The roles of genetic drift and natural selection in quantitative trait divergence along an altitudinal gradient in Arabidopsis thaliana.

Science.gov (United States)

Luo, Y; Widmer, A; Karrenberg, S

2015-02-01

Understanding how natural selection and genetic drift shape biological variation is a central topic in biology, yet our understanding of the agents of natural selection and their target traits is limited. We investigated to what extent selection along an altitudinal gradient or genetic drift contributed to variation in ecologically relevant traits in Arabidopsis thaliana. We collected seeds from 8 to 14 individuals from each of 14 A. thaliana populations originating from sites between 800 and 2700 m above sea level in the Swiss Alps. Seed families were grown with and without vernalization, corresponding to winter-annual and summer-annual life histories, respectively. We analyzed putatively neutral genetic divergence between these populations using 24 simple sequence repeat markers. We measured seven traits related to growth, phenology and leaf morphology that are rarely reported in A. thaliana and performed analyses of altitudinal clines, as well as overall QST-FST comparisons and correlation analyses among pair-wise QST, FST and altitude of origin differences. Multivariate analyses suggested adaptive differentiation along altitude in the entire suite of traits, particularly when expressed in the summer-annual life history. Of the individual traits, a decrease in rosette leaf number in the vegetative state and an increase in leaf succulence with increasing altitude could be attributed to adaptive divergence. Interestingly, these patterns relate well to common within- and between-species trends of smaller plant size and thicker leaves at high altitude. Our results thus offer exciting possibilities to unravel the underlying mechanisms for these conspicuous trends using the model species A. thaliana.

The Hidden Complexity of Mendelian Traits across Natural Yeast Populations

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Jing Hou

2016-07-01

Full Text Available Mendelian traits are considered to be at the lower end of the complexity spectrum of heritable phenotypes. However, more than a century after the rediscovery of Mendel’s law, the global landscape of monogenic variants, as well as their effects and inheritance patterns within natural populations, is still not well understood. Using the yeast Saccharomyces cerevisiae, we performed a species-wide survey of Mendelian traits across a large population of isolates. We generated offspring from 41 unique parental pairs and analyzed 1,105 cross/trait combinations. We found that 8.9% of the cases were Mendelian. Further tracing of causal variants revealed background-specific expressivity and modified inheritances, gradually transitioning from Mendelian to complex traits in 30% of the cases. In fact, when taking into account the natural population diversity, the hidden complexity of traits could be substantial, confounding phenotypic predictability even for simple Mendelian traits.

Journal of East African Natural History

African Journals Online (AJOL)

The Journal of East African Natural History is published jointly by the East Africa Natural History Society and the National Museums of Kenya. The Journal publishes papers and notes in the field of natural history, broadly defined as the study of organisms in their natural state, relevant to the eastern African region.

Neutral Theory: From Complex Population History to Natural Selection and Sociocultural Phenomena in Human Populations.

Science.gov (United States)

Austerlitz, Frédéric; Heyer, Evelyne

2018-06-01

Here, we present a synthetic view on how Kimura's Neutral theory has helped us gaining insight on the different evolutionary forces that shape human evolution. We put this perspective in the frame of recent emerging challenges: the use of whole genome data for reconstructing population histories, natural selection on complex polygenic traits, and integrating cultural processes in human evolution.

Francis Bacon's natural history and civil history: a comparative survey.

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Manzo, Silvia

2012-01-01

The aim of this paper is to offer a comparative survey of Bacon's theory and practice of natural history and of civil history, particularly centered on their relationship to natural philosophy and human philosophy. I will try to show that the obvious differences concerning their subject matter encompass a number of less obvious methodological and philosophical assumptions which reveal a significant practical and conceptual convergence of the two fields. Causes or axioms are prescribed as the theoretical end-products of natural history, whereas precepts are envisaged as the speculative outcomes derived from perfect civil history. In spite of this difference, causes and precepts are thought to enable effective action in order to change the state of nature and of man, respectively. For that reason a number of common patterns are to be found in Bacon's theory and practice of natural and civil history.

Invasive plants and enemy release: evolution of trait means and trait correlations in Ulex europaeus.

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Hornoy, Benjamin; Tarayre, Michèle; Hervé, Maxime; Gigord, Luc; Atlan, Anne

2011-01-01

Several hypotheses that attempt to explain invasive processes are based on the fact that plants have been introduced without their natural enemies. Among them, the EICA (Evolution of Increased Competitive Ability) hypothesis is the most influential. It states that, due to enemy release, exotic plants evolve a shift in resource allocation from defence to reproduction or growth. In the native range of the invasive species Ulex europaeus, traits involved in reproduction and growth have been shown to be highly variable and genetically correlated. Thus, in order to explore the joint evolution of life history traits and susceptibility to seed predation in this species, we investigated changes in both trait means and trait correlations. To do so, we compared plants from native and invaded regions grown in a common garden. According to the expectations of the EICA hypothesis, we observed an increase in seedling height. However, there was little change in other trait means. By contrast, correlations exhibited a clear pattern: the correlations between life history traits and infestation rate by seed predators were always weaker in the invaded range than in the native range. In U. europaeus, the role of enemy release in shaping life history traits thus appeared to imply trait correlations rather than trait means. In the invaded regions studied, the correlations involving infestation rates and key life history traits such as flowering phenology, growth and pod density were reduced, enabling more independent evolution of these key traits and potentially facilitating local adaptation to a wide range of environments. These results led us to hypothesise that a relaxation of genetic correlations may be implied in the expansion of invasive species.

Invasive plants and enemy release: evolution of trait means and trait correlations in Ulex europaeus.

Directory of Open Access Journals (Sweden)

Benjamin Hornoy

Full Text Available Several hypotheses that attempt to explain invasive processes are based on the fact that plants have been introduced without their natural enemies. Among them, the EICA (Evolution of Increased Competitive Ability hypothesis is the most influential. It states that, due to enemy release, exotic plants evolve a shift in resource allocation from defence to reproduction or growth. In the native range of the invasive species Ulex europaeus, traits involved in reproduction and growth have been shown to be highly variable and genetically correlated. Thus, in order to explore the joint evolution of life history traits and susceptibility to seed predation in this species, we investigated changes in both trait means and trait correlations. To do so, we compared plants from native and invaded regions grown in a common garden. According to the expectations of the EICA hypothesis, we observed an increase in seedling height. However, there was little change in other trait means. By contrast, correlations exhibited a clear pattern: the correlations between life history traits and infestation rate by seed predators were always weaker in the invaded range than in the native range. In U. europaeus, the role of enemy release in shaping life history traits thus appeared to imply trait correlations rather than trait means. In the invaded regions studied, the correlations involving infestation rates and key life history traits such as flowering phenology, growth and pod density were reduced, enabling more independent evolution of these key traits and potentially facilitating local adaptation to a wide range of environments. These results led us to hypothesise that a relaxation of genetic correlations may be implied in the expansion of invasive species.

Antiherbivore defenses alter natural selection on plant reproductive traits.

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Thompson, Ken A; Johnson, Marc T J

2016-04-01

While many studies demonstrate that herbivores alter selection on plant reproductive traits, little is known about whether antiherbivore defenses affect selection on these traits. We hypothesized that antiherbivore defenses could alter selection on reproductive traits by altering trait expression through allocation trade-offs, or by altering interactions with mutualists and/or antagonists. To test our hypothesis, we used white clover, Trifolium repens, which has a Mendelian polymorphism for the production of hydrogen cyanide-a potent antiherbivore defense. We conducted a common garden experiment with 185 clonal families of T. repens that included cyanogenic and acyanogenic genotypes. We quantified resistance to herbivores, and selection on six floral traits and phenology via male and female fitness. Cyanogenesis reduced herbivory but did not alter the expression of reproductive traits through allocation trade-offs. However, the presence of cyanogenic defenses altered natural selection on petal morphology and the number of flowers within inflorescences via female fitness. Herbivory influenced selection on flowers and phenology via female fitness independently of cyanogenesis. Our results demonstrate that both herbivory and antiherbivore defenses alter natural selection on plant reproductive traits. We discuss the significance of these results for understanding how antiherbivore defenses interact with herbivores and pollinators to shape floral evolution. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Quantitative genetic analysis of life-history traits of Caenorhabditis elegans in stressful environments

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Shorto Alison

2008-01-01

Full Text Available Abstract Background Organisms live in environments that vary. For life-history traits that vary across environments, fitness will be maximised when the phenotype is appropriately matched to the environmental conditions. For the free-living nematode Caenorhabditis elegans, we have investigated how two major life-history traits, (i the development of environmentally resistant dauer larvae and (ii reproduction, respond to environmental stress (high population density and low food availability, and how these traits vary between lines and the genetic basis of this variation. Results We found that lines of C. elegans vary in their phenotypic plasticity of dauer larva development, i.e. there is variation in the likelihood of developing into a dauer larva for the same environmental change. There was also variation in how lifetime fecundity and the rate of reproduction changed under conditions of environmental stress. These traits were related, such that lines that are highly plastic for dauer larva development also maintain a high population growth rate when stressed. We identified quantitative trait loci (QTL on two chromosomes that control the dauer larva development and population size phenotypes. The QTLs affecting the dauer larva development and population size phenotypes on chromosome II are closely linked, but are genetically separable. This chromosome II QTL controlling dauer larva development does not encompass any loci previously identified to control dauer larva development. This chromosome II region contains many predicted 7-transmembrane receptors. Such proteins are often involved in information transduction, which is clearly relevant to the control of dauer larva development. Conclusion C. elegans alters both its larval development and adult reproductive strategy in response to environmental stress. Together the phenotypic and genotypic data suggest that these two major life-history traits are co-ordinated responses to environmental stress

The Case for Natural History

DEFF Research Database (Denmark)

King, Heather; Achiam, Marianne

2017-01-01

on the educational value afforded by understanding the epistemological bases of natural history and its particular forms of reasoning. We also briefly discuss the ways in which an education in natural history provides the foundation for environmental and social justice efforts that directly affect the lives of young...

Life history traits of Bathyclarias nyasensis (Siluroidei) in Lake Malawi

African Journals Online (AJOL)

Life history traits, including age, growth, reproduction and diet of Bathyclarias nyasensis from Lake Malawi were studied between December 1996 and November 1998. Owing to reabsorp tion of pectoral spines with increasing fish size, and the relatively low number of spines that could be aged reliably, only otoliths were ...

Egyptian Journal of Natural History

African Journals Online (AJOL)

The Egyptian Journal of Natural History publishes taxonomic and faunistic studies, or field-based research involving the natural history of the Egyptian fauna and flora. Both short and long papers are welcomed. We particularly encourage studies on Sinai.View the Instructions for authors All papers are reviewed by at least ...

Marine reserves: fish life history and ecological traits matter.

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Claudet, J; Osenberg, C W; Domenici, P; Badalamenti, F; Milazzo, M; Falcón, J M; Bertocci, I; Benedetti-Cecchi, L; García-Charton, J A; Goñi, R; Borg, J A; Forcada, A; De Lucia, G A; Perez-Ruzafa, A; Afonso, P; Brito, A; Guala, I; Le Diréach, L; Sanchez-Jerez, P; Somerfield, P J; Planes, S

2010-04-01

Marine reserves are assumed to protect a wide range of species from deleterious effects stemming from exploitation. However, some species, due to their ecological characteristics, may not respond positively to protection. Very little is known about the effects of life history and ecological traits (e.g., mobility, growth, and habitat) on responses of fish species to marine reserves. Using 40 data sets from 12 European marine reserves, we show that there is significant variation in the response of different species of fish to protection and that this heterogeneity can be explained, in part, by differences in their traits. Densities of targeted size-classes of commercial species were greater in protected than unprotected areas. This effect of protection increased as the maximum body size of the targeted species increased, and it was greater for species that were not obligate schoolers. However, contrary to previous theoretical findings, even mobile species with wide home ranges benefited from protection: the effect of protection was at least as strong for mobile species as it was for sedentary ones. Noncommercial bycatch and unexploited species rarely responded to protection, and when they did (in the case of unexploited bentho-pelagic species), they exhibited the opposite response: their densities were lower inside reserves. The use of marine reserves for marine conservation and fisheries management implies that they should ensure protection for a wide range of species with different life-history and ecological traits. Our results suggest this is not the case, and instead that effects vary with economic value, body size, habitat, depth range, and schooling behavior.

Quantitative genetic methods depending on the nature of the phenotypic trait.

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de Villemereuil, Pierre

2018-01-24

A consequence of the assumptions of the infinitesimal model, one of the most important theoretical foundations of quantitative genetics, is that phenotypic traits are predicted to be most often normally distributed (so-called Gaussian traits). But phenotypic traits, especially those interesting for evolutionary biology, might be shaped according to very diverse distributions. Here, I show how quantitative genetics tools have been extended to account for a wider diversity of phenotypic traits using first the threshold model and then more recently using generalized linear mixed models. I explore the assumptions behind these models and how they can be used to study the genetics of non-Gaussian complex traits. I also comment on three recent methodological advances in quantitative genetics that widen our ability to study new kinds of traits: the use of "modular" hierarchical modeling (e.g., to study survival in the context of capture-recapture approaches for wild populations); the use of aster models to study a set of traits with conditional relationships (e.g., life-history traits); and, finally, the study of high-dimensional traits, such as gene expression. © 2018 New York Academy of Sciences.

The genetic basis of natural variation in oenological traits in Saccharomyces cerevisiae.

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Francisco Salinas

Full Text Available Saccharomyces cerevisiae is the main microorganism responsible for wine alcoholic fermentation. The oenological phenotypes resulting from fermentation, such as the production of acetic acid, glycerol, and residual sugar concentration are regulated by multiple genes and vary quantitatively between different strain backgrounds. With the aim of identifying the quantitative trait loci (QTLs that regulate oenological phenotypes, we performed linkage analysis using three crosses between highly diverged S. cerevisiae strains. Segregants from each cross were used as starter cultures for 20-day fermentations, in synthetic wine must, to simulate actual winemaking conditions. Linkage analysis on phenotypes of primary industrial importance resulted in the mapping of 18 QTLs. We tested 18 candidate genes, by reciprocal hemizygosity, for their contribution to the observed phenotypic variation, and validated five genes and the chromosome II right subtelomeric region. We observed that genes involved in mitochondrial metabolism, sugar transport, nitrogen metabolism, and the uncharacterized ORF YJR030W explained most of the phenotypic variation in oenological traits. Furthermore, we experimentally validated an exceptionally strong epistatic interaction resulting in high level of succinic acid between the Sake FLX1 allele and the Wine/European MDH2 allele. Overall, our work demonstrates the complex genetic basis underlying wine traits, including natural allelic variation, antagonistic linked QTLs and complex epistatic interactions between alleles from strains with different evolutionary histories.

Population dynamics, life-history traits of and habitat use by two ...

African Journals Online (AJOL)

Population dynamics and life-history traits of two sympatric nothobranchiid killifishes, Epiplatys bifasciatus and E. spilargyreius, were studied for 24 months in an intermittent stream in the Kainji Lake Basin, Nigeria. Epiplatys bifasciatus was more abundant throughout the study period, but monthly abundance of both species ...

Conserved G-matrices of morphological and life-history traits among continental and island blue tit populations.

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Delahaie, B; Charmantier, A; Chantepie, S; Garant, D; Porlier, M; Teplitsky, C

2017-08-01

The genetic variance-covariance matrix (G-matrix) summarizes the genetic architecture of multiple traits. It has a central role in the understanding of phenotypic divergence and the quantification of the evolutionary potential of populations. Laboratory experiments have shown that G-matrices can vary rapidly under divergent selective pressures. However, because of the demanding nature of G-matrix estimation and comparison in wild populations, the extent of its spatial variability remains largely unknown. In this study, we investigate spatial variation in G-matrices for morphological and life-history traits using long-term data sets from one continental and three island populations of blue tit (Cyanistes caeruleus) that have experienced contrasting population history and selective environment. We found no evidence for differences in G-matrices among populations. Interestingly, the phenotypic variance-covariance matrices (P) were divergent across populations, suggesting that using P as a substitute for G may be inadequate. These analyses also provide the first evidence in wild populations for additive genetic variation in the incubation period (that is, the period between last egg laid and hatching) in all four populations. Altogether, our results suggest that G-matrices may be stable across populations inhabiting contrasted environments, therefore challenging the results of previous simulation studies and laboratory experiments.

Rapid evolution of parasite life history traits on an expanding range-edge.

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Kelehear, Crystal; Brown, Gregory P; Shine, Richard

2012-04-01

Parasites of invading species undergoing range advance may be exposed to powerful new selective forces. Low host density in range-edge populations hampers parasite transmission, requiring the parasite to survive longer periods in the external environment before encountering a potential host. These conditions should favour evolutionary shifts in offspring size to maximise parasite transmission. We conducted a common-garden experiment to compare life history traits among seven populations of the nematode lungworm (Rhabdias pseudosphaerocephala) spanning from the parasite population core to the expanding range-edge in invasive cane toads (Rhinella marina) in tropical Australia. Compared to conspecifics from the population core, nematodes from the range-edge exhibited larger eggs, larger free-living adults and larger infective larvae, and reduced age at maturity in parasitic adults. These results support a priori predictions regarding adaptive changes in offspring size as a function of invasion history, and suggest that parasite life history traits can evolve rapidly in response to the selective forces exerted by a biological invasion. © 2012 Blackwell Publishing Ltd/CNRS.

Natural Genetic Variation and Candidate Genes for Morphological Traits in Drosophila melanogaster

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Carreira, Valeria Paula; Mensch, Julián; Hasson, Esteban; Fanara, Juan José

2016-01-01

Body size is a complex character associated to several fitness related traits that vary within and between species as a consequence of environmental and genetic factors. Latitudinal and altitudinal clines for different morphological traits have been described in several species of Drosophila and previous work identified genomic regions associated with such variation in D. melanogaster. However, the genetic factors that orchestrate morphological variation have been barely studied. Here, our main objective was to investigate genetic variation for different morphological traits associated to the second chromosome in natural populations of D. melanogaster along latitudinal and altitudinal gradients in Argentina. Our results revealed weak clinal signals and a strong population effect on morphological variation. Moreover, most pairwise comparisons between populations were significant. Our study also showed important within-population genetic variation, which must be associated to the second chromosome, as the lines are otherwise genetically identical. Next, we examined the contribution of different candidate genes to natural variation for these traits. We performed quantitative complementation tests using a battery of lines bearing mutated alleles at candidate genes located in the second chromosome and six second chromosome substitution lines derived from natural populations which exhibited divergent phenotypes. Results of complementation tests revealed that natural variation at all candidate genes studied, invected, Fasciclin 3, toucan, Reticulon-like1, jing and CG14478, affects the studied characters, suggesting that they are Quantitative Trait Genes for morphological traits. Finally, the phenotypic patterns observed suggest that different alleles of each gene might contribute to natural variation for morphological traits. However, non-additive effects cannot be ruled out, as wild-derived strains differ at myriads of second chromosome loci that may interact

Environmental effects on growth, reproduction, and life-history traits of loggerhead turtles

NARCIS (Netherlands)

Marn, Nina; Jusup, Marko; Legović, Tarzan; Kooijman, S. A.L.M.; Klanjšček, Tin

2017-01-01

Understanding the relationship between the environmental conditions and life-history traits (such as growth, reproduction, and size at specific life stages) is important for understanding the population dynamics of a species and for constructing adaptable, relevant, and efficient conservation

Genetic and life-history trait variation of the amphipod Melita plumulosa from polluted and unpolluted waterways in eastern Australia

International Nuclear Information System (INIS)

Chung, Pann Pann; Hyne, Ross V.; Mann, Reinier M.; Ballard, J. William O.

2008-01-01

To monitor genetic diversity and environmental contamination in eastern Australia, toxicity studies have employed the sensitive benthic amphipod Melita plumulosa. The goal of this study was to examine the genetic and life-history variability of natural populations of M. plumulosa from the Parramatta (polluted) and Hawkesbury (unpolluted) Rivers. The underlying genetics of the populations in these distinct waterways was examined at one mitochondrial (cytochrome c oxidase subunit I (COI)) and one nuclear (ribosomal internal transcribed spacer region 1 (ITS1)) locus. Seven unique haplotypes for COI were found amongst animals from the Parramatta River, while animals from the Hawkesbury River showed a complete absence of genetic variation at this locus. At ITS1 a total of two sequence variants were found amongst Parramatta River amphipods and three sequence variants among Hawkesbury River animals, with no common variants across the two river systems. To establish whether genetic differences were associated with organismal responses to toxicant exposure, two life-history trait variables (female head length as an estimator of amphipod size and female fecundity) were analyzed. Life-history trait analyses showed that females from the Hawkesbury River were significantly larger and more fecund. These data have critical implications for toxicity tests, the use of laboratory cultures for testing purposes, and environmental contamination in Sydney Harbor

Genetic and life-history trait variation of the amphipod Melita plumulosa from polluted and unpolluted waterways in eastern Australia

Energy Technology Data Exchange (ETDEWEB)

Chung, Pann Pann [Evolution and Ecology Research Centre, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052 (Australia); Hyne, Ross V. [Ecotoxicology and Environmental Contaminants Section, NSW Department of Environment and Climate Change, PO Box 29, Lidcombe, NSW 1825 (Australia); Mann, Reinier M. [Centre for Ecotoxicology, Department of Environmental Sciences, University of Technology-Sydney, C/-PO Box 29, Lidcombe, NSW 1825 (Australia); Ballard, J. William O. [Evolution and Ecology Research Centre, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052 (Australia)], E-mail: w.ballard@unsw.edu.au

2008-09-15

To monitor genetic diversity and environmental contamination in eastern Australia, toxicity studies have employed the sensitive benthic amphipod Melita plumulosa. The goal of this study was to examine the genetic and life-history variability of natural populations of M. plumulosa from the Parramatta (polluted) and Hawkesbury (unpolluted) Rivers. The underlying genetics of the populations in these distinct waterways was examined at one mitochondrial (cytochrome c oxidase subunit I (COI)) and one nuclear (ribosomal internal transcribed spacer region 1 (ITS1)) locus. Seven unique haplotypes for COI were found amongst animals from the Parramatta River, while animals from the Hawkesbury River showed a complete absence of genetic variation at this locus. At ITS1 a total of two sequence variants were found amongst Parramatta River amphipods and three sequence variants among Hawkesbury River animals, with no common variants across the two river systems. To establish whether genetic differences were associated with organismal responses to toxicant exposure, two life-history trait variables (female head length as an estimator of amphipod size and female fecundity) were analyzed. Life-history trait analyses showed that females from the Hawkesbury River were significantly larger and more fecund. These data have critical implications for toxicity tests, the use of laboratory cultures for testing purposes, and environmental contamination in Sydney Harbor.

Francis Bacon and the classification of natural history.

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Anstey, Peter

2012-01-01

This paper analyses the place of natural history within Bacon's divisions of the sciences in The Advancement of Learning (1605) and the later De dignitate et augmentis scientiarum (1623). It is shown that at various points in Bacon's divisions, natural history converges or overlaps with natural philosophy, and that, for Bacon, natural history and natural philosophy are not discrete disciplines. Furthermore, it is argued that Bacon's distinction between operative and speculative natural philosophy and the place of natural history within this distinction, are discontinuous with the later distinction between experimental and speculative philosophy that emerged in the methodology of the Fellows of the early Royal Society.

Darwin's Difficulties and Students' Struggles with Trait Loss: Cognitive-Historical Parallelisms in Evolutionary Explanation

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Ha, Minsu; Nehm, Ross H.

2014-05-01

Although historical changes in scientific ideas sometimes display striking similarities with students' conceptual progressions, some scholars have cautioned that such similarities lack meaningful commonalities. In the history of evolution, while Darwin and his contemporaries often used natural selection to explain evolutionary trait gain or increase, they struggled to use it to convincingly account for cases of trait loss or decrease. This study examines Darwin's evolutionary writings about trait gain and loss in the Origin of Species (On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. D. Appleton, New York, 1859) and compares them to written evolutionary explanations for trait gain and loss in a large (n > 500), cross-cultural and cross-sectional sample (novices and experts from the USA and Korea). Findings indicate that significantly more students and experts applied natural selection to cases of trait gain, but like Darwin and his contemporaries, they more often applied `use and disuse' and `inheritance of acquired characteristics' to episodes of trait loss. Although the parallelism between Darwin's difficulties and students' struggles with trait loss are striking, significant differences also characterize explanatory model structure. Overall, however, students and scientists struggles to explain trait loss—which is a very common phenomenon in the history of life—appear to transcend time, place, and level of biological expertise. The significance of these findings for evolution education are discussed; in particular, the situated nature of biological reasoning, and the important role that the history of science can play in understanding cognitive constraints on science learning.

Journal of East African Natural History: Editorial Policies

African Journals Online (AJOL)

Focus and Scope. The Journal of East African Natural History is published jointly by the East Africa Natural History Society and the National Museums of Kenya. The Journal publishes papers and notes in the field of natural history, broadly defined as the study of organisms in their natural state, relevant to the eastern African ...

Cancer and life-history traits: lessons from host-parasite interactions.

Science.gov (United States)

Ujvari, Beata; Beckmann, Christa; Biro, Peter A; Arnal, Audrey; Tasiemski, Aurelie; Massol, Francois; Salzet, Michel; Mery, Frederic; Boidin-Wichlacz, Celine; Misse, Dorothee; Renaud, Francois; Vittecoq, Marion; Tissot, Tazzio; Roche, Benjamin; Poulin, Robert; Thomas, Frederic

2016-04-01

Despite important differences between infectious diseases and cancers, tumour development (neoplasia) can nonetheless be closely compared to infectious disease because of the similarity of their effects on the body. On this basis, we predict that many of the life-history (LH) responses observed in the context of host-parasite interactions should also be relevant in the context of cancer. Parasites are thought to affect LH traits of their hosts because of strong selective pressures like direct and indirect mortality effects favouring, for example, early maturation and reproduction. Cancer can similarly also affect LH traits by imposing direct costs and/or indirectly by triggering plastic adjustments and evolutionary responses. Here, we discuss how and why a LH focus is a potentially productive but under-exploited research direction for cancer research, by focusing our attention on similarities between infectious disease and cancer with respect to their effects on LH traits and their evolution. We raise the possibility that LH adjustments can occur in response to cancer via maternal/paternal effects and that these changes can be heritable to (adaptively) modify the LH traits of their offspring. We conclude that LH adjustments can potentially influence the transgenerational persistence of inherited oncogenic mutations in populations.

Evolution and the Growth Process: Natural Selection of Entrepreneurial Traits.

Science.gov (United States)

Galor, Oded; Michalopoulos, Stelios

2012-03-01

This research suggests that a Darwinian evolution of entrepreneurial spirit played a significant role in the process of economic development and the dynamics of inequality within and across societies. The study argues that entrepreneurial spirit evolved non-monotonically in the course of human history. In early stages of development, risk-tolerant, growth promoting traits generated an evolutionary advantage and their increased representation accelerated the pace of technological progress and the process of economic development. In mature stages of development, however, risk-averse traits gained an evolutionary advantage, diminishing the growth potential of advanced economies and contributing to convergence in economic growth across countries.

Fast life history traits promote invasion success in amphibians and reptiles.

Science.gov (United States)

Allen, William L; Street, Sally E; Capellini, Isabella

2017-02-01

Competing theoretical models make different predictions on which life history strategies facilitate growth of small populations. While 'fast' strategies allow for rapid increase in population size and limit vulnerability to stochastic events, 'slow' strategies and bet-hedging may reduce variance in vital rates in response to stochasticity. We test these predictions using biological invasions since founder alien populations start small, compiling the largest dataset yet of global herpetological introductions and life history traits. Using state-of-the-art phylogenetic comparative methods, we show that successful invaders have fast traits, such as large and frequent clutches, at both establishment and spread stages. These results, together with recent findings in mammals and plants, support 'fast advantage' models and the importance of high potential population growth rate. Conversely, successful alien birds are bet-hedgers. We propose that transient population dynamics and differences in longevity and behavioural flexibility can help reconcile apparently contrasting results across terrestrial vertebrate classes. © 2017 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

Evolution and the Growth Process: Natural Selection of Entrepreneurial Traits*

Science.gov (United States)

Galor, Oded; Michalopoulos, Stelios

2013-01-01

This research suggests that a Darwinian evolution of entrepreneurial spirit played a significant role in the process of economic development and the dynamics of inequality within and across societies. The study argues that entrepreneurial spirit evolved non-monotonically in the course of human history. In early stages of development, risk-tolerant, growth promoting traits generated an evolutionary advantage and their increased representation accelerated the pace of technological progress and the process of economic development. In mature stages of development, however, risk-averse traits gained an evolutionary advantage, diminishing the growth potential of advanced economies and contributing to convergence in economic growth across countries. PMID:25089059

A Bias for the Natural? Children's Beliefs about Traits Acquired through Effort, Bribes, or Medicine

Science.gov (United States)

Lockhart, Kristi L.; Keil, Frank C.; Aw, Justine

2013-01-01

Three studies compared beliefs about natural and late blooming positive traits with those acquired through personal effort, extrinsic rewards or medicine. Young children (5-6 years), older children (8-13 years), and adults all showed a strong bias for natural and late blooming traits over acquired traits. All age groups, except 8- to 10-year-olds,…

Selection on a Subunit of the NURF Chromatin Remodeler Modifies Life History Traits in a Domesticated Strain of Caenorhabditis elegans.

Directory of Open Access Journals (Sweden)

Edward E Large

2016-07-01

Full Text Available Evolutionary life history theory seeks to explain how reproductive and survival traits are shaped by selection through allocations of an individual's resources to competing life functions. Although life-history traits evolve rapidly, little is known about the genetic and cellular mechanisms that control and couple these tradeoffs. Here, we find that two laboratory-adapted strains of C. elegans descended from a single common ancestor that lived in the 1950s have differences in a number of life-history traits, including reproductive timing, lifespan, dauer formation, growth rate, and offspring number. We identified a quantitative trait locus (QTL of large effect that controls 24%-75% of the total trait variance in reproductive timing at various timepoints. Using CRISPR/Cas9-induced genome editing, we show this QTL is due in part to a 60 bp deletion in the 3' end of the nurf-1 gene, which is orthologous to the human gene encoding the BPTF component of the NURF chromatin remodeling complex. Besides reproduction, nurf-1 also regulates growth rate, lifespan, and dauer formation. The fitness consequences of this deletion are environment specific-it increases fitness in the growth conditions where it was fixed but decreases fitness in alternative laboratory growth conditions. We propose that chromatin remodeling, acting through nurf-1, is a pleiotropic regulator of life history trade-offs underlying the evolution of multiple traits across different species.

The Naturalized Nation: Anchoring, Objectification and Naturalized Social Representations of History

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Eemeli Hakoköngäs

2016-12-01

Full Text Available This study focuses on the connection between social representations of history and collective memory from the perspective of elementary concepts of social representations theory: anchoring, objectification and naturalization. The aims of the study are to arrive at a conceptual clarity of this connection and demonstrate how to apply basic concepts of social representations theory to the study of collective memory. The study also focuses on the naturalized characteristics of Finnish history. The data consist of the covers of twenty Finnish history books between the years 1965 and 2014. All the covers are embellished with typography or visual images. The covers were analysed using a semiotic approach in which the interest is in the description (denotation, the associations (connotation and the meaning system these construe (myth. The analysis shows how national history is concretized with visual images (objectification, how the meaning of representation is conveyed (anchoring and how collective memory is maintained (naturalization, transmitted and shaped during the years. The results show how the stable collective memories and changing social representations of history are interacting. The most frequently used visual element was the colour blue, which alludes to the Finnish flag, a symbol of the nation that represents the core of Finnish history. The study suggests that it is possible to conceptualize collective memories as naturalized social representations of history. It shows how processes of anchoring and objectification serve as tools of collective memory and how the naturalized conceptions are subtly changed. In addition, the study develops the use of visual semiotic analysis in social representations research.

Natural histories of chronic obstructive pulmonary disease

DEFF Research Database (Denmark)

Rennard, Stephen I; Vestbo, Jørgen

2008-01-01

Concepts relating to the natural history of chronic obstructive pulmonary disease (COPD) arise most importantly from the classic study of Fletcher and colleagues (The Natural History of Chronic Bronchitis and Emphysema, Oxford University Press, New York, 1976). This study, which evaluated working...

Mutation accumulation may be a minor force in shaping life history traits

DEFF Research Database (Denmark)

Dańko, Maciej Jan; Kozłowski, Jan; Vaupel, James Walton

2012-01-01

-strings to capture different age-specific mutational patterns. Each pattern represents a genotype and for each genotype we find the life history strategy that maximizes fitness. Genotypes compete with each other and are subject to selection and to new mutations over generations until equilibrium in gene......-frequencies is reached. The mutation-selection equilibrium provides information about mutational load and the differential effects of mutations on a life history trait--the optimal age at maturity. We find that mutations accumulate only at ages with negligible impact on fitness and that mutation accumulation has very...

Evolutionary history of the recruitment of conserved developmental genes in association to the formation and diversification of a novel trait

Directory of Open Access Journals (Sweden)

Shirai Leila T

2012-02-01

Full Text Available Abstract Background The origin and modification of novel traits are important aspects of biological diversification. Studies combining concepts and approaches of developmental genetics and evolutionary biology have uncovered many examples of the recruitment, or co-option, of genes conserved across lineages for the formation of novel, lineage-restricted traits. However, little is known about the evolutionary history of the recruitment of those genes, and of the relationship between them -for example, whether the co-option involves whole or parts of existing networks, or whether it occurs by redeployment of individual genes with de novo rewiring. We use a model novel trait, color pattern elements on butterfly wings called eyespots, to explore these questions. Eyespots have greatly diversified under natural and sexual selection, and their formation involves genetic circuitries shared across insects. Results We investigated the evolutionary history of the recruitment and co-recruitment of four conserved transcription regulators to the larval wing disc region where circular pattern elements develop. The co-localization of Antennapedia, Notch, Distal-less, and Spalt with presumptive (eyespot organizers was examined in 13 butterfly species, providing the largest comparative dataset available for the system. We found variation between families, between subfamilies, and between tribes. Phylogenetic reconstructions by parsimony and maximum likelihood methods revealed an unambiguous evolutionary history only for Antennapedia, with a resolved single origin of eyespot-associated expression, and many homoplastic events for Notch, Distal-less, and Spalt. The flexibility in the (co-recruitment of the targeted genes includes cases where different gene combinations are associated with morphologically similar eyespots, as well as cases where identical protein combinations are associated with very different phenotypes. Conclusions The evolutionary history of gene

Effects of medium renewal and handling stress on life history traits in Daphnia

NARCIS (Netherlands)

Rousseaux, S.; Vanoverbeke, J.; Aerts, J.; Declerck, S.A.J.

2010-01-01

The zooplankton genus Daphnia is used as a model organism in ecological, ecotoxicological and evolutionary research. It is often used in experimental laboratory setups to examine life history traits under a variety of factors inducing stress. One type of stress, handling stress because of

Climate-driven changes in life-history traits of the bastard grunt (Pomadasys incisus in the north-western Mediterranean

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H. VILLEGAS-HERNÁNDEZ

2014-07-01

Full Text Available This study evaluates the influence of sea water temperature on the life-history traits of the thermophilic bastard grunt Pomadasys incisus in the Catalan coast. We compared two key traits of this species, condition and reproduction, from populations in two separate areas with different thermal regimes: the Gulf of Roses (cold area and the Ebre Delta (warm area. Specimens were collected monthly from each area between 2010 and 2012. The results were also compared with those given in the literature from sites where the species is more common, i.e. the southern Mediterranean and eastern Atlantic. Our findings indicate that, compared to the populations in warmer environments, the population inhabiting the colder waters appears to be in significantly poorer condition and there is some deviance in their life-history traits: egg size and quality being traded-off for higher egg numbers; lower lengths at maturity and alterations to spawning phenology. A certain degree of plasticity in life-history traits may favour the process of expansion and establishment of this thermophilic species into newly available but colder habitats of the north-western Mediterranean under a scenario of climate change.

Heritability, covariation and natural selection on 24 traits of common evening primrose (Oenothera biennis) from a field experiment.

Science.gov (United States)

Johnson, M T J; Agrawal, A A; Maron, J L; Salminen, J-P

2009-06-01

This study explored genetic variation and co-variation in multiple functional plant traits. Our goal was to characterize selection, heritabilities and genetic correlations among different types of traits to gain insight into the evolutionary ecology of plant populations and their interactions with insect herbivores. In a field experiment, we detected significant heritable variation for each of 24 traits of Oenothera biennis and extensive genetic covariance among traits. Traits with diverse functions formed several distinct groups that exhibited positive genetic covariation with each other. Genetic variation in life-history traits and secondary chemistry together explained a large proportion of variation in herbivory (r(2) = 0.73). At the same time, selection acted on lifetime biomass, life-history traits and two secondary compounds of O. biennis, explaining over 95% of the variation in relative fitness among genotypes. The combination of genetic covariances and directional selection acting on multiple traits suggests that adaptive evolution of particular traits is constrained, and that correlated evolution of groups of traits will occur, which is expected to drive the evolution of increased herbivore susceptibility. As a whole, our study indicates that an examination of genetic variation and covariation among many different types of traits can provide greater insight into the evolutionary ecology of plant populations and plant-herbivore interactions.

Role of trait shame in the association between posttraumatic stress and aggression among men with a history of interpersonal trauma.

Science.gov (United States)

Schoenleber, Michelle; Sippel, Lauren M; Jakupcak, Matthew; Tull, Matthew T

2015-01-01

Given the theoretical and empirical associations among posttraumatic stress, shame, and interpersonal aggression, this study examined whether trait shame accounts for the associations between posttraumatic stress and aggressive behavior in a sample of 103 men with a history of interpersonal trauma. Results indicated that trait shame accounted for the associations of posttraumatic stress with the variety of both physically and psychologically aggressive behavior, as well as with the frequency of physical aggression. This study also examined trait guilt, given its conceptual relationship to both shame and posttraumatic stress; unlike trait shame, trait guilt did not account for the association between posttraumatic stress and the variety of physically aggressive acts. Additionally, although trait guilt reduced the association between posttraumatic stress and the frequency of physical aggression, the indirect path including guilt was nonsignificant. Taken together, the present study supports existing theories suggesting that shame, but not guilt, may contribute to aggressive behavior, especially among individuals with histories of traumatic exposure. (c) 2015 APA, all rights reserved).

Repeatable aversion across threat types is linked with life-history traits but is dependent on how aversion is measured.

Science.gov (United States)

Davidson, Gabrielle L; Reichert, Michael S; Crane, Jodie M S; O'Shea, William; Quinn, John L

2018-02-01

Personality research suggests that individual differences in risk aversion may be explained by links with life-history variation. However, few empirical studies examine whether repeatable differences in risk avoidance behaviour covary with life-history traits among individuals in natural populations, or how these links vary depending on the context and the way risk aversion is measured. We measured two different risk avoidance behaviours (latency to enter the nest and inspection time) in wild great tits ( Parus major ) in two different contexts-response to a novel object and to a predator cue placed at the nest-box during incubation---and related these behaviours to female reproductive success and condition. Females responded equally strongly to both stimuli, and although both behaviours were repeatable, they did not correlate. Latency to enter was negatively related to body condition and the number of offspring fledged. By contrast, inspection time was directly explained by whether incubating females had been flushed from the nest before the trial began. Thus, our inferences on the relationship between risk aversion and fitness depend on how risk aversion was measured. Our results highlight the limitations of drawing conclusions about the relevance of single measures of a personality trait such as risk aversion.

Adaptive value of phenological traits in stressful environments: predictions based on seed production and laboratory natural selection.

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Benjamin Brachi

Full Text Available Phenological traits often show variation within and among natural populations of annual plants. Nevertheless, the adaptive value of post-anthesis traits is seldom tested. In this study, we estimated the adaptive values of pre- and post-anthesis traits in two stressful environments (water stress and interspecific competition, using the selfing annual species Arabidopsis thaliana. By estimating seed production and by performing laboratory natural selection (LNS, we assessed the strength and nature (directional, disruptive and stabilizing of selection acting on phenological traits in A. thaliana under the two tested stress conditions, each with four intensities. Both the type of stress and its intensity affected the strength and nature of selection, as did genetic constraints among phenological traits. Under water stress, both experimental approaches demonstrated directional selection for a shorter life cycle, although bolting time imposes a genetic constraint on the length of the interval between bolting and anthesis. Under interspecific competition, results from the two experimental approaches showed discrepancies. Estimation of seed production predicted directional selection toward early pre-anthesis traits and long post-anthesis periods. In contrast, the LNS approach suggested neutrality for all phenological traits. This study opens questions on adaptation in complex natural environment where many selective pressures act simultaneously.

Francis Bacon: constructing natural histories of the invisible.

Science.gov (United States)

Rusu, Doina-Cristina

2012-01-01

The natural histories contained in Francis Bacon's Historia naturalis et experimentalis seem to differ from the model presented in De augmentis scientiarum and the Descriptio globi intellectualis in that they are focused on the defining properties of matter, its primary schematisms and the spirits. In this respect, they are highly speculative. In this paper I aim to describe the Historia naturalis et experimentalis as a text about matter theory, the histories of which are ascending from what is most evident to the senses to what is least accessible to them. Moreover, the Latin natural histories are parts of a methodological procedure in which the provisional rules and axioms obtained in one history can be used as theoretical assumptions for another history, thereby permitting one to delve ever more profoundly into the structure of nature.

Life-history traits in an evergreen Mediterranean oak respond differentially to previous experimental environments

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J. M. Rey Benayas

2008-06-01

Full Text Available Living organisms respond both to current and previous environments, which can have important consequences on population dynamics. However, there is little experimental evidence based on long-term field studies of the effects of previous environments on the performance of individuals. We tested the hypothesis that trees that establish under different environmental conditions perform differently under similar post-establishment conditions. We used the slow-growing, evergreen Mediterranean oak Quercus ilex subsp. rotundifolia as target species. We analyzed the effects of previous environments, competition effects and tradeoffs among life-history traits (survival, growth, and reproduction. We enhanced seedling establishment for three years by reducing abiotic environmental harshness by means of summer irrigation and artificial shading in 12 experimental plots, while four plots remained as controls. Then these treatments were interrupted for ten years. Seedlings under ameliorated environmental conditions survived and grew faster during early establishment. During the post-management period, previous treatments 1 did not have any effect on survival, 2 experienced a slower above-ground growth, 3 decreased root biomass as indicated from reflectivity of Ground Penetration Radar, 4 increased acorn production mostly through a greater canopy volume and 5 increased acorn production effort. The trees exhibited a combination of effects related to acclimation for coping with abiotic stress and effects of intra-specific competition. In accordance with our hypothesis, tree performance overall depended on previous environmental conditions, and the response was different for different life-history traits. We recommend early management because it increased plot cover, shortened the time to attain sexual maturity and increased the amount of acorn production. Plots such as those assessed in this study may act as sources of propagules in deforested

The link between immunity and life history traits in scleractinian corals

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Jorge H. Pinzón C.

2014-10-01

Full Text Available Immunity is an important biological trait that influences the survival of individuals and the fitness of a species. Immune defenses are costly and likely compete for energy with other life-history traits, such as reproduction and growth, affecting the overall fitness of a species. Competition among these traits in scleractinian corals could influence the dynamics and structural integrity of coral reef communities. Due to variability in biological traits within populations and across species, it is likely that coral colonies within population/species adjust their immune system to the available resources. In corals, the innate immune system is composed of various pathways. The immune system components can be assessed in the absence (constitutive levels and/or presence of stressors/pathogens (immune response. Comparisons of the constitutive levels of three immune pathways (melanin synthesis, antioxidant and antimicrobial of closely related species of Scleractinian corals allowed to determine the link between immunity and reproduction and colony growth. First, we explored differences in constitutive immunity among closely related coral species of the genus Meandrina with different reproductive patterns (gonochoric vs. hermaphrodite. We then compared fast-growing branching vs. slow-growing massive Porites to test co-variation between constitutive immunity and growth rates and morphology in corals. Results indicate that there seems to be a relationship between constitutive immunity and sexual pattern with gonochoric species showing significantly higher levels of immunity than hermaphrodites. Therefore, gonochoric species maybe better suited to resist infections and overcome stressors. Constitutive immunity varied in relation with growth rates and colony morphology, but each species showed contrasting trends within the studied immune pathways. Fast-growing branching species appear to invest more in relatively low cost pathways of the immune system than

Evidence for an age-dependent influence of environmental variations on a long-lived seabird's life-history traits.

Science.gov (United States)

Pardo, Deborah; Barbraud, Christophe; Authier, Matthieu; Weimerskirch, Henri

2013-01-01

Theoretical and empirical studies have highlighted the effects of age on several life-history traits in wild populations. There is also increasing evidence for environmental effects on their demographic traits. However, quantifying how individuals differentially respond to environmental variations according to their age remains a challenge in ecology. In a population of Black-browed Albatrosses monitored during 43 years, we analyzed how life-history traits varied according to age, and whether individuals of different ages responded in different ways to environmental conditions. To do so, we: (1) examined how age affected seven life-history traits, (2) investigated differences in temporal variance of demographic traits between age classes, and (3) tested for age-dependent effects of climate and fisheries covariates on demographic traits. Overall, there was a tendency for traits to improve during the first years of life (5-10 years), to peak and remain stable at middle age (10-30 years), and decline at old ages. At young ages, survival and reproductive parameters increased, except offspring body condition at fledging, suggesting that younger parents had already acquired good foraging capacities. However, they suffered from inexperience in breeding as suggested by their higher breeding failures during incubation. There was evidence for reproductive and actuarial senescence. In particular, breeding success and offspring body condition declined abruptly, suggesting altered foraging capacities of old individuals. Middle-aged individuals had the lowest temporal variance of demographic traits. Although this is predicted by the theory of environmental canalization, it could also results from a higher susceptibility of young and old birds due to their respective inexperience and senescence. The highest temporal variances were found in old individuals. Survival was significantly influenced by sea surface temperatures in the foraging zone of this albatross population during

How Did Host Domestication Modify Life History Traits of Its Pathogens?

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Marie De Gracia

Full Text Available Understanding evolutionary dynamics of pathogens during domestication of their hosts and rise of agro-ecosystems is essential for durable disease management. Here, we investigated changes in life-history traits of the fungal pathogen Venturia inaequalis during domestication of the apple. Life traits linked to fungal dispersal were compared between 60 strains that were sampled in domestic and wild habitats in Kazakhstan, the center of origin of both host and pathogen. Our two main findings are that transition from wild to agro-ecosystems was associated with an increase of both spore size and sporulation capacity; and that distribution of quantitative traits of the domestic population mostly overlapped with those of the wild population. Our results suggest that apple domestication had a considerable impact on fungal characters linked to its dispersal through selection from standing phenotypic diversity. We showed that pestification of V. inaequalis in orchards led to an enhanced allocation in colonization ability from standing variation in the wild area. This study emphasizes the potential threat that pathogenic fungal populations living in wild environments represent for durability of resistance in agro-ecosystems.

Fruit flies may face a nutrient-dependent life-history trade-off between secondary sexual trait quality, survival and developmental rate.

Science.gov (United States)

Gray, Lindsey J; Simpson, Stephen J; Polak, Michal

2018-01-01

Optimal life-history strategies are those that best allocate finite environmental resources to competing traits. We used the geometric framework for nutrition to evaluate life-history strategies followed by Drosophila melanogaster by measuring the condition-dependent performance of life-history traits, including the morphology of male secondary sexual characters, sex combs. We found that depending on their rearing environment flies faced different forms of trait trade-offs and accordingly followed different life-history strategies. High-energy, high-carbohydrate, low-protein diets supported development of the largest and most symmetrical sex combs, however, consistent with handicap models of sexual selection these foods were associated with reduced fly survival and developmental rate. Expressing the highest quality sex combs may have required secondary sexual trait quality to be traded-off with developmental rate, and our results indicated that flies unable to slow development died. As larval nutritional environments are predominantly determined by female oviposition substrate choice, we tested where mated female flies laid the most eggs. Mothers chose high-energy, high-protein foods associated with rapid larval development. Mothers avoided high-carbohydrate foods associated with maximal sex comb expression, showing they may avoid producing fewer 'sexy' sons in favour of producing offspring that develop rapidly. Copyright © 2017 Elsevier Ltd. All rights reserved.

Environmental drivers defining linkages among life-history traits: mechanistic insights from a semiterrestrial amphipod subjected to macroscale gradients.

Science.gov (United States)

Gómez, Julio; Barboza, Francisco R; Defeo, Omar

2013-10-01

Determining the existence of interconnected responses among life-history traits and identifying underlying environmental drivers are recognized as key goals for understanding the basis of phenotypic variability. We studied potentially interconnected responses among senescence, fecundity, embryos size, weight of brooding females, size at maturity and sex ratio in a semiterrestrial amphipod affected by macroscale gradients in beach morphodynamics and salinity. To this end, multiple modelling processes based on generalized additive mixed models were used to deal with the spatio-temporal structure of the data obtained at 10 beaches during 22 months. Salinity was the only nexus among life-history traits, suggesting that this physiological stressor influences the energy balance of organisms. Different salinity scenarios determined shifts in the weight of brooding females and size at maturity, having consequences in the number and size of embryos which in turn affected sex determination and sex ratio at the population level. Our work highlights the importance of analysing field data to find the variables and potential mechanisms that define concerted responses among traits, therefore defining life-history strategies.

Science literacy and natural history museums

Indian Academy of Sciences (India)

2010-10-15

Oct 15, 2010 ... Paradoxically, this is probably the period in the history of advanced countries in which increasing public and personal efforts have been directed toward the dissemination of scientific knowledge to increase public understanding of science. This article vindicates the role of natural history museums in ...

Natural mortality: Its ecology, how it shapes fish life histories, and why it may be increased by fishing

Science.gov (United States)

Jørgensen, Christian; Holt, Rebecca E.

2013-01-01

A stronger focus on natural mortality may be required to better understand contemporary changes in fish life histories and behaviour and their responses to anthropogenic drivers. Firstly, natural mortality is the selection under which fish evolved in the first place, so a theoretical understanding of effects of natural mortality alone is needed. Secondly, due to trade-offs, most organismal functions can only be achieved at some cost in terms of survival. Several trade-offs might need to be analysed simultaneously with effects on natural mortality being a common currency. Thirdly, there is scattered evidence that natural mortality has been increasing, some would say dramatically, in some fished stocks, which begs explanations. Fourthly, natural mortality most often implies transfer of mass and energy from one species to another, and therefore has foodweb and ecosystem consequences. We therefore analyse a model for evolution of fish life histories and behaviour, where state-dependent energy-allocation and growth strategies are found by optimization. Natural mortality is split into five different components, each specified as the outcome of individual traits and ecological trade-offs: a fixed baseline mortality; size-dependent predation; risk-dependent growth strategy; a fixed mortality when sexually mature; and mortality increasing with reproductive investment. The analysis is repeated with and without fishing. Each component of natural mortality has consequences for optimal life history strategies. Beyond earlier models, we show i) how the two types of reproductive mortality sometimes have similar and sometimes contrasting effects on life history evolution, ii) how ecosystem properties such as food availability and predation levels have stronger effects on optimal strategies than changing other mortality components, and iii) how expected changes in risk-dependent growth strategies are highly variable depending on the type of mortality changed.

