal activity of the remote humid argon discharge. Higher bactericidal effects can be obtained in open-space treatments compared to in a controlled Ar + H2O gas atmosphere. Key active air-byproduct species are believed to be generated in the suspension during the treatments and contributing to the inactivation process. Based on chemical analysis, the peroxynitrous acid ONOOHaq is considered as the key antimicrobial air-byproduct species. These results indicate the important dependence of plasma biomedical effects on the processing environment, which finally relates to the critical contributions of the key reactive species formed therein.

  5. 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.

  6. Hypothalamic digoxin, hemispheric dominance, and neurobiology of love and affection.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-05-01

    The human hypothalamus produces an endogenous membrane Na+-K+ ATPase inhibitor, digoxin, which can regulate neuronal transmission. The digoxin status and neurotransmitter patterns were studied in individuals with a predilection to fall in love. It was also studied in individuals with differing hemispheric dominance to find out the role of cerebral dominance in this respect. In individuals with a predilection to fall in love there was decreased digoxin synthesis, increased membrane Na+-K+ ATPase activity, decreased tryptophan catabolites (serotonin, quinolinic acid, and nicotine), and increased tyrosine catabolites (dopamine, noradrenaline, and morphine). This pattern correlated with that obtained in left hemispheric chemical dominance. Hemispheric dominance and hypothalamic digoxin could regulate the predisposition to fall in love.

  7. Species distribution & antifungal susceptibility pattern of oropharyngeal Candida isolates from human immunodeficiency virus infected individuals

    Directory of Open Access Journals (Sweden)

    Partha Pratim Das

    2016-01-01

    Results: From the 59 culture positive HIV seropositive cases, 61 Candida isolates were recovered; Candidaalbicans (n=47, 77.0%, C. dubliniensis (n=9, 14.7%, C. parapsilosis (n=2, 3.2%, C. glabrata (n=2, 3.2%, and C. famata (n=1, 1.6%. Candida colonization in HIV-seropositive individuals was significantly higher than that of HIV-seronegative (control group. Antifungal susceptibility testing revealed (n=6, 9.3% C. albicans isolates resistant to voriconazole and fluconazole by disk-diffusion method whereas no resistance was seen by Fungitest method. Interpretation & conclusions: C. albicans was the commonest Candida species infecting or colonizing HIV seropositive individuals. Oropharyngeal Candida isolates had high level susceptibility to all the major antifungals commonly in use. Increased level of immunosuppression in HIV-seropositives and drug resistance of non-albicans Candida species makes identification and susceptibility testing of Candida species necessary in different geographical areas of the country.

  8. Changes in the dominance hierarchy of captive female Japanese macaques as a consequence of merging two previously established groups.

    Science.gov (United States)

    Anderson, Emily J; Weladji, Robert B; Paré, Patrick

    2016-11-01

    Dominance hierarchies play an important role in reducing competition and aggression in social animals. In zoos, changes in group composition are often required due to management protocols, but these changes may have long lasting effects on dominance hierarchies, and, consequently, the wellbeing of the animals. We studied the changes in the female dominance hierarchy that occurred both during and after the formation of a group of 10 adult Japanese macaques at the Zoo de Granby by combining members from two previously established groups. There was no significant correlation between individual ranks in the old groups (groups A and B) and their ranks in the new group (group AB), indicating a significant change in the hierarchy. Alliances between kin appeared to be important in determining rank; when the sister of the dominant female was removed from group AB, the hierarchy changed significantly a second time. The average standardized rank of individuals added later in the formation process of group AB was not different from those added earlier. Ranks in the group AB did correlate with age of individual at the beginning of the field season, but not at the end, after the shift in hierarchy occurred. Zoo management must be aware of the consequences small changes in a social group can have when removing and transferring individuals in both primates and in other social species. Zoo Biol. 35:505-512, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  9. Extrinsic versus intrinsic hand muscle dominance in finger flexion.

    Science.gov (United States)

    Al-Sukaini, A; Singh, H P; Dias, J J

    2016-05-01

    This study aims to identify the patterns of dominance of extrinsic or intrinsic muscles in finger flexion during initiation of finger curl and mid-finger flexion. We recorded 82 hands of healthy individuals (18-74 years) while flexing their fingers and tracked the finger joint angles of the little finger using video motion tracking. A total of 57 hands (69.5%) were classified as extrinsic dominant, where the finger flexion was initiated and maintained at proximal interphalangeal and distal interphalangeal joints. A total of 25 (30.5%) were classified as intrinsic dominant, where the finger flexion was initiated and maintained at the metacarpophalangeal joint. The distribution of age, sex, dominance, handedness and body mass index was similar in the two groups. This knowledge may allow clinicians to develop more efficient rehabilitation regimes, since intrinsic dominant individuals would not initiate extrinsic muscle contraction till later in finger flexion, and might therefore be allowed limited early active motion. For extrinsic dominant individuals, by contrast, initial contraction of extrinsic muscles would place increased stress on the tendon repair site if early motion were permitted. © The Author(s) 2016.

  10. Potential phytotoxic and shading effects of invasive Fallopia (Polygonaceae taxa on the germination of native dominant species

    Directory of Open Access Journals (Sweden)

    Lenka Moravcová

    2011-08-01

    riparian-like habitats where it often encounters U. dioica populations, while F. ×bohemica tends to occur more often in ruderal sites with a high representation of C. epigejos; this might imply that each of the knotweed species exhibits a stronger effect on native species that are dominant in habitats they typically invade. The weakest phytotoxic effect of F. japonica corresponds to the results of previous studies that found this species to be generally a weaker competitor than its two congeners. Although the results of our experiments cannot be taken as a direct evidence for allelopathic effects acting in the field, the demonstrated potential phytotoxic effect of invasive Fallopia species on the germination of native species suggests that allelopathy may play a role in the strong impact of knotweed invasion on species diversity of invaded communities observed in the field.

  11. Bees (Hymenoptera, Apoidea, Apiformes in the Agricultural Landscape of Bulgaria: Species Diversity

    Directory of Open Access Journals (Sweden)

    Banaszak Józef

    2014-06-01

    Full Text Available Wild bees (Apiformes were studied in 4 crop fields and 8 refuge habitats for 2 - 5 years in agricultural landscapes in the Pleven and Plovdiv regions of Bulgaria. In total, 233 bee species were recorded. Bee forage plants visited by the honey bee and wild Apiformes are listed for each refuge habitat. Species composition is given for individual habitats, including fields of alfalfa (Medicago sativa, oilseed rape (Brassica napus, sunflower (Helianthus annuus, and radish (Raphanus sativus. Species richness and dominance structure of bee communities in the 2 regions are compared, and species responsible for significant differences are identified.

  12. Inactivation of Candida glabrata by a humid DC argon discharge afterglow: dominant contributions of short-lived aqueous active species

    International Nuclear Information System (INIS)

    Xiong, Qing; Liu, Hongbin; Xu, Le; Wang, Xia; Zhu, Qunlin; Lu, Weiping; Chen, Qiang; Zeng, Xue; Yi, Ping

    2017-01-01

    Plasma medicine applications are currently attracting significant interest all over the world. Bactericidal treatments of Candida glabrata cultured in saline suspension are performed in this study by a room-temperature reactive afterglow of a DC-driven argon discharge. Water vapor was added to the discharge to study the inactivation contributions of reactive hydrolytic species including OH and H 2 O 2 transporting along the gas flow to the treated solutions. The inactivation results indicate that the dominant roles in the bactericidal treatments are played by the short-lived aqueous active species, but not the stable species like H 2 O 2aq (aq indicates an aqueous species). Further analysis shows that the ·OH aq radicals play an important role in the inactivation process. The ·OH aq radicals in the suspension are mostly produced from the direct dissolution of the OH species in the reactive afterglow. With the increase of added water vapor content, the ·OH aq production increases and enhances the inactivation efficiency of C. glabrata . Furthermore, it is found that the ambient air diffusion shows essential effects on the bactericidal activity of the remote humid argon discharge. Higher bactericidal effects can be obtained in open-space treatments compared to in a controlled Ar + H 2 O gas atmosphere. Key active air-byproduct species are believed to be generated in the suspension during the treatments and contributing to the inactivation process. Based on chemical analysis, the peroxynitrous acid ONOOH aq is considered as the key antimicrobial air-byproduct species. These results indicate the important dependence of plasma biomedical effects on the processing environment, which finally relates to the critical contributions of the key reactive species formed therein. (paper)

  13. Trace Elements in Dominant Species of the Fenghe River, China: Their Relations to Environmental Factors.

    Science.gov (United States)

    Yang, Yang; Zhou, Zhengchao; Bai, Yanying; Jiao, Wentao; Chen, Weiping

    2016-07-01

    The distribution of trace elements (TEs) in water, sediment, riparian soil and dominant plants was investigated in the Fenghe River, Northwestern China. The Fenghe River ecosystem was polluted with Cd, Cr, Hg and Pb. There was a high pollution risk in the midstream and downstream regions and the risk level for Cd was much higher than that of the other elements. The average values of bioconcentration coefficient for Cd and Zn were 2.21 and 1.75, respectively, indicating a large accumulation of Cd and Zn in the studied species. With broad ecological amplitudes, L. Levl. et Vant. Trin., and L. had the greatest TE concentrations in aboveground and belowground biomass of the studied species and were potential biomonitors or phytoremediators for the study area. Multivariate techniques including cluster analysis, correlation analysis, principal component analysis, and canonical correspondence analysis were used to analyze the relations between TE concentrations in plants and various environmental factors. The soil element concentration is the main factor determining the accumulation of TEs in plants. The co-release behavior of common pollutants and TEs drove the accumulation of Hg, Cd, and As in the studied plants. Significant enrichment of some elements in the Fenghe River has led to a decline in the biodiversity of plants. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  14. Antioxidant Activity of Dominant Plants Species in Obat Pahit from Lingga Malay Ethnic in Riau Archipelago

    Directory of Open Access Journals (Sweden)

    Fitmawati Fitmawati

    2017-07-01

    Full Text Available Obat Pahit is a potion that has been long commonly consumed by Lingga Malay society for generations as stamina keeper. The most dominant plants found in the packaging of the Obat Pahit were namely Bauhunia semibifida, Cnestis palala and Penawa Root (3 species. This research aimed to investigate and determine activity of antioxidant contents in Obat Pahit from five Traditional Medicine Practitioners (TMPs in the district of Lingga. The tested samples were mashed then being soaked into 2 types of solvent: distilled water and methanol, containing HCl 1%. DPPH method was also used in this research. Quantitatively antioxidant activity test of Obat Pahit from the five TMPs by using methanol solvent had extremely highest activity compared to the distilled water solvent. The test, using TLC plate by spraying the extract from three dominant plants with 0.1 mM of DPPH solution, produced a pale-yellow spots at a wavelength of 366 nm. On the other hand, the test using HPLC at wavelengths of 230 nm and 280 nm showed the presence of two dominant secondary metabolites contents: flavonoid and phenolic. IC50 (ppm of Bauhinia semibifida (6.6247, Penawa Root (5.0124 and Cnestis palala (5.9968 were much lower than IC50 of mangosteen’s rind (41.7675, vitamin C (6.6612 and Stimuno drug (8.333. This antioxidant analysis has not been reported previously. This proof contributed greatly to uncovering potentially native natural resources as an indigenous Indonesian drug which is expected to decrease dependence on imported drugs especially imunomodulator, antihypertensive, antidiabet etc. This research would be beneficial and excellent manifestation for the development of natural antioxidant-based medicines from traditional knowledge of Indonesia’s local ethnicities.

  15. Sex-reversed correlation between stress levels and dominance rank in a captive non-breeder flock of crows.

    Science.gov (United States)

    Ode, Minami; Asaba, Akari; Miyazawa, Eri; Mogi, Kazutaka; Kikusui, Takefumi; Izawa, Ei-Ichi

    2015-07-01

    Group living has both benefits and costs to individuals; benefits include efficient acquisition of resources, and costs include stress from social conflicts among group members. Such social challenges result in hierarchical dominance ranking among group members as a solution to avoid escalating conflict that causes different levels of basal stress between individuals at different ranks. Stress-associated glucocorticoid (corticosterone in rodents and birds; CORT) levels are known to correlate with dominance rank in diverse taxa and to covary with various social factors, such as sex and dominance maintenance styles. Although there is much evidence for sex differences in the basal levels of CORT in various species, the correlation of sex differences in basal CORT with dominance rank is poorly understood. We investigated the correlation between CORT metabolites (CM) in the droppings and social factors, including rank and sex, in a captive non-breeder group of crows. In this group, all the single males dominated all the single females, and dominance ranks were stable among single males but relatively unstable among single females. CM levels and rank were significantly correlated in a sex-reversed fashion: males at higher rank (i.e., more dominant) had higher CM, whereas females at higher rank exhibited lower CM. This is the first evidence of sex-reversed patterns of CM-rank correlation in birds. The results suggest that different mechanisms of stress-dominance relationships operate on the sexes in non-breeder crow aggregations; in males, stress is associated with the cost of aggressive displays, whereas females experience subordination stress due to males' overt aggression. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Can native plant species be preserved in an anthropogenic forest landscape dominated by aliens? A case study from Mediterranean Chile

    Directory of Open Access Journals (Sweden)

    Steffi Heinrichs

    2016-06-01

    Full Text Available Plantations with fast growing exotic tree species can negatively affect native plant species diversity and promote the spread of alien species. Mediterranean Chile experienced major landscape changes with a vast expansion of industrial plantations of Pinus radiata in the past. However, with increasing knowledge of biodiversity effects on ecosystem services Chilean forest owners now aim to integrate the conservation of native biodiversity into forest management, but data on native species diversity and establishment within a plantation landscape is scarce. Here we investigated plant species diversity and composition in four forest management options applied within a landscape dominated by P. radiata plantations in comparison to an unmanaged reference: (i a clear cut, (ii a strip cut, (iii a native canopy of Nothofagus glauca and (iv a young P. radiata plantation. We wanted to assess if native plant species can be maintained either by natural regeneration or by planting of native tree species (Nothofagus glauca, N. obliqua, Quillaja saponaria within this landscape. Results show a high diversity of native and forest plant species within the different management options indicating a high potential for native biodiversity restoration within an anthropogenic landscape. In particular, herbaceous species can benefit from management. They are rare in unmanaged natural forests that are characterized by low light conditions and a thick litter layer. Management, however, also promoted a diversity of alien species. The rapid spread of alien grass species after management can deter an initial establishment of native tree species or the survival and growth after planting mainly under dry but less under sufficient moisture conditions. The most unsuccessful option for promoting native plant species was clear cutting in a dry area where alien grasses were abundant. For drought-tolerant tree species such as Quillaja saponaria, though

  17. Ecomorphology of Astyanax species in streams with different substrates

    Directory of Open Access Journals (Sweden)

    Marcela A. Souza

    2014-02-01

    Full Text Available In the present study, we assessed the ecomorphology of two species of Astyanax in streams with different substrates found in the Rio São Francisco Basin. The dominant substrate of each stream was defined as either "fine" (0 to 2 mm, "gravel" (2 to 250 mm, "rock" (> 250 mm, or "leaf bank". We analyzed a total of 22 ecomorphological attributes of Astyanax intermedius Eigenmann, 1908 (127 individuals and Astyanax rivularis (Lütken, 1875 (238 individuals adults. We detected significant ecomorphological differences between the populations of A. rivularis and A. intermedius from habitats with different types of substrates. However, the two species did not show the same morphological differences depending on the type of substrate. These results confirmed the hypothesis that individuals from environments with different characteristics may have different ecomorphological patterns. Knowing that morphology is associated with habitat use and available resources, the loss of a resource or a modification in the environment may directly affect the permanence of a species, leading to a loss of morphologic diversity.

  18. Social dominance in context and in individuals: contextual moderation of robust effects of social dominance orientation in 15 languages and 20 countries

    NARCIS (Netherlands)

    Pratto, F.; Cidam, A.; Stewart, E.L.; Bou Zeinedinne, F.; Aranda, M.; Aiello, M.; Chryssochoou, X.; Cichocka, A.; Cohrs, C.; Durrheim, K.; Eicher, V.; Foels, R.; Górska, P.; Lee, I-C; Licata, L.; Liu, L.; Liu, J.H.; Meyer, I.; Morselli, D.; Muldoon, O.; Muluk, H.; Petrovic, I.; Petrovic, N.; Prati, F.; Papastamou, S.; Prodromitis, G.; Rubini, M.; Saab, R.; van Stekelenburg, J.; Sweetman, J.; Zheng, W.; Henkel, K.

    2013-01-01

    We tested the internal reliability and predictive validity of a new 4-item Short Social Dominance Orientation (SSDO) scale among adults in 20 countries, using 15 languages (N = 2,130). Low scores indicate preferring group inclusion and equality to dominance. As expected, cross-nationally, the lower

  19. Individual Phosphatidylcholine Species Analysis by RP-HPLC-ELSD for Determination of Polyenylphosphatidylcholine in Lecithins.

    Science.gov (United States)

    Lee, Wei-Ju; Weng, Shun-Hsiang; Su, Nan-Wei

    2015-04-22

    Polyenylphosphatidylcholine (PPC), a subgroup of the bioactive agents in phosphatidylcholine (PC), has been indicated to possess liver-protective effects. This study aimed to investigate a promising and feasible method to determine PC molecular species with a reverse phase (RP) high-performance liquid chromatograph (HPLC) equipped with an evaporative light scattering detector (ELSD). Chromatography was achieved using a C30 column and an isocratic mobile phase consisting of acetonitrile/methanol/triethylamine (40/58/2, v/v/v) at a flow rate of 1 mL/min, and ELSD detection was performed using 80 °C for the drift tube and an air flow rate of 1.8 L/min. To identify individual peaks on the chromatogram, MALDI-TOF-MS was employed for initial detection, and then the results were used to investigate the relationship between the retention time and fatty acyl chains of each PC molecule. A linear correlation was observed between the retention time and theoretical carbon number (TCN) of individual PC species. The compositions of PC molecular species in soybean and sunflower lecithins were similar to each other, and the major PC molecular species were 1,2-dilinoleoyl-sn-glycero-3-phosphocholine (LLPC), 1-oleoyl-2-linoleoyl-sn-glycero-3-phosphocholine (OLPC), and 1-palmitoyl-2-linoleoyl-sn-glycero-3-phosphocholine (PLPC). The contents of LLPC in soybean PC and sunflower PC were 40.6% and 64.3%, respectively.

  20. Checklist comparison and dominance patterns of the fish fauna at Taim Wetland, South Brazil

    Directory of Open Access Journals (Sweden)

    Alexandre M. Garcia

    Full Text Available Taim Hydrological System is a unique subtropical wetland in southern Brazil harboring an exceptional biological diversity. In 1978, an ecological reserve was established to protect part of this area from increasing anthropogenic impacts in its surroundings. Fishes have been poorly investigated in this system. Based on a multi-gear sampling study encompassing several years (2001-2005, and on comparisons with previous fish inventories, we provide an up-to-date species list of fishes occurring in the Taim Wetland. In addition, we made the first preliminary description of fish dominance patterns found in the main lakes of the system (Flores, Nicola, Jacaré and Mangueira. Checklist comparison resulted in 62 fish species distributed in 24 families, with Characidae (19 species and Cichlidae (7 showing the highest species richness. Six species are cited for the first time in the reserve: Trachelyopterus lucenai (Auchenipteridae, Hoplosternum littorale (Callichthyidae, Rineloricaria cadeae (Loricariidae, Eigenmannia trilineata (Sternopygidae, Odontesthes mirinensis and O. perugiae (Atherinopsidae. Apparently, the black catfish T. lucenai invaded the system in the last decade and became one of the dominant species in the pelagic waters. Although differences in gears hindered direct comparisons, differences in species composition and dominance patterns between shallow margins and pelagic waters of lakes seem to occur in the lakes. A more diverse assemblage dominated by small fishes ( 15 cm seemed to dominate in pelagic waters.

  1. mangrove litter production and seasonality of dominant species

    African Journals Online (AJOL)

    L.A

    storminess, and sea-level rise (Snedaker, 1995; Nigel, 1998). In the last .... mangrove species (three-levels) were entered as fixed factors, with the total litter components ..... Mangroves and climate change in the Florida and Caribbean region:.

  2. Dominant forest tree species are potentially vulnerable to climate change over large portions of their range even at high latitudes

    Directory of Open Access Journals (Sweden)

    Catherine Périé

    2016-07-01

    Full Text Available Projecting suitable conditions for a species as a function of future climate provides a reasonable, although admittedly imperfect, spatially explicit estimate of species vulnerability associated with climate change. Projections emphasizing range shifts at continental scale, however, can mask contrasting patterns at local or regional scale where management and policy decisions are made. Moreover, models usually show potential for areas to become climatically unsuitable, remain suitable, or become suitable for a particular species with climate change, but each of these outcomes raises markedly different ecological and management issues. Managing forest decline at sites where climatic stress is projected to increase is likely to be the most immediate challenge resulting from climate change. Here we assess habitat suitability with climate change for five dominant tree species of eastern North American forests, focusing on areas of greatest vulnerability (loss of suitability in the baseline range in Quebec (Canada rather than opportunities (increase in suitability. Results show that these species are at risk of maladaptation over a remarkably large proportion of their baseline range. Depending on species, 5–21% of currently climatically suitable habitats are projected to be at risk of becoming unsuitable. This suggests that species that have traditionally defined whole regional vegetation assemblages could become less adapted to these regions, with significant impact on ecosystems and forest economy. In spite of their well-recognised limitations and the uncertainty that remains, regionally-explicit risk assessment approaches remain one of the best options to convey that message and the need for climate policies and forest management adaptation strategies.

  3. Dominant forest tree species are potentially vulnerable to climate change over large portions of their range even at high latitudes.

    Science.gov (United States)

    Périé, Catherine; de Blois, Sylvie

    2016-01-01

    Projecting suitable conditions for a species as a function of future climate provides a reasonable, although admittedly imperfect, spatially explicit estimate of species vulnerability associated with climate change. Projections emphasizing range shifts at continental scale, however, can mask contrasting patterns at local or regional scale where management and policy decisions are made. Moreover, models usually show potential for areas to become climatically unsuitable, remain suitable, or become suitable for a particular species with climate change, but each of these outcomes raises markedly different ecological and management issues. Managing forest decline at sites where climatic stress is projected to increase is likely to be the most immediate challenge resulting from climate change. Here we assess habitat suitability with climate change for five dominant tree species of eastern North American forests, focusing on areas of greatest vulnerability (loss of suitability in the baseline range) in Quebec (Canada) rather than opportunities (increase in suitability). Results show that these species are at risk of maladaptation over a remarkably large proportion of their baseline range. Depending on species, 5-21% of currently climatically suitable habitats are projected to be at risk of becoming unsuitable. This suggests that species that have traditionally defined whole regional vegetation assemblages could become less adapted to these regions, with significant impact on ecosystems and forest economy. In spite of their well-recognised limitations and the uncertainty that remains, regionally-explicit risk assessment approaches remain one of the best options to convey that message and the need for climate policies and forest management adaptation strategies.

  4. Canopy Transpiration and Stomatal Responses to Prolonged Drought by a Dominant Desert Species in Central Asia

    Directory of Open Access Journals (Sweden)

    Daxing Gu

    2017-06-01

    Full Text Available In arid and semiarid lands, canopy transpiration and its dynamics depend largely on stomatal sensitivity to drought. In this study, the sap flow of a dominant species, Haloxylon ammodendron growing in Central Asian deserts, was monitored using Granier-type sensors, from which the canopy stomatal conductance was derived. The responses of canopy transpiration and stomatal conductance to environmental variables during the second half of the growing season, when annual prolonged drought occurred, was analyzed for four continuous years, from 2013 to 2016. A soil water content (SWC of 3% was identified as the lower soil water threshold for this species, below which the plant lost the ability for stomatal regulation on water loss and suffered the risk of mortality. Above this threshold, the sensitivity of canopy transpiration to vapor pressure deficit, VPD (K, was linearly correlated with SWC, which mainly resulted from different stomatal behaviors at varying drought intensities. Stomatal sensitivity to VPD (m/Gsref increased linearly with soil moisture deficit, inducing a shift from more anisohydric to a more isohydric stomatal behavior. The flexibility of stomatal behavior regarding soil drought was one key element facilitating the survival of H. ammodendron in such an extreme dry environment.

  5. Phenotypic and genotypic characterization of lactic acid bacteria isolated from raw goat milk and effect of farming practices on the dominant species of lactic acid bacteria.

    Science.gov (United States)

    Tormo, Hélène; Ali Haimoud Lekhal, Djamila; Roques, C

    2015-10-01

    Lactic acid bacteria, in particular Lactococcus lactis, play a decisive role in the cheese making process and more particularly in lactic cheeses which are primarily produced on goat dairy farms. The objective of this study was therefore to identify the main lactic acid bacteria found in raw goats' milk from three different regions in France and evaluate if certain farming practices have an effect on the distribution of species of lactic acid bacteria in the various milk samples. Identification at genus or species level was carried out using phenotypic tests and genotypic methods including repetitive element REP-PCR, species-specific PCR and 16S rRNA gene sequencing. The distribution of the main bacterial species in the milk samples varied depending on farms and their characteristics. Out of the 146 strains identified, L. lactis was the dominant species (60% of strains), followed by Enterococcus (38%) of which Enterococcus faecalis and Enterococcus faecium. Within the species L. lactis, L. lactis subsp lactis was detected more frequently than L. lactis subsp cremoris (74% vs. 26%). The predominance of L. lactis subsp cremoris was linked to geographical area studied. It appears that the animals' environment plays a role in the balance between the dominance of L. lactis and enterococci in raw goats' milk. The separation between the milking parlor and the goat shed (vs no separation) and only straw in the bedding (vs straw and hay) seems to promote L. lactis in the milk (vs enterococci). Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Gene expression variation resolves species and individual strains among coral-associated dinoflagellates within the genus Symbiodinium

    KAUST Repository

    Parkinson, John Everett; Baumgarten, Sebastian; Michell, Craig; Baums, Iliana B.; LaJeunesse, Todd C.; Voolstra, Christian R.

    2016-01-01

    Reef-building corals depend on symbiotic mutualisms with photosynthetic dinoflagellates in the genus Symbiodinium. This large microalgal group comprises many highly divergent lineages (“Clades A-I”) and hundreds of undescribed species. Given their ecological importance, efforts have turned to genomic approaches to characterize the functional ecology of Symbiodinium. To date, investigators have only compared gene expression between representatives from separate clades—the equivalent of contrasting genera or families in other dinoflagellate groups—making it impossible to distinguish between clade-level and species-level functional differences. Here, we examined the transcriptomes of four species within one Symbiodinium clade (Clade B) at ~20,000 orthologous genes, as well as multiple isoclonal cell lines within species (i.e. cultured strains). These species span two major adaptive radiations within Clade B, each encompassing both host-specialized and ecologically cryptic taxa. Species-specific expression differences were consistently enriched for photosynthesis-related genes, likely reflecting selection pressures driving niche diversification. Transcriptional variation among strains involved fatty acid metabolism and biosynthesis pathways. Such differences among individuals are potentially a major source of physiological variation, contributing to the functional diversity of coral holobionts composed of unique host-symbiont genotype pairings. Our findings expand the genomic resources available for this important symbiont group and emphasize the power of comparative transcriptomics as a method for studying speciation processes and inter-individual variation in non-model organisms.

  7. Gene expression variation resolves species and individual strains among coral-associated dinoflagellates within the genus Symbiodinium

    KAUST Repository

    Parkinson, John Everett

    2016-02-11

    Reef-building corals depend on symbiotic mutualisms with photosynthetic dinoflagellates in the genus Symbiodinium. This large microalgal group comprises many highly divergent lineages (“Clades A-I”) and hundreds of undescribed species. Given their ecological importance, efforts have turned to genomic approaches to characterize the functional ecology of Symbiodinium. To date, investigators have only compared gene expression between representatives from separate clades—the equivalent of contrasting genera or families in other dinoflagellate groups—making it impossible to distinguish between clade-level and species-level functional differences. Here, we examined the transcriptomes of four species within one Symbiodinium clade (Clade B) at ~20,000 orthologous genes, as well as multiple isoclonal cell lines within species (i.e. cultured strains). These species span two major adaptive radiations within Clade B, each encompassing both host-specialized and ecologically cryptic taxa. Species-specific expression differences were consistently enriched for photosynthesis-related genes, likely reflecting selection pressures driving niche diversification. Transcriptional variation among strains involved fatty acid metabolism and biosynthesis pathways. Such differences among individuals are potentially a major source of physiological variation, contributing to the functional diversity of coral holobionts composed of unique host-symbiont genotype pairings. Our findings expand the genomic resources available for this important symbiont group and emphasize the power of comparative transcriptomics as a method for studying speciation processes and inter-individual variation in non-model organisms.

  8. Vertebrate Herbivore Browsing on Neighboring Forage Species Increases the Growth and Dominance of Siberian Alder Across a Latitudinal Transect in Northern Alaska.

    Science.gov (United States)

    McNeill, E. M.; Ruess, R. W.

    2017-12-01

    Vertebrate herbivores strongly influence plant growth and architecture, biogeochemical cycling, and successional dynamics in boreal and arctic ecosystems. One of the most notable impacts of vertebrate herbivory is on the growth and spread of alder, a chemically-defended, N-fixing shrub whose distribution in the Alaskan arctic has expanded dramatically over the past 60 years. Although herbivore effects on thin-leaf alder are well described for interior Alaskan floodplains, no work has been conducted on the effects of herbivores on Siberian alder (Alnus viridis spp fruticosa), despite the increasing importance of this species to high latitude ecosystems. We characterized browsing by snowshoe hares, moose, and willow ptarmigan on dominant shrub species across topo-edaphic sequences within 5 ecoregions along a 600 km latitudinal transect extending from interior Alaska to the North Slope. Ptarmigan browsed wind-blown lowland and alpine sites devoid of trees in all regions; moose browsed predominantly willow species in hardwood and mixed forests and were absent north of the Brooks Range; snowshoe hares selected habitats and forage based on their local density and vulnerability to predators. Browsing intensity on Siberian alder was either undetectable or low, limited primarily to hare browsing on young ramets in the northern boreal forest where hare density relative to forage availability is highest. Overall, alder height growth was positively correlated with levels of herbivory on competing shrub species. Our data support the hypothesis that vertebrate herbivore browsing is indirectly augmenting the growth, dominance, and possible spread of Siberian alder throughout its northern Alaskan range. Given the potential high rates of N-fixation inputs by Siberian alder, we believe herbivores are also having strong indirect effects on biogeochemical cycling and possibly C storage in these landscapes.

  9. Inter-individual relationships in proboscis monkeys: a preliminary comparison with other non-human primates.

    Science.gov (United States)

    Matsuda, Ikki; Tuuga, Augustine; Bernard, Henry; Furuichi, Takeshi

    2012-01-01

    This is the first report on inter-individual relationships within a one-male group of proboscis monkeys (Nasalis larvatus) based on detailed identification of individuals. From May 2005 to 2006, focal and ad libitum data of agonistic and grooming behaviour were collected in a forest along the Menanggul River, Sabah, Malaysia. During the study period, we collected over 1,968 h of focal data on the adult male and 1,539 h of focal data on the six females. Their social interactions, including agonistic and grooming behaviour, appeared to follow typical patterns reported for other colobines: the incidence of social interaction within groups is low. Of 39 agonistic events, 26 were displacement from sleeping places along the river, 6 were the α male threatening other monkeys to mediate quarrels between females and between females and juveniles, and 7 were displacement from feeding places. Although the agonistic behaviour matrix based on the 33 intra-group agonistic events (excluding events between adults and juveniles and between adults and infants) was indicative of non-significant linearity, there were some specific dominated individuals within the group of proboscis monkeys. Nonetheless, grooming behaviour among adult females within a group were not affected by the dominance hierarchy. This study also conducted initial comparisons of grooming patterns among proboscis monkeys and other primate species. On the basis of comparison of their grooming networks, similar grooming patterns among both-sex-disperse and male-philopatric/female-disperse species were detected. Because adult females in these species migrate to groups repeatedly, it may be difficult to establish the firm grooming exchange relationship for particular individuals within groups, unlike in female-philopatric/male-disperse species. However, grooming distribution patterns within groups among primate species were difficult to explain solely on the basis of their dispersal patterns. Newly immigrated females

  10. Metagenomic analysis of the microbial community in fermented grape marc reveals that Lactobacillus fabifermentans is one of the dominant species: insights into its genome structure

    DEFF Research Database (Denmark)

    Campanaro, Stefano; Treu, Laura; Vendramin, Veronica

    2014-01-01

    species after 30 days of incubation and made it possible to identify those species that are able to grow in that extreme environment. The genome sequence of Lactobacillus fabifermentans, one of the dominant species identified, was then analyzed using shotgun sequencing and comparative genomics....... The results revealed that it is one of the largest genomes among the Lactobacillus sequenced and is characterized by a large number of genes involved in carbohydrate utilization and in the regulation of gene expression. The genome was shaped through a large number of gene duplication events, while lateral...... gene transfer contributed to a lesser extent with respect to other Lactobacillus species. According to genomic analysis, its carbohydrate utilization pattern and ability to form biofilm are the main genetic traits linked to the adaptation the species underwent permitting it to grow in fermenting grape...

  11. Hypothalamic digoxin, hemispheric chemical dominance, and peptic ulcer disease.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-10-01

    The isoprenoid pathway produces three key metabolites--endogenous digoxin-like factor (EDLF) (membrane sodium-potassium ATPase inhibitor and regulator of neurotransmitter transport), ubiquinone (free radical scavenger), and dolichol (regulator of glycoconjugate metabolism). The pathway was assessed in peptic ulcer and acid peptic disease and its relation to hemispheric dominance studied. The activity of HMG CoA reductase, serum levels of EDLF, magnesium, tryptophan catabolites, and tyrosine catabolites were measured in acid peptic disease, right hemispheric dominant, left hemispheric dominant, and bihemispheric dominant individuals. All the patients with peptic ulcer disease were right-handed/left hemispheric dominant by the dichotic listening test. The pathway was upregulated with increased EDLF synthesis in peptic ulcer disease (PUD). There was increase in tryptophan catabolites and reduction in tyrosine catabolites in these patients. The ubiquinone levels were low and free radical production increased. Dolichol and glycoconjugate levels were increased and lysosomal stability reduced in patients with acid peptic disease (APD). There was increase in cholesterol:phospholipid ratio with decreased glyco conjugate levels in membranes of patients with PUD. Acid peptic disease represents an elevated EDLF state which can modulate gastric acid secretion and the structure of the gastric mucous barrier. It can also lead to persistence of Helicobacter pylori infection. The biochemical pattern obtained in peptic ulcer disease is similar to those obtained in left-handed/right hemispheric chemically dominant individuals. But all the patients with peptic ulcer disease were right-handed/left hemispheric dominant by the dichotic listen ing test. Hemispheric chemical dominance has no correlation with handedness or the dichotic listening test. Peptic ulcer disease occurs in right hemispheric chemically dominant individuals and is a reflection of altered brain function.

  12. Morphometric and molecular identification of individual barnacle cyprids from wild plankton: an approach to detecting fouling and invasive barnacle species.

    Science.gov (United States)

    Chen, Hsi-Nien; Høeg, Jens T; Chan, Benny K K

    2013-01-01

    The present study used DNA barcodes to identify individual cyprids to species. This enables accurate quantification of larvae of potential fouling species in the plankton. In addition, it explains the settlement patterns of barnacles and serves as an early warning system of unwanted immigrant species. Sequences from a total of 540 individual cypris larvae from Taiwanese waters formed 36 monophyletic clades (species) in a phylogenetic tree. Of these clades, 26 were identified to species, but 10 unknown monophyletic clades represented non-native species. Cyprids of the invasive barnacle, Megabalanus cocopoma, were identified. Multivariate analysis of antennular morphometric characters revealed three significant clusters in a nMDS plot, viz. a bell-shaped attachment organ (most species), a shoe-shaped attachment organ (some species), and a spear-shaped attachment organ (coral barnacles only). These differences in attachment organ structure indicate that antennular structures interact directly with the diverse substrata involved in cirripede settlement.

  13. Lactobacillus species as biomarkers and agents that can promote various aspects of vaginal health

    Directory of Open Access Journals (Sweden)

    Mariya Ivanova Petrova

    2015-03-01

    Full Text Available The human body is colonized by a vast number of microorganisms collectively referred to as the human microbiota. One of the main microbiota body sites is the female genital tract, commonly dominated by Lactobacillus spp., in approximately 70% of women. Each individual species can constitute approximately 99% of the ribotypes observed in any individual woman. The most frequently isolated species are Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus jensenii and Lactobacillus iners. Residing at the port of entry of bacterial and viral pathogens, the vaginal Lactobacillus species can create a barrier against pathogen invasion since mainly products of their metabolism secreted in the cervicovaginal fluid can play an important role in the inhibition of bacterial and viral infections. Therefore, a Lactobacillus-dominated microbiota appears to be a good biomarker for a healthy vaginal ecosystem. This balance can be rapidly altered during processes such as menstruation, sexual activity, pregnancy and various infections. An abnormal vaginal microbiota is characterized by an increased diversity of microbial species, leading to a condition known as bacterial vaginosis. Information on the vaginal microbiota can be gathered from the analysis of cervicovaginal fluid, by using the Nugent scoring or the Amsel’s criteria, or at the molecular level by investigating the number and type of Lactobacillus species. However, when translating this to the clinical setting, it should be noted that the absence of a Lactobacillus-dominated microbiota does not appear to directly imply a diseased condition or dysbiosis. Nevertheless, the widely documented beneficial role of vaginal Lactobacillus species demonstrates the potential of data on the composition and activity of lactobacilli as biomarkers for vaginal health. The substantiation and further validation of such biomarkers will allow the design of better targeted probiotic strategies.

  14. Effect of litter, leaf cover and cover of basal internodes of the dominant species Molinia caerulea on seedling recruitment and established vegetation

    Science.gov (United States)

    Janeček, Štěpán; Lepš, Jan

    2005-09-01

    The effects of litter removal, leaf cover of established plants and cover of basal internodes of a dominant species Molinia caerulea on seedling germination and the dynamics of established plants were studied in a field experiment in an oligotrophic wet meadow. Although the negative influence of litter on total seedling number and seedling species composition was non-significant, litter significantly affected the dynamics of the established vegetation and caused inhibition of total leaf cover development. The effects of total leaf cover of established plants on seedling establishment changed during the vegetation season. Whereas the effect of total leaf cover was positive at the start and in the middle of the vegetation season, at the end the total leaf cover negatively affected seedling establishment. Both total leaf cover and cover of basal internodes affected seedling composition. Effects of these two variables were statistically separable suggesting that they are based on different mechanisms. The response of seedling establishment to these factors was species specific and, consequently, our data support the hypothesis that that biotically generated spatial heterogeneity can promote species co-existence through the differentiation of species regeneration niches.

  15. Oxygen isotope fractionations across individual leaf carbohydrates in grass and tree species.

    Science.gov (United States)

    Lehmann, Marco M; Gamarra, Bruno; Kahmen, Ansgar; Siegwolf, Rolf T W; Saurer, Matthias

    2017-08-01

    Almost no δ 18 O data are available for leaf carbohydrates, leaving a gap in the understanding of the δ 18 O relationship between leaf water and cellulose. We measured δ 18 O values of bulk leaf water (δ 18 O LW ) and individual leaf carbohydrates (e.g. fructose, glucose and sucrose) in grass and tree species and δ 18 O of leaf cellulose in grasses. The grasses were grown under two relative humidity (rH) conditions. Sucrose was generally 18 O-enriched compared with hexoses across all species with an apparent biosynthetic fractionation factor (ε bio ) of more than 27‰ relative to δ 18 O LW , which might be explained by isotopic leaf water and sucrose synthesis gradients. δ 18 O LW and δ 18 O values of carbohydrates and cellulose in grasses were strongly related, indicating that the leaf water signal in carbohydrates was transferred to cellulose (ε bio  = 25.1‰). Interestingly, damping factor p ex p x , which reflects oxygen isotope exchange with less enriched water during cellulose synthesis, responded to rH conditions if modelled from δ 18 O LW but not if modelled directly from δ 18 O of individual carbohydrates. We conclude that δ 18 O LW is not always a good substitute for δ 18 O of synthesis water due to isotopic leaf water gradients. Thus, compound-specific δ 18 O analyses of individual carbohydrates are helpful to better constrain (post-)photosynthetic isotope fractionation processes in plants. © 2017 John Wiley & Sons Ltd.

  16. Non-native tree species in urban areas of the city of Nitra

    International Nuclear Information System (INIS)

    Galis, M

    2014-01-01

    Non-native plant species are part of our environment. The introduction of these species is huge conditioned by anthropogenic activities, such as the urban environment is characterized by. During the field surveys of selected town Nitra (Chrenova, Mikova Ves, Zobor), we studied the frequency of non-native tree species in the contact zone. Overall, we found out the presence of 10 alien species, observed in this area. Our results show dominant presence of the species Rhus typhina, followed by the Robinia pseudoacacia and Ailanthus altissima. Individual plants were tied largely to the surrounding of built-up areas, often growns directly in front of houses, or as a part of urban green. (author)

  17. Neural mechanisms of social dominance

    Science.gov (United States)

    Watanabe, Noriya; Yamamoto, Miyuki

    2015-01-01

    In a group setting, individuals' perceptions of their own level of dominance or of the dominance level of others, and the ability to adequately control their behavior based on these perceptions are crucial for living within a social environment. Recent advances in neural imaging and molecular technology have enabled researchers to investigate the neural substrates that support the perception of social dominance and the formation of a social hierarchy in humans. At the systems' level, recent studies showed that dominance perception is represented in broad brain regions which include the amygdala, hippocampus, striatum, and various cortical networks such as the prefrontal, and parietal cortices. Additionally, neurotransmitter systems such as the dopaminergic and serotonergic systems, modulate and are modulated by the formation of the social hierarchy in a group. While these monoamine systems have a wide distribution and multiple functions, it was recently found that the Neuropeptide B/W contributes to the perception of dominance and is present in neurons that have a limited projection primarily to the amygdala. The present review discusses the specific roles of these neural regions and neurotransmitter systems in the perception of dominance and in hierarchy formation. PMID:26136644

  18. Year-to-year correlations in blood metal levels among individuals of two species of North American sea ducks

    International Nuclear Information System (INIS)

    Wayland, M.; Alisauskas, R.T.; Kellett, D.; Traylor, J.; Swoboda, C.; Neugebauer, E.; Mehl, K.

    2007-01-01

    Sea duck populations have declined in North America. Contaminants, especially metals, have been listed as possible contributing factors. Sea ducks are long-lived. Thus, individuals chronically exposed to elevated metal levels may be at greatest risk. Information about long-term exposure (≥1 year) of individuals to metals is absent. To address this information gap, we examined year-to-year correlations among individual White-Winged Scoters and King Eiders in levels of blood cadmium, lead, mercury and selenium. Positive correlations (r ≥ 0.43), were found in six, five, five and two of seven correlations for cadmium, selenium, lead and mercury. Thus, certain individuals of these species may be exposed over two or more years to higher levels of cadmium, selenium and lead (but apparently not mercury) than other individuals. Single blood samples are appropriate metrics of exposure for studies that examine long-term effects of certain metals on these birds. - Some individuals of two species of sea ducks experience greater long-term (≥1 year) exposure to cadmium, selenium and lead compared to other individuals

  19. Physiological stress responses in wild Asian elephants Elephas maximus in a human-dominated landscape in the Western Ghats, southern India.