Early modern natural history: Contributions from the Americas

Indian Academy of Sciences (India)

Early modern natural history: Contributions from the Americas and India. Rajesh Kochhar. Perspectives Volume 37 Issue ... Keywords. India; medical botany; natural history; scientific botany; the Americas. Author Affiliations. Rajesh Kochhar1. Indian Institute of Science Education and Research, Mohali 140 306 Punjab, India ...

Seascape and life-history traits do not predict self-recruitment in a coral reef fish

KAUST Repository

Herrera Sarrias, Marcela; Nanninga, Gerrit B.; Planes, Serge; Jones, Geoffrey P.; Thorrold, Simon R.; Saenz Agudelo, Pablo; Almany, Glenn R.; Berumen, Michael L.

2016-01-01

pairs were sampled from separate reefs. Integrating our findings with earlier research from the same system suggests that geographical setting and life-history traits alone are not suitable predictors of SR and that high levels of localized recruitment

Natural history of COPD

DEFF Research Database (Denmark)

Vestbo, Jørgen; Lange, Peter

2016-01-01

The natural history of chronic obstructive pulmonary disease (COPD) is usually described with a focus on change in forced expiratory volume in 1 s (FEV1 ) over time as this allows for exploration of risk factors for an accelerated decline-and thus of developing COPD. From epidemiological studies we...

Genetic and phenotypic relationships between immune defense, melanism and life-history traits at different temperatures and sexes in Tenebrio molitor.

Science.gov (United States)

Prokkola, J; Roff, D; Kärkkäinen, T; Krams, I; Rantala, M J

2013-08-01

Insect cuticle melanism is linked to a number of life-history traits, and a positive relationship is hypothesized between melanism and the strength of immune defense. In this study, the phenotypic and genetic relationships between cuticular melanization, innate immune defense, individual development time and body size were studied in the mealworm beetle (Tenebrio molitor) using three different temperatures with a half-sib breeding design. Both innate immune defense and cuticle darkness were higher in females than males, and a positive correlation between the traits was found at the lowest temperature. The effect of temperature on all the measured traits was strong, with encapsulation ability and development time decreasing and cuticle darkness increasing with a rise in temperature, and body size showing a curved response. The analysis showed a highly integrated system sensitive to environmental change involving physiological, morphological and life-history traits.

What shall I do now? State-dependent variations of life-history traits with aging in Wandering Albatrosses.

Science.gov (United States)

Pardo, Deborah; Barbraud, Christophe; Weimerskirch, Henri

2014-02-01

Allocation decisions depend on an organism's condition which can change with age. Two opposite changes in life-history traits are predicted in the presence of senescence: either an increase in breeding performance in late age associated with terminal investment or a decrease due to either life-history trade-offs between current breeding and future survival or decreased efficiency at old age. Age variation in several life-history traits has been detected in a number of species, and demographic performances of individuals in a given year are influenced by their reproductive state the previous year. Few studies have, however, examined state-dependent variation in life-history traits with aging, and they focused mainly on a dichotomy of successful versus failed breeding and non-breeding birds. Using a 50-year dataset on the long-lived quasi-biennial breeding wandering albatross, we investigated variations in life-history traits with aging according to a gradient of states corresponding to potential costs of reproduction the previous year (in ascending order): non-breeding birds staying at sea or present at breeding grounds, breeding birds that failed early, late or were successful. We used multistate models to study survival and decompose reproduction into four components (probabilities of return, breeding, hatching, and fledging), while accounting for imperfect detection. Our results suggest the possible existence of two strategies in the population: strict biennial breeders that exhibited almost no reproductive senescence and quasi-biennial breeders that showed an increased breeding frequency with a strong and moderate senescence on hatching and fledging probabilities, respectively. The patterns observed on survival were contrary to our predictions, suggesting an influence of individual quality rather than trade-offs between reproduction and survival at late ages. This work represents a step further into understanding the evolutionary ecology of senescence and its

The Ecological Dynamics of Natural Selection: Traits and the Coevolution of Community Structure.

Science.gov (United States)

McPeek, Mark A

2017-05-01

Natural selection has both genetic and ecological dynamics. The fitnesses of individuals change with their ecological context, and so the form and strength of selective agents change with abiotic factors and the phenotypes and abundances of interacting species. I use standard models of consumer-resource interactions to explore the ecological dynamics of natural selection and how various trait types influence these dynamics and the resulting structure of a community of coevolving species. Evolutionary optima favored by natural selection depend critically on the abundances of interacting species, and the traits of species can undergo dynamic cycling in limited areas of parameter space. The ecological dynamics of natural selection can also drive shifts from one adaptive peak to another, and these ecologically driven adaptive peak shifts are fundamental to the dynamics of niche differentiation. Moreover, this ecological differentiation is fostered in more productive and more benign environments where species interactions are stronger and where the selection gradients generated by species interactions are stronger. Finally, community structure resulting from coevolution depends fundamentally on the types of traits that underlie species interactions. The ecological dynamics of the process cannot be simplified, neglected, or ignored if we are to build a predictive theory of natural selection.

Making "Nature" the history of a scientific journal

CERN Document Server

Baldwin, Melinda

2015-01-01

Making "Nature" is the first book to chronicle the foundation and development of Nature, one of the world's most influential scientific institutions. Now nearing its hundred and fiftieth year of publication, Nature is the international benchmark for scientific publication. Its contributors include Charles Darwin, Ernest Rutherford, and Stephen Hawking, and it has published many of the most important discoveries in the history of science, including articles on the structure of DNA, the discovery of the neutron, the first cloning of a mammal, and the human genome. But how did Nature become such an essential institution? In Making "Nature," Melinda Baldwin charts the rich history of this extraordinary publication from its foundation in 1869 to current debates about online publishing and open access. This pioneering study not only tells Nature's story but also sheds light on much larger questions about the history of science publishing, changes in scientific communication, and shifting notions of "scientific comm...

Natural knowledge as a propaedeutic to self-betterment: Francis Bacon and the transformation of natural history.

Science.gov (United States)

Lancaster, James A T

2012-01-01

This paper establishes the 'emblematic' use of natural history as a propaedeutic to self-betterment in the Renaissance; in particular, in the natural histories of Gessner and Topsell, but also in the works of Erasmus and Rabelais. Subsequently, it investigates how Francis Bacon's conception of natural history is envisaged in relation to them. The paper contends that, where humanist natural historians understood the use of natural knowledge as a preliminary to individual improvement, Bacon conceived self-betterment foremost as a means to Christian charity, or social-betterment. It thus examines the transformation of the moralizing aspect of Renaissance natural history in Bacon's conception of his Great Instauration.

Genetic tools link long-term demographic and life-history traits of anemonefish to their anemone hosts

KAUST Repository

Salles, Océ ane C.; Saenz-Agudelo, Pablo; Almany, Glenn R.; Berumen, Michael L.; Thorrold, Simon R.; Jones, Geoffrey P.; Planes, Serge

2016-01-01

The life-history traits and population dynamics of species are increasingly being attributed to the characteristics of their preferred habitats. While coral reef fish are often strongly associated with particular habitats, long-term studies

Relating life-history traits, environmental constraints and local extinctions in river fish

OpenAIRE

Bergerot, B.; Hugueny, Bernard; Belliard, J.

2015-01-01

The life histories of freshwater fish are widely studied because they represent fundamental determinants of population performances. However, a gap remains in our understanding of how species traits may predispose species to extinction in a changing environment. In this study, based on a large data set provided by the French National Agency for Water and Aquatic Environment (325 sites), we analysed factors that explain the probability of local extinction in 40 freshwater species across French...

The Natural History of Insomnia: Acute Insomnia and First-onset Depression

Science.gov (United States)

Ellis, Jason G.; Perlis, Michael L.; Bastien, Célyne H.; Gardani, Maria; Espie, Colin A.

2014-01-01

Study Objectives: While many studies have examined the association between insomnia and depression, no studies have evaluated these associations (1) within a narrow time frame, (2) with specific reference to acute and chronic insomnia, and (3) using polysomnography. In the present study, the association between insomnia and first-onset depression was evaluated taking into account these considerations. Design: A mixed-model inception design. Setting: Academic research laboratory. Participants: Fifty-four individuals (acute insomnia [n = 33], normal sleepers [n = 21]) with no reported history of a sleep disorder, chronic medical condition, or psychiatric illness. Interventions: N/A. Measurements and Results: Participants were assessed at baseline (2 nights of polysomnography and psychometric measures of stress and mood) and insomnia and depression status were reassessed at 3 months. Individuals with acute insomnia exhibited more stress, poorer mood, worse subjective sleep continuity, increased N2 sleep, and decreased N3 sleep. Individuals who transitioned to chronic insomnia exhibited (at baseline) shorter REM latencies and reduced N3 sleep. Individuals who exhibited this pattern in the transition from acute to chronic insomnia were also more likely to develop first-onset depression (9.26%) as compared to those who remitted from insomnia (1.85%) or were normal sleepers (1.85%). Conclusion: The transition from acute to chronic insomnia is presaged by baseline differences in sleep architecture that have, in the past, been ascribed to Major Depression, either as heritable traits or as acquired traits from prior episodes of depression. The present findings suggest that the “sleep architecture stigmata” of depression may actually develop over the course transitioning from acute to chronic insomnia. Citation: Ellis JG; Perlis ML; Bastien CH; Gardani M; Espie CA. The natural history of insomnia: acute insomnia and first-onset depression. SLEEP 2014;37(1):97-106. PMID

Pollution breaks down the genetic architecture of life history traits in Caenorhabditis elegans.

Directory of Open Access Journals (Sweden)

Morgan Dutilleul

Full Text Available When pollution occurs in an environment, populations present suffer numerous negative and immediate effects on their life history traits. Their evolutionary potential to live in a highly stressful environment will depend on the selection pressure strengths and on the genetic structure, the trait heritability, and the genetic correlations between them. If expression of this structure changes in a stressful environment, it becomes necessary to quantify these changes to estimate the evolutionary potential of the population in this new environment. We studied the genetic structure for survival, fecundity, and early and late growth in isogenic lines of a Caenorhabditis elegans population subject to three different environments: a control environment, an environment polluted with uranium, and a high salt concentration environment. We found a heritability decrease in the polluted environments for fecundity and early growth, two traits that were the most heritable in the control environment. The genetic structure of the traits was particularly affected in the uranium polluted environment, probably due to generally low heritability in this environment. This could prevent selection from acting on traits despite the strong selection pressures exerted on them. Moreover, phenotypic traits were more strongly affected in the salt than in the uranium environment and the heritabilities were also lower in the latter environment. Consequently the decrease in heritability was not proportional to the population fitness reduction in the polluted environments. Our results suggest that pollution can alter the genetic structure of a C. elegans population, and thus modify its evolutionary potential.

Within- and Trans-Generational Effects of Variation in Dietary Macronutrient Content on Life-History Traits in the Moth Plodia interpunctella

Science.gov (United States)

Knell, Robert J.

2016-01-01

It is increasingly clear that parental environment can play an important role in determining offspring phenotype. These “transgenerational effects” have been linked to many different components of the environment, including toxin exposure, infection with pathogens and parasites, temperature and food quality. In this study, we focus on the latter, asking how variation in the quantity and quality of nutrition affects future generations. Previous studies have shown that artificial diets are a useful tool to examine the within-generation effects of variation in macronutrient content on life history traits, and could therefore be applied to investigations of the transgenerational effects of parental diet. Synthetic diets varying in total macronutrient content and protein: carbohydrate ratios were used to examine both within- and trans-generational effects on life history traits in a generalist stored product pest, the Indian meal moth Plodia interpunctella. The macronutrient composition of the diet was important for shaping within-generation life history traits, including pupal weight, adult weight, and phenoloxidase activity, and had indirect effects via maternal weight on fecundity. Despite these clear within-generation effects on the biology of P. interpunctella, diet composition had no transgenerational effects on the life history traits of offspring. P. interpunctella mothers were able to maintain their offspring quality, possibly at the expense of their own somatic condition, despite high variation in dietary macronutrient composition. This has important implications for the plastic biology of this successful generalist pest. PMID:28033396

Within- and Trans-Generational Effects of Variation in Dietary Macronutrient Content on Life-History Traits in the Moth Plodia interpunctella.

Directory of Open Access Journals (Sweden)

Joanne E Littlefair

Full Text Available It is increasingly clear that parental environment can play an important role in determining offspring phenotype. These "transgenerational effects" have been linked to many different components of the environment, including toxin exposure, infection with pathogens and parasites, temperature and food quality. In this study, we focus on the latter, asking how variation in the quantity and quality of nutrition affects future generations. Previous studies have shown that artificial diets are a useful tool to examine the within-generation effects of variation in macronutrient content on life history traits, and could therefore be applied to investigations of the transgenerational effects of parental diet. Synthetic diets varying in total macronutrient content and protein: carbohydrate ratios were used to examine both within- and trans-generational effects on life history traits in a generalist stored product pest, the Indian meal moth Plodia interpunctella. The macronutrient composition of the diet was important for shaping within-generation life history traits, including pupal weight, adult weight, and phenoloxidase activity, and had indirect effects via maternal weight on fecundity. Despite these clear within-generation effects on the biology of P. interpunctella, diet composition had no transgenerational effects on the life history traits of offspring. P. interpunctella mothers were able to maintain their offspring quality, possibly at the expense of their own somatic condition, despite high variation in dietary macronutrient composition. This has important implications for the plastic biology of this successful generalist pest.

Within- and Trans-Generational Effects of Variation in Dietary Macronutrient Content on Life-History Traits in the Moth Plodia interpunctella.

Science.gov (United States)

Littlefair, Joanne E; Knell, Robert J

2016-01-01

It is increasingly clear that parental environment can play an important role in determining offspring phenotype. These "transgenerational effects" have been linked to many different components of the environment, including toxin exposure, infection with pathogens and parasites, temperature and food quality. In this study, we focus on the latter, asking how variation in the quantity and quality of nutrition affects future generations. Previous studies have shown that artificial diets are a useful tool to examine the within-generation effects of variation in macronutrient content on life history traits, and could therefore be applied to investigations of the transgenerational effects of parental diet. Synthetic diets varying in total macronutrient content and protein: carbohydrate ratios were used to examine both within- and trans-generational effects on life history traits in a generalist stored product pest, the Indian meal moth Plodia interpunctella. The macronutrient composition of the diet was important for shaping within-generation life history traits, including pupal weight, adult weight, and phenoloxidase activity, and had indirect effects via maternal weight on fecundity. Despite these clear within-generation effects on the biology of P. interpunctella, diet composition had no transgenerational effects on the life history traits of offspring. P. interpunctella mothers were able to maintain their offspring quality, possibly at the expense of their own somatic condition, despite high variation in dietary macronutrient composition. This has important implications for the plastic biology of this successful generalist pest.

Differences in life-history and ecological traits between co-occurring Panulirus spiny lobsters (Decapoda, Palinuridae).

Science.gov (United States)

Briones-Fourzán, Patricia

2014-01-01

Coexistence of closely related species may be promoted by niche differentiation or result from interspecific trade-offs in life history and ecological traits that influence relative fitness differences and contribute to competitive inequalities. Although insufficient to prove coexistence, trait comparisons provide a first step to identify functional differences between co-occurring congeneric species in relation to mechanisms of coexistence. Here, a comparative review on life history and ecological traits is presented for two pairs of co-occurring species of spiny lobsters in the genus Panulirus: Panulirusgracilis and Panulirusinflatus from the Eastern Central Pacific region, and Panulirusargus and Panulirusguttatus from the Caribbean region. Panulirusgracilis and Panulirusinflatus have similar larval, postlarval, and adult sizes and a similar diet, but differ in degree of habitat specialization, fecundity, and growth rate. However, little is known on behavioral traits of these two species that may influence their competitive abilities and susceptibility to predators. The more abundant information on Panulirusargus and Panulirusguttatus shows that these two species differ more broadly in degree of habitat specialization, larval, postlarval and adult sizes, diet, fecundity, growth rate, degree of sociality, defense mechanisms, susceptibility to predators, and chemical ecology, suggesting a greater degree of niche differentiation between Panulirusargus and Panulirusguttatus than between Panulirusgracilis and Panulirusinflatus. Whether the substantial niche differentiation and apparent interspecific trade-offs between Panulirusargus and Panulirusguttatus relative to Panulirusgracilis and Panulirusinflatus reflect an earlier divergence of the former pair of species in the evolution of the genus constitutes an intriguing hypothesis. However, whether or not post-divergence evolution of each species pair occurred in sympatry remains uncertain.

Life History Traits, Protein Evolution, and the Nearly Neutral Theory in Amniotes.

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Figuet, Emeric; Nabholz, Benoît; Bonneau, Manon; Mas Carrio, Eduard; Nadachowska-Brzyska, Krystyna; Ellegren, Hans; Galtier, Nicolas

2016-06-01

The nearly neutral theory of molecular evolution predicts that small populations should accumulate deleterious mutations at a faster rate than large populations. The analysis of nonsynonymous (dN) versus synonymous (dS) substitution rates in birds versus mammals, however, has provided contradictory results, questioning the generality of the nearly neutral theory. Here we analyzed the impact of life history traits, taken as proxies of the effective population size, on molecular evolutionary and population genetic processes in amniotes, including the so far neglected reptiles. We report a strong effect of species body mass, longevity, and age of sexual maturity on genome-wide patterns of polymorphism and divergence across the major groups of amniotes, in agreement with the nearly neutral theory. Our results indicate that the rate of protein evolution in amniotes is determined in the first place by the efficiency of purifying selection against deleterious mutations-and this is true of both radical and conservative amino acid changes. Interestingly, the among-species distribution of dN/dS in birds did not follow this general trend: dN/dS was not higher in large, long-lived than in small, short-lived species of birds. We show that this unexpected pattern is not due to a more narrow range of life history traits, a lack of correlation between traits and Ne, or a peculiar distribution of fitness effects of mutations in birds. Our analysis therefore highlights the bird dN/dS ratio as a molecular evolutionary paradox and a challenge for future research. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Epidemiology and natural history of vestibular schwannomas

DEFF Research Database (Denmark)

Stangerup, Sven-Eric; Caye-Thomasen, Per

2012-01-01

This article describes various epidemiologic trends for vestibular schwannomas over the last 35 years, including a brief note on terminology. Additionally, it provides information on the natural history of tumor growth and hearing level following the diagnosis of a vestibular schwannoma. A treatm......This article describes various epidemiologic trends for vestibular schwannomas over the last 35 years, including a brief note on terminology. Additionally, it provides information on the natural history of tumor growth and hearing level following the diagnosis of a vestibular schwannoma...

Masked expression of life-history traits in a highly variable environment

Science.gov (United States)

DeBoer, Jason A.; Fontaine, Joseph J.; Chizinski, Christopher J.; Pope, Kevin L.

2015-01-01

Differing life-history strategies may act as a constraint on reproductive expression that ultimately limits the ability of individual species to respond to changes in the magnitude or frequency of environmental variation, and potentially underlies the variation often inherent in phenotypic and evolved responses to anthropogenic change. Alternatively, if there are environmental cues that predict reproductive potential, differential expression of life-history strategies may represent differences in the adaptive capacity to optimize current reproductive value given variation in environmental conditions. We compared several aspects of walleye Sander vitreus spawning ecology at two reservoirs that differ in environmental variability (i.e., annual water-level fluctuation) to identify the capacity of phenotypic expression and the corresponding association with age. Despite significant differences in female body and liver masses between reservoirs that differ in environmental variability, we found no difference in reproductive investment measured by egg size and fecundity. Walleye in a highly variable environment appear to exhibit reproductive traits more typical of a short-lived life-history strategy, which may be resultant from the interaction of environmental and anthropogenic pressures. This finding emphasizes the need to identify the degree to which life-history expression represents physiological constraints versus ecological optimization, particularly as anthropogenic change continues to alter environmental conditions. 

The Natural History of Femoroacetabular Impingement

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Benjamin D. Kuhns

2015-11-01

Full Text Available Femoroacetabular impingement (FAI is a clinical syndrome resulting from abnormal hip joint morphology and is a common cause of hip pain in young adults. FAI has been posited as a precursor to hip osteoarthritis, however, conflicting evidence exists and the true natural history of the disease is unclear. The purpose of this article is to review the current understanding of how FAI damages the hip joint by highlighting its pathomechanics and etiology. We then review the current evidence relating FAI to osteoarthritis. Lastly, we will discuss the potential of hip preservation surgery to alter the natural history of FAI, reduce the risk of developing osteoarthritis and the need for future arthroplasty.

Narrative and natural history in the eighteenth century.

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Terrall, Mary

2017-04-01

In the eighteenth century, natural histories of animals incorporated narratives about animal behaviour and narratives of discovery and experimentation. Naturalists used first-person accounts to link the stories of their scientific investigations to the stories of the animal lives they were studying. Understanding nature depended on narratives that shifted back and forth in any given text between animal and human, and between individual cases and generalizations about species. This paper explores the uses of narrative through examples from the work of René-Antoine Ferchault de Réaumur and Abraham Trembley. In all cases, narrative took the genre of natural history well beyond straightforward description and classification. Prose accounts of insect actions and mechanisms worked in tandem with visual narratives embedded in the accompanying illustrations, where artists developed strategies for representing sequences of minute changes over time. By throwing into relief the narrative sections of natural histories, the examples considered here expose the role played by these tales of encounters with the insect world in the making of natural historical knowledge. Copyright © 2017 Elsevier Ltd. All rights reserved.

Genetic tools link long-term demographic and life-history traits of anemonefish to their anemone hosts

KAUST Repository

Salles, Océane C.

2016-07-26

The life-history traits and population dynamics of species are increasingly being attributed to the characteristics of their preferred habitats. While coral reef fish are often strongly associated with particular habitats, long-term studies establishing the demographic and life-history consequences of occupying different reef substrata are rare and no studies have monitored individuals in situ over their lifetime and determined the fate of their offspring. Here, we documented a quasi-turnover and local reproductive success for an entire population of orange clownfish (Amphiprion percula) from Kimbe Island, Papua New Guinea, by taking bi-annual samples of DNA over a 10-yr period (2003–2013). We compared demographic and life-history traits of individuals living on two host anemone species, Heteractis magnifica and Stichodactyla gigantea, including female size, adult continued presence (a proxy for relative longevity range), early post-settlement growth, the number of eggs per clutch and ‘local’ reproductive success (defined for each adult as the number of offspring returning to the natal population). Our results indicate that while the relative longevity of adults was similar on both host anemone species, females living in H. magnifica were larger than females in S. gigantea. However, despite females growing larger and producing more eggs on H. magnifica, we found that local reproductive success was significantly higher for clownfish living in S. gigantea. Life-history traits also exhibited local spatial variation, with higher local reproductive success recorded for adults living on S. gigantea on the eastern side of the island. Our findings support a ‘silver-spoon’ hypothesis that predicts individuals that are fortunate enough to recruit into good habitat and location will be rewarded with higher long-term reproductive success and will make a disproportionate contribution to population renewal. © 2016 Springer-Verlag Berlin Heidelberg

Effects of germination season on life history traits and on transgenerational plasticity in seed dormancy in a cold desert annual.

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Lu, Juan J; Tan, Dun Y; Baskin, Carol C; Baskin, Jerry M

2016-04-27

The maternal environment can influence the intensity of seed dormancy and thus seasonal germination timing and post-germination life history traits. We tested the hypotheses that germination season influences phenotypic expression of post-germination life history traits in the cold desert annual Isatis violascens and that plants from autumn- and spring-germinating seeds produce different proportions of seeds with nondeep and intermediate physiological dormancy (PD). Seeds were sown in summer and flexibility in various life history traits determined for plants that germinated in autumn and in spring. A higher percentage of spring- than of autumn-germinating plants survived the seedling stage, and all surviving plants reproduced. Number of silicles increased with plant size (autumn- > spring-germinating plants), whereas percent dry mass allocated to reproduction was higher in spring- than in autumn-germinating plants. Autumn-germinating plants produced proportionally more seeds with intermediate PD than spring-germinating plants, while spring-germinating plants produced proportionally more seeds with nondeep PD than autumn-germinating plants. Flexibility throughout the life history and transgenerational plasticity in seed dormancy are adaptations of I. violascens to its desert habitat. Our study is the first to demonstrate that autumn- and spring-germinating plants in a species population differ in proportion of seeds produced with different levels of PD.

Divergent trends in life-history traits between Atlantic salmon Salmo salar of wild and hatchery origin in the Baltic Sea.

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Vainikka, A; Kallio-Nyberg, I; Heino, M; Koljonen, M-L

2010-02-01

Four Atlantic salmon Salmo salar stocks in the Baltic Sea, varying in their breeding history, were studied for changes in life-history traits over the years 1972-1995. Total length (L(T)) at age of captured (L(TC)) fish had increased throughout the study period, partly due to increased temperature and increased L(T) at release, (L(TR)) but also due to remaining cohort effects that could represent unaccounted environmental or genetic change. Simultaneously, maturation probabilities controlled for water temperature, L(TC) and L(TR) had increased in all stocks. The least change was observed in the River Tornionjoki S. salar that was subject only to supportive stockings originating from wild parents. These results suggest a long-term divergence between semi-natural and broodstock-based S. salar stocks. Increased L(T) at age explained advanced maturation only marginally, and it remains an open question to what extent the generally increased probabilities to mature at early age reflected underlying genetic changes.

Natural History: the sense of wonder, creativity and progress in ecology

Directory of Open Access Journals (Sweden)

Paul K. Dayton

2001-12-01

Full Text Available This essay addresses the question of blending natural history and ecological wisdom into the genuine creativity exemplified by Prof. Ramon Margalef. Many have observed that modern biology is a triumph of precision over accuracy, and that ecology has sought maturity by striving toward this model in which the precision value of the tools has supplanted important questions. In pursuing a model of hard science, ecology has struggled with Popperian approaches designed to create a thin patina of real science over the vast seas of uncertainty so admired by the naturalists. We start with a discussion of the importance of natural history in ecology and conservation, and the present state of natural history in academic ecology. We then discuss the respect for natural history in human cultures, and conclude that an infatuation with authority has obfuscated the important truths to be found in nature. We consider some general processes associated with creativity, and finally we ask how natural history influences creativity in ecology. We conclude that the soaring creativity exemplified by Ramon Margalef is based on a joyful almost spiritual understanding of natural history and the courage to avoid authority.

Assembling the dodo in early modern natural history.

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Lawrence, Natalie

2015-09-01

This paper explores the assimilation of the flightless dodo into early modern natural history. The dodo was first described by Dutch sailors landing on Mauritius in 1598, and became extinct in the 1680s or 1690s. Despite this brief period of encounter, the bird was a popular subject in natural-history works and a range of other genres. The dodo will be used here as a counterexample to the historical narratives of taxonomic crisis and abrupt shifts in natural history caused by exotic creatures coming to Europe. Though this bird had a bizarre form, early modern naturalists integrated the dodo and other flightless birds through several levels of conceptual categorization, including the geographical, morphological and symbolic. Naturalists such as Charles L'Ecluse produced a set of typical descriptive tropes that helped make up the European dodo. These long-lived images were used for a variety of symbolic purposes, demonstrated by the depiction of the Dutch East India enterprise in Willem Piso's 1658 publication. The case of the dodo shows that, far from there being a dramatic shift away from emblematics in the seventeenth century, the implicit symbolic roles attributed to exotic beasts by naturalists constructing them from scant information and specimens remained integral to natural history.

Epidemiology and natural history of atopic diseases

DEFF Research Database (Denmark)

Thomsen, Simon F

2015-01-01

The atopic diseases - atopic dermatitis, asthma, and hay fever - pose a great burden to the individual and society, not least, since these diseases have reached epidemic proportions during the past decades in industrialized and, more recently, in developing countries. Whereas the prevalence...... of the atopic diseases now seems to have reached a plateau in many Western countries, they are still on the increase in the developing world. This emphasizes continuing research aimed at identifying the causes, risk factors, and natural history of these diseases. Herein, the fundamental aspects of the natural...... history and epidemiology of the atopic diseases are reviewed....

Leaf and life history traits predict plant growth in a green roof ecosystem.

Directory of Open Access Journals (Sweden)

Jeremy Lundholm

Full Text Available Green roof ecosystems are constructed to provide services such as stormwater retention and urban temperature reductions. Green roofs with shallow growing media represent stressful conditions for plant survival, thus plants that survive and grow are important for maximizing economic and ecological benefits. While field trials are essential for selecting appropriate green roof plants, we wanted to determine whether plant leaf traits could predict changes in abundance (growth to provide a more general framework for plant selection. We quantified leaf traits and derived life-history traits (Grime's C-S-R strategies for 13 species used in a four-year green roof experiment involving five plant life forms. Changes in canopy density in monocultures and mixtures containing one to five life forms were determined and related to plant traits using multiple regression. We expected traits related to stress-tolerance would characterize the species that best grew in this relatively harsh setting. While all species survived to the end of the experiment, canopy species diversity in mixture treatments was usually much lower than originally planted. Most species grew slower in mixture compared to monoculture, suggesting that interspecific competition reduced canopy diversity. Species dominant in mixture treatments tended to be fast-growing ruderals and included both native and non-native species. Specific leaf area was a consistently strong predictor of final biomass and the change in abundance in both monoculture and mixture treatments. Some species in contrasting life-form groups showed compensatory dynamics, suggesting that life-form mixtures can maximize resilience of cover and biomass in the face of environmental fluctuations. This study confirms that plant traits can be used to predict growth performance in green roof ecosystems. While rapid canopy growth is desirable for green roofs, maintenance of species diversity may require engineering of conditions that

Leaf and life history traits predict plant growth in a green roof ecosystem.

Science.gov (United States)

Lundholm, Jeremy; Heim, Amy; Tran, Stephanie; Smith, Tyler

2014-01-01

Green roof ecosystems are constructed to provide services such as stormwater retention and urban temperature reductions. Green roofs with shallow growing media represent stressful conditions for plant survival, thus plants that survive and grow are important for maximizing economic and ecological benefits. While field trials are essential for selecting appropriate green roof plants, we wanted to determine whether plant leaf traits could predict changes in abundance (growth) to provide a more general framework for plant selection. We quantified leaf traits and derived life-history traits (Grime's C-S-R strategies) for 13 species used in a four-year green roof experiment involving five plant life forms. Changes in canopy density in monocultures and mixtures containing one to five life forms were determined and related to plant traits using multiple regression. We expected traits related to stress-tolerance would characterize the species that best grew in this relatively harsh setting. While all species survived to the end of the experiment, canopy species diversity in mixture treatments was usually much lower than originally planted. Most species grew slower in mixture compared to monoculture, suggesting that interspecific competition reduced canopy diversity. Species dominant in mixture treatments tended to be fast-growing ruderals and included both native and non-native species. Specific leaf area was a consistently strong predictor of final biomass and the change in abundance in both monoculture and mixture treatments. Some species in contrasting life-form groups showed compensatory dynamics, suggesting that life-form mixtures can maximize resilience of cover and biomass in the face of environmental fluctuations. This study confirms that plant traits can be used to predict growth performance in green roof ecosystems. While rapid canopy growth is desirable for green roofs, maintenance of species diversity may require engineering of conditions that favor less

Inselect: Automating the Digitization of Natural History Collections.

Directory of Open Access Journals (Sweden)

Lawrence N Hudson

Full Text Available The world's natural history collections constitute an enormous evidence base for scientific research on the natural world. To facilitate these studies and improve access to collections, many organisations are embarking on major programmes of digitization. This requires automated approaches to mass-digitization that support rapid imaging of specimens and associated data capture, in order to process the tens of millions of specimens common to most natural history collections. In this paper we present Inselect-a modular, easy-to-use, cross-platform suite of open-source software tools that supports the semi-automated processing of specimen images generated by natural history digitization programmes. The software is made up of a Windows, Mac OS X, and Linux desktop application, together with command-line tools that are designed for unattended operation on batches of images. Blending image visualisation algorithms that automatically recognise specimens together with workflows to support post-processing tasks such as barcode reading, label transcription and metadata capture, Inselect fills a critical gap to increase the rate of specimen digitization.

Effect of captivity on genetic variance for five traits in the large milkweed bug (Oncopeltus fasciatus).

Science.gov (United States)

Rodríguez-Clark, K M

2004-07-01

Understanding the changes in genetic variance which may occur as populations move from nature into captivity has been considered important when populations in captivity are used as models of wild ones. However, the inherent significance of these changes has not previously been appreciated in a conservation context: are the methods aimed at founding captive populations with gene diversity representative of natural populations likely also to capture representative quantitative genetic variation? Here, I investigate changes in heritability and a less traditional measure, evolvability, between nature and captivity for the large milkweed bug, Oncopeltus fasciatus, to address this question. Founders were collected from a 100-km transect across the north-eastern US, and five traits (wing colour, pronotum colour, wing length, early fecundity and later fecundity) were recorded for founders and for their offspring during two generations in captivity. Analyses reveal significant heritable variation for some life history and morphological traits in both environments, with comparable absolute levels of evolvability across all traits (0-30%). Randomization tests show that while changes in heritability and total phenotypic variance were highly variable, additive genetic variance and evolvability remained stable across the environmental transition in the three morphological traits (changing 1-2% or less), while they declined significantly in the two life-history traits (5-8%). Although it is unclear whether the declines were due to selection or gene-by-environment interactions (or both), such declines do not appear inevitable: captive populations with small numbers of founders may contain substantial amounts of the evolvability found in nature, at least for some traits.

Climate and Human History of Nature

DEFF Research Database (Denmark)

Frølund, Sune

2015-01-01

The paper investigates the ideas that have prevented environmental knowledge from developing into action and change. According to Clarence J. Glacken throughout European history design ideas about the relation between man and nature have prevented the many local observations of the negative...... expose some ecological ideas – that nature itself is a perpetual equilibrium and that man lived in harmony with nature until the emergence of modernity (industrialisation, capitalism, and technology) – as illusions. Such ‘new’ ecological ideas can be seen as disguised versions of the old design idea...

Natural history collections as windows on evolutionary processes.

Science.gov (United States)

Holmes, Michael W; Hammond, Talisin T; Wogan, Guinevere O U; Walsh, Rachel E; LaBarbera, Katie; Wommack, Elizabeth A; Martins, Felipe M; Crawford, Jeremy C; Mack, Katya L; Bloch, Luke M; Nachman, Michael W

2016-02-01

Natural history collections provide an immense record of biodiversity on Earth. These repositories have traditionally been used to address fundamental questions in biogeography, systematics and conservation. However, they also hold the potential for studying evolution directly. While some of the best direct observations of evolution have come from long-term field studies or from experimental studies in the laboratory, natural history collections are providing new insights into evolutionary change in natural populations. By comparing phenotypic and genotypic changes in populations through time, natural history collections provide a window into evolutionary processes. Recent studies utilizing this approach have revealed some dramatic instances of phenotypic change over short timescales in response to presumably strong selective pressures. In some instances, evolutionary change can be paired with environmental change, providing a context for potential selective forces. Moreover, in a few cases, the genetic basis of phenotypic change is well understood, allowing for insight into adaptive change at multiple levels. These kinds of studies open the door to a wide range of previously intractable questions by enabling the study of evolution through time, analogous to experimental studies in the laboratory, but amenable to a diversity of species over longer timescales in natural populations. © 2016 John Wiley & Sons Ltd.

Mortality of Inherited Arrhythmia Syndromes Insight Into Their Natural History

NARCIS (Netherlands)

Nannenberg, Eline A.; Sijbrands, Eric J. G.; Dijksman, Lea M.; Alders, Marielle; van Tintelen, J. Peter; Birnie, Martijn; van Langen, Irene M.; Wilde, Arthur A. M.

Background-For most arrhythmia syndromes, the risk of sudden cardiac death for asymptomatic mutation carriers is ill defined. Data on the natural history of these diseases, therefore, are essential. The family tree mortality ratio method offers the unique possibility to study the natural history at

Is natural history really dead?: Toward the rebirth of natural history ¿Está realmente muerta la historia natural?: Hacia el renacimiento de la Historia Natural

Directory of Open Access Journals (Sweden)

MARY F WILLSON

2006-06-01

Full Text Available In recent years natural history has been derided by some scientists as an old-fashion endeavor that does not follow the model of "hard" science and therefore should be considered "dead" and replaced by modern ecology, evolutionary biology, and conservation biology. We contend that natural history has much to offer to contemporary scientists and that it has a primary role in the creative process of generating novel hypotheses and designing significant field experiments and observationsEn años recientes, la historia natural ha sido desacreditada por científicos que la consideran un modelo obsoleto de ciencia y que, en consecuencia, se trataría de una disciplina "muerta" que ha sido reemplazada por la ecología moderna, la biología evolutiva y la biología de la conservación. Argumentamos aquí que la historia natural tiene mucho que ofrecer a los científicos contemporáneos y que juega un rol principal en el proceso de creación de hipótesis y en el diseño acertado de observaciones y experimentos de campo

How universal are reserve design rules? A test using butterflies and their life history traits

Czech Academy of Sciences Publication Activity Database

Bartoňová, Alena; Beneš, Jiří; Faltýnek Fric, Zdeněk; Chobot, K.; Konvička, Martin

2016-01-01

Roč. 39, č. 5 (2016), s. 456-464 ISSN 0906-7590 R&D Projects: GA ČR GAP505/10/2167 Grant - others:GA JU(CZ) 04-168/2013/P Institutional support: RVO:60077344 Keywords : life history traits * butterflies * heterogeneity Subject RIV: EH - Ecology, Behaviour Impact factor: 4.902, year: 2016 http://onlinelibrary.wiley.com/doi/10.1111/ecog.01642/abstract

Understanding the natural history of Gaucher disease.

Science.gov (United States)

Mistry, Pramod K; Belmatoug, Nadia; vom Dahl, Stephan; Giugliani, Roberto

2015-07-01

Gaucher disease is a rare and extraordinarily heterogeneous inborn error of metabolism that exhibits diverse manifestations, a broad range of age of onset of symptoms, and a wide clinical spectrum of disease severity, from lethal disease during infancy to first age of onset of symptoms in octogenarians. Before the advent of the International Collaborative Gaucher Group (ICGG) Gaucher Registry, the understanding of the natural history and phenotypic range of Gaucher disease was based on isolated case reports and small case series. Limited data hindered understanding of the full spectrum of the disease leading to some early misconceptions about Gaucher disease, notably, that nonneuronopathic (type 1) disease was a disease of adults only. The global scope of the ICGG Gaucher Registry, with its vast body of longitudinal data, has enabled a real appreciation of both the phenotypic spectrum of Gaucher disease and its natural history. This body of evidence represents the foundation for accurate assessment of the response to specific therapies for Gaucher disease and to the development of standard-of-care to monitor disease activity. Here, we outline the key developments in delineating the natural history of this highly complex disease and role of the ICGG Gaucher Registry in this effort. © 2015 Wiley Periodicals, Inc.

More than a Museum: Natural History is Relevant in 21st Century Environmental Science

Science.gov (United States)

Hernandez, R. R.; Murphy-Mariscal, M. L.; Barrows, C. W.

2015-12-01

In the Anthropocene, the relevancy of natural history in environmental science is challenged and marginalized today more than ever. We tested the hypothesis that natural history is relevant to the fields of environmental science and ecology by assessing the values, needs, and decisions related to natural history of graduate students and environmental science professionals across 31 universities and various employers, respectively, in California. Graduate students surveyed (93.3%) agreed that natural history was relevant to science, approximately 70% believed it "essential" for conducting field-based research; however, 54.2% felt inadequately trained to teach a natural history course and would benefit from additional training in natural history (> 80%). Of the 185 professionals surveyed, all felt that natural history was relevant to science and "essential" or "desirable" in their vocation (93%). Our results indicate a disconnect between the value and relevancy of natural history in 21st century ecological science and opportunities for gaining those skills and knowledge through education and training.

Connecting health and natural history: a failed initiative at the American Museum of Natural History, 1909-1922.

Science.gov (United States)

Brown, Julie K

2014-10-01

In 1909, curator Charles-Edward Winslow established a department of public health in New York City's American Museum of Natural History (AMNH). Winslow introduced public health as a biological science that connected human health-the modern sciences of physiology, hygiene, and urban sanitation-to the natural history of plants and animals. This was the only time an American museum created a curatorial department devoted to public health. The AMNH's Department of Public Health comprised a unique collection of live bacterial cultures-a "Living Museum"-and an innovative plan for 15 exhibits on various aspects of health. I show how Winslow, facing opposition from AMNH colleagues, gathered scientific experts and financial support, and explain the factors that made these developments seem desirable and possible. I finish with a discussion of how the Department of Public Health met an abrupt and "inglorious end" in 1922 despite the success of its collections and exhibitions.

Profiling crop pollinators: life history traits predict habitat use and crop visitation by Mediterranean wild bees.

Science.gov (United States)

Pisanty, Gideon; Mandelik, Yael

2015-04-01

Wild pollinators, bees in particular, may greatly contribute to crop pollination and provide a safety net against declines in commercial pollinators. However, the identity, life history traits, and environmental sensitivities of main crop pollinator species.have received limited attention. These are crucial for predicting pollination services of different communities and for developing management practices that enhance crop pollinators. We sampled wild bees in three crop systems (almond, confection sunflower, and seed watermelon) in a mosaic Israeli Mediterranean landscape. Bees were sampled in field/orchard edges and interiors, and in seminatural scrub surrounding the fields/orchards. We also analyzed land cover at 50-2500 m radii around fields/orchards. We used this data to distinguish crop from non-crop pollinators based on a set of life history traits (nesting, lecty, sociality, body size) linked to habitat preference and crop visitation. Bee abundance and species richness decreased from the surrounding seminatural habitat to the field/orchard interior, especially across the seminatural habitat-field edge ecotone. Thus, although rich bee communities were found near fields, only small fractions crossed the ecotone and visited crop flowers in substantial numbers. The bee assemblage in agricultural fields/orchards and on crop flowers was dominated by ground-nesting bees of the tribe Halictini, which tend to nest within fields. Bees' habitat preferences were determined mainly by nesting guild, whereas crop visitation was determined mainly by sociality. Lecty and body size also affected both measures. The percentage of surrounding seminatural habitat at 250-2500 m radii had a positive effect on wild bee diversity in field edges, for all bee guilds, while at 50-100 m radii, only aboveground nesters were positively affected. In sum, we found that crop and non-crop pollinators are distinguished by behavioral and morphological traits. Hence, analysis of life-history

Natural History of HPV and Cervical Cancer

Centers for Disease Control (CDC) Podcasts

Dr. Phil Castle, an intramural research scientist at the National Institutes of Health, talks about the natural history of human papillomavirus (HPV) infections, and cervical cancer and other anogenital cancers.

Intra-specific variability in life-history traits of Anadara tuberculosa (Mollusca: Bivalvia) in the mangrove ecosystem of the Southern coast of Ecuador.

Science.gov (United States)

Flores, Luis; Licandeo, Roberto; Cubillos, Luis A; Mora, Elba

2014-06-01

Anadara tuberculosa is one of the most important bivalves along the Western Pacific coast because of its commercial value. Nevertheless, the variability in growth, long-life span, natural mortality and reproductive parameters of this mangrove cockle has not yet been described. The aim of this study was to analyze these life-history traits in three areas of the Southern coast of Ecuador. Empirical and length-based methods were used to estimate these biological parameters. Body size data were collected from the commercial fishery between 2004 and 2011 in landing ports near to the Archipelago of Jambeli [Puerto Bolivar (PB), Puerto Jeli (PJ) and Puerto Hualtaco (PH)]. The von Bertalanffy growth parameters for combined sex were estimated between 70.87 to 93.45mm for L(infinity) and 0.22 to 0.80/year for k. The growth indices (PHI') ranged from 3.17 to 3.85, while the overall growth performance (OGP) ranged from 5.03 to 5.82. The mean of long-life span (t(max)), size and age at maturity (L50% and t50%) were estimated in 7.71 +/- 2.53 years, 39.13 +/- 2.24mm and 1.46 +/- 0.56 years for PB; 9.51 +/- 2.85 years, 37.78 +/- 1.95mm and 1.37 +/- 0.41 years for PJ and 5.81 +/- 2.11 years, 39.73 +/- 3.31mm and 0.94 +/- 0.41 years for PH. Natural mortality (M) ranged from 0.46 to 1.28/year. We concluded that significant intra-specific variation was observed in a temporal scale in PHI' and OGP indices as well as L50% and M. Therefore, temporal changes in these life-history traits should be taken into account when assessing the status of the mangrove cockle fishery.

Natural history collections: A scientific treasure trove

Science.gov (United States)

,

2006-01-01

Natural history collections play an indispensable and often overlooked role in the conservation and management of our Nation’s flora and fauna. Scientific specimens housed in museum collections not only open an important window into the current and past diversity of life on Earth, but also play a vital role in fueling cutting-edge scientific research in many disciplines. The U.S. Geological Survey (USGS) Fort Collins Science Center (FORT) curates a collection of vertebrates from the Intermountain and Southwestern United States that is used by researchers from around the globe. As one of the largest Federal natural history collections in the western United States, the USGS specimen holdings offer unique opportunities to study the fauna of this incredibly diverse and unique region.

Clustering of PCOS-like traits in naturally hyperandrogenic female rhesus monkeys.

Science.gov (United States)

Abbott, D H; Rayome, B H; Dumesic, D A; Lewis, K C; Edwards, A K; Wallen, K; Wilson, M E; Appt, S E; Levine, J E

2017-04-01

Do naturally occurring, hyperandrogenic (≥1 SD of population mean testosterone, T) female rhesus monkeys exhibit traits typical of women with polycystic ovary syndrome (PCOS)? Hyperandrogenic female monkeys exhibited significantly increased serum levels of androstenedione (A4), 17-hydroxyprogesterone (17-OHP), estradiol (E2), LH, antimullerian hormone (AMH), cortisol, 11-deoxycortisol and corticosterone, as well as increased uterine endometrial thickness and evidence of reduced fertility, all traits associated with PCOS. Progress in treating women with PCOS is limited by incomplete knowledge of its pathogenesis and the absence of naturally occurring PCOS in animal models. A female macaque monkey, however, with naturally occurring hyperandrogenism, anovulation and polyfollicular ovaries, accompanied by insulin resistance, increased adiposity and endometrial hyperplasia, suggests naturally occurring origins for PCOS in nonhuman primates. As part of a larger study, circulating serum concentrations of selected pituitary, ovarian and adrenal hormones, together with fasted insulin and glucose levels, were determined in a single, morning blood sample obtained from 120 apparently healthy, ovary-intact, adult female rhesus monkeys (Macaca mulatta) while not pregnant or nursing. The monkeys were then sedated for somatometric and ultrasonographic measurements. Female monkeys were of prime reproductive age (7.2 ± 0.1 years, mean ± SEM) and represented a typical spectrum of adult body weight (7.4 ± 0.2 kg; maximum 12.5, minimum 4.6 kg). Females were defined as having normal (n = 99) or high T levels (n = 21; ≥1 SD above the overall mean, 0.31 ng/ml). Electronic health records provided menstrual and fecundity histories. Steroid hormones were determined by tandem LC-MS-MS; AMH was measured by enzymeimmunoassay; LH, FSH and insulin were determined by radioimmunoassay; and glucose was read by glucose meter. Most analyses were limited to 80 females (60 normal T, 20 high T) in

Are most samples of animals systematically biased? Consistent individual trait differences bias samples despite random sampling.

Science.gov (United States)

Biro, Peter A

2013-02-01

Sampling animals from the wild for study is something nearly every biologist has done, but despite our best efforts to obtain random samples of animals, 'hidden' trait biases may still exist. For example, consistent behavioral traits can affect trappability/catchability, independent of obvious factors such as size and gender, and these traits are often correlated with other repeatable physiological and/or life history traits. If so, systematic sampling bias may exist for any of these traits. The extent to which this is a problem, of course, depends on the magnitude of bias, which is presently unknown because the underlying trait distributions in populations are usually unknown, or unknowable. Indeed, our present knowledge about sampling bias comes from samples (not complete population censuses), which can possess bias to begin with. I had the unique opportunity to create naturalized populations of fish by seeding each of four small fishless lakes with equal densities of slow-, intermediate-, and fast-growing fish. Using sampling methods that are not size-selective, I observed that fast-growing fish were up to two-times more likely to be sampled than slower-growing fish. This indicates substantial and systematic bias with respect to an important life history trait (growth rate). If correlations between behavioral, physiological and life-history traits are as widespread as the literature suggests, then many animal samples may be systematically biased with respect to these traits (e.g., when collecting animals for laboratory use), and affect our inferences about population structure and abundance. I conclude with a discussion on ways to minimize sampling bias for particular physiological/behavioral/life-history types within animal populations.

Life History Traits Reflect Changes in Mediterranean Butterfly Communities Due to Forest Encroachment.

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Jana Slancarova

Full Text Available The biodiversity of the Southern Balkans, part of the Mediterranean global biodiversity hot-spot, is threatened by land use intensification and abandonment, the latter causing forest encroachment of formerly open habitats. We investigated the impact of forest encroachment on butterfly species richness, community species composition and the representation of life history traits by repeated seasonal visits of 150 one-hectare sites in five separate regions in three countries-Greece, Bulgaria, and the Republic of Macedonia (FYROM-the Former Yugoslav Republic of Macedonia- 10 replicates for each habitat type of grasslands, open formations and scrub forest within each region. Grasslands and open formations sites hosted in average more species and more red-listed species than scrub forest, while no pattern was found for numbers of Mediterranean species. As shown by ordination analyses, each of the three habitat types hosted distinct butterfly communities, with Mediterranean species inclining either towards grasslands or open formations. Analysing the representation of life history traits revealed that successional development from grasslands and open formations towards scrub forest shifts the community composition towards species overwintering in earlier stages, having fewer generations per year, and inhabiting large European or Eurosiberian (e.g. northern ranges; it decreases the representation of Mediterranean endemics. The loss of grasslands and semi-open formations due to forest encroachment thus threatens exactly the species that should be the focus of conservation attention in the Mediterranean region, and innovative conservation actions to prevent ongoing forest encroachment are badly needed.

Linking climate change to community-level impacts on copepods via a new, trait-based model: Life-history and metabolic mechanisms compared

DEFF Research Database (Denmark)

Banas, Neil S.; Møller, Eva Friis; Nielsen, Torkel Gissel

2017-01-01

A new, trait-based copepod model ("Coltrane": Copepod Life-history Traits and Adaptation to Novel Environments) has been developed, drawing on past work on both optimal annual routines and trait-based plankton metacommunity models, in order to evaluate climate impacts on copepods via 1) phenology...... and physiology of local populations of C. finmarchicus, C. glacialis, and C. hyperboreus. Futhermore, the model replicates the observed range of stored lipid content of these copepod populations (30–60%, C. finmarchicus–C. hyperboreus), suggesting a means for linking changes in temperature and primary production...