    Science.gov (United States)

    Vijayakrishnan, Sreedhar; Kumar, Mavatur Ananda; Umapathy, G; Kumar, Vinod; Sinha, Anindya

    2018-05-16

    Increasing anthropogenic pressures on forests, especially in the tropical regions of the world, have restricted several large mammalian species such as the Asian elephant to fragmented habitats within human-dominated landscapes. In this study, we assessed the effects of an anthropogenic landscape and its associated conflict with humans on the physiological stress responses displayed by Asian elephants in the Anamalai Hills of the Western Ghats mountains in south India. We have quantified faecal glucocorticoid metabolite (FGM) concentrations in focal individual elephants within and across herds, inhabiting both anthropogenic and natural habitats, and evaluated their physiological responses to different socio-ecological situations between November 2013 and April 2014. Physiological stress responses varied significantly among the tested elephant age- and sex categories but not across different types of social organisation. Adults generally showed higher FGM concentrations, even in the absence of stressors, than did any other age category. Males also appeared to have higher stress responses than did females. Although there was no significant variation in mean stress levels between elephants on the plateau in the absence of human interactions and those in adjacent, relatively undisturbed forest habitats, FGM concentrations increased significantly for adult and subadult individuals as well as for calves following drives, during which elephants were driven off aggressively by people. Our study emphasises the general importance of understanding individual variation in physiology and behaviour within a population of a seriously threatened mammalian species, the Asian elephant, and specifically highlights the need for long-term monitoring of the stress physiology and behavioural responses of individual elephants across both human-dominated and natural landscapes. Such studies would not only provide comprehensive insights into the adaptive biology of elephants in changing

  20. Hypothalamic digoxin, hemispheric chemical dominance, and inflammatory bowel disease.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-09-01

    The isoprenoid pathway produces three key metabolites--endogenous digoxin, dolichol, and ubiquinone. It was considered pertinent to assess the pathway in inflammatory bowel disease (ulcerative colitis and regional ileitis). Since endogenous digoxin can regulate neurotransmitter transport, the pathway and the related cascade were also assessed in individuals with differing hemispheric dominance to find out the role of hemispheric dominance in its pathogenesis. All the patients with inflammatory bowel disease were right-handed/left hemispheric dominant by the dichotic listening test. The following parameters were measured in patients with inflammatory bowel disease and in individuals with differing hemispheric dominance: (1) plasma HMG CoA reductase, digoxin, dolichol, ubiquinone, and magnesium levels; (2) tryptophan/tyrosine catabolic patterns; (3) free-radical metabolism; (4) glycoconjugate metabolism; and (5) membrane composition and RBC membrane Na+-K+ ATPase activity. Statistical analysis was done by ANOVA. In patients with inflammatory bowel disease there was elevated digoxin synthesis, increased dolichol and glycoconjugate levels, and low ubiquinone and elevated free radical levels. There was also an increase in tryptophan catabolites and a reduction in tyrosine catabolites. There was an increase in cholesterol:phospholipid ratio and a reduction in glycoconjugate level of RBC membrane in these groups of patients. Inflammatory bowel disease is associated with an upregulated isoprenoid pathway and elevated digoxin secretion from the hypothalamus. This can contribute to immune activation, defective glycoprotein bowel antigen presentation, and autoimmunity and a schizophreniform psychosis important in its pathogenesis. The biochemical patterns obtained in inflammatory bowel disease is similar to those obtained in left-handed/right hemispheric dominant individuals by the dichotic listening test. But all the patients with peptic ulcer disease were right

  1. Hypothalamic digoxin, hemispheric chemical dominance and sarcoidosis.

    Science.gov (United States)

    Ravi Kumar, A; Kurup, Parameswara Achutha

    2004-06-01

    The isoprenoid pathway produces three key metabolites: endogenous digoxin (membrane sodium-potassium ATPase inhibitor, immunomodulator and regulator of neurotransmitter/amino acid transport), dolichol (regulates N-glycosylation of proteins) and ubiquinone (free radical scavenger). The role of the isoprenoid pathway in the pathogenesis of sarcoidosis in relation to hemispheric dominance was studied. The isoprenoid pathway-related cascade was assessed in patients with systemic sarcoidosis with pulmonary involvement. The pathway was also assessed in patients with right hemispheric, left hemispheric and bihemispheric dominance for comparison to find out the role of hemispheric dominance in the pathogenesis of sarcoidosis. In patients with sarcoidosis there was elevated digoxin synthesis, increased dolichol and glycoconjugate levels and low ubiquinone and elevated free radical levels. There was also an increase in tryptophan catabolites and a reduction in tyrosine catabolites. There was an increase in the cholesterol:phospholipid ratio and a reduction in the glycoconjugate level of red blood cell (RBC) membrane in this group of patients. The same biochemical patterns were obtained in individuals with right hemispheric dominance. In individuals with left hemispheric dominance the patterns were reversed. Endogenous digoxin, by activating the calcineurin signal transduction pathway of T cells, can contribute to immune activation in sarcoidosis. An altered glycoconjugate metabolism can lead to the generation of endogenous self-glycoprotein antigens in the lung as well as other tissues. Increased free radical generation can also lead to immune activation. The role of a dysfunctional isoprenoid pathway and endogenous digoxin in the pathogenesis of sarcoidosis in relation to right hemispheric chemical dominance is discussed. All the patients with sarcoidosis were right-handed/left hemispheric dominant according to the dichotic listening test, but their biochemical patterns

  2. Species Diversity and Bird Feed in Residential Complex

    Science.gov (United States)

    Hadinoto; Suhesti, Eni

    2017-12-01

    Bird is one component of the ecosystem which has an important role in supporting the occurrence of an organism's life cycle. Therefore, the presence of birds in an area is important, because it can affect the existence and distribution of plant species. The purpose of this study is to calculate the diversity of bird species and identify the source of bird feed in the compound. This study was conducted by field surveys in the residential complex. In addition to the birds as a research object vegetation as habitat / foraging birds were also observed. Data were analyzed by using the bird diversity index, richenes index, bundance index, dominance analysis, analysis of bird distribution and analysis of the level of meeting types, while vegetation will be analyzed based on the type and part of what is eaten by birds. In Pandau Jaya housing complex, found as many as 12 species of birds which consists of seven families. Bird species often present is Cucak Kutilang (Pycnonotus aurigaster) of 20 individuals, Bondol Peking (Lonchura punctulata) 14 individuals and Perkutut Jawa (Geopelia striata) 10 individuals. Bird species diversity (H ‘) in Pandau Jaya housing complex is still relatively moderate with a value of 2.27, while the Evenness Index (E) of 0.91 and Richenes Index (R) of 2.45. Types of vegetation as a food source, among others: mango, guava, cherry, jackfruit, ketapang, coconut, areca, palm, banana, papaya, flowers and grasses.

  3. Agents with left and right dominant hemispheres and quantum statistics

    Science.gov (United States)

    Ezhov, Alexandr A.; Khrennikov, Andrei Yu.

    2005-01-01

    We present a multiagent model illustrating the emergence of two different quantum statistics, Bose-Einstein and Fermi-Dirac, in a friendly population of individuals with the right-brain dominance and in a competitive population of individuals with the left-brain hemisphere dominance, correspondingly. Doing so, we adduce the arguments that Lefebvre’s “algebra of conscience” can be used in a natural way to describe decision-making strategies of agents simulating people with different brain dominance. One can suggest that the emergence of the two principal statistical distributions is able to illustrate different types of society organization and also to be used in order to simulate market phenomena and psychic disorders, when a switching of hemisphere dominance is involved.

  4. Feral livestock threatens landscapes dominated by columnar cacti

    Science.gov (United States)

    Malo, J. E.; Acebes, P.; Giannoni, S. M.; Traba, J.

    2011-05-01

    The introduction and naturalization of alien species represents a serious threat to many natural protected areas. One such case of worldwide concern is the impact of feral livestock on arid ecosystems. Damage suffered by Echinopsis (= Trichocereus) terscheckii dominating the landscape of rocky slopes was surveyed in seven locations within the Ischigualasto-Talampaya World Heritage Site (Argentina) by measuring the frequency, position on the plant and extent of damage. At the same time we employed transects to estimate the abundance of autochtonous and feral large herbivores ( Lama guanicoe, Bos taurus, Equus asinus) from their dung. Our results show relatively high damage levels (40-77% of individuals damaged, more than 5 dm 3 removed by plant in some sites), particularly within 0.50-1.75 m above the ground, showing herbivores to be the main responsible for them. We also found significant differences between sites in variables measuring damage level and in the intensity of use by the two feral livestock species but not by guanacos. The frequency of damaged cacti below 1.75 m (but not above) was significantly positively correlated among locations with the frequencies of cattle and donkey dung, and the damage suffered by individual cacti was also correlated with donkey and cattle dung in their surroundings after correcting for spatial effects. However, all correlations were non-significant in the case of guanacos. We conclude that the continued presence of feral livestock, particularly donkeys, leads to damages to columnar cacti with potential effects on their populations and the physiognomy of this protected landscape.

  5. On the Informativeness of Dominant and Co-Dominant Genetic Markers for Bayesian Supervised Clustering

    DEFF Research Database (Denmark)

    Guillot, Gilles; Carpentier-Skandalis, Alexandra

    2011-01-01

    We study the accuracy of a Bayesian supervised method used to cluster individuals into genetically homogeneous groups on the basis of dominant or codominant molecular markers. We provide a formula relating an error criterion to the number of loci used and the number of clusters. This formula...

  6. Interactive effects of warming and increased precipitation on community structure and composition in an annual forb dominated desert steppe.

    Directory of Open Access Journals (Sweden)

    Yanhui Hou

    Full Text Available To better understand how warming, increased precipitation and their interactions influence community structure and composition, a field experiment simulating hydrothermal interactions was conducted at an annual forb dominated desert steppe in northern China over 2 years. Increased precipitation increased species richness while warming significantly decreased species richness, and their effects were additive rather than interactive. Although interannual variations in weather conditions may have a major affect on plant community composition on short term experiments, warming and precipitation treatments affected individual species and functional group composition. Warming caused C4 grasses such as Cleistogenes squarrosa to increase while increased precipitation caused the proportions of non-perennial C3 plants like Artemisia capillaris to decrease and perennial C4 plants to increase.

  7. A highly restricted T-cell receptor dominates the CD8+ T-cell response to parvovirus B19 infection in HLA-A*2402-positive individuals

    DEFF Research Database (Denmark)

    Kasprowicz, V; Isa, Adiba; Jeffery, K

    2006-01-01

    Six of seven HLA-A*2402-positive individuals with acute parvovirus B19 infections made vigorous CD8-positive cytotoxic T-cell (CTL) responses to the viral epitope FYTPLADQF. All responders showed highly focused T-cell receptor (TCR) usage, using almost exclusively BV5.1. The BV5.1 TCR dominated...

  8. Social Dominance Orientation, Right-Wing Authoritarianism, and Willingness to Help Addicted Individuals: The Role of Responsibility Judgments

    Directory of Open Access Journals (Sweden)

    Torleif Halkjelsvik

    2014-02-01

    Full Text Available We investigated how Social Dominance Orientation (SDO and Right Wing Authoritarianism (RWA were related to motivation to personally help addicted individuals and approval of public spending on addiction treatment. The study employs an attributional analysis based on Weiner’s theory of social motivation. SDO was associated with less approval of public spending on treatment and lower motivation to personally help. RWA was associated with less approval of public spending but exerted a direct positive effect on motivation to personally help. However, the latter effect was cancelled out by an indirect negative effect from an attributional process where addicted individuals were perceived as more responsible for their condition. An association between RWA and judgments of responsibility was further indicated in an investigation of positive vs. negative outcomes of addictions. RWA correlated with ratings of personal responsibility across the valence of outcomes, whereas SDO did not. In conclusion, the relation between RWA and (lack of motivation to help is partly explained by a greater emphasis on personal responsibility, and the relation between SDO and (lack of motivation to help is independent of responsibility judgments.

  9. Domination, Eternal Domination, and Clique Covering

    Directory of Open Access Journals (Sweden)

    Klostermeyer William F.

    2015-05-01

    Full Text Available Eternal and m-eternal domination are concerned with using mobile guards to protect a graph against infinite sequences of attacks at vertices. Eternal domination allows one guard to move per attack, whereas more than one guard may move per attack in the m-eternal domination model. Inequality chains consisting of the domination, eternal domination, m-eternal domination, independence, and clique covering numbers of graph are explored in this paper.

  10. Distribuição, dominância e estrutura de tamanhos da assembleia de peixes da lagoa Mangueira, sul do Brasil Distribution, dominance and sizes structure of the fish assemblage in the Mangueira lake, southern Brazil

    Directory of Open Access Journals (Sweden)

    Luiz G. S Artioli

    2009-12-01

    écies entre as porções norte e sul da lagoa. As 52 espécies registradas neste estudo representam uma alta riqueza de peixes na lagoa Mangueira, sobretudo quando comparada a outras lagoas costeiras do RS. Padrões diferenciados de composição e abundância de espécies parecem refletir características distintas dos habitats litorâneos amostrados.This study presents the composition of species, the distribution and dominance patterns, and the structure of sizes of the assemblage of fish in distinct habitats (littoral, deeper and near shore limnetic zone of the Mangueira lake, in the southern Brazil. Samples were taken in the north, south and central regions of the lake from 2001 to 2007 using a multi-gear approach (gillnet, cast net, beach seine, dip net and bottom trawling. A total of 52 species were identified, 46 in the littoral zone, 33 in the near shore limnetic zone and 26 in the deep zone, distributed in 17 families, of the which, Characidae, Cichlidae, Loricariidae, and Atherinopsidae were the most diverse. The dominant species summed up 91.1 %, 92.9 % and 82.7 % of the all individuals caught in the littoral, deeper and limnetic zone, respectively. The littoral zone was comprised of small fishes, nearly 70 % between 25 and 50 TL mm. The dominance patterns showed that, in this zone, 19,5 % of the species were dominant, although four of those also prevailed in the other zones. In the deep zone, 7,6% of the captured species were dominant, with similar sizes to the littoral zone. For the other species, the sizes resemble to the near shore limnetic zone. The near shore limnetic zone was comprised of larger fishes, the major part between 150 and 200 TL mm, such as the great characins, the toothless characin and the silverside fishes. A larger difference was observed in the composition of species between the littoral and limnetic zones, with the species Jenynsia multidentata, Bryconamericus iheringii, Hyphessobrycon luetkenii and Gymnogeophagus gymnogenys dominating

  11. Power, Domination and Kafka’s Castle

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    Yücel Karadaş

    2012-12-01

    Full Text Available The propositions of the Enlightenment philosophy, which valued the individual and his/her freedom, began to lose effect in the middle of the 19th century, with the increasing dominance of the ‘social’ and ‘class’ brought about by the growing industrialization. This dominance, which was the result of the modern capitalist society and the beurocratic state power it gave rise to, drove the intellectuals and thinkers of the time to question the individual freedom ideals of the Enlightenment and the early stages of modernity. In the intellectual sphere this questioning gained speed with Marx but became most apparent in the propositions of the Frankfurt School, which showed a lean on Weber’s idea of beurocratic structures of the modern state. Franz Kafka’s The Castle contributes to this questioning from a literary perspective. The Castle is also important because it was written in Germany where the mechanisms of the beurocratic dominance structures were most overt. The novel strikingly represents how these mechanisms of dominance affect the individuals and the relationships between them. This study handles the individual ideal of the Enlightenment and the criticisms directed to this ideal in the modern times, and it analyzes Kafka’s The Castle in terms of how it takes its place among the criticisms to this ideal with a literary dimension. In his famous work Castle, Kafka, evaluate the modern bureaucracy and its impact on the society in a different perspective from Weber who deal with modern society with the context of rationalization. For a better understanding of the novel, it may be necessary to make a double-layer reading of it. Because, until the last pages of the novel, it is thought that modern bureaucracy as a structure is constructed in the context of “nonsense” not “rationality”. The bureucratic mechanism that woven by hundreds of details in the novel, neither its officality nor its domination built on invididuals, and

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

    Science.gov (United States)

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

  13. S-Lagrangian dynamics of many-body systems and behavior of social groups: Dominance and hierarchy formation

    Science.gov (United States)

    Sandler, U.

    2017-11-01

    In this paper, we extend our generalized Lagrangian dynamics (i.e., S-Lagrangian dynamics, which can be applied equally to physical and non-physical systems as per Sandler (2014)) to many-body systems. Unlike common Lagrangian dynamics, this is not a trivial task. For many-body systems with S-dependent Lagrangians, the Lagrangian and the corresponding Hamiltonian or energy become vector functions, conjugated momenta become second-order tensors, and the system inevitably develops a hierarchical structure, even if all bodies initially have similar status and Lagrangians. As an application of our theory, we consider dominance and hierarchy formation, which is present in almost all communities of living species. As a biological basis for this application, we assume that the primary motivation of a groups activity is to attempt to cope with stress arising as pressure from the environment and from intrinsic unmet needs of individuals. It has been shown that the S-Lagrangian approach to a group's evolution naturally leads to formation of linear or despotic dominance hierarchies, depending on differences between individuals in coping with stress. That is, individuals that cope more readily with stress take leadership roles during the evolution. Experimental results in animal groups which support our assumption and findings are considered.

  14. Uropygial gland volatiles may code for olfactory information about sex, individual, and species in Bengalese finches Lonchura striata

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    Jian-Xu ZHANG et al.

    2009-10-01

    Full Text Available Over-shadowed by eye-catching vocal and visual signals, chemical communication has long been overlooked in birds. This study aimed at exploring whether volatile composition of the uropygial gland secretion (UGS of birds was associated with the information about sex, individual and species. By using dichloromethane extraction and gas chromatography-mass spectrometry (GC-MS, we analyzed the UGS volatiles of domesticated Bengalese finches (Lonchura striata, Estrildiea which is also known as white-rumped munias. We characterized 16 volatile molecules from the UGS, including eight n-alkanols, five diesters, an ester, an aldehyde and a fatty acid, and quantified them in terms of GC peak area percentages (relative abundances. Among these compounds, hexadecanol and octadecanol were major components in both sexes. The former was richer in males than females and the latter richer in females than males, suggesting that they might be male and female pheromone candidates, respectively. The high inter-individual variations, in relative abundance, of the UGS volatiles implied that they might carry information about individuality. The similarity between GC profiles of the UGS and wing feather from same individuals indicates that the birds might preen the secretion to their feathers to transmit chemical cues. Additionally, by comparing with three sympatric passerine species,i.e., zebra finches Taeniopygia guttata, yellow-bowed buntings Emberiza chrysophrys and rooks Corvus frugilegus, we found that the composition of C13-C18 alkanols in the UGS might contain information about species. Our study also show that quantitative differences (degree of same UGS volatiles might be the key for the Bengalese finch to code for information about sex and individuality whereas both the kind and degree of UGS constituents could be utilized to code for information about species [Current Zoology 55 (5:–2009].

  15. [Species and size composition of fishes in Barra de Navidad lagoon, Mexican central Pacific].

    Science.gov (United States)

    González-Sansón, Gaspar; Aguilar-Betancourt, Consuelo; Kosonoy-Aceves, Daniel; Lucano-Ramírez, Gabriela; Ruiz-Ramírez, Salvador; Flores-Ortega, Juan Ramón; Hinojosa-Larios, Angel; de Asís Silva-Bátiz, Francisco

    2014-03-01

    Coastal lagoons are considered important nursery areas for many coastal fishes. Barra de Navidad coastal lagoon (3.76km2) is important for local economy as it supports tourism development and artisanal fisheries. However, the role of this lagoon in the dynamics of coastal fish populations is scarcely known. Thus, the objectives of this research were: to characterize the water of the lagoon and related weather conditions, to develop a systematic list of the ichthyofauna, and to estimate the proportion of juveniles in the total number of individuals captured of most abundant species. Water and fish samples were collected between March 2011 and February 2012. Physical and chemical variables were measured in rainy and dry seasons. Several fishing gears were used including a cast net, beach purse seine and gillnets of four different mesh sizes. Our results showed that the lagoon is most of the time euhaline (salinity 30-40ups), although it can be mixopolyhaline (salinity 18-30ups) during short periods. Chlorophyll and nutrients concentrations suggested eutrophication in the lagoon. Mean water temperature changed seasonally from 24.9 degrees C (April, high tide) to 31.4 degrees C (October, low tide). Considering ichthyofauna species, a total of 36 448 individuals of 92 species were collected, 31 of them adding up to 95% of the total of individuals caught. Dominant species were Anchoa spp. (44.6%), Diapterus peruvianus (10.5%), Eucinostomus currani (8.1%), Cetengraulis mysticetus (7.8%), Mugil curema (5.2%) and Opisthonema libertate (4.5%). The lagoon is an important juvenile habitat for 22 of the 31 most abundant species. These included several species of commercial importance such as snappers (Lutjanus argentiventris, L. colorado and L. novemfasciatus), snook (Centropomus nigrescens) and white mullet (Mugil curema). Other four species seem to use the lagoon mainly as adults. This paper is the first contribution on the composition of estuarine ichthyofauna in Jalisco

  16. Genetics Home Reference: autosomal dominant hypocalcemia

    Science.gov (United States)

    ... individuals have features of a kidney disorder called Bartter syndrome in addition to hypocalcemia. These features can include ... sometimes referred to as autosomal dominant hypocalcemia with Bartter syndrome or Bartter syndrome type V. There are two ...

  17. A new species of Bathymedon Sars, 1892 (Amphipoda: Oedicerotidae from the western Mediterranean bathyal floor

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    Damiá Jaume

    1998-12-01

    Full Text Available Bathymedon longirostris sp. nov. (Amphipoda: Oedicerotidae from the western Mediterranean bathyal suprabenthos is described. It is characterised by the well-developed rostrum; the discrete lateral lobe of head; the elongation of the peduncle segment 3 of the first antenna; the very slender propodus of the second gnathopod, which attains maximum width not at the palm angle, but at about midway along the palm margin; and by the relative length of the carpus of the foregoing limb, sub-equal to propodus. The discovery of a tiny remnant of the 2nd peduncle segment of the first antenna in the new species is commented with regard to the homologation of the peduncle segments in other members of the Family. The new taxon was captured below 593 m over muddy bottoms with pteropod shells and remains of planktonic foraminiferans. It was one of the most common amphipods in the lower slope (below ~ 1000 m, whereas in the depth range comprised between 1250 and 1859 m it was the second dominant species, representing 11.4 % of the total gammarideans captured. The area studied harbours three additional congeneric species, although their populations are mainly concentrated in the upper and middle slope. Over the bottom, adult males of the new species apparently tend to occupy higher levels beyond the water-sediment interface than the rest of demographic categories. The gut content of three individuals revealed a bulk of calcified foraminiferans, a diet in consonance with their massive mandibles. Juvenile individuals were more abundant in winter, whereas adult individuals were clearly dominant in summer, thus suggesting the biological cycle of the species follows some type of periodicity.

  18. Integrating plant ecological responses to climate extremes from individual to ecosystem levels.

    Science.gov (United States)

    Felton, Andrew J; Smith, Melinda D

    2017-06-19

    Climate extremes will elicit responses from the individual to the ecosystem level. However, only recently have ecologists begun to synthetically assess responses to climate extremes across multiple levels of ecological organization. We review the literature to examine how plant responses vary and interact across levels of organization, focusing on how individual, population and community responses may inform ecosystem-level responses in herbaceous and forest plant communities. We report a high degree of variability at the individual level, and a consequential inconsistency in the translation of individual or population responses to directional changes in community- or ecosystem-level processes. The scaling of individual or population responses to community or ecosystem responses is often predicated upon the functional identity of the species in the community, in particular, the dominant species. Furthermore, the reported stability in plant community composition and functioning with respect to extremes is often driven by processes that operate at the community level, such as species niche partitioning and compensatory responses during or after the event. Future research efforts would benefit from assessing ecological responses across multiple levels of organization, as this will provide both a holistic and mechanistic understanding of ecosystem responses to increasing climatic variability.This article is part of the themed issue 'Behavioural, ecological and evolutionary responses to extreme climatic events'. © 2017 The Author(s).

  19. The Season for Peace: Reconciliation in a Despotic Species (Lemur catta.

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    Elisabetta Palagi

    Full Text Available However despotic a social group may be, managing conflicts of interest is crucial to preserve group living benefits, mainly based on cooperation. In despotic groups, post-conflict management via reconciliation (the first post-conflict reunion between former opponents can occur, even if conciliatory rates are considerably different. Lemur catta is defined as a despotic species because groups are characterized by a strict linear hierarchy maintained by the adult females (the dominant sex mainly via aggression. Reconciliation was reported in one out of four captive groups of L. catta. Here we investigate which variables influence the occurrence of reconciliation in these despotic groups. We analyzed 2339 Post Conflict (PC-Matched Control (MC observation pairs, collected on eight groups (five in the Berenty forest, Madagascar; three hosted at the Pistoia Zoo, Italy. Since L. catta is characterized by steep female dominance but shows female-female coalitionary support, we expected to confirm the presence of reconciliation in the study species. Consistently, we found reconciliation in one captive group and two wild groups, thus providing the first evidence of the presence of this phenomenon in wild L. catta. Moreover, because this species is a seasonal breeder (with mating occurring once a year, we expected seasonal fluctuations in reconciliation levels. Via a GLMM analysis using data from all wild groups and on a captive group followed for more than one year, we found that season (but not rank; individuals' identity, sex, and age; or group identity significantly affected individual reconciliation rates, and such rates were lowest during the mating period. Thus, reconciliation can be present in groups in which dominants strongly influence and limit social relationships (steep dominance hierarchy except when the advantages of intra-group cooperation are overcome by competition, as occurs in seasonal breeders when reproduction is at stake. We conclude

  20. Jellyfish blooms in China: Dominant species, causes and consequences

    International Nuclear Information System (INIS)

    Dong Zhijun; Liu Dongyan; Keesing, John K.

    2010-01-01

    Three jellyfish species, Aurelia aurita, Cyanea nozakii and Nemopilema nomurai, form large blooms in Chinese seas. We report on the distribution and increasing incidence of jellyfish blooms and their consequences in Chinese coastal seas and analyze their relationship to anthropogenically derived changes to the environment in order to determine the possible causes. A. aurita, C. nozakii and N. nomurai form blooms in the temperate Chinese seas including the northern East China Sea, Yellow Sea and Bohai Sea. N. nomurai forms offshore blooms while the other two species bloom mainly in inshore areas. Eutrophication, overfishing, habitat modification for aquaculture and climate change are all possible contributory factors facilitating plausible mechanisms for the proliferation of jellyfish blooms. In the absence of improvement in coastal marine ecosystem health, jellyfish blooms could be sustained and may even spread from the locations in which they now occur.

  1. Composition, taxonomy and functional diversity of the oropharynx microbiome in individuals with schizophrenia and controls

    Directory of Open Access Journals (Sweden)

    Eduardo Castro-Nallar

    2015-08-01

    Full Text Available The role of the human microbiome in schizophrenia remains largely unexplored. The microbiome has been shown to alter brain development and modulate behavior and cognition in animals through gut-brain connections, and research in humans suggests that it may be a modulating factor in many disorders. This study reports findings from a shotgun metagenomic analysis of the oropharyngeal microbiome in 16 individuals with schizophrenia and 16 controls. High-level differences were evident at both the phylum and genus levels, with Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria dominating both schizophrenia patients and controls, and Ascomycota being more abundant in schizophrenia patients than controls. Controls were richer in species but less even in their distributions, i.e., dominated by fewer species, as opposed to schizophrenia patients. Lactic acid bacteria were relatively more abundant in schizophrenia, including species of Lactobacilli and Bifidobacterium, which have been shown to modulate chronic inflammation. We also found Eubacterium halii, a lactate-utilizing species. Functionally, the microbiome of schizophrenia patients was characterized by an increased number of metabolic pathways related to metabolite transport systems including siderophores, glutamate, and vitamin B12. In contrast, carbohydrate and lipid pathways and energy metabolism were abundant in controls. These findings suggest that the oropharyngeal microbiome in individuals with schizophrenia is significantly different compared to controls, and that particular microbial species and metabolic pathways differentiate both groups. Confirmation of these findings in larger and more diverse samples, e.g., gut microbiome, will contribute to elucidating potential links between schizophrenia and the human microbiota.

  2. Hypothalamic digoxin, hemispheric chemical dominance, and chronic bronchitis emphysema.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-09-01

    The isoprenoid pathway produces three key metabolites--endogenous digoxin (membrane sodium-potassium ATPase inhibitor, immunomodulator, and regulator of neurotransmitter/amino acid transport), dolichol (regulates N-glycosylation of proteins), and ubiquinone (free radical scavenger). This was assessed in patients with chronic bronchitis emphysema. The pathway was also assessed in patients with right hemispheric, left hemispheric, and bihemispheric dominance to find the role of hemispheric dominance in the pathogenesis of chronic bronchitis emphysema. All the 15 patients with chronic bronchitis emphysema were right-handed/left hemispheric dominant by the dichotic listening test. In patients with chronic bronchitis emphysema there was elevated digoxin synthesis, increased dolichol, and glycoconjugate levels, and low ubiquinone and elevated free radical levels. There was also an increase in tryptophan catabolites and a reduction in tyrosine catabolites. There was an increase in cholesterol:phospholipid ratio and a reduction in glycoconjugate levels of RBC membrane in patients with chronic bronchitis emphysema. The same biochemical patterns were obtained in individuals with right hemispheric dominance. Endogenous digoxin by activating the calcineurin signal transduction pathway of T-cell can contribute to immune activation in chronic bronchitis emphysema. Increased free radical generation can also lead to immune activation. Endogenous synthesis of nicotine can contribute to the pathogenesis of the disease. Altered glycoconjugate metabolism and membranogenesis can lead to defective lysosomal stability contributing to the disease process by increased release of lysosomal proteases. The role of an endogenous digoxin and hemispheric dominance in the pathogenesis of chronic bronchitis emphysema and in the regulation of lung structure/function is discussed. The biochemical patterns obtained in chronic bronchitis emphysema is similar to those obtained in left

  3. Spatial Complementarity and the Coexistence of Species

    Science.gov (United States)

    Velázquez, Jorge; Garrahan, Juan P.; Eichhorn, Markus P.

    2014-01-01

    Coexistence of apparently similar species remains an enduring paradox in ecology. Spatial structure has been predicted to enable coexistence even when population-level models predict competitive exclusion if it causes each species to limit its own population more than that of its competitor. Nevertheless, existing hypotheses conflict with regard to whether clustering favours or precludes coexistence. The spatial segregation hypothesis predicts that in clustered populations the frequency of intra-specific interactions will be increased, causing each species to be self-limiting. Alternatively, individuals of the same species might compete over greater distances, known as heteromyopia, breaking down clusters and opening space for a second species to invade. In this study we create an individual-based model in homogeneous two-dimensional space for two putative sessile species differing only in their demographic rates and the range and strength of their competitive interactions. We fully characterise the parameter space within which coexistence occurs beyond population-level predictions, thereby revealing a region of coexistence generated by a previously-unrecognised process which we term the triadic mechanism. Here coexistence occurs due to the ability of a second generation of offspring of the rarer species to escape competition from their ancestors. We diagnose the conditions under which each of three spatial coexistence mechanisms operates and their characteristic spatial signatures. Deriving insights from a novel metric — ecological pressure — we demonstrate that coexistence is not solely determined by features of the numerically-dominant species. This results in a common framework for predicting, given any pair of species and knowledge of the relevant parameters, whether they will coexist, the mechanism by which they will do so, and the resultant spatial pattern of the community. Spatial coexistence arises from complementary combinations of traits in each

  4. Polymorphic DNA microsatellite markers for forensic individual identification and parentage analyses of seven threatened species of parrots (family Psittacidae).

    Science.gov (United States)

    Jan, Catherine; Fumagalli, Luca

    2016-01-01

    The parrot family represents one of the bird group with the largest number of endangered species, as a result of habitat destruction and illegal trade. This illicit traffic involves the smuggling of eggs and animals, and the laundering through captive breeding facilities of wild-caught animals. Despite the huge potential of wildlife DNA forensics to determine with conclusive evidence illegal trade, current usage of DNA profiling approaches in parrots has been limited by the lack of suitable molecular markers specifically developed for the focal species and by low cross-species polymorphism. In this study, we isolated DNA microsatellite markers in seven parrot species threatened with extinction (Amazona brasiliensis, A. oratrix, A. pretrei, A. rhodocorytha, Anodorhynchus leari, Ara rubrogenys and Primolius couloni). From an enriched genomic library followed by 454 pyrosequencing, we characterized a total of 106 polymorphic microsatellite markers (mostly tetranucleotides) in the seven species and tested them across an average number of 19 individuals per species. The mean number of alleles per species and across loci varied from 6.4 to 8.3, with the mean observed heterozygosities ranging from 0.65 to 0.84. Identity and parentage exclusion probabilities were highly discriminatory. The high variability displayed by these microsatellite loci demonstrates their potential utility to perform individual genotyping and parentage analyses, in order to develop a DNA testing framework to determine illegal traffic in these threatened species.

  5. A spatially and temporally explicit, individual-based, life-history and productivity modeling approach for aquatic species

    Science.gov (United States)

    Realized life history expression and productivity in aquatic species, and salmonid fishes in particular, is the result of multiple interacting factors including genetics, habitat, growth potential and condition, and the thermal regime individuals experience, both at critical stag...

  6. Net Primary Production and Carbon Stocks for Subarctic Mesic-Dry Tundras with Contrasting Microtopography, Altitude, and Dominant Species

    DEFF Research Database (Denmark)

    Campioli, Matteo; Michelsen, Anders; Demey, A

    2009-01-01

    Mesic-dry tundras are widespread in the Arctic but detailed assessments of net primary production (NPP) and ecosystem carbon (C) stocks are lacking. We addressed this lack of knowledge by determining the seasonal dynamics of aboveground vascular NPP, annual NPP, and whole-ecosystem C stocks in five...... mesic-dry tundras in Northern Sweden with contrasting microtopography, altitude, and dominant species. Those measurements were paralleled by the stock assessments of nitrogen (N), the limiting nutrient. The vascular production was determined by harvest or in situ growing units, whereas the nonvascular...... hermaphroditum is more productive than Cassiope tetragona vegetation. Although the large majority of the apical NPP occurred in early-mid season (85%), production of stems and evergreen leaves proceeded until about 2 weeks before senescence. Most of the vascular vegetation was belowground (80%), whereas most...

  7. Ash properties of some dominant Greek forest species

    International Nuclear Information System (INIS)

    Liodakis, S.; Katsigiannis, G.; Kakali, G.

    2005-01-01

    The elemental and chemical wood ash compositions of six dominant Greek fuels was investigated using a variety of techniques, including thermal gravimetric analysis (TG), differential thermal analysis (DTA), atomic absorption spectroscopy (AAS) and X-ray diffraction (XRD). In addition, the alkalinity of wood ash was determined by titration. The ash was prepared by combustion at low (600 deg. C), middle (800 deg. C) and high temperatures (1000 deg. C). The ash composition is very important because thousands of hectares of wildlands are burned annually in Greece. The resulting deposits affect soil properties (i.e., pH) and provide a source of inorganic constituents (i.e., Ca, K, Na, Mg, etc.), while the most soluble compounds (i.e., sodium and potassium hydroxides and carbonates) do not persist through the wet season. The samples selected were: Pinus halepensis (Aleppo pine), Pinus brutia (Calabrian pine), Olea europaea (Olive), Cupressus sempervirens (Italian cypress), Pistacia lentiscus (Mastic tree), Quercus coccifera (Holly oak)

  8. Ash properties of some dominant Greek forest species

    Energy Technology Data Exchange (ETDEWEB)

    Liodakis, S. [Laboratory of Inorganic and Analytical Chemistry, Department of Chemical Engineering, National Technical University of Athens (NTUA), 9 Iroon Polytechniou Street, Athens 157 73 (Greece)]. E-mail: liodakis@central.ntua.gr; Katsigiannis, G. [Laboratory of Inorganic and Analytical Chemistry, Department of Chemical Engineering, National Technical University of Athens (NTUA), 9 Iroon Polytechniou Street, Athens 157 73 (Greece); Kakali, G. [Laboratory of Inorganic and Analytical Chemistry, Department of Chemical Engineering, National Technical University of Athens (NTUA), 9 Iroon Polytechniou Street, Athens 157 73 (Greece)

    2005-10-15

    The elemental and chemical wood ash compositions of six dominant Greek fuels was investigated using a variety of techniques, including thermal gravimetric analysis (TG), differential thermal analysis (DTA), atomic absorption spectroscopy (AAS) and X-ray diffraction (XRD). In addition, the alkalinity of wood ash was determined by titration. The ash was prepared by combustion at low (600 deg. C), middle (800 deg. C) and high temperatures (1000 deg. C). The ash composition is very important because thousands of hectares of wildlands are burned annually in Greece. The resulting deposits affect soil properties (i.e., pH) and provide a source of inorganic constituents (i.e., Ca, K, Na, Mg, etc.), while the most soluble compounds (i.e., sodium and potassium hydroxides and carbonates) do not persist through the wet season. The samples selected were: Pinus halepensis (Aleppo pine), Pinus brutia (Calabrian pine), Olea europaea (Olive), Cupressus sempervirens (Italian cypress), Pistacia lentiscus (Mastic tree), Quercus coccifera (Holly oak)

  9. Potential of High-Resolution Satellite Imagery for Mapping Distribution and Evaluating Ecological Characteristics of Tree Species at the Angkor Monument, Cambodia

    Directory of Open Access Journals (Sweden)

    Tomita Mizuki

    2015-01-01

    Full Text Available Large trees play several vital roles in the Angkor monuments landscape. They protect biodiversity, enhance the tourism experience, and provide various ecosystem services to local residents. A clear understanding of forest composition and distribution of individual species, as well as timely monitoring of changes, is necessary for conservation of these trees. using traditional field work, obtaining this sort of data is time-consuming and labour-intensive. This research investigates classification of very high resolution remote sensing data as a tool for efficient analyses. QuickBird satellite imagery was used to clarify the tree species community in and around Preah Khan temple, to elucidate differences in ecological traits among the three dominant species (Dipterocarpus alatus, Lagerstroemia calyculata and Tetrameles nudiflora, and to identify crowns of the dominant species.

  10. Species- and community-level responses combine to drive phenology of lake phytoplankton

    Science.gov (United States)

    Walters, Annika; Sagrario, María de los Ángeles González; Schindler, Daniel E.

    2013-01-01

    Global change is leading to shifts in the seasonal timing of growth and maturation for primary producers. Remote sensing is increasingly used to measure the timing of primary production in both aquatic and terrestrial ecosystems, but there is often a poor correlation between these results and direct observations of life-history responses of individual species. One explanation may be that in addition to phenological shifts, global change is also causing shifts in community composition among species with different seasonal timing of growth and maturation. We quantified how shifts in species phenology and in community composition translated into phenological change in a diverse phytoplankton community from 1962-2000. During this time the aggregate community spring-summer phytoplankton peak has shifted 63 days earlier. The mean taxon shift was only 3 days earlier and shifts in taxa phenology explained only 40% of the observed community phenological shift. The remaining community shift was attributed to dominant early season taxa increasing in abundance while a dominant late season taxon decreased in abundance. In diverse producer communities experiencing multiple stressors, changes in species composition must be considered to fully understand and predict shifts in the seasonal timing of primary production.

  11. Macroalgal-dominated coastal detritic communities from the Western Mediterranean and the Northeastern Atlantic

    Directory of Open Access Journals (Sweden)

    S. JOHER

    2016-07-01

    Full Text Available This is a qualitative comparison of the distribution of macroalgal-dominated coastal detritic communities from the Western Mediterranean and the Northeastern Atlantic, based on our own data from the Balearic Islands (Western Mediterranean and available data from literature. The macroalgal-dominated coastal detritic bottoms from both regions could be distinguished by the presence of a high number of regional exclusive non-carbonated species, and the presence of a high number of maërl-forming species in the Mediterranean. Further, regional differences in the distribution of some exclusive species allowed the distinction of three zones in the Northeastern Atlantic (United Kingdom, French Brittany and Galicia, while no differences were found within the Western Mediterranean. However, the algal communities considered in the selected literature could not be qualitatively distinguished, and all the samples should be considered as maërl beds. Lithothamnion corallioides and Phymatolithon calcareum were the most widespread maërl forming species in the two regions, while in the Western Mediterranean Spongites fruticulosus was also very frequent. According to the differences in the species composition of the basal and erect strata of these beds, and also in their species richness, five different morphologies of macroalgal-dominated detritic bottoms could be distinguished. Their main characteristic species and their biogeographical distribution are detailed.

  12. Work capacity and anticipation in A.A. Ukhtomsky's concept of dominance

    Science.gov (United States)

    Pavlova, L. P.

    2015-08-01

    This paper presents the results of theoretical and experimental investigations of human activity and anticipation based on A.A. Ukhtomsky's concept of brain dominance - a non-equilibrium system-forming factor in living systems. Facts on the stages of dominance formation are presented in relation to the creative abilities of the human brain and the role of fatigue as a "lever" for increasing systems' work capacity on the basis of "trace exaltation". Individually, specific features of dominantogenesis are compared with variations in behavioural types. On the basis of chronotopic EEG analysis, we delineate cortical dominants that underlie individual specifics of cognitive processes. The relation is shown between anticipation and the "expansion of dominants" - the broadening of "distal perception" in time and space, as framed by A.A. Ukhtomsky.

  13. Object-based methods for individual tree identification and tree species classification from high-spatial resolution imagery

    Science.gov (United States)

    Wang, Le

    2003-10-01

    Modern forest management poses an increasing need for detailed knowledge of forest information at different spatial scales. At the forest level, the information for tree species assemblage is desired whereas at or below the stand level, individual tree related information is preferred. Remote Sensing provides an effective tool to extract the above information at multiple spatial scales in the continuous time domain. To date, the increasing volume and readily availability of high-spatial-resolution data have lead to a much wider application of remotely sensed products. Nevertheless, to make effective use of the improving spatial resolution, conventional pixel-based classification methods are far from satisfactory. Correspondingly, developing object-based methods becomes a central challenge for researchers in the field of Remote Sensing. This thesis focuses on the development of methods for accurate individual tree identification and tree species classification. We develop a method in which individual tree crown boundaries and treetop locations are derived under a unified framework. We apply a two-stage approach with edge detection followed by marker-controlled watershed segmentation. Treetops are modeled from radiometry and geometry aspects. Specifically, treetops are assumed to be represented by local radiation maxima and to be located near the center of the tree-crown. As a result, a marker image was created from the derived treetop to guide a watershed segmentation to further differentiate overlapping trees and to produce a segmented image comprised of individual tree crowns. The image segmentation method developed achieves a promising result for a 256 x 256 CASI image. Then further effort is made to extend our methods to the multiscales which are constructed from a wavelet decomposition. A scale consistency and geometric consistency are designed to examine the gradients along the scale-space for the purpose of separating true crown boundary from unwanted

  14. Sneaker "jack" males outcompete dominant "hooknose" males under sperm competition in Chinook salmon (Oncorhynchus tshawytscha).

    Science.gov (United States)

    Young, Brent; Conti, David V; Dean, Matthew D

    2013-12-01

    In a variety of taxa, males deploy alternative reproductive tactics to secure fertilizations. In many species, small "sneaker" males attempt to steal fertilizations while avoiding encounters with larger, more aggressive, dominant males. Sneaker males usually face a number of disadvantages, including reduced access to females and the higher likelihood that upon ejaculation, their sperm face competition from other males. Nevertheless, sneaker males represent an evolutionarily stable strategy under a wide range of conditions. Game theory suggests that sneaker males compensate for these disadvantages by investing disproportionately in spermatogenesis, by producing more sperm per unit body mass (the "fair raffle") and/or by producing higher quality sperm (the "loaded raffle"). Here, we test these models by competing sperm from sneaker "jack" males against sperm from dominant "hooknose" males in Chinook salmon. Using two complementary approaches, we reject the fair raffle in favor of the loaded raffle and estimate that jack males were ∼1.35 times as likely as hooknose males to fertilize eggs under controlled competitive conditions. Interestingly, the direction and magnitude of this skew in paternity shifted according to individual female egg donors, suggesting cryptic female choice could moderate the outcomes of sperm competition in this externally fertilizing species.

  15. Mortality gradients within and among dominant plant populations as barometers of ecosystem change during extreme drought.

    Science.gov (United States)

    Gitlin, Alicyn R; Sthultz, Christopher M; Bowker, Matthew A; Stumpf, Stacy; Paxton, Kristina L; Kennedy, Karla; Muñoz, Axhel; Bailey, Joseph K; Whitham, Thomas G

    2006-10-01

    Understanding patterns of plant population mortality during extreme weather events is important to conservation planners because the frequency of such events is expected to increase, creating the need to integrate climatic uncertainty into management. Dominant plants provide habitat and ecosystem structure, so changes in their distribution can be expected to have cascading effects on entire communities. Observing areas that respond quickly to climate fluctuations provides foresight into future ecological changes and will help prioritize conservation efforts. We investigated patterns of mortality in six dominant plant species during a drought in the southwestern United States. We quantified population mortality for each species across its regional distribution and tested hypotheses to identify ecological stress gradients for each species. Our results revealed three major patterns: (1) dominant species from diverse habitat types (i.e., riparian, chaparral, and low- to high-elevation forests) exhibited significant mortality, indicating that the effects of drought were widespread; (2) average mortality differed among dominant species (one-seed juniper[Juniperus monosperma (Engelm.) Sarg.] 3.3%; manzanita[Arctostaphylos pungens Kunth], 14.6%; quaking aspen[Populus tremuloides Michx.], 15.4%; ponderosa pine[Pinus ponderosa P. & C. Lawson], 15.9%; Fremont cottonwood[Populus fremontii S. Wats.], 20.7%; and pinyon pine[Pinus edulis Engelm.], 41.4%); (3) all dominant species showed localized patterns of very high mortality (24-100%) consistent with water stress gradients. Land managers should plan for climatic uncertainty by promoting tree recruitment in rare habitat types, alleviating unnatural levels of competition on dominant plants, and conserving sites across water stress gradients. High-stress sites, such as those we examined, have conservation value as barometers of change and because they may harbor genotypes that are adapted to climatic extremes.

  16. Hypothalamic digoxin, hemispheric chemical dominance, and oncogenesis: evidence from multiple myeloma.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Paramesware Achutha

    2003-12-01

    This study assessed the changes in the isoprenoid pathway and its metabolites digoxin, dolichol, and ubiquinone in multiple myeloma. The isoprenoid pathway and digoxin status were also studied for comparison in individuals of differing hemispheric dominance to find out the rote of cerebral dominance in the genesis of multiple myeloma and neoplasms. The following parameters were assessed: isoprenoid pathway metabolites, tyrosine and tryptophan catabolites, glycoconjugate metabolism, RBC membrane composition, and free radical metabolism--in multiple myeloma, as well as in individuals of differing hemispheric dominance. There was elevation in plasma HMG CoA reductase activity, serum digoxin, and dolichol, and a reduction in RBC membrane Na(+)-K+ ATPase activity, serum ubiquinone, and magnesium levels. Serum tryptophan, serotonin, nicotine, strychnine, and quinolinic acid were elevated, while tyrosine, dopamine, noradrenaline, and morphine were decreased. The total serum glycosaminoglycans and glycosaminoglycan fractions, the activity of GAG degrading enzymes and glycohydrolases, carbohydrate residues of glycoproteins, and serum glycolipids were elevated. The RBC membrane glycosaminoglycans, hexose, and fucose residues of glycoproteins, cholesterol, and phospholipids were reduced. The activity of all free-radical scavenging enzymes, concentration of glutathione, iron binding capacity, and ceruloplasmin decreased significantly, while the concentration of lipid peroxidation products and nitric oxide increased. Hyperdigoxinemia-related altered intracellular Ca++/Mg++ ratios mediated oncogene activation, dolichol-induced altered glycoconjugate metabolism, and ubiquinone deficiency-related mitochondrial dysfunction can contribute to the pathogenesis of multiple myeloma. The biochemical patterns obtained in multiple myeloma are similar to those obtained in left-handed/right hemispheric chemically dominant individuals by the dichotic listening test. But all the patients with

  17. Domination versus disjunctive domination in graphs | Henning ...

    African Journals Online (AJOL)

    Domination versus disjunctive domination in graphs. Michael A Henning, Sinclair A Marcon. Abstract. A dominating set in a graph G is a set S of vertices of G such that every vertex not in S is adjacent to a vertex of S. The domination number of G is the minimum cardinality of a dominating set of G. For a positive integer b, ...

  18. Fluid Intelligence and Cognitive Reflection in a Strategic Environment: Evidence from Dominance-Solvable Games.

    Science.gov (United States)

    Hanaki, Nobuyuki; Jacquemet, Nicolas; Luchini, Stéphane; Zylbersztejn, Adam

    2016-01-01

    Dominance solvability is one of the most straightforward solution concepts in game theory. It is based on two principles: dominance (according to which players always use their dominant strategy) and iterated dominance (according to which players always act as if others apply the principle of dominance). However, existing experimental evidence questions the empirical accuracy of dominance solvability. In this study, we study the relationships between the key facets of dominance solvability and two cognitive skills, cognitive reflection, and fluid intelligence. We provide evidence that the behaviors in accordance with dominance and one-step iterated dominance are both predicted by one's fluid intelligence rather than cognitive reflection. Individual cognitive skills, however, only explain a small fraction of the observed failure of dominance solvability. The accuracy of theoretical predictions on strategic decision making thus not only depends on individual cognitive characteristics, but also, perhaps more importantly, on the decision making environment itself.