Linking climate change to community-level impacts on copepods via a new, trait-based model: Life-history and metabolic mechanisms compared

DEFF Research Database (Denmark)

Banas, Neil S.; Møller, Eva Friis; Nielsen, Torkel Gissel

A new, trait-based copepod model ("Coltrane": Copepod Life-history Traits and Adaptation to Novel Environments) has been developed, drawing on past work on both optimal annual routines and trait-based plankton metacommunity models, in order to evaluate climate impacts on copepods via 1) phenology...... and physiology of local populations of C. finmarchicus, C. glacialis, and C. hyperboreus. Futhermore, the model replicates the observed range of stored lipid content of these copepod populations (30–60%, C. finmarchicus–C. hyperboreus), suggesting a means for linking changes in temperature and primary production...

Effects of 4-nonylphenol, fish predation and food availability on survival and life history traits of Daphnia magna straus.

Science.gov (United States)

Beklioglu, Meryem; Banu Akkas, S; Elif Ozcan, H; Bezirci, Gizem; Togan, Inci

2010-06-01

This study aimed to investigate the compound effect of environmentally relevant 4-nonylphenol (NP) concentrations and natural stressors-namely fish predation and food availability-on Daphnia magna, which were exposed to four NP concentrations (0, 1, 5 and 10 microg l(-1)) under optimum or low food concentrations (1.00 and 0.075 mg C l(-1), respectively) in water (un)conditioned by a fish predator (Alburnus alburnus). A(n) "environmentally relevant" and "no observable effect" concentration (NOEC) of NP (10 microg l(-1)) resulted in a significant reduction (P ecosystems. The deterioration of the life-history traits-namely, NP-induced delay in the age at first reproduction (P ecosystems. The results of this study demonstrate the importance of taking into account environmentally realistic conditions while investigating the effects of NOEC levels of toxicants on non-target aquatic species.

Trait differences between naturalized and invasive plant species independent of residence time and phylogeny.

Science.gov (United States)

Gallagher, R V; Randall, R P; Leishman, M R

2015-04-01

The ability to predict which alien plants will transition from naturalized to invasive prior to their introduction to novel regions is a key goal for conservation and has the potential to increase the efficacy of weed risk assessment (WRA). However, multiple factors contribute to plant invasion success (e.g., functional traits, range characteristics, residence time, phylogeny), and they all must be taken into account simultaneously in order to identify meaningful correlates of invasion success. We compiled 146 pairs of phylogenetically paired (congeneric) naturalized and invasive plant species in Australia with similar minimum residence times (i.e., time since introduction in years). These pairs were used to test for differences in 5 functional traits (flowering duration, leaf size, maximum height, specific leaf area [SLA], seed mass) and 3 characteristics of species' native ranges (biome occupancy, mean annual temperature, and rainfall breadth) between naturalized and invasive species. Invasive species, on average, had larger SLA, longer flowering periods, and were taller than their congeneric naturalized relatives. Invaders also exhibited greater tolerance for different environmental conditions in the native range, where they occupied more biomes and a wider breadth of rainfall and temperature conditions than naturalized congeners. However, neither seed mass nor leaf size differed between pairs of naturalized and invasive species. A key finding was the role of SLA in distinguishing between naturalized and invasive pairs. Species with high SLA values were typically associated with faster growth rates, more rapid turnover of leaf material, and shorter lifespans than those species with low SLA. This suite of characteristics may contribute to the ability of a species to transition from naturalized to invasive across a wide range of environmental contexts and disturbance regimes. Our findings will help in the refinement of WRA protocols, and we advocate the inclusion

Macroevolution of panicoid inflorescences: a history of contingency and order of trait acquisition

Science.gov (United States)

Reinheimer, R.; Vegetti, A. C.; Rua, G. H.

2013-01-01

inflorescence traits with plant longevity and photosynthetic type is not confirmed. Conclusions The findings indicate that the lability of the panicoid inflorescence is apparent, not real. The results indicate that the history of the panicoids inflorescence is a combination of inflorescence trait contingency and order of character acquisition. These indicate that developmental and genetic mechanisms may be important constraints that have limited the diversification of the inflorescence form in panicoid grasses. PMID:23478945

Historia and materia: the philosophical implications of Francis Bacon's natural history.

Science.gov (United States)

Giglioni, Guido

2012-01-01

This article examines the philosophical implications underlying Bacon's views on historical knowledge, paying special attention to that variety of historical knowledge described by Bacon as "natural." More specifically, this article explores the interplay of history (historia) and fable (fabula). In the sphere of thought, fabula is the equivalent to materia in nature. Both are described by Bacon as being "versatile" and "pliant." In Bacon's system of knowledge, philosophy, as the domain of reason, starts from historiae and fabulae, once memory and the imagination have fulfilled their cognitive tasks. This means that, for Bacon, there is no such thing as a pure use of reason. He advocates a kind of reason that, precisely because it is involved with matter's inner motions (its "appetites," in Bacon's characteristic language), is constitutively 'impure'. The article shows how the terms historia and fabula cover key semantic areas in defining Bacon's philosophy: historia may mean "history" as well as "story,"fabula "myth" as well "story". In both cases, we can see significant oscillations from a stronger meaning (close to those of matter and nature) to a weaker one (connected to wit and imagination), as if the power of nature decreases moving from histories and myths to stories. On the other hand, there are cases in which Bacon seems to stick to a diachronic view of the meaning of fables and histories, such that the transition from myths to history, especially natural history, is described as a collective effort towards reality and enlightenment.

The Natural Science Underlying Big History

Directory of Open Access Journals (Sweden)

Eric J. Chaisson

2014-01-01

Full Text Available Nature’s many varied complex systems—including galaxies, stars, planets, life, and society—are islands of order within the increasingly disordered Universe. All organized systems are subject to physical, biological, or cultural evolution, which together comprise the grander interdisciplinary subject of cosmic evolution. A wealth of observational data supports the hypothesis that increasingly complex systems evolve unceasingly, uncaringly, and unpredictably from big bang to humankind. These are global history greatly extended, big history with a scientific basis, and natural history broadly portrayed across ∼14 billion years of time. Human beings and our cultural inventions are not special, unique, or apart from Nature; rather, we are an integral part of a universal evolutionary process connecting all such complex systems throughout space and time. Such evolution writ large has significant potential to unify the natural sciences into a holistic understanding of who we are and whence we came. No new science (beyond frontier, nonequilibrium thermodynamics is needed to describe cosmic evolution’s major milestones at a deep and empirical level. Quantitative models and experimental tests imply that a remarkable simplicity underlies the emergence and growth of complexity for a wide spectrum of known and diverse systems. Energy is a principal facilitator of the rising complexity of ordered systems within the expanding Universe; energy flows are as central to life and society as they are to stars and galaxies. In particular, energy rate density—contrasting with information content or entropy production—is an objective metric suitable to gauge relative degrees of complexity among a hierarchy of widely assorted systems observed throughout the material Universe. Operationally, those systems capable of utilizing optimum amounts of energy tend to survive, and those that cannot are nonrandomly eliminated.

Ecology of Floristic Quality Assessment: testing for correlations between coefficients of conservatism, species traits and mycorrhizal responsiveness.

Science.gov (United States)

Bauer, Jonathan T; Koziol, Liz; Bever, James D

2018-02-01

Many plant species are limited to habitats relatively unaffected by anthropogenic disturbance, so protecting these undisturbed habitats is essential for plant conservation. Coefficients of conservatism (C values) were developed as indicators of a species' sensitivity to anthropogenic disturbance, and these values are used in Floristic Quality Assessment as a means of assessing natural areas and ecological restoration. However, assigning of these values is subjective and improved quantitative validation of C values is needed. We tested whether there are consistent differences in life histories between species with high and low C values. To do this, we grew 54 species of tallgrass prairie plants in a greenhouse and measured traits that are associated with trade-offs on the fast-slow continuum of life-history strategies. We also grew plants with and without mycorrhizal fungi as a test of these species' reliance on this mutualism. We compared these traits and mycorrhizal responsiveness to C values. We found that six of the nine traits we measured were correlated with C values, and together, traits predicted up to 50 % of the variation in C values. Traits including fast growth rates and greater investment in reproduction were associated with lower C values, and slow growth rates, long-lived leaves and high root:shoot ratios were associated with higher C values. Additionally, plants with high C values and a slow life history were more responsive to mutualisms with mycorrhizal fungi. Overall, our results connect C values with life-history trade-offs, indicating that high C value species tend to share a suite of traits associated with a slow life history.

Neutral mutation as the source of genetic variation in life history traits.

Science.gov (United States)

Brcić-Kostić, Krunoslav

2005-08-01

The mechanism underlying the maintenance of adaptive genetic variation is a long-standing question in evolutionary genetics. There are two concepts (mutation-selection balance and balancing selection) which are based on the phenotypic differences between alleles. Mutation - selection balance and balancing selection cannot properly explain the process of gene substitution, i.e. the molecular evolution of quantitative trait loci affecting fitness. I assume that such loci have non-essential functions (small effects on fitness), and that they have the potential to evolve into new functions and acquire new adaptations. Here I show that a high amount of neutral polymorphism at these loci can exist in real populations. Consistent with this, I propose a hypothesis for the maintenance of genetic variation in life history traits which can be efficient for the fixation of alleles with very small selective advantage. The hypothesis is based on neutral polymorphism at quantitative trait loci and both neutral and adaptive gene substitutions. The model of neutral - adaptive conversion (NAC) assumes that neutral alleles are not neutral indefinitely, and that in specific and very rare situations phenotypic (relative fitness) differences between them can appear. In this paper I focus on NAC due to phenotypic plasticity of neutral alleles. The important evolutionary consequence of NAC could be the increased adaptive potential of a population. Loci responsible for adaptation should be fast evolving genes with minimally discernible phenotypic effects, and the recent discovery of genes with such characteristics implicates them as suitable candidates for loci involved in adaptation.

Trait shifts associated with the subshrub life-history strategy in a tropical savanna.

Science.gov (United States)

Giroldo, A B; Scariot, A; Hoffmann, W A

2017-10-01

Over the past 10 million years, tropical savanna environments have selected for small growth forms within woody plant lineages. The result has been the evolution of subshrubs (geoxyles), presumably as an adaptation to frequent fire. To evaluate the traits associated with the shift from tree to subshrub growth forms, we compared seed biomass, germination, survival, resprouting, biomass allocation, and photosynthesis between congeneric trees and subshrubs, and quantified phylogenetic conservatism. Despite large differences in adult morphology between trees and subshrub species, the differences are modest in seedlings, and most of the variation in traits was explained by genus, indicating considerable phylogenic conservatism. Regardless, tree seedlings invested more heavily in aboveground growth, compared to subshrubs, which is consistent with the adult strategy of savanna trees, which depend on a large resistant-fire stem. Subshrub seedlings also invest in greater non-structural carbohydrate reserves, likely as an adaptation to the high fire frequencies typical of tropical savannas. The modest differences as seedlings suggest that selective pressures during early development may not have contributed substantially to the evolution of the subshrub growth form and that the distinct allocation and life history must arise later in life. This is consistent with the interpretation that the subshrub growth form arose as a life-history strategy in which maturity is reached at a small stem size, allowing them to reproduce despite repeated fire-induced topkill. The convergent evolution of subshrubs within multiple tree lineages reaffirms the importance of fire in the origin and diversification of the flora of mesic savannas.

Extracting Behaviorally Relevant Traits from Natural Stimuli: Benefits of Combinatorial Representations at the Accessory Olfactory Bulb.

Directory of Open Access Journals (Sweden)

Anat Kahan

2016-03-01

Full Text Available For many animals, chemosensation is essential for guiding social behavior. However, because multiple factors can modulate levels of individual chemical cues, deriving information about other individuals via natural chemical stimuli involves considerable challenges. How social information is extracted despite these sources of variability is poorly understood. The vomeronasal system provides an excellent opportunity to study this topic due to its role in detecting socially relevant traits. Here, we focus on two such traits: a female mouse's strain and reproductive state. In particular, we measure stimulus-induced neuronal activity in the accessory olfactory bulb (AOB in response to various dilutions of urine, vaginal secretions, and saliva, from estrus and non-estrus female mice from two different strains. We first show that all tested secretions provide information about a female's receptivity and genotype. Next, we investigate how these traits can be decoded from neuronal activity despite multiple sources of variability. We show that individual neurons are limited in their capacity to allow trait classification across multiple sources of variability. However, simple linear classifiers sampling neuronal activity from small neuronal ensembles can provide a substantial improvement over that attained with individual units. Furthermore, we show that some traits are more efficiently detected than others, and that particular secretions may be optimized for conveying information about specific traits. Across all tested stimulus sources, discrimination between strains is more accurate than discrimination of receptivity, and detection of receptivity is more accurate with vaginal secretions than with urine. Our findings highlight the challenges of chemosensory processing of natural stimuli, and suggest that downstream readout stages decode multiple behaviorally relevant traits by sampling information from distinct but overlapping populations of AOB neurons.

Connecting Health and Natural History: A Failed Initiative at the American Museum of Natural History, 1909–1922

Science.gov (United States)

2014-01-01

In 1909, curator Charles-Edward Winslow established a department of public health in New York City’s American Museum of Natural History (AMNH). Winslow introduced public health as a biological science that connected human health—the modern sciences of physiology, hygiene, and urban sanitation—to the natural history of plants and animals. This was the only time an American museum created a curatorial department devoted to public health. The AMNH’s Department of Public Health comprised a unique collection of live bacterial cultures—a “Living Museum”—and an innovative plan for 15 exhibits on various aspects of health. I show how Winslow, facing opposition from AMNH colleagues, gathered scientific experts and financial support, and explain the factors that made these developments seem desirable and possible. I finish with a discussion of how the Department of Public Health met an abrupt and “inglorious end” in 1922 despite the success of its collections and exhibitions. PMID:24205997

78 FR 22285 - Notice of Inventory Completion: Carnegie Museum of Natural History, Pittsburgh, PA

Science.gov (United States)

2013-04-15

....R50000] Notice of Inventory Completion: Carnegie Museum of Natural History, Pittsburgh, PA AGENCY: National Park Service, Interior. ACTION: Notice. SUMMARY: The Carnegie Museum of Natural History has... associated funerary objects should submit a written request to the Carnegie Museum of Natural History. If no...

Fish functional traits correlated with environmental variables in a temperate biodiversity hotspot.

Directory of Open Access Journals (Sweden)

Benjamin P Keck

Full Text Available The global biodiversity crisis has invigorated the search for generalized patterns in most disciplines within the natural sciences. Studies based on organismal functional traits attempt to broaden implications of results by identifying the response of functional traits, instead of taxonomic units, to environmental variables. Determining the functional trait responses enables more direct comparisons with, or predictions for, communities of different taxonomic composition. The North American freshwater fish fauna is both diverse and increasingly imperiled through human mediated disturbances, including climate change. The Tennessee River, USA, contains one of the most diverse assemblages of freshwater fish in North America and has more imperiled species than other rivers, but there has been no trait-based study of community structure in the system. We identified 211 localities in the upper Tennessee River that were sampled by the Tennessee Valley Authority between 2009 and 2011 and compiled fish functional traits for the observed species and environmental variables for each locality. Using fourth corner analysis, we identified significant correlations between many fish functional traits and environmental variables. Functional traits associated with an opportunistic life history strategy were correlated with localities subject to greater land use disturbance and less flow regulation, while functional traits associated with a periodic life history strategy were correlated with localities subject to regular disturbance and regulated flow. These are patterns observed at the continental scale, highlighting the generalizability of trait-based methods. Contrary to studies that found no community structure differences when considering riparian buffer zones, we found that fish functional traits were correlated with different environmental variables between analyses with buffer zones vs. entire catchment area land cover proportions. Using existing databases

Fish functional traits correlated with environmental variables in a temperate biodiversity hotspot.

Science.gov (United States)

Keck, Benjamin P; Marion, Zachary H; Martin, Derek J; Kaufman, Jason C; Harden, Carol P; Schwartz, John S; Strange, Richard J

2014-01-01

The global biodiversity crisis has invigorated the search for generalized patterns in most disciplines within the natural sciences. Studies based on organismal functional traits attempt to broaden implications of results by identifying the response of functional traits, instead of taxonomic units, to environmental variables. Determining the functional trait responses enables more direct comparisons with, or predictions for, communities of different taxonomic composition. The North American freshwater fish fauna is both diverse and increasingly imperiled through human mediated disturbances, including climate change. The Tennessee River, USA, contains one of the most diverse assemblages of freshwater fish in North America and has more imperiled species than other rivers, but there has been no trait-based study of community structure in the system. We identified 211 localities in the upper Tennessee River that were sampled by the Tennessee Valley Authority between 2009 and 2011 and compiled fish functional traits for the observed species and environmental variables for each locality. Using fourth corner analysis, we identified significant correlations between many fish functional traits and environmental variables. Functional traits associated with an opportunistic life history strategy were correlated with localities subject to greater land use disturbance and less flow regulation, while functional traits associated with a periodic life history strategy were correlated with localities subject to regular disturbance and regulated flow. These are patterns observed at the continental scale, highlighting the generalizability of trait-based methods. Contrary to studies that found no community structure differences when considering riparian buffer zones, we found that fish functional traits were correlated with different environmental variables between analyses with buffer zones vs. entire catchment area land cover proportions. Using existing databases and fourth corner

75 FR 435 - Notice of Inventory Completion: Field Museum of Natural History, Chicago, IL

Science.gov (United States)

2010-01-05

... Natural History, Chicago, IL. The human remains were removed from the Channel Islands in Santa Barbara and.... A detailed assessment of the human remains was made by Field Museum of Natural History professional... 407). The human remains were accessioned into the Field Museum of Natural History the same year. No...

The natural history of hepatitis C virus infection.

LENUS (Irish Health Repository)

Kenny-Walsh, E

2012-02-03

The natural history of HCV infection remains ill-defined. The knowledge accumulated on the progression of HCV to date is important, however. It is now abundantly clear that the progression of disease is generally slow, and the development of cirrhosis and its complications is a possibility, not a probability as hitherto thought. Predicting the outcome remains a quandary for clinicians. Ultimately it will be possible to define the natural history of hepatitis C infection through a combination of research in the fields of virology, immunology, and molecular biology and by monitoring the biochemical and histologic progress of the disease. Only then will it be possible to intervene appropriately and develop new therapies to prevent the progression to cirrhosis and hepatocellular carcinoma.

Thyroid cancer: Natural history, management strategies and outcomes

International Nuclear Information System (INIS)

Shaha, Ashok R.

1997-01-01

Objectives: To understand the natural history of thyroid cancer and high risk groups; To define the biological behavior of thyroid cancer and relate it to various prognostic factors and risk groups; To divide the management strategies into conservation, radical surgery and radioactive iodine treatment; To define the role of external radiation therapy and the management of complex and advanced thyroid cancer; To analyze the results of management of anaplastic thyroid cancer and make a plea for combined modality treatment; To define the current role of genetic studies in medullary thyroid cancer. At the end of this refresher course, the attendees will be able to understand the natural history, the prognostic factors and risk groups and surgical and combined modality treatment in thyroid cancer

Natural History Specimen Digitization: Challenges and Concerns

Directory of Open Access Journals (Sweden)

Ana Vollmar

2010-10-01

Full Text Available A survey on the challenges and concerns invovled with digitizing natural history specimens was circulated to curators, collections managers, and administrators in the natural history community in the Spring of 2009, with over 200 responses received. The overwhelming barrier to digitizing collections was a lack of funding, based on a limited number of sources, leaving institutions mostly responsible for providing the necessary support. The uneven digitization landscape leads to a patchy accumulation of records at varying qualities, and based on different priorities, ulitimately influencing the data's fitness for use. The survey also found that although the kind of specimens found in collections and their storage can be quite varible, there are many similar challenges when digitizing including imaging, automated text scanning and parsing, geo-referencing, etc. Thus, better communication between domains could foster knowledge on digitization leading to efficiencies that could be disseminated through documentation of best practices and training.

On the Origin of Complex Adaptive Traits: Progress Since the Darwin Versus Mivart Debate.

Science.gov (United States)

Suzuki, Takao K

2017-06-01

The evolutionary origin of complex adaptive traits has been a controversial topic in the history of evolutionary biology. Although Darwin argued for the gradual origins of complex adaptive traits within the theory of natural selection, Mivart insisted that natural selection could not account for the incipient stages of complex traits. The debate starting from Darwin and Mivart eventually engendered two opposite views: gradualism and saltationism. Although this has been a long-standing debate, the issue remains unresolved. However, recent studies have interrogated classic examples of complex traits, such as the asymmetrical eyes of flatfishes and leaf mimicry of butterfly wings, whose origins were debated by Darwin and Mivart. Here, I review recent findings as a starting point to provide a modern picture of the evolution of complex adaptive traits. First, I summarize the empirical evidence that unveils the evolutionary steps toward complex traits. I then argue that the evolution of complex traits could be understood within the concept of "reducible complexity." Through these discussions, I propose a conceptual framework for the formation of complex traits, named as reducible-composable multicomponent systems, that satisfy two major characteristics: reducibility into a sum of subcomponents and composability to construct traits from various additional and combinatorial arrangements of the subcomponents. This conceptual framework provides an analytical foundation for exploring evolutionary pathways to build up complex traits. This review provides certain essential avenues for deciphering the origin of complex adaptive traits. © 2017 Wiley Periodicals, Inc.

Using large-scale data analysis to assess life history and behavioural traits: the case of the reintroduced White stork Ciconia ciconia population in the Netherlands

Directory of Open Access Journals (Sweden)

Doligez, B.

2004-06-01

Full Text Available The White stork Ciconia ciconia has been the object of several successful reintroduction programmes in the last decades. As a consequence, populations have been monitored over large spatial scales. Despite these intense efforts, very few reliable estimates of life history traits are available for this species. Such general knowledge however constitutes a prerequisite for investigating the consequences of conservation measures. Using the large–scale and long–term ringing and resighting data set of White storks in the Netherlands, we investigated the variation of survival and resighting rates with age, time and previous individual resighting history, and in a second step supplementary feeding, using capture–recapture models. Providing food did not seem to affect survival directly, but may have an indirect effect via the alteration of migratory behaviour. Large–scale population monitoring is important in obtaining precise and reliable estimates of life history traits and assessing the consequences of conservation measures on these traits, which will prove useful for managers to take adequate measures in future conservation strategies.

Phenotypic selection on leaf water use efficiency and related ecophysiological traits for natural populations of desert sunflowers.

Science.gov (United States)

Donovan, Lisa A; Dudley, Susan A; Rosenthal, David M; Ludwig, Fulco

2007-05-01

Plant water-use efficiency (WUE) is expected to affect plant fitness and thus be under natural selection in arid habitats. Although many natural population studies have assessed plant WUE, only a few related WUE to fitness. The further determination of whether selection on WUE is direct or indirect through functionally related traits has yielded no consistent results. For natural populations of two desert annual sunflowers, Helianthus anomalus and H. deserticola, we used phenotypic selection analysis with vegetative biomass as the proxy for fitness to test (1) whether there was direct and indirect selection on WUE (carbon isotope ratio) and related traits (leaf N, area, succulence) and (2) whether direct selection was consistent with hypothesized drought/dehydration escape and avoidance strategies. There was direct selection for lower WUE in mesic and dry H. anomalus populations, consistent with dehydration escape, even though it is the longer lived of the two species. For mesic H. anomalus, direct selection favored lower WUE and higher N, suggesting that plants may be "wasting water" to increase N delivery via the transpiration stream. For the shorter lived H. deserticola in the direr habitat, there was indirect selection for lower WUE, inconsistent with drought escape. There was also direct selection for higher leaf N, succulence and leaf size. There was no direct selection for higher WUE consistent with dehydration avoidance in either species. Thus, in these natural populations of two desert dune species higher fitness was associated with some combination direct and indirect selection for lower WUE, higher leaf N and larger leaf size. Our understanding of the adaptive value of plant ecophysiological traits will benefit from further consideration of related traits such as leaf nitrogen and more tests in natural populations.

A trait-based framework for stream algal communities.

Science.gov (United States)

Lange, Katharina; Townsend, Colin Richard; Matthaei, Christoph David

2016-01-01

The use of trait-based approaches to detect effects of land use and climate change on terrestrial plant and aquatic phytoplankton communities is increasing, but such a framework is still needed for benthic stream algae. Here we present a conceptual framework of morphological, physiological, behavioural and life-history traits relating to resource acquisition and resistance to disturbance. We tested this approach by assessing the relationships between multiple anthropogenic stressors and algal traits at 43 stream sites. Our "natural experiment" was conducted along gradients of agricultural land-use intensity (0-95% of the catchment in high-producing pasture) and hydrological alteration (0-92% streamflow reduction resulting from water abstraction for irrigation) as well as related physicochemical variables (total nitrogen concentration and deposited fine sediment). Strategic choice of study sites meant that agricultural intensity and hydrological alteration were uncorrelated. We studied the relationships of seven traits (with 23 trait categories) to our environmental predictor variables using general linear models and an information-theoretic model-selection approach. Life form, nitrogen fixation and spore formation were key traits that showed the strongest relationships with environmental stressors. Overall, FI (farming intensity) exerted stronger effects on algal communities than hydrological alteration. The large-bodied, non-attached, filamentous algae that dominated under high farming intensities have limited dispersal abilities but may cope with unfavourable conditions through the formation of spores. Antagonistic interactions between FI and flow reduction were observed for some trait variables, whereas no interactions occurred for nitrogen concentration and fine sediment. Our conceptual framework was well supported by tests of ten specific hypotheses predicting effects of resource supply and disturbance on algal traits. Our study also shows that investigating a

Hormesis on life-history traits: is there such thing as a free lunch?

Science.gov (United States)

Jager, Tjalling; Barsi, Alpar; Ducrot, Virginie

2013-03-01

The term "hormesis" is used to describe dose-response relationships where the response is reversed between low and high doses of a stressor (generally, stimulation at low doses and inhibition at high ones). A mechanistic explanation is needed to interpret the relevance of such responses, but there does not appear to be a single universal mechanism underlying hormesis. When the endpoint is a life-history trait such as growth or reproduction, a stimulation of the response comes with costs in terms of resources. Organisms have to obey the conservation laws for mass and energy; there is no such thing as a free lunch. Based on the principles of Dynamic Energy Budget theory, we introduce three categories of explanations for hormesis that obey the conservation laws: acquisition (i.e., increasing the input of energy into the individual), allocation (i.e., rearranging the energy flows over various traits) and medication (e.g., the stressor is an essential element or acts as a cure for a disease or infection). In this discussion paper, we illustrate these explanations with cases where they might apply, and elaborate on the potential consequences for field populations.

Life history traits influence the strength of distance- and density-dependence at different life stages of two Amazonian palms.

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Choo, Juanita; Carasco, Cecilia; Alvarez-Loayza, Patricia; Simpson, Beryl B; Economo, Evan P

2017-07-01

Natural enemies are known to be important in regulating plant populations and contributing to species coexistence (Janzen-Connell effects). The strength of Janzen-Connell effects (both distance- and density-effects) varies across species, but the life history traits that may mediate such a variation are not well understood. This study examined Janzen-Connell effects across the life stages (seed through adult stages) of two sympatric palm species with distinct phenologies and shade tolerances, two traits that may mediate the strength and timing of Janzen-Connell effects. Populations of two common palm species, Attalea phalerata and Astrocaryum murumuru , were studied in Manu National Park, Peru. Seed predation experiments were conducted to assess Janzen-Connell effects at the seed stage. In the post-seed stages, spatial point pattern analyses of the distributions of individuals and biomass were used to infer the strength of distance- and density-effects. Seed predation was both negative distance- and density-dependent consistent with the Janzen-Connell effects. However, only seedling recruitment for asynchronously fruiting Attalea phalerata was depressed near adults while recruitment remained high for synchronously fruiting Astrocaryum murumuru , consistent with weak distance-effects. Negative density-effects were strong in the early stages for shade-intolerant Attalea phalerata but weak or absent in shade-tolerant Astrocaryum murumuru. Distance- and density-effects varied among the life stages of the two palm species in a manner that corresponded to their contrasting phenology and shade tolerance. Generalizing such connections across many species would provide a route to understanding how trait-mediated Janzen-Connell effects scale up to whole communities of species. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Phenotypic plasticity in fish life-history traits in two neotropical reservoirs: Petit-Saut Reservoir in French Guiana and Brokopondo Reservoir in Suriname

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Bernard de Mérona

Full Text Available Fish species are known for their large phenotypic plasticity in life-history traits in relation to environmental characteristics. Plasticity allows species to increase their fitness in a given environment. Here we examined the life-history response of fish species after an abrupt change in their environment caused by the damming of rivers. Two reservoirs of different age, both situated on the Guiana Shield, were investigated: the young Petit-Saut Reservoir in French Guiana (14 years and the much older Brokopondo Reservoir in Suriname (44 years. Six life-history traits in 14 fish species were studied and compared to their value in the Sinnamary River prior to the completion of Petit-Saut Reservoir. The traits analyzed were maximum length, absolute and relative length at first maturation, proportion of mature oocytes in ripe gonad, batch fecundity and mean size of mature oocytes. The results revealed a general increase of reproductive effort. All species showed a decrease in maximum length. Compared to the values observed before the dam constructions, eight species had larger oocytes and three species showed an increased batch fecundity. These observed changes suggest a trend towards a pioneer strategy. The changes observed in Petit-Saut Reservoir also seemed to apply to the 30 years older Brokopondo Reservoir suggesting that these reservoirs remain in a state of immaturity for a long time.

Journal of East African Natural History: Submissions

African Journals Online (AJOL)

2017-11-01

Nov 1, 2017 ... Author Guidelines. Submission: manuscripts should be submitted as a Word document in an email attachment, to the Editor-in-Chief, Journal of East African Natural History at office@naturekenya.org. The manuscript should be accompanied by a covering letter from the author, or in the case of multiple ...

Modernizing Natural History: Berkeley's Museum of Vertebrate Zoology in Transition.

Science.gov (United States)

Sunderland, Mary E

2013-01-01

Throughout the twentieth century calls to modernize natural history motivated a range of responses. It was unclear how research in natural history museums would participate in the significant technological and conceptual changes that were occurring in the life sciences. By the 1960s, the Museum of Vertebrate Zoology at the University of California, Berkeley, was among the few university-based natural history museums that were able to maintain their specimen collections and support active research. The MVZ therefore provides a window to the modernization of natural history. This paper concentrates on the directorial transitions that occurred at the MVZ between 1965 and 1971. During this period, the MVZ had four directors: Alden H. Miller (Director 1940-1965), an ornithologist; Aldo Starker Leopold (Acting Director 1965-1966), a conservationist and wildlife biologist; Oliver P. Pearson (Director 1966-1971), a physiologist and mammalogist; and David B. Wake (Director 1971-1998), a morphologist, developmental biologist, and herpetologist. The paper explores how a diversity of overlapping modernization strategies, including hiring new faculty, building infrastructure to study live animals, establishing new kinds of collections, and building modern laboratories combined to maintain collections at the MVZ's core. The paper examines the tensions between the different modernization strategies to inform an analysis of how and why some changes were institutionalized while others were short-lived. By exploring the modernization of collections-based research, this paper emphasizes the importance of collections in the transformation of the life sciences.

Oxidative stress physiology in relation to life history traits of a free-living vertebrate : the spotted snow skink, Niveoscincus ocellatus

NARCIS (Netherlands)

Isaksson, Caroline; While, Geoffrey M.; Olsson, Mats; Komdeur, Jan; Wapstra, Erik

Recent research suggests that oxidative stress, via its links to metabolism and senescence, is a key mechanism linking life history traits such as fecundity and growth with survival; however, this has rarely been put under empirical scrutiny within free-living populations. Using a wild population of

Effects of soybean resistance on variability in life history traits of the higher trophic level parasitoid Meteorus pulchricornis (Hymenoptera: Braconidae).

Science.gov (United States)

Li, X; Li, B; Xing, G; Meng, L

2017-02-01

To extrapolate the influence of plant cultivars varying in resistance levels to hosts on parasitoid life history traits, we estimated variation in parasitoid developmental and reproductive performances as a function of resistance in soybean cultivars, which were randomly chosen from a line of resistant genotypes. Our study showed that the parasitoid Meteorus pulchricornis varied widely in offspring survival and lifetime fecundity, but varied slightly in development time and adult body size, in response to the soybean cultivars that varied in resistance to the host Spodoptera litura. Furthermore, the variability in survival and lifetime fecundity was different between attacking the 2nd and the 4th instar host larvae, varying more in survival but less in lifetime fecundity when attacking the 4th than 2nd instar larvae. Our study provides further evidence supporting that plant resistance to herbivorous hosts have variable effects on different life history traits of higher trophic level parasitoids.

Natural history and epidemiology of post transplantation diabetes ...

African Journals Online (AJOL)

PRACTICE POINTS - Natural history and epidemiology of post transplantation diabetes mellitus. ... Conclusions: The most important risk factor predisposing to the development of PTD is the immunosuppressive drugs. The selection of immunosuppressive regimen should take into account individuals diabetes risk profile ...

["Artificial animals etc." Popular natural history and bourgeois curiosity around 1900].

Science.gov (United States)

Wessely, Christina

2008-01-01

During the 19th and early 20th century zoological gardens ranged among the most prominent places of popular natural history While aristocratic owners of earlier menageries installed animal collections mostly to symbolize their power over nature as well as to display their extensive diplomatic relations, the zoological gardens founded from the 1830s onwards all over Europe by members of the local bourgeois elites were supposed to mediate their social and political values by "enjoyably educating" a broader public. The new zoos were introduced as places at the antipodes of the frenzy, noise and motion of modern urban life, as spaces of pure, authentic nature whose observation would teach people a reasonable and responsible way of life in a civilised bourgeois community. Taking the Berlin Zoo as an example this paper questions these programmatic imaginations by showing how popular Naturkunde (natural history) was informed by cultures of urban entertainment and spectacle. It discusses the numerous relations and productive tensions that evolved out of the establishment of a "realm of nature" in the middle of the ever growing modern metropolis and investigates the consequences the zoo's rise as "the city's most important attraction" around the turn of the century had for the public perception of natural history as well as for the institution's scientific program.

Life history trade-offs and relaxed selection can decrease bacterial virulence in environmental reservoirs.

Directory of Open Access Journals (Sweden)

Lauri Mikonranta

Full Text Available Pathogen virulence is usually thought to evolve in reciprocal selection with the host. While this might be true for obligate pathogens, the life histories of opportunistic pathogens typically alternate between within-host and outside-host environments during the infection-transmission cycle. As a result, opportunistic pathogens are likely to experience conflicting selection pressures across different environments, and this could affect their virulence through life-history trait correlations. We studied these correlations experimentally by exposing an opportunistic bacterial pathogen Serratia marcescens to its natural protist predator Tetrahymena thermophila for 13 weeks, after which we measured changes in bacterial traits related to both anti-predator defence and virulence. We found that anti-predator adaptation (producing predator-resistant biofilm caused a correlative attenuation in virulence. Even though the direct mechanism was not found, reduction in virulence was most clearly connected to a predator-driven loss of a red bacterial pigment, prodigiosin. Moreover, life-history trait evolution was more divergent among replicate populations in the absence of predation, leading also to lowered virulence in some of the 'predator absent' selection lines. Together these findings suggest that the virulence of non-obligatory, opportunistic bacterial pathogens can decrease in environmental reservoirs through life history trade-offs, or random accumulation of mutations that impair virulence traits under relaxed selection.

Natural History of Rotator Cuff Disease and Implications on Management

Science.gov (United States)

Hsu, Jason

2015-01-01

Degenerative rotator cuff disease is commonly associated with ageing and is often asymptomatic. The factors related to tear progression and pain development are just now being defined through longitudinal natural history studies. The majority of studies that follow conservatively treated painful cuff tears or asymptomatic tears that are monitored at regular intervals show slow progression of tear enlargement and muscle degeneration over time. These studies have highlighted greater risks for disease progression for certain variables, such as the presence of a full-thickness tear and involvement of the anterior aspect supraspinatus tendon. Coupling the knowledge of the natural history of degenerative cuff tear progression with variables associated with greater likelihood of successful tendon healing following surgery will allow better refinement of surgical indications for rotator cuff disease. In addition, natural history studies may better define the risks of nonoperative treatment over time. This article will review pertinent literature regarding degenerative rotator cuff disease with emphasis on variables important to defining appropriate initial treatments and refining surgical indications. PMID:26726288

Pigmentary traits, family history of melanoma and the risk of endometriosis: a cohort study of US women.

Science.gov (United States)

Kvaskoff, Marina; Han, Jiali; Qureshi, Abrar A; Missmer, Stacey A

2014-02-01

Endometriosis has been associated with a higher risk of cutaneous melanoma, but the mechanisms underlying this association are unknown.Some constitutional factors known to influence melanoma risk have been associated with endometriosis in some retrospective studies. However, prospective data are scarce, and more research is needed to confirm this potentially novel endometriosis risk profile. To investigate the relationships between pigmentary traits, family history of melanoma and endometriosis risk, we analysed data from the Nurses’ Health Study II, a cohort of 116 430 female US nurses aged 25–42 years at inclusion in 1989. Data were collected every 2 years with 20 years of follow-up for these analyses. We used Cox proportional hazards regression models to compute relative risks(RRs) and 95% confidence intervals (CIs). During 1 212 499 woman-years of follow-up, 4763 cases of laparoscopically-confirmed endometriosis were reported among premenopausal Caucasian women. Endometriosis risk was increased with presence of naevi on the lower legs (RR=1.08, 95% CI=1.021.14) and higher level of skin’s burning reaction to sun exposure in childhood/adolescence (‘burn with blisters’: RR=1.20,95% CI=1.061.36) compared with ‘practically none’;P(trend)=0.0006) and family history of melanoma (RR=1.13, 95%CI=1.011.26). This assessment reports modest associations between several pigmentary traits, family history of melanoma and endometriosis risk,corroborating the results from previous retrospective studies. Our findings call for further research to better understand the mechanisms under lying these associations.

75 FR 45659 - Notice of Inventory Completion: Field Museum of Natural History, Chicago, IL

Science.gov (United States)

2010-08-03

... possession of the Field Museum of Natural History, Chicago, IL. The human remains and associated funerary... assessment of the human remains was made by the Field Museum of Natural History professional staff in... History have determined that, pursuant to 25 U.S.C. 3001(9), the human remains described above represent...

The natural history of Perthes' disease

OpenAIRE

Terjesen, Terje; Wiig, Ola; Svenningsen, Svein

2010-01-01

Background The prognosis in Perthes' disease varies considerably according to certain risk factors, but there is no concensus regarding the relative importance of these factors. We assessed the natural history of the disease and defined prognostic factors of value in deciding the proper treatment. Patients and methods During the 5-year period 1996?2000, a nationwide study on Perthes' disease was performed in Norway. 425 patients were registered. The present study involved the 212 children (me...

The Effect of Istighfar on State and Trait Anxiety

Directory of Open Access Journals (Sweden)

Ahmet Canan Karakaş

2017-09-01

Full Text Available Istighfar (seeking forgiveness of Allah and tawbah (repentance are as old as at least the human history. Anxiety is also a need of human nature. Human develops the strategies to cope with challenges. One of them is religious coping. One of the religious coping ways is istighfar. Constantly performing istighfar may make easier to deal with anxiety. Thus, in this study, the state-trait anxiety scale was applied to the final year undergraduate students. The experimental and control groups of 20 persons were comprised of students with higher anxiety level. The experimental group was told to do istighfar 100 times per day during one month. In the end of this practice, a decrease was observed in the state-trait anxiety average of experimental group.

Life-History Traits and Population Structure of Pederson Cleaner Shrimps Ancylomenes pedersoni.

Science.gov (United States)

Gilpin, Jessica A; Chadwick, Nanette E

2017-12-01

Cleaner organisms perform key functional roles in reducing rates of parasitism in marine communities. Pederson cleaner shrimps Ancylomenes pedersoni are major cleaners of reef fishes in the tropical western Atlantic and form obligate symbioses with host sea anemones. Information about their life-history traits would contribute to understanding how symbiosis impacts life-history evolution in crustaceans, but little is known about patterns of growth and reproduction in this anemone shrimp. We quantified growth, sexual reproduction, senescence, and mortality in individuals of A. pedersoni under laboratory conditions and their abundance and population size structure on coral reefs in St. Thomas, U.S. Virgin Islands. Von Bertalanffy growth curves were fitted to the data to determine age-size relationships, and the Beverton-Holt model was used to estimate mortality rates and size at maximum yield. Individuals grew rapidly when young, then slowed their growth after reaching sexual maturity at ~6 months. Individuals were gonochoric, with males attaining significantly smaller body sizes and shorter life spans than did females. Prior to death at <2 years, members of both genders exhibited senescence during which they ceased reproducing, shrank (females only), and decreased their activity levels over ~1-4 weeks. Field populations were abundant and composed mostly of juveniles during both years examined. Populations appeared to be stable but highly dynamic in terms of individuals, reaching maximum yield at 4 months of age. We conclude that obligate symbiosis with large sea anemones and cleaner mutualism with reef fishes both contribute to explaining aspects of the life history of Pederson shrimps, especially their apparent mating system of pure-search polygynandry. This life-history information also provides a scientific basis for sustainable fishery management and aquaculture of this key coral reef organism.

Life history traits and exploitation affect the spatial mean-variance relationship in fish abundance.

Science.gov (United States)

Kuo, Ting-chun; Mandal, Sandip; Yamauchi, Atsushi; Hsieh, Chih-hao

2016-05-01

Fishing is expected to alter the spatial heterogeneity of fishes. As an effective index to quantify spatial heterogeneity, the exponent b in Taylor's power law (V = aMb) measures how spatial variance (V) varies with changes in mean abundance (M) of a population, with larger b indicating higher spatial aggregation potential (i.e., more heterogeneity). Theory predicts b is related with life history traits, but empirical evidence is lacking. Using 50-yr spatiotemporal data from the California Current Ecosystem, we examined fishing and life history effects on Taylor's exponent by comparing spatial distributions of exploited and unexploited fishes living in the same environment. We found that unexploited species with smaller size and generation time exhibit larger b, supporting theoretical prediction. In contrast, this relationship in exploited species is much weaker, as the exponents of large exploited species were higher than unexploited species with similar traits. Our results suggest that fishing may increase spatial aggregation potential of a species, likely through degrading their size/age structure. Results of moving-window cross-correlation analyses on b vs. age structure indices (mean age and age evenness) for some exploited species corroborate our findings. Furthermore, through linking our findings to other fundamental ecological patterns (occupancy-abundance and size-abundance relationships), we provide theoretical arguments for the usefulness of monitoring the exponent b for management purposes. We propose that age/size-truncated species might have lower recovery rate in spatial occupancy, and the spatial variance-mass relationship of a species might be non-linear. Our findings provide theoretical basis explaining why fishery management strategy should be concerned with changes to the age and spatial structure of exploited fishes.

A life history approach to delineating how harsh environments and hawk temperament traits differentially shape children's problem-solving skills.

Science.gov (United States)

Suor, Jennifer H; Sturge-Apple, Melissa L; Davies, Patrick T; Cicchetti, Dante

2017-08-01

Harsh environments are known to predict deficits in children's cognitive abilities. Life history theory approaches challenge this interpretation, proposing stressed children's cognition becomes specialized to solve problems in fitness-enhancing ways. The goal of this study was to examine associations between early environmental harshness and children's problem-solving outcomes across tasks varying in ecological relevance. In addition, we utilize an evolutionary model of temperament toward further specifying whether hawk temperament traits moderate these associations. Two hundred and one mother-child dyads participated in a prospective multimethod study when children were 2 and 4 years old. At age 2, environmental harshness was assessed via maternal report of earned income and observations of maternal disengagement during a parent-child interaction task. Children's hawk temperament traits were assessed from a series of unfamiliar episodes. At age 4, children's reward-oriented and visual problem-solving were measured. Path analyses revealed early environmental harshness and children's hawk temperament traits predicted worse visual problem-solving. Results showed a significant two-way interaction between children's hawk temperament traits and environmental harshness on reward-oriented problem-solving. Simple slope analyses revealed the effect of environmental harshness on reward-oriented problem-solving was specific to children with higher levels of hawk traits. Results suggest early experiences of environmental harshness and child hawk temperament traits shape children's trajectories of problem-solving in an environment-fitting manner. © 2017 Association for Child and Adolescent Mental Health.

The Royal Society, natural history and the peoples of the 'New World(s)', 1660-1800.

Science.gov (United States)

Gascoigne, John

2009-12-01

This paper focuses on the response of the Royal Society to the increasing contact with parts of the globe beyond Europe. Such contact was in accord with the programme of Baconian natural history that the early Royal Society espoused, but it also raised basic questions about the extent and nature of the pursuit of natural history. In particular, the paper is concerned with the attention paid to one particular branch of natural history, the study of other peoples and their customs. Such scrutiny of other peoples in distant lands raised basic questions about what methods natural history should employ and the extent to which it could serve as a foundation for more general and theoretical claims. By taking a wide sweep from the beginnings of the Royal Society until the end of the eighteenth century it is hoped light will be shed on the changing understanding of natural history over this period.

Natural History of HPV and Cervical Cancer

Centers for Disease Control (CDC) Podcasts

2009-10-12

Dr. Phil Castle, an intramural research scientist at the National Institutes of Health, talks about the natural history of human papillomavirus (HPV) infections, and cervical cancer and other anogenital cancers.  Created: 10/12/2009 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP), Division of Cancer Prevention and Control (DCPC).   Date Released: 6/9/2010.

Bleeding-Heart Liberals and Hard-Hearted Conservatives: Subtle Political Dehumanization Through Differential Attributions of Human Nature and Human Uniqueness Traits

Directory of Open Access Journals (Sweden)

Jarret T. Crawford

2013-10-01

Full Text Available This research demonstrated that human nature (HN and human uniqueness (HU traits capture the content of Americans’ stereotypes about liberals and conservatives, respectively. Consistent with expectations derived from dehumanization theory, people more strongly associated HN traits with liberals than with conservatives, and more strongly associated HU traits with conservatives than with liberals. A trait × target ideology × perceiver ideology × trait valence interaction suggested that both liberals and conservatives more strongly associated their ingroup with stereotype-consistent positive traits, and their outgroup with stereotype-consistent negative traits. Mediation analyses revealed that outgroup antipathy, but not ingroup liking, explained the relationship between ideology and political outgroup dehumanization. Finally, humanness traits captured subtle differences in political stereotype content not captured with the warmth and competence dimensions derived from the stereotype content model. Together, these results indicate that differential attributions of HN and HU traits capture political stereotype content and function to subtly dehumanize one’s political opponents.

Scientific literacy: Role of natural history studies in constructing understanding of the nature of science

Science.gov (United States)

Lutz, Martha Victoria Rosett

2002-01-01

Scientific literacy is a central goal of science education. One purpose of this investigation was to reevaluate the definition of 'scientific literacy.' Another purpose was to develop and implement new curriculum involving natural history experiments with insects, with the goal of allowing students opportunities to construct an understanding of the nature of science, a crucial aspect of scientific literacy. This investigation was a qualitative case study. Methods of data collection included direct observations, analysis of sketches and written products created by students and class-room teachers, and analysis of audio tapes. Major findings include: (1) Scientific literacy is generally defined by lists of factual information which students are expected to master. When asked to evaluate their knowledge of selected items on a list published in a science education reform curriculum guide, 15 practicing scientists reported lack of familiarity or comprehension with many items, with the exception of items within their areas of specialization. (2) Genuine natural history experiments using insects can be incorporated into the existing school schedule and need not require any increase in the budget for science materials. (3) Students as young as first through third grade can learn the manual techniques and conceptual skills necessary for designing and conducting original natural history experiments, including manipulating the insects, making accurate sketches, developing test able hypotheses, recording data, and drawing conclusions from their data. Students were generally enthusiastic both about working with live insects and also conducting genuine science experiments. (4) Girls appear both positive and engaged with natural history activities and may be more likely than boys to follow through on designing, conducting, and reporting on independent experiments. The results imply that a valid definition of scientific literacy should be based on the ability to acquire scientific

76 FR 48179 - Notice of Inventory Completion: Slater Museum of Natural History, University of Puget Sound...

Science.gov (United States)

2011-08-08

... Museum of Natural History, University of Puget Sound, Tacoma, WA AGENCY: National Park Service, Interior. ACTION: Notice. SUMMARY: The Slater Museum of Natural History, University of Puget Sound has completed an... contact the Slater Museum of Natural History, University of Puget Sound. Disposition of the human remain...

Cerebral cavernous malformations: natural history and clinical management.

Science.gov (United States)

Gross, Bradley A; Du, Rose

2015-01-01

Cavernous malformations (CMs) are angiographically-occult clusters of dilated sinusoidal channels that may present clinically with seizures, focal neurological deficits and/or hemorrhage. Across natural history studies, the annual hemorrhage rate ranged from 1.6-3.1% per patient-year, decreasing to 0.08-0.2% per patient-year for incidental CMs and to 0.3-0.6% for the collective group of unruptured CMs. Prior hemorrhage is a significant risk factor for subsequent CM hemorrhage. Hemorrhage clustering, particularly within the first 2 years, is an established phenomenon that may confound results of natural history studies evaluating the rate of rehemorrhage. Indeed, rehemorrhage rates for hemorrhagic CMs range from 4.5-22.9% in the literature. Surgical resection is the gold standard treatment for surgically-accessible, symptomatic CMs. Incidental CMs or minimally symptomatic, surgically inaccessible eloquent lesions may be considered for observation. Stereotactic radiosurgery is a controversial treatment approach of consideration only for cases of highly aggressive, surgically inaccessible CMs.

Natural history of cerebral dot-like cavernomas

International Nuclear Information System (INIS)

Nikoubashman, O.; Wiesmann, M.; Tournier-Lasserve, E.; Mankad, K.; Bourgeois, M.; Brunelle, F.; Sainte-Rose, C.; Wiesmann, M.; Zerah, M.; Di Rocco, F.

2013-01-01

Aim: To elucidate the natural history of dot-like or “black spot” cavernomas. Materials and methods: Data of 18 children with black spot cavernomas were analysed retrospectively. Results: Eleven boys and seven girls presented 187 black spot cavernomas during a mean observation period of 5.5 years. Mean and median age at diagnosis of the 187 cavernomas was 9.6 years. There were 70 de novo black spot cavernomas. Boys presented significantly more cavernomas than girls. There were three KRIT1 mutation carriers and four PDCD10 mutation carriers. Children with a PDCD10 mutation presented significantly more lesions than those children with a KRIT1 mutation (mean number of lesions per patient: 23.3 versus 3.3, respectively). There were 10 radiological haemorrhagic events caused by 10 black spot lesions. Two of these events were symptomatic. The haemorrhage rate of black spot cavernomas was 0.7% per lesion-year. Conclusions: A mean bleeding rate of 0.7% per lesion-year is lower than the overall haemorrhage rates provided in the literature. Nonetheless, black spot cavernomas are not purely benign lesions. Furthermore, genetic mutations may play a role in the natural history of black spot cavernomas

The natural history of substance use disorders.

Science.gov (United States)

Sarvet, Aaron L; Hasin, Deborah

2016-07-01

Illicit drugs, alcohol, and tobacco use disorders contribute substantially to the global burden of disease. Knowledge about the major elements of the natural history of substance use disorders (incidence, remission, persistence, and relapse) is crucial to a broader understanding of the course and outcomes of substance use disorders. Prospective cohort studies in nonclinical samples indicate that externalizing psychopathology in earlier life, including early disordered substance use, delinquency, and personality disorders, are related to substance use disorders later in life and chronic course. Externalizing psychopathology may be initiated by early adverse experiences, for example, childhood maltreatment and stressful life events. After controlling for confounders, 'age at first use' as a causal factor for alcohol use disorder later in life and the 'drug substitution' hypothesis are not supported in general population data. Future research should focus on elaborating the causal framework that leads to the development and persistence of severe substance use disorders, with an emphasis on identifying modifiable factors for intervention by policy makers or health professionals. More research is needed on the natural history of substance use disorders in low-income and middle-income countries.

76 FR 28074 - Notice of Inventory Completion: Utah Museum of Natural History, Salt Lake City, UT

Science.gov (United States)

2011-05-13

... of the Utah Museum of Natural History, Salt Lake City, UT. The human remains were removed from Snow.... A detailed assessment of the human remains was made by the Utah Museum of Natural History... with the human remains should contact Duncan Metcalfe, Utah Museum of Natural History, 1390 E...

Defoliation and bark harvesting affect life-history traits of a tropical tree

DEFF Research Database (Denmark)

Gaoue, Orou; Horvitz, Carol; Ticktin, Tamara

2013-01-01

Selectively harvesting whole individuals in managed populations (e.g. fisheries, hunting) has substantial effects on life expectancy and age at maturity. Although demographic rates of trees are impacted by recurrent harvest of plant organs (e.g. fruit, leaf, bark) known as non-timber forest...... of life expectancy to perturbation of vital rates to the elasticities of population growth rate, emphasizing how the two kinds of elasticity address distinct biological issues and management goals. Life expectancy was shorter and reproduction delayed in the dry than in the moist region, indicating a cost...... of drought to life-history traits. Harvesting at constant rates only affects (increased) life expectancy in the moist region and (reduced) age at first reproduction in the dry region. Models in which harvest intensity varies stochastically over time show results similar to those with constant harvesting rate...

Natural history of Hymenoptera venom allergy in Eastern Spain.

Science.gov (United States)

Fernandez, J; Soriano, V; Mayorga, L; Mayor, M

2005-02-01

The natural history of stings, the clinical reaction of the patient and in vivo and in vitro tests are necessary parameters to assess before initiating Hymenoptera venom immunotherapy. In the decision to initiate immunotherapy with Hymenoptera venom, it is not usual to evaluate the natural history of the disease, which seems to be self-limiting and therefore of variable clinical significance. Our aim was to determine the natural history of Hymenoptera hypersensitivity over 4 consecutive years in a rural Mediterranean population. An epidemiological study of Hymenoptera sting reactions and possible sensitivity was carried out in 145 randomly selected subjects out of a rural Mediterranean population of 600. Seventy-two subjects, including those with a history of anaphylaxis, completed the 4-year study. The nature of their clinical reactions, age, sex, history of atopy, profession, family history of reactions to Hymenoptera insects, time elapsed since the last sting, number of stings and specific IgE and IgG were determined (the latter, to the three most important insects in the area: Apis mellifera, Polistes dominulus, and Vespula germanica). Of the 72 subjects, four subjects had systemic reactions (SR), 23 had large local reaction (LLR) and all the others (117) was minor local reactions. None who had experienced an SR had a repeat SR when re-stung over the 4-year study. Of those with LLR, 12 subjects had the same type of reaction and 11 experienced more mild local reactions when re-stung. In the SR and local reaction groups, IgE to honey bee (Hb) increased significantly during the study period, whereas in those with only LLR, specific IgE to wasp (Polistes) decreased. Specific IgG to Polistes and Vespula (wasps) decreased significantly, whereas there was no change in the specific IgG to Hb in any of the groups. The number of stings per year decreased at the end of the study in all groups, but positive-specific IgG was higher in subjects with the greatest number of

Comparing life history characteristics of Lake Michigan’s naturalized and stocked Chinook Salmon

Science.gov (United States)

Kerns, Janice A; Rogers, Mark W.; Bunnell, David B.; Claramunt, Randall M.; Collingsworth, Paris D.

2016-01-01

Lake Michigan supports popular fisheries for Chinook Salmon Oncorhynchus tshawytscha that have been sustained by stocking since the late 1960s. Natural recruitment of Chinook Salmon in Lake Michigan has increased in the past few decades and currently contributes more than 50% of Chinook Salmon recruits. We hypothesized that selective forces differ for naturalized populations born in the wild and hatchery populations, resulting in divergent life history characteristics with implications for Chinook Salmon population production and the Lake Michigan fishery. First, we conducted a historical analysis to determine if life history characteristics changed through time as the Chinook Salmon population became increasingly naturalized. Next, we conducted a 2-year field study of naturalized and hatchery stocked Chinook Salmon spawning populations to quantify differences in fecundity, egg size, timing of spawning, and size at maturity. In general, our results did not indicate significant life history divergence between naturalized and hatchery-stocked Chinook Salmon populations in Lake Michigan. Although historical changes in adult sex ratio were correlated with the proportion of naturalized individuals, changes in weight at maturity were better explained by density-dependent factors. The field study revealed no divergence in fecundity, timing of spawning, or size at maturity, and only small differences in egg size (hatchery > naturalized). For the near future, our results suggest that the limited life history differences observed between Chinook Salmon of naturalized and hatchery origin will not lead to large differences in characteristics important to the dynamics of the population or fishery.

Roles of density-dependent growth and life history evolution in accounting for fisheries-induced trait changes.

Science.gov (United States)

Eikeset, Anne Maria; Dunlop, Erin S; Heino, Mikko; Storvik, Geir; Stenseth, Nils C; Dieckmann, Ulf

2016-12-27

The relative roles of density dependence and life history evolution in contributing to rapid fisheries-induced trait changes remain debated. In the 1930s, northeast Arctic cod (Gadus morhua), currently the world's largest cod stock, experienced a shift from a traditional spawning-ground fishery to an industrial trawl fishery with elevated exploitation in the stock's feeding grounds. Since then, age and length at maturation have declined dramatically, a trend paralleled in other exploited stocks worldwide. These trends can be explained by demographic truncation of the population's age structure, phenotypic plasticity in maturation arising through density-dependent growth, fisheries-induced evolution favoring faster-growing or earlier-maturing fish, or a combination of these processes. Here, we use a multitrait eco-evolutionary model to assess the capacity of these processes to reproduce 74 y of historical data on age and length at maturation in northeast Arctic cod, while mimicking the stock's historical harvesting regime. Our results show that model predictions critically depend on the assumed density dependence of growth: when this is weak, life history evolution might be necessary to prevent stock collapse, whereas when a stronger density dependence estimated from recent data is used, the role of evolution in explaining fisheries-induced trait changes is diminished. Our integrative analysis of density-dependent growth, multitrait evolution, and stock-specific time series data underscores the importance of jointly considering evolutionary and ecological processes, enabling a more comprehensive perspective on empirically observed stock dynamics than previous studies could provide.

Taxon and trait recognition from digitized herbarium specimens using deep convolutional neural networks

KAUST Repository

Younis, Sohaib; Weiland, Claus; Hoehndorf, Robert; Dressler, Stefan; Hickler, Thomas; Seeger, Bernhard; Schmidt, Marco

2018-01-01

Herbaria worldwide are housing a treasure of hundreds of millions of herbarium specimens, which are increasingly being digitized and thereby more accessible to the scientific community. At the same time, deep-learning algorithms are rapidly improving pattern recognition from images and these techniques are more and more being applied to biological objects. In this study, we are using digital images of herbarium specimens in order to identify taxa and traits of these collection objects by applying convolutional neural networks (CNN). Images of the 1000 species most frequently documented by herbarium specimens on GBIF have been downloaded and combined with morphological trait data, preprocessed and divided into training and test datasets for species and trait recognition. Good performance in both domains suggests substantial potential of this approach for supporting taxonomy and natural history collection management. Trait recognition is also promising for applications in functional ecology.

Taxon and trait recognition from digitized herbarium specimens using deep convolutional neural networks

KAUST Repository

Younis, Sohaib

2018-03-13

Herbaria worldwide are housing a treasure of hundreds of millions of herbarium specimens, which are increasingly being digitized and thereby more accessible to the scientific community. At the same time, deep-learning algorithms are rapidly improving pattern recognition from images and these techniques are more and more being applied to biological objects. In this study, we are using digital images of herbarium specimens in order to identify taxa and traits of these collection objects by applying convolutional neural networks (CNN). Images of the 1000 species most frequently documented by herbarium specimens on GBIF have been downloaded and combined with morphological trait data, preprocessed and divided into training and test datasets for species and trait recognition. Good performance in both domains suggests substantial potential of this approach for supporting taxonomy and natural history collection management. Trait recognition is also promising for applications in functional ecology.

Life-history traits of the Miocene Hipparion concudense (Spain inferred from bone histological structure.

Directory of Open Access Journals (Sweden)

Cayetana Martinez-Maza

Full Text Available Histological analyses of fossil bones have provided clues on the growth patterns and life history traits of several extinct vertebrates that would be unavailable for classical morphological studies. We analyzed the bone histology of Hipparion to infer features of its life history traits and growth pattern. Microscope analysis of thin sections of a large sample of humeri, femora, tibiae and metapodials of Hipparion concudense from the upper Miocene site of Los Valles de Fuentidueña (Segovia, Spain has shown that the number of growth marks is similar among the different limb bones, suggesting that equivalent skeletochronological inferences for this Hipparion population might be achieved by means of any of the elements studied. Considering their abundance, we conducted a skeletechronological study based on the large sample of third metapodials from Los Valles de Fuentidueña together with another large sample from the Upper Miocene locality of Concud (Teruel, Spain. The data obtained enabled us to distinguish four age groups in both samples and to determine that Hipparion concudense tended to reach skeletal maturity during its third year of life. Integration of bone microstructure and skeletochronological data allowed us to identify ontogenetic changes in bone structure and growth rate and to distinguish three histologic ontogenetic stages corresponding to immature, subadult and adult individuals. Data on secondary osteon density revealed an increase in bone remodeling throughout the ontogenetic stages and a lesser degree thereof in the Concud population, which indicates different biomechanical stresses in the two populations, likely due to environmental differences. Several individuals showed atypical growth patterns in the Concud sample, which may also reflect environmental differences between the two localities. Finally, classification of the specimens' age within groups enabled us to characterize the age structure of both samples, which is

The Natural History of Neoplasia

Science.gov (United States)

Pitot, Henry C.

1977-01-01

The stages of initiation and promotion in the natural history of epidermal carcinogenesis have been known for many years. Recently, experimental systems other than skin have been shown to exhibit similar, if not completely analogous, stages in the natural history of neoplasia. In particular, the demonstration by Peraino and his associates that phenobarbital may enhance the production of hepatomas by a relatively subcarcinogenic dose of acetylaminofluorene was one of the first demonstrations of stages occurring in an extraepidermal neoplasm. Studies reported in this paper have demonstrated that administration of phenobarbital (0.05% in the diet) for 6 months following a single dose of diethylnitrosamine (5 to 10 mg/kg) given within 24 hours after partial hepatectomy resulted in a marked increase in the number of enzyme-altered foci in the liver as well as in the production of hepatocellular carcinomas. This was compared to animals receiving only a single dose of diethylnitrosamine following partial hepatectomy with no further treatment, in which only a relatively small number of foci were evident in the absence of phenobarbital feeding. Using three different enzyme markers, a distinct degree of phenotypic heterogeneity of the enzyme-altered foci in liver was demonstrated. These studies have shown that liver carcinogensis can be readily divided into two stages: a) initiation by a single dose of diethylnitrosamine following partial hepatectomy and b) promotion by the continuous feeding of phenobarbital. Furthermore, the immediate progeny of the initiated cells, the enzyme-altered focus, may be recognized by suitable microscopic means prior to the formation of gross lesions as required in the skin system. These initiated cell populations exhibit a degree of biochemical heterogeneity which reflects that seen in fully developed hepatic neoplasms, suggesting that promotion and progression in this system does not significantly alter the basic biochemical characteristics of

Phenotypic plasticity in fish life-history traits in two neotropical reservoirs : Petit-Saut Reservoir in French Guiana and Brokopondo Reservoir in Suriname

OpenAIRE

Merona de, Bernard; Mol, J.; Vigouroux, R.; Chaves, P. D.

2009-01-01

Fish species are known for their large phenotypic plasticity in life-history traits in relation to environmental characteristics. Plasticity allows species to increase their fitness in a given environment. Here we examined the life-history response of fish species after an abrupt change in their environment caused by the damming of rivers. Two reservoirs of different age, both situated on the Guiana Shield, were investigated: the young Petit-Saut Reservoir in French Guiana (14 years) and the ...

Evidences of local adaptation in quantitative traits in Prosopis alba (Leguminosae).

Science.gov (United States)

Bessega, C; Pometti, C; Ewens, M; Saidman, B O; Vilardi, J C

2015-02-01

Signals of selection on quantitative traits can be detected by the comparison between the genetic differentiation of molecular (neutral) markers and quantitative traits, by multivariate extensions of the same model and by the observation of the additive covariance among relatives. We studied, by three different tests, signals of occurrence of selection in Prosopis alba populations over 15 quantitative traits: three economically important life history traits: height, basal diameter and biomass, 11 leaf morphology traits that may be related with heat-tolerance and physiological responses and spine length that is very important from silvicultural purposes. We analyzed 172 G1-generation trees growing in a common garden belonging to 32 open pollinated families from eight sampling sites in Argentina. The multivariate phenotypes differ significantly among origins, and the highest differentiation corresponded to foliar traits. Molecular genetic markers (SSR) exhibited significant differentiation and allowed us to provide convincing evidence that natural selection is responsible for the patterns of morphological differentiation. The heterogeneous selection over phenotypic traits observed suggested different optima in each population and has important implications for gene resource management. The results suggest that the adaptive significance of traits should be considered together with population provenance in breeding program as a crucial point prior to any selecting program, especially in Prosopis where the first steps are under development.

Comorbidity, family history and personality traits in pathological gamblers compared with healthy controls.

Science.gov (United States)

Mann, K; Lemenager, T; Zois, E; Hoffmann, S; Nakovics, H; Beutel, M; Vogelgesang, M; Wölfling, K; Kiefer, F; Fauth-Bühler, M

2017-05-01

While DSM-5 classified pathological gambling as an addictive disorder, there is debate as to whether ICD-11 should follow suit. The debate hinges on scientific evidence such as neurobiological findings, family history of psychiatric disorders, psychiatric comorbidity, and personality variables. In the "Baden-Württemberg Study of Pathological Gambling", we compared a group of 515 male pathological gamblers receiving treatment with 269 matched healthy controls. We studied differences in sociodemographic characteristics, gambling-related variables, psychiatric comorbidity (lifetime), family history of psychiatric conditions, as well as personality traits such as impulsivity (Barratt Impulsiveness Scale), sensation seeking (Zuckerman's Sensation Seeking Scale) and the NEO-FFI big five. Personality traits were validated in an age- and ethnicity-matched subsample of "pure" gamblers without any psychiatric comorbidity (including nicotine dependence). Data were analyzed using two-sample t-tests, Chi 2 analyses, Fisher's exact test and Pearson correlation analysis, as appropriate. Bonferroni correction was applied to correct for multiple comparisons. Only 1% of the gamblers had been diagnosed with an impulse control disorder other than gambling (ICD-10). Notably, 88% of the gamblers in our sample had a comorbid diagnosis of substance dependence. The highest axis I comorbidity rate was for nicotine dependence (80%), followed by alcohol dependence (28%). Early age of first gambling experience was correlated with gambling severity. Compared to first-degree relatives of controls, first-degree relatives of pathological gamblers were more likely to suffer from alcohol dependence (27.0% vs. 7.4%), pathological gambling (8.3% vs. 0.7%) and suicide attempts (2.7% vs. 0.4%). Significant group differences were observed for the NEO-FFI factors neuroticism, agreeableness and conscientiousness. Gamblers were also more impulsive than controls, but did not differ from controls in terms of

Melanins in Fossil Animals: Is It Possible to Infer Life History Traits from the Coloration of Extinct Species?

OpenAIRE

Negro, Juan J.; Fynlayson, Clive; Galván, Ismael

2018-01-01

Paleo-colour scientists have recently made the transition from describing melanin-based colouration in fossil specimens to inferring life-history traits of the species involved. Two such cases correspond to counter-shaded dinosaurs: dark-coloured due to melanins dorsally, and light-coloured ventrally. We believe that colour reconstruction of fossils based on the shape of preserved microstructures—the majority of paleo-colour studies involve melanin granules—is not without risks. In addition, ...

TOWARDS DEMAND DRIVEN PUBLISHING: APPROCHES TO THE PRIORITISATION OF DIGITISATION OF NATURAL HISTORY COLLECTIONS DATA

Directory of Open Access Journals (Sweden)

Vishwas Chavan

2010-10-01

Full Text Available Natural history collections represent a vast repository of biodiversity data of international significance. There is an imperative to capture the data through digitisation projects in order to expose the data to new and established users of biodiversity data. On the basis of review of current state of digitization of natural history collections, a demand driven approach is advocated through the use of metadata to promote and increase access to natural history collection data.

So what should a natural mortality curve look like for oysters?

NARCIS (Netherlands)

Mann, R.M.; Walles, B.; Troost, K.

2012-01-01

Natural mortality rate (M) of a population describes the interaction of recruitment, growth and loss to environmental factors (both physical and biological). It reflects species life history traits, a product of selection over evolutionary time scales. Fishing mortality (F) describes loss to

Conserving marine biodiversity: insights from life-history trait candidate genes in Atlantic cod (Gadus morhua)

DEFF Research Database (Denmark)

Hansen, Jakob Hemmer; Therkildsen, Nina Overgaard; Meldrup, Dorte

2014-01-01

Recent technological developments have facilitated an increased focus on identifying genomic regions underlying adaptive trait variation in natural populations, and it has been advocated that this information should be important for designating population units for conservation. In marine fishes...... are under selection in natural populations of Atlantic cod. Furthermore, we find that patterns of variation in outlier markers do not align with those observed at selectively neutral markers, and that outlier markers identify conservation units on finer geographical scales than those revealed when analysing...... only neutral markers. Accordingly, results also suggest that information about adaptive genetic variation will be useful for targeted conservation and management in this and other marine species...

A natural history of mathematics: George Peacock and the making of English algebra.

Science.gov (United States)

Lambert, Kevin

2013-06-01

In a series of papers read to the Cambridge Philosophical Society through the 1820s, the Cambridge mathematician George Peacock laid the foundation for a natural history of arithmetic that would tell a story of human progress from counting to modern arithmetic. The trajectory of that history, Peacock argued, established algebraic analysis as a form of universal reasoning that used empirically warranted operations of mind to think with symbols on paper. The science of counting would suggest arithmetic, arithmetic would suggest arithmetical algebra, and, finally, arithmetical algebra would suggest symbolic algebra. This philosophy of suggestion provided the foundation for Peacock's "principle of equivalent forms," which justified the practice of nineteenth-century English symbolic algebra. Peacock's philosophy of suggestion owed a considerable debt to the early Cambridge Philosophical Society culture of natural history. The aim of this essay is to show how that culture of natural history was constitutively significant to the practice of nineteenth-century English algebra.

Natural history and surgical management of radiation enteritis

International Nuclear Information System (INIS)

Galland, R.B.; Spencer, J.

1987-01-01

The natural history and surgical management of radio enteritis is reviewed. Predisposing factors include the dose of radiation patients build, combination with chemotherapy, previous operations and vascular disease. Management is related to the stage of disease at presentation, and tailored to the clinical problem. Surgical management must take into account the poor healing associated with irradiated intestine. (author)

An Amphibious Being: How Maritime Surveying Reshaped Darwin's Approach to Natural History.

Science.gov (United States)

Sponsel, Alistair

2016-06-01

This essay argues that Charles Darwin's distinctive approach to studying distribution and diversity was shaped by his face-to-face interactions with maritime surveyors during the voyage of H.M.S. Beagle (1831-1836). Introducing their hydrographic surveying methods into natural history enabled him to compare fossil and living marine organisms, to compare sedimentary rocks to present-day marine sediments, and to compare landscapes to submarine topology, thereby realizing Charles Lyell's fanciful ambition for a superior form of geology that might be practiced by an "amphibious being." Darwin's theories of continental uplift, coral reef formation, and the origin of species all depended on his amphibious natural history. This essay contributes to our understanding of theorizing in nineteenth-century natural history by illustrating that specific techniques of observing and collecting could themselves help to generate a particular theoretical orientation and, indeed, that such practical experiences were a more proximate source of Darwin's "Humboldtian" interest in distribution and diversity than Alexander von Humboldt's writings themselves. Darwin's debt to the hydrographers became obscured in two ways: through the "funneling" of credit produced by single-authorship publication in natural history and the "telescoping" of memory by which Darwin's new theories made him recall his former researches as though he had originally undertaken them for the very purpose of producing the later theory.

Natural history of vestibular schwannomas and hearing loss in NF2 patients.

Science.gov (United States)

Peyre, M; Bernardeschi, D; Sterkers, O; Kalamarides, M

2015-07-13

Bilateral vestibular schwannomas are the hallmark of neurofibromatosis 2 (NF2), occurring in 95% of patients. These tumors are associated with significant morbidity due to hearing loss, tinnitus, imbalance and facial weakness. As radiosurgery and chemotherapy have been recently introduced in the treatment armamentarium in addition to surgery, a thorough evaluation of vestibular schwannoma natural history is mandatory to determine the role and timing of each treatment modality. An exhaustive review of the literature was performed using the PubMed database concerning the natural history of tumor growth and hearing loss in NF2 patients with vestibular schwannomas. Although some aspects of vestibular schwannoma natural history remain uncertain (pattern of tumor growth, mean tumor growth rate), factors influencing growth such as age at presentation and paracrine factors are well established. Studies focusing on the natural history of hearing have highlighted different patterns of hearing loss and the possible role of intralabyrinthine tumors. The polyclonality of vestibular schwannomas in NF2 was recently unveiled, giving a new perspective to their growth mechanisms. An uniform evaluation of tumor growth using volumetric evaluation and hearing with standard classifications will ensure the use of common endpoints and should improve the quality of clinical trials as well as foster comparison among studies while ensuring more consistency in decision-making. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

The Mushroom Curriculum: Using Natural History to Teach Psychology.

Science.gov (United States)

Sommer, Robert

1989-01-01

Describes the development and content of a freshman seminar titled "The Psychology of Mushrooms," which teaches psychology as natural history. This approach allowed the course to proceed from concrete experience to general principals of perception, learning, social, and abnormal psychology. (Author/LS)

Nodding syndrome: origins and natural history of a longstanding ...

African Journals Online (AJOL)

Nodding syndrome: origins and natural history of a longstanding epileptic disorder in sub-Saharan Africa. ... Conclusion: Historical accounts of head nodding (amesinzia kichwa, Swahili) among the Wapogoro tribe fit the August 2012 World Health Organization (WHO) case definition of probable Nodding Syndrome.

Natural history of succinic semialdehyde dehydrogenase deficiency through adulthood

NARCIS (Netherlands)

Lapalme-Remis, S.; Lewis, E.C.; De Meulemeester, C.; Chakraborty, P.; Gibson, K.M.; Torres, C.; Guberman, A.; Salomons, G.; Jakobs, C.; Ali-Ridha, A.; Parviz, M.; Pearl, P.L.

2015-01-01

Objective: The natural history of succinic semialdehyde dehydrogenase (SSADH) deficiency in adulthood is unknown; we elucidate the clinical manifestations of the disease later in life. Methods: A 63-year-old man with long-standing intellectual disability was diagnosed with SSADH deficiency following

The association between harm avoidance personality traits and self-reported concussion history in South African rugby union players.

Science.gov (United States)

Mc Fie, Sarah; Abrahams, Shameemah; Patricios, Jon; Suter, Jason; Posthumus, Michael; September, Alison V

2018-01-01

Personality traits have been proposed to affect the risk of sports concussion, but evidence is limited. Cloninger's Tridimensional Personality Questionnaire (TPQ) measures novelty seeking, harm avoidance (HA), and reward dependence traits. The aim of this study was to investigate the relationship between TPQ scores and concussion history in rugby union players. Cross-sectional study. Rugby players from high schools, senior amateur clubs, and professional teams provided a self-reported concussion history and completed the TPQ. Participants reporting no previous concussions formed the control group, while participants reporting concussion formed the case group. A one-way analysis of covariance, with age as a covariate, was used to examine the differences in TPQ scores between groups. Of the 309 participants, 54% reported a minimum of one concussion (junior: 47%; amateur: 52%; professional: 72%). HA scores were significantly higher in junior players without a history of concussion compared to cases (p=0.006). Specifically, the junior control group had higher "anticipatory worry" (p=0.009) and "fear of uncertainty" (p=0.008). In contrast, the professional control group had lower HA scores than cases (p=0.009), while the amateur cohort displayed no differences between control and case groups. This study identified a novel association between HA and concussion in rugby players, adding evidence to the role of personality in a multifactorial risk-model of concussion. The findings suggest that lower HA may lead to increased dangerous play in youth rugby, influencing concussion susceptibility. Contrasting associations in the professional cohort suggest further research is required to understand the role of personality in concussion. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Representations of Nature of Science in Selected Histories of Science in

Science.gov (United States)

Wei, Bing; Li, Yue; Chen, Bo

2013-01-01

This study aimed to examine the representations of nature of science (NOS) in the eight histories of science selected from three series of integrated science textbooks used in junior high school in China. Ten aspects of NOS were adopted in the analytical framework. It was found that NOS had not been well treated in the selected histories of…

Contributions of dynamic environmental signals during life-cycle transitions to early life-history traits in lodgepole pine (Pinus contorta Dougl.)

Science.gov (United States)

Liu, Yang; Wang, Tongli; El-Kassaby, Yousry A.

2016-05-01

Environmental signals are important triggers in the life-cycle transitions and play a crucial role in the life-history evolution. Yet very little is known about the leading ecological factors contributing to the variations of life-history traits in perennial plants. This paper explores both the causes and consequences for the evolution of life-history traits (i.e., seed dormancy and size) in lodgepole pine (Pinus contorta Dougl.) across British Columbia (B.C.), Canada. We selected 83 logepole pine populations covering 22 ecosystem zones of B.C. and through their geographic coordinate, 197 climatic variables were generated accordingly for the reference (1961-1990) and future (2041-2070) periods. We found that dynamic climatic variables rather than constant geographic variables are the true environmental driving forces in seed dormancy and size variations and thus provide reliable predictors in response to global climate change. Evapotranspiration and precipitation in the plant-to-seed chronology are the most critical climate variables for seed dormancy and size variations, respectively. Hence, we predicted that levels of seed dormancy in lodgepole pine would increase across large tracts of B.C. in 2050s. Winter-chilling is able to increase the magnitude of life-history plasticity and lower the bet-hedge strategy in the seed-to-plant transition; however, winter-chilling is likely to be insufficient in the north of 49° N in 2050s, which may delay germination while unfavorable conditions during dry summers may result in adverse consequences in the survival of seedlings owing to extended germination span. These findings provide useful information to studies related to assessments of seed transfer and tree adaptation.

Reproductive ecology and early life history traits of the brooding coral, Porites astreoides, from shallow to mesophotic zones

Science.gov (United States)

Goodbody-Gringley, Gretchen; Wong, Kevin H.; Becker, Danielle M.; Glennon, Keegan; de Putron, Samantha J.

2018-06-01

Early life history traits of brooding corals are often affected by the environmental conditions experienced by parental colonies. Such parental effects can impact offspring survival, which influences the overall success of a population as well as resilience to environmental challenges. This study examines the reproductive ecology and early life history traits of the brooding coral Porites astreoides across a depth gradient in Bermuda. Fecundity, larval size, larval Symbiodinium density, and settlement success, as well as post-metamorphic juvenile survival, growth, and Symbiodinium density were compared across three reef sites representing an inshore patch reef (2-5 m), an offshore rim reef (8-10 m), and an upper-mesophotic reef (30-33 m). Although fecundity did not differ across sites, larvae produced by colonies on the patch reef site were smaller, had lower Symbiodinium densities, and had lower rates of settlement and juvenile survival compared to larvae from colonies on the rim and upper-mesophotic reef sites. Larvae produced by colonies from the rim and upper-mesophotic sites did not differ in size or Symbiodinium densities; however, rates of settlement, growth, and survival were higher for larvae from the upper-mesophotic site compared to those from the rim reef site. These results indicate that offspring quality and success vary among sites with differing environmental conditions and may imply higher recruitment potential and resilience for upper-mesophotic corals.

Can soil microbial diversity influence plant metabolites and life history traits of a rhizophagous insect? A demonstration in oilseed rape.

Science.gov (United States)

Lachaise, Tom; Ourry, Morgane; Lebreton, Lionel; Guillerm-Erckelboudt, Anne-Yvonne; Linglin, Juliette; Paty, Chrystelle; Chaminade, Valérie; Marnet, Nathalie; Aubert, Julie; Poinsot, Denis; Cortesero, Anne-Marie; Mougel, Christophe

2017-12-01

Interactions between plants and phytophagous insects play an important part in shaping the biochemical composition of plants. Reciprocally plant metabolites can influence major life history traits in these insects and largely contribute to their fitness. Plant rhizospheric microorganisms are an important biotic factor modulating plant metabolites and adaptation to stress. While plant-insects or plant-microorganisms interactions and their consequences on the plant metabolite signature are well-documented, the impact of soil microbial communities on plant defenses against phytophagous insects remains poorly known. In this study, we used oilseed rape (Brassica napus) and the cabbage root fly (Delia radicum) as biological models to tackle this question. Even though D. radicum is a belowground herbivore as a larva, its adult life history traits depend on aboveground signals. We therefore tested whether soil microbial diversity influenced emergence rate and fitness but also fly oviposition behavior, and tried to link possible effects to modifications in leaf and root metabolites. Through a removal-recolonization experiment, 3 soil microbial modalities ("high," "medium," "low") were established and assessed through amplicon sequencing of 16S and 18S ribosomal RNA genes. The "medium" modality in the rhizosphere significantly improved insect development traits. Plant-microorganism interactions were marginally associated to modulations of root metabolites profiles, which could partly explain these results. We highlighted the potential role of plant-microbial interaction in plant defenses against Delia radicum. Rhizospheric microbial communities must be taken into account when analyzing plant defenses against herbivores, being either below or aboveground. © 2017 Institute of Zoology, Chinese Academy of Sciences.

PHENOTYPIC DIFFERENTIATION AT SOUTHERN LIMIT BORDERS: THE CASE STUDY OF TWO FUCOID MACROALGAL SPECIES WITH DIFFERENT LIFE-HISTORY TRAITS1.

Science.gov (United States)

Araújo, Rita; Serrão, Ester A; Sousa-Pinto, Isabel; Åberg, Per

2011-06-01

Marginal populations are often geographically isolated, smaller, and more fragmented than central populations and may frequently have to face suboptimal local environmental conditions. Persistence of these populations frequently involves the development of adaptive traits at phenotypic and genetic levels. We compared population structure and demographic variables in two fucoid macroalgal species contrasting in patterns of genetic diversity and phenotypic plasticity at their southern distribution limit with a more central location. Models were Ascophyllum nodosum (L.) Le Jol. (whose extreme longevity and generation overlap may buffer genetic loss by drift) and Fucus serratus L. (with low genetic diversity at southern margins). At edge locations, both species exhibited trends in life-history traits compatible with population persistence but by using different mechanisms. Marginal populations of A. nodosum had higher reproductive output in spite of similar mortality rates at all life stages, making edge populations denser and with smaller individuals. In F. serratus, rather than demographic changes, marginal populations differed in habitat, occurring restricted to a narrower vertical habitat range. We conclude that persistence of both A. nodosum and F. serratus at the southern-edge locations depends on different strategies. Marginal population persistence in A. nodosum relies on a differentiation in life-history traits, whereas F. serratus, putatively poorer in evolvability potential, is restricted to a narrower vertical range at border locations. These results contribute to the general understanding of mechanisms that lead to population persistence at distributional limits and to predict population resilience under a scenario of environmental change. © 2011 Phycological Society of America.

Short history of natural product research in the CSIR

CSIR Research Space (South Africa)

Walwyn, D

2006-02-01

Full Text Available Natural product research has been a major component of the CSIR's bioscience activities for its entire history, and particularly in the 1960s and 1970s. This type of work is also strongly aligned with one of the objectives of the CSIR, namely...

Psoriasis: epidemiology, natural history, and differential diagnosis

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Basko-Plluska JL

2012-09-01

Full Text Available Juliana L Basko-Plluska, Vesna Petronic-RosicDepartment of Medicine, Section of Dermatology, University of Chicago, Chicago, IL, USAAbstract: Psoriasis is a chronic, immune-mediated, inflammatory disease which affects primarily the skin and joints. It occurs worldwide, but its prevalence varies considerably between different regions of the world. Genetic susceptibility as well as environmental factors play an important role in determining the development and prognosis of psoriasis. Genome-wide association studies have identified many genetic loci as potential psoriasis susceptibility regions, including PSORS1 through PSORS7. Histocompatibility antigen (HLA studies have also identified several HLA antigens, with HLA-Cw6 being the most frequently associated antigen. Epidemiological studies identified several modifiable risk factors that may predispose individuals to developing psoriasis or exacerbate pre-existing disease. These include smoking, obesity, alcohol consumption, diet, infections, medications and stressful life events. The exact mechanism by which they trigger psoriasis remains to be elucidated; however, existing data suggest that they are linked through Th1-mediated immunological pathways. The natural history of psoriasis varies depending on the clinical subtype as well as special circumstances, including pregnancy and HIV infection. In general, psoriasis is a chronic disease with intermittent remissions and exacerbations. The differential diagnosis is vast and includes many other immune-mediated, inflammatory disorders.Keywords: psoriasis, epidemiology, natural history, differential diagnosis

Niche-driven evolution of metabolic and life-history strategies in natural and domesticated populations of Saccharomyces cerevisiae

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Sicard Delphine

2009-12-01

Full Text Available Abstract Background Variation of resource supply is one of the key factors that drive the evolution of life-history strategies, and hence the interactions between individuals. In the yeast Saccharomyces cerevisiae, two life-history strategies related to different resource utilization have been previously described in strains from different industrial origins. In this work, we analyzed metabolic traits and life-history strategies in a broader collection of yeast strains sampled in various ecological niches (forest, human body, fruits, laboratory and industrial environments. Results By analysing the genetic and plastic variation of six life-history and three metabolic traits, we showed that S. cerevisiae populations harbour different strategies depending on their ecological niches. On one hand, the forest and laboratory strains, referred to as extreme "ants", reproduce quickly, reach a large carrying capacity and a small cell size in fermentation, but have a low reproduction rate in respiration. On the other hand, the industrial strains, referred to as extreme "grasshoppers", reproduce slowly, reach a small carrying capacity but have a big cell size in fermentation and a high reproduction rate in respiration. "Grasshoppers" have usually higher glucose consumption rate than "ants", while they produce lower quantities of ethanol, suggesting that they store cell resources rather than secreting secondary products to cross-feed or poison competitors. The clinical and fruit strains are intermediate between these two groups. Conclusions Altogether, these results are consistent with a niche-driven evolution of S. cerevisiae, with phenotypic convergence of populations living in similar habitat. They also revealed that competition between strains having contrasted life-history strategies ("ants" and "grasshoppers" seems to occur at low frequency or be unstable since opposite life-history strategies appeared to be maintained in distinct ecological niches.

The adaptive value of morphological, behavioural and life-history traits in reproductive female wolves.

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Stahler, Daniel R; MacNulty, Daniel R; Wayne, Robert K; vonHoldt, Bridgett; Smith, Douglas W

2013-01-01

Reproduction in social organisms is shaped by numerous morphological, behavioural and life-history traits such as body size, cooperative breeding and age of reproduction, respectively. Little is known, however, about the relative influence of these different types of traits on reproduction, particularly in the context of environmental conditions that determine their adaptive value. Here, we use 14 years of data from a long-term study of wolves (Canis lupus) in Yellowstone National Park, USA, to evaluate the relative effects of different traits and ecological factors on the reproductive performance (litter size and survival) of breeding females. At the individual level, litter size and survival improved with body mass and declined with age (c. 4-5 years). Grey-coloured females had more surviving pups than black females, which likely contributed to the maintenance of coat colour polymorphism in this system. The effect of pack size on reproductive performance was nonlinear as litter size peaked at eight wolves and then declined, and litter survival increased rapidly up to three wolves, beyond which it increased more gradually. At the population level, litter size and survival decreased with increasing wolf population size and canine distemper outbreaks. The relative influence of these different-level factors on wolf reproductive success followed individual > group > population. Body mass was the primary determinant of litter size, followed by pack size and population size. Body mass was also the main driver of litter survival, followed by pack size and disease. Reproductive gains because of larger body size and cooperative breeding may mitigate reproductive losses because of negative density dependence and disease. These findings highlight the adaptive value of large body size and sociality in promoting individual fitness in stochastic and competitive environments. © 2012 The Authors. Journal of Animal Ecology © 2012 British Ecological Society.

Trait-based prediction of extinction risk of small-bodied freshwater fishes.

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Kopf, R Keller; Shaw, Casey; Humphries, Paul

2017-06-01

Small body size is generally correlated with r-selected life-history traits, including early maturation, short-generation times, and rapid growth rates, that result in high population turnover and a reduced risk of extinction. Unlike other classes of vertebrates, however, small freshwater fishes appear to have an equal or greater risk of extinction than large fishes. We explored whether particular traits explain the International Union for Conservation of Nature (IUCN) Red List conservation status of small-bodied freshwater fishes from 4 temperate river basins: Murray-Darling, Australia; Danube, Europe; Mississippi-Missouri, North America; and the Rio Grande, North America. Twenty-three ecological and life-history traits were collated for all 171 freshwater fishes of ≤120 mm total length. We used generalized linear mixed-effects models to assess which combination of the 23 traits best explained whether a species was threatened or not threatened. We used the best models to predict the probability of 29 unclassified species being listed as threatened. With and without controlling for phylogeny at the family level, small body size-among small-bodied species-was the most influential trait correlated with threatened species listings. The k-folds cross-validation demonstrated that body size and a random effect structure that included family predicted the threat status with an accuracy of 78% (SE 0.5). We identified 10 species likely to be threatened that are not listed as such on the IUCN Red List. Small body size is not a trait that provides universal resistance to extinction, particularly for vertebrates inhabiting environments affected by extreme habitat loss and fragmentation. We hypothesize that this is because small-bodied species have smaller home ranges, lower dispersal capabilities, and heightened ecological specialization relative to larger vertebrates. Trait data and further model development are needed to predict the IUCN conservation status of the over 11

Life-History Traits of the Model Organism Pristionchus pacificus Recorded Using the Hanging Drop Method: Comparison with Caenorhabditis elegans.

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Gilarte, Patricia; Kreuzinger-Janik, Bianca; Majdi, Nabil; Traunspurger, Walter

2015-01-01

The nematode Pristionchus pacificus is of growing interest as a model organism in evolutionary biology. However, despite multiple studies of its genetics, developmental cues, and ecology, the basic life-history traits (LHTs) of P. pacificus remain unknown. In this study, we used the hanging drop method to follow P. pacificus at the individual level and thereby quantify its LHTs. This approach allowed direct comparisons with the LHTs of Caenorhabditis elegans recently determined using this method. When provided with 5×10(9) Escherichia coli cells ml(-1) at 20°C, the intrinsic rate of natural increase of P. pacificus was 1.125 (individually, per day); mean net production was 115 juveniles produced during the life-time of each individual, and each nematode laid an average of 270 eggs (both fertile and unfertile). The mean age of P. pacificus individuals at first reproduction was 65 h, and the average life span was 22 days. The life cycle of P. pacificus is therefore slightly longer than that of C. elegans, with a longer average life span and hatching time and the production of fewer progeny.

Life-History Traits of the Model Organism Pristionchus pacificus Recorded Using the Hanging Drop Method: Comparison with Caenorhabditis elegans.

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Patricia Gilarte

Full Text Available The nematode Pristionchus pacificus is of growing interest as a model organism in evolutionary biology. However, despite multiple studies of its genetics, developmental cues, and ecology, the basic life-history traits (LHTs of P. pacificus remain unknown. In this study, we used the hanging drop method to follow P. pacificus at the individual level and thereby quantify its LHTs. This approach allowed direct comparisons with the LHTs of Caenorhabditis elegans recently determined using this method. When provided with 5×10(9 Escherichia coli cells ml(-1 at 20°C, the intrinsic rate of natural increase of P. pacificus was 1.125 (individually, per day; mean net production was 115 juveniles produced during the life-time of each individual, and each nematode laid an average of 270 eggs (both fertile and unfertile. The mean age of P. pacificus individuals at first reproduction was 65 h, and the average life span was 22 days. The life cycle of P. pacificus is therefore slightly longer than that of C. elegans, with a longer average life span and hatching time and the production of fewer progeny.

Does thermal variability experienced at the egg stage influence life history traits across life cycle stages in a small invertebrate?

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Kun Xing

Full Text Available Although effects of thermal stability on eggs have often been considered in vertebrates, there is little data thermal stability in insect eggs even though these eggs are often exposed in nature to widely fluctuating ambient conditions. The modularity of development in invertebrates might lead to compensation across life cycle stages but this remains to be tested particularly within the context of realistic temperature fluctuations encountered in nature. We simulated natural temperate fluctuations on eggs of the worldwide cruciferous insect pest, the diamondback moth (DBM, Plutella xylostella (L., while maintaining the same mean temperature (25°C±0°C, 25±4°C, 25±6°C, 25±8°C, 25±10°C, 25±12°C and assessed egg development, survival and life history traits across developmental stages. Moderate fluctuations (25±4°C, 25±6°C did not influence performance compared to the constant temperature treatment, and none of the treatments influenced egg survival. However the wide fluctuating temperatures (25±10°C, 25±12°C slowed development time and led to an increase in pre-pupal mass, although these changes did not translate into any effects on longevity or fecundity at the adult stage. These findings indicate that environmental effects can extend across developmental stages despite the modularity of moth development but also highlight that there are few fitness consequences of the most variable thermal conditions likely to be experienced by Plutella xylostella.

Evolution of larval competitiveness and associated life-history traits in response to host shifts in a seed beetle.

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Fox, C W; Messina, F J

2018-02-01

Resource competition is frequently strong among parasites that feed within small discrete resource patches, such as seeds or fruits. The properties of a host can influence the behavioural, morphological and life-history traits of associated parasites, including traits that mediate competition within the host. For seed parasites, host size may be an especially important determinant of competitive ability. Using the seed beetle, Callosobruchus maculatus, we performed replicated, reciprocal host shifts to examine the role of seed size in determining larval competitiveness and associated traits. Populations ancestrally associated with either a small host (mung bean) or a large one (cowpea) were switched to each other's host for 36 generations. Compared to control lines (those remaining on the ancestral host), lines switched from the small host to the large host evolved greater tolerance of co-occurring larvae within seeds (indicated by an increase in the frequency of small seeds yielding two adults), smaller egg size and higher fecundity. Each change occurred in the direction predicted by the traits of populations already adapted to cowpea. However, we did not observe the expected decline in adult mass following the shift to the larger host. Moreover, lines switched from the large host (cowpea) to the small host (mung bean) did not evolve the predicted increase in larval competitiveness or egg size, but did exhibit the predicted increase in body mass. Our results thus provide mixed support for the hypothesis that host size determines the evolution of competition-related traits of seed beetles. Evolutionary responses to the two host shifts were consistent among replicate lines, but the evolution of larval competition was asymmetric, with larval competitiveness evolving as predicted in one direction of host shift, but not the reverse. Nevertheless, our results indicate that switching hosts is sufficient to produce repeatable and rapid changes in the competition strategy

Generalist-specialist continuum and life history traits of Central European butterflies (Lepidoptera) – are we missing a part of the picture?

Czech Academy of Sciences Publication Activity Database

Bartoňová, Alena; Beneš, Jiří; Konvička, Martin

2014-01-01

Roč. 111, č. 4 (2014), s. 543-553 ISSN 1210-5759 R&D Projects: GA ČR GAP505/10/2167 Grant - others:GA JU(CZ) 650/3115 Institutional support: RVO:60077344 Keywords : Lepidoptera * Czech butterflies * life history traits Subject RIV: EH - Ecology, Behaviour Impact factor: 0.975, year: 2014 http://www.eje.cz/pdfs/eje/2014/04/12.pdf

Natural history of breast cancers detected in the Swedish mammography screening programme: a cohort study

DEFF Research Database (Denmark)

Zahl, Per-Henrik; Gøtzsche, Peter C; Mæhlen, Jan

2011-01-01

The natural history of screen-detected breast cancers is not well understood. A previous analysis of the incidence change during the introduction of the Norwegian screening programme in the late 1990s suggested that the natural history of many screen-detected invasive breast cancers is to regress...

Body linear traits for identifying prolific goats

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Avijit Haldar

2014-12-01

Full Text Available Aim: The present study was conducted on prolific goat breed to identify body linear type traits that might be associated with prolificacy trait in goats. Materials and Methods: Two-stage stratified random sample survey based data were collected from 1427 non-pregnant goats with the history of single, twin and triplet litter sizes (LZ between January 2008 to February 2011 for 3 years in 68 villages located in East and North East India. Data on sixteen body linear traits were analyzed using logistic regression model to do the step-wise selection for identifying the body linear traits that could determine LZ. An average value for each identified body linear trait was determined for classifying the goats into three categories: Goats having the history of single LZ, goats having the history of twin LZ and goats having the history of triplet LZ. Results: The LZ proportions for single, twin and triplet, were 29.50, 59.14 and 11.36%, respectively, with the prolificacy rate of 181.85% in Indian Black Bengal goats. A total of eight body linear traits that could determine LZ in prolific goats were identified. Heart girth (HG measurement (>60.90 cm, paunch girth (PG (>70.22 cm, wither height (WH (>49.75 cm, neck length (>21.45 cm, ear length (>12.80 cm and distance between trochanter major (DTM bones (>12.28 cm, pelvic triangle area (PTA (>572.25 cm2 and clearance at udder (CU (>23.16 cm showed an increase likelihood of multiple LZ when compared to single LZ. Further, HG measurement (>62.29 cm, WH (>50.54 cm, PG (>71.85 cm and ear length (>13.00 cm, neck length (>22.01 cm, PTA (>589.64 cm2, CU (>23.20 cm and DTM bones (>12.47 cm were associated with increased likelihood of triplet LZ, when compared with that of twin LZ. Conclusion: HG measurement was the best discriminating factor, while PG, neck length, DTM bones, CU, PTA, WH and ear length measurements were other important factors that could be used for identifying prolific goats to achieve economic

Gaucher Disease: The Metabolic Defect, Pathophysiology, Phenotypes And Natural History

Science.gov (United States)

Baris, Hagit N.; Cohen, Ian J.; Mistry, Pramod K.

2015-01-01

Gaucher disease (GD), a prototype lysosomal storage disorder, results from inherited deficiency of lysosomal glucocerebrosidase due to biallelic mutations in GBA. The result is widespread accumulation of macrophages engorged with predominantly lysosomal glucocerebroside. A complex multisystem phenotype arises involving the liver, spleen, bone marrow and occasionally the lungs in type 1 Gaucher disease; in neuronopathic fulminant type 2 and chronic type 3 disease there is in addition progressive neurodegenerative disease. Manifestations of Gaucher disease type 1 (GD1) include hepatosplenomegaly, cytopenia, a complex pattern of bone involvement with avascular osteonecrosis (AVN), osteoporosis, fractures and lytic lesions. Enzyme replacement therapy became the standard of care in 1991, and this has transformed the natural history of GD1. This article reviews the clinical phenotypes of GD, diagnosis, pathophysiology and its natural history. A subsequent chapter discusses the treatment options. PMID:25345088

[Natural history, complications, safety and pregnancy in inflammatory bowel disease].

Science.gov (United States)

Chaparro, María

2015-09-01

Numerous studies were presented in Digestive Disease Week 2015 (DDW 2015) on the natural history, complications, and safety of treatments in inflammatory bowel disease (IBD), as well as novel findings on fertility, pregnancy, and breastfeeding. The present article reviews presentations on the natural history of IBD, the risk of complications and their prevention, treatment safety, aspects related to fertility, pregnancy, and breastfeeding, as well as the risk of cancer and its association with IBD and with drugs used in its treatment. In the next few years, more data will become available on treatment safety and the possible complications that can develop in IBD patients due to the disease itself and the drugs employed in its treatment, which will allow measures to be adopted to improve prognosis. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

A three-genome phylogeny of malaria parasites (Plasmodium and closely related genera): evolution of life-history traits and host switches.

Science.gov (United States)

Martinsen, Ellen S; Perkins, Susan L; Schall, Jos J

2008-04-01

Phylogenetic analysis of genomic data allows insights into the evolutionary history of pathogens, especially the events leading to host switching and diversification, as well as alterations of the life cycle (life-history traits). Hundreds, perhaps thousands, of malaria parasite species exploit squamate reptiles, birds, and mammals as vertebrate hosts as well as many genera of dipteran vectors, but the evolutionary and ecological events that led to this diversification and success remain unresolved. For a century, systematic parasitologists classified malaria parasites into genera based on morphology, life cycle, and vertebrate and insect host taxa. Molecular systematic studies based on single genes challenged the phylogenetic significance of these characters, but several significant nodes were not well supported. We recovered the first well resolved large phylogeny of Plasmodium and related haemosporidian parasites using sequence data for four genes from the parasites' three genomes by combining all data, correcting for variable rates of substitution by gene and site, and using both Bayesian and maximum parsimony analyses. Major clades are associated with vector shifts into different dipteran families, with other characters used in traditional parasitological studies, such as morphology and life-history traits, having variable phylogenetic significance. The common parasites of birds now placed into the genus Haemoproteus are found in two divergent clades, and the genus Plasmodium is paraphyletic with respect to Hepatocystis, a group of species with very different life history and morphology. The Plasmodium of mammal hosts form a well supported clade (including Plasmodium falciparum, the most important human malaria parasite), and this clade is associated with specialization to Anopheles mosquito vectors. The Plasmodium of birds and squamate reptiles all fall within a single clade, with evidence for repeated switching between birds and squamate hosts.

Trait-specific processes of convergence and conservatism shape ecomorphological evolution in ground-dwelling squirrels.

Science.gov (United States)

McLean, Bryan S; Helgen, Kristofer M; Goodwin, H Thomas; Cook, Joseph A

2018-03-01

Our understanding of mechanisms operating over deep timescales to shape phenotypic diversity often hinges on linking variation in one or few trait(s) to specific evolutionary processes. When distinct processes are capable of similar phenotypic signatures, however, identifying these drivers is difficult. We explored ecomorphological evolution across a radiation of ground-dwelling squirrels whose history includes convergence and constraint, two processes that can yield similar signatures of standing phenotypic diversity. Using four ecologically relevant trait datasets (body size, cranial, mandibular, and molariform tooth shape), we compared and contrasted variation, covariation, and disparity patterns in a new phylogenetic framework. Strong correlations existed between body size and two skull traits (allometry) and among skull traits themselves (integration). Inferred evolutionary modes were also concordant across traits (Ornstein-Uhlenbeck with two adaptive regimes). However, despite these broad similarities, we found divergent dynamics on the macroevolutionary landscape, with phenotypic disparity being differentially shaped by convergence and conservatism. Such among-trait heterogeneity in process (but not always pattern) reiterates the mosaic nature of morphological evolution, and suggests ground squirrel evolution is poorly captured by single process descriptors. Our results also highlight how use of single traits can bias macroevolutionary inference, affirming the importance of broader trait-bases in understanding phenotypic evolutionary dynamics. © 2018 The Author(s). Evolution © 2018 The Society for the Study of Evolution.