  19. Polymorphic DNA microsatellite markers for forensic individual identification and parentage analyses of seven threatened species of parrots (family Psittacidae

    Directory of Open Access Journals (Sweden)

    Catherine Jan

    2016-09-01

    Full Text Available The parrot family represents one of the bird group with the largest number of endangered species, as a result of habitat destruction and illegal trade. This illicit traffic involves the smuggling of eggs and animals, and the laundering through captive breeding facilities of wild-caught animals. Despite the huge potential of wildlife DNA forensics to determine with conclusive evidence illegal trade, current usage of DNA profiling approaches in parrots has been limited by the lack of suitable molecular markers specifically developed for the focal species and by low cross-species polymorphism. In this study, we isolated DNA microsatellite markers in seven parrot species threatened with extinction (Amazona brasiliensis, A. oratrix, A. pretrei, A. rhodocorytha, Anodorhynchus leari, Ara rubrogenys and Primolius couloni. From an enriched genomic library followed by 454 pyrosequencing, we characterized a total of 106 polymorphic microsatellite markers (mostly tetranucleotides in the seven species and tested them across an average number of 19 individuals per species. The mean number of alleles per species and across loci varied from 6.4 to 8.3, with the mean observed heterozygosities ranging from 0.65 to 0.84. Identity and parentage exclusion probabilities were highly discriminatory. The high variability displayed by these microsatellite loci demonstrates their potential utility to perform individual genotyping and parentage analyses, in order to develop a DNA testing framework to determine illegal traffic in these threatened species.

  20. Species mixing effects on forest productivity in the Netherlands

    NARCIS (Netherlands)

    Lu, Huicui

    2017-01-01

    Many monoculture forests (dominated by a single tree species) have been converted to mixed-species forests (dominated by more than one tree species) in Europe over the last decades. The main reason for this conversion was to increase productivity, including timber production, and enhance other

  1. Hypothalamic digoxin, hemispheric chemical dominance, and eating behavior.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-08-01

    The isoprenoid pathway produces an endogenous membrane Na+-K+ ATPase inhibitor, digoxin, which can regulate neurotransmitter and amino acid transport. Digoxin synthesis and neurotransmitter patterns were assessed in eating disorders. The patterns were compared in those with right hemispheric and left hemispheric dominance. The serum HMG CoA reductase activity, RBC membrane Na+-K+ ATPase activity, serum digoxin, magnesium, tryptophan catabolites (serotonin, quinolinic acid, strychnine, and nicotine), and tyrosine catabolites (morphine, dopamine, and noradrenaline) were measured in anorexia nervosa, bulimia nervosa, right hemispheric dominant, left hemispheric dominant, and bihemispheric dominant individuals. Digoxin synthesis was increased with upregulated tryptophan catabolism and downregulated tyrosine catabolism in those with anorexia nervosa and right hemispheric chemical dominance. Digoxin synthesis was reduced with downregulated tryptophan catabolism and upregulated tyrosine catabolism in those with bulimia nervosa and left hemispheric chemical dominance. The membrane Na+-K+ ATPase activity and serum magnesium were decreased in anorexia nervosa and right hemispheric chemical dominance while they were increased in bulimia nervosa and left hemispheric chemical dominance. Hypothalamic digoxin and hemispheric chemical dominance play a central role in the regulation of eating behavior. Anorexia nervosa represents the right hemispheric chemically dominant/hyperdigoxinemic state and bulimia nervosa the left hemispheric chemically dominant/hypodigoxinemic state.

  2. Predicting invasion in grassland ecosystems: is exotic dominance the real embarrassment of richness?

    Energy Technology Data Exchange (ETDEWEB)

    Seabloom, Eric W. [Department of Ecology, Evolution, and Behavior, University of MN, St. Paul MN 55108 USA; Borer, Elizabeth T. [Department of Ecology, Evolution, and Behavior, University of MN, St. Paul MN 55108 USA; Buckley, Yvonne [ARC Centre of Excellence for Environmental Decisions, School of Biological Sciences, The University of Queensland, Brisbane Queensland 4072 Australia; Cleland, Elsa E. [Ecology, Behavior & Evolution Section, University of California, San Diego La Jolla CA 92093 USA; Davies, Kendi [Department of Ecology and Evolutionary Biology, University of Colorado, Boulder CO 80309 USA; Firn, Jennifer [Queensland University of Technology, Biogeosciences, Brisbane Queensland 4000 Australia; Harpole, W. Stanley [Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames IA 50011 USA; Hautier, Yann [Department of Ecology, Evolution, and Behavior, University of MN, St. Paul MN 55108 USA; Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190 CH-8057 Zurich Switzerland; Lind, Eric [Department of Ecology, Evolution, and Behavior, University of MN, St. Paul MN 55108 USA; MacDougall, Andrew [Department of Integrative Biology, University of Guelph, Guelph Ontario N1G 2W1 Canada; Orrock, John L. [Department of Zoology, University of Wisconsin, Madison WI 53706 USA; Prober, Suzanne M. [CSIRO Ecosystem Sciences, Private Bag 5 Wembley WA 6913 Australia; Adler, Peter [Department of Wildland Resources and the Ecology Center, Utah State University, Logan UT 84322 USA; Alberti, Juan [Instituto de Investigaciones Marinas y Costeras (UNMdP-CONICET), Mar del Plata Argentina; Michael Anderson, T. [Department of Biology, Wake Forest University, Winston-Salem NC 27109 USA; Bakker, Jonathan D. [School of Environmental and Forest Sciences, University of Washington, Seattle WA 98195-4115 USA; Biederman, Lori A. [Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames IA 50011 USA; Blumenthal, Dana [Rangeland Resources Research Unit, USDA Agricultural Research Service, Fort Collins CO 80526 USA; Brown, Cynthia S. [Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins CO 80523 USA; Brudvig, Lars A. [Department of Plant Biology, Michigan State University, East Lansing MI 48824 USA; Caldeira, Maria [Centro de Estudos Florestais, Instituto Superior de Agronomia, Technical University of Lisbon, Lisbon Portugal; Chu, Chengjin [School of Life Sciences, Lanzhou University, Lanzhou 730000 China; Crawley, Michael J. [Department of Biology, Imperial College London, Silwood Park Ascot SL5 7PY UK; Daleo, Pedro [Instituto de Investigaciones Marinas y Costeras (UNMdP-CONICET), Mar del Plata Argentina; Damschen, Ellen I. [Department of Zoology, University of Wisconsin, Madison WI 53706 USA; D' Antonio, Carla M. [Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara CA 93106 USA; DeCrappeo, Nicole M. [U.S. Geological Survey Forest and Rangeland Ecosystem Science Center, Corvallis OR 97331 USA; Dickman, Chris R. [Desert Ecology Research Group, School of Biological Sciences, University of Sydney, Sydney NSW 2006 Australia; Du, Guozhen [School of Life Sciences, Lanzhou University, Lanzhou 730000 China; Fay, Philip A. [USDA-ARS Grassland Soil and Water Research Lab, Temple TX 76502 USA; Frater, Paul [Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames IA 50011 USA; Gruner, Daniel S. [Department of Entomology, University of Maryland, College Park MD 20742 USA; Hagenah, Nicole [School of Life Sciences, University of KwaZulu-Natal, Scottsville Pietermaritzburg 3209 South Africa; Department of Ecology, Evolutionary Biology, Yale University, New Haven CT 06520 USA; Hector, Andrew [Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190 CH-8057 Zurich Switzerland; Helm, Aveliina [Institute of Ecology and Earth Sciences, University of Tartu, Tartu Estonia; Hillebrand, Helmut [Institute for Chemistry and Biology of the Marine Environment, Carl-von-Ossietzky University, Wilhelmshaven Germany; Hofmockel, Kirsten S. [Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames IA 50011 USA; Humphries, Hope C. [INSTAAR, University of Colorado, Boulder CO 80309-0450 USA; Iribarne, Oscar [Instituto de Investigaciones Marinas y Costeras (UNMdP-CONICET), Mar del Plata Argentina; Jin, Virginia L. [USDA-ARS Agroecosystem Management Research Unit, Lincoln NE 68583 USA; Kay, Adam [Biology Department, University of St. Thomas, Saint Paul MN 55105 USA; Kirkman, Kevin P. [School of Life Sciences, University of KwaZulu-Natal, Scottsville Pietermaritzburg 3209 South Africa; Klein, Julia A. [Department Forest, Rangeland & Watershed Stewardship, Colorado State University, Fort Collins CO 80523-1472 USA; Knops, Johannes M. H. [School of Biological Sciences, University of Nebraska, Lincoln NE 68588 USA; La Pierre, Kimberly J. [Department of Ecology, Evolutionary Biology, Yale University, New Haven CT 06520 USA; Ladwig, Laura M. [Department of Biology, University of New Mexico, Albuquerque NM 87103 USA; Lambrinos, John G. [Department of Horticulture, Oregon State University, Corvallis OR 97331 USA; Leakey, Andrew D. B. [Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana IL 61801 USA; Li, Qi [Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008 Qinghai China; Li, Wei [Yunnan Academy of Biodiversity, Southwest Forestry University, Kunming 650224 China; McCulley, Rebecca [Department of Plant & Soil Sciences, University of Kentucky, Lexington KY 40546 USA; Melbourne, Brett [Department of Ecology and Evolutionary Biology, University of Colorado, Boulder CO 80309 USA; Mitchell, Charles E. [Department of Biology, University of North Carolina, Chapel Hill NC 27599 USA; Moore, Joslin L. [Australian Research Centre for Urban Ecology, Melbourne, c/o School of Botany, University of Melbourne, Melbourne Victoria 3010 Australia; Morgan, John [Department of Botany, La Trobe University, Bundoora 3086 Victoria Australia; Mortensen, Brent [Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames IA 50011 USA; O' Halloran, Lydia R. [Department of Zoology, Oregon State University, Corvallis OR 97331 USA; Pärtel, Meelis [Institute of Ecology and Earth Sciences, University of Tartu, Tartu Estonia; Pascual, Jesús [Instituto de Investigaciones Marinas y Costeras (UNMdP-CONICET), Mar del Plata Argentina; Pyke, David A. [U.S. Geological Survey Forest and Rangeland Ecosystem Science Center, Corvallis OR 97331 USA; Risch, Anita C. [Swiss Federal Institute for Forest, Snow and Landscape Research, 8903 Birmensdorf Switzerland; Salguero-Gómez, Roberto [ARC Centre of Excellence for Environmental Decisions, School of Biological Sciences, The University of Queensland, Brisbane Queensland 4072 Australia; Sankaran, Mahesh [National Centre for Biological Sciences, GKVK Campus, Bellary Road Bangalore 560065 India; Schuetz, Martin [Swiss Federal Institute for Forest, Snow and Landscape Research, 8903 Birmensdorf Switzerland; Simonsen, Anna [Department of Ecology & Evolutionary Biology, University of Toronto, Toronto ON M5S 3B2 Canada; Smith, Melinda [Department of Biology, Colorado State University, Fort Collins CO 80523 USA; Stevens, Carly [Lancaster Environment Center, Lancaster University, Lancaster LA1 4YQ UK; Sullivan, Lauren [Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames IA 50011 USA; Wardle, Glenda M. [Desert Ecology Research Group, School of Biological Sciences, University of Sydney, Sydney NSW 2006 Australia; Wolkovich, Elizabeth M. [Biodiversity Research Centre, University of British Columbia, Vancouver V6T 1Z4 Canada; Wragg, Peter D. [Department of Ecology, Evolution, and Behavior, University of MN, St. Paul MN 55108 USA; Wright, Justin [Department of Biology, Duke University, Durham NC 27708 USA; Yang, Louie [Department of Entomology, University of California, Davis CA 95616 USA

    2013-10-16

    Invasions have increased the size of regional species pools, but are typically assumed to reduce native diversity. However, global-scale tests of this assumption have been elusive because of the focus on exotic species richness, rather than relative abundance. This is problematic because low invader richness can indicate invasion resistance by the native community or, alternatively, dominance by a single exotic species. Here, we used a globally replicated study to quantify relationships between exotic richness and abundance in grass-dominated ecosystems in 13 countries on six continents, ranging from salt marshes to alpine tundra. We tested effects of human land use, native community diversity, herbivore pressure, and nutrient limitation on exotic plant dominance. Despite its widespread use, exotic richness was a poor proxy for exotic dominance at low exotic richness, because sites that contained few exotic species ranged from relatively pristine (low exotic richness and cover) to almost completely exotic-dominated ones (low exotic richness but high exotic cover). Both exotic cover and richness were predicted by native plant diversity (native grass richness) and land use (distance to cultivation). Although climate was important for predicting both exotic cover and richness, climatic factors predicting cover (precipitation variability) differed from those predicting richness (maximum temperature and mean temperature in the wettest quarter). Herbivory and nutrient limitation did not predict exotic richness or cover. Exotic dominance was greatest in areas with low native grass richness at the site- or regional-scale. Although this could reflect native grass displacement, a lack of biotic resistance is a more likely explanation, given that grasses comprise the most aggressive invaders. These findings underscore the need to move beyond richness as a surrogate for the extent of invasion, because this metric confounds monodominance with invasion resistance. Monitoring

  3. Social network and dominance hierarchy analyses at Chimpanzee Sanctuary Northwest.

    Directory of Open Access Journals (Sweden)

    Jake A Funkhouser

    Full Text Available Different aspects of sociality bear considerable weight on the individual- and group-level welfare of captive nonhuman primates. Social Network Analysis (SNA is a useful tool for gaining a holistic understanding of the dynamic social relationships of captive primate groups. Gaining a greater understanding of captive chimpanzees through investigations of centrality, preferred and avoided relationships, dominance hierarchy, and social network diagrams can be useful in advising current management practices in sanctuaries and other captive settings. In this study, we investigated the dyadic social relationships, group-level social networks, and dominance hierarchy of seven chimpanzees (Pan troglodytes at Chimpanzee Sanctuary Northwest. We used focal-animal and instantaneous scan sampling to collect 106.75 total hours of associative, affiliative, and agonistic data from June to September 2016. We analyzed our data using SOCPROG to derive dominance hierarchies and network statistics, and we diagrammed the group's social networks in NetDraw. Three individuals were most central in the grooming network, while two others had little connection. Through agonistic networks, we found that group members reciprocally exhibited agonism, and the group's dominance hierarchy was statistically non-linear. One chimpanzee emerged as the most dominant through agonism but was least connected to other group members across affiliative networks. Our results indicate that the conventional methods used to calculate individuals' dominance rank may be inadequate to wholly depict a group's social relationships in captive sanctuary populations. Our results have an applied component that can aid sanctuary staff in a variety of ways to best ensure the improvement of group welfare.

  4. Social network and dominance hierarchy analyses at Chimpanzee Sanctuary Northwest.

    Science.gov (United States)

    Funkhouser, Jake A; Mayhew, Jessica A; Mulcahy, John B

    2018-01-01

    Different aspects of sociality bear considerable weight on the individual- and group-level welfare of captive nonhuman primates. Social Network Analysis (SNA) is a useful tool for gaining a holistic understanding of the dynamic social relationships of captive primate groups. Gaining a greater understanding of captive chimpanzees through investigations of centrality, preferred and avoided relationships, dominance hierarchy, and social network diagrams can be useful in advising current management practices in sanctuaries and other captive settings. In this study, we investigated the dyadic social relationships, group-level social networks, and dominance hierarchy of seven chimpanzees (Pan troglodytes) at Chimpanzee Sanctuary Northwest. We used focal-animal and instantaneous scan sampling to collect 106.75 total hours of associative, affiliative, and agonistic data from June to September 2016. We analyzed our data using SOCPROG to derive dominance hierarchies and network statistics, and we diagrammed the group's social networks in NetDraw. Three individuals were most central in the grooming network, while two others had little connection. Through agonistic networks, we found that group members reciprocally exhibited agonism, and the group's dominance hierarchy was statistically non-linear. One chimpanzee emerged as the most dominant through agonism but was least connected to other group members across affiliative networks. Our results indicate that the conventional methods used to calculate individuals' dominance rank may be inadequate to wholly depict a group's social relationships in captive sanctuary populations. Our results have an applied component that can aid sanctuary staff in a variety of ways to best ensure the improvement of group welfare.

  5. The diminishing dominance of the dominant hemisphere: Language fMRI in focal epilepsy

    Directory of Open Access Journals (Sweden)

    Chris Tailby

    2017-01-01

    Our data highlight the importance of considering language as a complex task where lateralisation varies at the subhemispheric scale. This is especially important for presurgical planning for focal resections where the concept of ‘hemispheric dominance’ may be misleading. This is a precision medicine approach that enables objective evaluation of language dominance within specific brain regions and can reveal surprising and unexpected anomalies that may be clinically important for individual cases.

  6. The Role of Hand Dominance in Beginning Braille Readers

    Science.gov (United States)

    Wright, Tessa

    2009-01-01

    In this article, the author examines the role of "hand dominance" in beginning braille readers. "Hand dominance" refers to whether an individual is "right handed" or "left handed." The data for these analyses were taken from the Alphabetic Braille and Contracted Braille Study (ABC Braille Study). The ABC Braille Study was a five-year nonrandomized…

  7. Limited native plant regeneration in novel, exotic-dominated forests on Hawaii

    Science.gov (United States)

    Joseph Mascaro; Kristen K. Becklund; R. Flint Hughes; Stefan A. Schnitzer

    2008-01-01

    Ecological invasions are amajor driver of global environmental change. When invasions are frequent and prolonged, exotic species can become dominant and ultimately create novel ecosystem types. These ecosystems are now widespread globally. Recent evidence from Puerto Rico suggests that exoticdominated forests can provide suitable regeneration sites for native species...

  8. Individual tree control

    Science.gov (United States)

    Harvey A. Holt

    1989-01-01

    Controlling individual unwanted trees in forest stands is a readily accepted method for improving the value of future harvests. The practice is especially important in mixed hardwood forests where species differ considerably in value and within species individual trees differ in quality. Individual stem control is a mechanical or chemical weeding operation that...

  9. A Social Network Approach Reveals Associations between Mouse Social Dominance and Brain Gene Expression

    Science.gov (United States)

    So, Nina; Franks, Becca; Lim, Sean; Curley, James P.

    2015-01-01

    Modelling complex social behavior in the laboratory is challenging and requires analyses of dyadic interactions occurring over time in a physically and socially complex environment. In the current study, we approached the analyses of complex social interactions in group-housed male CD1 mice living in a large vivarium. Intensive observations of social interactions during a 3-week period indicated that male mice form a highly linear and steep dominance hierarchy that is maintained by fighting and chasing behaviors. Individual animals were classified as dominant, sub-dominant or subordinate according to their David’s Scores and I& SI ranking. Using a novel dynamic temporal Glicko rating method, we ascertained that the dominance hierarchy was stable across time. Using social network analyses, we characterized the behavior of individuals within 66 unique relationships in the social group. We identified two individual network metrics, Kleinberg’s Hub Centrality and Bonacich’s Power Centrality, as accurate predictors of individual dominance and power. Comparing across behaviors, we establish that agonistic, grooming and sniffing social networks possess their own distinctive characteristics in terms of density, average path length, reciprocity out-degree centralization and out-closeness centralization. Though grooming ties between individuals were largely independent of other social networks, sniffing relationships were highly predictive of the directionality of agonistic relationships. Individual variation in dominance status was associated with brain gene expression, with more dominant individuals having higher levels of corticotropin releasing factor mRNA in the medial and central nuclei of the amygdala and the medial preoptic area of the hypothalamus, as well as higher levels of hippocampal glucocorticoid receptor and brain-derived neurotrophic factor mRNA. This study demonstrates the potential and significance of combining complex social housing and intensive

  10. A Social Network Approach Reveals Associations between Mouse Social Dominance and Brain Gene Expression.

    Directory of Open Access Journals (Sweden)

    Nina So

    Full Text Available Modelling complex social behavior in the laboratory is challenging and requires analyses of dyadic interactions occurring over time in a physically and socially complex environment. In the current study, we approached the analyses of complex social interactions in group-housed male CD1 mice living in a large vivarium. Intensive observations of social interactions during a 3-week period indicated that male mice form a highly linear and steep dominance hierarchy that is maintained by fighting and chasing behaviors. Individual animals were classified as dominant, sub-dominant or subordinate according to their David's Scores and I& SI ranking. Using a novel dynamic temporal Glicko rating method, we ascertained that the dominance hierarchy was stable across time. Using social network analyses, we characterized the behavior of individuals within 66 unique relationships in the social group. We identified two individual network metrics, Kleinberg's Hub Centrality and Bonacich's Power Centrality, as accurate predictors of individual dominance and power. Comparing across behaviors, we establish that agonistic, grooming and sniffing social networks possess their own distinctive characteristics in terms of density, average path length, reciprocity out-degree centralization and out-closeness centralization. Though grooming ties between individuals were largely independent of other social networks, sniffing relationships were highly predictive of the directionality of agonistic relationships. Individual variation in dominance status was associated with brain gene expression, with more dominant individuals having higher levels of corticotropin releasing factor mRNA in the medial and central nuclei of the amygdala and the medial preoptic area of the hypothalamus, as well as higher levels of hippocampal glucocorticoid receptor and brain-derived neurotrophic factor mRNA. This study demonstrates the potential and significance of combining complex social housing

  11. Social insect colony as a biological regulatory system: modelling information flow in dominance networks.

    Science.gov (United States)

    Nandi, Anjan K; Sumana, Annagiri; Bhattacharya, Kunal

    2014-12-06

    Social insects provide an excellent platform to investigate flow of information in regulatory systems since their successful social organization is essentially achieved by effective information transfer through complex connectivity patterns among the colony members. Network representation of such behavioural interactions offers a powerful tool for structural as well as dynamical analysis of the underlying regulatory systems. In this paper, we focus on the dominance interaction networks in the tropical social wasp Ropalidia marginata-a species where behavioural observations indicate that such interactions are principally responsible for the transfer of information between individuals about their colony needs, resulting in a regulation of their own activities. Our research reveals that the dominance networks of R. marginata are structurally similar to a class of naturally evolved information processing networks, a fact confirmed also by the predominance of a specific substructure-the 'feed-forward loop'-a key functional component in many other information transfer networks. The dynamical analysis through Boolean modelling confirms that the networks are sufficiently stable under small fluctuations and yet capable of more efficient information transfer compared to their randomized counterparts. Our results suggest the involvement of a common structural design principle in different biological regulatory systems and a possible similarity with respect to the effect of selection on the organization levels of such systems. The findings are also consistent with the hypothesis that dominance behaviour has been shaped by natural selection to co-opt the information transfer process in such social insect species, in addition to its primal function of mediation of reproductive competition in the colony. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  12. Evaluating nurse plants for restoring native woody species to degraded subtropical woodlands.

    Science.gov (United States)

    Yelenik, Stephanie G; DiManno, Nicole; D'Antonio, Carla M

    2015-01-01

    Harsh habitats dominated by invasive species are difficult to restore. Invasive grasses in arid environments slow succession toward more desired composition, yet grass removal exacerbates high light and temperature, making the use of "nurse plants" an appealing strategy. In this study of degraded subtropical woodlands dominated by alien grasses in Hawai'i, we evaluated whether individuals of two native (Dodonaea viscosa, Leptocophylla tameiameia) and one non-native (Morella faya) woody species (1) act as natural nodes of recruitment for native woody species and (2) can be used to enhance survivorship of outplanted native woody species. To address these questions, we quantified the presence and persistence of seedlings naturally recruiting beneath adult nurse shrubs and compared survival and growth of experimentally outplanted seedlings of seven native woody species under the nurse species compared to intact and cleared alien-grass plots. We found that the two native nurse shrubs recruit their own offspring, but do not act as establishment nodes for other species. Morella faya recruited even fewer seedlings than native shrubs. Thus, outplanting will be necessary to increase abundance and diversity of native woody species. Outplant survival was the highest under shrubs compared to away from them with few differences between nurse species. The worst habitat for native seedling survival and growth was within the unmanaged invasive grass matrix. Although the two native nurse species did not differentially affect outplant survival, D. viscosa is the most widespread and easily propagated and is thus more likely to be useful as an initial nurse species. The outplanted species showed variable responses to nurse habitats that we attribute to resource requirements resulting from their typical successional stage and nitrogen fixation capability.

  13. Vulnerability of oak-dominated forests in West Virginia to invasive exotic plants: temporal and spatial patterns of nine exotic species using herbarium records and land classification data

    Science.gov (United States)

    Cynthia D. Huebner

    2003-01-01

    Are oak-dominated forests immune to invasive exotic plants? Herbarium and land classification data were used to evaluate the extent of spread of nine invasive exotic plants and to relate their distributions to remotely-sensed land use types in West Virginia. Collector-defined habitats indicated that the most common habitat was roadsides, but seven of the nine species...

  14. Migration of vascular plant species to a recent wood adjoining ancient woodland

    Directory of Open Access Journals (Sweden)

    Zbigniew Dzwonko

    2014-01-01

    Full Text Available Woodland communities can be restored by natural succession in sites adjoining ancient woodlands which can act as seed sources for trees, shrubs and woodland herbs. The influence of dominant tree species and the distance from an adjacent ancient oak-hornbeam woodland upon the floristic composition of species in a recent pine wood planted on dry rendzina soil were studied. It was found that, in spite of a 52-year long succession, the border between woods was sharp and the composition of species in the recent wood were significantly different than in the adjacent ancient woodland. Canonical correspondence analysis (CCA showed that the distance to the ancient woodland had a significant influence on species distributions in the recent wood. The numbers of species from the Querco-Fagetea class, vegetatively reproducing species and myrmecochores decreased with this distance, whereas the numbers of anemochores increased. The migration rate of many woodland species, calculated on occurrence of the farthest individuals was very slow, varying from 0.0 m year-1 to 0.38 m year-1. The restoration of the field layer vegetation in the studied pine wood was much slower than in recent deciduous woods on rich and moist soils where the migration rate of some species exceeded 1.50 m year-1. Recent woods adjacent to ancient woodlands can be more effectively colonised by woodland species only when they are dominated by broad-leaved trees with quickly decomposing litter, and the spatial continuity of these woods persists for a long period.

  15. On the Dominance of Attitude Emotionality.

    Science.gov (United States)

    Rocklage, Matthew D; Fazio, Russell H

    2016-02-01

    Many situations in our lives require us to make relatively quick decisions as whether to approach or avoid a person or object, buy or pass on a product, or accept or reject an offer. These decisions are particularly difficult when there are both positive and negative aspects to the object. How do people go about navigating this conflict to come to a summary judgment? Using the Evaluative Lexicon (EL), we demonstrate across three studies, 7,700 attitude expressions, and nearly 50 different attitude objects that when positivity and negativity conflict, the valence that is based more on emotion is more likely to dominate. Furthermore, individuals are also more consistent in the expression of their univalent summary judgments when they involve greater emotionality. In sum, valence that is based on emotion tends to dominate when resolving ambivalence and also helps individuals to remain consistent when offering quick judgments. © 2015 by the Society for Personality and Social Psychology, Inc.

  16. Monocular tool control, eye dominance, and laterality in New Caledonian crows.

    Science.gov (United States)

    Martinho, Antone; Burns, Zackory T; von Bayern, Auguste M P; Kacelnik, Alex

    2014-12-15

    Tool use, though rare, is taxonomically widespread, but morphological adaptations for tool use are virtually unknown. We focus on the New Caledonian crow (NCC, Corvus moneduloides), which displays some of the most innovative tool-related behavior among nonhumans. One of their major food sources is larvae extracted from burrows with sticks held diagonally in the bill, oriented with individual, but not species-wide, laterality. Among possible behavioral and anatomical adaptations for tool use, NCCs possess unusually wide binocular visual fields (up to 60°), suggesting that extreme binocular vision may facilitate tool use. Here, we establish that during natural extractions, tool tips can only be viewed by the contralateral eye. Thus, maintaining binocular view of tool tips is unlikely to have selected for wide binocular fields; the selective factor is more likely to have been to allow each eye to see far enough across the midsagittal line to view the tool's tip monocularly. Consequently, we tested the hypothesis that tool side preference follows eye preference and found that eye dominance does predict tool laterality across individuals. This contrasts with humans' species-wide motor laterality and uncorrelated motor-visual laterality, possibly because bill-held tools are viewed monocularly and move in concert with eyes, whereas hand-held tools are visible to both eyes and allow independent combinations of eye preference and handedness. This difference may affect other models of coordination between vision and mechanical control, not necessarily involving tools. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Dispersal, dormancy and life-history tradeoffs at the individual, population and species levels in southern African Asteraceae.

    Science.gov (United States)

    de Waal, Caroli; Anderson, Bruce; Ellis, Allan G

    2016-04-01

    Dispersal and dormancy are important risk-reducing strategies in unpredictable environments. Negative covariation between these strategies is theoretically expected, but empirical evidence is limited and inconsistent. Moreover, covariation may be affected by other life-history traits and may vary across levels of biological organization. We assessed dispersal (vertical fall time of fruits, a proxy for wind dispersal ability) and dormancy (germination fractions measured during germination trials) in populations of 15 annual and 12 perennial wind-dispersed species in six Asteraceae genera from South Africa. Dormancy was higher in annuals than in perennials, whereas fall time was largely determined by evolutionary history. Controlling for phylogeny, dispersal and dormancy was negatively associated across species and life-history categories. Negative covariation between dispersal and dormancy was not evident at either the individual level (except for seed heteromorphic species) or the population level. Our study provides rare empirical support for the theoretical expectation of tradeoffs between dormancy and the alternative risk-reducing strategies, perenniality and dispersal, but refutes the expectation of increased dispersability in perennials. Although negative covariation between dispersal and dormancy at the species level appears not to be a simple consequence of upscaling individual-level mechanistic tradeoffs, our findings suggest that selection for one strategy may constrain evolution of the other. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  18. The Role of Grunt Calls in the Social Dominance Hierarchy of the White-Lipped Peccary (Mammalia, Tayassuidae.

    Directory of Open Access Journals (Sweden)

    Selene S C Nogueira

    Full Text Available Grunt-like calls are present in the vocal repertoire of many group-living mammals and seem to facilitate social interactions between lower and higher-ranking members. The white-lipped peccary (Tayassu pecari lives in stable hierarchical mixed-sex groups and like non-human primates, usually emits grunt-like calls following aggressive interactions, mainly during feeding contexts. We investigated the possible functions of peccaries' grunt-like calls and their relationship to the individuals' social rank, identity, and sexual dimorphism. We observed that low-ranking individuals emitted grunt-like calls more often than high-ranking ones, and that the alpha male never emitted this vocalization. Moreover, the mean minimum frequency of grunt-like calls decreased as the peccary's rank increased. The findings revealed differences among individual grunts, but the low accuracy of cross-validation (16% suggests that individual recognition in peccaries may be less important than an honest signal of individual social status. In addition, the absence of differences in the acoustic parameters of grunt-like calls between males and females points to the lack of sexual dimorphism in this species. We verified that after hearing grunt calls, dominant opponents were more likely to cease attacking a victim, or at least delay the continuation of conflict, probably decreasing the severity of agonistic interactions. Our findings are particularly important to improve the current understanding of the role of grunt-like calls in herd-living mammals with linear dominant hierarchies, and strongly suggest that they are involved in the maintenance of herd social stability and cohesion.

  19. The Role of Grunt Calls in the Social Dominance Hierarchy of the White-Lipped Peccary (Mammalia, Tayassuidae).

    Science.gov (United States)

    Nogueira, Selene S C; Caselli, Christini B; Costa, Thaise S O; Moura, Leiliany N; Nogueira-Filho, Sérgio L G

    2016-01-01

    Grunt-like calls are present in the vocal repertoire of many group-living mammals and seem to facilitate social interactions between lower and higher-ranking members. The white-lipped peccary (Tayassu pecari) lives in stable hierarchical mixed-sex groups and like non-human primates, usually emits grunt-like calls following aggressive interactions, mainly during feeding contexts. We investigated the possible functions of peccaries' grunt-like calls and their relationship to the individuals' social rank, identity, and sexual dimorphism. We observed that low-ranking individuals emitted grunt-like calls more often than high-ranking ones, and that the alpha male never emitted this vocalization. Moreover, the mean minimum frequency of grunt-like calls decreased as the peccary's rank increased. The findings revealed differences among individual grunts, but the low accuracy of cross-validation (16%) suggests that individual recognition in peccaries may be less important than an honest signal of individual social status. In addition, the absence of differences in the acoustic parameters of grunt-like calls between males and females points to the lack of sexual dimorphism in this species. We verified that after hearing grunt calls, dominant opponents were more likely to cease attacking a victim, or at least delay the continuation of conflict, probably decreasing the severity of agonistic interactions. Our findings are particularly important to improve the current understanding of the role of grunt-like calls in herd-living mammals with linear dominant hierarchies, and strongly suggest that they are involved in the maintenance of herd social stability and cohesion.

  20. Prolonged Permian Triassic ecological crisis recorded by molluscan dominance in Late Permian offshore assemblages.

    Science.gov (United States)

    Clapham, Matthew E; Bottjer, David J

    2007-08-07

    The end-Permian mass extinction was the largest biotic crisis in the history of animal life, eliminating as many as 95% of all species and dramatically altering the ecological structure of marine communities. Although the causes of this pronounced ecosystem shift have been widely debated, the broad consensus based on inferences from global taxonomic diversity patterns suggests that the shift from abundant brachiopods to dominant molluscs was abrupt and largely driven by the catastrophic effects of the end-Permian mass extinction. Here we analyze relative abundance counts of >33,000 fossil individuals from 24 silicified Middle and Late Permian paleocommunities, documenting a substantial ecological shift to numerical dominance by molluscs in the Late Permian, before the major taxonomic shift at the end-Permian mass extinction. This ecological change was coincident with the development of fluctuating anoxic conditions in deep marine basins, suggesting that numerical dominance by more tolerant molluscs may have been driven by variably stressful environmental conditions. Recognition of substantial ecological deterioration in the Late Permian also implies that the end-Permian extinction was the climax of a protracted environmental crisis. Although the Late Permian shift to molluscan dominance was a pronounced ecological change, quantitative counts of 847 Carboniferous-Cretaceous collections from the Paleobiology Database indicate that it was only the first stage in a stepwise transition that culminated with the final shift to molluscan dominance in the Late Jurassic. Therefore, the ecological transition from brachiopods to bivalves was more protracted and complex than their simple Permian-Triassic switch in diversity.

  1. Prolonged Permian–Triassic ecological crisis recorded by molluscan dominance in Late Permian offshore assemblages

    Science.gov (United States)

    Clapham, Matthew E.; Bottjer, David J.

    2007-01-01

    The end-Permian mass extinction was the largest biotic crisis in the history of animal life, eliminating as many as 95% of all species and dramatically altering the ecological structure of marine communities. Although the causes of this pronounced ecosystem shift have been widely debated, the broad consensus based on inferences from global taxonomic diversity patterns suggests that the shift from abundant brachiopods to dominant molluscs was abrupt and largely driven by the catastrophic effects of the end-Permian mass extinction. Here we analyze relative abundance counts of >33,000 fossil individuals from 24 silicified Middle and Late Permian paleocommunities, documenting a substantial ecological shift to numerical dominance by molluscs in the Late Permian, before the major taxonomic shift at the end-Permian mass extinction. This ecological change was coincident with the development of fluctuating anoxic conditions in deep marine basins, suggesting that numerical dominance by more tolerant molluscs may have been driven by variably stressful environmental conditions. Recognition of substantial ecological deterioration in the Late Permian also implies that the end-Permian extinction was the climax of a protracted environmental crisis. Although the Late Permian shift to molluscan dominance was a pronounced ecological change, quantitative counts of 847 Carboniferous–Cretaceous collections from the Paleobiology Database indicate that it was only the first stage in a stepwise transition that culminated with the final shift to molluscan dominance in the Late Jurassic. Therefore, the ecological transition from brachiopods to bivalves was more protracted and complex than their simple Permian–Triassic switch in diversity. PMID:17664426

  2. When does "economic man" dominate social behavior?

    Science.gov (United States)

    Camerer, Colin F; Fehr, Ernst

    2006-01-06

    The canonical model in economics considers people to be rational and self-regarding. However, much evidence challenges this view, raising the question of when "Economic Man" dominates the outcome of social interactions, and when bounded rationality or other-regarding preferences dominate. Here we show that strategic incentives are the key to answering this question. A minority of self-regarding individuals can trigger a "noncooperative" aggregate outcome if their behavior generates incentives for the majority of other-regarding individuals to mimic the minority's behavior. Likewise, a minority of other-regarding individuals can generate a "cooperative" aggregate outcome if their behavior generates incentives for a majority of self-regarding people to behave cooperatively. Similarly, in strategic games, aggregate outcomes can be either far from or close to Nash equilibrium if players with high degrees of strategic thinking mimic or erase the effects of others who do very little strategic thinking. Recently developed theories of other-regarding preferences and bounded rationality explain these findings and provide better predictions of actual aggregate behavior than does traditional economic theory.

  3. Genetic variation in foundation species governs the dynamics of trophic interactions

    Science.gov (United States)

    Valencia-Cuevas, Leticia; Mussali-Galante, Patricia; Cano-Santana, Zenón; Pujade-Villar, Juli; Equihua-Martínez, Armando

    2018-01-01

    Abstract Various studies have demonstrated that the foundation species genetic diversity can have direct effects that extend beyond the individual or population level, affecting the dependent communities. Additionally, these effects may be indirectly extended to higher trophic levels throughout the entire community. Quercus castanea is an oak species with characteristics of foundation species beyond presenting a wide geographical distribution and being a dominant element of Mexican temperate forests. In this study, we analyzed the influence of population (He) and individual (HL) genetic diversity of Q. castanea on its canopy endophagous insect community and associated parasitoids. Specifically, we studied the composition, richness (S) and density of leaf-mining moths (Lepidoptera: Tischeridae, Citheraniidae), gall-forming wasps (Hymenoptera: Cynipidae), and canopy parasitoids of Q. castanea. We sampled 120 trees belonging to six populations (20/site) through the previously recognized gradient of genetic diversity. In total, 22 endophagous insect species belonging to three orders (Hymenoptera, Lepidoptera, and Diptera) and 20 parasitoid species belonging to 13 families were identified. In general, we observed that the individual genetic diversity of the host plant (HL) has a significant positive effect on the S and density of the canopy endophagous insect communities. In contrast, He has a significant negative effect on the S of endophagous insects. Additionally, indirect effects of HL were observed, affecting the S and density of parasitoid insects. Our results suggest that genetic variation in foundation species can be one of the most important factors governing the dynamics of tritrophic interactions that involve oaks, herbivores, and parasitoids. PMID:29492034

  4. Hypothalamic-mediated model for systemic lupus erythematosis: relation to hemispheric chemical dominance.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-11-01

    The isoprenoid pathway including endogenous digoxin was assessed in systemic lupus erythematosis (SLE). All the patients with SLE were right-handed/left hemispheric dominant by the dichotic listening test. This was also studied for comparison in patients with right hemispheric and left hemispheric dominance. The isoprenoid pathway was upregulated with increased digoxin synthesis in patients with SLE and in those with right hemispheric dominance. In this group of patients (i) the tryptophan catabolites were increased and the tyrosine catabolites reduced, (ii) the dolichol and glycoconjugate levels were elevated, (iii) lysosomal stability was reduced, (iv) ubiquinone levels were low and free radical levels increased, and (v) the membrane cholesterol:phospholipid ratios were increased and membrane glycoconjugates reduced. On the other hand, in patients with left hemispheric dominance the reverse patterns were obtained. The biochemical patterns obtained in SLE is similar to those obtained in left-handed/right hemispheric chemically dominant individuals. But all the patients with SLE were right-handed/left hemispheric dominant by the dichotic listening test. Hemispheric chemical dominance has no correlation with handedness or the dichotic listening test. SLE occurs in right hemispheric chemically dominant individuals, and is a reflection of altered brain function. The role of the isoprenoid pathway in the pathogenesis of SLE and its relation to hemispheric dominance is discussed.

  5. Sibling rivalry: training effects, emergence of dominance and incomplete control.

    Science.gov (United States)

    Benhaiem, Sarah; Hofer, Heribert; Kramer-Schadt, Stephanie; Brunner, Edgar; East, Marion L

    2012-09-22

    Within-brood or -litter dominance provides fitness-related benefits if dominant siblings selfishly skew access to food provided by parents in their favour. Models of facultative siblicide assume that dominants exert complete control over their subordinate sibling's access to food and that control is maintained, irrespective of the subordinate's hunger level. By contrast, a recent functional hypothesis suggests that subordinates should contest access to food when the cost of not doing so is high. Here, we show that within spotted hyena (Crocuta crocuta) twin litters, dominants most effectively skew access to maternal milk in their favour when their aggression prompts a highly submissive response. When hungry, subordinates were less submissive in response to aggression, thereby decreasing lost suckling time and increasing suckling time lost by dominants. In a species where adult females socially dominate adult males, juvenile females were more often dominant than males in mixed-sex litters, and subordinate sisters used more effective counter-tactics against dominant brothers than subordinate brothers against dominant sisters. Our results provide, to our knowledge, the first evidence in a mammal that dominant offspring in twin litters do not exert complete control over their sibling's access to resources (milk), and that sibling dominance relationships are influenced by sibling sex and training effects.

  6. Bulk viscous matter-dominated Universes: asymptotic properties

    Energy Technology Data Exchange (ETDEWEB)

    Avelino, Arturo [Departamento de Física, Campus León, Universidad de Guanajuato, León, Guanajuato (Mexico); García-Salcedo, Ricardo [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada - Legaria del IPN, México D.F. (Mexico); Gonzalez, Tame [Departamento de Ingeniería Civil, División de Ingeniería, Universidad de Guanajuato, Guanajuato (Mexico); Nucamendi, Ulises [Instituto de Física y Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio C-3, Ciudad Universitaria, CP. 58040 Morelia, Michoacán (Mexico); Quiros, Israel, E-mail: avelino@fisica.ugto.mx, E-mail: rigarcias@ipn.mx, E-mail: tamegc72@gmail.com, E-mail: ulises@ifm.umich.mx, E-mail: iquiros6403@gmail.com [Departamento de Matemáticas, Centro Universitario de Ciencias Exactas e Ingenierías (CUCEI), Corregidora 500 S.R., Universidad de Guadalajara, 44420 Guadalajara, Jalisco (Mexico)

    2013-08-01

    By means of a combined use of the type Ia supernovae and H(z) data tests, together with the study of the asymptotic properties in the equivalent phase space — through the use of the dynamical systems tools — we demonstrate that the bulk viscous matter-dominated scenario is not a good model to explain the accepted cosmological paradigm, at least, under the parametrization of bulk viscosity considered in this paper. The main objection against such scenarios is the absence of conventional radiation and matter-dominated critical points in the phase space of the model. This entails that radiation and matter dominance are not generic solutions of the cosmological equations, so that these stages can be implemented only by means of unique and very specific initial conditions, i. e., of very unstable particular solutions. Such a behavior is in marked contradiction with the accepted cosmological paradigm which requires of an earlier stage dominated by relativistic species, followed by a period of conventional non-relativistic matter domination, during which the cosmic structure we see was formed. Also, we found that the bulk viscosity is positive just until very late times in the cosmic evolution, around z < 1. For earlier epochs it is negative, been in tension with the local second law of thermodynamics.

  7. Self-reinforcing dominance interactions between virtual males and females. Hypothesis generation for primate studies

    NARCIS (Netherlands)

    Hemelrijk, C.K.

    2000-01-01

    Although in group-living primates an individual's dominance position is a consequence of its social skills with both sexes, there are few data and hardly any theory on male-female dominance relationships. In order to stimulate a systematic study on this topic, I present a simple individual-oriented

  8. Population structure and fruit availability of the babassu palm ( Attalea speciosa Mart. ex Spreng in human-dominated landscapes of the Northeast Region of Brazil

    Directory of Open Access Journals (Sweden)

    Juliana Loureiro Almeida Campos

    Full Text Available ABSTRACT We studied the population structure and fruit availability of the babassu palm, Attalea speciosa, in three human-dominated landscapes located near a rural community in the region of Araripe, in the Northeast Region of Brazil, that were under intense fruit harvest. Fifty 10 x 10 m plots were randomly established in each of the three landscapes, and all individuals of A. speciosa within the plots were classified as seedlings, juveniles or adults, with the height of all adult individuals being measured. An additional 20 individuals were marked in each landscape, and the number of total bunches, fruits per bunch and bunches per palm tree were recorded. The populations of A. speciosa in the three landscapes exhibited an inverted J-shape plot, but pasture and shifting cultivation possessed a significantly higher number of individuals, seedlings and adults than the seasonal semideciduous forest, plus they possessed a greater seedling/adult ratio. Shifting cultivation was found to be favorable for fructification. The present study found that shifting cultivation and pastures are landscape practices that can contribute to the rapid expansion and establishment of A. speciosa, which can become a dominant species in the region of Araripe.

  9. A dominant EV71-specific CD4+ T cell epitope is highly conserved among human enteroviruses.

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    Ruicheng Wei

    Full Text Available CD4+ T cell-mediated immunity plays a central role in determining the immunopathogenesis of viral infections. However, the role of CD4+ T cells in EV71 infection, which causes hand, foot and mouth disease (HFMD, has yet to be elucidated. We applied a sophisticated method to identify promiscuous CD4+ T cell epitopes contained within the sequence of the EV71 polyprotein. Fifteen epitopes were identified, and three of them are dominant ones. The most dominant epitope is highly conserved among enterovirus species, including HFMD-related coxsackieviruses, HFMD-unrelated echoviruses and polioviruses. Furthermore, the CD4+ T cells specific to the epitope indeed cross-reacted with the homolog of poliovirus 3 Sabin. Our findings imply that CD4+ T cell responses to poliovirus following vaccination, or to other enteroviruses to which individuals may be exposed in early childhood, may have a modulating effect on subsequent CD4+ T cell response to EV71 infection or vaccine.

  10. Insights on plant interaction between dominating species from patterns of plant association

    DEFF Research Database (Denmark)

    Damgaard, Christian; Ehlers, Bodil K.; Ransijn, Johannes C.G.

    2018-01-01

    Abstract It has been suggested that in order to infer ecological processes from observed patterns of species abundance we need to investigate the covariance in species abundance. Consequently, an expression for the expected covariance of pin-point cover measurements of two speciesisdeveloped.By c...

  11. Ecomorphological correlates of twenty dominant fish species of Amazonian floodplain lakes

    Directory of Open Access Journals (Sweden)

    F. K. Siqueira-Souza

    Full Text Available Abstract Fishes inhabiting Amazonian floodplain lakes exhibits a great variety of body shape, which was a key advantage to colonize the several habitats that compose these areas adjacent to the large Amazon rivers. In this paper, we did an ecomorphological analysis of twenty abundant species, sampled in May and August 2011, into two floodplain lakes of the lower stretch of the Solimões River. The analysis detected differences among species, which could be probably associated with swimming ability and habitat use preferences.

  12. Optimum water depth ranges of dominant submersed macrophytes in a natural freshwater lake.

    Science.gov (United States)

    Ye, Bibi; Chu, Zhaosheng; Wu, Aiping; Hou, Zeying; Wang, Shengrui

    2018-01-01

    Macrophytes show a zonal distribution along the lake littoral zone because of their specific preferred water depths while the optimum growth water depths of dominant submersed macrophytes in natural lakes are not well known. We studied the seasonal biomass and frequency patterns of dominant and companion submersed macrophytes along the water depth gradient in Lake Erhai in 2013. The results showed that the species richness and community biomass showed hump-back shaped patterns along the water depth gradient both in polydominant and monodominant communities. Biomass percentage of Potamogenton maackianus showed a hump-back pattern while biomass percentages of Ceratophyllum demersum and Vallisneria natans appeared U-shaped patterns across the water depth gradient in polydominant communities whereas biomass percentage of V. natans increased with the water depth in monodominant communities. Dominant species demonstrated a broader distribution range of water depth than companion species. Frequency and biomass of companion species declined drastically with the water depth whereas those of dominant species showed non-linear patterns across the water depth gradient. Namely, along the water depth gradient, biomass of P. maackianus and V. natans showed hump-back patterns and biomasses of C. demersum displayed a U-shaped pattern in the polydominant communities but biomass of V. natans demonstrated a hump-back pattern in the monodominant communities; frequency of P. maackianus showed a hump-back pattern and C. demersum and V. natans maintained high frequencies in the two types of communities. We can speculate that in Lake Erhai the optimum growth water depths of P. maackianus and C. demersum in the polydominant communities are 2.5-4.5 m and 1-2 m or 5-6 m, respectively and that of V. natans is 3-5 m in the polydominant communities and 2.5-5 m in the monodominant communities. This is the first report that the optimum water depth ranges in the horizontal direction of three

  13. Growth Responses of Three Dominant Wetland Plant Species to Various Flooding and Nutrient Levels

    Science.gov (United States)

    Barrett, S.; Shaffer, G. P.

    2017-12-01

    Coastal Louisiana is experiencing a greater rate of wetland loss than any other wetland system in the United States. This is primarily due to anthropogenic stressors such as flood control levees, backfilling and development of wetlands, and other hydrologic modifications. Methods employed to mitigate wetland loss include the construction of river diversions and assimilation wetlands, which can provide consistent sources of freshwater influx and nutrients to impounded swamps and marshes. It is well known that prolonged flooding causes strain on wetland plant communities and facilitates or exacerbates wetland degradation. However, because river diversions and assimilation wetlands bring high nutrient loads along with freshwater, there is debate over whether prolonged flooding or high influx of nutrients is the primary cause of stress in river diversion and assimilation wetland discharge areas. This mesocosm experiment addresses this question by isolating the effects of flooding and nutrients on the biomass of baldcypress (Taxodium distichum), maidencane (Panicum hemitomon), and cordgrass (Spartina patens) over the course of a growing season. The results of this study provide clarity as to whether flooding stress, high nutrient loads, or both cause a reduction in wetland plant productivity. By evaluating the growth responses of T. distichum, P. hemitomon, and S. patens at varying nutrient regimes, we gain insight on how these more dominant species will react to high nutrient discharges from large river diversions, such as those proposed in Louisiana's 2017 Master Plan.

  14. Mediterranean species of Caulerpa are polyploid with smaller genomes in the invasive ones.

    Directory of Open Access Journals (Sweden)

    Elena Varela-Álvarez

    Full Text Available Caulerpa species are marine green algae, which often act as invasive species with rapid clonal proliferation when growing outside their native biogeographical borders. Despite many publications on the genetics and ecology of Caulerpa species, their life history and ploidy levels are still to be resolved and are the subject of large controversy. While some authors claimed that the thallus found in nature has a haplodiplobiontic life cycle with heteromorphic alternation of generations, other authors claimed a diploid or haploid life cycle with only one generation involved. DAPI-staining with image analysis and microspectrophotometry were used to estimate relative nuclear DNA contents in three species of Caulerpa from the Mediterranean, at individual, population and species levels. Results show that ploidy levels and genome size vary in these three Caulerpa species, with a reduction in genome size for the invasive ones. Caulerpa species in the Mediterranean are polyploids in different life history phases; all sampled C. taxifolia and C. racemosa var. cylindracea were in haplophasic phase, but in C. prolifera, the native species, individuals were found in both diplophasic and haplophasic phases. Different levels of endopolyploidy were found in both C. prolifera and C. racemosa var. cylindracea. Life history is elucidated for the Mediterranean C. prolifera and it is hypothesized that haplophasic dominance in C. racemosa var. cylindracea and C. taxifolia is a beneficial trait for their invasive strategies.

  15. Evaluating nurse plants for restoring native woody species to degraded subtropical woodlands

    Science.gov (United States)

    Yelenik, Stephanie G.; DiManno, Nicole; D’Antonio, Carla M.

    2015-01-01

    Harsh habitats dominated by invasive species are difficult to restore. Invasive grasses in arid environments slow succession toward more desired composition, yet grass removal exacerbates high light and temperature, making the use of “nurse plants” an appealing strategy. In this study of degraded subtropical woodlands dominated by alien grasses in Hawai'i, we evaluated whether individuals of two native (Dodonaea viscosa, Leptocophylla tameiameia) and one non-native (Morella faya) woody species (1) act as natural nodes of recruitment for native woody species and (2) can be used to enhance survivorship of outplanted native woody species. To address these questions, we quantified the presence and persistence of seedlings naturally recruiting beneath adult nurse shrubs and compared survival and growth of experimentally outplanted seedlings of seven native woody species under the nurse species compared to intact and cleared alien-grass plots. We found that the two native nurse shrubs recruit their own offspring, but do not act as establishment nodes for other species. Morella faya recruited even fewer seedlings than native shrubs. Thus, outplanting will be necessary to increase abundance and diversity of native woody species. Outplant survival was the highest under shrubs compared to away from them with few differences between nurse species. The worst habitat for native seedling survival and growth was within the unmanaged invasive grass matrix. Although the two native nurse species did not differentially affect outplant survival, D. viscosa is the most widespread and easily propagated and is thus more likely to be useful as an initial nurse species. The outplanted species showed variable responses to nurse habitats that we attribute to resource requirements resulting from their typical successional stage and nitrogen fixation capability.

  16. Juvenile greylag geese (Anser anser discriminate between individual siblings.

    Directory of Open Access Journals (Sweden)

    Isabella B R Scheiber

    Full Text Available Social species that maintain individualised relationships with certain others despite continuous changes in age, reproductive status and dominance rank between group members ought to be capable of individual recognition. Tests of "true" individual recognition, where an individual recognises unique features of another, are rare, however. Often kinship and/or familiarity suffice to explain dyadic interactions. The complex relationships within a greylag goose flock suggest that they should be able to recognise individuals irrespective of familiarity or kinship. We tested whether six-week-old hand-raised greylags can discriminate between two of their siblings. We developed a new experimental protocol, in which geese were trained to associate social siblings with geometrical symbols. Subsequently, focals were presented with two geometrical symbols in the presence of a sibling associated with one of the symbols. Significant choice of the geometrical symbol associated with the target present indicated that focals were able to distinguish between individual targets. Greylag goslings successfully learned this association-discrimination task, regardless of genetic relatedness or sex of the sibling targets. Social relationships within a goose flock thus may indeed be based on recognition of unique features of individual conspecifics.

  17. Sneaker “jack” males outcompete dominant “hooknose” males under sperm competition in Chinook salmon (Oncorhynchus tshawytscha)

    Science.gov (United States)

    Young, Brent; Conti, David V; Dean, Matthew D

    2013-01-01

    In a variety of taxa, males deploy alternative reproductive tactics to secure fertilizations. In many species, small “sneaker” males attempt to steal fertilizations while avoiding encounters with larger, more aggressive, dominant males. Sneaker males usually face a number of disadvantages, including reduced access to females and the higher likelihood that upon ejaculation, their sperm face competition from other males. Nevertheless, sneaker males represent an evolutionarily stable strategy under a wide range of conditions. Game theory suggests that sneaker males compensate for these disadvantages by investing disproportionately in spermatogenesis, by producing more sperm per unit body mass (the “fair raffle”) and/or by producing higher quality sperm (the “loaded raffle”). Here, we test these models by competing sperm from sneaker “jack” males against sperm from dominant “hooknose” males in Chinook salmon. Using two complementary approaches, we reject the fair raffle in favor of the loaded raffle and estimate that jack males were ∼1.35 times as likely as hooknose males to fertilize eggs under controlled competitive conditions. Interestingly, the direction and magnitude of this skew in paternity shifted according to individual female egg donors, suggesting cryptic female choice could moderate the outcomes of sperm competition in this externally fertilizing species. PMID:24455130

  18. A Lactobacillus-Deficient Vaginal Microbiota Dominates Postpartum Women in Rural Malawi

    Science.gov (United States)

    2018-01-01

    ABSTRACT The bacterial community found in the vagina is an important determinant of a woman's health and disease status. A healthy vaginal microbiota is associated with low species richness and a high proportion of one of a number of different Lactobacillus spp. When disrupted, the resulting abnormal vaginal microbiota is associated with a number of disease states and poor pregnancy outcomes. Studies up until now have concentrated on relatively small numbers of American and European populations that may not capture the full complexity of the community or adequately predict what constitutes a healthy microbiota in all populations. In this study, we sampled and characterized the vaginal microbiota found on vaginal swabs taken postpartum from a cohort of 1,107 women in rural Malawi. We found a population dominated by Gardnerella vaginalis and devoid of the most common vaginal Lactobacillus species, even if the vagina was sampled over a year postpartum. This Lactobacillus-deficient anaerobic community, commonly labeled community state type (CST) 4, could be subdivided into four further communities. A Lactobacillus iners-dominated vaginal microbiota became more common the longer after delivery the vagina was sampled, but G. vaginalis remained the dominant organism. These results outline the difficulty in all-encompassing definitions of what a healthy or abnormal postpartum vaginal microbiota is. Previous identification of community state types and associations among bacterial species, bacterial vaginosis, and adverse birth outcomes may not represent the complex heterogeneity of the microbiota present. (This study has been registered at ClinicalTrials.gov as NCT01239693.) IMPORTANCE A bacterial community in the vaginal tract is dominated by a small number of Lactobacillus species, and when not present there is an increased incidence of inflammatory conditions and adverse birth outcomes. A switch to a vaginal bacterial community lacking in Lactobacillus species is common

  19. Lactobacillus-deficient vaginal microbiota dominate post-partum women in rural Malawi.

    Science.gov (United States)

    Doyle, Ronan; Gondwe, Austridia; Fan, Yue-Mei; Maleta, Kenneth; Ashorn, Per; Klein, Nigel; Harris, Kathryn

    2018-01-05

    The bacterial community found in the vagina is an important determinant of a woman's health and disease. A healthy vaginal microbiota is associated with a lower species richness and high proportions of one of a number of different Lactobacillus spp.. When disrupted the resulting abnormal vaginal microbiota is associated with a number of disease states and poor pregnancy outcomes. Studies up until now have concentrated on relatively small numbers of American and European populations which may not capture the full complexity of the community, nor adequately predict what constitutes a healthy microbiota in all populations. In this study we sampled and characterised the vaginal microbiota from a cohort of 1107 women in rural Malawi found on vaginal swabs taken post-partum. We found a population dominated by Gardnerella vaginalis and devoid of the most common vaginal Lactobacillus species, even if the vagina was sampled over a year post-partum. The Lactobacillus -deficient anaerobic community commonly labelled community state type (CST) 4 could be sub-divided into four further communities. A Lactobacillus iners dominated vaginal microbiota became more common the longer after delivery the vagina was sampled, but G. vaginalis remained the dominant organism. These results outline the difficulty in all-encompassing definitions of what a healthy or abnormal vaginal microbiota is post-partum. Previous identification of community state types and associations between bacterial species, bacterial vaginosis and adverse birth outcomes may not represent the complex heterogeneity of the microbiota present. Importance A bacterial community in the vaginal tract that is dominated by small number of bacterial Lactobacillus species and when they are not present, there is a greater incidence of inflammatory conditions and adverse birth outcomes. A switch to a vaginal bacterial community lacking in Lactobacillus species is common after pregnancy. In this study we characterised the vaginal

  20. Plant water use characteristics of five dominant shrub species of the Lower Rio Grande Valley, Texas, USA: implications for shrubland restoration and conservation.

    Science.gov (United States)

    Adhikari, Arjun; White, Joseph D

    2014-01-01

    The biogeographic distribution of plant species is inherently associated with the plasticity of physiological adaptations to environmental variation. For semi-arid shrublands with a legacy of saline soils, characterization of soil water-tolerant shrub species is necessary for habitat restoration given future projection of increased drought magnitude and persistence in these ecosystems. Five dominant native shrub species commonly found in the Lower Rio Grande Valley, TX, USA, were studied, namely Acacia farnesiana, Celtis ehrenbergiana, Forestiera angustifolia, Parkinsonia aculeata and Prosopis glandulosa. To simulate drought conditions, we suspended watering of healthy, greenhouse-grown plants for 4 weeks. Effects of soil salinity were also studied by dosing plants with 10% NaCl solution with suspended watering. For soil water deficit treatment, the soil water potential of P. glandulosa was the highest (-1.20 MPa), followed by A. farnesiana (-4.69 MPa), P. aculeata (-5.39 MPa), F. angustifolia (-6.20 MPa) and C. ehrenbergiana (-10.02 MPa). For the soil salinity treatment, P. glandulosa also had the highest soil water potential value (-1.60 MPa), followed by C. ehrenbergiana (-1.70 MPa), A. farnesiana (-1.84 MPa), P. aculeata (-2.04 MPa) and F. angustifolia (-6.99 MPa). Within the species, only C. ehrenbergiana and F. angustifolia for soil water deficit treatment and A. farnesiana for the salinity treatment had significantly lower soil water potential after 4 weeks of treatment (P < 0.05). We found that soil water potential, stomatal conductance and net photosynthesis of the species significantly reduced over time for both treatments (P < 0.05). We conclude that while all species exhibited capacities to withstand current water availability, some species demonstrated limited tolerance for extreme water stress that may be important for management of future shrub diversity in Lower Rio Grande Valley.

  1. Linking Keystone Species and Functional Groups: A New Operational Definition of the Keystone Species Concept

    OpenAIRE

    Robert D. Davic

    2003-01-01

    The concept of the "keystone species" is redefined to allow for the a priori prediction of these species within ecosystems. A keystone species is held to be a strongly interacting species whose top-down effect on species diversity and competition is large relative to its biomass dominance within a functional group. This operational definition links the community importance of keystone species to a specific ecosystem process, e.g., the regulation of species diversity, within functional groups ...

  2. Do Interspecific Differences in Sapling Growth Traits Contribute to the Co-dominance of Acer saccharum and Fagus grandifolia?

    Science.gov (United States)

    Takahashi, Koichi; Lechowicz, Martin J.

    2008-01-01

    Background and Aims Acer saccharum and Fagus grandifolia are among the most dominant late-successional tree species in North America. The influence of sapling growth responses to canopy gaps on the co-dominance of the two species in an old-growth forest in southern Quebec, Canada was examined. Two predictions were evaluated: (a) F. grandifolia is more shade tolerant than A. saccharum due to greater sapling leaf area and net production per sapling in closed-canopy conditions; and (b) the height growth rate of A. saccharum in canopy gaps is greater than that of F. grandifolia due to increased net production per sapling. Methods Sapling crown allometry, net production and height growth rates were compared between and within the two species in closed canopy vs. canopy gaps. Standardized major axis regression was used to analyse differences in crown allometry. Key Results F. grandifolia had greater crown projection, sapling leaf area and net production rate per sapling than A. saccharum in closed-canopy conditions. In response to canopy gaps, net production per sapling increased to the same degree in both species. The net production per sapling of F. grandifolia thus was much greater than that of A. saccharum in both canopy gap and closed-canopy conditions. The height growth rate of both species increased in canopy gaps, but the degree of increase was greater in F. grandifolia than in A. saccharum. Conclusions F. grandifolia regenerated more successfully than A. saccharum in both closed-canopy conditions and canopy gaps, which indicates that the co-dominance of the two species cannot be maintained simply by interspecific differences in shade tolerance and growth in gaps. Previous research showed that although Fagus and Acer shared dominance at this site, their relative dominance shifted with edaphic conditions. This suggests that the widespread co-dominance of the two species in eastern North American forests is maintained by the joint influence of canopy disturbance

  3. Photosynthesis in Hydrogen-Dominated Atmospheres

    Science.gov (United States)

    Bains, William; Seager, Sara; Zsom, Andras

    2014-01-01

    The diversity of extrasolar planets discovered in the last decade shows that we should not be constrained to look for life in environments similar to early or present-day Earth. Super-Earth exoplanets are being discovered with increasing frequency, and some will be able to retain a stable, hydrogen-dominated atmosphere. We explore the possibilities for photosynthesis on a rocky planet with a thin H2-dominated atmosphere. If a rocky, H2-dominated planet harbors life, then that life is likely to convert atmospheric carbon into methane. Outgassing may also build an atmosphere in which methane is the principal carbon species. We describe the possible chemical routes for photosynthesis starting from methane and show that less energy and lower energy photons could drive CH4-based photosynthesis as compared with CO2-based photosynthesis. We find that a by-product biosignature gas is likely to be H2, which is not distinct from the hydrogen already present in the environment. Ammonia is a potential biosignature gas of hydrogenic photosynthesis that is unlikely to be generated abiologically. We suggest that the evolution of methane-based photosynthesis is at least as likely as the evolution of anoxygenic photosynthesis on Earth and may support the evolution of complex life. PMID:25411926

  4. Photosynthesis in Hydrogen-Dominated Atmospheres

    Directory of Open Access Journals (Sweden)

    William Bains

    2014-11-01

    Full Text Available The diversity of extrasolar planets discovered in the last decade shows that we should not be constrained to look for life in environments similar to early or present-day Earth. Super-Earth exoplanets are being discovered with increasing frequency, and some will be able to retain a stable, hydrogen-dominated atmosphere. We explore the possibilities for photosynthesis on a rocky planet with a thin H2-dominated atmosphere. If a rocky, H2-dominated planet harbors life, then that life is likely to convert atmospheric carbon into methane. Outgassing may also build an atmosphere in which methane is the principal carbon species. We describe the possible chemical routes for photosynthesis starting from methane and show that less energy and lower energy photons could drive CH4-based photosynthesis as compared with CO2-based photosynthesis. We find that a by-product biosignature gas is likely to be H2, which is not distinct from the hydrogen already present in the environment. Ammonia is a potential biosignature gas of hydrogenic photosynthesis that is unlikely to be generated abiologically. We suggest that the evolution of methane-based photosynthesis is at least as likely as the evolution of anoxygenic photosynthesis on Earth and may support the evolution of complex life.

  5. Diversity and biomass of native macrophytes are negatively related to dominance of an invasive Poaceae in Brazilian sub-tropical streams

    Directory of Open Access Journals (Sweden)

    Luiz Felipe Gonçalves Fernandes

    2013-06-01

    Full Text Available Besides exacerbated exploitation, pollution, flow alteration and habitats degradation, freshwater biodiversity is also threatened by biological invasions. This paper addresses how native aquatic macrophyte communities are affected by the non-native species Urochloa arrecta, a current successful invader in Brazilian freshwater systems. We compared the native macrophytes colonizing patches dominated and non-dominated by this invader species. We surveyed eight streams in Northwest Paraná State (Brazil. In each stream, we recorded native macrophytes' richness and biomass in sites where U. arrecta was dominant and in sites where it was not dominant or absent. No native species were found in seven, out of the eight investigated sites where U. arrecta was dominant. Thus, we found higher native species richness, Shannon index and native biomass values in sites without dominance of U. arrecta than in sites dominated by this invader. Although difficult to conclude about causes of such differences, we infer that the elevated biomass production by this grass might be the primary reason for alterations in invaded environments and for the consequent impacts on macrophytes' native communities. However, biotic resistance offered by native richer sites could be an alternative explanation for our results. To mitigate potential impacts and to prevent future environmental perturbations, we propose mechanical removal of the invasive species and maintenance or restoration of riparian vegetation, for freshwater ecosystems have vital importance for the maintenance of ecological services and biodiversity and should be preserved.

  6. Total Domination Versus Paired-Domination in Regular Graphs

    Directory of Open Access Journals (Sweden)

    Cyman Joanna

    2018-05-01

    Full Text Available A subset S of vertices of a graph G is a dominating set of G if every vertex not in S has a neighbor in S, while S is a total dominating set of G if every vertex has a neighbor in S. If S is a dominating set with the additional property that the subgraph induced by S contains a perfect matching, then S is a paired-dominating set. The domination number, denoted γ(G, is the minimum cardinality of a dominating set of G, while the minimum cardinalities of a total dominating set and paired-dominating set are the total domination number, γt(G, and the paired-domination number, γpr(G, respectively. For k ≥ 2, let G be a connected k-regular graph. It is known [Schaudt, Total domination versus paired domination, Discuss. Math. Graph Theory 32 (2012 435–447] that γpr(G/γt(G ≤ (2k/(k+1. In the special case when k = 2, we observe that γpr(G/γt(G ≤ 4/3, with equality if and only if G ≅ C5. When k = 3, we show that γpr(G/γt(G ≤ 3/2, with equality if and only if G is the Petersen graph. More generally for k ≥ 2, if G has girth at least 5 and satisfies γpr(G/γt(G = (2k/(k + 1, then we show that G is a diameter-2 Moore graph. As a consequence of this result, we prove that for k ≥ 2 and k ≠ 57, if G has girth at least 5, then γpr(G/γt(G ≤ (2k/(k +1, with equality if and only if k = 2 and G ≅ C5 or k = 3 and G is the Petersen graph.

  7. Self-organizing dominance hierarchies in a wild primate population

    OpenAIRE

    Franz, Mathias; McLean, Emily; Tung, Jenny; Altmann, Jeanne; Alberts, Susan C.

    2015-01-01

    Linear dominance hierarchies, which are common in social animals, can profoundly influence access to limited resources, reproductive opportunities and health. In spite of their importance, the mechanisms that govern the dynamics of such hierarchies remain unclear. Two hypotheses explain how linear hierarchies might emerge and change over time. The ‘prior attributes hypothesis’ posits that individual differences in fighting ability directly determine dominance ranks. By contrast, the ‘social d...

  8. Strong Regionality and Dominance of Anaerobic Bacterial Taxa Characterize Diazotrophic Bacterial Communities of the Arcto-Alpine Plant Species Oxyria digyna and Saxifraga oppositifolia

    Directory of Open Access Journals (Sweden)

    Manoj Kumar

    2017-10-01

    Full Text Available Arctic and alpine biomes are most often strongly nitrogen-limited, and hence biological nitrogen fixation is a strong driver of these ecosystems. Both biomes are characterized by low temperatures and short growing seasons, but they differ in seasonality of solar radiation and in soil water balance due to underlying permafrost in the Arctic. Arcto-alpine plant species are well-adapted to the low temperatures that prevail in their habitats, and plant growth is mainly limited by the availability of nutrients, in particular nitrogen, due to slow mineralization. Nitrogen fixing bacteria are likely important for plant growth in these habitats, but very little is known of these bacteria or forces shaping their communities. In this study, we characterized the potential nitrogen fixing bacterial (PNFB communities associated with two arcto-alpine pioneer plant species, Oxyria digyna (mountain sorrel and Saxifraga oppositifolia (blue saxifrage, in three climate regions. Both of these plants readily colonize low nutrient mineral soils. Our goal was to investigate how climate (region and, on the other hand, host plant and plant species shape these communities. To our knowledge, this is the first comprehensive study describing PNFB communities associated with pioneer plants in different arcto-alpine biomes. Replicate samples were taken from two arctic regions, Kilpisjärvi and Ny-Ålesund, and one alpine region, Mayrhofen. In these, the PNFB communities in the bulk and rhizosphere soils and the plant endospheres were characterized by nifH-targeted PCR and massive parallel sequencing. The data revealed strong effects of climatic region on the dominating nitrogen fixers. Specifically, nifH sequences related to Geobacter (δ-Proteobacteria were present in high relative abundances in the nitrogen-fixing communities in the Mayrhofen and Kilpisjärvi regions, while members of the Clostridiales prevailed in the Kilpisjärvi and Ny-Ålesund regions. The bulk and

  9. Strong Regionality and Dominance of Anaerobic Bacterial Taxa Characterize Diazotrophic Bacterial Communities of the Arcto-Alpine Plant Species Oxyria digyna and Saxifraga oppositifolia.

    Science.gov (United States)

    Kumar, Manoj; van Elsas, Jan Dirk; Nissinen, Riitta

    2017-01-01

    Arctic and alpine biomes are most often strongly nitrogen-limited, and hence biological nitrogen fixation is a strong driver of these ecosystems. Both biomes are characterized by low temperatures and short growing seasons, but they differ in seasonality of solar radiation and in soil water balance due to underlying permafrost in the Arctic. Arcto-alpine plant species are well-adapted to the low temperatures that prevail in their habitats, and plant growth is mainly limited by the availability of nutrients, in particular nitrogen, due to slow mineralization. Nitrogen fixing bacteria are likely important for plant growth in these habitats, but very little is known of these bacteria or forces shaping their communities. In this study, we characterized the potential nitrogen fixing bacterial (PNFB) communities associated with two arcto-alpine pioneer plant species, Oxyria digyna (mountain sorrel) and Saxifraga oppositifolia (blue saxifrage), in three climate regions. Both of these plants readily colonize low nutrient mineral soils. Our goal was to investigate how climate (region) and, on the other hand, host plant and plant species shape these communities. To our knowledge, this is the first comprehensive study describing PNFB communities associated with pioneer plants in different arcto-alpine biomes. Replicate samples were taken from two arctic regions, Kilpisjärvi and Ny-Ålesund, and one alpine region, Mayrhofen. In these, the PNFB communities in the bulk and rhizosphere soils and the plant endospheres were characterized by nifH -targeted PCR and massive parallel sequencing. The data revealed strong effects of climatic region on the dominating nitrogen fixers. Specifically, nifH sequences related to Geobacter (δ- Proteobacteria ) were present in high relative abundances in the nitrogen-fixing communities in the Mayrhofen and Kilpisjärvi regions, while members of the Clostridiales prevailed in the Kilpisjärvi and Ny-Ålesund regions. The bulk and rhizosphere soil

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

    OpenAIRE

    Bo Terning Hansen; Tore Slagsvold

    2004-01-01

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

  11. Transcending Cognitive Individualism

    Science.gov (United States)

    Zerubavel, Eviatar; Smith, Eliot R.

    2010-01-01

    Advancing knowledge in many areas of psychology and neuroscience, underlined by dazzling images of brain scans, appear to many professionals and to the public to show that people are on the way to explaining cognition purely in terms of processes within the individual's head. Yet while such cognitive individualism still dominates the popular…

  12. Filament identification and dominance of Eikelboom Type 0092 in ...

    African Journals Online (AJOL)

    In order of prevalence, the five most common dominant filament species in 96 activated sludge samples were: Eikelboom Type 0092, Eikelboom Type 1851, nocardioforms, Microthrix parvicella and Eikelboom Type 021N. In order to compile a statistically significant database, it is recommended that an extensive nationwide ...

  13. A generic individual-based model to simulate morphogenesis, C-N acquisition and population dynamics in contrasting forage legumes.

    Science.gov (United States)

    Louarn, Gaëtan; Faverjon, Lucas

    2018-04-18

    Individual-based models (IBMs) are promising tools to disentangle plant interactions in multi-species grasslands and foster innovative species mixtures. This study describes an IBM dealing with the morphogenesis, growth and C-N acquisition of forage legumes that integrates plastic responses from functional-structural plant models. A generic model was developed to account for herbaceous legume species with contrasting above- and below-ground morphogenetic syndromes and to integrate the responses of plants to light, water and N. Through coupling with a radiative transfer model and a three-dimensional virtual soil, the model allows dynamic resolution of competition for multiple resources at individual plant level within a plant community. The behaviour of the model was assessed on a range of monospecific stands grown along gradients of light, water and N availability. The model proved able to capture the diversity of morphologies encountered among the forage legumes. The main density-dependent features known about even-age plant populations were correctly anticipated. The model predicted (1) the 'reciprocal yield' law relating average plant mass to density, (2) a self-thinning pattern close to that measured for herbaceous species and (3) consistent changes in the size structure of plant populations with time and pedo-climatic conditions. In addition, plastic changes in the partitioning of dry matter, the N acquisition mode and in the architecture of shoots and roots emerged from the integration of plant responses to their local environment. This resulted in taller plants and thinner roots when competition was dominated by light, and shorter plants with relatively more developed root systems when competition was dominated by soil resources. A population dynamic model considering growth and morphogenesis responses to multiple resources heterogeneously distributed in the environment was presented. It should allow scaling plant-plant interactions from individual to

  14. Genome Reduction in Psychromonas Species within the Gut of an Amphipod from the Ocean’s Deepest Point

    KAUST Repository

    Zhang, Weipeng

    2018-04-25

    Amphipods are the dominant scavenging metazoan species in the Mariana Trench, the deepest known point in Earth\\'s oceans. Here the gut microbiota of the amphipod Hirondellea gigas collected from the Challenger and Sirena Deeps of the Mariana Trench were investigated. The 11 amphipod individuals included for analyses were dominated by Psychromonas, of which a nearly complete genome was successfully recovered (designated CDP1). Compared with previously reported free-living Psychromonas strains, CDP1 has a highly reduced genome. Genome alignment showed deletion of the trimethylamine N-oxide (TMAO) reducing gene cluster in CDP1, suggesting that the

  15. Genome Reduction in Psychromonas Species within the Gut of an Amphipod from the Ocean’s Deepest Point

    KAUST Repository

    Zhang, Weipeng; Tian, Ren-Mao; Sun, Jin; Bougouffa, Salim; Ding, Wei; Cai, Lin; Lan, Yi; Tong, Haoya; Li, Yongxin; Jamieson, Alan J.; Bajic, Vladimir B.; Drazen, Jeffrey C.; Bartlett, Douglas; Qian, Pei-Yuan

    2018-01-01

    Amphipods are the dominant scavenging metazoan species in the Mariana Trench, the deepest known point in Earth's oceans. Here the gut microbiota of the amphipod Hirondellea gigas collected from the Challenger and Sirena Deeps of the Mariana Trench were investigated. The 11 amphipod individuals included for analyses were dominated by Psychromonas, of which a nearly complete genome was successfully recovered (designated CDP1). Compared with previously reported free-living Psychromonas strains, CDP1 has a highly reduced genome. Genome alignment showed deletion of the trimethylamine N-oxide (TMAO) reducing gene cluster in CDP1, suggesting that the

  16. Social dominance, values and ideological positioning in college students

    Directory of Open Access Journals (Sweden)

    Elena Zubieta

    2015-09-01

    Full Text Available Social Dominance Theory (Sidanius & Pratto, 1999 stress that systematic inter group discrimination is related to social ideologies that contribute to coordinate institutions and individuals behaviors. The acceptance of inequity legitimating ideologies is partially determined for individuals general desire of group based domination. This desire is captured by Social Orientation Domination construct -SDO. Pursuing the objective of exploring SDO levels and its relationship with variables such ideological positioning and values, a descriptive correlation study, with a non experimental design, was carried out based on a convenience sample composed by 254 college students from Buenos Aires city surroundings . Results show that SDO is positively associated with Power and Achievement values and negatively with Benevolence and Universalism. SDO is stronger in participants right side ideologically positioned. Participants show a low SDO, emphasize self- trascendence and openness to change values and tend to a left side ideological positioning. Age, participant’s quality of “students” and prevailed career orientation can be seen as factors conditioning a more hierarchies attenuating believes and behaviors. 

  17. Identifying keystone species in the human gut microbiome from metagenomic timeseries using sparse linear regression.

    Directory of Open Access Journals (Sweden)

    Charles K Fisher

    Full Text Available Human associated microbial communities exert tremendous influence over human health and disease. With modern metagenomic sequencing methods it is now possible to follow the relative abundance of microbes in a community over time. These microbial communities exhibit rich ecological dynamics and an important goal of microbial ecology is to infer the ecological interactions between species directly from sequence data. Any algorithm for inferring ecological interactions must overcome three major obstacles: 1 a correlation between the abundances of two species does not imply that those species are interacting, 2 the sum constraint on the relative abundances obtained from metagenomic studies makes it difficult to infer the parameters in timeseries models, and 3 errors due to experimental uncertainty, or mis-assignment of sequencing reads into operational taxonomic units, bias inferences of species interactions due to a statistical problem called "errors-in-variables". Here we introduce an approach, Learning Interactions from MIcrobial Time Series (LIMITS, that overcomes these obstacles. LIMITS uses sparse linear regression with boostrap aggregation to infer a discrete-time Lotka-Volterra model for microbial dynamics. We tested LIMITS on synthetic data and showed that it could reliably infer the topology of the inter-species ecological interactions. We then used LIMITS to characterize the species interactions in the gut microbiomes of two individuals and found that the interaction networks varied significantly between individuals. Furthermore, we found that the interaction networks of the two individuals are dominated by distinct "keystone species", Bacteroides fragilis and Bacteroided stercosis, that have a disproportionate influence on the structure of the gut microbiome even though they are only found in moderate abundance. Based on our results, we hypothesize that the abundances of certain keystone species may be responsible for individuality in

  18. The socio-matrix reloaded: from hierarchy to dominance profile in wild lemurs.

    Science.gov (United States)

    Norscia, Ivan; Palagi, Elisabetta

    2015-01-01

    Dominance hierarchy influences the life quality of social animals, and its definition should in principle be based on the outcome of agonistic interactions. However, defining and comparing the dominance profile of social groups is difficult due to the different dominance measures used and because no one measure explains it all. We applied different analytical methods to winner-loser sociomatrices to determine the dominance profile of five groups of wild lemurs (species: Lemur catta, Propithecus verreauxi, and Eulemur rufus x collaris) from the Berenty forest (Madagascar). They are an excellent study model because they share the same habitat and an apparently similar dominance profile: linear hierarchy and female dominance. Data were collected over more than 1200 h of observation. Our approach included four steps: (1) by applying the binary dyadic dominance relationship method (I&SI) on either aggressions or supplant sociomatrices we verified whether hierarchy was aggression or submission based; (2) by calculating normalized David's scores and measuring steepness from aggression sociomatrices we evaluated whether hierarchy was shallow or steep; (3) by comparing the ranking orders obtained with methods 1 and 2 we assessed whether hierarchy was consistent or not; and (4) by assessing triangle transitivity and comparing it with the linearity index and the level of group cohesion we determined if hierarchy was more or less cohesive. Our results show that L. catta groups have got a steep, consistent, highly transitive and cohesive hierarchy. P. verreauxi groups are characterized by a moderately steep and consistent hierarchy, with variable levels of triangle transitivity and cohesion. E. rufus x collaris group possesses a shallow and inconsistent hierarchy, with lower (but not lowest) levels of transitivity and cohesion. A multiple analytical approach on winner-loser sociomatrices other than leading to an in-depth description of the dominance profile, allows intergroup

  19. The socio-matrix reloaded: from hierarchy to dominance profile in wild lemurs

    Directory of Open Access Journals (Sweden)

    Ivan Norscia

    2015-01-01

    Full Text Available Dominance hierarchy influences the life quality of social animals, and its definition should in principle be based on the outcome of agonistic interactions. However, defining and comparing the dominance profile of social groups is difficult due to the different dominance measures used and because no one measure explains it all. We applied different analytical methods to winner-loser sociomatrices to determine the dominance profile of five groups of wild lemurs (species: Lemur catta, Propithecus verreauxi, and Eulemur rufus x collaris from the Berenty forest (Madagascar. They are an excellent study model because they share the same habitat and an apparently similar dominance profile: linear hierarchy and female dominance. Data were collected over more than 1200 h of observation. Our approach included four steps: (1 by applying the binary dyadic dominance relationship method (I&SI on either aggressions or supplant sociomatrices we verified whether hierarchy was aggression or submission based; (2 by calculating normalized David’s scores and measuring steepness from aggression sociomatrices we evaluated whether hierarchy was shallow or steep; (3 by comparing the ranking orders obtained with methods 1 and 2 we assessed whether hierarchy was consistent or not; and (4 by assessing triangle transitivity and comparing it with the linearity index and the level of group cohesion we determined if hierarchy was more or less cohesive. Our results show that L. catta groups have got a steep, consistent, highly transitive and cohesive hierarchy. P. verreauxi groups are characterized by a moderately steep and consistent hierarchy, with variable levels of triangle transitivity and cohesion. E. rufus x collaris group possesses a shallow and inconsistent hierarchy, with lower (but not lowest levels of transitivity and cohesion. A multiple analytical approach on winner-loser sociomatrices other than leading to an in-depth description of the dominance profile

  20. Children and adults use physical size and numerical alliances in third-party judgments of dominance

    Directory of Open Access Journals (Sweden)

    Stella F Lourenco

    2016-01-01

    Full Text Available Humans and other social animals interact regularly with conspecifics as part of affiliative groups. Many of these interactions are cooperative, but many others involve competition for resources. Competitive exchanges are often resolved on the basis of dominance relationships, with higher-ranking individuals receiving priority access to desired goods. Although no single cue can establish permanent dominance relationships, there are some cues that predict dominance fairly reliably across context. In the present study, we focused on two such cues relevant to competing groups: (i the physical sizes of individual members, and (ii their relative number. Using a social competition task, we examined whether, and how, preschool-aged children and adults used differences in physical size and numerical alliances to judge which of two groups should prevail in a competitive exchange for a desired object. These judgments were made when either physical size or number differed between groups (Experiment 1, and when both were available but pitted against each other (Experiments 1 and 2. Our findings revealed that by 3 years of age, humans use multiple perceptible cues in third-party judgments of dominance. Our findings also revealed that 3-year-olds, like adults, weighted these cues flexibly according to the additional factor of overall group size, with the physical sizes of individuals determining dominance in smaller groups (e.g., 2 vs. 4 characters and the relative number of individuals determining dominance in larger groups (e.g., 15 vs. 30 characters. Taken together, our findings suggest that a basic formula for determining dominance in competitive exchanges, which weights physical size of individuals and numerical alliances as a function of overall group size, is available to young children and appears fairly stable through to adulthood.

  1. Children and Adults Use Physical Size and Numerical Alliances in Third-Party Judgments of Dominance.

    Science.gov (United States)

    Lourenco, Stella F; Bonny, Justin W; Schwartz, Bari L

    2015-01-01

    Humans and other social animals interact regularly with conspecifics as part of affiliative groups. Many of these interactions are cooperative, but many others involve competition for resources. Competitive exchanges are often resolved on the basis of dominance relationships, with higher-ranking individuals receiving priority access to desired goods. Although no single cue can establish permanent dominance relationships, there are some cues that predict dominance fairly reliably across context. In the present study, we focused on two such cues relevant to competing groups: (i) the physical sizes of individual members, and (ii) their relative number. Using a social competition task, we examined whether, and how, preschool-aged children and adults used differences in physical size and numerical alliances to judge which of two groups should prevail in a competitive exchange for a desired object. These judgments were made when either physical size or number differed between groups (Experiment 1), and when both were available but pitted against each other (Experiments 1 and 2). Our findings revealed that by 3 years of age, humans use multiple perceptible cues in third-party judgments of dominance. Our findings also revealed that 3-year-olds, like adults, weighted these cues flexibly according to the additional factor of overall group size, with the physical sizes of individuals determining dominance in smaller groups (e.g., 2 vs. 4 characters) and the relative number of individuals determining dominance in larger groups (e.g., 15 vs. 30 characters). Taken together, our findings suggest that a basic formula for determining dominance in competitive exchanges, which weights physical size of individuals and numerical alliances as a function of overall group size, is available to young children and appears fairly stable through to adulthood.

  2. Hemispheric dominance and cell phone use.

    Science.gov (United States)

    Seidman, Michael D; Siegel, Bianca; Shah, Priyanka; Bowyer, Susan M

    2013-05-01

    A thorough understanding of why we hold a cell phone to a particular ear may be of importance when studying the impact of cell phone safety. To determine if there is an obvious association between sidedness of cell phone use and auditory hemispheric dominance (AHD) or language hemispheric dominance (LHD). It is known that 70% to 95% of the population are right-handed, and of these, 96% have left-brain LHD. We have observed that most people use their cell phones in their right ear. An Internet survey was e-mailed to individuals through surveymonkey.com. The survey used a modified Edinburgh Handedness Inventory protocol. Sample questions surveyed which hand was used to write with, whether the right or left ear was used for phone conversations, as well as whether a brain tumor was present. General community. An Internet survey was randomly e-mailed to 5000 individuals selected from an otology online group, patients undergoing Wada testing and functional magnetic resonance imaging, as well as persons on the university listserv, of which 717 surveys were completed. Determination of hemispheric dominance based on preferred ear for cell phone use. A total of 717 surveys were returned. Ninety percent of the respondents were right handed, and 9% were left handed. Sixty-eight percent of the right-handed people used the cell phone in their right ear, 25% in the left ear, and 7% had no preference. Seventy-two of the left-handed respondents used their left ear, 23% used their right ear, and 5% had no preference. Cell phone use averaged 540 minutes per month over the past 9 years. An association exists between hand dominance laterality of cell phone use (73%) and our ability to predict hemispheric dominance. Most right-handed people have left-brain LHD and use their cell phone in their right ear. Similarly, most left-handed people use their cell phone in their left ear. Our study suggests that AHD may differ from LHD owing to the difference in handedness and cell phone ear use

  3. Invasive species in the flora of the Starobilsk grass-meadow steppe (Ukraine

    Directory of Open Access Journals (Sweden)

    Kucher Oksana O.

    2015-06-01

    Full Text Available The results of an investigation of the invasive species in the flora of the Starobilsk grass-meadow steppe are presented. Check-list of alien plant has over 386 species of vascular plants of which 28 species are invasive. We have identified 6 transformer species from the invasive plants. We aggregate data on the entry, distribution history, ecology, occurrence in different plant communities, degree of their naturalization and the habitats where they occur. The leading families of invasive species are: Asteraceae. The basis for this group is presented by origin from the North America and the Mediterranean. With respect to the time of immigration, most of them are kenophytes. By the method of introduction, ksenophytes are dominated; according to the degree of naturalization epoecophytes and agriophytes dominate in this group. With regard to the characteristics of life forms, half of invasive species are terophytes. The vast majority of plants are heliophytes and xeromesophytes. Most species are found in biotopes group I: Cultivated agricultural biotopes; least of all species found in biotopes group F: Biotopes dominated by chamephytes and nanophanerophytes. Only 3 species found in biotopes group F: Biotopes dominated by chamephytesand nanophanerophytes. The maps of distribution of 28 invasive species are provided. Most of the species marked dispersed in more than 30 squares.

  4. Value of Riparian Vegetation Remnants for Leaf-Litter Ants (Hymenoptera: Formicidae) in a Human-Dominated Landscape in Central Veracruz, Mexico.

    Science.gov (United States)

    García-Martínez, Miguel Á; Escobar-Sarria, Federico; López-Barrera, Fabiola; Castaño-Meneses, Gabriela; Valenzuela-González, Jorge E

    2015-12-01

    Riparian remnants are linear strips of vegetation immediately adjacent to rivers that may act as refuges for biodiversity, depending on their habitat quality. In this study, we evaluated the role of riparian remnants in contributing to the diversity of leaf-litter ants by determining the relationship between ant diversity and several riparian habitat characteristics within a human-dominated landscape in Veracruz, Mexico. Sampling was carried out in 2012 during both dry and rainy seasons at 12 transects 100 m in length, where 10 leaf-litter samples were collected along each transect and processed with Berlese-Tullgren funnels and Winkler sacks. A total of 8,684 individuals belonging to 53 species, 22 genera, and seven subfamilies were collected. The observed mean alpha diversity accounted for 34.4% of the total species recorded and beta diversity for 65.6%. Species richness and composition were significantly related to litter-layer depth and soil compaction, which could limit the distribution of ant species depending on their nesting, feeding, and foraging habits. Riparian remnants can contribute toward the conservation of ant assemblages and likely other invertebrate communities that are threatened by anthropogenic pressures. In human-dominated landscapes where remnants of riparian vegetation give refuge to a diverse array of myrmecofauna, the protection of the few remaining and well-preserved riparian sites is essential for the long-term maintenance of biodiversity. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Origin of an Assemblage Massively Dominated by Carnivorans from the Miocene of Spain

    Science.gov (United States)

    Domingo, M. Soledad; Alberdi, M. Teresa; Azanza, Beatriz; Silva, Pablo G.; Morales, Jorge

    2013-01-01

    Carnivoran-dominated fossil sites provide precious insights into the diversity and ecology of species rarely recovered in the fossil record. The lower level assemblage of Batallones-1 fossil site (Late Miocene; Madrid Basin, Spain) has yielded one of the most abundant and diversified carnivoran assemblage ever known from the Cenozoic record of mammals. A comprehensive taphonomic study is carried out here in order to constrain the concentration mode of this remarkable assemblage. Another distinctive feature of Batallones-1 is that the accumulation of carnivoran remains took place in the context of a geomorphological landform (cavity formation through a piping process) practically unknown in the generation of fossil sites. Two characteristics of the assemblage highly restrict the probable causes for the accumulation of the remains: (1) the overwhelming number of carnivorans individuals; and (2) the mortality profiles estimated for the four most abundant taxa do not correspond to the classic mortality types but rather were the consequence of the behavior of the taxa. This evidence together with other taphonomic data supports the hypothesis that carnivoran individuals actively entered the cavity searching for resources (food or water) and were unable to exit. The scarcity of herbivores implies that the shaft was well visible and avoided by these taxa. Fossil bones exhibit a very good preservation state as a consequence of their deposition in the restricted and protective environment of the chamber. Batallones-1 had another assemblage (upper level assemblage) that was dominated by herbivore remains and that potentially corresponded to the final stages of the cavity filling. PMID:23650542

  6. 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.