A unified framework for diversity gradients : The adaptive trait continuum

NARCIS (Netherlands)

Carnicer, Jofre; Stefanescu, Constanti; Vila, Roger; Dinca, Vlad; Font, Xavier; Penuelas, Josep

Aim Adaptive trait continua are axes of covariation observed in multivariate trait data for a given taxonomic group. These continua quantify and summarize life-history variation at the inter-specific level in multi-specific assemblages. Here we examine whether trait continua can provide a useful

Production traits of artificially and naturally hatched geese in intensive and free-range systems: I. Growth traits.

Science.gov (United States)

Boz, M A; Sarica, M; Yamak, U S

2017-04-01

1. This study investigated the effect of incubation type and production system on geese growth traits. 2. A total of 216 geese were either naturally (114) or artificially (102) hatched and reared in intensive or free-range production systems (4 replicates each) until 18 weeks of age. 3. Weights of naturally hatched goslings (NHG) were significantly higher than artificially hatched goslings (AHG) at 2 weeks (644 vs. 536 g); however, weights of AHG were significantly higher than NHG at both 6 weeks (3245 vs. 3010 g) and 18 weeks (5212 vs. 4353 g). 4. AHG had better feed conversion ratios (FCRs) than NHG (6.21 vs. 6.46 at 18 weeks). Feed consumption of naturally hatched geese was found higher in first 4 weeks when compared to artificially hatched geese and artificially hatched geese consumed more feed than naturally hatched geese after 8 weeks. 5. Production system had insignificant effects on feed consumption, FCRs, viability and mutilation rates. 6. Slipped wings were more frequent in NHG than AHG (8.32% vs. 1.68% at 6 weeks; 23.84% vs. 5.12% between 7 and 18 weeks) and in free-range production when compared to intensive production (17.88% vs. 11.08% over the course of the production period). 7. The study results indicate that both artificially and NHG can be reared in free-range production systems without any loss in performance and in deference to animal welfare.

Life-History Patterns of Lizards of the World.

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Mesquita, Daniel O; Costa, Gabriel C; Colli, Guarino R; Costa, Taís B; Shepard, Donald B; Vitt, Laurie J; Pianka, Eric R

2016-06-01

Identification of mechanisms that promote variation in life-history traits is critical to understand the evolution of divergent reproductive strategies. Here we compiled a large life-history data set (674 lizard populations, representing 297 species from 263 sites globally) to test a number of hypotheses regarding the evolution of life-history traits in lizards. We found significant phylogenetic signal in most life-history traits, although phylogenetic signal was not particularly high. Climatic variables influenced the evolution of many traits, with clutch frequency being positively related to precipitation and clutches of tropical lizards being smaller than those of temperate species. This result supports the hypothesis that in tropical and less seasonal climates, many lizards tend to reproduce repeatedly throughout the season, producing smaller clutches during each reproductive episode. Our analysis also supported the hypothesis that viviparity has evolved in lizards as a response to cooler climates. Finally, we also found that variation in trait values explained by clade membership is unevenly distributed among lizard clades, with basal clades and a few younger clades showing the most variation. Our global analyses are largely consistent with life-history theory and previous results based on smaller and scattered data sets, suggesting that these patterns are remarkably consistent across geographic and taxonomic scales.

Selection for life-history traits to maximize population growth in an invasive marine species

DEFF Research Database (Denmark)

Jaspers, Cornelia; Marty, Lise; Kiørboe, Thomas

2018-01-01

Species establishing outside their natural range, negatively impacting local ecosystems, are of increasing global concern. They often display life-history features characteristic for r-selected populations with fast growth and high reproduction rates to achieve positive population growth rates (r...

Selected personality traits and achievement motivation in university students of physical culture, education and natural sciences

Directory of Open Access Journals (Sweden)

Martin Sigmund

2013-09-01

Full Text Available BACKGROUND: Understanding personality variables and other important psychological traits in the university population appears topical particularly with respect to personality, motivation, health as well as overall academic achievement. A significant role is played by correlations of the monitored variables in relation to selected study specialization. OBJECTIVE: The main objective of the present study is to extend the knowledge on selected personality traits and the level of achievement motivation in a specific group of university students with respect to the diversity of their study specialization. METHODS: The study included a total of 522 students from Palacký University. These were students from the Faculty of Physical Culture (n = 118, Faculty of Education (n = 218 and Faculty of Science (n = 186. In terms of age, the study focused on young adults aged 19 to 26. In the research, psychodiagnostic methods were used to perform diagnostics and to fulfil the overall research plan. All diagnostic methods used are fully standardized and contain domestic normative values. We monitored variables such as personality, achievement motivation and achievement anxiety. Statistical result processing was conducted using the Statgraphics programme v. 9.0. Result processing was made using parametric as well as non-parametric statistical methods (Shapiro-Wilk, Mann-Whitney, Kruskal-Wallis, Spearman’s correlation. RESULTS: University students specialized in physical culture showed the highest values of extraversion and psychoticism, and clearly the lowest values of neuroticism compared to the students of education and natural sciences. The highest values of openness were observed in the students specialized in sports. In terms of the overall achievement motivation related to study specialization, almost identical values were observed. However, the students of physical culture showed significantly lower values of achievement debilitating anxiety

On the fate of sexual traits under asexuality

NARCIS (Netherlands)

van der Kooi, Casper J; Schwander, Tanja

2014-01-01

Environmental shifts and life-history changes may result in formerly adaptive traits becoming non-functional or maladaptive. In the absence of pleiotropy and other constraints, such traits may decay as a consequence of neutral mutation accumulation or selective processes, highlighting the importance

History as narrative: the nature and quality of historical understanding for students with LD.

Science.gov (United States)

Espin, Christine A; Cevasco, Jazmin; van den Broek, Paul; Baker, Scott; Gersten, Russell

2007-01-01

In this study, we examine the nature and quality of students' comprehension of history. Specifically, we explore whether cognitive-psychological theories developed to capture the comprehension of narrative text can be used to capture the comprehension of history. Participants were 36 students with learning disabilities who had taken part in an earlier study designed to investigate the effects of an interactive instructional intervention in history. The results of the original study supported the effectiveness of the intervention in terms of amount recalled. The results of the present study reveal that historical understanding can be characterized as the construction of meaning through the creation of a causal network of events. The study of history within a causal network framework has implications for understanding the nature and quality of students' learning of history, and for potentially identifying sources of failure in learning.

The natural history of Perthes' disease.

Science.gov (United States)

Terjesen, Terje; Wiig, Ola; Svenningsen, Svein

2010-12-01

The prognosis in Perthes' disease varies considerably according to certain risk factors, but there is no concensus regarding the relative importance of these factors. We assessed the natural history of the disease and defined prognostic factors of value in deciding the proper treatment. During the 5-year period 1996-2000, a nationwide study on Perthes' disease was performed in Norway. 425 patients were registered. The present study involved the 212 children (mean age 5.1 years, 77% boys) who were affected unilaterally and who had been treated with physiotherapy only (which is considered not to change the natural history). They were followed by taking radiographs at the time of diagnosis and after 1, 3, and 5 years. At the 5-year follow-up, the outcome was evaluated according to a modification of the Stulberg classification: good (spherical femoral head), fair (ovoid femoral head), and poor (flat femoral head). The 5-year radiographic results were strongly dependent on 4 risk factors: age 6 years or more at diagnosis, total femoral head necrosis, height of the lateral pillar of the epiphysis less than 50% of normal height, and femoral head cover less than 80%. As the number of risk factors increased from 0 to 4, the proportion of patients with good radiographic 5-year outcome decreased from 79% to 0% and the proportion with poor outcome increased from 3% to 91%. Most children under 6 years of age do not need any special treatment. In older children, no special treatment is indicated if the whole femoral head is not necrotic and the femoral head cover is > 80%. In the most severe forms of the disease (i.e. more than 2 risk factors), surgical containment treatment seems advisable.

Nature and history today: the ecological crisis

Directory of Open Access Journals (Sweden)

Luciano ESPINOSA RUBIO

2012-02-01

Full Text Available Today, the Nature-History relations are the ecological ones: we are living in a global eco-bio-techno-noos-sphere and that means that ecological crisis is a crisis of civilization too. Above all, the climate change and its social and political consequences will have a great impact in our lives, and we must respond without losing our rights. In the intellectual way, we need new narrations in order to affront the situation and perhaps the theory of the lesser evil is one of the better answers that we can find.

Hypomanic personality traits in a community sample of adolescents.

Science.gov (United States)

Klein, D N; Lewinsohn, P M; Seeley, J R

1996-06-05

The distribution and correlates of hypomanic personality traits were examined in a representative sample of 1709 adolescents. Hypomanic traits were assessed with an abbreviated version of Eckblad and Chapman's (1986) Hypomanic Personality Scale. Hypomanic traits were normally distributed and were slightly but significantly higher among females. Test-retest stability over a mean 14-month interval was 0.54. High scores were associated with elevated lifetime rates of mood, disruptive behavior and substance use disorders. Among subjects with no history of mood disorder, hypomanic traits were associated with a broad range of indices of psychosocial dysfunction, both concurrently and at 1-year follow-up. In addition, hypomanic personality traits predicted increased levels of impairment in a number of areas, including depressive and internalizing symptomatology, over the course of the follow-up. Finally, among subjects with a past history of major depression, hypomanic traits were associated with a higher level of depression at the initial assessment, greater symptomatology and impairment during their worst episode, and higher rates of attempted suicide, comorbid disruptive behavior disorders and recurrent major depressive episodes.

Does history of childhood maltreatment make a difference in prison? A hierarchical approach on early family events and personality traits.

Science.gov (United States)

Sergentanis, Theodoros N; Sakelliadis, Emmanouil I; Vlachodimitropoulos, Dimitrios; Goutas, Nikolaos; Sergentanis, Ioannis N; Spiliopoulou, Chara A; Papadodima, StavroulaA

2014-12-30

This study attempts to assess childhood maltreatment in prison through a hierarchical approach. The hierarchical approach principally aims to disentangle the independent effects of childhood maltreatment upon psychiatric morbidity/personality traits, if any, from the burden that the adverse family conditions have already imposed to the mental health of the maltreated individual-prisoner. To this direction, a conceptual framework with five hierarchical levels was constructed, namely: immutable demographic factors; family conditions; childhood maltreatment (physical abuse, neglect and sexual abuse); personality traits, habits and psychiatric morbidity; prison-related variables. A self-administered, anonymous set (battery) of questionnaires was administered to 173 male prisoners in the Chalkida prison, Greece; 26% of prisoners disclosed childhood maltreatment. Psychiatric condition in the family, parental alcoholism and parental divorce correlated with childhood maltreatment. After adjustment for immutable demographic factors and family conditions, childhood maltreatment was associated with aggression (both in terms of Lifetime History of Aggression and Buss–Perry Aggression Questionnaire scores), illicit substance use, personal history of psychiatric condition, current smoking, impulsivity and alcohol abuse. In conclusion, childhood maltreatment represents a pivotal, determining factor in the life course of male prisoners. Delinquents seem to suffer from long-term consequences of childhood maltreatment in terms of numerous mental health aspects.

What can bioinformatics do for Natural History museums?

Directory of Open Access Journals (Sweden)

Becerra, José María

2003-06-01

Full Text Available We propose the founding of a Natural History bioinformatics framework, which would solve one of the main problems in Natural History: data which is scattered around in many incompatible systems (not only computer systems, but also paper ones. This framework consists of computer resources (hardware and software, methodologies that ease the circulation of data, and staff expert in dealing with computers, who will develop software solutions to the problems encountered by naturalists. This system is organized in three layers: acquisition, data and analysis. Each layer is described, and an account of the elements that constitute it given.

Se presentan las bases de una estructura bioinformática para Historia Natural, que trata de resolver uno de los principales problemas en ésta: la presencia de datos distribuidos a lo largo de muchos sistemas incompatibles entre sí (y no sólo hablamos de sistemas informáticos, sino también en papel. Esta estructura se sustenta en recursos informáticos (en sus dos vertientes: hardware y software, en metodologías que permitan la fácil circulación de los datos, y personal experto en el uso de ordenadores que se encargue de desarrollar soluciones software a los problemas que plantean los naturalistas. Este sistema estaría organizado en tres capas: de adquisición, de datos y de análisis. Cada una de estas capas se describe, indicando los elementos que la componen.

Natural history of Duchenne muscular dystrophy

Directory of Open Access Journals (Sweden)

Qing KE

2015-05-01

Full Text Available Duchenne muscular dystrophy (DMD is X-linked recessive hereditary disease. DMD gene mutations result in dystrophin deficiency, which causes not only muscle movement disorders but also scoliosis, cognitive dysfunction, urinary tract diseases, respiratory diseases and heart diseases. Most patients die in early adult for respiratory and circulatory failure. Early multidisciplinary therapies will significantly delay disease progression and improve patients' quality of life. However, DMD diagnosis and treatment exist significantly time delay now. In this study, we review the natural history of DMD, including motor, cognitive, respiratory and heart function, for improving DMD early recognition, diagnosis and treatment, so as to benefit DMD patients. DOI: 10.3969/j.issn.1672-6731.2015.05.004

CORE EXPERIMENTS, NATURAL HISTORIES AND THE ART OF EXPERIENTIA LITERATA: THE MEANING OF BACONIAN EXPERIMENTATION

Directory of Open Access Journals (Sweden)

Dana JALOBEANU

2011-11-01

Full Text Available Experiment, as a new form of knowledge, was aBaconian creation. It was in Bacon’s project of Great Instauration and inBacon’s reformed natural history that experiment and experimentationceased to be illustrations of theories and become relatively autonomousdevices for the production of knowledge and for setting the mind straightin its attempts to gain knowledge. This paper explores the way in whichBacon’s Latin natural history transformed experiment and experimentationin such devices. More precisely, I investigate the way in which Bacon’sLatin natural histories were put together from a limited number ofsignificant experiments listed in the Novum Organum under the general title“instances of special power” or “instances of the lamp.” Contrary to thereceived view, my claim is that Bacon’s natural histories are based on alimited number of ‘core experiments’ and are generated through a specificmethodological procedure known under the name of experientia literata. Thispaper is an attempt to reconstruct the procedure of putting such naturalhistories together and a more in-depth exploration of their epistemologicaland therapeutic character.

North American box turtles: A natural history

Science.gov (United States)

Dodd, C. Kenneth

2002-01-01

Once a familiar backyard visitor in many parts of the United States and Mexico, the box turtle is losing the battle against extinction. In North American Box Turtles, C. Kenneth Dodd, Jr., has written the first book-length natural history of the twelve species and subspecies of this endangered animal. This volume includes comprehensive information on the species’ evolution, behavior, courtship and reproduction, habitat use, diet, population structure, systematics, and disease. Special features include color photos of all species, subspecies, and their habitats; a simple identification guide to both living and fossil species; and a summary of information on fossil Terrapene and Native uses of box turtles. End-of-chapter sections highlight future research directions, including the need for long-term monitoring and observation of box turtles within their natural habitat and conservation applications. A glossary and a bibliography of literature on box turtles accompany the text.

What makes a successful species? Traits facilitating survival in altered tropical forests.

Science.gov (United States)

Hirschfeld, Mareike; Rödel, Mark-Oliver

2017-06-28

Ongoing conversion, disturbance and fragmentation of tropical forests stress this ecosystem and cause the decline or disappearance of many species. Particular traits have been identified which indicate an increasing extinction risk of a species, but traits facilitating survival in altered habitats have mostly been neglected. Here we search for traits that make a species tolerant to disturbances, thus independent of pristine forests. We identify the fauna that have an increasing effect on the ecosystem and its functioning in our human-dominated landscapes. We use a unique set of published data on the occurrences of 243 frog species in pristine and altered forests throughout the tropics. We established a forest dependency index with four levels, based on these occurrence data and applied Random Forest classification and binomial Generalized Linear Models to test whether species life history traits, ecological traits or range size influence the likelihood of a species to persist in disturbed habitats. Our results revealed that indirect developing species exhibiting a large range size and wide elevational distribution, being independent of streams, and inhabiting the leaf litter, cope best with modifications of their natural habitats. The traits identified in our study will likely persist in altered tropical forest systems and are comparable to those generally recognized for a low species extinction risk. Hence our findings will help to predict future frog communities in our human-dominated world.

Spinal tuberculosis, natural history of disease, classifications and principles of management with historical perspective.

Science.gov (United States)

Kumar, Kush

2016-08-01

To describe the natural history spinal tuberculosis, classifications and principles of management based upon the grading of the neurological deficit. Review of literature was conducted with the aim to provide the clinico-radiological correlation of the natural history of spinal tuberculosis in different stages. Management strategy is developed based upon the severity of the neurological deficit. A five stage natural history of spinal tuberculosis is described. Stage of neurological involvement is further divided into 4 grades, predominantly on the basis of progressively increasing motor deficits as negligible, mild, moderate and severe with sensory and autonomic dysfunctions. Suitable principles of management with role of rest, braces, chemotherapy and surgery are discussed. Neurological deficit grading based management is developed. Grade 1 and 2, conservative treatment, grade 3, gray zone and grade 4, operative treatment is emphasized. The five stages of natural history of tuberculosis of spine have been developed from the clinician's point of view. Management of tuberculosis of spine, in general, it is no different than management of soft tissue tuberculosis, in HIV negative or positive patients. Role of surgery is very limited. Management of tubercular paraplegia, based upon the grading of paraplegia is simple, logical, efficient and easy to understand and remember by any orthopedic surgeon.

Using large-scale data analysis to assess life history and behavioural traits: the case of the reintroduced White stork Ciconia ciconia population in the Netherlands

NARCIS (Netherlands)

Doligez, B.; Thomson, D.L.; Van Noordwijk, A.J.

2004-01-01

The White stork Ciconia ciconia has been the object of several successful reintroduction programmes in the last decades. As a consequence, populations have been monitored over large spatial scales. Despite these intense efforts, very few reliable estimates of life history traits are available for

How do different humanness measures relate? Confronting the attribution of secondary emotions, human uniqueness, and human nature traits.

Science.gov (United States)

Martínez, Rocío; Rodriguez-Bailon, Rosa; Moya, Miguel; Vaes, Jeroen

2017-01-01

The present research examines the relationship between the infrahumanization approach and the two-dimensional model of humanness: an issue that has received very little empirical attention. In Study 1, we created three unknown groups (Humanized, Animalized, and Mechanized) granting/denying them Human Nature (HN) and Human Uniqueness (HU) traits. The attribution of primary/secondary emotions was measured. As expected, participants attributed more secondary emotions to the humanized compared to dehumanized groups. Importantly, both animalized and mechanized groups were attributed similar amounts of secondary emotions. In Study 2, the groups were described in terms of their capacity to express secondary emotions. We measured the attribution of HN/HU traits. Results showed that the infrahumanized group was denied both HU/HN traits. The results highlight the importance of considering the common aspects of both approaches in understanding processes of dehumanization.

Assessing the effects of FBC ash treatments of metal-contaminated soils using life history traits and metal bioaccumulation analysis of the earthworm Eisenia andrei

Energy Technology Data Exchange (ETDEWEB)

Grumiaux, F.; Demuynck, S.; Schikorski, D.; Lemiere, S.; Lepretre, A. [Universite Lille Nord de France, Villeneuve Dascq (France)

2010-03-15

Earthworms (Eisenia andrei) were exposed, in controlled conditions, to metal-contaminated soils previously treated in situ with two types of fluidized bed combustion ashes. Effects on this species were determined by life history traits analysis. Metal immobilizing efficiency of ashes was indicated by metal bioaccumulation. Ashes-treated soils reduced worm mortality compared to the untreated soil. However, these ashes reduced both cocoon hatching success and hatchlings numbers compared to the untreated soil. In addition, sulfo-calcical ashes reduced or delayed worm maturity and lowered cocoon production compared to silico-alumineous ones. Metal immobilizing efficiency of ashes was demonstrated for Zn, Cu and to a lesser extent Pb. Only silico-alumineous ashes reduced Cd bioaccumulation, although Cd was still bioconcentrated. Thus, although ash additions to metal-contaminated soils may help in immobilizing metals, their use might result, depending on the chemical nature of ashes, to severe detrimental effects on earthworm reproduction with possible long term consequences to populations.

Herbivores sculpt leaf traits differently in grasslands depending on life form and land-use histories.

Science.gov (United States)

Firn, Jennifer; Schütz, Martin; Nguyen, Huong; Risch, Anita C

2017-01-01

Vertebrate and invertebrate herbivores alter plant communities directly by selectively consuming plant species; and indirectly by inducing morphological and physiological changes to plant traits that provide competitive or survivorship advantages to some life forms over others. Progressively excluding aboveground herbivore communities (ungulates, medium and small sized mammals, invertebrates) over five growing seasons, we explored how leaf morphology (specific leaf area or SLA) and nutrition (nitrogen, carbon, phosphorous, potassium, sodium, and calcium) of different plant life forms (forbs, legumes, grasses, sedges) correlated with their dominance. We experimented in two subalpine grassland types with different land-use histories: (1) heavily grazed, nutrient-rich, short-grass vegetation and (2) lightly grazed, lower nutrient tall-grass vegetation. We found differences in leaf traits between treatments where either all herbivores were excluded or all herbivores were present, showing the importance of considering the impacts of both vertebrates and invertebrates on the leaf traits of plant species. Life forms responses to the progressive exclusion of herbivores were captured by six possible combinations: (1) increased leaf size and resource use efficiency (leaf area/nutrients) where lower nutrient levels are invested in leaf construction, but a reduction in the number of leaves, for example, forbs in both vegetation types, (2) increased leaf size and resource use efficiency, for example, legumes in short grass, (3) increased leaf size but a reduction in the number of leaves, for example, legumes in the tall grass, (4) increased number of leaves produced and increased resource use efficiency, for example, grasses in the short grass, (5) increased resource use efficiency of leaves only, for example, grasses and sedges in the tall grass, and (6) no response in terms of leaf construction or dominance, for example, sedges in the short grass. Although we found multiple

The natural history of chronic obstructive pulmonary disease

DEFF Research Database (Denmark)

Mannino, DM; Watt, G; Hole, D

2006-01-01

. Exacerbations of COPD are additional important indicators of both quality of life and outcomes in COPD patients. Definitions of exacerbations can vary, ranging from an increase in symptoms to COPD-related hospitalisations and death. COPD exacerbations are more common in patients with lower levels of lung...... function and may lead to more rapid declines in lung function. Better understanding of the natural history of COPD may lead to better definitions of specific COPD phenotypes, better interventions and improved outcomes....

Online Astronomy Resources from the American Museum of Natural History

Science.gov (United States)

Steiner, Robert

2010-02-01

The American Museum of Natural History, one of the world's largest natural history museums, is the locus of a rich array of scientific research, exhibition and educational resources through its Department of Astrophysics, its Rose Center for Earth and Space and its Hall of Meteorites. For the past decade, the Museum's National Center for Science Literacy, Education and Technology has leveraged these assets to create a panoply of web-based resources for students, teachers and the general public. This session will review several of these resources, including the Digital Universe (a three-dimensional mapping of the Universe); The Solar System (an online graduate course for K-12 teachers); multimedia highlighting searches for exoplanets and ultra-high-energy cosmic rays; Journey to the Stars (a DVD version of the current planetarium show); and the astronomy section of Ology (a website for children ages 7 and up). A copy of the Journey to the Stars DVD will be provided to all attendees. )

Impact of life history traits on gene flow: A multispecies systematic review across oceanographic barriers in the Mediterranean Sea

KAUST Repository

Pascual, Marta

2017-05-10

Marine species can demonstrate strong genetic differentiation and population structure despite the hypothesis of open seas and high connectivity. Some suggested drivers causing the genetic breaks are oceanographic barriers and the species\\' biology. We assessed the relevance of seven major oceanographic fronts on species connectivity while considering their dispersal capacity and life strategy.We systematically reviewed the scientific articles reporting population genetic differentiation along the Mediterranean Sea and across the Atlantic-Mediterranean transition. We retained those considering at least one sampling locality at each side of an oceanographic front, and at least two localities with no-front between them to correctly assess the effect of the front. To estimate the impact of life history characteristics affecting connectivity we considered the planktonic larval duration (PLD) and adult life strategy.Oceanographic barriers in the Mediterranean Sea seem to reduce gene flow globally; however, this effect is not homogeneous considering the life history traits of the species. The effect of the oceanographic fronts reduces gene flow in highly mobile species with PLD larger than 2-4 weeks. Benthic sessile species and/or with short PLD (< 2 weeks) have more significant genetic breaks between localities than species with higher motility; however, genetic differentiation occurs independently of the presence of a front.Genetic connectivity is important for populations to recover from anthropogenic or natural impacts. We show that species with low mobility, mostly habitat-formers, have high genetic differentiation but low gene flow reduction mediated by the front, therefore, considering the importance of these species, we emphasize the vulnerability of the Mediterranean ecosystems and the necessity of protection strategies based on the whole ecosystem.

A portrait of a sucker using landscape genetics: how colonization and life history undermine the idealized dendritic metapopulation.

Science.gov (United States)

Salisbury, Sarah J; McCracken, Gregory R; Keefe, Donald; Perry, Robert; Ruzzante, Daniel E

2016-09-01

Dendritic metapopulations have been attributed unique properties by in silico studies, including an elevated genetic diversity relative to a panmictic population of equal total size. These predictions have not been rigorously tested in nature, nor has there been full consideration of the interacting effects among contemporary landscape features, colonization history and life history traits of the target species. We tested for the effects of dendritic structure as well as the relative importance of life history, environmental barriers and historical colonization on the neutral genetic structure of a longnose sucker (Catostomus catostomus) metapopulation in the Kogaluk watershed of northern Labrador, Canada. Samples were collected from eight lakes, genotyped with 17 microsatellites, and aged using opercula. Lakes varied in differentiation, historical and contemporary connectivity, and life history traits. Isolation by distance was detected only by removing two highly genetically differentiated lakes, suggesting a lack of migration-drift equilibrium and the lingering influence of historical factors on genetic structure. Bayesian analyses supported colonization via the Kogaluk's headwaters. The historical concentration of genetic diversity in headwaters inferred by this result was supported by high historical and contemporary effective sizes of the headwater lake, T-Bone. Alternatively, reduced allelic richness in headwaters confirmed the dendritic structure's influence on gene flow, but this did not translate to an elevated metapopulation effective size. A lack of equilibrium and upstream migration may have dampened the effects of dendritic structure. We suggest that interacting historical and contemporary factors prevent the achievement of the idealized traits of a dendritic metapopulation in nature. © 2016 John Wiley & Sons Ltd.

75 FR 57288 - Notice of Inventory Completion: Utah Museum of Natural History, Salt Lake City, UT

Science.gov (United States)

2010-09-20

... Natural History, Salt Lake City, UT AGENCY: National Park Service, Interior. ACTION: Notice. Notice is... possession and control of the Utah Museum of Natural History, Salt Lake City, UT. The human remains and... unworked faunal bone. The associated funerary objects found with the interments indicate that the human...

Natural History of Progression of Chronic Kidney Disease in Stages ...

African Journals Online (AJOL)

Natural History of Progression of Chronic Kidney Disease in Stages 4 and 5. ... Conclusion: Low serum bicarbonate level and high urinary protein excretion at baseline are independent predictors of progression in stage 4 and 5 CKD. Keywords: Chronic kidney disease; End stage renal disease; Glomerular filtration rate; ...

Natural History of Pseudoboine Snakes

Directory of Open Access Journals (Sweden)

Marília P. Gaiarsa

2013-01-01

Full Text Available Even though natural history information is crucial for answering key ecological, evolutionary, and conservation questions, basic studies are still lacking for Neotropical snakes. This study aims at contributing to the knowledge of the Neotropical tribe Pseudoboini, based on literature data, analysis of museum specimens and unpublished data. The tribe is mainly composed of moderate-sized snakes, although small and large-sized snakes also occur in the clade. Mean fecundity ranged from two (Rodriguesophis iglesiasi to 29 eggs (Clelia plumbea and the species are predominantly terrestrial and nocturnal. Most species are diet specialists and lizards are the most commonly consumed prey (found in the diet of 29 species, followed by small mammals (consumed by 20 species and snakes (consumed by 18 species. Although the tribe Pseudoboini appears to be well studied, for 15 species (32% only a small amount of information or none was available. We hope that our study can motivate research on the least known species.

Initiating and continuing participation in citizen science for natural history.

Science.gov (United States)

Everett, Glyn; Geoghegan, Hilary

2016-07-22

Natural history has a long tradition in the UK, dating back to before Charles Darwin. Developing from a principally amateur pursuit, natural history continues to attract both amateur and professional involvement. Within the context of citizen science and public engagement, we examine the motivations behind citizen participation in the national survey activities of the Open Air Laboratories (OPAL) programme, looking at: people's experiences of the surveys as 'project-based leisure'; their motivations for taking part and barriers to continued participation; where they feature on our continuum of engagement; and whether participation in an OPAL survey facilitated their movement between categories along this continuum. The paper focuses on a less-expected but very significant outcome regarding the participation of already-engaged amateur naturalists in citizen science. Our main findings relate to: first, how committed amateur naturalists (already-engaged) have also enjoyed contributing to OPAL and the need to respect and work with their interest to encourage broader and deeper involvement; and second, how new (previously-unengaged) and relatively new participants (casually-engaged) have gained confidence, renewed their interests, refocussed their activities and/or gained validation from participation in OPAL. Overall, we argue that engagement with and enthusiasm for the scientific process is a motivation shared by citizens who, prior to participating in the OPAL surveys, were previously-unengaged, casually-engaged or already-engaged in natural history activities. Citizen science has largely been written about by professional scientists for professional scientists interested in developing a project of their own. This study offers a qualitative example of how citizen science can be meaningful to participants beyond what might appear to be a public engagement data collection exercise.

Using traits to uncover tropical forest function

Energy Technology Data Exchange (ETDEWEB)

McDowell, Nate G. [Pacific Northwest National Laboratory, Richland WA 99352 USA; Xu, Chonggang [Los Alamos National Laboratory, Los Alamos NM 87545 USA

2017-04-11

Plant traits reflect their evolutionary history and influence physiological processes (Reich, 2014). For example, the embolism risk taken by plants, called the embolism safety margin, is a good predictor of stomatal conductance, and hence photosynthesis (Skelton et al., 2015). Trait-science has grown dramatically in the last decade as we have found niversal patterns governing the carbon and nutrient economies of plants (Bloom et al., 1985). Perhaps the greatest value of studying plant functional traits is that they yield understanding of plant functional processes.

78 FR 2434 - Notice of Inventory Completion: Natural History Museum of Utah, Salt Lake City, UT

Science.gov (United States)

2013-01-11

... Inventory Completion: Natural History Museum of Utah, Salt Lake City, UT AGENCY: National Park Service..., 2013. ADDRESSES: Duncan Metcalfe, Natural History Museum of Utah, 301 Wakara Way, Salt Lake City, UT... lot of horse tack, a metal punch, 1 piece of worked wood, gunshot, two mirrors, a harness ring, an awl...

Clarifying the link between childhood abuse history and psychopathic traits in adult criminal offenders

Science.gov (United States)

Dargis, Monika; Newman, Joseph; Koenigs, Michael

2015-01-01

Childhood abuse is a risk factor for the development of externalizing characteristics and disorders, including antisocial personality disorder and psychopathy. However, the precise relationships between particular types of childhood maltreatment and subsequent antisocial and psychopathic traits remain unclear. Using a large sample of incarcerated adult male criminal offenders (n = 183), the current study confirmed that severity of overall childhood maltreatment was linked to severity of both psychopathy and antisocial personality disorder in adulthood. Moreover, this relationship was particularly strong for physical abuse and the antisocial facet of psychopathy. Sexual abuse history was uniquely related to juvenile conduct disorder severity, rather than adult psychopathy or antisocial behaviors. Additionally, there was a significantly stronger relationship between childhood maltreatment and juvenile conduct disorder than between childhood maltreatment and ASPD or psychopathy. These findings bolster and clarify the link between childhood maltreatment and antisocial behavior later in life. PMID:26389621

Predicting the natural mortality of marine fish from life history characteristics

DEFF Research Database (Denmark)

Gislason, Henrik

For fish much of the life history is determined by body size. Body size and asymptotic size significantly influences important life history processes such as growth, maturity, egg production, and natural mortality. Futhermore, for a population to persist, offspring must be able to replace...... their parents on a one-for-one basis in the long run. Otherwise the population would either increase exponentially or become extinct. Combining data on growth and specific fecundity in a size-based fish community model of the North Sea and using the requirement of a one-for-one replacement provides...... the information necessary to estimate the scaling of natural mortality with size and asymptotic size. The estimated scaling is compared with output from multispecies fish stock models, with the empirical scaling of the maximum number of recruits per unit of spawning stock biomass with body size...

78 FR 2430 - Notice of Inventory Completion: Natural History Museum of Utah, Salt Lake City, UT

Science.gov (United States)

2013-01-11

... Inventory Completion: Natural History Museum of Utah, Salt Lake City, UT AGENCY: National Park Service...: Duncan Metcalfe, Natural History Museum of Utah, 301 Wakara Way, Salt Lake City, UT 84108, telephone (801... fragments, 13 pieces of horse tack, 3 saddle fragments, 1 knife sheath, 1 rifle and barrel, 1 lot of bullet...

A population genetic interpretation of GWAS findings for human quantitative traits

Science.gov (United States)

Bullaughey, Kevin; Hudson, Richard R.; Sella, Guy

2018-01-01

Human genome-wide association studies (GWASs) are revealing the genetic architecture of anthropomorphic and biomedical traits, i.e., the frequencies and effect sizes of variants that contribute to heritable variation in a trait. To interpret these findings, we need to understand how genetic architecture is shaped by basic population genetics processes—notably, by mutation, natural selection, and genetic drift. Because many quantitative traits are subject to stabilizing selection and because genetic variation that affects one trait often affects many others, we model the genetic architecture of a focal trait that arises under stabilizing selection in a multidimensional trait space. We solve the model for the phenotypic distribution and allelic dynamics at steady state and derive robust, closed-form solutions for summary statistics of the genetic architecture. Our results provide a simple interpretation for missing heritability and why it varies among traits. They predict that the distribution of variances contributed by loci identified in GWASs is well approximated by a simple functional form that depends on a single parameter: the expected contribution to genetic variance of a strongly selected site affecting the trait. We test this prediction against the results of GWASs for height and body mass index (BMI) and find that it fits the data well, allowing us to make inferences about the degree of pleiotropy and mutational target size for these traits. Our findings help to explain why the GWAS for height explains more of the heritable variance than the similarly sized GWAS for BMI and to predict the increase in explained heritability with study sample size. Considering the demographic history of European populations, in which these GWASs were performed, we further find that most of the associations they identified likely involve mutations that arose shortly before or during the Out-of-Africa bottleneck at sites with selection coefficients around s = 10−3. PMID

Revealing life-history traits by contrasting genetic estimations with predictions of effective population size.

Science.gov (United States)

Greenbaum, Gili; Renan, Sharon; Templeton, Alan R; Bouskila, Amos; Saltz, David; Rubenstein, Daniel I; Bar-David, Shirli

2017-12-22

Effective population size, a central concept in conservation biology, is now routinely estimated from genetic surveys and can also be theoretically predicted from demographic, life-history, and mating-system data. By evaluating the consistency of theoretical predictions with empirically estimated effective size, insights can be gained regarding life-history characteristics and the relative impact of different life-history traits on genetic drift. These insights can be used to design and inform management strategies aimed at increasing effective population size. We demonstrated this approach by addressing the conservation of a reintroduced population of Asiatic wild ass (Equus hemionus). We estimated the variance effective size (N ev ) from genetic data (N ev =24.3) and formulated predictions for the impacts on N ev of demography, polygyny, female variance in lifetime reproductive success (RS), and heritability of female RS. By contrasting the genetic estimation with theoretical predictions, we found that polygyny was the strongest factor affecting genetic drift because only when accounting for polygyny were predictions consistent with the genetically measured N ev . The comparison of effective-size estimation and predictions indicated that 10.6% of the males mated per generation when heritability of female RS was unaccounted for (polygyny responsible for 81% decrease in N ev ) and 19.5% mated when female RS was accounted for (polygyny responsible for 67% decrease in N ev ). Heritability of female RS also affected N ev ; hf2=0.91 (heritability responsible for 41% decrease in N ev ). The low effective size is of concern, and we suggest that management actions focus on factors identified as strongly affecting Nev, namely, increasing the availability of artificial water sources to increase number of dominant males contributing to the gene pool. This approach, evaluating life-history hypotheses in light of their impact on effective population size, and contrasting

The Effect of Project-Based History and Nature of Science Practices on the Change of Nature of Scientific Knowledge

Science.gov (United States)

Çibik, Ayse Sert

2016-01-01

The aim of this study is to compare the change of pre-service science teachers' views about the nature of scientific knowledge through Project-Based History and Nature of Science training and Conventional Method. The sample of the study consists of two groups of 3rd grade undergraduate students attending teacher preparation program of science…

The Biology and Natural History of Aphaenogaster rudis

Directory of Open Access Journals (Sweden)

David Lubertazzi

2012-01-01

Full Text Available Workers from the genus Aphaenogaster are among the most abundant ants in the hardwood forests of eastern North America. The biology of these so-called rudis-group ant species, including details about their sociometry, productivity, natural history, and behavior, are synthesized here using published and newly collected data. The latter was collected, in part, using an artificial field nest, and its construction and use are explained. Ants of the rudis group occur in high densities in forest habitats (0.5–1.3 nests m2, have moderate sized colonies (population means from 266 to 613 workers per nest, and are keystone seed dispersers. Many aspects of their life history and behavior follow an annual cycle that tracks seasonal changes. These include foraging, reproduction, the production of new workers and nest migrations. This synthesis highlights what is known about these ants and reveals gaps in our knowledge that require further study.

The importance of scientific collecting and natural history museums for comparative neuroanatomy.

Science.gov (United States)

Iwaniuk, Andrew N

2011-05-01

The comparative study of vertebrate brains is inherently dependent upon access to a sufficient number of species and specimens to perform meaningful comparisons. Although many studies rely on compiling published information, continued specimen collection, in addition to more extensive use of existing brain collections and natural history museums, are crucial for detailed neuroanatomical comparisons across species. This review highlights the importance of collecting species through a variety of means, details a marsupial brain collection, and stresses the potential of natural history museums as a resource for comparative neuroanatomy. By taking advantage of as many of these resources as possible, researchers can rapidly increase species coverage and generate a better understanding of how the brain evolves. © 2011 New York Academy of Sciences.

EVALUATION OF SUBLETHAL EFFECTS OF Ipomoea cairica LINN. EXTRACT ON LIFE HISTORY TRAITS OF DENGUE VECTORS

Directory of Open Access Journals (Sweden)

Wan Fatma ZUHARAH

2016-01-01

Full Text Available Plant derived insecticides have considerable potential for mosquito control because these products are safer than conventional insecticides. This study aimed to investigate sublethal activities of Ipomoea carica or railway creeper crude acethonilic extract against life history trait of dengue vectors, Aedes albopictus and Aedes aegypti. The late third instar larvae of Ae. albopictus and Ae. aegypti were exposed to a sublethal dose at LC50 and larvae that survived were further cultured. Overall, Ipomea cairica crude extracts affected the whole life history of both Aedes species. The study demonstrated significantly lower egg production (fecundity and eggs hatchability (fertility in Ae. albopictus. The sublethal dose of crude extracts reduced significantly the width of larval head capsule and the wing length of both sexes in both Aedes species. The significance of sublethal effects of I. cairica against Aedes mosquitoes was an additional hallmark to demonstrate further activity of this plant despite its direct toxicity to the larvae. The reduced reproductive capacity as well as morphological and physiological anomalies are some of the effects that make I. cairica a potential candidate to be used as a new plant-based insecticide to control dengue vectors.

From Darwin's Origin of Species toward a theory of natural history.

Science.gov (United States)

Boero, Ferdinando

2015-01-01

Darwin is the father of evolutionary theory because he identified evolutionary patterns and, with Natural Selection, he ascertained the exquisitely ecological ultimate processes that lead to evolution. The proximate processes of evolution he proposed, however, predated the discovery of genetics, the backbone of modern evolutionary theory. The later discovery of the laws of inheritance by Mendel and the rediscovery of Mendel in the early 20th century led to two reforms of Darwinism: Neo-Darwinism and the Modern Synthesis (and subsequent refinements). If Darwin's evolutionary thought required much refinement, his ecological insight is still very modern. In the first edition of The Origin of Species, Darwin did not use either the word "evolution" or the word "ecology". "Ecology" was not coined until after the publication of the Origin. Evolution, for him, was the origin of varieties, then species, which he referred to as well-marked varieties, whereas, instead of using ecology, he used "the economy of nature". The Origin contains a high proportion of currently accepted ecological principles. Darwin labelled himself a naturalist. His discipline (natural history) was a blend of ecology and evolution in which he investigated both the patterns and the processes that determine the organization of life. Reductionist approaches, however, often keep the two disciplines separated from each other, undermining a full understanding of natural phenomena that might be favored by blending ecology and evolution through the development of a modern Theory of Natural History based on Darwin's vision of the study of life.

A Quantitative Genomic Approach for Analysis of Fitness and Stress Related Traits in a Drosophila melanogaster Model Population

DEFF Research Database (Denmark)

Rohde, Palle Duun; Krag, Kristian; Loeschcke, Volker

2016-01-01

, to investigate whether this population harbors genetic variation for a set of stress resistance and life history traits. Using a genomic approach, we found substantial genetic variation for metabolic rate, heat stress resistance, expression of a major heat shock protein, and egg-to-adult viability investigated......The ability of natural populations to withstand environmental stresses relies partly on their adaptive ability. In this study, we used a subset of the Drosophila Genetic Reference Panel, a population of inbred, genome-sequenced lines derived from a natural population of Drosophila melanogaster...... at a benign and a higher stressful temperature. This suggests that these traits will be able to evolve. In addition, we outline an approach to conduct pathway associations based on genomic linear models, which has potential to identify adaptive genes and pathways, and therefore can be a valuable tool...

Assortment and the analysis of natural selection on social traits.

Science.gov (United States)

McDonald, Grant C; Farine, Damien R; Foster, Kevin R; Biernaskie, Jay M

2017-11-01

A central problem in evolutionary biology is to determine whether and how social interactions contribute to natural selection. A key method for phenotypic data is social selection analysis, in which fitness effects from social partners contribute to selection only when there is a correlation between the traits of individuals and their social partners (nonrandom phenotypic assortment). However, there are inconsistencies in the use of social selection that center around the measurement of phenotypic assortment. Here, we use data analysis and simulations to resolve these inconsistencies, showing that: (i) not all measures of assortment are suitable for social selection analysis; and (ii) the interpretation of assortment, and how to detect nonrandom assortment, will depend on the scale at which it is measured. We discuss links to kin selection theory and provide a practical guide for the social selection approach. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

Trans-generational effects of mild heat stress on the life history traits of an aphid parasitoid.

Science.gov (United States)

Ismaeil, Ibrahim; Doury, Géraldine; Desouhant, Emmanuel; Dubois, Françoise; Prevost, Geneviève; Couty, Aude

2013-01-01

Temperature changes are common in nature and insects are particularly exposed and sensitive to such variations which can be potential stresses, ultimately affecting life history traits and overall fitness. Braconids have been widely used to study the effects of temperature on host-parasitoid interactions and the present work focused on the solitary endoparasitoid Aphidius ervi Haliday (Hymenoptera: Braconidae Aphidiidae), an efficient biological control agent commercially used against aphids such as the potato aphid Macrosiphum euphorbiae Thomas (Sternorrhyncha: Aphididae). Contrary to previous studies using heat shocks at extreme temperatures, we evaluated the effects of mild heat stresses by transferring young parasitoid adults from the constant temperature of 20°C to either a warm (25°C) or hot (28°C) temperature, for either 1 h or 48 h. Such treatments are consistent with situations commonly experienced by parasitoids when moved from their rearing conditions to greenhouses or field conditions. The effects were evaluated both on the heat stressed A. ervi adults (G0) (immediate effects) and on their first generation (G1) progeny (trans-generational effects). G0 wasps' mortality was significantly affected by the temperature in interaction with the duration of the stress. Longevity of G0 wasps surviving the heat stress was negatively affected by the temperature and females lived longer than males. Heat stress applied to A. ervi parents also had consequences on their G1 progeny whose developmental time, rates of mummification and percentage of parasitoid completing total development were negatively affected. Surprisingly, the egg load at emergence of the G1 female progeny was increased when their mothers had been submitted to a mild heat stress of 25°C or 28°C. These results clearly demonstrate trans-generational phenotypic plasticity, showing that adaptation to thermal stresses may be achieved via maternal effects. This study also sheds light on the complexity

Trans-generational effects of mild heat stress on the life history traits of an aphid parasitoid.

Directory of Open Access Journals (Sweden)

Ibrahim Ismaeil

Full Text Available Temperature changes are common in nature and insects are particularly exposed and sensitive to such variations which can be potential stresses, ultimately affecting life history traits and overall fitness. Braconids have been widely used to study the effects of temperature on host-parasitoid interactions and the present work focused on the solitary endoparasitoid Aphidius ervi Haliday (Hymenoptera: Braconidae Aphidiidae, an efficient biological control agent commercially used against aphids such as the potato aphid Macrosiphum euphorbiae Thomas (Sternorrhyncha: Aphididae. Contrary to previous studies using heat shocks at extreme temperatures, we evaluated the effects of mild heat stresses by transferring young parasitoid adults from the constant temperature of 20°C to either a warm (25°C or hot (28°C temperature, for either 1 h or 48 h. Such treatments are consistent with situations commonly experienced by parasitoids when moved from their rearing conditions to greenhouses or field conditions. The effects were evaluated both on the heat stressed A. ervi adults (G0 (immediate effects and on their first generation (G1 progeny (trans-generational effects. G0 wasps' mortality was significantly affected by the temperature in interaction with the duration of the stress. Longevity of G0 wasps surviving the heat stress was negatively affected by the temperature and females lived longer than males. Heat stress applied to A. ervi parents also had consequences on their G1 progeny whose developmental time, rates of mummification and percentage of parasitoid completing total development were negatively affected. Surprisingly, the egg load at emergence of the G1 female progeny was increased when their mothers had been submitted to a mild heat stress of 25°C or 28°C. These results clearly demonstrate trans-generational phenotypic plasticity, showing that adaptation to thermal stresses may be achieved via maternal effects. This study also sheds light on

The Impact of Diet Protein and Carbohydrate on Select Life-History Traits of The Black Soldier Fly Hermetia illucens (L.) (Diptera: Stratiomyidae).

Science.gov (United States)

Cammack, Jonathan A; Tomberlin, Jeffery K

2017-05-31

This study examined the impact of diet protein and carbohydrate percentages as well as moisture on the immature development, survivorship, and resulting adult longevity and egg production of the black soldier fly, Hermetia illucens (L.) (Diptera: Stratiomyidae). Moisture impacted development and corresponding life-history traits more than protein:carbohydrate content; larvae were unable to develop on diets at 40% moisture. Larvae fed diets at 70% moisture developed faster, grew larger, and required less food than those reared on diets at 55% moisture. Larvae reared on the balanced diet (21% protein:21% carbohydrate) at 70% moisture developed the fastest on the least amount of food and had the greatest survivorship to the prepupal stage. Adult emergence and longevity were similar across treatments, indicating immature life-history traits were impacted the most. The control (Gainesville house fly) diet was superior to the artificial diets for all parameters tested. These differences could indicate that other constituents (e.g., associated microbes) serve a role in black soldier fly development. These data are valuable for industrialization of this insect as a "green" technology for recycling organic waste, which can be highly variable, to produce protein for use as feed in the livestock, poultry, and aquaculture industries, as well as for bioenergy production.

Natural history of intracranial meningioma after radiotherapy

International Nuclear Information System (INIS)

Monzen, Yoshio

1999-01-01

The author examined the natural history of intracranial meningioma after radiotherapy using CT or MR imaging. Twenty patients with intracranial meningioma received radiotherapy from a high-energy linear accelerator (4-10 MV X rays) from 1980 to 1996. The total doses were 50 Gy to the tumor bed in single doses of 2 Gy in 5 weekly fractions. Meningiomas in 10 of 20 patients were reduced within 1 to 38 months after radiotherapy, the average being 11 months. The tumors were controlled for a median of 60 months after radiotherapy (range 19-126 months). Four other patients have shown no change in tumor size after radiotherapy. The tumors were controlled for a median of 70 months after radiotherapy (range 37-127 months). The other six patients have shown tumor growth within 3 to 25 months after radiotherapy, after which the tumors stopped growing for a median of 71 months (range 2-181 months). Neither tumor size nor histological type was related to response. The growth of tumors was controlled by radiotherapy for a median duration of 43 months in the meningothelial type, 52 months in the fibroblastic type, and 61 months in the transitional type. The median duration for all benign tumors was 52 months. A moderate correlation was noted between tumor response and functional outcome after radiotherapy in 9 patients with neurological deficits. The natural histories of intracranial meningiomas after radiotherapy were grouped into three categories. Some tumors showed no change in size over a long period. This was a characteristic response after radiotherapy that differed from that of other brain tumors. The results of this study provide important information for the follow-up of intracranial meningiomas after radiotherapy. (author)

Naturalization of central European plants in North America: species traits, habitats, propagule pressure, residence time

Czech Academy of Sciences Publication Activity Database

Pyšek, Petr; Manceur, A. M.; Alba, Christina; McGregor, Kirsty; Pergl, Jan; Štajerová, Kateřina; Chytrý, M.; Danihelka, Jiří; Kartesz, J.; Klimešová, Jitka; Lučanová, Magdalena; Moravcová, Lenka; Nishino, M.; Sádlo, Jiří; Suda, Jan; Tichý, L.; Kühn, I.

2015-01-01

Roč. 96, č. 3 (2015), s. 762-774 ISSN 0012-9658 R&D Projects: GA ČR GB14-36079G; GA ČR(CZ) GA14-15414S; GA ČR(CZ) GAP504/11/1028; GA ČR(CZ) GAP505/11/1112 Grant - others:AV ČR(CZ) AP1002 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:67985939 Keywords : invasions * naturalization * species traits Subject RIV: EH - Ecology, Behaviour Impact factor: 4.733, year: 2015

Natural history of idiopathic abducens nerve paresis in a young adult.

Science.gov (United States)

Hussaindeen, Jameel Rizwana; Mani, Revathy; Rakshit, Archayeeta; Ramasubramanian, Srikanth; Vittal Praveen, Smitha

2016-01-01

The natural history of idiopathic abducens nerve paresis and the role of conservative management such as vision training during the recovery process is not well documented in the literature to the best of our knowledge. This case report presents the natural recovery process of idiopathic abducens nerve paresis in a young adult and the role of vision therapy in the recovery process. Copyright © 2016 Spanish General Council of Optometry. Published by Elsevier España, S.L.U. All rights reserved.