  7. Eurajoki Olkiluoto study on species of ground beetles and ants 2008

    International Nuclear Information System (INIS)

    Santaharju, J.; Helminen, S.-L.; Yrjoelae, R.

    2009-02-01

    The species of ants and Ground beetles at Olkiluoto in Eurajoki were studied in the summer of 2008 during two trapping periods: in June and August. The research goal was to clarify the species on Olkiluoto island of the earlier mentioned groups, at least at the family level, and to collect samples for further examination by Posiva. The trapping areas were selected at Olkiluoto in Posiva test monitoring sectors, a part of the trapping areas was the same as the earlier study. Species of ants, depending on their particular species, are a very dominating group of insects. The ants are the most important predators, scavengers and soil movers in Finnish forests. It looks as if the biomass of ants may be more than 10% of the biomass of all animals in certain areas of Finnish forests. In Finland there are about 60 species of ants that have been observed. They have been divided into four sub-groups, which are Myrmicinae, Formicinae, Ponerinae and Dolichoderinae. In Finland there are close to 300 species of ground beetles (Carabidae), which are divided into dozens of different families. The species, to a great extent, consist mostly of predatory insects that prey on microbes in field layers, but a part of them are specialized in feeding on flora. Ground beetles are usually divided into three groups according to their choice of habitat: Species that favour open biotopes, species that favour forests, and generalist species that can thrive in a variety of environments. Ground beetles also reflect changes in their living environment, and possibly they can be significant as socalled bio-indicators. Pitfall traps were used as the method of research. The preservative fluid used was ethanol (50%) with dishwashing liquid to remove surface tension. The points were located in various different biotopes in fields, meadows and forests. The data collected was defined as a minimum for the family level of Ground beetles and for ants to the species or species pairs. The species of Ground

  8. Eurajoki Olkiluoto study on species of ground beetles and ants 2008

    Energy Technology Data Exchange (ETDEWEB)

    Santaharju, J.; Helminen, S.-L.; Yrjoelae, R. (Environmental Research Yrjoelae Ltd, Helsinki (Finland))

    2009-02-15

    The species of ants and Ground beetles at Olkiluoto in Eurajoki were studied in the summer of 2008 during two trapping periods: in June and August. The research goal was to clarify the species on Olkiluoto island of the earlier mentioned groups, at least at the family level, and to collect samples for further examination by Posiva. The trapping areas were selected at Olkiluoto in Posiva test monitoring sectors, a part of the trapping areas was the same as the earlier study. Species of ants, depending on their particular species, are a very dominating group of insects. The ants are the most important predators, scavengers and soil movers in Finnish forests. It looks as if the biomass of ants may be more than 10% of the biomass of all animals in certain areas of Finnish forests. In Finland there are about 60 species of ants that have been observed. They have been divided into four sub-groups, which are Myrmicinae, Formicinae, Ponerinae and Dolichoderinae. In Finland there are close to 300 species of ground beetles (Carabidae), which are divided into dozens of different families. The species, to a great extent, consist mostly of predatory insects that prey on microbes in field layers, but a part of them are specialized in feeding on flora. Ground beetles are usually divided into three groups according to their choice of habitat: Species that favour open biotopes, species that favour forests, and generalist species that can thrive in a variety of environments. Ground beetles also reflect changes in their living environment, and possibly they can be significant as socalled bio-indicators. Pitfall traps were used as the method of research. The preservative fluid used was ethanol (50%) with dishwashing liquid to remove surface tension. The points were located in various different biotopes in fields, meadows and forests. The data collected was defined as a minimum for the family level of Ground beetles and for ants to the species or species pairs. The species of Ground

  9. Trait contributions to fish community assembly emerge from trophicinteractions in an individual-based model

    Science.gov (United States)

    Giacomini, Henrique C.; DeAngelis, Donald; Trexler, Joel C.; Petrere, Miguel

    2013-01-01

    Community ecology seeks to understand and predict the characteristics of communities that can develop under different environmental conditions, but most theory has been built on analytical models that are limited in the diversity of species traits that can be considered simultaneously. We address that limitation with an individual-based model to simulate assembly of fish communities characterized by life history and trophic interactions with multiple physiological tradeoffs as constraints on species performance. Simulation experiments were carried out to evaluate the distribution of 6 life history and 4 feeding traits along gradients of resource productivity and prey accessibility. These experiments revealed that traits differ greatly in importance for species sorting along the gradients. Body growth rate emerged as a key factor distinguishing community types and defining patterns of community stability and coexistence, followed by egg size and maximum body size. Dominance by fast-growing, relatively large, and fecund species occurred more frequently in cases where functional responses were saturated (i.e. high productivity and/or prey accessibility). Such dominance was associated with large biomass fluctuations and priority effects, which prevented richness from increasing with productivity and may have limited selection on secondary traits, such as spawning strategies and relative size at maturation. Our results illustrate that the distribution of species traits and the consequences for community dynamics are intimately linked and strictly dependent on how the benefits and costs of these traits are balanced across different conditions.

  10. Species specificity in major urinary proteins by parallel evolution.

    Directory of Open Access Journals (Sweden)

    Darren W Logan

    Full Text Available Species-specific chemosignals, pheromones, regulate social behaviors such as aggression, mating, pup-suckling, territory establishment, and dominance. The identity of these cues remains mostly undetermined and few mammalian pheromones have been identified. Genetically-encoded pheromones are expected to exhibit several different mechanisms for coding 1 diversity, to enable the signaling of multiple behaviors, 2 dynamic regulation, to indicate age and dominance, and 3 species-specificity. Recently, the major urinary proteins (Mups have been shown to function themselves as genetically-encoded pheromones to regulate species-specific behavior. Mups are multiple highly related proteins expressed in combinatorial patterns that differ between individuals, gender, and age; which are sufficient to fulfill the first two criteria. We have now characterized and fully annotated the mouse Mup gene content in detail. This has enabled us to further analyze the extent of Mup coding diversity and determine their potential to encode species-specific cues.Our results show that the mouse Mup gene cluster is composed of two subgroups: an older, more divergent class of genes and pseudogenes, and a second class with high sequence identity formed by recent sequential duplications of a single gene/pseudogene pair. Previous work suggests that truncated Mup pseudogenes may encode a family of functional hexapeptides with the potential for pheromone activity. Sequence comparison, however, reveals that they have limited coding potential. Similar analyses of nine other completed genomes find Mup gene expansions in divergent lineages, including those of rat, horse and grey mouse lemur, occurring independently from a single ancestral Mup present in other placental mammals. Our findings illustrate that increasing genomic complexity of the Mup gene family is not evolutionarily isolated, but is instead a recurring mechanism of generating coding diversity consistent with a species

  11. Diversification of C(4) grasses (Poaceae) does not coincide with their ecological dominance.

    Science.gov (United States)

    Bouchenak-Khelladi, Yanis; Slingsby, Jasper A; Verboom, G Anthony; Bond, William J

    2014-02-01

    The radiation of a lineage and its rise to ecological dominance are distinct phenomena and driven by different processes. For example, paleoecological data has been used to show that the Cretaceous angiosperm radiation did not coincide with their rise to dominance. Using a phylogenetic approach, we here explored the evolution of C4 grasses and evaluated whether the diversification of this group and its rise to ecological dominance in the late Miocene were decoupled. We assembled a matrix including 675 grass species of the PACMAD clade and 2784 characters (ITS and ndhF) to run a molecular dating analysis using three fossils as reference calibrations. We coded species as C3 vs. C4 and reconstructed ancestral states under maximum likelihood. We used the program BiSSE to test whether rates of diversification are correlated with photosynthetic pathway and whether the radiation of C4 lineages preceded or coincided with their rise to ecological dominance from ∼10 Ma. C4 grass lineages first originated around 35 Ma at the time of the Eocene-Oligocene transition. Accelerated diversification of C4 lineages did not coincide with their rise to ecological dominance. C4-dominated grasslands have expanded only since the Late Miocene and Pliocene. The initial diversification of their biotic elements can be tracked back as far as the Eocene-Oligocene transition. We suggest that shifts in taxonomic diversification and ecological dominance were stimulated by different factors, as in the case of the early angiosperms in the Cretaceous.

  12. Ovarian development in a primitively eusocial wasp: social interactions affect behaviorally dominant and subordinate wasps in opposite directions relative to solitary females.

    Science.gov (United States)

    Shukla, Shantanu; Pareek, Vidhi; Gadagkar, Raghavendra

    2014-07-01

    In many primitively eusocial wasp species new nests are founded either by a single female or by a small group of females. In the single foundress nests, the lone female develops her ovaries, lays eggs as well as tends her brood. In multiple foundress nests social interactions, especially dominance-subordinate interactions, result in only one 'dominant' female developing her ovaries and laying eggs. Ovaries of the remaining 'subordinate' cofoundresses remain suppressed and these individuals function as workers and tend the dominant's brood. Using the tropical, primitively eusocial polistine wasp Ropalidia marginata and by comparing wasps held in isolation and those kept as pairs in the laboratory, we demonstrate that social interactions affect ovarian development of dominant and subordinate wasps among the pairs in opposite directions, suppressing the ovaries of the subordinate member of the pair below that of solitary wasps and boosting the ovaries of dominant member of the pair above that of solitary females. In addition to being of physiological interest, such mirror image effects of aggression on the ovaries of the aggressors and their victims, suggest yet another mechanism by which subordinates can enhance their indirect fitness and facilitate the evolution of worker behavior by kin selection. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Atypical hemispheric dominance for attention: functional MRI topography.

    Science.gov (United States)

    Flöel, Agnes; Jansen, Andreas; Deppe, Michael; Kanowski, Martin; Konrad, Carsten; Sommer, Jens; Knecht, Stefan

    2005-09-01

    The right hemisphere is predominantly involved in tasks associated with spatial attention. However, left hemispheric dominance for spatial attention can be found in healthy individuals, and both spatial attention and language can be lateralized to the same hemisphere. Little is known about the underlying regional distribution of neural activation in these 'atypical' individuals. Previously a large number of healthy subjects were screened for hemispheric dominance of visuospatial attention and language, using functional Doppler ultrasonography. From this group, subjects were chosen who were 'atypical' for hemispheric dominance of visuospatial attention and language, and their pattern of brain activation was studied with functional magnetic resonance imaging during a task probing spatial attention. Right-handed subjects with the 'typical' pattern of brain organization served as control subjects. It was found that subjects with an inverted lateralization of language and spatial attention (language right, attention left) recruited left-hemispheric areas in the attention task, homotopic to those recruited by control subjects in the right hemisphere. Subjects with lateralization of both language and attention to the right hemisphere activated an attentional network in the right hemisphere that was comparable to control subjects. The present findings suggest that not the hemispheric side, but the intrahemispheric pattern of activation is the distinct feature for the neural processes underlying language and attention.

  14. Single-cell genomics reveals features of a Colwellia species that was dominant during the Deepwater Horizon oil spill

    Directory of Open Access Journals (Sweden)

    Olivia eMason

    2014-07-01

    Full Text Available During the Deepwater Horizon (DWH oil spill in the Gulf of Mexico a deep-sea hydrocarbon plume developed resulting in a rapid succession of bacteria. Colwellia eventually supplanted Oceanospirillales, which dominated the plume early in the spill. These successional changes may have resulted, in part, from the changing composition and abundance of hydrocarbons over time. Colwellia abundance peaked when gaseous and simple aromatic hydrocarbons increased, yet the metabolic pathway used by Colwellia in hydrocarbon disposition is unknown. Here we used single-cell genomics to gain insights into the genome properties of a Colwellia enriched during the DWH deep-sea plume. A single amplified genome (SAG of a Colwellia cell isolated from a DWH plume, closely related (avg. 98% 16S rRNA gene similarity to other plume Colwellia, was sequenced and annotated. The SAG was similar to the sequenced isolate Colwellia psychrerythraea 34H (84% avg. nucleotide identity. Both had genes for denitrification, chemotaxis and motility, adaptations to cold environments, and a suite of nutrient acquisition genes. The Colwellia SAG may be capable of gaseous and aromatic hydrocarbon degradation, which contrasts with a DWH plume Oceanospirillales SAG genome which encoded non-gaseous n-alkane and cycloalkane degradation. The disparate hydrocarbon degradation pathways are consistent with hydrocarbons that were abundant at different times in the deep-sea plume; first, non-gaseous n-alkanes and cycloalkanes that could be degraded by Oceanospirillales, followed by gaseous, and simple aromatic hydrocarbons that may have been degraded by Colwellia. These insights into the genomic properties of a Colwellia species, which were supported by existing metagenomic sequence data from the plume and DWH contaminated sediments, help further our understanding of the successional changes in the dominant microbial players in the plume over the course of the DWH spill.

  15. Anatomy of Atrioventricular Node Artery and Pattern of Dominancy in Normal Coronary Subject: A Comparison between Individuals with and without Isolated Right Bundle Branch Block.

    Science.gov (United States)

    Kazemisaeid, Ali; Pakbaz, Marziyeh; Yaminisharif, Ahmad; Davoodi, Gholamreza; Lotfi Tokaldany, Masoumeh; Hakki Kazazi, Elham

    2012-11-01

    Isolated right bundle branch block (RBBB) is a common finding in the general population. The atrioventricular node (AVN) artery contributes to the blood supply of the right bundle branch. Our hypothesis was that the anatomy of the AVN artery and the pattern of dominancy differ between subjects with and without RBBB. We retrospectively studied the coronary angiography of 92 patients with RBBB and 184 age- and gender-matched controls without RBBB. All the subjects had angiographically proven normal coronary arteries. The dominant circulation and precise origin of the AVN artery were determined in each subject. Obtained data were compared between the two study groups. There was no significant difference between the two groups in terms of dominancy (p value = 0.200). Origination of the AVN artery from the right circulatory system was more common in both groups, but this pattern was more prevalent in the cases than in the controls (p value = 0.021). There was a great variation of the AVN artery origin. In the total study population, the AVN artery was more commonly separated from a non crux origin than from the crux area. The prevalence of the non-crux origination of the AVN artery was significantly higher in the cases than in the controls (p value AVN artery from the right circulatory system was more common in both groups, the prevalence of the right origin of the AVN artery was significantly higher in the cases than in the controls. We observed that the AVN artery most commonly originated from the dominant artery but not necessarily from the crux. The anatomy of the AVN artery but not the pattern of dominancy is somewhat different in subjects with RBBB compared with normal individuals.

  16. A single European aspen (Populus tremula) tree individual may potentially harbour dozens of Cenococcum geophilum ITS genotypes and hundreds of species of ectomycorrhizal fungi.

    Science.gov (United States)

    Bahram, Mohammad; Põlme, Sergei; Kõljalg, Urmas; Tedersoo, Leho

    2011-02-01

    Ectomycorrhizal fungi (EcMF) form diverse communities and link different host plants into mycorrhizal networks, yet little is known about the magnitude of mycobiont diversity of a single tree individual. This study addresses species richness and spatial structure of EcMF in the root system of a single European aspen (Populus tremula) individual in an old-growth boreal mixed forest ecosystem in Estonia. Combining morphological and molecular identification methods for both plant and fungi, 122 species of EcMF were recovered from 103 root samples of the single tree. Richness estimators predicted the total EcMF richness to range from 182 to 207 species, reflecting the observation of 62.3% singletons and doubletons within the community. Fine-scale genetic diversity in Cenococcum geophilum indicates the presence of 23 internal transcribed spacer genotypes. EcMF community was significantly spatially autocorrelated only at the lineage level up to 3 m distance, but not at the species level. Proximity of other hosts had a significant effect on the spatial distribution of EcMF lineages. This study demonstrates that a single tree may host as many EcMF species and individuals as recovered on multiple hosts in diverse communities over larger areas. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  17. Palmer LTER: Patterns of distribution of five dominant zooplankton species in the epipelagic zone west of the Antarctic Peninsula, 1993 2004

    Science.gov (United States)

    Ross, Robin M.; Quetin, Langdon B.; Martinson, Douglas G.; Iannuzzi, Rich A.; Stammerjohn, Sharon E.; Smith, Raymond C.

    2008-09-01

    Variability in the temporal-spatial distribution and abundance of zooplankton was documented each summer on the Palmer Long-Term Ecological Research (LTER) grid west of the Antarctic Peninsula between Anvers and Adelaide Islands during a 12-yr time series. Oblique tows to 120 m with a 2×2 m fixed-frame net were made at about 50 stations each January/February between 1993 and 2004. The numerically dominant macro- and mesozooplanktonic species >2 mm included three species of euphausiids ( Euphausia superba, Antarctic krill; Thysanoëssa macrura; Euphausia crystallorophias, ice krill), a shelled pteropod ( Limacina helicina), and a salp ( Salpa thompsoni). Life cycles, life spans, and habitat varied among these species. Abundance data from each year were allocated to 100 km by 20 km (alongshore by on/offshore) grid cells centered on cardinal transect lines and stations within the Palmer LTER grid. The long-term mean or climatology and means for each year were used to calculate annual anomalies across the grid. Principal components analysis (PCA) was used to analyze for patterns and trends in the temporal-spatial variability of the five species. Questions included whether there are groups of species with similar patterns, and whether population cycles, species interactions or seasonal sea-ice parameters were correlated with detected patterns. Patterns in the climatology were distinct, and matched those of physical parameters. Common features included higher abundance in the north than in the south, independent of the cross-shelf gradients, and cross-shelf gradients with higher abundance either inshore ( E. crystallorophias) or offshore ( S. thompsoni). Anomalies revealed either cycles in the population, as episodic recruitment in Antarctic krill, or changes in anomaly pattern between the first and second half of the sampling period. The 1998 year, which coincided with a rapid change from a negative to a positive phase in the SOI, emerged as a year with either

  18. Seasonal variations in energy levels and metabolic processes of two dominant Acropora species ( A. spicifera and A. digitifera) at Ningaloo Reef

    Science.gov (United States)

    Hinrichs, S.; Patten, N. L.; Allcock, R. J. N.; Saunders, S. M.; Strickland, D.; Waite, A. M.

    2013-09-01

    Seasonal variations in coral health indices reflecting autotrophic activity (chlorophyll a and zooxanthellae density), metabolic rates (RNA/DNA ratio and protein) and energy storage (ratio of storage: structural lipids or lipid ratios) were examined for two dominant Acropora species [ Acropora digitifera ( AD) and Acropora spicifera ( AS)] at Ningaloo Reef (north-western Australia). Such detailed investigation of metabolic processes is important background, with regard to understanding the vulnerability of corals to environmental change. Health indices in AD and AS were measured before and after spawning in austral autumn and winter 2010, and austral summer 2011 at six stations. Health indices showed seasonal and species-specific differences but negligible spatial differences across a reef section. For AD, autotrophic indices were negatively correlated with lipid ratios and metabolic indices. Metabolic indices were significantly higher in AS than AD. No correlation was observed between RNA/DNA ratios and lipid ratios with any autotrophic indices for AS. Lipid ratios were stable throughout the year for AS while they changed significantly for AD. For both species, indices of metabolic activity were highest during autumn, while autotrophic indices were highest in winter and summer. Results suggest that the impact of the broadcast spawning event on coral health indices at Ningaloo Reef occurred only as a backdrop to massive seasonal changes in coral physiology. The La Niña summer pattern resulted in high autotrophic indices and low metabolic indices and energy stores. Our results imply different metabolic processes in A. digitifera and A. spicifera as well as a strong impact of extreme events on coral physiology.

  19. Differential effects of chronic fluoxetine on the behavior of dominant and subordinate naked mole-rats.

    Science.gov (United States)

    Mongillo, Daniel L; Kosyachkova, Ekaterina A; Nguyen, Tam M; Holmes, Melissa M

    2014-01-01

    Naked mole-rats are eusocial rodents that live in large subterranean colonies with a strict reproductive and social hierarchy. The breeding female (referred to as the queen) and 1 to 3 breeding males are the only reproductive members of the colony. Breeders are socially dominant and all other colony members are non-reproductive subordinates. The effects of manipulating the serotonergic neurotransmitter system on aggression and dominance behaviors are well studied in many species, but not in eusocial rodents like the naked mole-rat. The current study investigated how the serotonergic system influences aggressive/dominant behaviors in this species. To do this, two separate but related experiments were conducted: the effects of fluoxetine hydrochloride (FLX) on status-specific behaviors of subordinates (Experiment 1) and dominant queens (Experiment 2) were evaluated both in-colony and in a social-pairing paradigm. In accordance with our main hypothesis, chronic treatment of FLX attenuated the frequency and duration of aggression in queens, but not subordinates, when paired with an unfamiliar conspecific. Further exploration of pharmacological manipulation on status-specific behaviors of this eusocial species may elucidate the neurobiological mechanisms underlying their unique and rigid social hierarchy. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Species-specific associations between overstory and understory tree species in a semideciduous tropical forest

    Directory of Open Access Journals (Sweden)

    Flaviana Maluf Souza

    2015-03-01

    Full Text Available We investigated the occurrence of associations between overstory and understory tree species in a semideciduous tropical forest. We identified and measured all trees of nine canopy species with diameter at breast height ≥4.8 cm in a 10.24 ha plot and recorded all individuals beneath their canopies ("understory individuals" within the same diameter class. The total density of understory individuals did not significantly differ under different overstory species. One overstory species (Ceiba speciosa showed higher understory species richness compared with five other species. There was a strong positive association between three overstory species (Esenbeckia leiocarpa, Savia dictyocarpa, and C. speciosa and the density of seven understory species (Balfourodendron riedelianum, Chrysophyllum gonocarpum, E. leiocarpa, Holocalyx balansae, Machaerium stipitatum, Rhaminidium elaeocarpum, and S. dictyocarpa. These results probably reflect the outcome of a complex set of interactions including facilitation and competition, and further studies are necessary to better understand the magnitude and type of the effects of individual overstory species on understory species. The occurrence of species-specific associations shown here reinforces the importance of non-random processes in structuring plant communities and suggest that the influence of overstory species on understory species in high-diversity forests may be more significant than previously thought.

  1. Left hemispheric dominance of vestibular processing indicates lateralization of cortical functions in rats.

    Science.gov (United States)

    Best, Christoph; Lange, Elena; Buchholz, Hans-Georg; Schreckenberger, Mathias; Reuss, Stefan; Dieterich, Marianne

    2014-11-01

    Lateralization of cortical functions such as speech dominance, handedness and processing of vestibular information are present not only in humans but also in ontogenetic older species, e.g. rats. In human functional imaging studies, the processing of vestibular information was found to be correlated with the hemispherical dominance as determined by the handedness. It is located mainly within the right hemisphere in right handers and within the left hemisphere in left handers. Since dominance of vestibular processing is unknown in animals, our aim was to study the lateralization of cortical processing in a functional imaging study applying small-animal positron emission tomography (microPET) and galvanic vestibular stimulation in an in vivo rat model. The cortical and subcortical network processing vestibular information could be demonstrated and correlated with data from other animal studies. By calculating a lateralization index as well as flipped region of interest analyses, we found that the vestibular processing in rats follows a strong left hemispheric dominance independent from the "handedness" of the animals. These findings support the idea of an early hemispheric specialization of vestibular cortical functions in ontogenetic older species.

  2. Functional relationship between dominant and non-dominant hand in motor task - hand grip strength endurance

    Directory of Open Access Journals (Sweden)

    Kljajić Dragana

    2012-01-01

    Full Text Available The aim of this study was to determine the functional relationship between dominant and non-dominant hand in the strength endurance motor task - hand grip, in the referent population of healthy and young persons. For the purpose of the research we have implemented the method of isometric dynamometry and standardized hand grip test. The study included 48 participants, 23 of them being of female and 25 of male gender. The analysis of variance (ANOVA was used to determine the difference between the sets of variables in the function of gender and functional dimorphism, while the Bonferroni criterion was applied to determine the differences between pairs of individual variables. The difference between the maximum hand grip of dominant and non-dominant hand in female participants amounted to 9.28%, and in male ones 7.39% in favor of the dominant hand. There is no statistically significant difference between nondominant and dominant hand regarding the force endurance time aspect at 30%, 50% and 80% out of the maximum hand grip level, as well as at the absolute and relative force impulse indicators as an endurance measure. The value of gender dimorphism in relation to the absolute indicators of force momentum at 30%, 50% and 80% out of the maximum hand grip level in female participants is 0.9714, 0.9145, 0.9301, and in male participants 0.9515, 0.8264 and 0.8606. The force momentum indicators value at 30%, 50% and 80% out of the maximum hand grip level in female participants is ImpF30%=21167.58±6923.67 Ns, ImpF50%=10846.94±3800.56 Ns and ImpF80%=5438.46±1993.12 Ns, and in male participants ImpF30%=17734.03±6881.92 Ns, ImpF50%=13903.61±3437.76 Ns and ImpF80%=5117.53±1894.78 Ns. The obtained results can be used as the criteria for further research in special education and rehabilitation, medical and professional rehabilitation.

  3. Spatial Patterns and Interspecific Associations of Three Canopy Species at Different Life Stages in a Subtropical Forest,China

    Institute of Scientific and Technical Information of China (English)

    Lin Li; Shi-Guang Wei; Zhong-Liang Huang; Wan-Hui Ye; Hong-Lin Cao

    2008-01-01

    Spatial patterns of species at different life stages are an important aspect for understanding causal mechanisms that facilitate species co-existence.Using Ripley's univariate L(t) and bivariate L12(t) functions,we analyzed the spatial patterns and interspecific associations of three canopy species at different life history stages in a 20-ha subtropical forest plot in Dinghushan Nature Reserve.Based on diameter at breast height (DBH),four life stages were distinguished.Castanopsis chinensis and Schima superba showed a unimodal DBH distribution.Engelhardtia roxburghiana showed a bimodal curve.L(t) function analysis showed significantly aggregated distributions of all three species at later life stages and random distribution at early life stages at some scales.From the analysis of L12(t) function,the results showed the positive association was a dominant pattern for most species pairs at most scales but the intensity of association decreases with the increase of life stages.Juveniles of the three species had no negative intra- and interspecific associations with the older life stages.Only premature trees were suppressed by overmature trees at some scales.Considering these results,we found three canopy-dominant species that lacked regeneration.There was no direct competition occurring between understorey individuals.Young trees can grow well under conspecific species with two other species.Longevity and lack of regeneration led to a large number of trees stored in mature and overmature stages,therefore,intra-and inter-competition can be strong at later life stages.

  4. Projected shifts in fish species dominance in Wisconsin lakes under climate change.

    Science.gov (United States)

    Hansen, Gretchen J A; Read, Jordan S; Hansen, Jonathan F; Winslow, Luke A

    2017-04-01

    Temperate lakes may contain both coolwater fish species such as walleye (Sander vitreus) and warmwater fish species such as largemouth bass (Micropterus salmoides). Recent declining walleye and increasing largemouth bass populations have raised questions regarding the future trajectories and management actions for these species. We developed a thermodynamic model of water temperatures driven by downscaled climate data and lake-specific characteristics to estimate daily water temperature profiles for 2148 lakes in Wisconsin, US, under contemporary (1989-2014) and future (2040-2064 and 2065-2089) conditions. We correlated contemporary walleye recruitment and largemouth bass relative abundance to modeled water temperature, lake morphometry, and lake productivity, and projected lake-specific changes in each species under future climate conditions. Walleye recruitment success was negatively related and largemouth bass abundance was positively related to water temperature degree days. Both species exhibited a threshold response at the same degree day value, albeit in opposite directions. Degree days were predicted to increase in the future, although the magnitude of increase varied among lakes, time periods, and global circulation models (GCMs). Under future conditions, we predicted a loss of walleye recruitment in 33-75% of lakes where recruitment is currently supported and a 27-60% increase in the number of lakes suitable for high largemouth bass abundance. The percentage of lakes capable of supporting abundant largemouth bass but failed walleye recruitment was predicted to increase from 58% in contemporary conditions to 86% by mid-century and to 91% of lakes by late century, based on median projections across GCMs. Conversely, the percentage of lakes with successful walleye recruitment and low largemouth bass abundance was predicted to decline from 9% of lakes in contemporary conditions to only 1% of lakes in both future periods. Importantly, we identify up to 85

  5. Seasonal Changes in Bird Species and Feeding Guilds along Elevational Gradients of the Central Himalayas, Nepal

    Science.gov (United States)

    Katuwal, Hem Bahadur; Basnet, Khadga; Khanal, Bhaiya; Devkota, Shiva; Rai, Sanjeev Kumar; Gajurel, Jyoti Prasad; Scheidegger, Christoph; Nobis, Michael P.

    2016-01-01

    The Himalayas are a global hotspot for bird diversity with a large number of threatened species, but little is known about seasonal changes in bird communities along elevational gradients in this region. We studied the seasonality of bird diversity in six valleys of the Central Himalayas, Nepal. Using 318 plots with a 50 m radius, located from 2200 to 3800 m a.s.l., and repeated sampling during different seasons (mainly pre-monsoon, monsoon, and post-monsoon), we analyzed 3642 occurrences of 178 species. Birds classified in the literature as resident were more species-rich than migratory birds (140 vs. 38 species). In all six valleys and within the studied elevation range, species richness of all birds showed a peak at mid-elevation levels of 2600 or 3000 m a.s.l. Similar patterns were found for the most species-rich feeding guilds of insectivores (96 species) and omnivores (24 species), whereas the species richness of herbivores (37 species including frugivores) increased towards higher elevations. Among these feeding guilds, only species richness of insectivores showed pronounced seasonal changes with higher species numbers during post-monsoon season. Similarly, individual bird species showed distinct spatio-temporal distribution patterns, with transitions from species dominated by elevational differences to those characterized by strong seasonal changes. In an era of climate change, the results demonstrate that individual bird species as well as feeding guilds might greatly differ in their responses to climate warming and changes in the seasonality of the precipitation regime, two aspects of climate change which should not be analyzed independently. PMID:27367903

  6. Exploration of bacterial species associated with the salivary microbiome of individuals with a low susceptibility to dental caries.

    Science.gov (United States)

    Yasunaga, Haruna; Takeshita, Toru; Shibata, Yukie; Furuta, Michiko; Shimazaki, Yoshihiro; Akifusa, Sumio; Ninomiya, Toshiharu; Kiyohara, Yutaka; Takahashi, Ichiro; Yamashita, Yoshihisa

    2017-11-01

    Dental caries is caused by acidogenic plaque microbiota formed on saliva-bathed tooth surfaces, in which multiple organisms act collectively to initiate and expand a cavity. We explored bacterial species associated with the salivary microbiome of individuals with low susceptibility to dental caries. The bacterial composition of saliva from 19 young adults was analyzed using barcoded pyrosequencing of the 16S rRNA gene; we compared 10 caries-experienced (CE) and nine caries-free (CF) individuals. A quantitative PCR assay of saliva from 139 orally healthy adults aged 40-59 years was carried out to confirm the result obtained by pyrosequencing analysis. The microbiomes of CF individuals showed more diverse communities with a significantly greater proportion of the genus Porphyromonas. Among operational taxonomic units (OTUs) corresponding to the genus Porphyromonas, the OTU corresponding to P. pasteri was the most predominant and its relative abundance in CF individuals was significantly greater than in CE individuals (P oral microbiome against dental caries.

  7. Radiation-induced dominant skeletal mutations in mice

    International Nuclear Information System (INIS)

    Selby, P.B.

    1979-01-01

    Skeletons were chosen for the attempt to determine the overall damage by radiation to one body system largely bacause they can be prepared readily for detailed study. Dominant mutations were of special interest because they are the type of mutations that would account for almost all damage induced in the early generations. The male offsprings derived from spermatogonial irradiation were used in the mutation-rate experiment, and the mutation frequency of 1.4% per gamete was found. The general dominant skeletal mutations are 1) the fusions of bones or other changes in individual bones, 2) the gross changes in bone shapes, usually caused by incomplete or too extensive bone growth, or 3) the shifts in the relative positions of bones. The recessive lethality in the period between implantation and birth can be recognized by the expected high death rate of implants in approximately 1/4 of the crosses that are between heterozygotes for a given mutation. The recessive lethal mutations may account for an important fraction of human genetic disorders owing to their dominant deleterious effects which represent only a small fraction, but because of their easy detection, they have been studied more than other dominants. At least 45, or 27%, of 164 dominant visibles in mice, ignoring those concerned with enzyme polymorphisms and immunological traits, appear to be recessive lethals. (Yamashita, S.)

  8. Linking Keystone Species and Functional Groups: A New Operational Definition of the Keystone Species Concept

    Directory of Open Access Journals (Sweden)

    Robert D. Davic

    2003-07-01

    Full Text Available The concept of the "keystone species" is redefined to allow for the a priori prediction of these species within ecosystems. A keystone species is held to be a strongly interacting species whose top-down effect on species diversity and competition is large relative to its biomass dominance within a functional group. This operational definition links the community importance of keystone species to a specific ecosystem process, e.g., the regulation of species diversity, within functional groups at lower trophic levels that are structured by competition for a limited resource. The a priori prediction of keystone species has applied value for the conservation of natural areas.

  9. Social dominance orientation moderates the effectiveness of mindset messages.

    Science.gov (United States)

    Hoyt, Crystal L; B Forsyth, Rachel; Burnette, Jeni L

    2018-04-01

    In this work, we examine whether differences in social dominance orientation (SDO) moderate the effectiveness of mindsets of intelligence messages. We suggest that SDO is a foundational ideological belief system, on which individuals vary, that maintains the desire to endorse fixed beliefs about the nature of human intelligence. Thus, attempts to change individuals' mindsets should be met with resistance from those who strongly endorse the social dominance ideology - individuals high on SDO. In contrast, individuals low on SDO are less likely to use mindsets of intelligence to justify an ideological belief system, and thus, mindset manipulations should be effective for them. We test these predictions across three experimental studies (N Study1  = 271, N Study2  = 207, N Study3  = 313). Across the studies, we find that individuals who are high, relative to low, on SDO have more fixed beliefs about the nature of intelligence and show smaller effects of manipulations of mindsets. However, when comparing to a control condition, there was no evidence that high-SDO participants resisted the growth message that contradicts their ideology more than the fixed one that supports it; additionally, low-SDO participants showed heightened responsiveness to a fixed message. We discuss implications for theoretical advances in our understanding of mindsets. © 2018 The British Psychological Society.

  10. Species composition and structure of a photophilic algal community dominated by Halopteris scoparia (L. Sauvageau from the North-Western Mediterranean

    Directory of Open Access Journals (Sweden)

    Ballesteros, Enric

    1993-12-01

    Full Text Available A photophilic agal community dominated by Halopteris scoparia and other brown algae is described from sheltered environments from the North-Western Mediterranean rocky bottoms. This community is included in the Padino-Cladostephetum hirsutae previously described by FELDMANN(1937 for the same geographical area. This plant association is characterized by the lack of an upper erect stratum of Fucales and by the low degree of presence of thermophilic species which typify other similar communities described from other Mediterranean areas. Algal biomass ranges from 1100 to 2500 g dw m-2 and coverage percentage ranges from 250 to 450 %. The great miniaturization and the extraordinary diversity and species richness of Mediterranean photophilic algal communities is assessed. Although there is not a clear seasonal change in biomass of the dominant species in the community, two structural stages can be discerned along an annual cycle: a developed community (summer and a diversified community (winter. Finally, the community structure and the environmental factors that impinge upon it are compared with those found in other Mediterranean phytobenthic communities.

    Se describe una comunidad de algas fotófilas mediterráneas de modo calmado dominada por Hatopteris scoparia y otros feófitos de porte mediano, la cual se adscribe a la asociación Padino-Clodostephetum hirsutae J. Feldmann 1937. Dicha asociación se caracteriza por la ausencia de un estrato elevado de Fucales y el escaso grado de presencia de especies termófilas propia de comunidades similares descritas de otras zonas del Mediterráneo. La biomasa algal oscila entre 1100 y 2500 g ps m-2 mientras que el porcentaje de recubrimiento varía entre el 250 y el 450%. Se pone de manifiesto la gran miniaturización de las comunidades de algas fotólitas mediterráneas y su extraordinaria diversidad y riqueza especificas. Pese a no existir un claro

  11. Seasonal Trends and Inter-Individual Heterogeneity: A multi-species record of Mg, Sr, Ba, & Mn in Planktic Foraminifera from the Modern Cariaco Basin

    Science.gov (United States)

    Davis, C. V.; Thunell, R.; Astor, Y. M.

    2017-12-01

    The trace element to calcium ratios (TE/Ca) of planktic foraminifera shells are a valuable tool for paleoceanographic reconstructions, and represent a combination of environmental, ecological and biological signals. We present here a three-year record (2010-2013) of TE/Ca (Mg, Sr, Ba, Mn) from four species of foraminifera (Orbulina universa, Globigerina ruber, Globigerinella siphonifera, and Globorotalia menardii) collected by plankton tow in the modern Cariaco basin. Each tow is paired with in situ measurements of water column properties, allowing a direct comparison between shell geochemistry and calcification environment. A combination of Laser Ablation and solution ICP-MS analyses are used to document seasonality, primarily due to the alternating influence of wind-driven coastal upwelling and riverine inputs, in shell TE/Ca. Individual shell data further allows for the quantification of trace element heterogeneity among individual shells within single tows. All TE/Ca ratios vary temporally and show inter-individual variability within single tows. The spread in TE/Ca differs between element and species, with Mg/Ca ratios being the most variable. Despite this, Mg/Ca still tracks temperature changes in G. ruber, O. universa, and G. menardii, with G. ruber most closely reproducing sea surface temperature. Some species show chamber-to-chamber differences in trace element ratios, with G. ruber Mg/Ca and Ba/Ca decreasing in younger chambers (but not other elements) and Mg/Ca, Mn/Ca and Ba/Ca decreasing in younger chambers in G. siphonifera. We find the original Mn/Ca to be variable both temporally and between species, with G. menardii in some samples having extremely high ratios (100 μmol/mol). Assessing seasonal trends and environmental drivers of TE/Ca variability and quantifying the extent of inter-individual heterogeneity in these species will inform the use of their shells as geochemical proxies.

  12. Influence of species, size and relative abundance on the outcomes of competitive interactions between brook trout and juvenile coho salmon

    Science.gov (United States)

    Thornton, Emily J; Duda, Jeff; Quinn, Thomas P.

    2016-01-01

    Resource competition between animals is influenced by a number of factors including the species, size and relative abundance of competing individuals. Stream-dwelling animals often experience variably available food resources, and some employ territorial behaviors to increase their access to food. We investigated the factors that affect dominance between resident, non-native brook trout and recolonizing juvenile coho salmon in the Elwha River, WA, USA, to see if brook trout are likely to disrupt coho salmon recolonization via interference competition. During dyadic laboratory feeding trials, we hypothesized that fish size, not species, would determine which individuals consumed the most food items, and that species would have no effect. We found that species, not size, played a significant role in dominance; coho salmon won 95% of trials, even when only 52% the length of their brook trout competitors. As the pairs of competing fish spent more time together during a trial sequence, coho salmon began to consume more food, and brook trout began to lose more, suggesting that the results of early trials influenced fish performance later. In group trials, we hypothesized that group composition and species would not influence fish foraging success. In single species groups, coho salmon consumed more than brook trout, but the ranges overlapped. Brook trout consumption remained constant through all treatments, but coho salmon consumed more food in treatments with fewer coho salmon, suggesting that coho salmon experienced more intra- than inter-specific competition and that brook trout do not pose a substantial challenge. Based on our results, we think it is unlikely that competition from brook trout will disrupt Elwha River recolonization by coho salmon.

  13. Leadership behavior in relation to dominance and reproductive status in gray wolves, Canis lupus

    Science.gov (United States)

    Peterson, R.O.; Jacobs, A.K.; Drummer, T.D.; Mech, L.D.; Smith, D.W.

    2002-01-01

    We analyzed the leadership behavior of breeding and nonbreeding gray wolves (Canis lupus) in three packs during winter in 1997-1999. Scent-marking, frontal leadership (time and frequency in the lead while traveling), initiation of activity, and nonfrontal leadership were recorded during 499 h of ground-based observations in Yellowstone National Park. All observed scent-marking (N = 158) was done by breeding wolves, primarily dominant individuals. Dominant breeding pairs provided most leadership, consistent with a trend in social mammals for leadership to correlate with dominance. Dominant breeding wolves led traveling packs during 64% of recorded behavior bouts (N = 591) and 71% of observed travel time (N = 64 h). During travel, breeding males and females led packs approximately equally, which probably reflects high parental investment by both breeding male and female wolves. Newly initiated behaviors (N = 104) were prompted almost 3 times more often by dominant breeders (70%) than by nonbreeders (25%). Dominant breeding females initiated pack activities almost 4 times more often than subordinate breeding females (30 vs. 8 times). Although one subordinate breeding female led more often than individual nonbreeders in one pack in one season, more commonly this was not the case. In 12 cases breeding wolves exhibited nonfrontal leadership. Among subordinate wolves, leadership behavior was observed in subordinate breeding females and other individuals just prior to their dispersal from natal packs. Subordinate wolves were more often found leading packs that were large and contained many subordinate adults.

  14. Checklist of invasive alien species in CSIR-NBRI Botanic Garden, Lucknow, India

    Directory of Open Access Journals (Sweden)

    Shilpi Singh

    2015-08-01

    Full Text Available The invasive alien species of CSIR-NBRI Botanic Garden are enumerated and their impact on the surrounding ecosystem are discussed. This study deals with the information on habit, nativity and family of plant species occurring in the area of study. A total of 103 invasive alien species under 86 genera and 36 families were recorded. Among these, the eudicotyledons represent 85 species, 69 genera and 32 families; monocotyledons represent 18 species, 17 genera and 4 families. In terms of nativity, species from Tropical America are the most dominant group with 34 species. In addition, based on life forms, herbs are dominant (88 species, followed by shrubs (8 species, climbers (4 species and trees (3 species.

  15. Food resource use by two territorial damselfish (Pomacentridae: Stegastes) on South-Western Atlantic algal-dominated reefs

    Science.gov (United States)

    Feitosa, João Lucas L.; Concentino, Adilma M.; Teixeira, Simone F.; Ferreira, Beatrice P.

    2012-05-01

    Damselfishes are a highly abundant group of reef fishes that are considered keystone species for structuring benthic communities on coral-dominated reefs. To assess how food is utilized by the damselfish species Stegastes fuscus and Stegastes variabilis living on algae-dominated coastal reefs, we evaluated the compositions of algal communities inside their territories and investigated their diets by analyzing their stomach contents. Jointed-calcareous algae were the most abundant morphological group inside the territories of both damselfish species (> 80%), and the biomass of these algae showed a positive linear relationship to all the other non-calcareous algae when grouped together (R² = 0.674; p 70%), but they also fed on invertebrates and detritus as accessory items (~ 15%). Algal material composed a consistent proportion of the items ingested by adults and juveniles of both damselfish species with diatoms being the most frequent item, followed by filamentous algae. A positive food selection for all macroalgae morphological groups was observed, except for jointed-calcareous algae (Ivlev's index). The most preferred macroalgae types were filamentous, with values close to + 1 for both damselfish species. Pianka's food overlap index was extremely high regardless of the damselfish species or their life phase and ANOSIM analyses also confirmed that there were essentially no differences between their diets. The present work is the first indication that damselfish may maintain territories dominated by highly unpalatable calcareous macroalgae that have herbivore-deterrent life strategies, although the complex branching structures of these macroalgae create suitable microhabitats for the growth of epiphytic species consumed by the damselfish.

  16. Changes of Species Richness in Heathland Communities over 15 Years following Disturbances

    Directory of Open Access Journals (Sweden)

    L. Calvo

    2012-01-01

    Full Text Available The aim of this study was to define the species richness patterns over a period of 15 years during the vegetation recovery process after disturbances (burning, cutting and ploughing in heathlands. Three communities were selected: two dominated by Erica australis and one dominated by Calluna vulgaris. The alpha and gamma diversity patterns were site specific and influenced by the ecological traits of dominant shrub species. The shrubland dominated by Erica australis, typical resprouters with a fast regeneration, showed the highest values of alpha and gamma diversity during the first 7 years of regeneration. The heathland dominated by Calluna vulgaris, an obligate seeder, had a contrasting pattern of alpha and gamma diversity, as the highest values appeared from year 7 until year 14. Thus, the speed of regeneration of the dominant shrub species could be the main factor affecting structural parameters in these communities. Species richness patterns did not vary in relation to the different types of perturbation. Cutting and burning would be the most suitable forestry management strategies to conserve Erica australis heathlands, but burning is more appropriate in Calluna vulgaris ones because cutting modified this community.

  17. Sex-linked dominant

    Science.gov (United States)

    Inheritance - sex-linked dominant; Genetics - sex-linked dominant; X-linked dominant; Y-linked dominant ... can be either an autosomal chromosome or a sex chromosome. It also depends on whether the trait ...

  18. Metabolic engineering of the Chl d-dominated cyanobacterium Acaryochloris marina: production of a novel Chl species by the introduction of the chlorophyllide a oxygenase gene.