The influence of inherited plumage colour morph on morphometric traits and breeding investment in zebra finches (Taeniopygia guttata.

Directory of Open Access Journals (Sweden)

E Tobias Krause

Full Text Available Melanin-based plumage polymorphism occurs in many wild bird populations and has been linked to fitness variation in several species. These fitness differences often arise as a consequence of variation in traits such as behaviour, immune responsiveness, body size and reproductive investment. However, few studies have controlled for genetic differences between colour morphs that could potentially generate artefactual associations between plumage colouration and trait variation. Here, we used zebra finches (Taeniopygia guttata as a model system in order to evaluate whether life-history traits such as adult body condition and reproductive investment could be influenced by plumage morph. To maximise any potential differences, we selected wild-type and white plumage morphs, which differ maximally in their extent of melanisation, while using a controlled three-generation breeding design to homogenise the genetic background. We found that F2 adults with white plumage colouration were on average lighter and had poorer body condition than wild-type F2 birds. However, they appeared to compensate for this by reproducing earlier and producing heavier eggs relative to their own body mass. Our study thus reveals differences in morphological and life history traits that could be relevant to fitness variation, although further studies will be required to evaluate fitness effects under natural conditions as well as to characterise any potential fitness costs of compensatory strategies in white zebra finches.

Fossil Platygastroidea in the National Museum of Natural History, Smithsonian Institution

Science.gov (United States)

Platygastroid wasps preserved in Dominican amber and oil shale from the Kishenehn formation (Montana, USA) in the National Museum of Natural History are catalogued. Compression fossils in Kishenehn oil shale yield a specimen of Fidiobia, a specimen of Telenominae, and a specimen with a Scelio-type o...

Long-term studies of the natural history of asthma in childhood

DEFF Research Database (Denmark)

Bisgaard, Hans; Bønnelykke, Klaus

2010-01-01

secondary prevention through the use of inhaled corticosteroids can effectively halt the long-term disease progression in childhood. In conclusion, the natural history of asthma and the associated airway changes is still poorly understood, and we have not managed to translate findings from long-term studies...

Breeding for cuticle-associated traits in crop species: traits, targets, and strategies.

Science.gov (United States)

Petit, Johann; Bres, Cécile; Mauxion, Jean-Philippe; Bakan, Bénédicte; Rothan, Christophe

2017-11-09

Improving crop productivity and quality while promoting sustainable agriculture have become major goals in plant breeding. The cuticle is a natural film covering the aerial organs of plants and consists of lipid polyesters covered and embedded with wax. The cuticle protects plants against water loss and pathogens and affects traits with strong impacts on crop quality such as, for horticultural crops, fruit brightness, cracking, russeting, netting, and shelf life. Here we provide an overview of the most important cuticle-associated traits that can be targeted for crop improvement. To date, most studies on cuticle-associated traits aimed at crop breeding have been done on fleshy fruits. Less information is available for staple crops such as rice, wheat or maize. Here we present new insights into cuticle formation and properties resulting from the study of genetic resources available for the various crop species. Our review also covers the current strategies and tools aimed at exploiting available natural and artificially induced genetic diversity and the technologies used to transfer the beneficial alleles affecting cuticle-associated traits to commercial varieties. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Snake and bird predation drive the repeated convergent evolution of correlated life history traits and phenotype in the Izu Island Scincid lizard (Plestiodon latiscutatus.

Directory of Open Access Journals (Sweden)

Matthew C Brandley

Full Text Available Predation may create strong natural selection pressure on the phenotype and life history characteristics of prey species. The Izu scincid lizards (Plestiodon latiscutatus that inhabit the four Japanese Izu Islands with only bird predators are drab brown, mature later, lay small clutches of large eggs, and hatch large neonates. In contrast, skinks on seven islands with both snake and bird predators are conspicuously colored, mature early, lay large clutches of small eggs, and hatch small neonates. We test the hypothesis that these suites of traits have evolved independently on each island via natural selection pressures from one of two predator regimes--birds-only and birds + snakes. Using two mtDNA genes and a nuclear locus, we infer a time-calibrated phylogeny of P. latiscutatus that reveals a basal split between Mikura and all islands south, and Miyake, all islands north, and the Izu Peninsula. Populations inhabiting Miyake, Niijima, Shikine, and Toshima are not monophyletic, suggesting either multiple colonizations or an artifact of incomplete lineage sorting (ILS. We therefore developed novel phylogenetic comparative analyses that assume either a multiple colonization or more restrictive single colonization ILS scenario and found 1 statistically significant support for the of different suites of phenotypic and life history characteristics with the presence of bird-only or bird + snake predator assemblages, and 2 strong phylogenetic support for at least two independent derivations of either the "bird-only" or "snakes + birds" phenotypes regardless of colonization scenario. Finally, our time-calibrated phylogeographic analysis supports the conclusion that the ancestor to modern Izu Island P. latiscutatus dispersed from the mainland to the Izu proto-islands between 3-7.6 million years ago (Ma. These lineages remained present in the area during successive formation of the islands, with one lineage re-colonizing the mainland 0.24-0.7 Ma.

The natural history of surgically treated but radiotherapy-naïve nonfunctioning pituitary adenomas.

LENUS (Irish Health Repository)

O'Sullivan, Eoin P

2009-11-01

Transsphenoidal surgery is indicated for patients with nonfunctioning pituitary adenomas (NFPAs) causing compressive symptoms. Previous studies attempting to define the rate of recurrence\\/regrowth of surgically treated but radiation-naïve NFPAs were somewhat limited by selection bias and\\/or small numbers and\\/or lack of consistency of findings between studies. A better understanding of the natural history of this condition could allow stratification of recurrence risk and inform future management. We aimed to define the natural history of a large, mainly unselected cohort with surgically treated, radiotherapy (RT)-naïve NFPAs and to try to identify predictors of recurrence\\/regrowth.

Reemergence of the Natural History of Otolaryngologic Infections: Lessons Learned from 2 American Presidents.

Science.gov (United States)

Naples, James; Schwartz, Marissa; Eisen, Marc

2017-09-01

Presidents George Washington and Theodore Roosevelt suffered complications of epiglottitis and otomastoiditis, respectively. The introduction of antibiotics and vaccinations against Haemophilus influenzae and Streptococcus pneumoniae has significantly reduced the incidence of these otolaryngologic infections, such that the natural history of the disease is rarely encountered. However, antibiotic resistance and pathogenic evolution has raised concern about increased virulence of these common organisms. A retrospective evaluation of the complications suffered by Washington and Roosevelt provides valuable insight to the natural history of common otolaryngologic infections that may reemerge as a result of organism evolution in response to antibiotics and vaccines.

Citizen science networks in natural history and the collective validation of biodiversity data.

Science.gov (United States)

Turnhout, Esther; Lawrence, Anna; Turnhout, Sander

2016-06-01

Biodiversity data are in increasing demand to inform policy and management. A substantial portion of these data is generated in citizen science networks. To ensure the quality of biodiversity data, standards and criteria for validation have been put in place. We used interviews and document analysis from the United Kingdom and The Netherlands to examine how data validation serves as a point of connection between the diverse people and practices in natural history citizen science networks. We found that rather than a unidirectional imposition of standards, validation was performed collectively. Specifically, it was enacted in ongoing circulations of biodiversity records between recorders and validators as they jointly negotiated the biodiversity that was observed and the validity of the records. These collective validation practices contributed to the citizen science character or natural history networks and tied these networks together. However, when biodiversity records were included in biodiversity-information initiatives on different policy levels and scales, the circulation of records diminished. These initiatives took on a more extractive mode of data use. Validation ceased to be collective with important consequences for the natural history networks involved and citizen science more generally. © 2016 The Authors. Conservation Biology published by Wiley Periodicals, Inc. on behalf of Society for Conservation Biology.

Assessing the quality of life history information in publicly available databases.

Science.gov (United States)

Thorson, James T; Cope, Jason M; Patrick, Wesley S

2014-01-01

Single-species life history parameters are central to ecological research and management, including the fields of macro-ecology, fisheries science, and ecosystem modeling. However, there has been little independent evaluation of the precision and accuracy of the life history values in global and publicly available databases. We therefore develop a novel method based on a Bayesian errors-in-variables model that compares database entries with estimates from local experts, and we illustrate this process by assessing the accuracy and precision of entries in FishBase, one of the largest and oldest life history databases. This model distinguishes biases among seven life history parameters, two types of information available in FishBase (i.e., published values and those estimated from other parameters), and two taxa (i.e., bony and cartilaginous fishes) relative to values from regional experts in the United States, while accounting for additional variance caused by sex- and region-specific life history traits. For published values in FishBase, the model identifies a small positive bias in natural mortality and negative bias in maximum age, perhaps caused by unacknowledged mortality caused by fishing. For life history values calculated by FishBase, the model identified large and inconsistent biases. The model also demonstrates greatest precision for body size parameters, decreased precision for values derived from geographically distant populations, and greatest between-sex differences in age at maturity. We recommend that our bias and precision estimates be used in future errors-in-variables models as a prior on measurement errors. This approach is broadly applicable to global databases of life history traits and, if used, will encourage further development and improvements in these databases.

Natural history of diminutive colorectal polyps: long-term prospective observation by colonoscopy.

Science.gov (United States)

Mizuno, Ken-Ichi; Suzuki, Yutaka; Takeuchi, Manabu; Kobayashi, Masaaki; Aoyagi, Yutaka

2014-04-01

Endoscopic removal of colorectal adenomatous polyps effectively prevents cancer. However, the treatment strategy for diminutive polyps (diameter ≤ 5 mm) remains controversial. Understanding the natural history of diminutive polyps is a prerequisite to their effective management. We prospectively examined the natural history of diminutive polyps by long-term surveillance colonoscopy. A total of 207 polyps detected in 112 patients from December 1991 through March 2002 were studied. To avoid potential effects on size and morphological characteristics, all polyps were selected randomly and were followed without biopsy. Polyp size was estimated by comparing the lesion with the diameter of a biopsy forceps. Mean follow up was 7.8 years (SD, 4.8; range, 1.0-18.6; median, 7.5; interquartile range 3.4-11.2). Twenty-four polyps were resected endoscopically, and the histopathological diagnosis was mucosal high-grade neoplasia (Category 4) for one polyp, and mucosal low-grade neoplasia (Category 3) for 23 polyps. Mean linear size of the polyps was 3.2 mm (SD, 1.0; range, 1.3-5.0) at initial colonoscopy and 3.8 mm (SD 1.6; range 1.3-10.0) at final colonoscopy (Ppit pattern was associated with a lower growth rate than a type IIIL1 pattern. We clarified the natural history of diminutive polyps by long-term follow-up colonoscopy. The benign course of diminutive polyps should be considered in the design of treatment strategies. © 2014 The Authors. Digestive Endoscopy © 2014 Japan Gastroenterological Endoscopy Society.

A Quantitative Genomic Approach for Analysis of Fitness and Stress Related Traits in a Drosophila melanogaster Model Population

Directory of Open Access Journals (Sweden)

Palle Duun Rohde

2016-01-01

Full Text Available The ability of natural populations to withstand environmental stresses relies partly on their adaptive ability. In this study, we used a subset of the Drosophila Genetic Reference Panel, a population of inbred, genome-sequenced lines derived from a natural population of Drosophila melanogaster, to investigate whether this population harbors genetic variation for a set of stress resistance and life history traits. Using a genomic approach, we found substantial genetic variation for metabolic rate, heat stress resistance, expression of a major heat shock protein, and egg-to-adult viability investigated at a benign and a higher stressful temperature. This suggests that these traits will be able to evolve. In addition, we outline an approach to conduct pathway associations based on genomic linear models, which has potential to identify adaptive genes and pathways, and therefore can be a valuable tool in conservation genomics.

[Impact of antiviral therapy on the natural history of hepatitis C virus].

Science.gov (United States)

Fernández Rodriguez, Conrado M; Gutierrez Garcia, Maria Luisa

2014-12-01

Chronic hepatitis C virus infection affects around 150 million persons, and 350,000 persons worldwide die of this disease each year. Although the data on its natural history are incomplete, after the acute infection, most patients develop chronic forms of hepatitis C with variable stages of fibrosis. In these patients, continual inflammatory activity can cause significant fibrosis, cirrhosis, decompensation of the liver disease, or hepatocarcinoma. In the next few years, it is expected that hepatitis C virus infection and its complications will significantly increase, as will the incidence of hepatocarcinoma in Spain. This review presents the data on the natural history of hepatitis C virus infection and discusses the potential impact of antiviral therapy on the distinct stages of the disease. Copyright © 2014 Elsevier España, S.L.U. and AEEH y AEG. All rights reserved.

Trans-generational study of DNA alterations and their consequences on life history traits and energy budget of Daphnia magna exposed to depleted uranium

International Nuclear Information System (INIS)

Plaire, Delphine

2013-01-01

Understanding how toxicants affect species at various levels of biological organization is a major research goal in both ecotoxicology and radioecology. As part of IRSN program ENVIRHOM, which aims to assess environmental risks related to the presence of radionuclides in the environment, this PhD work explored how depleted uranium alters DNA and affects life history traits (survival, growth and reproduction) of an aquatic invertebrate, Daphnia magna. To answer to this problematic, an experimental approach and a modeling approach are conducted. An experimental study is performed to evaluate DNA accumulation and transmission during an uranium exposure (0; 2; 9.9; 22.2 and 50 μg.L -1 ) over two successive generations (F0 and F1). Different exposures scenarios (continuous, post-hatching and embryo exposure) are achieved to test the specific sensitivity of several life stages to uranium. Genotoxic effects are estimated using random amplified DNA technique combined with PCR (PCR-RAPD). In continuous and post-hatching exposure scenarios, results highlighted an accumulation and a transmission of DNA damage across generations with an increase in effect severity. DNA alterations are reported at hatching of the F1 generation at a concentration as low as 2 μg.L -1 . Effects on growth and reproduction are stronger when the embryo stage is exposed and remain visible at 9.9 μg.L -1 despite a return in a clean medium at hatching. Results suggest that DNA damage could be used as early indicators of future effects on life history traits. A mechanistic analysis of experimental results is conducted using a DEBtox model (dynamic energy budget applied to toxicology) to better understand the causes of the increase in effect severity across generations. A model with two stress factors (one correlated to external concentration and another correlated to a damage level) is developed. Results of fits suggest the involvement of one second mode of action to explain immediate effects of

The transition to modernity and chronic disease: mismatch and natural selection.

Science.gov (United States)

Corbett, Stephen; Courtiol, Alexandre; Lummaa, Virpi; Moorad, Jacob; Stearns, Stephen

2018-05-09

The Industrial Revolution and the accompanying nutritional, epidemiological and demographic transitions have profoundly changed human ecology and biology, leading to major shifts in life history traits, which include age and size at maturity, age-specific fertility and lifespan. Mismatch between past adaptations and the current environment means that gene variants linked to higher fitness in the past may now, through antagonistic pleiotropic effects, predispose post-transition populations to non-communicable diseases, such as Alzheimer disease, cancer and coronary artery disease. Increasing evidence suggests that the transition to modernity has also altered the direction and intensity of natural selection acting on many traits, with important implications for public and global health.

Natural history of breast cancers detected in the Swedish mammography screening programme: a cohort study

DEFF Research Database (Denmark)

Zahl, Per-Henrik; Gøtzsche, Peter C; Mæhlen, Jan

2011-01-01

The natural history of screen-detected breast cancers is not well understood. A previous analysis of the incidence change during the introduction of the Norwegian screening programme in the late 1990s suggested that the natural history of many screen-detected invasive breast cancers is to regress...... spontaneously but the study was possibly confounded by use of hormone replacement therapy in the population. We did a similar analysis of data collected during an earlier period when few women were exposed to hormone replacement therapy....

Teaching Science Rhetorically: An Interdisciplinary Approach to Natural History, 1948-1985.

Science.gov (United States)

DePaolo, Charles

1987-01-01

Considers the different analogies used by James Rettie, Teilhard de Chardin, Robert Ardrey, Jacob Bronowski, Richard Leakey, Steven Weinberg, Heinz Pagels, and Carl Sagan to make concepts related to time and natural history accessible to the layperson. Suggests that these analogies be used at the undergraduate level in both humanities and science…

Natural variation in life history and aging phenotypes is associated with mitochondrial DNA deletion frequency in Caenorhabditis briggsae

Directory of Open Access Journals (Sweden)

Smith Samson W

2011-01-01

Full Text Available Abstract Background Mutations that impair mitochondrial functioning are associated with a variety of metabolic and age-related disorders. A barrier to rigorous tests of the role of mitochondrial dysfunction in aging processes has been the lack of model systems with relevant, naturally occurring mitochondrial genetic variation. Toward the goal of developing such a model system, we studied natural variation in life history, metabolic, and aging phenotypes as it relates to levels of a naturally-occurring heteroplasmic mitochondrial ND5 deletion recently discovered to segregate among wild populations of the soil nematode, Caenorhabditis briggsae. The normal product of ND5 is a central component of the mitochondrial electron transport chain and integral to cellular energy metabolism. Results We quantified significant variation among C. briggsae isolates for all phenotypes measured, only some of which was statistically associated with isolate-specific ND5 deletion frequency. We found that fecundity-related traits and pharyngeal pumping rate were strongly inversely related to ND5 deletion level and that C. briggsae isolates with high ND5 deletion levels experienced a tradeoff between early fecundity and lifespan. Conversely, oxidative stress resistance was only weakly associated with ND5 deletion level while ATP content was unrelated to deletion level. Finally, mean levels of reactive oxygen species measured in vivo showed a significant non-linear relationship with ND5 deletion level, a pattern that may be driven by among-isolate variation in antioxidant or other compensatory mechanisms. Conclusions Our findings suggest that the ND5 deletion may adversely affect fitness and mitochondrial functioning while promoting aging in natural populations, and help to further establish this species as a useful model for explicit tests of hypotheses in aging biology and mitochondrial genetics.

Power and Autistic Traits

Science.gov (United States)

Overskeid, Geir

2016-01-01

Autistic traits can help people gain and sustain power, and has probably done so throughout history, says the present paper. A number of testable claims follow from this assumption. First, the powerful should have more autistic traits than others – which they do appear to have. Among other things, powerful people, and those with many autistic traits, tend to prefer solitary activities and are often aloof. Moreover, they are often rigid and socially insensitive, low on empathy and with low scores on the trait of agreeableness – and as a rule they do not have many friends. Both groups are also more self-centered than others, more honest, less submissive, more sensitive to slights, and with a stronger tendency to engage in abstract thinking. They tend to behave in bossy or dominant ways, and their moral judgment is more based on rules than on feelings. In addition to experimental evidence, I cite biographies showing that a surprising number of presidents, prime ministers and other powerful people seem to have had traits like those in question – and interestingly, in animals, leaders are often rigid and insensitive to group members’ needs and feelings, mostly acting the way they are themselves inclined to, not responding much to others. Problem solving is important in leadership, and people with many autistic traits appear often to be better thinkers than typical subjects with similar IQs. However, these and other congruities could be coincidences. Hence the question of whether traits the two groups have in common also have a common cause constitutes a strong test of the paper’s thesis – and a common cause does appear to exist, in the form of testosterone’s effects on the central nervous system. Finally, there is evidence that, other things equal, powerful men have more reproductive success than others. If men wielding power do indeed have more autistic traits than those less powerful, this will lead to, other things equal, such traits becoming more

Power and Autistic Traits

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Geir Overskeid

2016-08-01

Full Text Available Autistic traits can help people gain and sustain power, and has probably done so throughout history, says the present paper. A number of testable claims follow from this assumption. First, the powerful should have more autistic traits than others – which they do appear to have. Among other things, powerful people, and those with many autistic traits, tend to prefer solitary activities and are often aloof. Moreover, they are often rigid and socially insensitive, low on empathy and with low scores on the trait of agreeableness -- and as a rule they do not have many friends. Both groups are also more self-centered than others, more honest, less submissive, more sensitive to slights, and with a stronger tendency to engage in abstract thinking. They tend to behave in bossy or dominant ways, and their moral judgment is more based on rules than on feelings. In addition to experimental evidence, I cite biographies showing that a surprising number of presidents, prime ministers and other powerful people seem to have had traits like those in question – and interestingly, in animals, leaders are often rigid and insensitive to group members’ needs and feelings, mostly acting the way they are themselves inclined to, not responding much to others. Problem solving is important in leadership, and people with many autistic traits appear often to be better thinkers than typical subjects with similar IQs. However, these and other congruities could be coincidences. Hence the question of whether traits the two groups have in common also have a common cause constitutes a strong test of the paper’s thesis – and a common cause does appear to exist, in the form of testosterone’s effects on the central nervous system. Finally, there is evidence that, other things equal, powerful men have more reproductive success than others. If men wielding power do indeed have more autistic traits than those less powerful, this will lead to, other things equal, such traits

Has long-term metal exposure induced changes in life history traits and genetic diversity of the enchytraeid worm Cognettia sphagnetorum (Vejd.)?

International Nuclear Information System (INIS)

Haimi, Jari; Knott, Karelyn Emily; Selonen, Salla; Laurikainen, Marjo

2006-01-01

We studied whether long-term metal exposure has affected life history traits, population growth patterns and genetic diversity of the asexual enchytraeid worm Cognettia sphagnetorum (Vejd.). Enchytraeids from metal contaminated and uncontaminated forest soil were compared by growing them individually in the laboratory and by following their population development in patchily Cu contaminated microcosms. Genetic differences between the two native populations were studied using allozyme electrophoresis. Individuals from the contaminated site had slower growth rate and they produced fewer fragments of larger size when compared to individuals from the uncontaminated site. In patchily Cu contaminated microcosms, C. sphagnetorum from the contaminated site had a slower population growth rate. Most alleles were shared by the two native populations, but there was greater diversity and more unique genotypes in the population living in the uncontaminated site. Overall, long-term exposure to metals has induced only slight changes in life history properties and clonal diversity of C. sphagnetorum. - Long-term exposure to metals caused only small changes in life histories of two populations of Cognettia sphagnetorum

Functional Linkages for the Pace of Life, Life-history, and Environment in Birds

OpenAIRE

Williams, Joseph B.; Miller, Richard A.; Harper, James M.; Wiersma, Popko

2010-01-01

For vertebrates, body mass underlies much of the variation in metabolism, but among animals of the same body mass, metabolism varies six-fold. Understanding how natural selection can influence variation in metabolism remains a central focus of Physiological Ecologists. Life-history theory postulates that many physiological traits, such as metabolism, may be understood in terms of key maturational and reproductive characteristics over an organism’s life-span. Although it is widely acknowledged...

Ancestrality and evolution of trait syndromes in finches (Fringillidae).

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Ponge, Jean-François; Zuccon, Dario; Elias, Marianne; Pavoine, Sandrine; Henry, Pierre-Yves; Théry, Marc; Guilbert, Éric

2017-12-01

Species traits have been hypothesized by one of us (Ponge, 2013) to evolve in a correlated manner as species colonize stable, undisturbed habitats, shifting from "ancestral" to "derived" strategies. We predicted that generalism, r-selection, sexual monomorphism, and migration/gregariousness are the ancestral states (collectively called strategy A) and evolved correlatively toward specialism, K-selection, sexual dimorphism, and residence/territoriality as habitat stabilized (collectively called B strategy). We analyzed the correlated evolution of four syndromes, summarizing the covariation between 53 traits, respectively, involved in ecological specialization, r-K gradient, sexual selection, and dispersal/social behaviors in 81 species representative of Fringillidae, a bird family with available natural history information and that shows variability for all these traits. The ancestrality of strategy A was supported for three of the four syndromes, the ancestrality of generalism having a weaker support, except for the core group Carduelinae (69 species). It appeared that two different B-strategies evolved from the ancestral state A, both associated with highly predictable environments: one in poorly seasonal environments, called B1, with species living permanently in lowland tropics, with "slow pace of life" and weak sexual dimorphism, and one in highly seasonal environments, called B2, with species breeding out-of-the-tropics, migratory, with a "fast pace of life" and high sexual dimorphism.

Temperature effects on gametophyte life-history traits and geographic distribution of two cryptic kelp species.

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L Valeria Oppliger

Full Text Available A major determinant of the geographic distribution of a species is expected to be its physiological response to changing abiotic variables over its range. The range of a species often corresponds to the geographic extent of temperature regimes the organism can physiologically tolerate. Many species have very distinct life history stages that may exhibit different responses to environmental factors. In this study we emphasized the critical role of the haploid microscopic stage (gametophyte of the life cycle to explain the difference of edge distribution of two related kelp species. Lessonia nigrescens was recently identified as two cryptic species occurring in parapatry along the Chilean coast: one located north and the other south of a biogeographic boundary at latitude 29-30°S. Six life history traits from microscopic stages were identified and estimated under five treatments of temperature in eight locations distributed along the Chilean coast in order to (1 estimate the role of temperature in the present distribution of the two cryptic L. nigrescens species, (2 compare marginal populations to central populations of the two cryptic species. In addition, we created a periodic matrix model to estimate the population growth rate (λ at the five temperature treatments. Differential tolerance to temperature was demonstrated between the two species, with the gametophytes of the Northern species being more tolerant to higher temperatures than gametophytes from the south. Second, the two species exhibited different life history strategies with a shorter haploid phase in the Northern species contrasted with considerable vegetative growth in the Southern species haploid stage. These results provide strong ecological evidence for the differentiation process of the two cryptic species and show local adaptation of the life cycle at the range limits of the distribution. Ecological and evolutionary implications of these findings are discussed.

Early life history and habitat ecology of estuarine fishes: responses to natural and human induced change

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Kenneth Able

2015-12-01

Full Text Available Our understanding of the early life history of fishes and their habitats has proceeded from basic natural history to ecology, but we often need to return to natural history to address deficiencies in conceptual and quantitative models of ecosystems. This understanding is further limited by the complex life history of fishes and the lack of appreciation of shifting baselines in estuaries. These inadequacies are especially evident when we try to address the effects of human influences, e.g. fishing, urbanization, and climate change. Often our baselines are inadequate or inaccurate. Our work has detected these along the coasts of the U.S. in extensive time series of larval fish ingress into estuaries, studies of the effects of urbanization, and responses to catastrophes such as the BP oil spill. Long-term monitoring, especially, continues to provide critical insights

Natural history and surgical results in patients with unruptured intracranial aneurysms

International Nuclear Information System (INIS)

Okiyama, Koichi; Nagano, Osamu; Machida, Toshio; Serizawa, Toru; Ono, Junichi; Higuchi, Yoshinori

2008-01-01

The management of patients with unruptured intracranial aneurysms (UIAs) is controversial. We aimed to assess the natural history of UIAs and evaluate the surgical results. We analyzed 154 patients (181 saccular UIAs) with no history of subarachnoid hemorrhage (SAH) from a different aneurysm. Aneurysms were detected by magnetic resonance angiography (MRA) or by 3-dimensional CT angiography. Although the most frequent reason for the diagnosis was routine brain examinations of healthy patients or a vague symptom such as headache or dizziness, 15 patients were symptomatic. The natural history in patients who did not have surgery (follow-up group: 76 cases, 95 aneurysms) was assessed, and the surgical outcome of UIAs (surgical group: 78 cases, 86 aneurysms) was evaluated. Among 76 patients in the follow-up group, 7 had SAH. The mean latency period to aneurysm rupture was 3.2 months. The aneurysms with subsequent bleeding ranged from 5 to 25 mm (19.3 mm on average), whereas those without ranged from 1 to 28 mm (4.5 mm on average). The rupture rates of UIAs in anterior and posterior circulation were 6.2% and 14.3%, respectively. All ruptured cases were females. Mortality and morbidity associated with UIAs in the follow-up group were 3.9% and 3.9%, respectively. In the surgical group, no mortality was noted. Permanent morbidity associated with prospective repair of UIAs was 5.1%, although the morbidity of the patients with preoperative Rankin scores of 0 or 1 was 1.3%. Transient morbidity was observed in 6 patients (7.7%) with the size of the aneurysm 19.8 mm on average. The natural history and surgical results in patients with UIAs are modified by several factors including aneurysm size and location, the patient's age and gender, the medical status and the patient's preoperative Rankin score. The present results indicated that these factors should be considered in deciding whether to treat UIAs, and that careful assessment of the surgical benefits might be essential

Food and fitness: associations between crop yields and life-history traits in a longitudinally monitored pre-industrial human population.

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Hayward, Adam D; Holopainen, Jari; Pettay, Jenni E; Lummaa, Virpi

2012-10-22

Severe food shortage is associated with increased mortality and reduced reproductive success in contemporary and historical human populations. Studies of wild animal populations have shown that subtle variation in environmental conditions can influence patterns of mortality, fecundity and natural selection, but the fitness implications of such subtle variation on human populations are unclear. Here, we use longitudinal data on local grain production, births, marriages and mortality so as to assess the impact of crop yield variation on individual age-specific mortality and fecundity in two pre-industrial Finnish populations. Although crop yields and fitness traits showed profound year-to-year variation across the 70-year study period, associations between crop yields and mortality or fecundity were generally weak. However, post-reproductive individuals of both sexes, and individuals of lower socio-economic status experienced higher mortality when crop yields were low. This is the first longitudinal, individual-based study of the associations between environmental variation and fitness traits in pre-industrial humans, which emphasizes the importance of a portfolio of mechanisms for coping with low food availability in such populations. The results are consistent with evolutionary ecological predictions that natural selection for resilience to food shortage is likely to weaken with age and be most severe on those with the fewest resources.

Classical Natural History: the importance of volunteers in collection management and research

NARCIS (Netherlands)

Reumer, J.W.F.; Post, K.

2010-01-01

As a result of increasing budget constraints and decreasing interest in classical natural history, the work effort of volunteer researchers and the need for private funding are of growing importance. A brief historical background is provided, showing the decreasing interest in the subject shown by

Natural Reforestation Reclaims a Watershed: A Case History from West Virginia

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W.P. Lima; J.H. Patric; N. Holowaychuk

1978-01-01

Thirteen years of hydrologic data from two contiguous small watersheds in West Virginia were analyzed to determine the effects on streamflow of natural reforestation on abandoned farmlands. During the study period (1958-1970), streamflow on the watersheds was unchanged. The history of land use on the study area helps explain the apparent lack of hydrologic effects of...

History of Science as an Instructional Context: Student Learning in Genetics and Nature of Science

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Kim, Sun Young; Irving, Karen E.

2010-01-01

This study (1) explores the effectiveness of the contextualized history of science on student learning of nature of science (NOS) and genetics content knowledge (GCK), especially interrelationships among various genetics concepts, in high school biology classrooms; (2) provides an exemplar for teachers on how to utilize history of science in…

Multiple growth-correlated life history traits estimated simultaneously in indivuals

NARCIS (Netherlands)

Mollet, F.M.; Ernande, B.; Brunel, T.P.A.; Rijnsdorp, A.D.

2010-01-01

We present a new methodology to estimate rates of energy acquisition, maintenance, reproductive investment and the onset of maturation (four-trait estimation) by fitting an energy allocation model to individual growth trajectories. The accuracy and precision of the method is evaluated on simulated

The natural history and management of brachial plexus birth palsy

OpenAIRE

Buterbaugh, Kristin L.; Shah, Apurva S.

2016-01-01

Brachial plexus birth palsy (BPBP) is an upper extremity paralysis that occurs due to traction injury of the brachial plexus during childbirth. Approximately 20 % of children with brachial plexus birth palsy will have residual neurologic deficits. These permanent and significant impacts on upper limb function continue to spur interest in optimizing the management of a problem with a highly variable natural history. BPBP is generally diagnosed on clinical examination and does not typically req...

Taking Spectacle Seriously: Wildlife Film and the Legacy of Natural History Display.

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Louson, Eleanor

2018-03-01

Argument I argue through an analysis of spectacle that the relationship between wildlife documentary films' entertainment and educational mandates is complex and co-constitutive. Accuracy-based criticism of wildlife films reveals assumptions of a deficit model of science communication and positions spectacle as an external commercial pressure influencing the genre. Using the Planet Earth (2006) series as a case study, I describe spectacle's prominence within the recent blue-chip renaissance in wildlife film, resulting from technological innovations and twenty-first-century consumer and broadcast market contexts. I connect spectacle in contemporary wildlife films to its relevant precursors within natural history, situating spectacle as a central feature of natural history display designed to inspire awe and wonder in audiences. I show that contemporary documentary spectacle is best understood as an opportunity for affective knowing rather than a constraint on accuracy; as a result, spectacle contributes to the virtuous inter-reinforcement of entertainment and education at work in blue-chip wildlife films.

Personality Traits of Substance Users in Bangladesh

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Jotirmoy Roy

2011-02-01

Full Text Available Background: Drug taking behavior and drug dependence is a multi-factorial disorder. Personality is a very important determining factor of drug dependence. Objectives: To find out the possible relationship between personality traits and substance use disorders. Methods: This was a descriptive, cross-sectional and case-control study conducted in the department of Psychiatry of Bangabandhu Sheikh Mujib Medical University and Central Drug Addiction Treatment Center, Dhaka for a period of one year (January 2005 to December 2005. From five hundred respondents, 250 had the history of substance use disorders selected as case, and equal number were age, sex, habitat and economic background matched controls were taken. Personality traits of both cases and control were measured by applying Eysenck Personality Questionnaire. Results: Mean ± SD psychoticism (8.42±3 vs 4.33±1.8, Neuroticism (11.89±2.3 vs 9.83±2 were significantly higher (P<0.01 in cases than controls. It was found that psychoticism was 2.3 times and neurticism was 1.7 times higher in substance users than that of controls. There were no significant differences of mean distribution of extroversion and lie scales among the cases & controls. This study also revealed that, there was no significant relationship between personality traits and different variables related to substance use except that psychoticism was significantly higher in those substance users who had have positive history of troubles with law than those having no history of trouble with law (8.82±3.2 & 7.95±2.7 respectively. Conclusion: Personality traits may have an influence on persons with substance use disorder which detoriates quality of life. Key words: Drug dependence; Personality; Psychoticism; Neuroticism; Extraversion; Lie scale. DOI: 10.3329/bsmmuj.v3i2.7056BSMMU J 2010; 3(2: 76-81

Maternal effects of the English grain aphids feeding on the wheat varieties with different resistance traits.

Science.gov (United States)

Hu, Xiang-Shun; Zhang, Zhan-Feng; Zhu, Tong-Yi; Song, Yue; Wu, Li-Juan; Liu, Xiao-Feng; Zhao, Hui-Yan; Liu, Tong-Xian

2018-05-09

The maternal effects of the English grain aphid, Sitobion avenae on offspring phenotypes and performance on wheat varieties with different resistance traits were examined. We found that both conditioning wheat varieties(the host plant for over 3 months) and transition wheat varieties affected the biological parameters of aphid offspring after they were transferred between wheat varieties with different resistance traits. The conditioning varieties affected weight gain, development time (DT), and the intrinsic rate of natural increase (r m ), whereas transition varieties affected the fecundity, r m , net reproductive rate, and fitness index. The conditioning and transition wheat varieties had significant interaction effects on the aphid offspring's DT, mean relative growth rate, and fecundity. Our results showed that there was obvious maternal effects on offspring when S. avenae transferred bwteen wheat varieties with different resistance level, and the resistance traits of wheat varieties could induce an interaction between the conditioning and transition wheat varieties to influence the growth, development, reproduction, and even population dynamics of S. avenae. The conditioning varieties affected life-history traits related to individual growth and development to a greater extent, whereas transition varieties affected fecundity and population parameters more.

Science on a salad plate?: Thinking about the representation of natural history in the Canadian Historic Dinner Service project.

Science.gov (United States)

Cronin, Keri

2008-01-01

The Women's Art Association of Canada marked the 400th anniversary of John Cabot's "discovery" of Canada (celebrated in 1897) through the production of the "Canadian Historic Dinner Service." The high-profile project, which resulted in a set of hand-painted porcelain dinnerware, was a celebration not only of nation-building, but also of the natural history of the country. Visual reference material provided to the women selected to create the individual pieces included photographs, natural history texts, and illustrations that W.H. Bartlett produced for Canadian Scenery earlier in the century. This article explores this visual reinterpretation of Canada's natural history in order to raise questions about how a recontextualization of scientific material shapes narratives of nation and nature in the 'New World'.

Toward a Predictive Framework for Convergent Evolution: Integrating Natural History, Genetic Mechanisms, and Consequences for the Diversity of Life.

Science.gov (United States)

Agrawal, Anurag A

2017-08-01

A charm of biology as a scientific discipline is the diversity of life. Although this diversity can make laws of biology challenging to discover, several repeated patterns and general principles govern evolutionary diversification. Convergent evolution, the independent evolution of similar phenotypes, has been at the heart of one approach to understand generality in the evolutionary process. Yet understanding when and why organismal traits and strategies repeatedly evolve has been a central challenge. These issues were the focus of the American Society of Naturalists Vice Presidential Symposium in 2016 and are the subject of this collection of articles. Although naturalists have long made inferences about convergent evolution and its importance, there has been confusion in the interpretation of the pattern of convergence. Does convergence primarily indicate adaptation or constraint? How often should convergence be expected? Are there general principles that would allow us to predict where and when and by what mechanisms convergent evolution should occur? What role does natural history play in advancing our understanding of general evolutionary principles? In this introductory article, I address these questions, review several generalizations about convergent evolution that have emerged over the past 15 years, and present a framework for advancing the study and interpretation of convergence. Perhaps the most important emerging conclusion is that the genetic mechanisms of convergent evolution are phylogenetically conserved; that is, more closely related species tend to share the same genetic basis of traits, even when independently evolved. Finally, I highlight how the articles in this special issue further develop concepts, methodologies, and case studies at the frontier of our understanding of the causes and consequences of convergent evolution.

Context-dependent effects of cold stress on behavioral, physiological, and life-history traits of the red flour beetle.

Science.gov (United States)

Scharf, Inon; Wertheimer, Keren-Or; Xin, Joy Lim; Gilad, Tomer; Goldenberg, Inna; Subach, Aziz

2017-06-20

Animals are exposed in nature to a variety of stressors. While stress is generally harmful, mild stress can also be beneficial and contribute to reproduction and survival. We studied the effect of five cold shock events versus a single cold shock and a control group, representing three levels of stress (harsh, mild, and no stress), on behavioral, physiological, and life-history traits of the red flour beetle (Tribolium castaneum, Herbst 1797). Beetles exposed to harsh cold stress were less active than a control group: they moved less and failed more frequently to detect a food patch. Their probability to mate was also lower. Beetle pairs exposed to harsh cold stress frequently failed to reproduce at all, and if reproducing, females laid fewer eggs, which were, as larvae in mid-development, smaller than those in the control group. However, harsh cold stress led to improved female starvation tolerance, probably due to enhanced lipid accumulation. Harsh cold shock also improved tolerance to an additional cold shock compared to the control. Finally, a single cold shock event negatively affected fewer measured response variables than the harsh cold stress, but also enhanced neither starvation tolerance nor tolerance to an additional cold shock. The consequences of a harsher cold stress are thus not solely detrimental but might even enhance survival under stressful conditions. Under benign conditions, nevertheless, harsh stress impedes beetle performance. The harsh stress probably shifted the balance point of the survival-reproduction trade-off, a shift that did not take place following exposure to mild stress. © 2017 Institute of Zoology, Chinese Academy of Sciences.

The natural history of ankylosing spondylitis in the 21st century

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C. Campana

2011-06-01

Full Text Available Ankylosing spondylitis (AS is a chronic inflammatory disease that affects the axial skeleton and evolves in stiffnes followed by ankylosis and disability. However, it may be difficult to exactly establish the natural history of the disease and the influence of risk factors of progression, since most patients are treated with various pharmacologic or non-pharmacologic agents, which may potentially influence the natural progression of the disease. In this context, we report here a very interesting case of a 40 year old man, presented to our outpatient clinic, 28 years after the onset of AS. Previously for personal reasons, did not choose not to undergo any treatment. This case allows us to evaluate the natural radiological progression of the disease and the influence of predictive risk factors.

Species traits and environmental constraints: entomological research and the history of ecological theory.

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Statzner, B; Hildrew, A G; Resh, V H

2001-01-01

The role that entomology has played in the historical (1800s-1970s) development of ecological theories that match species traits with environmental constraints is reviewed along three lineages originating from the ideas of a minister (Malthus TR. 1798. An Essay on the Principle of Population. London: Johnson) and a chemist (Liebig J. 1840. Die Organische Chemie in ihrer Anwendung auf Agricultur und Physiologie. Braunschweig: Vieweg). Major developments in lineage 1 focus on habitat as a filter for species traits, succession, nonequilibrium and equilibrium conditions, and generalizations about the correlation of traits to environmental constraints. In lineage 2, we trace the evolution of the niche concept and focus on ecophysiological traits, biotic interactions, and environmental conditions. Finally, we describe the conceptual route from early demographic studies of human and animal populations to the r-K concept in lineage 3. In the 1970s, the entomologist Southwood merged these three lineages into the "habitat templet concept" (Southwood TRE. 1977. J. Anim. Ecol. 46:337-65), which has stimulated much subsequent research in entomology and general ecology. We conclude that insects have been a far more important resource for the development of ecological theory than previously acknowledged.

Stereotactic Radiosurgery versus Natural History in Patients with Growing Vestibular Schwannomas.

Science.gov (United States)

Tu, Albert; Gooderham, Peter; Mick, Paul; Westerberg, Brian; Toyota, Brian; Akagami, Ryojo

2015-08-01

Objective To describe our experience with stereotactic radiosurgery and its efficacy on growing tumors, and then to compare this result with the natural history of a similar cohort of non-radiation-treated lesions. Study Design A retrospective chart review and cohort comparison. Methods The long-term control rates of patients having undergone radiosurgery were collected and calculated, and this population was then compared with a group of untreated patients from the same period of time with growing lesions. Results A total of 61 patients with growing vestibular schwannomas treated with radiosurgery were included. After a mean of 160 months, we observed a control rate of 85.2%. When compared with a group of 36 patients with growing tumors who were yet to receive treatment (previously published), we found a corrected control rate or relative risk reduction of only 76.8%. Conclusion Radiosurgery for growing vestibular schwannomas is less effective than previously reported in unselected series. Although radiosurgery still has a role in managing this disease, consideration should be given to the actual efficacy that may be calculated when the natural history is known. We hope other centers will similarly report their experience on this cohort of patients.

Life-history traits of the long-nosed skate Dipturus oxyrinchus.

Science.gov (United States)

Bellodi, A; Porcu, C; Cannas, R; Cau, Al; Marongiu, M F; Mulas, A; Vittori, S; Follesa, M C

2017-03-01

This work investigates life-history traits of the long-nosed skate Dipturus oxyrinchus, which is a common by-catch in Sardinian waters. The reproductive variables were analysed from 979 specimens sampled during scientific and commercial hauls. Females (10·4-117·5 cm total length, L T ) attained larger sizes than males (14·5-99·5 cm L T ). To evaluate age and growth, a sub-sample of 130 individuals (76 females and 54 males) were used. The age was estimated by annuli counts of sectioned vertebral centra. Four models were used for the length-at-age data: the von Bertalanffy, the exponential, the Gompertz and the logistic functions. According to the Akaike's information criterion, the Gompertz model seemed to provide the best fitting curve (L ∞ mean ± s.e.: 127·55 ± 4·90 cm, k: 0·14 ± 0·09, IP: 3·97 ± 0·90 years). The oldest female and male were aged 17 (115·5 cm L T ) and 15 years (96·0 cm L T ), respectively. Lengths at maturity were 103·5 cm for females and 91·0 cm for males, corresponding to 90% of the maximum observed length in both sexes. The monthly distribution of maturity stages highlighted an extended reproductive cycle, with spawning females and active males being present almost throughout the year, as confirmed by the gonado-somatic index. Ovarian fecundity reached a maximum of 26 yolked follicles with a mean ± s.e. size of 19·7 ± 6·5 mm. © 2016 The Fisheries Society of the British Isles.

Disparate relatives: Life histories vary more in genera occupying intermediate environments

NARCIS (Netherlands)

Hermant, M.; Hennion, F.; Bartish, I.V.; Yguel, B.; Prinzing, A.

2012-01-01

Species within clades are commonly assumed to share similar life history traits, but within a given region some clades show much greater variability in traits than others. Are variable clades older, allowing more time for trait diversification? Or do they occupy particular environments, providing a

Production traits of artificially and naturally hatched geese in intensive and free-range systems - II: slaughter, carcass and meat quality traits.

Science.gov (United States)

Boz, M A; Sarıca, M; Yamak, U S

2017-04-01

1. This study investigates the slaughter, carcass and meat quality traits of artificially and naturally hatched geese in intensive and free-range production systems. 2. The study was conducted with 114 naturally hatched and 102 artificially hatched geese. From each replicate of the intensive and free-range systems, one female and one male goose were slaughtered at the ages of 14, 16 and 18 weeks (a total of 32 geese per slaughter week). 3. Artificially hatched geese had higher slaughter weights (5280 vs. 4404 g), carcass weights (3520 vs. 2863), dressing percentages (66.6-65.2% vs. 65.0-63.6%) and carcass part, feather and edible inner organ weights. The ratio of both edible inner organs and abdominal fat was higher in naturally hatched geese. Breast meat L*, a* and pH values and thigh meat dry matter values were higher in artificially hatched geese, whereas thigh meat b* and pH values were higher in naturally hatched geese. 4. Intensively reared geese had higher slaughter weights (4900 vs. 4783 g), carcass weights (3253 vs. 3130 g) and abdominal fat weights (280 vs. 250 g), as well as higher dressing percentages (66.3-64.9% vs. 65.3-63.9%). Breast meat b* and thigh meat L* values were higher in the intensive system, while breast and thigh pH values, dripping loss and cooking loss were higher in the free-range system. Water-holding capacity was higher in the intensive system. 5. In conclusion, artificially hatched, intensively reared geese had the highest slaughter weights; however, both artificially and naturally hatched geese raised in a free-range system reached acceptable slaughter weights and can thus be recommended for use with this type of production system.

Induced defences alter the strength and direction of natural selection on reproductive traits in common milkweed.

Science.gov (United States)

Thompson, K A; Cory, K A; Johnson, M T J

2017-06-01

Evolutionary biologists have long sought to understand the ecological processes that generate plant reproductive diversity. Recent evidence indicates that constitutive antiherbivore defences can alter natural selection on reproductive traits, but it is unclear whether induced defences will have the same effect and whether reduced foliar damage in defended plants is the cause of this pattern. In a factorial field experiment using common milkweed, Asclepias syriaca L., we induced plant defences using jasmonic acid (JA) and imposed foliar damage using scissors. We found that JA-induced plants experienced selection for more inflorescences that were smaller in size (fewer flowers), whereas control plants only experienced a trend towards selection for larger inflorescences (more flowers); all effects were independent of foliar damage. Our results demonstrate that induced defences can alter both the strength and direction of selection on reproductive traits, and suggest that antiherbivore defences may promote the evolution of plant reproductive diversity. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

Generation time, life history and the substitution rate of neutral mutations.

Science.gov (United States)

Lehtonen, Jussi; Lanfear, Robert

2014-11-01

Our understanding of molecular evolution is hampered by a lack of quantitative predictions about how life-history (LH) traits should correlate with substitution rates. Comparative studies have shown that neutral substitution rates vary substantially between species, and evidence shows that much of this diversity is associated with variation in LH traits. However, while these studies often agree, some unexplained and contradictory results have emerged. Explaining these results is difficult without a clear theoretical understanding of the problem. In this study, we derive predictions for the relationships between LH traits and substitution rates in iteroparous species by using demographic theory to relate commonly measured life-history traits to genetic generation time, and by implication to neutral substitution rates. This provides some surprisingly simple explanations for otherwise confusing patterns, such as the association between fecundity and substitution rates. The same framework can be applied to more complex life histories if full life-tables are available. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

78 FR 19299 - Notice of Inventory Completion: Slater Museum of Natural History, University of Puget Sound...

Science.gov (United States)

2013-03-29

... DEPARTMENT OF THE INTERIOR National Park Service [NPS-WASO-NAGPRA-12395; PPWOCRADN0-PCU00RP14.R50000] Notice of Inventory Completion: Slater Museum of Natural History, University of Puget Sound... History, University of Puget Sound, has completed an inventory of human remains in consultation with the...

[Spleen autotransplant. Natural history and description of a case].

Science.gov (United States)

Ceccherini, E; Sereni, P; Ferrari, F; Fagioli Zucchi, A; Croce, F; Di Maggio, G; Vattimo, A; Mancini, S

1989-09-30

After considering the natural history of spleen auto-transplant, a clinical case followed up for seven months with instrumental (echography, scintigraphy) and humoral (Jolly bodies, Heinz bodies, reticulocytes, platelets, complement, immune globulin) examinations has been considered so as to verify "take" and function. One months after reimplantation the patient was again operated on for the onset of an intestinal occlusion due to adherences. On that occasion it was possible to control that the implant had taken. It is concluded that personally used parameters proved to be well correlated and that scintigraphy and echography are two complementary, effective techniques for monitoring auto-transplants.

Using History of Science to Teach Nature of Science to Elementary Students

Science.gov (United States)

Fouad, Khadija E.; Masters, Heidi; Akerson, Valarie L.

2015-01-01

Science lessons using inquiry only or history of science with inquiry were used for explicit reflective nature of science (NOS) instruction for second-, third-, and fourth-grade students randomly assigned to receive one of the treatments. Students in both groups improved in their understanding of creative NOS, tentative NOS, empirical NOS, and…

Old world versus new world: life-history alterations in a successful invader introduced across Europe.

Science.gov (United States)

Fox, Michael G; Copp, Gordon H

2014-02-01

We examined differences in pumpkinseed (Lepomis gibbosus) life-history traits between native North American and introduced European populations, and tested three life-history predictions related to the effect of temperature, growth, waterbody size, and the presence/absence of predators on native and non-native populations. Pumpkinseed populations exhibit more 'opportunistic' traits (earlier maturity, smaller size at maturity, and higher reproductive allocation) in their introduced European range than those in their native range. Predictions of life-history traits were improved when indicators of juvenile growth rate (mean length at age 2), waterbody size (surface area), and thermal regime (air temperature degree-days above 10 °C) were incorporated into models along with continental location, but European pumpkinseed populations exhibit more opportunistic life-history traits than North American populations even when these factors are accounted for. Native pumpkinseed in waterbodies containing piscivores mature later and at a larger size, and have lower gonadosomatic indices than those in waterbodies lacking piscivores, whereas there is no significant difference in the same three life-history traits between European waterbodies containing or lacking piscivores. Because congeneric competitors of the pumpkinseed are absent from Europe, the apparent absence of a predator life-history effect there could also be due to the absence of the major sunfish competitors. In either case, the evolution and maintenance of more opportunistic traits in European pumpkinseed can likely be attributed to enemy release, and this may explain the successful establishment and spread of pumpkinseed in many parts of Europe.

Bringing dinosaurs back to life: exhibiting prehistory at the American Museum of Natural History.