    Science.gov (United States)

    Tsuchiya, Tohru; Mizoguchi, Tadashi; Akimoto, Seiji; Tomo, Tatsuya; Tamiaki, Hitoshi; Mimuro, Mamoru

    2012-03-01

    In oxygenic photosynthetic organisms, the properties of photosynthetic reaction systems primarily depend on the Chl species used. Acquisition of new Chl species with unique optical properties may have enabled photosynthetic organisms to adapt to various light environments. The artificial production of a new Chl species in an existing photosynthetic organism by metabolic engineering provides a model system to investigate how an organism responds to a newly acquired pigment. In the current study, we established a transformation system for a Chl d-dominated cyanobacterium, Acaryochloris marina, for the first time. The expression vector (constructed from a broad-host-range plasmid) was introduced into A. marina by conjugal gene transfer. The introduction of a gene for chlorophyllide a oxygenase, which is responsible for Chl b biosynthesis, into A. marina resulted in a transformant that synthesized a novel Chl species instead of Chl b. The content of the novel Chl in the transformant was approximately 10% of the total Chl, but the level of Chl a, another Chl in A. marina, did not change. The chemical structure of the novel Chl was determined to be [7-formyl]-Chl d(P) by mass spectrometry and nuclear magnetic resonance spectroscopy. [7-Formyl]-Chl d(P) is hypothesized to be produced by the combined action of chlorophyllide a oxygenase and enzyme(s) involved in Chl d biosynthesis. These results demonstrate the flexibility of the Chl biosynthetic pathway for the production of novel Chl species, indicating that a new organism with a novel Chl might be discovered in the future.

  19. The karyotype and 5S rRNA genes from Spanish individuals of the bat species Rhinolophus hipposideros (Rhinolophidae; Chiroptera).

    Science.gov (United States)

    Puerma, Eva; Acosta, Manuel J; Barragán, Maria José L; Martínez, Sergio; Marchal, Juan Alberto; Bullejos, Mónica; Sánchez, Antonio

    2008-11-01

    The karyotype of individuals of the species Rhinolophus hipposideros from Spain present a chromosome number of 2n = 54 (NFa = 62). The described karyotype for these specimens is very similar to another previously described in individual from Bulgaria. However, the presence of one additional pair of autosomal acrocentric chromosomes in the Bulgarian karyotype and the differences in X chromosome morphology indicated that we have described a new karyotype variant in this species. In addition, we have analyzed several clones of 1.4 and 1 kb of a PstI repeated DNA sequence from the genome of R. hipposideros. The repeated sequence included a region with high identity with the 5S rDNA genes and flanking regions, with no homology with GenBank sequences. Search for polymerase III regulatory elements demonstrated the presence of type I promoter elements (A-box, Intermediate Element and C-box) in the 5S rDNA region. In addition, upstream regulatory elements, as a D-box and Sp1 binding sequences, were present in flanking regions. All data indicated that the cloned repeated sequences are the functional rDNA genes from this species. Finally, FISH demonstrated the presence of rDNA in nine chromosome pairs, which is surprising as most mammals have only one carrier chromosome pair.

  20. Environmental consequences of the desire to dominate and be superior.

    Science.gov (United States)

    Milfont, Taciano L; Richter, Isabel; Sibley, Chris G; Wilson, Marc S; Fischer, Ronald

    2013-09-01

    A belief in human dominance over nature lies at the heart of current environmental problems. In this article, we extend the theoretical scope of social dominance theory by arguing that social dominance orientation (SDO) is an important variable in understanding person-environment relations. We argue that individuals high in SDO are more willing to exploit the environment in unsustainable ways because SDO promotes human hierarchical dominance over nature. Four studies provide support for this perspective. High SDO was associated with lower levels of environmental concern in a nationally representative New Zealand sample (Study 1) and in country-level data across 27 nations (Study 2). SDO was also positively related to utilization attitudes toward nature (Study 3) and mediated the gender difference in beliefs about anthropogenic climate change (Study 4), and both occurred independently of right-wing authoritarianism. Implications for the human-dominated view of nature subscribed to by those high in SDO are discussed.

  1. Modulating effects in learned helplessness of dyadic dominance-submission relations.

    Science.gov (United States)

    Díaz-Berciano, Cristina; de Vicente, Francisco; Fontecha, Elisa

    2008-01-01

    In this experiment, learned helplessness was studied from an ethological perspective by examining individual differences in social dominance and its influence on the effects of helplessness. Ninety animals were used, 30 randomly selected and 60 selected because of their clear dominance or submission. Each condition (dominant, submissive, and random) was distributed in three subgroups corresponding to the triadic design. The test consisted of an escape/avoidance task. The results showed that the animals in the uncontrollable condition performed worse than those in the controllable and no treatment conditions. Social submission and dominance reduced vulnerability of the subjects against learned helplessness. Submission had a facilitating effect on subsequent learning, independently of whether pretreatment was controllability or uncontrollability. Learned mastery was observed in the submissive condition, because submission benefited the subjects in the controllable condition in comparison with the untreated subjects, and dominance impaired the subjects in the controllable condition. Copyright 2007 Wiley-Liss, Inc.

  2. Species identity and depth predict bleaching severity in reef-building corals: shall the deep inherit the reef?

    Science.gov (United States)

    Muir, Paul R; Marshall, Paul A; Abdulla, Ameer; Aguirre, J David

    2017-10-11

    Mass bleaching associated with unusually high sea temperatures represents one of the greatest threats to corals and coral reef ecosystems. Deeper reef areas are hypothesized as potential refugia, but the susceptibility of Scleractinian species over depth has not been quantified. During the most severe bleaching event on record, we found up to 83% of coral cover severely affected on Maldivian reefs at a depth of 3-5 m, but significantly reduced effects at 24-30 m. Analysis of 153 species' responses showed depth, shading and species identity had strong, significant effects on susceptibility. Overall, 73.3% of the shallow-reef assemblage had individuals at a depth of 24-30 m with reduced effects, potentially mitigating local extinction and providing a source of recruits for population recovery. Although susceptibility was phylogenetically constrained, species-level effects caused most lineages to contain some partially resistant species. Many genera showed wide variation between species, including Acropora, previously considered highly susceptible. Extinction risk estimates showed species and lineages of concern and those likely to dominate following repeated events. Our results show that deeper reef areas provide refuge for a large proportion of Scleractinian species during severe bleaching events and that the deepest occurring individuals of each population have the greatest potential to survive and drive reef recovery. © 2017 The Author(s).

  3. Mite species (Acari: Mesostigmata new and rare to Polish fauna, inhabiting the soil of broadleaved forests dominated by small-leaved lime (Tilia cordata Mill. in Kwidzyn Forest District (N Poland

    Directory of Open Access Journals (Sweden)

    FALEŃCZYK-KOZIRÓG KATARZYNA

    2014-06-01

    Full Text Available During a two-year study on mites of the order Mesostigmata in broadleaved forest stands dominated by small-leaved lime (Tilia cordata Mill., 117 mite species were identified. Among them, 3 had been so far rarely recorded in Poland (Haemogamasus nidi, Stylochirus rovenensis and Eugamasus crassitarsis and 2 were classified as new to the Polish fauna (Veigaia sibirica and Digamasellus perpusillus.

  4. Individual Recognition in Ant Queens

    DEFF Research Database (Denmark)

    D'Ettorre, Patrizia; Heinze, Jürgen

    2005-01-01

    Personal relationships are the cornerstone of vertebrate societies, but insect societies are either too large for individual recognition, or their members were assumed to lack the necessary cognitive abilities 1 and 2 . This paradigm has been challenged by the recent discovery that paper wasps...... recognize each other's unique facial color patterns [3] . Individual recognition is advantageous when dominance hierarchies control the partitioning of work and reproduction 2 and 4 . Here, we show that unrelated founding queens of the ant Pachycondyla villosa use chemical cues to recognize each other...... individually. Aggression was significantly lower in pairs of queens that had previously interacted than in pairs with similar social history but no experience with one another. Moreover, subordinates discriminated familiar and unfamiliar dominants in choice experiments in which physical contact, but not odor...

  5. A single dominant Ganoderma species is responsible for root rot of ...

    African Journals Online (AJOL)

    Ganoderma root rot is the most serious disease affecting commercially planted Acacia mangium in plantations in Indonesia. Numerous Ganoderma spp. have been recorded from diseased trees of this species and to a lesser extent Eucalyptus, causing confusion regarding the primary cause of the disease. In this study, a ...

  6. The relation between dominance and exploratory behavior is context-dependent in wild great tits

    NARCIS (Netherlands)

    Dingemanse, N.J.; De Goede, P.

    2004-01-01

    Individual differences in personality affect behavior in novel or challenging situations. Personality traits may be subject to selection because they affect the ability to dominate others. We investigated whether dominance rank at feeding tables in winter correlated with a heritable personality

  7. Breeding bird density does not drive vocal individuality

    Directory of Open Access Journals (Sweden)

    Daniel T. BLUMSTEIN, Douglas R. MCCLAIN, Carrie DE JESUS, Gustavo ALARCÓN-NIETO

    2012-10-01

    Full Text Available Many species produce individually specific vocalizations and sociality is a hypothesized driver of such individuality. Previous studies of how social variation influenced individuality focused on colonial or non-colonial avian species, and how social group size influenced individuality in sciurid rodents. Since sociality is an important driver of individuality, we expected that bird species that defend nesting territories in higher density neighborhoods should have more individually-distinctive calls than those that defend nesting territories in lower-density neighborhoods. We used Beecher’s information statistic to quantify individuality, and we examined the relationship between bird density (calculated with point-counts and vocal individuality on seven species of passerines. We found non-significant relationships between breeding bird density and vocal individuality whether regressions were fitted on species values, or on phylogenetically-independent contrast values. From these results, we infer that while individuality may be explained by social factors, breeding bird density is unlikely to be generally important in driving the evolution of individually-specific vocalizations [Current Zoology 58 (5: 765–772, 2012].

  8. Selenium:Mercury Molar Ratios in Freshwater Fish from Tennessee: Individual, Species, and Geographical Variations have Implications for Management

    Science.gov (United States)

    Burger, Joanna; Gochfeld, Michael; Jeitner, C.; Donio, M.; Pittfield, T.

    2014-01-01

    Vertebrates, including humans, can experience adverse effects from mercury consumed in fish. Humans often prefer large predatory fish that bioaccumulate high mercury levels. Recent attention has focused on the role of selenium countering mercury toxicity, but there is little research on the selenium:mercury molar ratios in freshwater fish. We examine selenium:mercury molar ratios in freshwater fish from Tennessee at Poplar Creek which receives ongoing inputs of mercury from the Department of Energy’s Oak Ridge Y-12 facility. Our objective was to determine variation of the ratios within species that might affect the protectiveness of selenium against mercury toxicity. Within species, the ratio was correlated significantly and positively with fish length only for two species. There was great individual variation in the selenium:mercury molar ratio within each species, except striped bass. The lack of a clear relationship between the selenium:mercury molar ratio and fish length, and the intraspecific variation, suggests that it would be difficult to use the molar ratio in predicting either the risk from mercury toxicity or in devising consumption advisories. PMID:22456727

  9. Comparison of biofilm ecology supporting growth of individual Naegleria species in a drinking water distribution system.

    Science.gov (United States)

    Puzon, Geoffrey J; Wylie, Jason T; Walsh, Tom; Braun, Kalan; Morgan, Matthew J

    2017-04-01

    Free-living amoebae (FLA) are common components of microbial communities in drinking water distribution systems (DWDS). FLA are of clinical importance both as pathogens and as reservoirs for bacterial pathogens, so identifying the conditions promoting amoebae colonisation of DWDSs is an important public health concern for water utilities. We used high-throughput amplicon sequencing to compare eukaryotic and bacterial communities associated with DWDS biofilms supporting distinct FLA species (Naegleria fowleri, N. lovaniensis or Vermamoeba sp.) at sites with similar physical/chemical conditions. Eukaryote and bacterial communities were characteristics of different FLA species presence, and biofilms supporting Naegleria growth had higher bacterial richness and higher abundance of Proteobacteria, Bacteroidetes (bacteria), Nematoda and Rotifera (eukaryota). The eukaryotic community in the biofilms had the greatest difference in relation to the presence of N. fowleri, while the bacterial community identified individual bacterial families associated with the presence of different Naegleria species. Our results demonstrate that ecogenomics data provide a powerful tool for studying the microbial and meiobiotal content of biofilms, and, in these samples can effectively discriminate biofilm communities supporting pathogenic N. fowleri. The identification of microbial species associated with N. fowleri could further be used in the management and control of N. fowleri in DWDS. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. The dominance behavioral system and manic temperament: motivation for dominance, self-perceptions of power, and socially dominant behaviors.

    Science.gov (United States)

    Johnson, Sheri L; Carver, Charles S

    2012-12-15

    The dominance behavioral system has been conceptualized as a biologically based system comprising motivation to achieve social power and self-perceptions of power. Biological, behavioral, and social correlates of dominance motivation and self-perceived power have been related to a range of psychopathological tendencies. Preliminary evidence suggests that mania and risk for mania (manic temperament) relate to the dominance system. Four studies examine whether manic temperament, measured with the Hypomanic Personality Scale (HPS), is related to elevations in dominance motivation, self-perceptions of power, and engagement in socially dominant behavior across multiple measures. In Study 1, the HPS correlated with measures of dominance motivation and the pursuit of extrinsically-oriented ambitions for fame and wealth among 454 undergraduates. In Study 2, the HPS correlated with perceptions of power and extrinsically-oriented lifetime ambitions among 780 undergraduates. In Study 3, the HPS was related to trait-like tendencies to experience hubristic (dominance-related) pride, as well as dominance motivation and pursuit of extrinsically-oriented ambitions. In Study 4, we developed the Socially Dominant Behavior Scale to capture behaviors reflecting high power. The scale correlated highly with the HPS among 514 undergraduates. The studies rely on self-ratings of manic temperament and dominance constructs, and findings have not yet been generalized to a clinical sample. Taken together, results support the hypothesis that manic temperament is related to a focus on achieving social dominance, ambitions related to achieving social recognition, perceptions of having achieved power, tendencies to experience dominance-related pride, and engagement in social behaviors consistent with this elevated sense of power. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Modelling Dominance Hierarchies Under Winner and Loser Effects.

    Science.gov (United States)

    Kura, Klodeta; Broom, Mark; Kandler, Anne

    2015-06-01

    Animals that live in groups commonly form themselves into dominance hierarchies which are used to allocate important resources such as access to mating opportunities and food. In this paper, we develop a model of dominance hierarchy formation based upon the concept of winner and loser effects using a simulation-based model and consider the linearity of our hierarchy using existing and new statistical measures. Two models are analysed: when each individual in a group does not know the real ability of their opponents to win a fight and when they can estimate their opponents' ability every time they fight. This estimation may be accurate or fall within an error bound. For both models, we investigate if we can achieve hierarchy linearity, and if so, when it is established. We are particularly interested in the question of how many fights are necessary to establish a dominance hierarchy.

  12. Workers dominate male production in the neotropical bumblebee Bombus wilmattae (Hymenoptera: Apidae

    Directory of Open Access Journals (Sweden)

    Vandame Rémy

    2011-06-01

    Full Text Available Abstract Background Cooperation and conflict in social insects are closely linked to the genetic structure of the colony. Kin selection theory predicts conflict over the production of males between the workers and the queen and between the workers themselves, depending on intra-colonial relatedness but also on other factors like colony efficiency, sex ratios, cost of worker reproduction and worker dominance behaviour. In most bumblebee (Bombus species the queen wins this conflict and often dominates male production. However, most studies in bumblebees have been conducted with only a few selected, mostly single mated species from temperate climate regions. Here we study the genetic colony composition of the facultative polyandrous neotropical bumblebee Bombus wilmattae, to assess the outcome of the queen-worker conflict over male production and to detect potential worker policing. Results A total of 120 males from five colonies were genotyped with up to nine microsatellite markers to infer their parentage. Four of the five colonies were queen right at point of time of male sampling, while one had an uncertain queen status. The workers clearly dominated production of males with an average of 84.9% +/- 14.3% of males being worker sons. In the two doubly mated colonies 62.5% and 96.7% of the male offspring originated from workers and both patrilines participated in male production. Inferring the mother genotypes from the male offspring, between four to eight workers participated in the production of males. Conclusions In this study we show that the workers clearly win the queen-worker conflict over male production in B. wilmattae, which sets them apart from the temperate bumblebee species studied so far. Workers clearly dominated male production in the singly as well the doubly mated colonies, with up to eight workers producing male offspring in a single colony. Moreover no monopolization of reproduction by single workers occurred.

  13. Culture shapes a mesolimbic response to signals of dominance and subordination that associates with behavior.

    Science.gov (United States)

    Freeman, Jonathan B; Rule, Nicholas O; Adams, Reginald B; Ambady, Nalini

    2009-08-01

    It has long been understood that culture shapes individuals' behavior, but how this is accomplished in the human brain has remained largely unknown. To examine this, we made use of a well-established cross-cultural difference in behavior: American culture tends to reinforce dominant behavior whereas, conversely, Japanese culture tends to reinforce subordinate behavior. In 17 Americans and 17 Japanese individuals, we assessed behavioral tendencies towards dominance versus subordination and measured neural responses using fMRI during the passive viewing of stimuli related to dominance and subordination. In Americans, dominant stimuli selectively engaged the caudate nucleus, bilaterally, and the medial prefrontal cortex (mPFC), whereas these were selectively engaged by subordinate stimuli in Japanese. Correspondingly, Americans self-reported a tendency towards more dominant behavior whereas Japanese self-reported a tendency towards more subordinate behavior. Moreover, activity in the right caudate and mPFC correlated with behavioral tendencies towards dominance versus subordination, such that stronger responses in the caudate and mPFC to dominant stimuli were associated with more dominant behavior and stronger responses in the caudate and mPFC to subordinate stimuli were associated with more subordinate behavior. The findings provide a first demonstration that culture can flexibly shape functional activity in the mesolimbic reward system, which in turn may guide behavior.

  14. MONITORING CANOPY AND AIR TEMPERATURE OF DOMINANT VEGETATION IN TROPICAL SEMI-ARID USING BIOCLIMATIC MODEL

    Directory of Open Access Journals (Sweden)

    Josiclêda Domiciano Galvíncio

    2016-10-01

    Full Text Available Typical vegetation of arid environments consist of few dominant species highly threatened by climate change. Jurema preta (Mimosa tenuiflora (Willd. Poiret is one of these successful species that now is dominant in extensive semiarid areas in the world. The development of a simple bioclimatic model using climate change scenarios based on optimistic and pessimistic predictions of the Intergovernmental Panel on Climate Change (IPCC shown as a simple tool to predict possible responses of dominant species under dry land conditions and low functional biodiversity. The simple bioclimatic model proved satisfactory in creating climate change scenarios and impacts on the canopy temperature of Jurema preta in semiarid Brazil. The bioclimatic model was efficient to obtain spatially relevant estimations of air temperature from determinations of the surface temperature using satellite images. The model determined that the average difference of 5oC between the air temperature and the leaf temperature for Jurema preta, and an increase of 3oC in air temperature, promote an increase of 2oC in leaf temperature. It lead to disturbances in vital physiological mechanisms in the leaf, mainly the photosynthesis and efficient use of water.

  15. Can a native rodent species limit the invasive potential of a non-native rodent species in tropical agroforest habitats?

    Science.gov (United States)

    Stuart, Alexander M; Prescott, Colin V; Singleton, Grant R

    2016-06-01

    Little is known about native and non-native rodent species interactions in complex tropical agroecosystems. We hypothesised that the native non-pest rodent Rattus everetti may be competitively dominant over the invasive pest rodent Rattus tanezumi within agroforests. We tested this experimentally by using pulse removal for three consecutive months to reduce populations of R. everetti in agroforest habitat, and assessed over 6 months the response of R. tanezumi and other rodent species. Following removal, R. everetti individuals rapidly immigrated into removal sites. At the end of the study period, R. tanezumi were larger and there was a significant shift in their microhabitat use with respect to the use of ground vegetation cover following the perturbation of R. everetti. Irrespective of treatment, R. tanezumi selected microhabitat with less tree canopy cover, indicative of severely disturbed habitat, whereas R. everetti selected microhabitat with a dense canopy. Our results suggest that sustained habitat disturbance in agroforests favours R. tanezumi, while the regeneration of agroforests towards a more natural state would favour native species and may reduce pest pressure in adjacent crops. In addition, the rapid recolonisation of R. everetti suggests this species would be able to recover from non-target impacts of short-term rodent pest control. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  16. The consequences of time averaging for measuring temporal species turnover in the fossil record

    Science.gov (United States)

    Tomašových, Adam; Kidwell, Susan

    2010-05-01

    Modeling time averaging effects with simple simulations allows us to evaluate the magnitude of change in temporal species turnover that is expected to occur in long (paleoecological) time series with fossil assemblages. Distinguishing different modes of metacommunity dynamics (such as neutral, density-dependent, or trade-off dynamics) with time-averaged fossil assemblages requires scaling-up time-averaging effects because the decrease in temporal resolution and the decrease in temporal inter-sample separation (i.e., the two main effects of time averaging) substantially increase community stability relative to assemblages without or with weak time averaging. Large changes in temporal scale that cover centuries to millennia can lead to unprecedented effects on temporal rate of change in species composition. Temporal variation in species composition monotonically decreases with increasing duration of time-averaging in simulated fossil assemblages. Time averaging is also associated with the reduction of species dominance owing to the temporal switching in the identity of dominant species. High degrees of time averaging can cause that community parameters of local fossil assemblages converge to parameters of metacommunity rather that to parameters of individual local non-averaged communities. We find that the low variation in species composition observed among mollusk and ostracod subfossil assemblages can be explained by time averaging alone, and low temporal resolution and reduced temporal separation among assemblages in time series can thus explain a substantial part of the reduced variation in species composition relative to unscaled predictions of neutral model (i.e., species do not differ in birth, death, and immigration rates on per capita basis). The structure of time-averaged assemblages can thus provide important insights into processes that act over larger temporal scales, such as evolution of niches and dispersal, range-limit dynamics, taxon cycles, and

  17. Different Patterns of Changes in the Dry Season Diameter at Breast Height of Dominant and Evergreen Tree Species in a Mature Subtropical Forest in South China

    Institute of Scientific and Technical Information of China (English)

    Jun-Hua Yan; Guo-Yi Zhou; De-Qiang Zhang; Xu-Li Tang; Xu Wang

    2006-01-01

    Information on changes in diameter at breast height (DBH) is important for net primary production (NPP)estimates, timing of forest inventory, and forest management. In the present study, patterns of DBH change were measured under field conditions during the dry season for three dominant and native tree species in a monsoon evergreen broad-leaved forest in the Dinghushan Biosphere Reserve. For each tree species,different patterns of DBH change were observed. In the case of the fast-growing tree species Castanopsis chinensis Hance, large diurnal fluctuations occur, with a peak DBH in the early morning (around 05:00 h) that decreases to a minimum by about 14:00 h. Both Schima superba Gardn. et Chemp and Cryptocarya chinensis (Hance) Hemsl. exhibited less diurnal swelling and shrinkage. Diurnal fluctuations for these species were observed on a few occasions over the period of observation. Graphical comparisons and statistical analysis of changes in DBH with meteorological variables indicate that for different trees, the different changes in DBH observed responded to different meteorological variables. Large stem changes were found to occur for Ca. chinensis trees that were associated with variations in solar radiation. However, both S. superba and Cr. chinensis were found to be less sensitive to solar radiation. Changes in the DBH of these two species were found to be controlled mainly by soil temperature and soil moisture. During the later dry season, with a lower soil temperature and soil moisture, all three tree species stopped growing and only negligible shrinkage, expansion, or fluctuation occurred, suggesting that the optimum time to measure tree growth in the Dinghushan Biosphere Reserve is the later dry season.

  18. Effects of processing on proximate and fatty acid compositions of six commercial sea cucumber species of Sri Lanka.

    Science.gov (United States)

    Nishanthan, G; Kumara, P A D A; de Croos, M D S T; Prasada, D V P; Dissanayake, D C T

    2018-05-01

    Processing and its impacts on proximate composition and fatty acid profile of six sea cucumber species; Bohadschia marmorata, Stichopus chloronotus, Holothuria spinifera, Thelenota anax, Holothuria scabra and Bohadschia sp. 1 collected from the northwest coast of Sri Lanka were analyzed. Sea cucumbers are processed into bêche - de - mer by both domestic and industrial level processors following the similar steps of cleaning, evisceration, first boiling, salting, second boiling and drying. However, domestically processed bêche - de - mer always reported a higher percentage of moisture, crude ash, crude fat and lower percentage of crude protein than industrially processed products. Although processing resulted in a significant reduction of total SFA and MUFA in fresh individuals of most of these species, total PUFA increased significantly in processed individuals excluding Bohadschia species. Palmitic acid was found to be the most dominant fatty acid in all these species followed by eicosapentaenoic acid, which showed a significant increase in processed products, except Bohadschia sp. 1. Total MUFA were higher than total SFA in all sea cucumber species having exceptions in Bohadchia sp.1 and fresh S. chloronotus. These findings will make a significant contribution to fill the gaps in existing information as no any previous information is available for species like H. spinifera and S. chloronotus .

  19. Individual and species-specific traits explain niche size and functional role in spiders as generalist predators.

    Science.gov (United States)

    Sanders, Dirk; Vogel, Esther; Knop, Eva

    2015-01-01

    The function of a predator within a community is greatly based on its trophic niche, that is the number and the strength of feeding links. In generalist predators, which feed on a wide range of prey, the size and position of the trophic niche is likely determined by traits such as hunting mode, the stratum they occur in, their body size and age. We used stable isotope analyses ((13)C and (15)N) to measure the trophic niche size of nine spider species within a forest hedge community and tested for species traits and individual traits that influence stable isotope enrichment, niche size and resource use. The spiders Enoplognatha, Philodromus, Floronia, and Heliophanus had large isotopic niches, which correspond to a more generalistic feeding behaviour. In contrast, Araneus, Metellina and Agelena, as top predators in the system, had rather narrow niches. We found a negative correlation between trophic position and niche size. Differences in trophic position in spiders were explained by body size, hunting modes and stratum, while niche size was influenced by hunting mode. In Philodromus, the size of the trophic niche increased significantly with age. Fitting spiders to functional groups according to their mean body size, hunting mode and their habitat domain resulted in largely separated niches, which indicates that these traits are meaningful for separating functional entities in spiders. Functional groups based on habitat domain (stratum) caught the essential functional differences between the species with species higher up in the vegetation feeding on flying insects and herb and ground species also preying on forest floor decomposers. Interestingly, we found a gradient from large species using a higher habitat domain and having a smaller niche to smaller species foraging closer to the ground and having a larger niche. This shows that even within generalist predators, such as spiders, there is a gradient of specialism that can be predicted by functional traits.

  20. The Relationship between the Brexit Vote and Individual Predictors of Prejudice: Collective Narcissism, Right Wing Authoritarianism, Social Dominance Orientation

    Science.gov (United States)

    Golec de Zavala, Agnieszka; Guerra, Rita; Simão, Cláudia

    2017-01-01

    The Leave campaign in the U.K., which advocated exiting the European Union, emphasized anxiety over immigration and the need to take control of the U.K.'s borders. Citizens who expressed concerns about immigration to the U.K. were more likely to vote to leave. Two correlational studies examined the previously unexplored question of whether the Brexit vote and support for the outcome of the E.U. referendum were linked to individual predictors of prejudice toward foreigners: British collective narcissism (a belief in national greatness), right wing authoritarianism, and social dominance orientation. The results converged to indicate that all three variables were independently related to the perceived threat of immigrants and, via this variable, to the Brexit vote and a support for the outcome of the E.U. referendum. These variables explained the variance in the perceived threat of immigrants and support for the Brexit vote over and above other previously examined predictors such as age, education, or ethnicity, as well as, national identification and national attachment. PMID:29230185

  1. The Relationship between the Brexit Vote and Individual Predictors of Prejudice: Collective Narcissism, Right Wing Authoritarianism, Social Dominance Orientation

    Directory of Open Access Journals (Sweden)

    Agnieszka Golec de Zavala

    2017-11-01

    Full Text Available The Leave campaign in the U.K., which advocated exiting the European Union, emphasized anxiety over immigration and the need to take control of the U.K.'s borders. Citizens who expressed concerns about immigration to the U.K. were more likely to vote to leave. Two correlational studies examined the previously unexplored question of whether the Brexit vote and support for the outcome of the E.U. referendum were linked to individual predictors of prejudice toward foreigners: British collective narcissism (a belief in national greatness, right wing authoritarianism, and social dominance orientation. The results converged to indicate that all three variables were independently related to the perceived threat of immigrants and, via this variable, to the Brexit vote and a support for the outcome of the E.U. referendum. These variables explained the variance in the perceived threat of immigrants and support for the Brexit vote over and above other previously examined predictors such as age, education, or ethnicity, as well as, national identification and national attachment.

  2. Carbon Dioxide Physiological Forcing Dominates Projected Eastern Amazonian Drying

    Science.gov (United States)

    Richardson, T. B.; Forster, P. M.; Andrews, T.; Boucher, O.; Faluvegi, G.; Fläschner, D.; Kasoar, M.; Kirkevâg, A.; Lamarque, J.-F.; Myhre, G.; Olivié, D.; Samset, B. H.; Shawki, D.; Shindell, D.; Takemura, T.; Voulgarakis, A.

    2018-03-01

    Future projections of east Amazonian precipitation indicate drying, but they are uncertain and poorly understood. In this study we analyze the Amazonian precipitation response to individual atmospheric forcings using a number of global climate models. Black carbon is found to drive reduced precipitation over the Amazon due to temperature-driven circulation changes, but the magnitude is uncertain. CO2 drives reductions in precipitation concentrated in the east, mainly due to a robustly negative, but highly variable in magnitude, fast response. We find that the physiological effect of CO2 on plant stomata is the dominant driver of the fast response due to reduced latent heating and also contributes to the large model spread. Using a simple model, we show that CO2 physiological effects dominate future multimodel mean precipitation projections over the Amazon. However, in individual models temperature-driven changes can be large, but due to little agreement, they largely cancel out in the model mean.

  3. Edaphic, salinity, and stand structural trends in chronosequences of native and non-native dominated riparian forests along the Colorado River, USA

    Science.gov (United States)

    Merritt, David M.; Shafroth, Patrick B.

    2012-01-01

    Tamarix spp. are introduced shrubs that have become among the most abundant woody plants growing along western North American rivers. We sought to empirically test the long-held belief that Tamarix actively displaces native species through elevating soil salinity via salt exudation. We measured chemical and physical attributes of soils (e.g., salinity, major cations and anions, texture), litter cover and depth, and stand structure along chronosequences dominated by Tamarix and those dominated by native riparian species (Populus or Salix) along the upper and lower Colorado River in Colorado and Arizona/California, USA. We tested four hypotheses: (1) the rate of salt accumulation in soils is faster in Tamarix-dominated stands than stands dominated by native species, (2) the concentration of salts in the soil is higher in mature stands dominated by Tamarix compared to native stands, (3) soil salinity is a function of Tamarix abundance, and (4) available nutrients are more concentrated in native-dominated stands compared to Tamarix-dominated stands. We found that salt concentration increases at a faster rate in Tamarix-dominated stands along the relatively free-flowing upper Colorado but not along the heavily-regulated lower Colorado. Concentrations of ions that are known to be preferentially exuded by Tamarix (e.g., B, Na, and Cl) were higher in Tamarix stands than in native stands. Soil salt concentrations in older Tamarix stands along the upper Colorado were sufficiently high to inhibit germination, establishment, or growth of some native species. On the lower Colorado, salinity was very high in all stands and is likely due to factors associated with floodplain development and the hydrologic effects of river regulation, such as reduced overbank flooding, evaporation of shallow ground water, higher salt concentrations in surface and ground water due to agricultural practices, and higher salt concentrations in fine-textured sediments derived from naturally saline

  4. Structural determination of individual chemical species in a mixed system by iterative transformation factor analysis-based X-ray absorption spectroscopy combined with UV-visible absorption and quantum chemical calculation.

    Science.gov (United States)

    Ikeda, Atsushi; Hennig, Christoph; Rossberg, André; Tsushima, Satoru; Scheinost, Andreas C; Bernhard, Gert

    2008-02-15

    A multitechnique approach using extended X-ray absorption fine structure (EXAFS) spectroscopy based on iterative transformation factor analysis (ITFA), UV-visible absorption spectroscopy, and density functional theory (DFT) calculations has been performed in order to investigate the speciation of uranium(VI) nitrate species in acetonitrile and to identify the complex structure of individual species in the system. UV-visible spectral titration suggests that there are four different species in the system, that is, pure solvated species, mono-, di-, and trinitrate species. The pure EXAFS spectra of these individual species are extracted by ITFA from the measured spectral mixtures on the basis of the speciation distribution profile calculated from the UV-visible data. Data analysis of the extracted EXAFS spectra, with the help of DFT calculations, reveals the most probable complex structures of the individual species. The pure solvated species corresponds to a uranyl hydrate complex with an equatorial coordination number (CNeq) of 5, [UO2(H2O)5]2+. Nitrate ions tend to coordinate to the uranyl(VI) ion in a bidentate fashion rather than a unidentate one in acetonitrile for all the nitrate species. The mononitrate species forms the complex of [UO2(H2O)3NO3]+ with a CNeq value of 5, while the di- and trinitrate species have a CNeq value of 6, corresponding to [UO2(H2O)2(NO3)2]0 (D2h) and [UO2(NO3)3]- (D3h), respectively.

  5. Limited impacts of extensive human land use on dominance, specialization, and biotic homogenization in boreal plant communities.

    Science.gov (United States)

    Mayor, Stephen J; Boutin, Stan; He, Fangliang; Cahill, James F

    2015-02-13

    Niche theory predicts that human disturbance should influence the assembly of communities, favouring functionally homogeneous communities dominated by few but widespread generalists. The decline and loss of specialists leaves communities with species that are functionally more similar. Evenness of species occupancy declines, such that species become either widespread of rare. These patterns have often been observed, but it is unclear if they are a general result of human disturbance or specific to communities that are rich in species, in complex, spatially heterogeneous environments where the problem has often been investigated. We therefore tested whether human disturbance impacts dominance/evenness of species occupancy in communities, specialism/generalism of species, and functional biotic homogenization in the spatially relatively homogeneous, species poor boreal forest region of Alberta, Canada. We investigated 371 boreal vascular plant communities varying 0 - 100% in proportion of human land use. Rank species occupancy curves revealed high species dominance regardless of disturbance: within any disturbance class a few species occupied nearly every site and most species were found in a low proportion of sites. However, species were more widespread and displayed more even occupancy in intermediately disturbed communities than among communities of either low or high disturbance. We defined specialists and generalists based on turnover in co-occupants and thereby assessed impacts of human disturbance on specialization of species and community homogenization. Generalists were not disproportionately found at higher disturbance sites, and did not occupy more sites. Communities with greater human disturbance were not more functionally homogeneous; they did not harbor communities with more generalists. We unexpectedly did not observe strong linkages between species specialism/generalism and disturbance, nor between community homogenization and disturbance. These

  6. Human infants' learning of social structures: the case of dominance hierarchy.

    Science.gov (United States)

    Mascaro, Olivier; Csibra, Gergely

    2014-01-01

    We tested 15-month-olds' capacity to represent social-dominance hierarchies with more than two agents. Our results showed that infants found it harder to memorize dominance relations that were presented in an order that hindered the incremental formation of a single structure (Study 1). These results suggest that infants attempt to build structures incrementally, relation by relation, thereby simplifying the complex problem of recognizing a social structure. Infants also found circular dominance structures harder to process than linear dominance structures (Study 2). These expectations about the shape of structures may facilitate learning. Our results suggest that infants attempt to represent social structures composed of social relations. They indicate that human infants go beyond learning about individual social partners and their respective relations and form hypotheses about how social groups are organized.

  7. Social dominance modulates eavesdropping in zebrafish

    Science.gov (United States)

    Abril-de-Abreu, Rodrigo; Cruz, Ana S.; Oliveira, Rui F.

    2015-01-01

    Group living animals may eavesdrop on signalling interactions between conspecifics and integrate it with their own past social experience in order to optimize the use of relevant information from others. However, little is known about this interplay between public (eavesdropped) and private social information. To investigate it, we first manipulated the dominance status of bystander zebrafish. Next, we either allowed or prevented bystanders from observing a fight. Finally, we assessed their behaviour towards the winners and losers of the interaction, using a custom-made video-tracking system and directional analysis. We found that only dominant bystanders who had seen the fight revealed a significant increase in directional focus (a measure of attention) towards the losers of the fights. Furthermore, our results indicate that information about the fighters' acquired status was collected from the signalling interaction itself and not from post-interaction status cues, which implies the existence of individual recognition in zebrafish. Thus, we show for the first time that zebrafish, a highly social model organism, eavesdrop on conspecific agonistic interactions and that this process is modulated by the eavesdroppers' dominance status. We suggest that this type of integration of public and private information may be ubiquitous in social learning processes. PMID:26361550

  8. Relating 2-Rainbow Domination To Roman Domination

    Directory of Open Access Journals (Sweden)

    Alvarado José D.

    2017-11-01

    Full Text Available For a graph G, let R(G and yr2(G denote the Roman domination number of G and the 2-rainbow domination number of G, respectively. It is known that yr2(G ≤ R(G ≤ 3/2yr2(G. Fujita and Furuya [Difference between 2-rainbow domination and Roman domination in graphs, Discrete Appl. Math. 161 (2013 806-812] present some kind of characterization of the graphs G for which R(G − yr2(G = k for some integer k. Unfortunately, their result does not lead to an algorithm that allows to recognize these graphs efficiently. We show that for every fixed non-negative integer k, the recognition of the connected K4-free graphs G with yR(G − yr2(G = k is NP-hard, which implies that there is most likely no good characterization of these graphs. We characterize the graphs G such that yr2(H = yR(H for every induced subgraph H of G, and collect several properties of the graphs G with R(G = 3/2yr2(G.

  9. Helminth communities of two species of piscivorous birds, Ardea alba (Linnaeus) and Nyctanassa violacea (Gmelin) (Ciconiiformes: Ardeidae), in two coastal lagoons from Guerrero state, Mexico.

    Science.gov (United States)

    Violante-González, Juan; Monks, Scott; Gil-Guerrero, Salvador; Rojas-Herrera, Agustín A; Flores-Rodríguez, Pedro

    2012-07-01

    The composition and species richness in helminth communities of two species of heron, Ardea alba and Nyctanassa violacea, in two coastal lagoons from Guerrero, Mexico were examined. Nineteen species of helminth (7,804 individuals) were identified in 43 adult birds: 15 digeneans, 1 acanthocephalan, 1 cestode, and 2 nematodes. Eight species co-occurred in herons of both species and lagoons. The prevalence values of seven species and the mean abundance of five species varied significantly between species of birds and between lagoons. The heterophyid, Ascocotyle (Phagicola) longa, was the helminth numerically dominant in the helminth community of A. alba in both lagoons, while the cestode, Parvitaenia cochlearii, dominated the community of N. violacea. At the component community level, species richness varied significantly: 10 species in A. alba from Coyuca to 16 in N. violacea (Tres Palos). All of the birds examined were infected with helminth parasites: three to seven species per host in A. alba from Coyuca, and two to eight species in A. alba and N. violacea from Tres Palos. The results indicate that even though species composition was similar between both species of heron, the structure of their communities was not the same. Differences in the feeding behavior of the birds (day/night habits), as well as local differences in the abundance of species of fish, and infection levels of helminths in each lagoon are suggested as being responsible for the variations registered in the structure of the helminth communities.

  10. Molecular Diagnostics in Autosomal Dominant Polycystic Kidney Disease: Utility and Limitations

    Science.gov (United States)

    Zhao, Xiao; Paterson, Andrew D.; Zahirieh, Alireza; He, Ning; Wang, Kairong; Pei, York

    2008-01-01

    Background and objectives: Gene-based mutation screening is now available and has the potential to provide diagnostic confirmation or exclusion of autosomal dominant polycystic kidney disease. This study illustrates its utility and limitations in the clinical setting. Design, setting, participants, & measurements: Using a molecular diagnostic service, genomic DNA of one affected individual from each study family was screened for pathologic PKD1 and PKD2 mutations. Bidirectional sequencing was performed to identify sequence variants in all exons and splice junctions of both genes and to confirm the specific mutations in other family members. In two multiplex families, microsatellite markers were genotyped at both PDK1 and PKD2 loci, and pair-wise and multipoint linkage analysis was performed. Results: Three of five probands studied were referred for assessment of renal cystic disease without a family history of autosomal dominant polycystic kidney disease, and two others were younger at-risk members of families with autosomal dominant polycystic kidney disease being evaluated as living-related kidney donors. Gene-based mutation screening identified pathogenic mutations that provided confirmation or exclusion of disease in three probands, but in the other two, only unclassified variants were identified. In one proband in which mutation screening was indeterminate, DNA linkage studies provided strong evidence for disease exclusion. Conclusions: Gene-based mutation screening or DNA linkage analysis should be considered in individuals in whom the diagnosis of autosomal dominant polycystic kidney disease is uncertain because of a lack of family history or equivocal imaging results and in younger at-risk individuals who are being evaluated as living-related kidney donors. PMID:18077784

  11. Genetic origin and composition of a natural hybrid poplar Populus × jrtyschensis from two distantly related species.

    Science.gov (United States)

    Jiang, Dechun; Feng, Jianju; Dong, Miao; Wu, Guili; Mao, Kangshan; Liu, Jianquan

    2016-04-18

    The factors that contribute to and maintain hybrid zones between distinct species are highly variable, depending on hybrid origins, frequencies and fitness. In this study, we aimed to examine genetic origins, compositions and possible maintenance of Populus × jrtyschensis, an assumed natural hybrid between two distantly related species. This hybrid poplar occurs mainly on the floodplains along the river valleys between the overlapping distributions of the two putative parents. We collected 566 individuals from 45 typical populations of P. × jrtyschensis, P. nigra and P. laurifolia. We genotyped them based on the sequence variations of one maternally inherited chloroplast DNA (cpDNA) fragment and genetic polymorphisms at 20 SSR loci. We further sequenced eight nuclear genes for 168 individuals from 31 populations. Two groups of cpDNA haplotypes characteristic of P. nigra and P. laurifolia respectively were both recovered for P. × jrtyschensis. Genetic structures and coalescent tests of two sets of nuclear population genetic data suggested that P. × jrtyschensis originated from hybridizations between the two assumed parental species. All examined populations of P. × jrtyschensis comprise mainly F1 hybrids from interspecific hybridizations between P. nigra and P. laurifolia. In the habitats of P. × jrtyschensis, there are lower concentrations of soil nitrogen than in the habitats occupied by the other two species. Our extensive examination of the genetic composition of P. × jrtyschensis suggested that it is typical of F1-dominated hybrid zones. This finding plus the low concentration of soil nitrogen in the floodplain soils support the F1-dominated bounded hybrid superiority hypothesis of hybrid zone maintenance for this particular hybrid poplar.

  12. Grain Unloading Of Arsenic Species In Rice

    Science.gov (United States)

    Rice (Oryza sativa) is the staple food for over half the world's population yet may represent a significant dietary source of inorganic arsenic (As), a nonthreshold, class 1 human carcinogen. Rice grain As is dominated by the inorganic species, and the organic species dim...

  13. Transplanting native dominant plants to facilitate community development in restored coastal plain wetlands.

    Energy Technology Data Exchange (ETDEWEB)

    De Steven, Diane; Sharitz, Rebecca R.

    2007-12-01

    Abstract: Drained depressional wetlands are typically restored by plugging ditches or breaking drainage tiles to allow recovery of natural ponding regimes, while relying on passive recolonization from seed banks and dispersal to establish emergent vegetation. However, in restored depressions of the southeastern United States Coastal Plain, certain characteristic rhizomatous graminoid species may not recolonize because they are dispersal-limited and uncommon or absent in the seed banks of disturbed sites. We tested whether selectively planting such wetland dominants could facilitate restoration by accelerating vegetative cover development and suppressing non-wetland species. In an operational-scale project in a South Carolina forested landscape, drained depressional wetlands were restored in early 2001 by completely removing woody vegetation and plugging surface ditches. After forest removal, tillers of two rhizomatous wetland grasses (Panicum hemitomon, Leersia hexandra) were transplanted into singlespecies blocks in 12 restored depressions that otherwise were revegetating passively. Presence and cover of all plant species appearing in planted plots and unplanted control plots were recorded annually. We analyzed vegetation composition after two and four years, during a severe drought (2002) and after hydrologic recovery (2004). Most grass plantings established successfully, attaining 15%–85% cover in two years. Planted plots had fewer total species and fewer wetland species compared to control plots, but differences were small. Planted plots achieved greater total vegetative cover during the drought and greater combined cover of wetland species in both years. By 2004, planted grasses appeared to reduce cover of non-wetland species in some cases, but wetter hydrologic conditions contributed more strongly to suppression of non-wetland species. Because these two grasses typically form a dominant cover matrix in herbaceous depressions, our results indicated that

  14. Distribution and community structure of ichthyoplankton in Laguna Madre seagrass meadows: Potential impact of seagrass species change

    Science.gov (United States)

    Tolan, J.M.; Holt, S.A.; Onuf, C.P.

    1997-01-01

    Seasonal ichthyoplankton surveys were made in the lower Laguna Madre, Texas, to compare the relative utilization of various nursery habitats (shoal grass, Halodule wrightii; manatee grass, Syringodium filiforme;, and unvegetated sand bottom) for both estuarine and offshore-spawned larvae. The species composition and abundance of fish larvae were determined for each habitat type at six locations in the bay. Pushnet ichthyoplankton sampling resulted in 296 total collections, yielding 107,463 fishes representing 55 species in 24 families. A broad spectrum of both the biotic and physical habitat parameters were examined to link the dispersion and distribution of both pre-settlement and post-settlement larvae to the utilization of shallow seagrass habitats. Sample sites were grouped by cluster analysis (Ward's minimum variance method) according to the similarity of their fish assemblages and subsequently examined with a multiple discriminant function analysis to identify important environmental variables. Abiotic environmental factors were most influential in defining groups for samples dominated by early larvae, whereas measures of seagrass complexity defined groups dominated by older larvae and juveniles. Juvenile-stage individuals showed clear habitat preference, with the more shallow Halodule wrightii being the habitat of choice, whereas early larvae of most species were widely distributed over all habitats. As a result of the recent shift of dominance from Halodule wrightii to Syringodium filiforme, overall reductions in the quality of nursery habitat for fishes in the lower Laguna Madre are projected.