Science.gov (United States)

Rieppel, Lukas

2012-09-01

This essay examines the exhibition of dinosaurs at the American Museum of Natural History during the first two decades of the twentieth century. Dinosaurs provide an especially illuminating lens through which to view the history of museum display practices for two reasons: they made for remarkably spectacular exhibits; and they rested on contested theories about the anatomy, life history, and behavior of long-extinct animals to which curators had no direct observational access. The American Museum sought to capitalize on the popularity of dinosaurs while mitigating the risks of mounting an overtly speculative display by fashioning them into a kind of mixed-media installation made of several elements, including fossilized bone, shellac, iron, and plaster. The resulting sculptures provided visitors with a vivid and lifelike imaginative experience. At the same time, curators, who were anxious to downplay the speculative nature of mounted dinosaurs, drew systematic attention to the material connection that tied individual pieces of fossilized bone to the actual past. Freestanding dinosaurs can therefore be read to have functioned as iconic sculptures that self-consciously advertised their indexical content.

Henry D. Thoreau. Wild Apples and Other Natural History Essays.

Directory of Open Access Journals (Sweden)

Michel Granger

2006-04-01

Full Text Available Ce recueil inclut les divers essais que Thoreau a consacrés à la nature pendant une vingtaine d’années et qui ont été publiés précédemment sous le titre inexact d’Excursions (1962 : « Natural History of Massachusetts », « A Walk to Wachusett », « A Winter Walk », « Walking », « The Succession of Forest Trees », « Autumnal Tints », « Wild Apples » ; il ajoute « Huckleberrie », projet de conférence tardif, publié seulement en 1970. Le texte a été soigneusement mis au point par William Rossi, l...

The evolution of coloniality in birds in relation to food, habitat, predation, and life-history traits: a comparative analysis.

Science.gov (United States)

Rolland, C; Danchin, E; de Fraipont, M

1998-06-01

Coloniality in birds has been intensively studied under the cost and benefit approach, but no general conclusion can be given concerning its evolutionary function. Here, we report on a comparative analysis carried out on 320 species of birds using the general method of comparative analysis for discrete variables and the contrast method to analyze the evolution of coloniality. Showing a mean of 23 convergences and 10 reversals, coloniality appears to be a rather labile trait. Colonial breeding appears strongly correlated with the absence of feeding territory, the aquatic habitat, and nest exposure to predators but was not correlated with changes in life-history traits (body mass and clutch size). The correlation of coloniality with the aquatic habitat is in fact explained by a strong correlation with the marine habitat. Unexpectedly, we found that the evolution toward a marine habitat in birds was contingent on coloniality and that coloniality evolved before the passage to a marine life. These results-along with the lack of transitions from the nonmarine to marine habitat in solitary species and the precedence of the loss of feeding territoriality on the passage to a marine life-contradict most of the hypotheses classically accepted to explain coloniality and suggest that we use a different framework to study this evolutionary enigma.

Ecological interactions drive evolutionary loss of traits.

Science.gov (United States)

Ellers, Jacintha; Kiers, E Toby; Currie, Cameron R; McDonald, Bradon R; Visser, Bertanne

2012-10-01

Loss of traits can dramatically alter the fate of species. Evidence is rapidly accumulating that the prevalence of trait loss is grossly underestimated. New findings demonstrate that traits can be lost without affecting the external phenotype, provided the lost function is compensated for by species interactions. This is important because trait loss can tighten the ecological relationship between partners, affecting the maintenance of species interactions. Here, we develop a new perspective on so-called `compensated trait loss' and how this type of trait loss may affect the evolutionary dynamics between interacting organisms. We argue that: (1) the frequency of compensated trait loss is currently underestimated because it can go unnoticed as long as ecological interactions are maintained; (2) by analysing known cases of trait loss, specific factors promoting compensated trait loss can be identified and (3) genomic sequencing is a key way forwards in detecting compensated trait loss. We present a comprehensive literature survey showing that compensated trait loss is taxonomically widespread, can involve essential traits, and often occurs as replicated evolutionary events. Despite its hidden nature, compensated trait loss is important in directing evolutionary dynamics of ecological relationships and has the potential to change facultative ecological interactions into obligatory ones. © 2012 Blackwell Publishing Ltd/CNRS.

Maternal Care, Maltreatment and Callous-Unemotional Traits among Urban Male Juvenile Offenders

Science.gov (United States)

Kimonis, Eva R.; Cross, Brittany; Howard, Aisha; Donoghue, Kathleen

2013-01-01

Callous-unemotional (CU) traits (i.e., lack of empathy/guilt, uncaring attitudes) are believed to be a developmental antecedent to adult psychopathy and identify antisocial youth at risk for severe and persistent aggression. The psychosocial histories of antisocial and aggressive individuals with psychopathic traits are characterized by abusive or…

Contribución a la historia natural de los tigres marcianos [Contribution to the Natural History of Martian tigers

Directory of Open Access Journals (Sweden)

Gustavo Caponi

2018-01-01

Full Text Available En las coordenadas conceptuales que efectivamente pautan el desarrollo de las ciencias biológicas podemos encontrar claves capaces de guiar al pensamiento cuando éste enfrenta escenarios contrafactuales alternativos a lo efectivamente ocurrido. En lo que respecta a ese tópico, la distinción entre una entidad individual y la función que esa entidad puede venir a desempeñar en un determinado proceso o sistema, merece ser destacada como uno de los mayores rendimientos que puede darnos el examen de los marcos teóricos que efectivamente guían el desarrollo de la Biología. A primera vista, estos pueden parecer estrechos, y demasiado apegados a la concreción como para poder enfrentar una Historia Natural de los mundos posibles, pero no lo son. Todo lo que puede caber en esa historia contrafáctica, ya tiene su correlato en la Historia Natural efectiva del mundo que nos rodea; y el pensamiento biológico se desarrolló para enfrentar los desafíos que eso conlleva.   [In the conceptual framework, that effectively guides the development of biological sciences, we can find keys able for guiding thought when it faces alternative counterfactual scenarios to what has actually occurred. Concerning this issue, the distinction between an individual entity and the function which that that may come to play in a particular process or system, deserves to be highlighted as one of the conceptual resulting from the examination of the theoretical backgrounds that effectively guide the development of Biology. At first glance, these theoretical backgrounds may seem narrow and too attached to the concreteness, to be able for face a Natural History of possible worlds, but they are not. All that can fit in that counterfactual History already has its correlate in the actual Natural History of the world surrounding us; and biological thinking growth to face the challenges that this entails.

Seascape and life-history traits do not predict self-recruitment in a coral reef fish

KAUST Repository

Herrera Sarrias, Marcela

2016-08-10

The persistence and resilience of many coral reef species are dependent on rates of connectivity among sub-populations. However, despite increasing research efforts, the spatial scale of larval dispersal remains unpredictable for most marine metapopulations. Here, we assess patterns of larval dispersal in the angelfish Centropyge bicolor in Kimbe Bay, Papua New Guinea, using parentage and sibling reconstruction analyses based on 23 microsatellite DNA loci. We found that, contrary to previous findings in this system, self-recruitment (SR) was virtually absent at both the reef (0.4-0.5% at 0.15 km2) and the lagoon scale (0.6-0.8% at approx. 700 km2). While approximately 25%of the collected juveniles were identified as potential siblings, the majority of sibling pairs were sampled from separate reefs. Integrating our findings with earlier research from the same system suggests that geographical setting and life-history traits alone are not suitable predictors of SR and that high levels of localized recruitment are not universal in coral reef fishes. © 2016 The Authors.

Perrault, Buffon and the natural history of animals

Science.gov (United States)

Guerrini, Anita

2012-01-01

In 1733, as part of a programme to publish its early works in a uniform format, the Paris Academy of Sciences reprinted Mémoires pour servir à l'histoire naturelle des animaux (Histoire des animaux), last published in 1676, a work of both natural history and mechanistic anatomy. However, unlike the other works in this enterprise, Histoire des animaux was extensively edited and updated. In 1749 Georges-Louis Leclerc de Buffon published the first volume of Histoire naturelle. Its volumes on quadrupeds, written with Louis-Jean-Marie Daubenton, held significant similarities to Histoire des animaux. The relationship between these works has not hitherto been examined. Buffon's early ideas on species, in particular, resemble the emphasis on particulars of Histoire des animaux.

Life history strategies of fish species and biodiversity in eastern USA streams

Science.gov (United States)

Meador, Michael R.; Brown, Larry M.

2015-01-01

Predictive models have been used to determine fish species that occur less frequently than expected (decreasers) and those that occur more frequently than expected (increasers) in streams in the eastern U.S. Coupling life history traits with 51 decreaser and 38 increaser fish species provided the opportunity to examine potential mechanisms associated with predicted changes in fish species distributions in eastern streams. We assigned six life history traits – fecundity, longevity, maturation age, maximum total length, parental care, and spawning season duration – to each fish species. Decreaser species were significantly smaller in size and shorter-lived with reduced fecundity and shorter spawning seasons compared to increaser species. Cluster analysis of traits revealed correspondence with a life history model defining equilibrium (low fecundity, high parental care), opportunistic (early maturation, low parental care), and periodic (late maturation, high fecundity, low parental care) end-point strategies. Nearly 50 % of decreaser species were associated with an intermediate opportunistic-periodic strategy, suggesting that abiotic factors such as habitat specialization and streamflow alteration may serve as important influences on life history traits and strategies of decreaser species. In contrast, the percent of increaser species among life history strategy groups ranged from 21 to 32 %, suggesting that life history strategies of increaser species were more diverse than those of decreaser species. This study highlights the utility of linking life history theory to biodiversity to better understand mechanisms that contribute to fish species distributions in the eastern U.S.

The natural history of anencephaly.

LENUS (Irish Health Repository)

Obeidi, Nidaa

2012-01-31

OBJECTIVE: Early elective termination of pregnancy is the most common outcome of a diagnosis of anencephaly in developed countries. Experience and expertise with management of ongoing pregnancies is limited. We aimed to investigate the natural history of these pregnancies from diagnosis to delivery and to determine timing of death. METHOD: A retrospective review of cases of anencephaly diagnosed between 2003 and 2009 in tertiary-referral university teaching hospitals in Cork. RESULTS: The majority of cases (25\\/26; 96%) were diagnosed prenatally at a median gestation of 21(+2) weeks (range 13(+4)-32(+4)). The median maternal age was 30 years (range 17-41) and 50% were primigravidae. Seven pregnancies were complicated by polyhydramnios and four deliveries were complicated by shoulder dystocia. The median gestation at delivery was 35 weeks (range 22(+5)-42(+6)); 69% of labours were induced at a median gestation of 34 weeks. Six women (6\\/26; 23%) had a pre-labour intrauterine fetal death and nine women (9\\/26; 35%) had an intrapartum fetal death. Median neonatal survival time was 55 min (range 10 min to 8 days). Six parents donated neonatal organs for transplantation. CONCLUSION: This study provides useful information for health professionals caring for patients with a diagnosis of anencephaly. The majority of these infants die prior to delivery but short-term survival is possible.

Ionizing radiations in the natural history of the Earth: role of supernova flares

International Nuclear Information System (INIS)

Byakov, V.M.

1996-01-01

Paper discusses the role of supernova flares in the natural history of the Earth. Probability of the solar system occurrence in the residual of supernova explosion is estimated Possible effects of the Earth occurrence in the supernova residual are studied. 29 refs., 3 tabs

The definition and natural history of severe exacerbation of hepatitis B

Directory of Open Access Journals (Sweden)

GUO Wei

2014-10-01

Full Text Available Despite different opinions on its definition and classification in the past, a consensus has gradually been reached regarding the naming, classification, and clinical diagnosis of liver failure. The classification of liver failure is described, and the definition and natural history of severe exacerbation of hepatitis B are summarized. Antiviral treatment and artificial liver support in the early stage are beneficial for clinical outcomes and prognosis.

Condition-dependent trade-offs between sexual traits, body condition and immunity: the effect of novel habitats.

Science.gov (United States)

Iglesias-Carrasco, Maider; Head, Megan L; Jennions, Michael D; Cabido, Carlos

2016-06-21

The optimal allocation of resources to sexual signals and other life history traits is usually dependent on an individual's condition, while variation in the expression of sexual traits across environments depends on the combined effects of local adaptation, mean condition, and phenotypic responses to environment-specific cues that affect resource allocation. A clear contrast can often be drawn between natural habitats and novel habitats, such as forest plantations and urban areas. In some species, males seem to change their sexual signals in these novel environments, but why this occurs and how it affects signal reliability is still poorly understood. The relative size of sexual traits and level of immune responses were significantly lower for male palmate newts Lissotriton helveticus caught in pine and eucalyptus plantations compared to those caught in native forests, but there was no habitat-dependent difference in body condition (n = 18 sites, 382 males). The reliability with which sexual traits signalled body condition and immune responses was the same in all three habitats. Finally, we conducted a mesocosm experiment in which males were maintained in pine, eucalypt or oak infused water for 21 days. Males in plantation-like water (pine or eucalypt) showed significantly lower immune responses but no change in body condition. This matches the pattern seen for field-caught males. Unlike field-caught males, however, there was no relationship between water type and relative sexual trait size. Pine and eucalyptus plantations are likely to be detrimental to male palmate newt because they are associated with reduced immune function and smaller sexual traits. This could be because ecological aspects of these novel habitats, such as high water turbidity or changes in male-male competition, drive selection for reduced investment into sexual traits. However, it is more probable that there are differences in the ease of acquisition, hence optimal allocation, of

Natural history of chondroid skull base lesions - case report and review

International Nuclear Information System (INIS)

Schmidinger, A.; Rosahl, S.K.; Vorkapic, P.; Samii, M.

2002-01-01

Long-term follow-up reports on chondroid lesions of the skull base are rarely presented in the literature. There are virtually no data on natural growth rates of these tumors based on MRI obtained over a period of 10 years or longer. We followed a patient who has had such a lesion for more than 12 years. A non-progressive, slight abducens palsy has been the only associated symptom so far. Even though the patient was operated on for an additional intracranial arterio-venous malformation, clinical features and chromosomal testing excluded Maffucci's syndrome. The MRI follow-up in this case provides an extraordinary perspective on the natural history of chondroid skull base tumors. (orig.)

The Classification, Natural History and Treatment of the Limb Girdle Muscular Dystrophies.

Science.gov (United States)

Murphy, Alexander Peter; Straub, Volker

2015-07-22

Over sixty years ago John Walton and Frederick Nattrass defined limb girdle muscular dystrophy (LGMD) as a separate entity from the X-linked dystrophinopathies such as Duchenne and Becker muscular dystrophies. LGMD is a highly heterogeneous group of very rare neuromuscular disorders whose common factor is their autosomal inheritance. Sixty years later, with the development of increasingly advanced molecular genetic investigations, a more precise classification and understanding of the pathogenesis is possible.To date, over 30 distinct subtypes of LGMD have been identified, most of them inherited in an autosomal recessive fashion. There are significant differences in the frequency of subtypes of LGMD between different ethnic populations, providing evidence of founder mutations. Clinically there is phenotypic heterogeneity between subtypes of LGMD with varying severity and age of onset of symptoms. The first natural history studies into subtypes of LGMD are in process, but large scale longitudinal data have been lacking due to the rare nature of these diseases. Following natural history data collection, the next challenge is to develop more effective, disease specific treatments. Current management is focussed on symptomatic and supportive treatments. Advances in the application of new omics technologies and the generation of large-scale biomedical data will help to better understand disease mechanisms in LGMD and should ultimately help to accelerate the development of novel and more effective therapeutic approaches.

Marine Sciences: from natural history to ecology and back, on Darwin's shoulders

Directory of Open Access Journals (Sweden)

Ferdinando Boero

2010-12-01

Full Text Available The naturalist Charles Darwin founded modern ecology, considering in a single conceptual framework the manifold aspects regarding the organization of life at various levels of complexity and its relationship with the physical world. The development of powerful analytical tools led to abandon Darwin's natural history and to transform naturalists, as Darwin labelled himself, into the practitioners of more focused disciplines, aimed at tackling specific problems that considered the various aspects of the organization of life in great detail but, also, in isolation from each other. Among the various disciplines that stemmed from the Darwinian method, ecology was further split into many branches, and marine ecology was no exception. The compartmentalization of the marine realm into several sub-domains (e.g., plankton, benthos, nekton led to neglect of the connections linking the various parts that were separated for the ease of analyses that, in this way, prevented synthetic visions. The way marine sciences were studied also led to separate visions depending on the employed tools, so that ship-based biological oceanography developed almost separately from marine station-based marine biology. The necessity of putting together such concepts as biodiversity and ecosystem functioning is rapidly leading to synthetic approaches that re-discover the historical nature of ecology, leading to the dawn of a new natural history.

Effects of environmental changes on natural selection active on human polygenic traits.

Science.gov (United States)

Ulizzi, L

1993-06-01

During the last century, industrialized countries experienced such an improvement in socioeconomic conditions and in sanitation that it is likely that the selective forces active on human metric traits have been modified. Perinatal mortality as a function of birth weight is one of the clearest examples of natural selection in humans. Here, trends over time of stabilizing and directional selection associated with birth weight have been analyzed in Japan from 1969 to 1989. The population of newborns has been subdivided according to gestational age, which is one of the main covariates of birth weight. The results show that in full-term babies both stabilizing and directional selection are coming to an end, whereas in babies born after 8 months of gestation these selective forces are still active, even if at much lower levels than in the past. The peculiar results found in the 7-month-gestation population are probably due to grossly abnormal cases of immaturity.

What was historical about natural history? Contingency and explanation in the science of living things.

Science.gov (United States)

Harrison, Peter

2016-08-01

There is a long-standing distinction in Western thought between scientific and historical modes of explanation. According to Aristotle's influential account of scientific knowledge there cannot be an explanatory science of what is contingent and accidental, such things being the purview of a descriptive history. This distinction between scientia and historia continued to inform assumptions about scientific explanation into the nineteenth century and is particularly significant when considering the emergence of biology and its displacement of the more traditional discipline of natural history. One of the consequences of this nineteenth-century transition was that while modern evolutionary theory retained significant, if often implicit, historical components, these were often overlooked as evolutionary biology sought to accommodate itself to a model of scientific explanation that involved appeals to laws of nature. These scientific aspirations of evolutionary biology sometimes sit uncomfortably with its historical dimension. This tension lies beneath recent philosophical critiques of evolutionary theory and its modes of explanation. Such critiques, however, overlook the fact that there are legitimate modes of historical explanation that do not require recourse to laws of nature. But responding to these criticisms calls for a more explicit recognition of the affinities between evolutionary biology and history. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Impact of chronic kidney disease on the natural history of alkaptonuria

Science.gov (United States)

Faria, Bernardo; Vidinha, Joana; Pêgo, Cátia; Correia, Hugo; Sousa, Tânia

2012-01-01

In alkaptonuria, deficiency of homogentisate 1,2-dioxygenase leads to the accumulation of homogentisic acid (HGA) and its metabolites in the body, resulting in ochronosis. Reports of patients with alkaptonuria who have decreased kidney function are rare, but this seems to play an important role in the natural history of the disease. We describe a 68-year-old female with chronic kidney disease (CKD) of unknown etiology who started peritoneal dialysis (PD) after 5 years of follow-up and who was diagnosed with alkaptonuria at this time. Progressive exacerbation of ochronotic manifestations had been noted during these last few years, as kidney function worsened. After PD initiation, the disease continued to progress, and death occurred after one year and a half, due to severe aortic stenosis-related complications. Her 70-year-old sister was evaluated and also diagnosed with alkaptonuria. She had no renal dysfunction. Higher HGA excretion and significantly milder ochronosis than that of her sister were found. We present two alkaptonuric sisters with similar comorbidities except for the presence of CKD, who turned out to have totally different evolutions of their disease. This report confirms that kidney dysfunction may be an important factor in determining the natural history of alkaptonuria. PMID:25874097

Natural history and the formation of the human being: Kant on active forces.

Science.gov (United States)

Waldow, Anik

2016-08-01

In his 1785-review of the Ideen zur Philosophie der Geschichte der Menschheit, Kant objects to Herder's conception of nature as being imbued with active forces. This attack is usually evaluated against the background of Kant's critical project and his epistemological concern to caution against the "metaphysical excess" of attributing immanent properties to matter. In this paper I explore a slightly different reading by investigating Kant's pre-critical account of creation and generation. The aim of this is to show that Kant's struggle with the forces of matter has a long history and revolves around one central problem: that of how to distinguish between the non-purposive forces of nature and the intentional powers of the mind. Given this history, the epistemic stricture that Kant's critical project imposes on him no longer appears to be the primary reason for his attack on Herder. It merely aggravates a problem that Kant has been battling with since his earliest writings. Copyright © 2016 Elsevier Ltd. All rights reserved.

Initial report of the osteogenesis imperfecta adult natural history initiative.

Science.gov (United States)

Tosi, Laura L; Oetgen, Matthew E; Floor, Marianne K; Huber, Mary Beth; Kennelly, Ann M; McCarter, Robert J; Rak, Melanie F; Simmonds, Barbara J; Simpson, Melissa D; Tucker, Carole A; McKiernan, Fergus E

2015-11-14

A better understanding of the natural history of osteogenesis imperfecta (OI) in adulthood should improve health care for patients with this rare condition. The Osteogenesis Imperfecta Foundation established the Adult Natural History Initiative (ANHI) in 2010 to give voice to the health concerns of the adult OI community and to begin to address existing knowledge gaps for this condition. Using a web-based platform, 959 adults with self-reported OI, representing a wide range of self-reported disease severity, reported symptoms and health conditions, estimated the impact of these concerns on present and future health-related quality of life (QoL) and completed a Patient-Reported Outcomes Measurement Information System (PROMIS®) survey of health issues. Adults with OI report lower general physical health status (p report generally similar mental health status. Musculoskeletal, auditory, pulmonary, endocrine, and gastrointestinal issues are particular future health-related QoL concerns for these adults. Numerous other statistically significant differences exist among adults with OI as well as between adults with OI and the referent PROMIS® population, but the clinical significance of these differences is uncertain. Adults with OI report lower general health status but are otherwise more similar to the general population than might have been expected. While reassuring, further analysis of the extensive OI-ANHI databank should help identify areas of unique clinical concern and for future research. The OI-ANHI survey experience supports an internet-based strategy for successful patient-centered outcomes research in rare disease populations.

A Qualitative Natural History Study of ME/CFS in the Community

OpenAIRE

Anderson, Valerie R.; Jason, Leonard A.; Hlavaty, Laura E.

2013-01-01

In previous qualitative research on Myalgic Encephalomyelitis/chronic fatigue syndrome (ME/CFS), researchers have focused on the experiences of patients with ME/CFS in tertiary care samples, which limit the representativeness of the findings to those with access to health care. This qualitative study examined the natural history of a community-based sample of people with ME/CFS. Participants (n=19) were categorized into persisting, incidence, or remitting groups based on their reported illnes...

Putting the five-factor model into context: evidence linking big five traits to narrative identity.

Science.gov (United States)

Raggatt, Peter

2006-10-01

The study examined relationships between the Big Five personality traits and thematic content extracted from self-reports of life history data. One hundred and five "mature age" university students (M=30.1 years) completed the NEO PI-R trait measure, and the Personality Web Protocol. The protocol examines constituents of identity by asking participants to describe 24 key "attachments" from their life histories (significant events, people, places, objects, and possessions). Participants sorted these attachments into clusters and provided a self-descriptive label for each cluster (e.g., "adventurous self"). It was predicted that the thematic content of these cluster labels would be systematically related to Big Five trait scores (e.g., that labels referring to strength or positive emotions would be linked to Extraversion). The hypothesized links were obtained for each of the Big Five trait domains except Conscientiousness. Results are discussed with a view to broadening our understanding of the Five-Factor Model in relation to units of personality other than traits.

Population transcriptomics of life-history variation in the genus Salmo

DEFF Research Database (Denmark)

Giger, T.; Excoffier, L.; Amstutz, U.

2008-01-01

with physiological changes that are likely to be involved in preadaptations to seawater in anadromous populations of the genus Salmo, one of which was identified to encode for nucleophosmin 1. Our findings thus provide new molecular insights into salmonid life-history variation, opening new perspectives in the study......In this study, we demonstrate the power of applying complementary DNA (cDNA) microarray technology to identifying candidate loci that exhibit subtle differences in expression levels associated with a complex trait in natural populations of a nonmodel organism. Using a highly replicated experimental...... design involving 180 cDNA microarray experiments, we measured gene-expression levels from 1098 transcript probes in 90 individuals originating from six brown trout (Salmo trutta) and one Atlantic salmon (Salmo salar) population, which follow either a migratory or a sedentary life history. We identified...

Leaf traits within communities: context may affect the mapping of traits to function.

Science.gov (United States)

Funk, Jennifer L; Cornwell, William K

2013-09-01

The leaf economics spectrum (LES) has revolutionized the way many ecologists think about quantifying plant ecological trade-offs. In particular, the LES has connected a clear functional trade-off (long-lived leaves with slow carbon capture vs. short-lived leaves with fast carbon capture) to a handful of easily measured leaf traits. Building on this work, community ecologists are now able to quickly assess species carbon-capture strategies, which may have implications for community-level patterns such as competition or succession. However, there are a number of steps in this logic that require careful examination, and a potential danger arises when interpreting leaf-trait variation among species within communities where trait relationships are weak. Using data from 22 diverse communities, we show that relationships among three common functional traits (photosynthetic rate, leaf nitrogen concentration per mass, leaf mass per area) are weak in communities with low variation in leaf life span (LLS), especially communities dominated by herbaceous or deciduous woody species. However, globally there are few LLS data sets for communities dominated by herbaceous or deciduous species, and more data are needed to confirm this pattern. The context-dependent nature of trait relationships at the community level suggests that leaf-trait variation within communities, especially those dominated by herbaceous and deciduous woody species, should be interpreted with caution.

Primates and the Evolution of Long-Slow Life Histories

Science.gov (United States)

Jones, James Holland

2011-01-01

Summary Primates are characterized by relatively late ages at first reproduction, long lives and low fertility. Together, these traits define a life-history of reduced reproductive effort. Understanding the optimal allocation of reproductive effort, and specifically reduced reproductive effort, has been one of the key problems motivating the development of life history theory. Because of their unusual constellation of life-history traits, primates play an important role in the continued development of life history theory. In this review, I present the evidence for the reduced reproductive effort life histories of primates and discuss the ways that such life-history tactics are understood in contemporary theory. Such tactics are particularly consistent with the predictions of stochastic demographic models, suggesting a key role for environmental variability in the evolution of primate life histories. The tendency for primates to specialize in high-quality, high-variability food items may make them particularly susceptible to environmental variability and explain their low reproductive-effort tactics. I discuss recent applications of life history theory to human evolution and emphasize the continuity between models used to explain peculiarities of human reproduction and senescence with the long, slow life histories of primates more generally. PMID:21959161

Ex-situ evaluation of morphological, agronomic and qualitative traits of a naturalized population of parsley (Petroselinum crispum (Mill Nyman

Directory of Open Access Journals (Sweden)

Fusani, Pietro

2016-07-01

Full Text Available A naturalized population of parsley of the province of Trento, Italy, was evaluated ex-situ for its morphological and agronomic traits in a field trial in which it was compared with three commercial cultivars of the species. The naturalized population belongs to the smooth leaf type for the absence of curling, and differed from the other smooth leaf type accessions for the lower plant height, the smaller length of petiole and the prostrate attitude of the plant, all undesirable characteristics which make the harvest of plants more difficult. The yields of aerial parts and leaves were higher in the commercial cultivars, while the naturalized population had the highest yield and content of essential oil. Due to the high content and yield of essential oil, the naturalized population could be the object of an eventual breeding program aiming to improve the morphologic and agronomic undesirable characteristics.

Genetic Characterization of Dog Personality Traits.

Science.gov (United States)

Ilska, Joanna; Haskell, Marie J; Blott, Sarah C; Sánchez-Molano, Enrique; Polgar, Zita; Lofgren, Sarah E; Clements, Dylan N; Wiener, Pamela

2017-06-01

The genetic architecture of behavioral traits in dogs is of great interest to owners, breeders, and professionals involved in animal welfare, as well as to scientists studying the genetics of animal (including human) behavior. The genetic component of dog behavior is supported by between-breed differences and some evidence of within-breed variation. However, it is a challenge to gather sufficiently large datasets to dissect the genetic basis of complex traits such as behavior, which are both time-consuming and logistically difficult to measure, and known to be influenced by nongenetic factors. In this study, we exploited the knowledge that owners have of their dogs to generate a large dataset of personality traits in Labrador Retrievers. While accounting for key environmental factors, we demonstrate that genetic variance can be detected for dog personality traits assessed using questionnaire data. We identified substantial genetic variance for several traits, including fetching tendency and fear of loud noises, while other traits revealed negligibly small heritabilities. Genetic correlations were also estimated between traits; however, due to fairly large SEs, only a handful of trait pairs yielded statistically significant estimates. Genomic analyses indicated that these traits are mainly polygenic, such that individual genomic regions have small effects, and suggested chromosomal associations for six of the traits. The polygenic nature of these traits is consistent with previous behavioral genetics studies in other species, for example in mouse, and confirms that large datasets are required to quantify the genetic variance and to identify the individual genes that influence behavioral traits. Copyright © 2017 by the Genetics Society of America.

Genetic parameters for reproductive traits in a beef cattle herd ...

African Journals Online (AJOL)

Unknown

Keywords: beef cattle, breeding, genetics, heritability, reproduction .... nature of the female reproductive traits or to the large influence of unidentified environmental effects on ..... Factors affecting some performance traits in Friesian cattle.

The Natural History and Risk Factors of Musculoskeletal Conditions Resulting in Disability Among US Army Personnel

National Research Council Canada - National Science Library

Lincoln, Andrew

2002-01-01

We describe the natural history of 13 musculoskeletal conditions requiring hospitalization and identify demographic, behavioral, psychosocial, occupational, and clinical characteristics most strongly...

Cognitive dysfunction and anxious-impulsive personality traits are endophenotypes for drug dependence.

Science.gov (United States)

Ersche, Karen D; Turton, Abigail J; Chamberlain, Samuel R; Müller, Ulrich; Bullmore, Edward T; Robbins, Trevor W

2012-09-01

Not everyone who takes drugs becomes addicted, but the likelihood of developing drug addiction is greater in people with a family history of drug or alcohol dependence. Relatively little is known about how genetic risk mediates the development of drug dependence. By comparing the phenotypic profile of individuals with and without a family history of addiction, the authors sought to clarify the extent to which cognitive dysfunction and personality traits are shared by family members--and therefore likely to have predated drug dependence--and which aspects are specific to drug-dependent individuals. The authors assessed cognitive function and personality traits associated with drug dependence in stimulant-dependent individuals (N=50), their biological siblings without a history of drug dependence (N=50), and unrelated healthy volunteers (N=50). Cognitive function was significantly impaired in the stimulant-dependent individuals across a range of domains. Deficits in executive function and response control were identified in both the stimulant-dependent individuals and in their non-drug-dependent siblings. Drug-dependent individuals and their siblings also exhibited elevated anxious-impulsive personality traits relative to healthy comparison volunteers. Deficits in executive function and response regulation as well as anxious-impulsive personality traits may represent endophenotypes associated with the risk of developing cocaine or amphetamine dependence. The identification of addiction endophenotypes may be useful in facilitating the rational development of therapeutic and preventive strategies.

Achievement Is a Relation, Not a Trait: The Gravity of the Situation

Science.gov (United States)

Corrado, Gail

2012-01-01

Ability and achievement are not traits: they are relations. Mistaking traits for relations has a history even in science (our understanding of gravity). This mistake is possibly responsible for the lackluster performance of the results of our educational research when we have tried to use it to inform policy. It is particularly troublesome for…

Hyperactivity: nature of the syndrome and its natural history.

Science.gov (United States)

Aman, M G

1984-03-01

The composition of hyperactivity as a syndrome is discussed from a historical perspective, and the principal events leading to the recent emphasis on attentional characteristics of hyperactive children are summarized. Some of the major challenges to the legitimacy of hyperactivity as a valid syndrome are set forth, and after critical examination of the most influential work, it is concluded that hyperactivity has not been disproved. This is followed by a survey of the large follow-up literature dealing with the natural history of children diagnosed as hyperactive. It is noted that the manifestations of the syndrome appear to change with age but there is little indication that problems simply remit with maturity. The evidence indicates that hyperactivity, as diagnosed in the past, is often a serious disorder with long-term and far-reaching consequences for the children and their families. Multivariate studies are also discussed, as they have important implications for differential outcome. Different symptoms such as aggression, overactivity, and learning disability appear to contain unique information about current and future status, and therefore it appears useful to retain these distinctions rather than view such children as part of an undifferentiated group. It is unknown whether the recent guidelines for diagnosing Attention Deficit Disorder with Hyperactivity will alter or refine the outlook for children so identified, but this is an active area of research at present.

Clergymen abiding in the fields: the making of the naturalist observer in eighteenth-century Norwegian natural history.

Science.gov (United States)

Brenna, Brita

2011-06-01

By the mid-eighteenth century, governors of the major European states promoted the study of nature as part of natural-resource based schemes for improvement and economic self-sufficiency. Procuring beneficial knowledge about nature, however, required observers, collectors, and compilers who could produce usable and useful descriptions of nature. The ways governments promoted scientific explorations varied according to the form of government, the makeup of the civil society, the state's economic ideologies and practices, and the geographical situation. This article argues that the roots of a major natural history initiative in Denmark-Norway were firmly planted in the state-church organization. Through the clergymen and their activities, a bishop, supported by the government in Copenhagen, could gather an impressive collection of natural objects, receive observations and descriptions of natural phenomena, and produce natural historical publications that described for the first time many of the species of the north. Devout naturalists were a common species in the eighteenth century, when clergymen and missionaries involved themselves in the investigation of nature in Europe and far beyond. The specific interest here is in how natural history was supported and enforced as part of clerical practice, how specimen exchange was grafted on to pre-existing institutions of gift exchange, and how this influenced the character of the knowledge produced.

Eco-genetic modeling of contemporary life-history evolution.

Science.gov (United States)

Dunlop, Erin S; Heino, Mikko; Dieckmann, Ulf

2009-10-01

We present eco-genetic modeling as a flexible tool for exploring the course and rates of multi-trait life-history evolution in natural populations. We build on existing modeling approaches by combining features that facilitate studying the ecological and evolutionary dynamics of realistically structured populations. In particular, the joint consideration of age and size structure enables the analysis of phenotypically plastic populations with more than a single growth trajectory, and ecological feedback is readily included in the form of density dependence and frequency dependence. Stochasticity and life-history trade-offs can also be implemented. Critically, eco-genetic models permit the incorporation of salient genetic detail such as a population's genetic variances and covariances and the corresponding heritabilities, as well as the probabilistic inheritance and phenotypic expression of quantitative traits. These inclusions are crucial for predicting rates of evolutionary change on both contemporary and longer timescales. An eco-genetic model can be tightly coupled with empirical data and therefore may have considerable practical relevance, in terms of generating testable predictions and evaluating alternative management measures. To illustrate the utility of these models, we present as an example an eco-genetic model used to study harvest-induced evolution of multiple traits in Atlantic cod. The predictions of our model (most notably that harvesting induces a genetic reduction in age and size at maturation, an increase or decrease in growth capacity depending on the minimum-length limit, and an increase in reproductive investment) are corroborated by patterns observed in wild populations. The predicted genetic changes occur together with plastic changes that could phenotypically mask the former. Importantly, our analysis predicts that evolutionary changes show little signs of reversal following a harvest moratorium. This illustrates how predictions offered by

Trait differences between naturalized and invasive plant species independent of residence time and phylogeny

Science.gov (United States)

Gallagher, R V; Randall, R P; Leishman, M R

2015-01-01

The ability to predict which alien plants will transition from naturalized to invasive prior to their introduction to novel regions is a key goal for conservation and has the potential to increase the efficacy of weed risk assessment (WRA). However, multiple factors contribute to plant invasion success (e.g., functional traits, range characteristics, residence time, phylogeny), and they all must be taken into account simultaneously in order to identify meaningful correlates of invasion success. We compiled 146 pairs of phylogenetically paired (congeneric) naturalized and invasive plant species in Australia with similar minimum residence times (i.e., time since introduction in years). These pairs were used to test for differences in 5 functional traits (flowering duration, leaf size, maximum height, specific leaf area [SLA], seed mass) and 3 characteristics of species’ native ranges (biome occupancy, mean annual temperature, and rainfall breadth) between naturalized and invasive species. Invasive species, on average, had larger SLA, longer flowering periods, and were taller than their congeneric naturalized relatives. Invaders also exhibited greater tolerance for different environmental conditions in the native range, where they occupied more biomes and a wider breadth of rainfall and temperature conditions than naturalized congeners. However, neither seed mass nor leaf size differed between pairs of naturalized and invasive species. A key finding was the role of SLA in distinguishing between naturalized and invasive pairs. Species with high SLA values were typically associated with faster growth rates, more rapid turnover of leaf material, and shorter lifespans than those species with low SLA. This suite of characteristics may contribute to the ability of a species to transition from naturalized to invasive across a wide range of environmental contexts and disturbance regimes. Our findings will help in the refinement of WRA protocols, and we advocate the

Disparate relatives: Life histories vary more in genera occupying intermediate environments

Czech Academy of Sciences Publication Activity Database

Hermant, M.; Hennion, F.; Bartish, Igor V.; Yugel, B.; Prinzing, A.

2012-01-01

Roč. 14, č. 4 (2012), s. 283-301 ISSN 1433-8319 Institutional support: RVO:67985939 Keywords : life-history traits * dated phylogeny * regional trait variability Subject RIV: EF - Botanics Impact factor: 4.158, year: 2012

Exploiting natural variation in Arabidopsis

NARCIS (Netherlands)

Molenaar, J.A.; Keurentjes, J.J.B.; Sanchez-Serrano, J.J.; Salinas, J.

2014-01-01

Natural variation for many traits is present within the species Arabidopsis thaliana. This chapter describes the use of natural variation to elucidate genes underlying the regulation of quantitative traits. It deals with the development and use of mapping populations, the detection and handling of

Natural history of minimal anterior displacements of the temporomandibular joint meniscus

International Nuclear Information System (INIS)

Drace, J.E.

1988-01-01

Magnetic resonance (MR) imaging of the temporomandibular joint (TMJ) often provides more precise localization of the meniscus than other imaging modalities. Previous study of the distribution of meniscus position in a control population showed that anterior displacements of more than 10 0 were more than 2 standard deviations from the mean, but the clinical significance and natural history of minimal displacements remained uncertain. Twenty follow-up MR studies were performed after 1-2 years in subjects with minimal meniscus displacements drawn from an original series of 125 symptomatic patients and 50 asymptomatic volunteers. These were correlated with repeated clinical histories and clinical examinations. A significant increase in the amount of anterior displacement was found in 55% of the originally asymptomatic volunteers with minimal displacements, which was accompanied by new symptoms in 40%. This was seen exclusively among those with a history of orthodontia. Worsening anterior displacements were seen in 50% of the patient population, and 25% had associated worsening symptoms. These findings indicate that detection of even minimal displacements of the TMJ meniscus is necessary and warrants follow-up MR examinations. Routine follow-up MR images should be obtained following malocclusion treatment and after major dental procedures

The biology and natural history of prostate cancer: a short introduction.

Science.gov (United States)

Holmberg, Lars; Van Hemelrijck, Mieke

2014-01-01

This chapter aims to serve as a quick glance outlining an overall picture of mainstream thoughts, and to serve as a point of departure for more thorough discussions. The introduction of PSA testing has immensely complicated research in prostate cancer epidemiology and biology and added new clinical and biological domains. As for many cancers, age and ethnic origin are the strongest known risk factors. While migrant studies imply that environment and/or personal life style is important, epidemiological studies have failed to establish any strong leads. Despite the known androgen dependence of prostate cancer, there is little to support that circulating levels of androgens, estrogens or 5-alpha-reductase are associated with risk of developing the disease. However, a consistent finding is a positive association with levels of Insulin-like Growth Factor-1 (IGF-1). Prostate cancer is one of the cancers most strongly related to inherited susceptibility, even when taking into account that family history of prostate cancer triggers PSA testing among relatives. A number of somatic genetic alterations (amplifications, deletions, point mutations, translocations) are associated with prostate cancer risk. Findings for alterations in FASN, HPN, AMACR and MYC have been fairly consistent. Recent research shows that the notion of "hormone-independent prostate cancer" has to be revised: most prostate cancers remain dependent on androgen receptor signalling also after progression despite traditional androgen deprivation therapy. Traditional markers of stage and type of disease still play a major role for prognostication and treatment decisions. Prostate cancer is one of the few cancers where patients have been recommended watchful waiting or active surveillance. This provides opportunities for studies of natural history of the disease. The understanding of prostate cancer aetiology and natural history has progressed slowly. However, the current situation is positively challenging and

The natural history of Leydig cell testicular tumours: an analysis of the National Cancer Registry.

Science.gov (United States)

Nason, G J; Redmond, E J; Considine, S W; Omer, S I; Power, D; Sweeney, P

2018-05-01

Leydig cell tumour (LCT) of the testis is a rare histological subtype of stromal tumours, accounting for 1 to 3% of testicular neoplasms. The natural history of LCT is poorly understood. The aim of this study was to assess the incidence and natural history of Leydig cell tumours (LCT) of the testes. A search of the National Cancer Registry of Ireland database was performed regarding Leydig cell testicular tumours. Recurrence free survival (RFS) and disease-specific survival (DSS) were analysed. Between 1994 and 2013, 2755 new cases of testicular cancer were diagnosed in Ireland. Of these, 22 (0.79%) were Leydig cell tumours. Nineteen were invasive (stage T1) and three were in situ (stage Tis). One patient developed a local recurrence following an organ preserving procedure and underwent a completion orchidectomy 107 days after initial diagnosis. No further treatment was required. There have been no disease-specific deaths. The 1-, 3- and 5-year overall survival (OS) rates were 95.5, 88.2 and 73.3%, respectively. The 5-year disease-specific survival (DSS) was 100% and the 5-year recurrence free survival (RFS) was 93.3%. From the National Cancer Registry, LCT has been shown to be a rare subtype of testicular tumour. Due to the relatively favourable natural history, it may be possible to tailor less aggressive surveillance regimens in these patients.

Azadirachtin-induced effects on various life history traits and cellular immune reactions of Galleria mellonella (Lepidoptera: Pyralidae

Directory of Open Access Journals (Sweden)

Er Aylin

2017-01-01

Full Text Available The effects of the botanical insecticide azadirachtin were examined on the life history traits, fecundity and immune parameters of Galleria mellonella L. (Lepidoptera: Pyralidae. We determined that for the topical application of azadirachtin, the LC50 was 16.564 ppm; at 100 ppm the adult emergence time was prolonged, however the longevity of adults remained unchanged above sublethal concentrations. The mean number of healthy eggs and the fecundity of adults decreased, whereas the number of defective eggs increased with azadirachtin treatment. At concentrations >50 ppm female G. mellonella adults laid no eggs. Azadirachtin reduced total hemocyte counts at 24 and 48 h posttreatment, however the alterations in differential hemocyte counts were only significant at 100 ppm. Laminarin-induced nodulation response and the spreading ability of hemocytes were also suppressed with azadirachtin treatment. Our results suggest that azadirachtin, as a good candidate for integrated pest control, has the capability to affect the biological parameters and cellular immunity of the model insect G. mellonella.

Comparative Analyses of Phenotypic Trait Covariation within and among Populations.

Science.gov (United States)

Peiman, Kathryn S; Robinson, Beren W

2017-10-01

Many morphological, behavioral, physiological, and life-history traits covary across the biological scales of individuals, populations, and species. However, the processes that cause traits to covary also change over these scales, challenging our ability to use patterns of trait covariance to infer process. Trait relationships are also widely assumed to have generic functional relationships with similar evolutionary potentials, and even though many different trait relationships are now identified, there is little appreciation that these may influence trait covariation and evolution in unique ways. We use a trait-performance-fitness framework to classify and organize trait relationships into three general classes, address which ones more likely generate trait covariation among individuals in a population, and review how selection shapes phenotypic covariation. We generate predictions about how trait covariance changes within and among populations as a result of trait relationships and in response to selection and consider how these can be tested with comparative data. Careful comparisons of covariation patterns can narrow the set of hypothesized processes that cause trait covariation when the form of the trait relationship and how it responds to selection yield clear predictions about patterns of trait covariation. We discuss the opportunities and limitations of comparative approaches to evaluate hypotheses about the evolutionary causes and consequences of trait covariation and highlight the importance of evaluating patterns within populations replicated in the same and in different selective environments. Explicit hypotheses about trait relationships are key to generating effective predictions about phenotype and its evolution using covariance data.

The whip spider collection (Arachnida, Amblypygi held in the Natural History Museum Vienna, Austria

Directory of Open Access Journals (Sweden)

Seiter, Michael

2013-11-01

Full Text Available We present data and remarks on the history and contents of the whip spider collection housed in the Natural History Museum of Vienna, Austria. The collection comprises a total of 167 specimens from 4 families, 10 genera and 27 species. It includes types of four species: Charinus ioanniticus (Kritscher, 1959, Damon brachialis Weygoldt, 1999, Phrynus parvulus (Pocock, 1902 and Paraphrynus mexicanus (Bilimek, 1867. Short notes on interesting objects and former curators are provided as well as an appendix with a list of species kept alive by Michael Seiter.

Shrub-Steppe Seasons A Natural History of the Mid-Columbia Basin

Energy Technology Data Exchange (ETDEWEB)

LE Rogers

1995-08-01

This book collects and updates a series of articles about the natural history of the Mid-Columbia region. The articles first appeared as a monthly column titled ''Natural History'' in the Tri-City Herald, beginning in May 1991. My approach has been to condense the best of what is known about the ecology of the region to a manageable length with little in the way of technical language and terms. Admittedly, there is a bias toward those topics and species on which I have either been personally involved or observed as part of the ecology research programs conducted on the Fitzner/Eberhardt Arid Lands Ecology (ALE) Reserve. The ALE Reserve is situated on the northeast-facing flank of the Rattlesnake Hills. Rattlesnake Mountain with a crest of over 3,600 feet is visible throughout much of the Mid-Columbia. Shrub-steppe grasslands once covered a large part of the western United States but most have been converted to other uses. The ALE site is the only remaining sizeable acreage (120 square miles) that is in near pristine condition and provides the only clear indication as to what the early trappers, traders, pioneers, and tribal members may have encountered in their day-to-day activities. In this respect, ALE provides a visible touchstone linking the past with the present for all of us.

History and Nature of Science in High School: Building up Parameters to Guide Educational Materials and Strategies

Science.gov (United States)

Forato, Thais Cyrino de Mello; Martins, Roberto de Andrade; Pietrocola, Mauricio

2012-01-01

This article presents the main results of a research examining the didactic transposition of history and philosophy of science in high school level. The adaptation of history of science to this particular level, addressing some aspects of the nature of science aiming at the students' critical engagement, was analyzed by examining both the…

Massive plexiform neurofibromas in childhood: natural history and management issues.

Science.gov (United States)

Serletis, Demitre; Parkin, Patricia; Bouffet, Eric; Shroff, Manohar; Drake, James M; Rutka, James T

2007-05-01

The authors review their experience with massive plexiform neurofibromas (PNs) in patients with pediatric neurofibromatosis Type 1 (NF1) to better characterize the natural history and management of these complex lesions. The authors performed a retrospective review of data obtained in seven patients with NF1 in whom massive PNs were diagnosed at The Hospital for Sick Children in Toronto, Ontario, Canada. These patients attended routine follow-up examinations conducted by a number of specialists, and serial neuroimaging studies were obtained to monitor disease progression. The most common presenting feature of PN was that of a painful, expanding lesion. Furthermore, two patients harbored multiple, distinct PNs affecting different body sites. With respect to management, two patients were simply observed, undergoing serial neuroimaging studies; two patients underwent biopsy sampling of their plexiform lesions; two patients underwent attempted medical treatment (farnesyl transferase inhibitor, R11577, and cyclophosphamide chemotherapy); and three patients required surgical debulking of their PNs because the massive growth of these tumors caused functional compromise. Ultimately, one patient died of respiratory complications due to progressive growth of the massive PN lesion. In this review of their experience, the authors found certain features that underscore the presentation and natural history of PNs. The management of these complex lesions, however, remains unclear. Slow-growing PNs may be observed conservatively, but the authors' experience suggests that resection should be considered in selected cases involving significant deterioration or functional compromise. Nevertheless, patients with massive PNs will benefit from close surveillance by a team of specialists to monitor for ongoing disease progression.

Plant functional traits in relation to fire in crown-fire ecosystems

Science.gov (United States)

Pausas, Juli G.; Bradstock, Ross A.; Keith, David A.; Keeley, Jon E.

2004-01-01

Disturbance is a dominant factor in many ecosystems, and the disturbance regime is likely to change over the next decades in response to land-use changes and global warming. We assume that predictions of vegetation dynamics can be made on the basis of a set of life-history traits that characterize the response of a species to disturbance. For crown-fire ecosystems, the main plant traits related to postfire persistence are the ability to resprout (persistence of individuals) and the ability to retain a persistent seed bank (persistence of populations). In this context, we asked (1) to what extent do different life-history traits co-occur with the ability to resprout and/or the ability to retain a persistent seed bank among differing ecosystems and (2) to what extent do combinations of fire-related traits (fire syndromes) change in a fire regime gradient? We explored these questions by reviewing the literature and analyzing databases compiled from different crown-fire ecosystems (mainly eastern Australia, California, and the Mediterranean basin). The review suggests that the pattern of correlation between the two basic postfire persistent traits and other plant traits varies between continents and ecosystems. From these results we predict, for instance, that not all resprouters respond in a similar way everywhere because the associated plant traits of resprouter species vary in different places. Thus, attempts to generalize predictions on the basis of the resprouting capacity may have limited power at a global scale. An example is presented for Australian heathlands. Considering the combination of persistence at individual (resprouting) and at population (seed bank) level, the predictive power at local scale was significantly increased.

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

DEFF Research Database (Denmark)

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

2012-01-01

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

Population genetic structure of the endemic rosewoods Dalbergia cochinchinensis and D. oliveri at a regional scale reflects the Indochinese landscape and life-history traits

DEFF Research Database (Denmark)

Hartvig, Ida; So, Thea; Changtragoon, Suchitra

2018-01-01

of the distribution area, particularly in Cambodia. We suggest that this pattern is ancient, reflecting the demographic history of the species and possible location of refugia during earlier time periods with limited forest cover, which was supported by signs of old genetic bottlenecks. The D. oliveri populations had......Indochina is a biodiversity hot spot and harbors a high number of endemic species, most of which are poorly studied. This study explores the genetic structure and reproductive system of the threatened endemic timber species Dalbergia cochinchinensis and Dalbergia oliveri using microsatellite data...... from populations across Indochina and relates it to landscape characteristics and life-history traits. We found that the major water bodies in the region, Mekong and Tonle Sap, represented barriers to gene flow and that higher levels of genetic diversity were found in populations in the center...