  15. Asymmetry in species regional dispersal ability and the neutral theory.

    Directory of Open Access Journals (Sweden)

    Jiajia Liu

    Full Text Available The neutral assumption that individuals of either the same or different species share exactly the same birth, death, migration, and speciation probabilities is fundamental yet controversial to the neutral theory. Several theoretical studies have demonstrated that a slight difference in species per capita birth or death rates can have a profound consequence on species coexistence and community structure. Whether asymmetry in migration, a vital demographic parameter in the neutral model, plays an important role in community assembly still remains unknown. In this paper, we relaxed the ecological equivalence assumption of the neutral model by introducing differences into species regional dispersal ability. We investigated the effect of asymmetric dispersal on the neutral local community structure. We found that per capita asymmetric dispersal among species could reduce species richness of the local community and result in deviations of species abundance distributions from those predicted by the neutral model. But the effect was moderate compared with that of asymmetries in birth or death rates, unless very large asymmetries in dispersal were assumed. A large difference in species dispersal ability, if there is, can overwhelm the role of random drift and make local community dynamics deterministic. In this case, species with higher regional dispersal abilities tended to dominate in the local community. However, the species abundance distribution of the local community under asymmetric dispersal could be well fitted by the neutral model, but the neutral model generally underestimated the fundamental biodiversity number but overestimated the migration rate in such communities.

  16. Ecological implications of reduced pollen deposition in alpine plants: a case study using a dominant cushion plant species.

    Science.gov (United States)

    Reid, Anya; Hooper, Robyn; Molenda, Olivia; Lortie, Christopher J

    2014-01-01

    The reproductive assurance hypothesis states that self-incompatible female plants must produce twice the number of seeds relative to their self-compatible hermaphroditic counterparts to persist in gynodioecious populations. This is a viable life-history strategy, provided that pollination rates are sufficiently high. However, reduced pollination rates in alpine plants are likely due to climate induced plant-pollinator mismatches and general declines in pollinators. Using a gynodioecious population of the dominant plant Silene acaulis (Caryophyllaceae), we tested the reproductive assurance hypothesis and also the stress gradient hypothesis with a series of pollinator exclusion trials and extensive measurements of subsequent reproductive output (gender ratio, plant size, percent fruit-set, fruit weight, seeds per fruit, total seeds, seed weight, and seed germination). The reproductive assurance hypothesis was supported with female plants being more sensitive to and less likely to be viable under reductions in pollination rates. These findings are the first to show that the stress gradient hypothesis is also supported under a gradient of pollen supply instead of environmental limitations. Beneficiary abundance was negatively correlated to percent fruit-set under current pollen supply, but became positive under reduced pollen supply suggesting that there are important plant-plant-pollinator interactions related to reproduction in these alpine plant species.

  17. Projected shifts in fish species dominance in Wisconsin lakes under climate change

    Science.gov (United States)

    Hansen, Gretchen JA; Read, Jordan S.; Hansen, Jonathan F.; Winslow, Luke

    2016-01-01

    Temperate lakes may contain both coolwater fish species such as walleye (Sander vitreus) and warmwater fish species such as largemouth bass (Micropterus salmoides). Recent declining walleye and increasing largemouth bass populations have raised questions regarding the future trajectories and management actions for these species. We developed a thermodynamic model of water temperatures driven by downscaled climate data and lake-specific characteristics to estimate daily water temperature profiles for 2148 lakes in Wisconsin, US, under contemporary (1989–2014) and future (2040–2064 and 2065–2089) conditions. We correlated contemporary walleye recruitment and largemouth bass relative abundance to modeled water temperature, lake morphometry, and lake productivity, and projected lake-specific changes in each species under future climate conditions. Walleye recruitment success was negatively related and largemouth bass abundance was positively related to water temperature degree days. Both species exhibited a threshold response at the same degree day value, albeit in opposite directions. Degree days were predicted to increase in the future, although the magnitude of increase varied among lakes, time periods, and global circulation models (GCMs). Under future conditions, we predicted a loss of walleye recruitment in 33–75% of lakes where recruitment is currently supported and a 27–60% increase in the number of lakes suitable for high largemouth bass abundance. The percentage of lakes capable of supporting abundant largemouth bass but failed walleye recruitment was predicted to increase from 58% in contemporary conditions to 86% by mid-century and to 91% of lakes by late century, based on median projections across GCMs. Conversely, the percentage of lakes with successful walleye recruitment and low largemouth bass abundance was predicted to decline from 9% of lakes in contemporary conditions to only 1% of lakes in both future periods. Importantly, we identify up

  18. [New species, newly used names and new ranges of tree ferns (Filicales: Cyatheaceae) in the Neotropics].

    Science.gov (United States)

    Rojas-Alvarado, A F

    2001-06-01

    Two new species are described for the Neotropics, four species are newly accepted, and four species and one variety are reported. The new species are: Cyathea grayumii A. Rojas and C. panamensis A. Rojas. Cyathea alfonsiana L. D. Gómez, C. holdridgeana Nisman & L. D. Gómez, C. onusta H. Christ and C. squarrosa (Rosenst.) Domin are recognized; Cnemidaria coclena Stolze, Cyathea andina (H. Karst.) Domin, C. caracasana var. meridensis (H. Karst.) R. M. Tryon, C. macrosora (Baker) Domin and C. pseudonanna (L. D. Gómez) Lellinger are reported from Costa Rica and Panama.

  19. Managing Japanese stiltgrass dominated communities in the ridge and valley physiographic province in eastern West Virginia

    Science.gov (United States)

    David W. McGill; William N. Grafton; Jonathan A. Pomp

    2008-01-01

    Japanese stiltgrass (Microstegium vimineum) is an exotic invasive species that can dominate forest understories and suppress native herbaceous and woody species. This study had two objectives: 1) to assess directed spray herbicides for controlling M. vimineum; and 2) to collect a set of factors that affect management of M...

  20. Impressions of Dominance are Made Relative to others in the Visual Environment

    Directory of Open Access Journals (Sweden)

    Daniel E. Re

    2014-01-01

    Full Text Available Face judgments of dominance play an important role in human social interaction. Perceived facial dominance is thought to indicate physical formidability, as well as resource acquisition and holding potential. Dominance cues in the face affect perceptions of attractiveness, emotional state, and physical strength. Most experimental paradigms test perceptions of facial dominance in individual faces, or they use manipulated versions of the same face in a forced-choice task but in the absence of other faces. Here, we extend this work by assessing whether dominance ratings are absolute or are judged relative to other faces. We presented participants with faces to be rated for dominance (target faces, while also presenting a second face (non-target faces that was not to be rated. We found that both the masculinity and sex of the non-target face affected dominance ratings of the target face. Masculinized non-target faces decreased the perceived dominance of a target face relative to a feminized non-target face, and displaying a male non-target face decreased perceived dominance of a target face more so than a female non-target face. Perceived dominance of male target faces was affected more by masculinization of male non-target faces than female non-target faces. These results indicate that dominance perceptions can be altered by surrounding faces, demonstrating that facial dominance is judged at least partly relative to other faces.

  1. Impressions of dominance are made relative to others in the visual environment.

    Science.gov (United States)

    Re, Daniel E; Lefevre, Carmen E; DeBruine, Lisa M; Jones, Benedict C; Perrett, David I

    2014-03-27

    Face judgments of dominance play an important role in human social interaction. Perceived facial dominance is thought to indicate physical formidability, as well as resource acquisition and holding potential. Dominance cues in the face affect perceptions of attractiveness, emotional state, and physical strength. Most experimental paradigms test perceptions of facial dominance in individual faces, or they use manipulated versions of the same face in a forced-choice task but in the absence of other faces. Here, we extend this work by assessing whether dominance ratings are absolute or are judged relative to other faces. We presented participants with faces to be rated for dominance (target faces), while also presenting a second face (non-target faces) that was not to be rated. We found that both the masculinity and sex of the non-target face affected dominance ratings of the target face. Masculinized non-target faces decreased the perceived dominance of a target face relative to a feminized non-target face, and displaying a male non-target face decreased perceived dominance of a target face more so than a female non-target face. Perceived dominance of male target faces was affected more by masculinization of male non-target faces than female non-target faces. These results indicate that dominance perceptions can be altered by surrounding faces, demonstrating that facial dominance is judged at least partly relative to other faces.

  2. Topics on domination

    CERN Document Server

    Hedetniemi, ST

    1991-01-01

    The contributions in this volume are divided into three sections: theoretical, new models and algorithmic. The first section focuses on properties of the standard domination number &ggr;(G), the second section is concerned with new variations on the domination theme, and the third is primarily concerned with finding classes of graphs for which the domination number (and several other domination-related parameters) can be computed in polynomial time.

  3. Vestibulo-cortical Hemispheric Dominance: the link between Anxiety and the Vestibular System?

    Science.gov (United States)

    Bednarczuk, Nadja F; Casanovas Ortega, Marta; Fluri, Anne-Sophie; Arshad, Qadeer

    2018-05-16

    Vestibular processing and anxiety networks are functionally intertwined, as demonstrated by reports of reciprocal influences upon each other. Yet whether there is an underlying link between these two systems remains unknown Previous findings have highlighted the involvement of hemispheric lateralisation in processing of both anxiety and vestibular signals. Accordingly, we explored the interaction between vestibular cortical processing and anxiety by assessing the relationship between anxiety levels and the degree of hemispheric lateralisation of vestibulo-cortical processing in 64 right-handed, healthy individuals. Vestibulo-cortical hemispheric lateralisation was determined by gaging the degree of caloric-induced nystagmus suppression following modulation of cortical excitability using trans-cranial direct current stimulation targeted over the posterior parietal cortex, an area implicated in the processing of vestibular signals. The degree of nystagmus suppression yields an objective biomarker, allowing the quantification of the degree of right vestibulo-cortical hemisphere dominance. Anxiety levels were quantified using the Trait component of the Spielberger State-Trait Anxiety Questionnaire. Our findings demonstrate that the degree of an individual's vestibulo-cortical hemispheric dominance correlates with their anxiety levels. That is, those individuals with greater right hemispheric vestibulo-cortical dominance exhibited lower levels of anxiety. By extension, our results support the notion that hemispheric lateralisation determines an individual's emotional processing, thereby linking cortical circuits involved in processing anxiety and vestibular signals respectively. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  4. The paired-domination and the upper paired-domination numbers of graphs

    Directory of Open Access Journals (Sweden)

    Włodzimierz Ulatowski

    2015-01-01

    Full Text Available In this paper we continue the study of paired-domination in graphs. A paired-dominating set, abbreviated PDS, of a graph \\(G\\ with no isolated vertex is a dominating set of vertices whose induced subgraph has a perfect matching. The paired-domination number of \\(G\\, denoted by \\(\\gamma_{p}(G\\, is the minimum cardinality of a PDS of \\(G\\. The upper paired-domination number of \\(G\\, denoted by \\(\\Gamma_{p}(G\\, is the maximum cardinality of a minimal PDS of \\(G\\. Let \\(G\\ be a connected graph of order \\(n\\geq 3\\. Haynes and Slater in [Paired-domination in graphs, Networks 32 (1998, 199-206], showed that \\(\\gamma_{p}(G\\leq n-1\\ and they determine the extremal graphs \\(G\\ achieving this bound. In this paper we obtain analogous results for \\(\\Gamma_{p}(G\\. Dorbec, Henning and McCoy in [Upper total domination versus upper paired-domination, Questiones Mathematicae 30 (2007, 1-12] determine \\(\\Gamma_{p}(P_n\\, instead in this paper we determine \\(\\Gamma_{p}(C_n\\. Moreover, we describe some families of graphs \\(G\\ for which the equality \\(\\gamma_{p}(G=\\Gamma_{p}(G\\ holds.

  5. Genomic Model with Correlation Between Additive and Dominance Effects.

    Science.gov (United States)

    Xiang, Tao; Christensen, Ole Fredslund; Vitezica, Zulma Gladis; Legarra, Andres

    2018-05-09

    Dominance genetic effects are rarely included in pedigree-based genetic evaluation. With the availability of single nucleotide polymorphism markers and the development of genomic evaluation, estimates of dominance genetic effects have become feasible using genomic best linear unbiased prediction (GBLUP). Usually, studies involving additive and dominance genetic effects ignore possible relationships between them. It has been often suggested that the magnitude of functional additive and dominance effects at the quantitative trait loci are related, but there is no existing GBLUP-like approach accounting for such correlation. Wellmann and Bennewitz showed two ways of considering directional relationships between additive and dominance effects, which they estimated in a Bayesian framework. However, these relationships cannot be fitted at the level of individuals instead of loci in a mixed model and are not compatible with standard animal or plant breeding software. This comes from a fundamental ambiguity in assigning the reference allele at a given locus. We show that, if there has been selection, assigning the most frequent as the reference allele orients the correlation between functional additive and dominance effects. As a consequence, the most frequent reference allele is expected to have a positive value. We also demonstrate that selection creates negative covariance between genotypic additive and dominance genetic values. For parameter estimation, it is possible to use a combined additive and dominance relationship matrix computed from marker genotypes, and to use standard restricted maximum likelihood (REML) algorithms based on an equivalent model. Through a simulation study, we show that such correlations can easily be estimated by mixed model software and accuracy of prediction for genetic values is slightly improved if such correlations are used in GBLUP. However, a model assuming uncorrelated effects and fitting orthogonal breeding values and dominant

  6. Service-Dominant Business Engineering with Base/X : Business Modeling Handbook

    NARCIS (Netherlands)

    Grefen, P.W.P.J.

    2015-01-01

    Many business domains are currently transitioning towards a service-dominant business setting. After the transition, business will be centered on the provisioning of solution-oriented, composed services to customers. The emphasis shifts from the value of the individual product or service to the

  7. What is materialism? Testing two dominant perspectives on materialism in the marketing literature

    Directory of Open Access Journals (Sweden)

    Manchiraju Srikant

    2015-09-01

    Full Text Available Materialism is defined as the importance an individual attaches to worldly possessions, which has been considered as an important construct in consumer behavior and marketing literature. There are two dominant perspectives on individual materialism in the marketing literature that focus on (1 personality traits or (2 individual personal values. However, several scholars have questioned the aforementioned materialism conceptualizations. Therefore, the present study directly compares the constructs of personality materialism and value materialism. Structural equation modeling was employed to address the following issues: (1 what are the key conceptual dimensions of materialism, (2 how much do they overlap, and (3 what is their discriminant validity in predicting outcomes linked to materialism. We suggest these two dominant perspectives on individual materialism are two distinct constructs, as they shared only 21 percent of common variance. Furthermore, we stress the multi-faceted nature of materialism, with an emphasis on future research directions related to materialism in marketing.

  8. Patterns and drivers of plant functional group dominance across the Western Hemisphere: a macroecological re-assessment based on a massive botanical dataset

    DEFF Research Database (Denmark)

    Jensen, Kristine Engemann; Sandel, Brody Steven; Enquist, Brian

    2016-01-01

    a standardized plant species occurrence dataset of unprecedented size covering the entire New World. Functional group distributions were estimated from 3 648 533 standardized occurrence records for a total of 83 854 vascular plant species, extracted from the Botanical Information and Ecology Network (BIEN......Plant functional group dominance has been linked to climate, topography and anthropogenic factors. Here, we assess existing theory linking functional group dominance patterns to their drivers by quantifying the spatial distribution of plant functional groups at a 100-km grid scale. We use......) database. Seven plant functional groups were considered, describing major differences in structure and function: epiphytes; climbers; ferns; herbs; shrubs; coniferous trees; and angiosperm trees. Two measures of dominance (relative number of occurrences and relative species richness) were analysed against...

  9. Considering transient population dynamics in the conservation of slow life-history species: An application to the sandhill crane

    Science.gov (United States)

    Gerber, Brian D.; Kendall, William L.

    2016-01-01

    The importance of transient dynamics of structured populations is increasingly recognized in ecology, yet these implications are not largely considered in conservation practices. We investigate transient and long-term population dynamics to demonstrate the process and utility of incorporating transient dynamics into conservation research and to better understand the population management of slow life-history species; these species can be theoretically highly sensitive to short- and long-term transient effects. We are specifically interested in the effects of anthropogenic removal of individuals from populations, such as caused by harvest, poaching, translocation, or incidental take. We use the sandhill crane (Grus canadensis) as an exemplar species; it is long-lived, has low reproduction, late maturity, and multiple populations are subject to sport harvest. We found sandhill cranes to have extremely high potential, but low likelihood for transient dynamics, even when the population is being harvested. The typically low population growth rate of slow life-history species appears to buffer against many perturbations causing large transient effects. Transient dynamics will dominate population trajectories of these species when stage structures are highly biased towards the younger and non-reproducing individuals, a situation that may be rare in established populations of long-lived animals. However, short-term transient population growth can be highly sensitive to vital rates that are relatively insensitive under equilibrium, suggesting that stage structure should be known if perturbation analysis is used to identify effective conservation strategies. For populations of slow life-history species that are not prone to large perturbations to their most productive individuals, population growth may be approximated by equilibrium dynamics.

  10. Brain Dominance And Speaking Strategy Use of Iranian EFL Learners

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    Nastaran Mireskandari

    2015-05-01

    Full Text Available The present study investigated the effect of brain dominance on the use of Language learning speaking strategies. One hundred forty two undergraduate students of Shiraz University, Iran, participated in this study. The Hemispheric Dominance Test (HDT was employed to categorize participants as right-, left- and whole-brain dominant, and a Speaking Strategy Questionnaire was administered to evaluate their use of speaking strategies. The results were analyzed using a one-way between groups analysis of variance (ANOVA to investigate whether there were any significant differences between the three brain dominant groups in their overall use of speaking strategies. A MANOVA was also run to investigate whether the groups had preferences regarding the use of any particular strategy type. Results indicated a statistically significant difference between the whole brain dominant participants and both left brain and right brain dominant learners for using compensation speaking strategies. To teach and learn more effectively, instructors and learners need to better understand and appreciate individual differences and how they can affect the learning process. They could find ways to combine activities that accommodate both left and right brain learners, employing not only the usual linear, verbal model, but also the active, image-rich, visuo-spatial models so that learners would be able to use both hemispheres.

  11. 137Cs and 40K activity in individuals of the mullet (Mugilidae) species Liza aurata from the South Adriatic sea

    International Nuclear Information System (INIS)

    Antovic, I.; Antovic, N. M.

    2009-01-01

    The results of the 137 Cs i 40 K activity measurements in whole individuals and some organs of the mullet species Liza aurata from the South Adriatic Sea, are presented. The measurements were performed in the non-coincidence mode of counting of the multidetector spectrometer PRIPYAT-2M. (author) [sr

  12. Natural endocrine profiles of the group-living skunk anemonefish Amphiprion akallopisos in relation to their size-based dominance hierarchy.

    Science.gov (United States)

    Mills, S C; O'Donnell, J L; Bernardi, G; Beldade, R

    2018-03-01

    Group-living animals commonly display differences in behaviour, physiology and endocrine profiles between conspecifics within the group, which are tightly linked to reproduction. Teleosts exhibit a variety of social systems, where social status, as well as sex, has been linked to different androgen and oestrogen profiles. Levels of gonadal androgen and oestrogen were investigated as a function of sex and position in a social hierarchy in free-living individuals of the skunk anemonefish Amphiprion akallopisos, a protandrous pomacentrid fish with a size-based dominance hierarchical social system. Plasma levels of 11-ketotestosterone (11-KT), testosterone (T) and 17β-oestradiol (E 2 ), as well as conversion ratios from T, were measured by ELISA from 111 individuals along a linear hierarchy from 38 social groups in the wild. Blood plasma levels of 11-KT and E 2 showed sex differences, being higher in males and females respectively as expected based on their role as the major androgen and oestrogen in fish reproduction. However, no sex differences were found for T, which may represent its role in territorial defence or simply as a precursor for the synthesis of 11-KT and E 2 . In terms of the hierarchical social system within males, 11-KT levels decline as the hierarchy is descended, which may represent their decreasing reproductive opportunity, as well as the decreasing levels of aggression towards males lower in the hierarchy. In summary, the size-based dominance hierarchy is associated with distinct steroid levels of 11-KT and E 2 between individual free-living A. akallopisos that closely resemble those of species in which breeding individuals suppress reproduction of conspecifics lower in the hierarchy. © 2018 The Fisheries Society of the British Isles.

  13. Mycoplasma salivarium as a dominant coloniser of Fanconi anaemia associated oral carcinoma.

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    Birgit Henrich

    Full Text Available Mycoplasma salivarium belongs to the class of the smallest self-replicating Tenericutes and is predominantly found in the oral cavity of humans. In general it is considered as a non-pathogenic commensal. However, some reports point to an association with human diseases. M. salivarium was found e.g. as causative agent of a submasseteric abscess, in necrotic dental pulp, in brain abscess and clogged biliary stent. Here we describe the detection of M. salivarium on the surface of a squamous cell carcinoma of the tongue of a patient with Fanconi anaemia (FA. FA is an inherited bone marrow failure syndrome based on defective DNA-repair that increases the risk of carcinomas especially oral squamous cell carcinoma. Employing high coverage, massive parallel Roche/454-next-generation-sequencing of 16S rRNA gene amplicons we analysed the oral microbiome of this FA patient in comparison to that of an FA patient with a benign leukoplakia and five healthy individuals. The microbiota of the FA patient with leukoplakia correlated well with that of the healthy controls. A dominance of Streptococcus, Veillonella and Neisseria species was typically observed. In contrast, the microbiome of the cancer bearing FA patient was dominated by Pseudomonas aeruginosa at the healthy sites, which changed to a predominance of 98% M. salivarium on the tumour surface. Quantification of the mycoplasma load in five healthy, two tumour- and two leukoplakia-FA patients by TaqMan-PCR confirmed the prevalence of M. salivarium at the tumour sites. These new findings suggest that this mycoplasma species with its reduced coding capacity found ideal breeding grounds at the tumour sites. Interestingly, the oral cavity of all FA patients and especially samples at the tumour sites were in addition positive for Candida albicans. It remains to be elucidated in further studies whether M. salivarium can be used as a predictive biomarker for tumour development in these patients.

  14. Looking at eye dominance from a different angle: is sighting strength related to hand preference?

    Science.gov (United States)

    Carey, David P; Hutchinson, Claire V

    2013-10-01

    Sighting dominance (the behavioural preference for one eye over the other under monocular viewing conditions) has traditionally been thought of as a robust individual trait. However, Khan and Crawford (2001) have shown that, under certain viewing conditions, eye preference reverses as a function of horizontal gaze angle. Remarkably, the reversal of sighting from one eye to the other depends on which hand is used to reach out and grasp the target. Their procedure provides an ideal way to measure the strength of monocular preference for sighting, which may be related to other indicators of hemispheric specialisation for speech, language and motor function. Therefore, we hypothesised that individuals with consistent side preferences (e.g., right hand, right eye) should have more robust sighting dominance than those with crossed lateral preferences. To test this idea, we compared strength of eye dominance in individuals who are consistently right or left sided for hand and foot preference with those who are not. We also modified their procedure in order to minimise a potential image size confound, suggested by Banks et al. (2004) as an explanation of Khan and Crawford's results. We found that the sighting dominance switch occurred at similar eccentricities when we controlled for effects of hand occlusion and target size differences. We also found that sighting dominance thresholds change predictably with the hand used. However, we found no evidence for relationships between strength of hand preference as assessed by questionnaire or by pegboard performance and strength of sighting dominance. Similarly, participants with consistent hand and foot preferences did not show stronger eye preference as assessed using the Khan and Crawford procedure. These data are discussed in terms of indirect relationships between sighting dominance, hand preference and cerebral specialisation for language and motor control. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Logging impacts on forest structure and seedling dynamics in a Prioria copaifera (Fabaceae) dominated tropical rain forest (Talamanca, Costa Rica).

    Science.gov (United States)

    Valverde-Barrantes, Oscar J; Rocha, Oscar J

    2014-03-01

    The factors that determine the existence of tropical forests dominated by a single species (monodominated forests) have been the subject of debate for a long time. It has been hypothesized that the low frequency of disturbances in monodominated forests and the tolerance to shade of the monodominant species are two important factors explaining the prolonged dominance of a single species. We determined the role of these two factors by examining the effects of logging activities on the floristic composition and seedling dynamics in a Prioria copaifera dominated forest in Southeastern Costa Rica. We determined the floristic composition for trees > or = 2.5cm DBH and the associated recruitment, survival and mortality of tree canopy seedlings in two sites logged two (L-02) and 12 years (L-12) prior to sampling and an unlogged forest (ULF). Our results showed that L-02 stands had lower species richness (25 species) than the L-12 and ULF stands (49 and 46 species, respectively). As expected, we found significant logging effects on the canopy structure of the altered forests, particularly when comparing the L-02 and the ULF stands. Seedling density was higher in ULF (0.96 seedlings/ m2) than in the L-02 and L-12 stands (0.322 and 0.466 seedlings/m2, respectively). However, seedling mortality was higher in the ULF stands (54%) than in the L-02 (26%) and L-12 (15%) stands. P. macroloba in L-02 was the only species with abundant regeneration under P. copaifera in L-02 stand, where it accounted for 35% of the seedlings. Despite the reduction in seedling abundance observed after logging, P. copaifera seems to maintain large seedling populations in these forests, suggesting that this species maintains its dominance after logging disturbances. Our findings challenge the hypothesis that the regeneration of monodominant species is not likely to occur under heavily disturbed canopy conditions.

  16. Logging impacts on forest structure and seedling dynamics in a Prioria copaifera (Fabaceae dominated tropical rain forest (Talamanca, Costa Rica

    Directory of Open Access Journals (Sweden)

    Oscar J. Valverde-Barrantes

    2014-03-01

    Full Text Available The factors that determine the existence of tropical forests dominated by a single species (monodominated forests have been the subject of debate for a long time. It has been hypothesized that the low frequency of disturbances in monodominated forests and the tolerance to shade of the monodominant species are two important factors explaining the prolonged dominance of a single species. We determined the role of these two factors by examining the effects of logging activities on the floristic composition and seedling dynamics in a Prioria copaifera dominated forest in Southeastern Costa Rica. We determined the floristic composition for trees ≥2.5cm DBH and the associated recruitment, survival and mortality of tree canopy seedlings in two sites logged two (L-02 and 12 years (L-12 prior to sampling and an unlogged forest (ULF. Our results showed that L-02 stands had lower species richness (25 species than the L-12 and ULF stands (49 and 46 species, respectively. As expected, we found significant logging effects on the canopy structure of the altered forests, particularly when comparing the L-02 and the ULF stands. Seedling density was higher in ULF (0.96 seedlings/m² than in the L-02and L-12 stands (0.322 and 0.466 seedlings/m², respectively. However, seedling mortality was higher in the ULF stands (54% than in the L-02 (26% and L-12 (15% stands. P. macroloba in L-02 was the only species with abundant regeneration under P. copaifera in L-02 stand, where it accounted for 35% of the seedlings. Despite the reduction in seedling abundance observed after logging, P. copaifera seems to maintain large seedling populations in these forests, suggesting that this species maintains its dominance after logging disturbances. Our findings challenge the hypothesis that the regeneration of monodominant species is not likely to occur under heavily disturbed canopy conditions. Rev. Biol. Trop. 62 (1: 347-357. Epub 2014 March 01.

  17. The effect of the individual species of the N plasma on the characteristics of InAsN quantum dots grown by MBE

    International Nuclear Information System (INIS)

    Gargallo-Caballero, R.; Guzman, A.; Miguel-Sanchez, J.; Hierro, A.; Munoz, E.

    2008-01-01

    The influence of the different species which constitute N plasma, such as atomic nitrogen, diatomic nitrogen and ionized species, on the morphological and optical characteristics of the InAsN quantum dots (QDs) has been studied in this work. We have performed several sets of growths modifying in each one the concentration of these species. Atomic force microscopy (AFM) and photoluminescence (PL) techniques have been used to perform the surface characterization and the optical analysis of these samples, respectively. Clearly, we have found a strong correlation between the structural and optical characteristics of the InAsN QDs with the plasma composition used during the growth. Ionized species favour the high density of QDs, atomic nitrogen increase dimensions of the QDs and molecular nitrogen does not almost affect the characteristics of these nanostructures. An increment of ionized species in the plasma yields a higher density of QDs, an increase in the atomic nitrogen increases the dimensions of the QDs and the molecular nitrogen flux used does not almost affect the characteristics of these nanostructures. Also, we have found that there is not redshift of the peak wavelength of the PL emission as we increase the atomic nitrogen concentration during the growth. This may be due to equal nitrogen incorporation into the quantum dots. We supposed that the mechanism dominating in it is possible that the nitrogen incorporation in these types of nanostructures depend on another growth parameter

  18. Resistance Against Basil Downy Mildew in Ocimum Species.

    Science.gov (United States)

    Ben-Naim, Yariv; Falach, Lidan; Cohen, Yigal

    2015-06-01

    Downy mildew, caused by the oomycete Peronospora belbahrii, is a devastating disease of sweet basil. In this study, 113 accessions of Ocimum species (83 Plant Introduction entries and 30 commercial entries) were tested for resistance against downy mildew at the seedling stage in growth chambers, and during three seasons, in the field. Most entries belonging to O. basilicum were highly susceptible whereas most entries belonging to O. americanum, O. kilimanadascharicum, O. gratissimum, O. campechianum, or O. tenuiflorum were highly resistant at both the seedling stage and the field. Twenty-seven highly resistant individual plants were each crossed with the susceptible sweet basil 'Peri', and the F1 progeny plants were examined for disease resistance. The F1 plants of two crosses were highly resistant, F1 plants of 24 crosses were moderately resistant, and F1 plants of one cross were susceptible, suggesting full, partial, or no dominance of the resistance gene(s), respectively. These data confirm the feasibility of producing downy mildew-resistant cultivars of sweet basil by crossing with wild Ocimum species.

  19. Analysis of diversity of wood-inhabiting fungi retrieved from a Mediterranean forest dominated by Pinus pinaster Aiton

    Directory of Open Access Journals (Sweden)

    Maria D'Aguanno

    2016-04-01

    Full Text Available The present paper is focused on the diversity of wood-inhabiting fungi in a poorly investigated habitat: a Mediterranean forest dominated by maritime pine. The sampling area lies in Tocchi biogenetic Reserve, located in the province of Siena (Tuscany, Italy. The monitoring campaign was carried out in 10 permanents plots, taking note of all the fungal species found on each piece of dead wood, irrespective of size and stage of decay. Over one year of surveys, 56 taxa of wood-inhabiting fungi were recorded, among which 39 are corticoids species, 16 polypores and 1 Heterobasidiomycetes. The fungal community seems to be dominated by a small number of species, which are more abundant than the others. Moreover, there are some specific features of deadwood influencing the species composition, such as the presence of coarse woody debris at the first decay stage and fine woody debris at the late decay stages. The results allowed characterizing the wood-inhabiting fungal community in this forest reserve, broadening our knowledge on several species and providing a preliminary database for further studies in Mediterranean areas.

  20. Urbanization and the more-individuals hypothesis.

    Science.gov (United States)

    Chiari, Claudia; Dinetti, Marco; Licciardello, Cinzia; Licitra, Gaetano; Pautasso, Marco

    2010-03-01

    1. Urbanization is a landscape process affecting biodiversity world-wide. Despite many urban-rural studies of bird assemblages, it is still unclear whether more species-rich communities have more individuals, regardless of the level of urbanization. The more-individuals hypothesis assumes that species-rich communities have larger populations, thus reducing the chance of local extinctions. 2. Using newly collated avian distribution data for 1 km(2) grid cells across Florence, Italy, we show a significantly positive relationship between species richness and assemblage abundance for the whole urban area. This richness-abundance relationship persists for the 1 km(2) grid cells with less than 50% of urbanized territory, as well as for the remaining grid cells, with no significant difference in the slope of the relationship. These results support the more-individuals hypothesis as an explanation of patterns in species richness, also in human modified and fragmented habitats. 3. However, the intercept of the species richness-abundance relationship is significantly lower for highly urbanized grid cells. Our study confirms that urban communities have lower species richness but counters the common notion that assemblages in densely urbanized ecosystems have more individuals. In Florence, highly inhabited areas show fewer species and lower assemblage abundance. 4. Urbanized ecosystems are an ongoing large-scale natural experiment which can be used to test ecological theories empirically.

  1. Considerations regarding the dominance of Cylindrospermopsis raciborskii under low light availability in a low phosphorus lake

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    Denise Tonetta

    2015-09-01

    Full Text Available ABSTRACTAlthough many studies have shown that the dispersion, increased abundance and dominance of cyanobacteria can be attributed to nutrient enrichment, we discuss features contributing to the dominance of Cylindrospermopsis raciborskii in a shallow, polymictic, subtropical coastal lake with low phosphorus and light limitation (Peri Lake. The presence and dominance of C. raciborskii in an environment with such characteristics emphasizes the idea that nutrients alone do not explain the high density of this cyanobacterium. Other features should be considered in explaining this species dominance, such as phosphorus storage and physiological flexibilitywhich seem to be key features to high densities in low phosphorus systems.

  2. Ecomorphology and resource use by dominant species of tropical estuarine juvenile fishes

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    André Luiz Machado Pessanha

    Full Text Available Eleven ecomorphological attributes and diet of seventeen juvenile fish species were examined to test the hypothesis that morphological patterns determine resource uses in estuarine habitats. Species were separated according to the apparatus to food capture and habitat use (benthic or pelagic in three different groups: (1 a group with depressed fish body, strong caudal peduncle and enlarged pectoral fins; (2 a second group laterally flattened with a wide protruding mouth, and (3 a third group strongly flattened with small pectorals fins. The following six trophic groups were organized based on prey categories: Zooplanktivores, Benthivores, Omnivores, Detritivores, Macrocarnivores and Insectivores. Significant results (PERMANOVA between ecomorphological indices and habitat and between ecomorphological indices and trophic groups were found. These data indicate that similarity of ecomorphological forms, which minimize the influence of environment and partitioning of food, would help facilitate the co-existence of these fish when they are abundant in this tropical estuary.

  3. Effect of Conservation on Spatial Pattern of Dominant Trees in Beech (Fagus Orientalis Lipsky Communities, (Case Study: Masal, Guilan

    Directory of Open Access Journals (Sweden)

    S. S. Ebrahimi

    2013-12-01

    Full Text Available Spatial patterns are suitable tools for optimal management in many forested areas. In this research, the effect of conservation on spatial pattern of dominant trees has been studied. To achieving this purpose, protected and non- protected forests were selected in Masal region of Guilan province as the study area. Sampling methods including fixed- area plots and distance methods, such as T- square and compound sampling were used 25 circle sample plots, each with an area 1000 m2and 25 sampling points were taken. Then, tree species in plot samples and the distance of interest were identified and measured. Dispersion indices such as Green, Morisata, standardized Morisata, Hopkins, Eberhart, Johnson and Zimmer, Hines and C were used to analyze the spatial pattern in the areas. All indices related to plot samples indicated the clumped pattern for dominant species in protected and non- protected areas. The results of the distance indices have indicated that destruction changes the spatial pattern of dominant species and these species had different pattern in these areas. Among the distance indices, C and Hines indices revealed differences and they were suitable to describe the spatial pattern of both areas.

  4. Hydrogen sulfide oxidation in novel Horizontal-Flow Biofilm Reactors dominated by an Acidithiobacillus and a Thiobacillus species.

    Science.gov (United States)

    Gerrity, S; Kennelly, C; Clifford, E; Collins, G

    2016-09-01

    Hydrogen Sulfide (H2S) is an odourous, highly toxic gas commonly encountered in various commercial and municipal sectors. Three novel, laboratory-scale, Horizontal-Flow Biofilm Reactors (HFBRs) were tested for the removal of H2S gas from air streams over a 178-day trial at 10°C. Removal rates of up to 15.1 g [H2S] m(-3) h(-1) were achieved, demonstrating the HFBRs as a feasible technology for the treatment of H2S-contaminated airstreams at low temperatures. Bio-oxidation of H2S in the reactors led to the production of H(+) and sulfate (SO(2-)4) ions, resulting in the acidification of the liquid phase. Reduced removal efficiency was observed at loading rates of 15.1 g [H2S] m(-3) h(-1). NaHCO3 addition to the liquid nutrient feed (synthetic wastewater (SWW)) resulted in improved H2S removal. Bacterial diversity, which was investigated by sequencing and fingerprinting 16S rRNA genes, was low, likely due to the harsh conditions prevailing in the systems. The HFBRs were dominated by two species from the genus Acidithiobacillus and Thiobacillus. Nonetheless, there were significant differences in microbial community structure between distinct HFBR zones due to the influence of alkalinity, pH and SO4 concentrations. Despite the low temperature, this study indicates HFBRs have an excellent potential to biologically treat H2S-contaminated airstreams.

  5. Study of the distribution of Malassezia species in patients with pityriasis versicolor and healthy individuals in Tertiary Care Hospital, Punjab

    Directory of Open Access Journals (Sweden)

    M Kaur

    2013-01-01

    Full Text Available Purpose: Pityriasis versicolor (PV is a chronic superficial fungal disease caused by Malassezia species. Our aim was to identify Malassezia species from PV patients and healthy individuals in Punjab. Materials and Methods: Modified Dixon agar was used as isolation culture medium. Identification was based on morphological observation and biochemical evaluation. The biochemical evaluation consisted of culture onto Sabouraud dextrose agar, catalase reaction, Tween assimilation, Cremophor EL assimilation, splitting of esculin and growth at 38 0 C. Results: Out of 58 microscopically diagnosed cases of PV, growth was obtained from 54 (93.10% cases. The most frequently isolated species were M. globosa, M. sympodialis and M. furfur which made up 51.79%, 31.42% and 18.51% of the isolated etiological agents respectively. However, the major isolate from the back of healthy individuals was M. sympodialis (47.61%, followed by M.obtusa (19.04%, M. globosa (14.20%, M. furfur (9.52%, M. pachydermatis (4.76% and M. slooffiae (4.76%. Conclusions: M. globosa in its mycelial phase was the main etiological agent, but as normal flora from the back of healthy subjects, it was found in significantly less number (P = 0.01, suggesting that the higher pathogenicity of M. globosa in terms of enzymatic endowment, might be the cause of its predominance in PV lesions.

  6. Hypothalamic digoxin and hemispheric chemical dominance: relation to alcoholic addiction, alcoholic cirrhosis, and acquired hepatocerebral degeneration.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-08-01

    The isoprenoid pathway produces three key metabolites--endogenous digoxin (modulate tryptophan/tyrosine transport), dolichol (important in N -glycosylation of proteins), and ubiquinone (free radical scavenger). It was considered pertinent to assess the pathway in alcoholic addiction, alcoholic cirrhosis, and acquired hepatocerebral degeneration. Since endogenous digoxin can regulate neurotransmitter transport, the pathway was also assessed in individuals with differing hemispheric dominance to find out the role of hemispheric dominance in its pathogenesis. In the patient group there was elevated digoxin synthesis, increased dolichol and glycoconjugate levels, and low ubiquinone and elevated free radical levels. There was also an increase in tryptophan catabolites and a reduction in tyrosine catabolites as reduced endogenous morphine synthesis from tyrosine. There was an increase in cholesterol:phospholipid ratio and a reduction in glycoconjugate level of RBC membrane in these groups of patients. The same patterns were obtained in individuals with right hemispheric chemical dominance. Alcoholic cirrhosis, alcoholic addiction, and acquired hepatocerebral degeneration are associated with an upregulated isoprenoid pathway and elevated digoxin secretion from the hypothalamus. This can contribute to NMDA excitotoxicity and altered connective tissue/lipid metabolism important in its pathogenesis. Endogenous morphine deficiency plays a role in alcoholic addiction. Alcoholic cirrhosis, addiction, and acquired hepato -cerebral degeneration occur in right hemispheric chemically dominant individuals. Ninety percent of the patients with alcoholic addiction, alcoholic cirrhosis, and acquired hepatocerebral degeneration were right-handed and left hemispheric dominant by the dichotic listening test. However, their biochemical patterns were similar to those obtained in right hemispheric chemical dominance. Hemispheric chemical dominance is a different entity and has no correlation

  7. Genomic definition of species. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Crkvenjakov, R.; Dramanac, R.

    1992-06-01

    A genome is the sum total of the DNA sequences in the cells of an individual organism. The common usage that species possess genomes comes naturally to biochemists, who have shown that all protein and nucleic acid molecules are at the same time species and individual-specific, with minor individual variations being superimposed on a consensus sequence that is constant for a species. By extension, this property is attributed to the common features of DNA in the chromosomes of members of a given species and is called (species) genome. The definition of species based on chromosomes, genes, or genome common to its member organisms has been implied or mentioned in passing numerous times. Some population biologists think that members of species have similar ``homeostatic genotypes,`` which are to a degree resistant to mutation or environmental change in the production of a basic phenotype.

  8. Counselor-Advocate-Scholar Model: Changing the Dominant Discourse in Counseling

    Science.gov (United States)

    Ratts, Manivong J.; Greenleaf, Arie T.

    2018-01-01

    Discourse represents the languages, ideas, and images that together shape one's understanding of the world. In counseling, discourse determines clinical practice. The authors posit that dominant discourse in counseling promotes an intrapsychic status quo that discounts the relationship between individuals and their environment, which often leads…

  9. Size- and food-dependent growth drives patterns of competitive dominance along productivity gradients

    NARCIS (Netherlands)

    Huss, M.; Gårdmark, A.; van Leeuwen, A.; de Roos, A.M.

    2012-01-01

    Patterns of coexistence among competing species exhibiting size- and food-dependent growth remain largely unexplored. Here we studied mechanisms behind coexistence and shifts in competitive dominance in a size-structured fish guild, representing sprat and herring stocks in the Baltic Sea, using a

  10. The dominance behavioral system and manic temperament: Motivation for dominance, self-perceptions of power, and socially dominant behaviors

    OpenAIRE

    Johnson, Sheri L.; Carver, Charles S.

    2012-01-01

    The dominance behavioral system has been conceptualized as a biologically based system comprising motivation to achieve social power and self-perceptions of power. Biological, behavioral, and social correlates of dominance motivation and self-perceived power have been related to a range of psychopathological tendencies. Preliminary evidence suggests that mania and risk for mania (manic temperament) relate to the dominance system.

  11. Predator control promotes invasive dominated ecological states.

    Science.gov (United States)

    Wallach, Arian D; Johnson, Christopher N; Ritchie, Euan G; O'Neill, Adam J

    2010-08-01

    Invasive species are regarded as one of the top five drivers of the global extinction crisis. In response, extreme measures have been applied in an attempt to control or eradicate invasives, with little success overall. We tested the idea that state shifts to invasive dominance are symptomatic of losses in ecosystem resilience, due to the suppression of apex predators. This concept was investigated in Australia where the high rate of mammalian extinctions is largely attributed to the destructive influence of invasive species. Intensive pest control is widely applied across the continent, simultaneously eliminating Australia's apex predator, the dingo (Canis lupus dingo). We show that predator management accounts for shifts between two main ecosystem states. Lethal control fractures dingo social structure and leads to bottom-up driven increases in invasive mesopredators and herbivores. Where control is relaxed, dingoes re-establish top-down regulation of ecosystems, allowing for the recovery of biodiversity and productivity.

  12. Variation in perceptions of physical dominance and trustworthiness predicts individual differences in the effect of relationship context on women's preferences for masculine pitch in men's voices.

    Science.gov (United States)

    Vukovic, Jovana; Jones, Benedict C; Feinberg, David R; Debruine, Lisa M; Smith, Finlay G; Welling, Lisa L M; Little, Anthony C

    2011-02-01

    Several studies have found that women tend to demonstrate stronger preferences for masculine men as short-term partners than as long-term partners, though there is considerable variation among women in the magnitude of this effect. One possible source of this variation is individual differences in the extent to which women perceive masculine men to possess antisocial traits that are less costly in short-term relationships than in long-term relationships. Consistent with this proposal, here we show that the extent to which women report stronger preferences for men with low (i.e., masculine) voice pitch as short-term partners than as long-term partners is associated with the extent to which they attribute physical dominance and low trustworthiness to these masculine voices. Thus, our findings suggest that variation in the extent to which women attribute negative personality characteristics to masculine men predicts individual differences in the magnitude of the effect of relationship context on women's masculinity preferences, highlighting the importance of perceived personality attributions for individual differences in women's judgments of men's vocal attractiveness and, potentially, their mate preferences. ©2010 The British Psychological Society.

  13. Species composition and community structure of subtropical forest stands in western himalayan foothills of kashmir

    International Nuclear Information System (INIS)

    Shaheen, H.; Malik, N. M.; Dar, M. E. U. I.

    2015-01-01

    Lesser Himalayan subtropical forests have unique species composition due to diverse climatic and topographic factors which create numerous microhabitats. Phytosociological characteristics, structural attributes and biological spectrum of plant communities in the forests of Himalayan foothills in Kashmir were analyzed. A total of 65 species belonging to 26 plant families were recorded constituting 6 plant communities. Average value of diversity recorded for the communities was 2.44; species richness 4.01; whereas evenness was found to be 0.48. The species data indicated random distribution of species with a hump shaped diversity pattern directly correlated with increasing altitude. Themeda anathera was the dominant species with an importance value percentage of 14.7 percentage followed by Pinus roxburghii (9.6 percentage), Mallotus philippenensis (5.2 percentage), Malvastrum coromandelianum (5.1 percentage), Acacia modesta (5 percentage), Olea ferruginea (3.8 percentage) and Oxalis corniculata (3.2 percentage). Vegetation was dominated by Therophytes (30 percentage) and megaphanerophytes (23.3) with dominant leaf spectrum as leptophylls (31.6 percentage). Thirty seven percent plants had medicinal values followed by 31 percentage having fodder values where as 12 percentage used as fuel. Principal component analyses and cluster analyses revealed the association of dominant species with specific sites due to prevailing environmental conditions. The distribution of species in ordination diagrams indicated a continuous change in species composition along the altitudinal gradient. Key stone tree species were subject to immense tree felling resulting in deteriorating changes in forest structure. Visual indicators showed over grazing at all the studied sites evident from the dominance of unpalatable species. Local forest stands demand immediate attention of policy makers as well as forest management so that local diversity and floristic richness could be conserved and

  14. Gender and facial dominance in gaze cuing: emotional context matters in the eyes that we follow.

    Directory of Open Access Journals (Sweden)

    Garian Ohlsen

    Full Text Available Gaze following is a socio-cognitive process that provides adaptive information about potential threats and opportunities in the individual's environment. The aim of the present study was to investigate the potential interaction between emotional context and facial dominance in gaze following. We used the gaze cue task to induce attention to or away from the location of a target stimulus. In the experiment, the gaze cue either belonged to a (dominant looking male face or a (non-dominant looking female face. Critically, prior to the task, individuals were primed with pictures of threat or no threat to induce either a dangerous or safe environment. Findings revealed that the primed emotional context critically influenced the gaze cuing effect. While a gaze cue of the dominant male face influenced performance in both the threat and no-threat conditions, the gaze cue of the non-dominant female face only influenced performance in the no-threat condition. This research suggests an implicit, context-dependent follower bias, which carries implications for research on visual attention, social cognition, and leadership.

  15. Fish and phytoplankton exhibit contrasting temporal species abundance patterns in a dynamic north temperate lake.

    Directory of Open Access Journals (Sweden)

    Gretchen J A Hansen

    Full Text Available Temporal patterns of species abundance, although less well-studied than spatial patterns, provide valuable insight to the processes governing community assembly. We compared temporal abundance distributions of two communities, phytoplankton and fish, in a north temperate lake. We used both 17 years of observed relative abundance data as well as resampled data from Monte Carlo simulations to account for the possible effects of non-detection of rare species. Similar to what has been found in other communities, phytoplankton and fish species that appeared more frequently were generally more abundant than rare species. However, neither community exhibited two distinct groups of "core" (common occurrence and high abundance and "occasional" (rare occurrence and low abundance species. Both observed and resampled data show that the phytoplankton community was dominated by occasional species appearing in only one year that exhibited large variation in their abundances, while the fish community was dominated by core species occurring in all 17 years at high abundances. We hypothesize that the life-history traits that enable phytoplankton to persist in highly dynamic environments may result in communities dominated by occasional species capable of reaching high abundances when conditions allow. Conversely, longer turnover times and broad environmental tolerances of fish may result in communities dominated by core species structured primarily by competitive interactions.

  16. Fish and Phytoplankton Exhibit Contrasting Temporal Species Abundance Patterns in a Dynamic North Temperate Lake

    Science.gov (United States)

    Hansen, Gretchen J. A.; Carey, Cayelan C.

    2015-01-01

    Temporal patterns of species abundance, although less well-studied than spatial patterns, provide valuable insight to the processes governing community assembly. We compared temporal abundance distributions of two communities, phytoplankton and fish, in a north temperate lake. We used both 17 years of observed relative abundance data as well as resampled data from Monte Carlo simulations to account for the possible effects of non-detection of rare species. Similar to what has been found in other communities, phytoplankton and fish species that appeared more frequently were generally more abundant than rare species. However, neither community exhibited two distinct groups of “core” (common occurrence and high abundance) and “occasional” (rare occurrence and low abundance) species. Both observed and resampled data show that the phytoplankton community was dominated by occasional species appearing in only one year that exhibited large variation in their abundances, while the fish community was dominated by core species occurring in all 17 years at high abundances. We hypothesize that the life-history traits that enable phytoplankton to persist in highly dynamic environments may result in communities dominated by occasional species capable of reaching high abundances when conditions allow. Conversely, longer turnover times and broad environmental tolerances of fish may result in communities dominated by core species structured primarily by competitive interactions. PMID:25651399

  17. A New Algorithm Using the Non-Dominated Tree to Improve Non-Dominated Sorting.

    Science.gov (United States)

    Gustavsson, Patrik; Syberfeldt, Anna

    2018-01-01

    Non-dominated sorting is a technique often used in evolutionary algorithms to determine the quality of solutions in a population. The most common algorithm is the Fast Non-dominated Sort (FNS). This algorithm, however, has the drawback that its performance deteriorates when the population size grows. The same drawback applies also to other non-dominating sorting algorithms such as the Efficient Non-dominated Sort with Binary Strategy (ENS-BS). An algorithm suggested to overcome this drawback is the Divide-and-Conquer Non-dominated Sort (DCNS) which works well on a limited number of objectives but deteriorates when the number of objectives grows. This article presents a new, more efficient algorithm called the Efficient Non-dominated Sort with Non-Dominated Tree (ENS-NDT). ENS-NDT is an extension of the ENS-BS algorithm and uses a novel Non-Dominated Tree (NDTree) to speed up the non-dominated sorting. ENS-NDT is able to handle large population sizes and a large number of objectives more efficiently than existing algorithms for non-dominated sorting. In the article, it is shown that with ENS-NDT the runtime of multi-objective optimization algorithms such as the Non-Dominated Sorting Genetic Algorithm II (NSGA-II) can be substantially reduced.

  18. The Fragility of Individual-Based Explanations of Social Hierarchies: A Test Using Animal Pecking Orders

    Science.gov (United States)

    2016-01-01

    The standard approach in accounting for hierarchical differentiation in biology and the social sciences considers a hierarchy as a static distribution of individuals possessing differing amounts of some valued commodity, assumes that the hierarchy is generated by micro-level processes involving individuals, and attempts to reverse engineer the processes that produced the hierarchy. However, sufficient experimental and analytical results are available to evaluate this standard approach in the case of animal dominance hierarchies (pecking orders). Our evaluation using evidence from hierarchy formation in small groups of both hens and cichlid fish reveals significant deficiencies in the three tenets of the standard approach in accounting for the organization of dominance hierarchies. In consequence, we suggest that a new approach is needed to explain the organization of pecking orders and, very possibly, by implication, for other kinds of social hierarchies. We develop an example of such an approach that considers dominance hierarchies to be dynamic networks, uses dynamic sequences of interaction (dynamic network motifs) to explain the organization of dominance hierarchies, and derives these dynamic sequences directly from observation of hierarchy formation. We test this dynamical explanation using computer simulation and find a good fit with actual dynamics of hierarchy formation in small groups of hens. We hypothesize that the same dynamic sequences are used in small groups of many other animal species forming pecking orders, and we discuss the data required to evaluate our hypothesis. Finally, we briefly consider how our dynamic approach may be generalized to other kinds of social hierarchies using the example of the distribution of empty gastropod (snail) shells occupied in populations of hermit crabs. PMID:27410230

  19. Effects of Different Social and Environmental Conditions on Established Dominance Relationships in Crayfish.

    Science.gov (United States)

    Herberholz, Jens; Swierzbinski, Matthew E; Birke, Juliane M

    2016-04-01

    Like most social animals, crayfish readily form dominance relationships and linear social hierarchies when competing for limited resources. Competition often entails dyadic aggressive interactions, from which one animal emerges as the dominant and one as the subordinate. Once dominance relationships are formed, they typically remain stable for extended periods of time; thus, access to future resources is divided unequally among conspecifics. We previously showed that firmly established dominance relationships in juvenile crayfish can be disrupted by briefly adding a larger conspecific to the original pair. This finding suggested that the stability of social relationships in crayfish was highly context-dependent and more transient than previously assumed. We now report results that further identify the mechanisms underlying the destabilization of crayfish dominance relationships. We found that rank orders remained stable when conspecifics of smaller or equal size were added to the original pair, suggesting that both dominant and subordinate must be defeated by a larger crayfish in order to destabilize dominance relationships. We also found that dominance relationships remained stable when both members of the original pair were defeated by larger conspecifics in the absence of their original opponent. This showed that dominance relationships are not destabilized unless both animals experience defeat together. Lastly, we found that dominance relationships of pairs were successfully disrupted by larger intruders, although with reduced magnitude, after all chemical cues associated with earlier agonistic experiences were eliminated. These findings provide important new insights into the contextual features that regulate the stability of social dominance relationships in crayfish and probably in other species as well. © 2016 Marine Biological Laboratory.

  20. Species-specific separation of lake plankton reveals divergent food assimilation patterns in rotifers.

    Science.gov (United States)

    Burian, Alfred; Kainz, Martin J; Schagerl, Michael; Yasindi, Andrew

    2014-06-01

    1. The analysis of functional groups with a resolution to the individual species level is a basic requirement to better understand complex interactions in aquatic food webs. Species-specific stable isotope analyses are currently applied to analyse the trophic role of large zooplankton or fish species, but technical constraints complicate their application to smaller-sized plankton. 2. We investigated rotifer food assimilation during a short-term microzooplankton bloom in the East African soda lake Nakuru by developing a method for species-specific sampling of rotifers. 3. The two dominant rotifers, Brachionus plicatilis and Brachionus dimidiatus , were separated to single-species samples (purity >95%) and significantly differed in their isotopic values (4.1‰ in δ 13 C and 1.5‰ in δ 15 N). Bayesian mixing models indicated that isotopic differences were caused by different assimilation of filamentous cyanobacteria and particles plicatilis (48%), whereas it was hardly ingested by B. dimidiatus . Overall, A . fusiformis was, relative to its biomass, assimilated to small extents, demonstrating a high grazing resistance of this species. 5. In combination with high population densities, these results demonstrate a strong potential of rotifer blooms to shape phytoplankton communities and are the first in situ demonstration of a quantitatively important direct trophic link between rotifers and filamentous cyanobacteria.

  1. Boldness traits, not dominance, predict exploratory flight range and homing behaviour in homing pigeons.

    Science.gov (United States)

    Portugal, Steven J; Ricketts, Rhianna L; Chappell, Jackie; White, Craig R; Shepard, Emily L; Biro, Dora

    2017-08-19

    Group living has been proposed to yield benefits that enhance fitness above the level that would be achieved through living as solitary individuals. Dominance hierarchies occur commonly in these social assemblages, and result, by definition, in resources not being evenly distributed between group members. Determinants of rank within a dominance hierarchy can be associated with morphological characteristics, previous experience of the individual, or personality traits such as exploration tendencies. The purpose of this study was to investigate whether greater exploration and positive responses to novel objects in homing pigeons ( Columba livia ) measured under laboratory conditions were associated with (i) greater initial exploration of the local area around the home loft during spontaneous exploration flights (SEF), (ii) faster and more efficient homing flights when released from further afield, and (iii) whether the traits of greater exploration and more positive responses to novel objects were more likely to be exhibited by the more dominant individuals within the group. There was no relationship between laboratory-based novel object exploration and position within the dominance hierarchy. Pigeons that were neophobic under laboratory conditions did not explore the local area during SEF opportunities. When released from sites further from home, neophobic pigeons took longer routes to home compared to those birds that had not exhibited neophobic traits under laboratory conditions, and had spontaneously explored to a greater extent. The lack of exploration in the neophobic birds is likely to have resulted in the increased costs of homing following release: unfamiliarity with the landscape likely led to the greater distances travelled and less efficient routes taken. Birds that demonstrated a lack of neophobia were not the dominant individuals inside the loft, and thus would have less access to resources such as food and potentially mates. However, a lack of

  2. Elucidating dominant pathways of the nano-particle self-assembly process.

    Science.gov (United States)

    Zeng, Xiangze; Li, Bin; Qiao, Qin; Zhu, Lizhe; Lu, Zhong-Yuan; Huang, Xuhui

    2016-09-14

    Self-assembly processes play a key role in the fabrication of functional nano-structures with widespread application in drug delivery and micro-reactors. In addition to the thermodynamics, the kinetics of the self-assembled nano-structures also play an important role in determining the formed structures. However, as the self-assembly process is often highly heterogeneous, systematic elucidation of the dominant kinetic pathways of self-assembly is challenging. Here, based on mass flow, we developed a new method for the construction of kinetic network models and applied it to identify the dominant kinetic pathways for the self-assembly of star-like block copolymers. We found that the dominant pathways are controlled by two competing kinetic parameters: the encounter time Te, characterizing the frequency of collision and the transition time Tt for the aggregate morphology change from rod to sphere. Interestingly, two distinct self-assembly mechanisms, diffusion of an individual copolymer into the aggregate core and membrane closure, both appear at different stages (with different values of Tt) of a single self-assembly process. In particular, the diffusion mechanism dominates the middle-sized semi-vesicle formation stage (with large Tt), while the membrane closure mechanism dominates the large-sized vesicle formation stage (with small Tt). Through the rational design of the hydrophibicity of the copolymer, we successfully tuned the transition time Tt and altered the dominant self-assembly pathways.

  3. Unrecognized coral species diversity masks differences in functional ecology.

    Science.gov (United States)

    Boulay, Jennifer N; Hellberg, Michael E; Cortés, Jorge; Baums, Iliana B

    2014-02-07

    Porites corals are foundation species on Pacific reefs but a confused taxonomy hinders understanding of their ecosystem function and responses to climate change. Here, we show that what has been considered a single species in the eastern tropical Pacific, Porites lobata, includes a morphologically similar yet ecologically distinct species, Porites evermanni. While P. lobata reproduces mainly sexually, P. evermanni dominates in areas where triggerfish prey on bioeroding mussels living within the coral skeleton, thereby generating asexual coral fragments. These fragments proliferate in marginal habitat not colonized by P. lobata. The two Porites species also show a differential bleaching response despite hosting the same dominant symbiont subclade. Thus, hidden diversity within these reef-builders has until now obscured differences in trophic interactions, reproductive dynamics and bleaching susceptibility, indicative of differential responses when confronted with future climate change.

  4. Shape of the orbital opening: individual characterization and analysis of variability in modern humans, Gorilla gorilla, and Pan troglodytes.

    Science.gov (United States)

    Schmittbuhl, M; Le Minor, J M; Allenbach, B; Schaaf, A

    1999-05-01

    The description of the human orbital shape is principally qualitative in the classical literature, and characterised by adjectives such as circular, rectangular or quadrangular. In order to provide a precise quantification and interpretation of this shape, a study based on automatic image analysis and Fourier analysis was carried out on 45 human skulls (30 males, 15 females), and for comparison on 61 skulls of Gorilla gorilla (40 males, 21 females), and 34 skulls of Pan troglodytes (20 males, 14 females). Sexual dimorphism in the shape of the orbital opening was not demonstrated. Its dominant morphological features could be characterized by Fourier analysis; elliptical elongation and quadrangularity were dominant morphological features of the shape of the orbital opening in the three species. Elliptical elongation was more marked in humans and Pan, whereas quadrangularity was particularly emphasized in Gorilla. An intraspecific variability of the shape of the orbital opening existed in humans, Gorilla and Pan, and seemed close in the three species. Interspecific partition between humans, Gorilla and Pan was demonstrated despite the variability observed in the three species studied. Interspecific differences between Gorilla and the Pan-humans group were principally explained by the differences in quadrangularity, and by differences in orientation of triangularity and pentagonality. Differences in the shape of the orbital opening between humans and Pan were principally explained by differences in hexagonality, and by differences in orientation of quadrangularity. A closeness of shape between some humans and some individuals in Pan and, to a lesser degree, with some individuals in Gorilla was observed, demonstrating the existence of a morphological continuum of the shape of the orbital opening in hominoids.

  5. Species rarity: definition, causes, and classification

    Science.gov (United States)

    Curtis H. Flather; Carolyn Hull Sieg

    2007-01-01

    In virtually all ecological communities around the world, most species are represented by few individuals, and most individuals come from only a few of the most common species. Why this distribution of species abundances is so regularly observed among different taxonomic sets in geographically diverse systems is a question that has received considerable theoretical and...

  6. Invasive plant species in hardwood tree plantations

    Science.gov (United States)

    Rochelle R. Beasley; Paula M. Pijut

    2010-01-01

    Invasive plants are species that can grow and spread aggressively, mature quickly, and invade an ecosystem causing economic and environmental damage. Invasive plants usually invade disturbed areas, but can also colonize small areas quickly, and may spread and dominate large areas in a few short years. Invasive plant species displace native or desirable forest...

  7. Genomic Analysis and Surveillance of the Coronavirus Dominant in Ducks in China.

    Directory of Open Access Journals (Sweden)

    Qing-Ye Zhuang

    Full Text Available The genetic diversity, evolution, distribution, and taxonomy of some coronaviruses dominant in birds other than chickens remain enigmatic. In this study we sequenced the genome of a newly identified coronavirus dominant in ducks (DdCoV, and performed a large-scale surveillance of coronaviruses in chickens and ducks using a conserved RT-PCR assay. The viral genome harbors a tandem repeat which is rare in vertebrate RNA viruses. The repeat is homologous to some proteins of various cellular organisms, but its origin remains unknown. Many substitutions, insertions, deletions, and some frameshifts and recombination events have occurred in the genome of the DdCoV, as compared with the coronavirus dominant in chickens (CdCoV. The distances between DdCoV and CdCoV are large enough to separate them into different species within the genus Gammacoronavirus. Our surveillance demonstrated that DdCoVs and CdCoVs belong to different lineages and occupy different ecological niches, further supporting that they should be classified into different species. Our surveillance also demonstrated that DdCoVs and CdCoVs are prevalent in live poultry markets in some regions of China. In conclusion, this study shed novel insight into the genetic diversity, evolution, distribution, and taxonomy of the coronaviruses circulating in chickens and ducks.

  8. [Ecological risk assessment of dam construction for terrestrial plant species in middle reach of Lancangjiang River, Southwest China].

    Science.gov (United States)

    Li, Xiao-Yan; Dong, Shi-Kui; Liu, Shi-Liang; Peng, Ming-Chun; Li, Jin-Peng; Zhao, Qing-He; Zhang, Zhao-Ling

    2012-08-01

    Taking the surrounding areas of Xiaowan Reservoir in the middle reach of Lancangjiang River as study area, and based on the vegetation investigation at three sites including electricity transmission area (site 1), electricity-transfer substation and roadsides to the substation (site 2), and emigration area (site 3) in 1997 (before dam construction), another investigation was conducted on the vegetation composition, plant coverage, and dominant species at the same sites in 2010 (after dam construction), aimed to evaluate the ecological risk of the dam construction for the terrestrial plant species in middle reach of Lancangjiang River. There was an obvious difference in the summed dominance ratio of dominant species at the three sites before and after the dam construction. According the types of species (dominant and non-dominant species) and the changes of plant dominance, the ecological risk (ER) for the plant species was categorized into 0 to IV, i.e., no or extremely low ecological risk (0), low ecological risk (I), medium ecological risk (II), high ecological risk (III), and extremely high ecological risk (IV). As affected by the dam construction, the majority of the species were at ER III, and a few species were at ER IV. The percentage of the plant species at ER III and ER IV at site 3 was higher than that at sites 1 and 2. The decrease or loss of native plants and the increase of alien or invasive plants were the major ecological risks caused by the dam construction. Effective protection strategies should be adopted to mitigate the ecological risk of the dam construction for the terrestrial plants at species level.

  9. Community composition of root-associated fungi in a Quercus-dominated temperate forest: “codominance” of mycorrhizal and root-endophytic fungi

    Science.gov (United States)

    Toju, Hirokazu; Yamamoto, Satoshi; Sato, Hirotoshi; Tanabe, Akifumi S; Gilbert, Gregory S; Kadowaki, Kohmei

    2013-01-01

    In terrestrial ecosystems, plant roots are colonized by various clades of mycorrhizal and endophytic fungi. Focused on the root systems of an oak-dominated temperate forest in Japan, we used 454 pyrosequencing to explore how phylogenetically diverse fungi constitute an ecological community of multiple ecotypes. In total, 345 operational taxonomic units (OTUs) of fungi were found from 159 terminal-root samples from 12 plant species occurring in the forest. Due to the dominance of an oak species (Quercus serrata), diverse ectomycorrhizal clades such as Russula, Lactarius, Cortinarius, Tomentella, Amanita, Boletus, and Cenococcum were observed. Unexpectedly, the root-associated fungal community was dominated by root-endophytic ascomycetes in Helotiales, Chaetothyriales, and Rhytismatales. Overall, 55.3% of root samples were colonized by both the commonly observed ascomycetes and ectomycorrhizal fungi; 75.0% of the root samples of the dominant Q. serrata were so cocolonized. Overall, this study revealed that root-associated fungal communities of oak-dominated temperate forests were dominated not only by ectomycorrhizal fungi but also by diverse root endophytes and that potential ecological interactions between the two ecotypes may be important to understand the complex assembly processes of belowground fungal communities. PMID:23762515

  10. Electrically excited hot-electron dominated fluorescent emitters using individual Ga-doped ZnO microwires via metal quasiparticle film decoration.

    Science.gov (United States)

    Liu, Yang; Jiang, Mingming; Zhang, Zhenzhong; Li, Binghui; Zhao, Haifeng; Shan, Chongxin; Shen, Dezhen

    2018-03-28

    The generation of hot electrons from metal nanostructures through plasmon decay provided a direct interfacial charge transfer mechanism, which no longer suffers from the barrier height restrictions observed for metal/semiconductor interfaces. Metal plasmon-mediated energy conversion with higher efficiency has been proposed as a promising alternative to construct novel optoelectronic devices, such as photodetectors, photovoltaic and photocatalytic devices, etc. However, the realization of the electrically-driven generation of hot electrons, and the application in light-emitting devices remain big challenges. Here, hybrid architectures comprising individual Ga-doped ZnO (ZnO:Ga) microwires via metal quasiparticle film decoration were fabricated. The hottest spots could be formed towards the center of the wires, and the quasiparticle films were converted into physically isolated nanoparticles by applying a bias onto the wires. Thus, the hot electrons became spatially localized towards the hottest regions, leading to a release of energy in the form of emitting photons. By adjusting the sputtering times and appropriate alloys, such as Au and Ag, wavelength-tunable emissions could be achieved. To exploit the EL emission characteristics, metal plasmons could be used as active elements to mediate the generation of hot electrons from metal nanostructures, which are located in the light-emitting regions, followed by injection into ZnO:Ga microwire-channels; thus, the production of plasmon decay-induced hot-electrons could function as an efficient approach to dominate emission wavelengths. Therefore, by introducing metal nanostructure decoration, individual ZnO:Ga microwires can be used to construct wavelength-tunable fluorescent emitters. The hybrid architectures of metal-ZnO micro/nanostructures offer a fantastic candidate to broaden the potential applications of semiconducting optoelectronic devices, such as photovoltaic devices, photodetectors, optoelectronic sensors, etc.

  11. Tree competition and species coexistence in a Quercus--Betula forest in the Dongling Mountains in northern China

    Science.gov (United States)

    Hou, Ji-hua; Mi, Xiang-cheng; Liu, Can-ran; Ma, Ke-ping

    2006-09-01

    The population size structure, growth dynamics and mode of competition among adult trees (≥ 4 cm DBH) of six abundant tree species in a 5 ha study plot of a temperate deciduous forest in the Dongling Mountains in northern China were investigated using diffusion and growth dynamics models. In the year of 2000, two dominant species, Quercus liaotungensis and Betula dahurica accounted for ca. 68.69% of the total basal area and 52.71% of the total density of adult plants. Q. liaotungensis, Populus davidiana and Acer mono exhibited inverse J-shaped DBH distributions whereas Betula dahurica, B. platyphylla and Salix caprea had unimodal DBH distributions. One-sided interspecific competition was detected between some species combinations at the scale of the 5 ha study plot, and the competitive effect was mainly size-dependent rather than from species-specific interactions with large individuals in the canopy layer out competing smaller individuals in the understory. Symmetric competition was found between Q. liaotungensis and A. mono only. However, considering the straight line relationship of G ( t, x) - √{D(t, x)}, which suggests that competitive asymmetry is very low or absent, combined with the relatively low mortality of trees with a DBH larger than 4 cm, we speculate that asymmetric interspecific competition was not important in structuring this tree community. Regeneration characteristics of each species are most likely important in regulating species coexistence and stand dynamics in this forest.

  12. Wood-inhabiting, polyporoid fungi in aspen-dominated forests managed for biomass in the U.S. Lake States

    Science.gov (United States)

    Nicholas J. Brazee; Daniel L. Lindner; Shawn Fraver; Anthony W. D' Amato; Amy M. Milo

    2012-01-01

    To better understand the potential long-term effects of biomass harvesting on biodiversity, the polyporoid fungi community was characterized from 120 plots in four aspen-dominated forests in Minnesota. Four deadwood variables (substratum species, substratum type, decay class and diameter class) were recorded for each polyporoid species occurrence. A total of 2358...

  13. Genomic definition of species. Revision 2

    Energy Technology Data Exchange (ETDEWEB)

    Crkvenjakov, R.; Drmanac, R.

    1993-03-01

    A genome is the sum total of the DNA sequences in the cells of an individual organism. The common usage that species possess genomes comes naturally to biochemists, who have shown that all protein and nucleic acid molecules are at the same time species- and individual-specific, with minor individual variations being superimposed on a consensus sequence that is constant for a species. By extension, this property is attributed to the common features of DNA in the chromosomes of members of a given species and is called species genome. Our proposal for the definition of a biological species is as follows: A species comprises a group of actual and potential biological organisms built according to a unique genome program that is recorded, and at least in part expressed, in the structures of their genomic nucleic acid molecule(s), having intragroup sequence differences which can be fully interconverted in the process of organismal reproduction.

  14. A model to assess the emission of individual isoprenoids emitted from Italian ecosystems

    Science.gov (United States)

    Kemper Pacheco, C. J.; Fares, S.; Loreto, F.; Ciccioli, P.

    2012-04-01

    introduced to account for the amount of monoterpene biomass from the litter of stands composed by plants equipped with storage organs. Daily data of incident PAR and leaf temperature obtained from high resolved satellite observation were provided by the partners of the CARBOITALY Project. They were available for the entire year 2006. They were disaggregated into proper day-night cycles. Emission values predicted by the model are in perfect agreement with those that were measured by different micrometeorological techniques in Castelporzioano (Ciccioli et al, J Chromatogr., 2003) and in the Collelongo site (Ciccioli et al. unpublished). The good correlation between modeled and measured values emphasizes the fact that accurate predictions can be obtained if validated emission factors for individual VOC are used in the model. The almost equivalent potential emission of isoprene and monoterpenes reported in a previous work was confirmed, although lower values of total biogenic emissions were found for both classes of hydrocarbons. Data from individual monoterpenes indicates also that highly reactive cis- and b-ocimenes are also quite abundant in many Italian forest ecosystems, including those dominated by coniferous trees, such as Pinus pinaster and sylvestris. This may lead to rather low dominance of pinene generated particles in the air. The high spatial and temporal resolution, combined with the species-specific emission output makes our model particularly suitable for ozono and SOA prediction with both Eulerian and Lagrangian photochemical models, at the scale at which ozono pollution develops in Italy.

  15. Management of Peatland Shrub- and Forest-Dominated Communities for Threatened and Endangered Species

    National Research Council Canada - National Science Library

    Robertson, Kevin

    1998-01-01

    ... or agricultural uses, and they support several threatened, endangered, and sensitive species (TES). Several of these plant communities are rare due to alterations in fire and hydrology over large expanses of the region...

  16. Use of DNA from bite marks can determine species and individual animals that attack humans

    Science.gov (United States)

    Farley, Sean; Talbot, Sandra L.; Sage, George K.; Sinnott, Rick; Coltrane, Jessica

    2014-01-01

    During the summer of 2008, 6 documented attacks and close encounters with brown bears (Ursus arctos) occurred in the greater Anchorage, Alaska (USA) area. We discuss findings from 2 incidents in which people were mauled within 2 km of each other over a 6-week period and in which it was assumed that a single animal was responsible. To ensure public safety, authorities killed a brown bear implicated in the attacks by circumstantial evidence, though it was not known a priori that the animal was responsible. We extracted DNA from hairs and bite sites on the clothing of both victims and determined species and individual identity of the animal(s) involved in both incidents. Genetic data indicated the brown bear killed by authorities was responsible for one of the maulings, but not both. This research demonstrates that DNA-based techniques, with appropriate sampling, can provide unambiguous identification of animals involved in attacks, as well as provide reasonable justification for excluding others. Because DNA-based techniques can unequivocally identify individual bears carrying out attacks, they should be considered a standard method employed in wildlife attack investigations.

  17. Dominant and marginalized discourses in interracial couples' narratives: implications for family therapists.

    Science.gov (United States)

    Killian, Kyle D

    2002-01-01

    This study explores inter-racial couples' family histories, their experiences of their life together, and the dominant and subordinate discourses employed in negotiating racial and ethnic differences. Ten black-white couples were interviewed individually and conjointly. Dominant discourses that emerged from the couples' narratives included those of homogamy, hypersensitivity of persons of color, and the insignificance of familial and societal history. Interracial partners also simultaneously subverted these prevailing ideologies by voicing experience associated with life at the margins of the society. Dominant and subordinate dicourses used by therapists and interracial couples in the therapy room are examined to integrate marginalized "truths" crucial to effective work with interracial couples and persons of color.

  18. The functional biogeography of species

    DEFF Research Database (Denmark)

    Carstensen, Daniel W.; Dalsgaard, Bo; Svenning, Jens-Christian

    2013-01-01

    Biogeographical systems can be analyzed as networks of species and geographical units. Within such a biogeographical network, individual species may differ fundamentally in their linkage pattern, and therefore hold different topological roles. To advance our understanding of the relationship betw...... to distributions at the local community level. We finally discuss how our biogeographical species roles may correspond to the stages of the taxon cycle and other prominent theories of species assembly.......Biogeographical systems can be analyzed as networks of species and geographical units. Within such a biogeographical network, individual species may differ fundamentally in their linkage pattern, and therefore hold different topological roles. To advance our understanding of the relationship...... between species traits and large-scale species distribution patterns in archipelagos, we use a network approach to classify birds as one of four biogeographical species roles: peripherals, connectors, module hubs, and network hubs. These roles are based upon the position of species within the modular...

  19. Soil Seed Bank Dynamics in Tithonia diversifolia Dominated Fallowland Vegetation in Ile-Ife Area of Southwestern Nigeria

    Directory of Open Access Journals (Sweden)

    Samson Olajide OKE

    2009-12-01

    Full Text Available The soil seedbank of Tithonia diversifolia, an invasive species which dominates open waste fallowland vegetation was studied. Two different roadside sites which vary in extent of open waste land were selected.The species composition of the established vegetation was assessed in the two diferent sites. Twenty top soil samples were collected at five different distances (15 cm, 30 cm, 45 cm, 60 cm, and 75 cm inwards away from each main road in dry and rainy seasons and the seed bank composition was determined by greenhouse germination over a 6 month period. The similarity between the composition of the seed bank flora and that of the established vegetation was low. The least and the highest emerged seedlings density was recorded in the 15 metres and 75 metres respectively inwards away from the main road in both seasons. The results of the seedlings emergence is a reflection of the extent of open waste land dominated by the invasive species due to human disturbance (road construction on both sites. Overall results suggest that the emergence of the species from the soil seed bank may be due to the impact of the invasive species Tithonia diversifolia on other plant species in the study environment.

  20. Autosomal dominant syndrome resembling Coffin-Siris syndrome.

    Science.gov (United States)

    Flynn, Maureen A; Milunsky, Jeff M

    2006-06-15

    Coffin-Siris syndrome is a multiple congenital anomaly/mental retardation syndrome with phenotypic variability [OMIM 135900]. The diagnosis is based solely on clinical findings, as there is currently no molecular, biochemical, or cytogenetic analysis available to confirm a diagnosis. Although typically described as an autosomal recessive disorder, autosomal dominant inheritance has also been infrequently reported. We describe a mother and her two daughters who all have features that resemble Coffin-Siris syndrome. However, this is not a completely convincing diagnosis given that hypertelorism is not a feature of Coffin-Siris syndrome and the family is relatively mildly affected. Yet, this family provides further evidence of an autosomal dominant mode of inheritance for a likely variant of Coffin-Siris syndrome (at least in some families). In addition, Sibling 1 had premature thelarche. She is the second reported individual within the spectrum of Coffin-Siris syndrome to have premature thelarche, indicating that it may be a rare clinical feature. Copyright 2006 Wiley-Liss, Inc.

  1. Psychrophile spoilers dominate the bacterial microbiome in musculature samples of slaughter pigs.

    Science.gov (United States)

    Mann, Evelyne; Wetzels, Stefanie U; Pinior, Beate; Metzler-Zebeli, Barbara U; Wagner, Martin; Schmitz-Esser, Stephan

    2016-07-01

    The aim of this study was to disentangle the microbial diversity on porcine musculature. The hypervariable V1-V2 region of the 16S rRNA gene was amplified from DNA samples of clinically healthy slaughter pigs (n=8). Pyrosequencing yielded 37,000 quality-controlled reads and a diverse microbiome with 54-159 OTUs per sample was detected. Interestingly, 6 out of 8 samples were strongly dominated by 1-2 highly abundant OTUs (best hits of highly abundant OTUs: Serratia proteamaculans, Pseudomonas syringae, Aeromonas allosaccharophila, Brochothrix thermosphacta, Acidiphilium cryptum and Escherichia coli). In 1g musculature scraping, 3.20E+06 16S rRNA gene copies and 4.45E+01 Enterobacteriaceae rRNA gene copies were detected with qPCR. We conclude that i.) next-generation sequencing technologies help encompass the full content of complex, bacterial contamination, ii.) psychrophile spoilers dominated the microbiota and iii.) E. coli is an effective marker species for pork contamination, as it was one of very few abundant species being present in all samples. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Identification of Lactobacillus species isolated from traditional cheeses of west Azerbaijan

    Directory of Open Access Journals (Sweden)

    Ali Ehsani

    2014-06-01

    Results: In present study, from a total of 118 isolates of lactobacilli were determined. Lactobacillus plantarum (24%, Lactobacillus casei (20% and Lactobacillus agillis (18% from facultative heterofermentative Lactobacilli and Lactobacillus delbrueckii (21%, Lactobacillus helveticus (14% and Lactobacillus salvariu s (3% from obligative homofermentative Lactobacilli were found to be more dominant species.Conclusions: So for achievement to organoleptic characteristics of traditional cheeses in industrial productions, mixed starters including dominant Lactobacillus species identified in cheeses can be employed.

  3. Interracial prison contact: the pros for (socially dominant) cons.

    Science.gov (United States)

    Hodson, Gordon

    2008-06-01

    Individuals high in social dominance orientation (SDO; Sidanius & Pratto, 1999) endorse group hierarchies and social inequality. Surprisingly little research has addressed contextual factors associated with reduced intergroup biases among such individuals. The present investigation considers a Person x Situation approach to this question in two British prisons, exploring the contextual factors outlined in the Contact Hypothesis (Allport, 1954). White inmates scoring higher in SDO exhibited significantly less in-group bias when reporting increased contact with Black inmates (Studies 1 & 2), when perceiving that favourable contact conditions are institutionally supported (Study 1), or when experiencing more pleasant personal interactions with Black inmates (Study 2). These SDO x Contact Condition moderation effects were mediated in Study 2: among high-SDO individuals, increased empathy towards Black inmates mediated the relation between contact variables and lower in-group bias. Implications for considering individual differences and empathy in contact settings are considered.

  4. A newly recognized autosomal dominant limb girdle muscular dystrophy with cardiac involvement

    NARCIS (Netherlands)

    van der Kooi, A. J.; Ledderhof, T. M.; de Voogt, W. G.; Res, C. J.; Bouwsma, G.; Troost, D.; Busch, H. F.; Becker, A. E.; de Visser, M.

    1996-01-01

    Sixty-five members of three families with limb girdle muscular dystrophy (LGMD) underwent neurological, cardiological, and ancillary investigations. Thirty-five individuals were diagnosed as having slowly progressive autosomal dominant LGMD. Symmetrical weakness started in the proximal lower limb

  5. You never think about my feelings: interpersonal dominance as a predictor of emotion decoding accuracy.

    Science.gov (United States)

    Moeller, Sara K; Lee, Elizabeth A Ewing; Robinson, Michael D

    2011-08-01

    Dominance and submission constitute fundamentally different social interaction strategies that may be enacted most effectively to the extent that the emotions of others are relatively ignored (dominance) versus noticed (submission). On the basis of such considerations, we hypothesized a systematic relationship between chronic tendencies toward high versus low levels of interpersonal dominance and emotion decoding accuracy in objective tasks. In two studies (total N = 232), interpersonally dominant individuals exhibited poorer levels of emotion recognition in response to audio and video clips (Study 1) and facial expressions of emotion (Study 2). The results provide a novel perspective on interpersonal dominance, suggest its strategic nature (Study 2), and are discussed in relation to Fiske's (1993) social-cognitive theory of power. 2011 APA, all rights reserved

  6. Effects of 'target' plant species body size on neighbourhood species richness and composition in old-field vegetation.

    Directory of Open Access Journals (Sweden)

    Brandon S Schamp

    Full Text Available Competition is generally regarded as an important force in organizing the structure of vegetation, and evidence from several experimental studies of species mixtures suggests that larger mature plant size elicits a competitive advantage. However, these findings are at odds with the fact that large and small plant species generally coexist, and relatively smaller species are more common in virtually all plant communities. Here, we use replicates of ten relatively large old-field plant species to explore the competitive impact of target individual size on their surrounding neighbourhoods compared to nearby neighbourhoods of the same size that are not centred by a large target individual. While target individuals of the largest of our test species, Centaurea jacea L., had a strong impact on neighbouring species, in general, target species size was a weak predictor of the number of other resident species growing within its immediate neighbourhood, as well as the number of resident species that were reproductive. Thus, the presence of a large competitor did not restrict the ability of neighbouring species to reproduce. Lastly, target species size did not have any impact on the species size structure of neighbouring species; i.e. they did not restrict smaller, supposedly poorer competitors, from growing and reproducing close by. Taken together, these results provide no support for a size-advantage in competition restricting local species richness or the ability of small species to coexist and successfully reproduce in the immediate neighbourhood of a large species.

  7. Plant species composition alters the sign and strength of an emergent multi-predator effect by modifying predator foraging behaviour.

    Directory of Open Access Journals (Sweden)

    Andrew Wilby

    Full Text Available The prediction of pest-control functioning by multi-predator communities is hindered by the non-additive nature of species functioning. Such non-additivity, commonly termed an emergent multi-predator effect, is known to be affected by elements of the ecological context, such as the structure and composition of vegetation, in addition to the traits of the predators themselves. Here we report mesocosm experiments designed to test the influence of plant density and species composition (wheat monoculture or wheat and faba bean polyculture on the emergence of multi-predator effects between Adalia bipunctata and Chrysoperla carnea, in their suppression of populations of the aphid Metopolophium dirhodum. The mesocosm experiments were followed by a series of behavioural observations designed to identify how interactions among predators are modified by plant species composition and whether these effects are consistent with the observed influence of plant species composition on aphid population suppression. Although plant density was shown to have no influence on the multi-predator effect on aphid population growth, plant composition had a marked effect. In wheat monoculture, Adalia and Chrysoperla mixed treatments caused greater suppression of M. dirhodum populations than expected. However this positive emergent effect was reversed to a negative multi-predator effect in wheat and faba bean polyculture. The behavioural observations revealed that although dominant individuals did not respond to the presence of faba bean plants, the behaviour of sub-dominants was affected markedly, consistent with their foraging for extra-floral nectar produced by the faba bean. This interaction between plant composition and predator community composition on the foraging behaviour of sub-dominants is thought to underlie the observed effect of plant composition on the multi-predator effect. Thus, the emergence of multi-predator effects is shown to be strongly influenced by

  8. Superciliums in white-eared hummingbirds as badges of status signaling dominance.

    Science.gov (United States)

    González-García, Juan Manuel; Lara, Carlos; Quesada, Javier; Chávez-Zichinelli, Carlos A; Serrano-Meneses, Martín A

    2018-04-03

    The role of badges as indicators of contest ability has been previously described. In hummingbirds, the exhibition of a badge is expected to save energy expenditure in agonistic interactions and to favor energy intake. Here, we investigate whether variable supercilium size in the white-eared hummingbird has a role in dominance status signaling. Firstly, 45 hummingbird males were captured and their superciliums were photographed to investigate variation in size and any possible allometric relationships. Secondly, 42 male birds were used to analyze whether the supercilium has a role in dominance status signaling in a dyadic contest. We found that supercilium size varied continuously but that despite variability between individuals, there was no relationship between supercilium size and body size. However, our dyad experiment indicated that birds with larger badges were able to make more visits to the feeders than individuals with smaller badges. We suggest a status signaling function of the supercilium.

  9. Distribution and diversity of mangrove species in Gokana Local ...

    African Journals Online (AJOL)

    Plots 1 and 2 were dominated by Rhizophora racemosa (62.07% and 41.17% respectively). Plots 3 were dominated by R. mangle (4 1.67%) while Plots 4 had 26.56% of Acrostichum aureum and 26.56% of Phoenix reclinata. The overlapping mangrove species occurrence (Laguncularia racemosa and R. mangle) at the ...

  10. Delineating Individual Trees from Lidar Data: A Comparison of Vector- and Raster-based Segmentation Approaches

    Directory of Open Access Journals (Sweden)

    Maggi Kelly

    2013-08-01

    Full Text Available Light detection and ranging (lidar data is increasingly being used for ecosystem monitoring across geographic scales. This work concentrates on delineating individual trees in topographically-complex, mixed conifer forest across the California’s Sierra Nevada. We delineated individual trees using vector data and a 3D lidar point cloud segmentation algorithm, and using raster data with an object-based image analysis (OBIA of a canopy height model (CHM. The two approaches are compared to each other and to ground reference data. We used high density (9 pulses/m2, discreet lidar data and WorldView-2 imagery to delineate individual trees, and to classify them by species or species types. We also identified a new method to correct artifacts in a high-resolution CHM. Our main focus was to determine the difference between the two types of approaches and to identify the one that produces more realistic results. We compared the delineations via tree detection, tree heights, and the shape of the generated polygons. The tree height agreement was high between the two approaches and the ground data (r2: 0.93–0.96. Tree detection rates increased for more dominant trees (8–100 percent. The two approaches delineated tree boundaries that differed in shape: the lidar-approach produced fewer, more complex, and larger polygons that more closely resembled real forest structure.

  11. Effects of monsoon precipitation variability on the physiological response of two dominant C₄ grasses across a semiarid ecotone.

    Science.gov (United States)

    Thomey, Michell L; Collins, Scott L; Friggens, Michael T; Brown, Renee F; Pockman, William T

    2014-11-01

    For the southwestern United States, climate models project an increase in extreme precipitation events and prolonged dry periods. While most studies emphasize plant functional type response to precipitation variability, it is also important to understand the physiological characteristics of dominant plant species that define plant community composition and, in part, regulate ecosystem response to climate change. We utilized rainout shelters to alter the magnitude and frequency of rainfall and measured the physiological response of the dominant C4 grasses, Bouteloua eriopoda and Bouteloua gracilis. We hypothesized that: (1) the more drought-adapted B. eriopoda would exhibit faster recovery and higher rates of leaf-level photosynthesis (A(net)) than B. gracilis, (2) A(net) would be greater under the higher average soil water content in plots receiving 30-mm rainfall events, (3) co-dominance of B. eriopoda and B. gracilis in the ecotone would lead to intra-specific differences from the performance of each species at the site where it was dominant. Throughout the study, soil moisture explained 40-70% of the variation in A(net). Consequently, differences in rainfall treatments were not evident from intra-specific physiological function without sufficient divergence in soil moisture. Under low frequency, larger rainfall events B. gracilis exhibited improved water status and longer periods of C gain than B. eriopoda. Results from this study indicate that less frequent and larger rainfall events could provide a competitive advantage to B. gracilis and influence species composition across this arid-semiarid grassland ecotone.

  12. Detection of cryptic species

    International Nuclear Information System (INIS)

    Cockburn, A.F.; Jensen, T.; Seawright, J.A.

    1998-01-01

    Morphologically similar cryptic species are common in insects. In Anopheles mosquitoes morphologically described species are complexes of cryptic species. Cryptic species are of great practical importance for two reasons: first, one or more species of the complex might not be a pest and control efforts directed at the complex as a whole would therefore be partly wasted; and second, genetic (and perhaps biological) control strategies directed against one species of the complex would not affect other species of the complex. At least one SIT effort has failed because the released sterile insect were of a different species and therefore did not mate with the wild insects being targeted. We use a multidisciplinary approach for detection of cryptic species complexes, focusing first on identifying variability in wild populations using RFLPs of mitochondrial and ribosomal RNA genes (mtDNA and rDNA); followed by confirmation using a variety of other techniques. For rapid identification of wild individuals of field collections, we use a DNA dot blot assay. DNA probes can be isolated by differential screening, however we are currently focusing on the sequencing of the rDNA extragenic spacers. These regions are repeated several hundred times per genome in mosquitoes and evolve rapidly. Molecular drive tends to keen the individual genes homogeneous within a species. (author)

  13. From nature-dominated to human-dominated environmental changes

    Science.gov (United States)

    Messerli, Bruno; Grosjean, Martin; Hofer, Thomas; Núñez, Lautaro; Pfister, Christian

    2000-01-01

    To what extent is it realistic and useful to view human history as a sequence of changes from highly vulnerable societies of hunters and gatherers through periods with less vulnerable, well buffered and highly productive agrarian-urban societies to a world with regions of extreme overpopulation and overuse of life support systems, so that vulnerability to climatic-environmental changes and extreme events is again increasing? This question cannot be fully answered in our present state of knowledge, but at least we can try to illustrate, with three case studies from different continents, time periods and ecosystems, some fundamental changes in the relationship between natural processes and human activities that occur, as we pass from a nature-dominated to a human dominated environment. 1. Early-mid Holocene: Nature dominated environment — human adaptation, mitigation, and migration. In the central Andes, the Holocene climate changed from humid (10,800-8000 BP) to extreme arid (8000-3600 BP) conditions. Over the same period, prehistoric hunting communities adopted a more sedentary pattern of resource use by settling close to the few perennial water bodies, where they began the process of domesticating camelids around 5000 BP and irrigation from about 3100 BP. 2. Historical period: An agrarian society in transition from an "enduring" to an innovative human response. Detailed documentary evidence from Western Europe may be used to reconstruct quite precisely the impacts of climatic variations on agrarian societies. The period considered spans a major transition from an apparently passive response to the vagaries of the environment during the 16th century to an active and innovative attitude from the onset of the agrarian revolution in the late 18th century through to the present day. The associated changes in technology and in agricultural practices helped to create a society better able to survive the impact of climatic extremes. 3. The present day: A human dominated

  14. Vegetation structure of plantain-based agrosystems determines numerical dominance in community of ground-dwelling ants.

    Science.gov (United States)

    Dassou, Anicet Gbéblonoudo; Tixier, Philippe; Dépigny, Sylvain; Carval, Dominique

    2017-01-01

    In tropics, ants can represent an important part of animal biomass and are known to be involved in ecosystem services, such as pest regulation. Understanding the mechanisms underlying the structuring of local ant communities is therefore important in agroecology. In the humid tropics of Africa, plantains are cropped in association with many other annual and perennial crops. Such agrosystems differ greatly in vegetation diversity and structure and are well-suited for studying how habitat-related factors affect the ant community. We analysed abundance data for the six numerically dominant