Robust Trapdoor Tarantula Haploclastus validus Pocock, 1899: notes on taxonomy, distribution and natural history (Araneae: Theraphosidae: Thrigmopoeinae

Directory of Open Access Journals (Sweden)

Z.A. Mirza

2011-10-01

Full Text Available The genus Haploclastus is endemic to India and is represented by six species. One of the species H. validus Pocock, 1899 was described from Matheran and has remained poorly known in terms of its natural history and distribution. During recent surveys the species was for the first time found again since its description nearly 110 years ago. Based on the new material collected it is redescribed and data on its natural history and distribution are added. It is the first record of an Indian theraphosid spider, which closes its burrow with a trapdoor.

Development of a Lifespan-Based Novel Composite Person-Reported Outcome Measure Using Data from the CINRG Duchenne Natural History Study

Science.gov (United States)

2017-10-01

Duchenne natural history study PRINCIPAL INVESTIGATOR: McDonald, Craig M. CONTRACTING ORGANIZATION: University of California, Davis Davis, CA 95618...composite person- reported outcome measure using data from the CINRG Duchenne natural history study 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Craig...SUPPLEMENTARY NOTES 14. ABSTRACT Development of novel technologies and therapeutic agents to treat Duchenne muscular dystrophy (DMD) have increased

Deciphering the adjustment between environment and life history in annuals: lessons from a geographically-explicit approach in Arabidopsis thaliana.

Science.gov (United States)

Manzano-Piedras, Esperanza; Marcer, Arnald; Alonso-Blanco, Carlos; Picó, F Xavier

2014-01-01

The role that different life-history traits may have in the process of adaptation caused by divergent selection can be assessed by using extensive collections of geographically-explicit populations. This is because adaptive phenotypic variation shifts gradually across space as a result of the geographic patterns of variation in environmental selective pressures. Hence, large-scale experiments are needed to identify relevant adaptive life-history traits as well as their relationships with putative selective agents. We conducted a field experiment with 279 geo-referenced accessions of the annual plant Arabidopsis thaliana collected across a native region of its distribution range, the Iberian Peninsula. We quantified variation in life-history traits throughout the entire life cycle. We built a geographic information system to generate an environmental data set encompassing climate, vegetation and soil data. We analysed the spatial autocorrelation patterns of environmental variables and life-history traits, as well as the relationship between environmental and phenotypic data. Almost all environmental variables were significantly spatially autocorrelated. By contrast, only two life-history traits, seed weight and flowering time, exhibited significant spatial autocorrelation. Flowering time, and to a lower extent seed weight, were the life-history traits with the highest significant correlation coefficients with environmental factors, in particular with annual mean temperature. In general, individual fitness was higher for accessions with more vigorous seed germination, higher recruitment and later flowering times. Variation in flowering time mediated by temperature appears to be the main life-history trait by which A. thaliana adjusts its life history to the varying Iberian environmental conditions. The use of extensive geographically-explicit data sets obtained from field experiments represents a powerful approach to unravel adaptive patterns of variation. In a

The life-history of a springtail Folsomia candida living in soil contaminated with nonylphenol

DEFF Research Database (Denmark)

Widarto, T. H.; Krogh, P. H.; Forbes, V.

Nonylphenol (NP) has been known for long time as a suspected endocrine disruptor in animals. We have conducted an experiment to look at the effect of NP on the life-history of the parthenogenetic springtail, Folsomia candida. Six sub-lethal concentrations (0, 8,16, 24, 32, 40 mg/kg dry soil......) were applied to 6 replicates of soil containing an individual of 0-1 day old juvenile. During continuous exposure (63 days), we assessed springtail life-history traits such as: survival, growth rate, molting time, time between molting, time to first reproduction, egg production, and viability...... population growth rate (l). Decomposition analysis to investigate the contribution of each of the affected life-history traits to the effects observed on l, and elasticity analysis to examine the relative sensitivity of l to changes in each of the life history traits provided valuable insight...

Sustaining diversity in trait-based models of phytoplankton communities

Directory of Open Access Journals (Sweden)

Agostino eMerico

2014-10-01

Full Text Available It is well-established that when equilibrium is attained for two species competing for the same limiting resource in a stable, uniform environment, one species will eliminate the other due to competitive exclusion. While competitive exclusion is observed in laboratory experiments and ecological models, the phenomenon seems less common in nature, where static equilibrium is prevented by the fluctuating physical environment and by other factors that constantly change species abundances and the nature of competitive interactions. Trait-based models of phytoplankton communities appear to be useful tools for describing the evolution of large assemblages of species with aggregate group properties such as total biomass, mean trait, and trait variance, the latter representing the functional diversity of the community. Such an approach, however, is limited by the tendency of the trait variance to unrealistically decline to zero over time. This tendency to lose diversity, and therefore adaptive capacity, is typically solved by fixing the variance or by considering exogenous processes such as immigration. Exogenous processes, however, cannot explain the maintenance of adaptive capacity often observed in the closed environment of chemostat experiments. Here we present a new method to sustain diversity in adaptive trait-based models of phytoplankton communities based on a mechanism of trait diffusion through subsequent generations. Our modeling approach can therefore account for endogenous processes such as rapid evolution or transgenerational trait plasticity.

Middle Level Preservice Teachers Experience a Natural History Arts-Integrated Interdisciplinary Thematic Unit

Science.gov (United States)

Weber, Carolyn A.; Rule, Audrey C.

2017-01-01

Curricular demands and best practices for middle school require interdisciplinary units. Arts integration can provide motivation and a new pathway to learning. This unit focused on inquiry into the natural history of artifacts and rocks recovered from the exposed subsoil of an area near Cedar Falls, Iowa that had been bulldozed as part of…

[Conservation and natural history around 1900: the contribution of the Sarasin cousins].

Science.gov (United States)

Simon, Christian

2014-01-01

Some basic concepts for the creation of the Swiss National Park were derived from observations made in Sri Lanka, Indonesia and New Caledonia. European researchers feared that the study of "virgin nature" would no longer be possible, as various species would soon become extinct under the combined influences of colonial practices and profit-oriented capitalism. While the motives for protecting nature originated from experiences made in the southern hemisphere, their scientific concept of conservation was based on European natural history and the related theories of evolution. In the light of this approach, endangered zoological and botanical species as well as "primitive" varieties of man were appreciated as "documents" to be preserved within their original environment for future scientific reference and research. Museum collections and reservations (parks) were two types of repositories connected to each other by the same objective.

Urbanization and fertility: an event-history analysis of coastal Ghana.

Science.gov (United States)

White, Michael J; Muhidin, Salut; Andrzejewski, Catherine; Tagoe, Eva; Knight, Rodney; Reed, Holly

2008-11-01

In this article, we undertake an event-history analysis of fertility in Ghana. We exploit detailed life history calendar data to conduct a more refined and definitive analysis of the relationship among personal traits, urban residence, and fertility. Although urbanization is generally associated with lower fertility in developing countries, inferences in most studies have been hampered by a lack of information about the timing of residence in relationship to childbearing. We find that the effect of urbanization itself is strong, evident, and complex, and persists after we control for the effects of age, cohort, union status, and education. Our discrete-time event-history analysis shows that urban women exhibit fertility rates that are, on average, 11% lower than those of rural women, but the effects vary by parity. Differences in urban population traits would augment the effects of urban adaptation itself Extensions of the analysis point to the operation of a selection effect in rural-to-urban mobility but provide limited evidence for disruption effects. The possibility of further selection of urbanward migrants on unmeasured traits remains. The analysis also demonstrates the utility of an annual life history calendar for collecting such data in the field.

ATLANTIC MAMMAL TRAITS: a data set of morphological traits of mammals in the Atlantic Forest of South America.

Science.gov (United States)

Gonçalves, Fernando; Bovendorp, Ricardo S; Beca, Gabrielle; Bello, Carolina; Costa-Pereira, Raul; Muylaert, Renata L; Rodarte, Raisa R; Villar, Nacho; Souza, Rafael; Graipel, Maurício E; Cherem, Jorge J; Faria, Deborah; Baumgarten, Julio; Alvarez, Martín R; Vieira, Emerson M; Cáceres, Nilton; Pardini, Renata; Leite, Yuri L R; Costa, Leonora P; Mello, Marco A R; Fischer, Erich; Passos, Fernando C; Varzinczak, Luiz H; Prevedello, Jayme A; Cruz-Neto, Ariovaldo P; Carvalho, Fernando; Percequillo, Alexandre R; Paviolo, Agustin; Nava, Alessandra; Duarte, José M B; de la Sancha, Noé U; Bernard, Enrico; Morato, Ronaldo G; Ribeiro, Juliana F; Becker, Rafael G; Paise, Gabriela; Tomasi, Paulo S; Vélez-Garcia, Felipe; Melo, Geruza L; Sponchiado, Jonas; Cerezer, Felipe; Barros, Marília A S; de Souza, Albérico Q S; Dos Santos, Cinthya C; Giné, Gastón A F; Kerches-Rogeri, Patricia; Weber, Marcelo M; Ambar, Guilherme; Cabrera-Martinez, Lucía V; Eriksson, Alan; Silveira, Maurício; Santos, Carolina F; Alves, Lucas; Barbier, Eder; Rezende, Gabriela C; Garbino, Guilherme S T; Rios, Élson O; Silva, Adna; Nascimento, Alexandre Túlio A; de Carvalho, Rodrigo S; Feijó, Anderson; Arrabal, Juan; Agostini, Ilaria; Lamattina, Daniela; Costa, Sebastian; Vanderhoeven, Ezequiel; de Melo, Fabiano R; de Oliveira Laroque, Plautino; Jerusalinsky, Leandro; Valença-Montenegro, Mônica M; Martins, Amely B; Ludwig, Gabriela; de Azevedo, Renata B; Anzóategui, Agustin; da Silva, Marina X; Figuerêdo Duarte Moraes, Marcela; Vogliotti, Alexandre; Gatti, Andressa; Püttker, Thomas; Barros, Camila S; Martins, Thais K; Keuroghlian, Alexine; Eaton, Donald P; Neves, Carolina L; Nardi, Marcelo S; Braga, Caryne; Gonçalves, Pablo R; Srbek-Araujo, Ana Carolina; Mendes, Poliana; de Oliveira, João A; Soares, Fábio A M; Rocha, Patrício A; Crawshaw, Peter; Ribeiro, Milton C; Galetti, Mauro

2018-02-01

Measures of traits are the basis of functional biological diversity. Numerous works consider mean species-level measures of traits while ignoring individual variance within species. However, there is a large amount of variation within species and it is increasingly apparent that it is important to consider trait variation not only between species, but also within species. Mammals are an interesting group for investigating trait-based approaches because they play diverse and important ecological functions (e.g., pollination, seed dispersal, predation, grazing) that are correlated with functional traits. Here we compile a data set comprising morphological and life history information of 279 mammal species from 39,850 individuals of 388 populations ranging from -5.83 to -29.75 decimal degrees of latitude and -34.82 to -56.73 decimal degrees of longitude in the Atlantic forest of South America. We present trait information from 16,840 individuals of 181 species of non-volant mammals (Rodentia, Didelphimorphia, Carnivora, Primates, Cingulata, Artiodactyla, Pilosa, Lagomorpha, Perissodactyla) and from 23,010 individuals of 98 species of volant mammals (Chiroptera). The traits reported include body mass, age, sex, reproductive stage, as well as the geographic coordinates of sampling for all taxa. Moreover, we gathered information on forearm length for bats and body length and tail length for rodents and marsupials. No copyright restrictions are associated with the use of this data set. Please cite this data paper when the data are used in publications. We also request that researchers and teachers inform us of how they are using the data. © 2018 by the Ecological Society of America.

The association between parental life history and offspring phenotype in Atlantic salmon.

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Van Leeuwen, Travis E; McLennan, Darryl; McKelvey, Simon; Stewart, David C; Adams, Colin E; Metcalfe, Neil B

2016-02-01

In many taxa there is considerable intraspecific variation in life history strategies from within a single population, reflecting alternative routes through which organisms can achieve successful reproduction. Atlantic salmon Salmo salar (Linnaeus) show some of the greatest within-population variability in life history strategies amongst vertebrates, with multiple discrete male and female life histories co-existing and interbreeding on many spawning grounds, although the effect of the various combinations of life histories on offspring traits remains unknown. Using crosses of wild fish we show here that the life history strategy of both parents was significantly associated with a range of offspring traits. Mothers that had spent longer at sea (2 versus 1 year) produced offspring that were heavier, longer and in better condition at the time of first feeding. However, these relationships disappeared shortly after fry had begun feeding exogenously. At this stage, the juvenile rearing environment (i.e. time spent in fresh water as juveniles) of the mother was a better predictor of offspring traits, with mothers that were faster to develop in fresh water (migrating to sea after two rather than three years of age) producing offspring that had higher maximal metabolic rates, aerobic scopes, and that grew faster. Faster developing fathers (1 year old sneaker males) tended to produce offspring that had higher maximal metabolic rates, were in better body condition and grew faster. The results suggest that both genetic effects and those related to parental early and late life history contribute to offspring traits. © 2016. Published by The Company of Biologists Ltd.

The natural history of adolescent idiopathic scoliosis

Directory of Open Access Journals (Sweden)

Wong Hee-Kit

2010-01-01

Full Text Available There have been great advances in the conservative and surgical treatment for adolescent idiopathic scoliosis in the last few decades. The challenge for the physician is the decision for the optimal time to institute therapy for the individual child. This makes an understanding of the natural history and risk factors for curve progression of significant importance. Reported rates of curve progression vary from 1.6% for skeletally mature children with a small curve magnitude to 68% for skeletally immature children with larger curve magnitudes. Although the patient′s age at presentation, the Risser sign, the patient′s menarchal status and the magnitude of the curve have been described as risk factors for curve progression, there is evidence that the absolute curve magnitude at presentation may be most predictive of progression in the long term. A curve magnitude of 25º at presentation may be predictive of a greater risk of curve progression. Advances in research may unlock novel predictive factors, which are based on the underlying pathogenesis of this disorder.

Locus-specific view of flax domestication history

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Fu, Yong-Bi; Diederichsen, Axel; Allaby, Robin G

2012-01-01

Crop domestication has been inferred genetically from neutral markers and increasingly from specific domestication-associated loci. However, some crops are utilized for multiple purposes that may or may not be reflected in a single domestication-associated locus. One such example is cultivated flax (Linum usitatissimum L.), the earliest oil and fiber crop, for which domestication history remains poorly understood. Oil composition of cultivated flax and pale flax (L. bienne Mill.) indicates that the sad2 locus is a candidate domestication locus associated with increased unsaturated fatty acid production in cultivated flax. A phylogenetic analysis of the sad2 locus in 43 pale and 70 cultivated flax accessions established a complex domestication history for flax that has not been observed previously. The analysis supports an early, independent domestication of a primitive flax lineage, in which the loss of seed dispersal through capsular indehiscence was not established, but increased oil content was likely occurred. A subsequent flax domestication process occurred that probably involved multiple domestications and includes lineages that contain oil, fiber, and winter varieties. In agreement with previous studies, oil rather than fiber varieties occupy basal phylogenetic positions. The data support multiple paths of flax domestication for oil-associated traits before selection of the other domestication-associated traits of seed dispersal loss and fiber production. The sad2 locus is less revealing about the origin of winter tolerance. In this case, a single domestication-associated locus is informative about the history of domesticated forms with the associated trait while partially informative on forms less associated with the trait. PMID:22408732

Post-Mastectomy and Phantom Breast Pain: Risk Factors, Natural History, and Impact on Quality of Life

National Research Council Canada - National Science Library

Dworkin, Robert

2003-01-01

.... The primary aims of this research were to identify risk factors for these chronic pain syndromes following surgical procedures for breast cancer, characterize their natural history, and examine...

The role of life histories and trophic interactions in population recovery.

Science.gov (United States)

Audzijonyte, Asta; Kuparinen, Anna

2016-08-01

Factors affecting population recovery from depletion are at the focus of wildlife management. Particularly, it has been debated how life-history characteristics might affect population recovery ability and productivity. Many exploited fish stocks have shown temporal changes towards earlier maturation and reduced adult body size, potentially owing to evolutionary responses to fishing. Whereas such life-history changes have been widely documented, their potential role on stock's ability to recover from exploitation often remains ignored by traditional fisheries management. We used a marine ecosystem model parameterized for Southeastern Australian ecosystem to explore how changes towards "faster" life histories might affect population per capita growth rate r. We show that for most species changes towards earlier maturation during fishing have a negative effect (3-40% decrease) on r during the recovery phase. Faster juvenile growth and earlier maturation were beneficial early in life, but smaller adult body sizes reduced the lifetime reproductive output and increased adult natural mortality. However, both at intra- and inter-specific level natural mortality and trophic position of the species were as important in determining r as species longevity and age of maturation, suggesting that r cannot be predicted from life-history traits alone. Our study highlights that factors affecting population recovery ability and productivity should be explored in a multi-species context, where both age-specific fecundity and survival schedules are addressed simultaneously. It also suggests that contemporary life-history changes in harvested species are unlikely to increase their resilience and recovery ability. © 2016 Society for Conservation Biology.

Composition and natural history notes of the coastal snake assemblage from Northern Bahia, Brazil

Science.gov (United States)

Marques, Ricardo; Mebert, Konrad; Fonseca, Érica; Rödder, Dennis; Solé, Mirco; Tinôco, Moacir Santos

2016-01-01

Abstract Information about the snake diversity and their natural history from the Atlantic forest domain in Brazil refer mostly to inland forests than to coastal region. Within the state of Bahia, this knowledge is concentrated to the southeastern coastal stretch. Herein we report on the diversity of snakes from the restinga, ombrophilous forest and anthropogenic environment from the northern Atlantic coast of Bahia. We sampled nine sites for three years and visited four museum collections. Furthermore, we provide anecdotal natural history information, voucher analyses, literature complements, and a key to fascilitate species identification. We report a total of 774 snakes belonging to 50 species and 23 new distribution records for northeastern coast of Bahia, supplemented by new data on feeding and reproduction. The number of detected species is similar to numbers obtained in comparable studies from other Brazilian ecoregions. This study reports and focuses for the first time on all known species of snakes from the northeastern coast of Bahia. PMID:27594800

Composition and natural history notes of the coastal snake assemblage from Northern Bahia, Brazil.

Science.gov (United States)

Marques, Ricardo; Mebert, Konrad; Fonseca, Érica; Rödder, Dennis; Solé, Mirco; Tinôco, Moacir Santos

2016-01-01

Information about the snake diversity and their natural history from the Atlantic forest domain in Brazil refer mostly to inland forests than to coastal region. Within the state of Bahia, this knowledge is concentrated to the southeastern coastal stretch. Herein we report on the diversity of snakes from the restinga, ombrophilous forest and anthropogenic environment from the northern Atlantic coast of Bahia. We sampled nine sites for three years and visited four museum collections. Furthermore, we provide anecdotal natural history information, voucher analyses, literature complements, and a key to fascilitate species identification. We report a total of 774 snakes belonging to 50 species and 23 new distribution records for northeastern coast of Bahia, supplemented by new data on feeding and reproduction. The number of detected species is similar to numbers obtained in comparable studies from other Brazilian ecoregions. This study reports and focuses for the first time on all known species of snakes from the northeastern coast of Bahia.

Reconstructing the Phylogenetic History of Long-Term Effective Population Size and Life-History Traits Using Patterns of Amino Acid Replacement in Mitochondrial Genomes of Mammals and Birds

Science.gov (United States)

Nabholz, Benoit; Lartillot, Nicolas

2013-01-01

The nearly neutral theory, which proposes that most mutations are deleterious or close to neutral, predicts that the ratio of nonsynonymous over synonymous substitution rates (dN/dS), and potentially also the ratio of radical over conservative amino acid replacement rates (Kr/Kc), are negatively correlated with effective population size. Previous empirical tests, using life-history traits (LHT) such as body-size or generation-time as proxies for population size, have been consistent with these predictions. This suggests that large-scale phylogenetic reconstructions of dN/dS or Kr/Kc might reveal interesting macroevolutionary patterns in the variation in effective population size among lineages. In this work, we further develop an integrative probabilistic framework for phylogenetic covariance analysis introduced previously, so as to estimate the correlation patterns between dN/dS, Kr/Kc, and three LHT, in mitochondrial genomes of birds and mammals. Kr/Kc displays stronger and more stable correlations with LHT than does dN/dS, which we interpret as a greater robustness of Kr/Kc, compared with dN/dS, the latter being confounded by the high saturation of the synonymous substitution rate in mitochondrial genomes. The correlation of Kr/Kc with LHT was robust when controlling for the potentially confounding effects of nucleotide compositional variation between taxa. The positive correlation of the mitochondrial Kr/Kc with LHT is compatible with previous reports, and with a nearly neutral interpretation, although alternative explanations are also possible. The Kr/Kc model was finally used for reconstructing life-history evolution in birds and mammals. This analysis suggests a fairly large-bodied ancestor in both groups. In birds, life-history evolution seems to have occurred mainly through size reduction in Neoavian birds, whereas in placental mammals, body mass evolution shows disparate trends across subclades. Altogether, our work represents a further step toward a more

Climatic conditions cause complex patterns of covariation between demographic traits in a long-lived raptor

NARCIS (Netherlands)

Herfindal, Ivar; van de Pol, Martijn; Nielsen, Jan Tøttrup; Sæther, Bernt-Erik; Møller, Anders Pape

2015-01-01

1.Environmental variation can induce life history changes that can last over a large part of the lifetime of an organism. If multiple demographic traits are affected, expected changes in climate may influence environmental covariances among traits in a complex manner. Thus, examining the

Neurolinguistic programming training, trait anxiety, and locus of control.

Science.gov (United States)

Konefal, J; Duncan, R C; Reese, M A

1992-06-01

Training in the neurolinguistic programming techniques of shifting perceptual position, visual-kinesthetic dissociation, timelines, and change-history, all based on experiential cognitive processing of remembered events, leads to an increased awareness of behavioral contingencies and a more sensitive recognition of environmental cues which could serve to lower trait anxiety and increase the sense of internal control. This study reports on within-person and between-group changes in trait anxiety and locus of control as measured on the Spielberger State-Trait Anxiety Inventory and Wallston, Wallston, and DeVallis' Multiple Health Locus of Control immediately following a 21-day residential training in neurolinguistic programming. Significant with-in-person decreases in trait-anxiety scores and increases in internal locus of control scores were observed as predicted. Chance and powerful other locus of control scores were unchanged. Significant differences were noted on trait anxiety and locus of control scores between European and U.S. participants, although change scores were similar for the two groups. These findings are consistent with the hypothesis that this training may lower trait-anxiety scores and increase internal locus of control scores. A matched control group was not available, and follow-up was unfortunately not possible.

Fracture in Duchenne Muscular Dystrophy: Natural History and Vitamin D Deficiency.

Science.gov (United States)

Perera, Nadia; Sampaio, Hugo; Woodhead, Helen; Farrar, Michelle

2016-08-01

The present study examined the natural history of fracture and vitamin D levels in Duchenne muscular dystrophy patients, who are vulnerable to osteoporosis and fractures. Retrospective analysis of a cohort of 48 Duchenne muscular dystrophy patients revealed that 43% of patients experienced ≥1 fracture. Fracture probabilities at ages 6, 9, 12, and 15 years were 4%, 9%, 31%, and 60% respectively, accelerating around the time of ambulation loss (mean age 11.8 ± 2.7 years). Chronic corticosteroid therapy was utilized in 69% of patients and was associated with all vertebral fractures. A history of vitamin D deficiency occurred in 84%, and 35% were currently deficient. Despite chronic vitamin D supplementation, 38% remained deficient. These results demonstrate that osteoporosis and fracture remain major concerns in Duchenne muscular dystrophy. Bone health should be optimized well before loss of ambulation, however current levels of vitamin D supplementation may be inadequate given high levels of deficiency. © The Author(s) 2016.

Life-history variation of a neotropical thrush challenges food limitation theory

Science.gov (United States)

Ferretti, V.; Llambias, P.E.; Martin, T.E.

2005-01-01

Since David Lack first proposed that birds rear as many young as they can nourish, food limitation has been accepted as the primary explanation for variation in clutch size and other life-history traits in birds. The importance of food limitation in life-history variation, however, was recently questioned on theoretical grounds. Here, we show that clutch size differences between two populations of a neotropical thrush were contrary to expectations under Lack's food limitation hypothesis. Larger clutch sizes were found in a population with higher nestling starvation rate (i.e. greater food limitation). We experimentally equalized clutches between populations to verify this difference in food limitation. Our experiment confirmed greater food limitation in the population with larger mean clutch size. In addition, incubation bout length and nestling growth rate were also contrary to predictions of food limitation theory. Our results demonstrate the inability of food limitation to explain differences in several life-history traits: clutch size, incubation behaviour, parental feeding rate and nestling growth rate. These life-history traits were better explained by inter-population differences in nest predation rates. Food limitation may be less important to life history evolution in birds than suggested by traditional theory. ?? 2005 The Royal Society.

Repeatability and heritability of reproductive traits in free-ranging snakes.

Science.gov (United States)

Brown, G P; Shine, R

2007-03-01

The underlying genetic basis of life-history traits in free-ranging animals is critical to the effects of selection on such traits, but logistical constraints mean that such data are rarely available. Our long-term ecological studies on free-ranging oviparous snakes (keelbacks, Tropidonophis mairii (Gray, 1841), Colubridae) on an Australian floodplain provide the first such data for any tropical reptile. All size-corrected reproductive traits (egg mass, clutch size, clutch mass and post-partum maternal mass) were moderately repeatable between pairs of clutches produced by 69 female snakes after intervals of 49-1152 days, perhaps because maternal body condition was similar between clutches. Parent-offspring regression of reproductive traits of 59 pairs of mothers and daughters revealed high heritability for egg mass (h2= 0.73, SE=0.24), whereas heritability for the other three traits was low (snakes occurs because each female snake must allocate a finite amount of energy into eggs of a genetically determined size.

Life-history strategies as a tool to identify conservation constraints: A case-study on ants in chalk grasslands

NARCIS (Netherlands)

Noordwijk, C.G.E.; Boer, P.; Mabelis, A.A.; Verberk, W.C.E.P.; Siepel, H.

2012-01-01

Species’ life-history traits underlie species–environment relationships. Therefore, analysis of species traits, combined into life-history strategies, can be used to identify key factors shaping the local species composition. This is demonstrated in a case-study on ants in chalk grasslands. We

Invader population speeds up life history during colonization

OpenAIRE

Amundsen, Per-Arne; Salonen, Erno; Niva, Teuvo; Gjelland, Karl Øystein; Præbel, Kim; Sandlund, Odd Terje; Knudsen, Rune; Bøhn, Thomas

2012-01-01

We explore the long-term developments in population biology and life history during the invasion and establishment of the fish species vendace Coregonus albula in a subarctic watercourse by comparing life-history traits and molecular genetic estimates between the source and the colonist population. The two populations exhibited highly contrasting life-history strategies. Relative to the source population, the colonist population was characterized by slower somatic growth rates, earlier sexual...

Macroevolution of life-history traits in passerine birds: adaptation and phylogenetic inertia.

Science.gov (United States)

Pienaar, Jason; Ilany, Amiyaal; Geffen, Eli; Yom-Tov, Yoram

2013-05-01

We used a recent passerine phylogeny and comparative method to evaluate the macroevolution of body and egg mass, incubation and fledging periods, time to independence and time with parents of the main passerine lineages. We hypothesised that passerine reproductive traits are affected by adaptation to both past and present environmental factors and phenotypic attributes such as body mass. Our results suggest that the evolution of body and egg mass, time to independence, incubation and fledging times are affected by strong phylogenetic inertia and that these breeding traits are all affected by body mass. Time with parents, where major lineages exhibit their own fixed optima and body mass does not have an effect, and clutch size which is affected by body mass and additionally by climate regimes, do not exhibit any phylogenetic inertia. © 2013 Blackwell Publishing Ltd/CNRS.

Reporting success rates in the treatment of vestibular schwannomas: are we accounting for the natural history?

Science.gov (United States)

Miller, Timothy; Lau, Tsz; Vasan, Rohit; Danner, Christopher; Youssef, A Samy; van Loveren, Harry; Agazzi, Siviero

2014-06-01

Stereotactic radiosurgery is generally accepted as one of the best treatment options for vestibular schwannomas. We question whether growth control is an accurate measure of success in vestibular schwannoma treatment. We aim to clarify the success rate of stereotactic radiosurgery and adjust the reported results to the benign natural history of untreated tumors. All articles were taken from a PubMed search of the English literature from the years 2000-2011. Inclusion criteria were articles containing the number of patients treated, radiation technique, average tumor size, follow-up time, and percentage of tumors growing during follow-up. Data were extracted from 19 articles. Success rates were adjusted using published data that 17% to 30% of vestibular schwannomas grow. The average reported success rate for stereotactic radiosurgery across all articles was 95.5%. When considering 17% or 30% natural growth without intervention, the adjusted success rates became 78.2% and 86.9% respectively. These rates were obtained by applying the natural history growth percentages to any tumors not reported to be growing before radiosurgical intervention. Success in the treatment of vestibular schwannomas with stereotactic radiosurgery is often defined as lack of further growth. Recent data on the natural growth history of vestibular schwannomas raise the question of whether this is the best definition of success. We have identified a lack of continuity regarding the reporting of success and emphasize the importance of the clarification of the success of radiosurgery to make informed decisions regarding the best treatment options for vestibular schwannoma. Copyright © 2014 Elsevier Ltd. All rights reserved.

Rett syndrome diagnostic criteria: lessons from the Natural History Study.

Science.gov (United States)

Percy, Alan K; Neul, Jeffrey L; Glaze, Daniel G; Motil, Kathleen J; Skinner, Steven A; Khwaja, Omar; Lee, Hye-Seung; Lane, Jane B; Barrish, Judy O; Annese, Fran; McNair, Lauren; Graham, Joy; Barnes, Katherine

2010-12-01

Analysis of 819 participants enrolled in the Rett syndrome (RTT) Natural History Study validates recently revised diagnostic criteria. 765 females fulfilled 2002 consensus criteria for classic (653/85.4%) or variant (112/14.6%) RTT. All participants classified as classic RTT fulfilled each revised main criterion; supportive criteria were not uniformly present. All variant RTT participants met at least 3 of 6 main criteria in the 2002, 2 of 4 main criteria in the current format, and 5 of 11 supportive criteria in both. This analysis underscores the critical role of main criteria for classic RTT; variant RTT requires both main and supportive criteria.

Identification of Marker-Trait Associations for Lint Traits in Cotton

Science.gov (United States)

Iqbal, Muhammad A.; Rahman, Mehboob-ur-

2017-01-01

Harvesting high quality lint, a long-awaited breeding goal—accomplished partly, can be achieved by identifying DNA markers which could be used for diagnosing cotton plants containing the desired traits. In the present studies, a total of 185 cotton genotypes exhibiting diversity for lint traits were selected from a set of 546 genotypes evaluated for fiber traits in 2009. These genotypes were extensively studied for three consecutive years (2011–2013) at three different locations. Significant genetic variations were found for average boll weight, ginning out turn (GOT), micronaire value, staple length, fiber bundle strength, and uniformity index. IR-NIBGE-3701 showed maximum GOT (43.63%). Clustering of genotypes using Ward's method was found more informative than that of the clusters generated by principal component analysis. A total of 382 SSRs were surveyed on 10 Gossypium hirsutum genotypes exhibiting contrasting fiber traits. Out of these, 95 polymorphic SSR primer pairs were then surveyed on 185 genotypes. The gene diversity averaged 0.191 and the polymorphic information content (PIC) averaged 0.175. Unweighted pair group method with arithmetic mean (UPGMA), principal coordinate analysis (PCoA), and STRUCTURE software grouped these genotypes into four major clusters each. Genetic distance within the clusters ranged from 0.0587 to 0.1030. A total of 47 (25.41%) genotypes exhibited shared ancestry. In total 6.8% (r2 ≥ 0.05) and 4.4% (r2 ≥ 0.1) of the marker pairs showed significant linkage disequilibrium (LD). A number of marker-trait associations (in total 75) including 13 for average boll weight, 18 for GOT percentage, eight for micronaire value, 18 for staple length, three for fiber bundle strength, and 15 for uniformity index were calculated. Out of these, MGHES-51 was associated with all the traits. Most of the marker-trait associations were novel while few validated the associations reported in the previous studies. High frequency of favorable

77 FR 19691 - Notice of Inventory Completion: Sam Noble Oklahoma Museum of Natural History, Norman, OK

Science.gov (United States)

2012-04-02

... Natural History, Norman, OK. The human remains and associated funerary objects were removed from Le Flore... Flore County, OK. The mound site was excavated by the Works Progress Administration (WPA), under the...

The natural history of congenitally corrected transposition of the great arteries.

Science.gov (United States)

Huhta, James

2011-01-01

The natural history of congenitally corrected transposition of the great arteries is of clinical/surgical importance once the fetus is born without heart block or signs of heart failure. Without significant tricuspid valve malformation, associated defects such as ventricular septal defect and left ventricular outflow obstruction can be repaired surgically. The mortality and long-term outcome appear to be linked strongly with the severity of tricuspid valve regurgitation. Some patients with an intact ventricular septum and no right ventricular dysfunction will live long lives without detection, and some women will successfully complete pregnancy.

Trait-aggressiveness and impulsivity: role of psychological resilience and childhood trauma in a sample of male prisoners.

Science.gov (United States)

Carli, Vladimir; Mandelli, Laura; Zaninotto, Leonardo; Alberti, Siegfried; Roy, Alec; Serretti, Alessandro; Sarchiapone, Marco

2014-01-01

One of the major challenges for research in the field of human aggression is the need to define the role of personality and trait-like dimensions, such as impulsivity and aggressiveness, in predisposing to violent behavior. 1) To determine whether trait- aggressiveness and impulsivity may be associated with socio-demographic, clinical and crime history variables in a sample of male prisoners; 2) to detect any association of those traits with measures of early traumatic experiences and current resilience traits. A sample of male prisoners (n = 1356) underwent the Brown-Goodwin Assessment for Lifetime History of Aggression (BGLHA) and the Barratt Impulsivity Scale (BIS). Axis I psychiatric disorders were also assessed. Early traumatic experiences and psychological resilience were detected respectively by the Childhood Trauma Questionnaire (CTQ) and the Connor-Davidson Resilience Scale (CD-RISC). Two non-linear logistic regression models were performed to test for the best predictors of trait-aggressiveness and impulsivity. Subjects with a history of substance use disorders and self-mutilation reported both higher BGLHA and BIS scores. Axis I disorders and suicide attempts were associated with aggressiveness, but not to impulsivity. A consistent correlation was found between BGLHA scores and early traumatic experiences. Resilience was positively correlated to impulsivity but not to aggressiveness scores. Our results support the view that aggressiveness and impulsivity are two different, albeit related trait-like dimensions of personality, having a different relationship with resilience, and, inferentially, a different impact over the development of psychiatric disorders.

Personality traits and personal values: a meta-analysis.

Science.gov (United States)

Parks-Leduc, Laura; Feldman, Gilad; Bardi, Anat

2015-02-01

Personality traits and personal values are important psychological characteristics, serving as important predictors of many outcomes. Yet, they are frequently studied separately, leaving the field with a limited understanding of their relationships. We review existing perspectives regarding the nature of the relationships between traits and values and provide a conceptual underpinning for understanding the strength of these relationships. Using 60 studies, we present a meta-analysis of the relationships between the Five-Factor Model (FFM) of personality traits and the Schwartz values, and demonstrate consistent and theoretically meaningful relationships. However, these relationships were not generally large, demonstrating that traits and values are distinct constructs. We find support for our premise that more cognitively based traits are more strongly related to values and more emotionally based traits are less strongly related to values. Findings also suggest that controlling for personal scale-use tendencies in values is advisable. © 2014 by the Society for Personality and Social Psychology, Inc.

Generalised extreme value distributions provide a natural hypothesis for the shape of seed mass distributions.

Directory of Open Access Journals (Sweden)

Will Edwards

Full Text Available Among co-occurring species, values for functionally important plant traits span orders of magnitude, are uni-modal, and generally positively skewed. Such data are usually log-transformed "for normality" but no convincing mechanistic explanation for a log-normal expectation exists. Here we propose a hypothesis for the distribution of seed masses based on generalised extreme value distributions (GEVs, a class of probability distributions used in climatology to characterise the impact of event magnitudes and frequencies; events that impose strong directional selection on biological traits. In tests involving datasets from 34 locations across the globe, GEVs described log10 seed mass distributions as well or better than conventional normalising statistics in 79% of cases, and revealed a systematic tendency for an overabundance of small seed sizes associated with low latitudes. GEVs characterise disturbance events experienced in a location to which individual species' life histories could respond, providing a natural, biological explanation for trait expression that is lacking from all previous hypotheses attempting to describe trait distributions in multispecies assemblages. We suggest that GEVs could provide a mechanistic explanation for plant trait distributions and potentially link biology and climatology under a single paradigm.

Are all intertidal wetlands naturally created equal? Bottlenecks, thresholds and knowledge gaps to mangrove and saltmarsh ecosystems

Science.gov (United States)

Friess, Daniel A.; Krauss, Ken W.; Horstman, Erik M.; Balke, Thorsten; Bouma, Tjeerd J.; Galli, Demis; Webb, Edward L.

2011-01-01

Intertidal wetlands such as saltmarshes and mangroves provide numerous important ecological functions, though they are in rapid and global decline. To better conserve and restore these wetland ecosystems, we need an understanding of the fundamental natural bottlenecks and thresholds to their establishment and long-term ecological maintenance. Despite inhabiting similar intertidal positions, the biological traits of these systems differ markedly in structure, phenology, life history, phylogeny and dispersal, suggesting large differences in biophysical interactions. By providing the first systematic comparison between saltmarshes and mangroves, we unravel how the interplay between species-specific life-history traits, biophysical interactions and biogeomorphological feedback processes determine where, when and what wetland can establish, the thresholds to long-term ecosystem stability, and constraints to genetic connectivity between intertidal wetland populations at the landscape level. To understand these process interactions, research into the constraints to wetland development, and biological adaptations to overcome these critical bottlenecks and thresholds requires a truly interdisciplinary approach.

Defining SOD1 ALS natural history to guide therapeutic clinical trial design.

Science.gov (United States)

Bali, Taha; Self, Wade; Liu, Jingxia; Siddique, Teepu; Wang, Leo H; Bird, Thomas D; Ratti, Elena; Atassi, Nazem; Boylan, Kevin B; Glass, Jonathan D; Maragakis, Nicholas J; Caress, James B; McCluskey, Leo F; Appel, Stanley H; Wymer, James P; Gibson, Summer; Zinman, Lorne; Mozaffar, Tahseen; Callaghan, Brian; McVey, April L; Jockel-Balsarotti, Jennifer; Allred, Peggy; Fisher, Elena R; Lopate, Glenn; Pestronk, Alan; Cudkowicz, Merit E; Miller, Timothy M

2017-02-01

Understanding the natural history of familial amyotrophic lateral sclerosis (ALS) caused by SOD1 mutations (ALS SOD1 ) will provide key information for optimising clinical trials in this patient population. To establish an updated natural history of ALS SOD1 . Retrospective cohort study from 15 medical centres in North America evaluated records from 175 patients with ALS with genetically confirmed SOD1 mutations, cared for after the year 2000. Age of onset, survival, ALS Functional Rating Scale (ALS-FRS) scores and respiratory function were analysed. Patients with the A4V (Ala-Val) SOD1 mutation (SOD1 A4V ), the largest mutation population in North America with an aggressive disease progression, were distinguished from other SOD1 mutation patients (SOD1 non-A4V ) for analysis. Mean age of disease onset was 49.7±12.3 years (mean±SD) for all SOD1 patients, with no statistical significance between SOD1 A4V and SOD1 non-A4V (p=0.72, Kruskal-Wallis). Total SOD1 patient median survival was 2.7 years. Mean disease duration for all SOD1 was 4.6±6.0 and 1.4±0.7 years for SOD1 A4V . SOD1 A4V survival probability (median survival 1.2 years) was significantly decreased compared with SOD1 non-A4V (median survival 6.8 years; p<0.0001, log-rank). A statistically significant increase in ALS-FRS decline in SOD1 A4V compared with SOD1 non-A4V participants (p=0.02) was observed, as well as a statistically significant increase in ALS-forced vital capacity decline in SOD1 A4V compared with SOD1 non-A4V (p=0.02). SOD1 A4V is an aggressive, but relatively homogeneous form of ALS. These SOD1-specific ALS natural history data will be important for the design and implementation of clinical trials in the ALS SOD1 patient population. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

The natural history of fibroids.

Science.gov (United States)

Mavrelos, D; Ben-Nagi, J; Holland, T; Hoo, W; Naftalin, J; Jurkovic, D

2010-02-01

Fibroids are common, hormone-dependent, benign uterine tumors. They can cause significant morbidity and the symptoms depend largely on their size. The aim of this study was to describe the natural history of fibroids and identify factors that may influence their growth. This was a retrospective longitudinal study of premenopausal women who were diagnosed with uterine fibroids on ultrasound examination. All women underwent at least two transvaginal ultrasound scans, which were all performed by a single operator. Fibroids were measured in three perpendicular planes and the mean diameter was calculated. The size and position of every individual fibroid was assessed and recorded on a computerized database. The volume of each fibroid was calculated using the formula for a sphere. A total of 122 women were included in the study. Their median age at the initial examination was 40 (range, 27-45) years. Seventy-two (59.0%) were nulliparous and 74 (60.7%) had multiple fibroids. The median interval between the initial and final examination was 21.5 (range, 8-90) months. The median fibroid volume increased by 35.2% per year. Small fibroids (< 20 mm mean diameter) grew significantly faster than larger fibroids (P = 0.007). The median increase in size was significantly higher in cases of intramural fibroids (53.2 (interquartile range (IQR), 11.2-217)%) than in subserous fibroids (25.1 (IQR, 1.1-87.1)%) and submucous fibroids (22.8 (IQR, - 11.7 to 48.3)%) (P = 0.012). Multivariate analysis retained only fibroid size at presentation as an independent predictor of fibroid growth. The growth of fibroids in premenopausal women is influenced by the tumor's size at presentation.

Cellular metabolic rate is influenced by life-history traits in tropical and temperate birds.

Science.gov (United States)

Jimenez, Ana Gabriela; Van Brocklyn, James; Wortman, Matthew; Williams, Joseph B

2014-01-01

In general, tropical birds have a "slow pace of life," lower rates of whole-animal metabolism and higher survival rates, than temperate species. A fundamental challenge facing physiological ecologists is the understanding of how variation in life-history at the whole-organism level might be linked to cellular function. Because tropical birds have lower rates of whole-animal metabolism, we hypothesized that cells from tropical species would also have lower rates of cellular metabolism than cells from temperate species of similar body size and common phylogenetic history. We cultured primary dermal fibroblasts from 17 tropical and 17 temperate phylogenetically-paired species of birds in a common nutritive and thermal environment and then examined basal, uncoupled, and non-mitochondrial cellular O2 consumption (OCR), proton leak, and anaerobic glycolysis (extracellular acidification rates [ECAR]), using an XF24 Seahorse Analyzer. We found that multiple measures of metabolism in cells from tropical birds were significantly lower than their temperate counterparts. Basal and uncoupled cellular metabolism were 29% and 35% lower in cells from tropical birds, respectively, a decrease closely aligned with differences in whole-animal metabolism between tropical and temperate birds. Proton leak was significantly lower in cells from tropical birds compared with cells from temperate birds. Our results offer compelling evidence that whole-animal metabolism is linked to cellular respiration as a function of an animal's life-history evolution. These findings are consistent with the idea that natural selection has uniquely fashioned cells of long-lived tropical bird species to have lower rates of metabolism than cells from shorter-lived temperate species.

Cellular metabolic rate is influenced by life-history traits in tropical and temperate birds.

Directory of Open Access Journals (Sweden)

Ana Gabriela Jimenez

Full Text Available In general, tropical birds have a "slow pace of life," lower rates of whole-animal metabolism and higher survival rates, than temperate species. A fundamental challenge facing physiological ecologists is the understanding of how variation in life-history at the whole-organism level might be linked to cellular function. Because tropical birds have lower rates of whole-animal metabolism, we hypothesized that cells from tropical species would also have lower rates of cellular metabolism than cells from temperate species of similar body size and common phylogenetic history. We cultured primary dermal fibroblasts from 17 tropical and 17 temperate phylogenetically-paired species of birds in a common nutritive and thermal environment and then examined basal, uncoupled, and non-mitochondrial cellular O2 consumption (OCR, proton leak, and anaerobic glycolysis (extracellular acidification rates [ECAR], using an XF24 Seahorse Analyzer. We found that multiple measures of metabolism in cells from tropical birds were significantly lower than their temperate counterparts. Basal and uncoupled cellular metabolism were 29% and 35% lower in cells from tropical birds, respectively, a decrease closely aligned with differences in whole-animal metabolism between tropical and temperate birds. Proton leak was significantly lower in cells from tropical birds compared with cells from temperate birds. Our results offer compelling evidence that whole-animal metabolism is linked to cellular respiration as a function of an animal's life-history evolution. These findings are consistent with the idea that natural selection has uniquely fashioned cells of long-lived tropical bird species to have lower rates of metabolism than cells from shorter-lived temperate species.

Tension in the Natural History of Human Thinking

Directory of Open Access Journals (Sweden)

Moll Henrike

2016-03-01

Full Text Available Michael Tomasello has greatly expanded our knowledge of human cognition and how it differs from that of other animals. In this commentary to his recent book A Natural History of Human Thinking, I first critique some of the presuppositions and arguments of his evolutionary story about how homo sapiens’ cognition emerged. For example, I question the strategy of relying on the modern chimpanzee as a model for our last shared ancestor, and I doubt the idea that what changed first over evolutionary time was hominin behavior, which then in turn brought about changes in cognition. In the second half of the commentary I aim to show that the author oscillates between an additive and a transformative account of human shared intentionality. I argue that shared intentionality shapes cognition in its entirety and therefore precludes the possibility that humans have the same, individual intentionality (as shown in, e.g. their instrumental reasoning as other apes.

Predicting Risk-Mitigating Behaviors From Indecisiveness and Trait Anxiety

DEFF Research Database (Denmark)

Mcneill, Ilona M.; Dunlop, Patrick D.; Skinner, Timothy C.

2016-01-01

Past research suggests that indecisiveness and trait anxiety may both decrease the likelihood of performing risk-mitigating preparatory behaviors (e.g., preparing for natural hazards) and suggests two cognitive processes (perceived control and worrying) as potential mediators. However, no single...... control over wildfire-related outcomes. Trait anxiety did not uniquely predict preparedness or perceived control, but it did uniquely predict worry, with higher trait anxiety predicting more worrying. Also, worry trended toward uniquely predicting preparedness, albeit in an unpredicted positive direction...

Post-Mastectomy and Phantom Breast Pain: Risk Factors, Natural History, and Impact on Quality of Life

National Research Council Canada - National Science Library

Dworkin, Robert

1999-01-01

... from substantial reductions in quality of life. The primary aims of this research project are to identify risk factors for these chronic pain syndromes following surgical procedures for breast cancer, characterize their natural history...

[Regenerative morphological traits in a woody species community in Tumbesian tropical dry forest].

Science.gov (United States)

Romero-Saritama, José Miguel; Pérez-Rúuz, César

2016-06-01

The study of functional morphological traits enables us to know fundamental aspects of the dynamics of plant communities in local and global habitats. Regenerative morphological traits play an important role in defining plant history and ecological behavior. Seed and fruit characteristics determine to a large extent the patterns for dispersal, germination, establishment and seedling recruitment a given species exhibits on its natural habitat. Despite their prominent role, seed and fruit traits have been poorly studied at the community level of woody plant species in neo-tropical dry forests. In the present study we aimed at i) evaluate the functional role of morphological traits of seeds, fruits and embryo in woody plant species; ii) determine which are the morphological patterns present in seeds collected from the community of woody species that occur in neo-tropical dry forests; and iii) compare woody plant species seed mass values comparatively between neo-tropical dry and tropical forests. To do so, mature seeds were collected from 79 plant species that occur in the Tumbesian forest of Southwest Ecuador. The studied species included the 42 and 37 most representative tree and shrubbery species of the Tumbesian forest respectively. A total of 18 morphological traits (seven quantitative and 11 qualitative) were measured and evaluated in the seeds, fruits and embryos of the selected species, and we compared the seeds mass with other forest types. Our results showed a huge heterogeneity among traits values in the studied species. Seed mass, volume and number were the traits that vary the most at the community level, i.e. seed length ranged from 1.3 to 39 mm, and seed width from 0.6 to 25 mm. Only six embryo types were found among the 79 plant species. In 40 % of the cases, fully developed inverted embryos with large and thick cotyledons to store considerable amount of nutrients were recorded. We concluded that highly variable and functionally complementary

Paternal effects on early life history traits in Northwest Atlantic cod, Gadus morhua

DEFF Research Database (Denmark)

Kroll, M.-M.; Peck, M.A.; Butts, Ian A.E.

2013-01-01

It is important to understand parental effects on early life history of fish as manifested, for example, in individual fitness of offspring. Immediately after fertilization, parental contributions (both genetic and non-genetic) to embryos will affect larval ontogeny, physiology, morphology...... and survival. In marine fish, rates of natural mortality are highest during early life and are negatively correlated with rates of growth and body size. In these early life stages (eggs, larvae, young juveniles) subtle differences in mortality can cause large differences in recruitment and year-class success...... and can serve as important sources of variation during early life stages in fishes. Overall, these findings have implications for furthering the understanding of recruitment variability and can be used to optimize reproductive output for the aquaculture industry. In addition, the data suggests...

Trait-based approaches in the analysis of stream fish communities

Science.gov (United States)

Frimpong, Emmanuel; Angermeier, Paul

2010-01-01

Species traits are used to study the functional organization of fish communities for a range of reasons, from simply reducing data dimensionality to providing mechanistic explanations for observed variation in communities. Ecological and life history traits have been used to understand the basic ecology of fishes and predict (1) species and community responses to habitat and climate alteration, and (2) species extinction, species invasion, and community homogenization. Many approaches in this arena have been developed during the past three decades, but they often have not been integrated with related ecological concepts or subdisciplines, which has led to confusion in terminology. We review 102 studies of species traits and then summarize patterns in traits being used and questions being addressed with trait-based approaches. Overall, studies of fish–habitat relationships that apply habitat templates and hierarchical filters dominate our sample; the most frequently used traits are related to feeding. We define and show the relationships among key terms such as fundamental and realized niches; functional traits, performance, and fitness; tactic, trait-state, syndromes, and strategies; and guilds and functional groups. We propose accelerating research to (1) quantify trait plasticity, (2) identify traits useful for testing ecological hypotheses, (3) model habitat and biotic interactions in communities while explicitly accounting for phylogenetic relationships, (4) explore how traits control community assembly, and (5) document the importance of traits in fish– community responses to anthropogenic change and in delivering ecosystem services. Further synthesis of these topics is still needed to develop concepts, models, and principles that can unify the disparate approaches taken in trait-based analysis of fish communities, link fish community ecology to general community ecology, and inform sustainable management of ecosystems.

Cooperative Learning about Nature of Science with a Case from the History of Science

Science.gov (United States)

Wolfensberger, Balz; Canella, Claudia

2015-01-01

This paper reports a predominantly qualitative classroom study on cooperative learning about nature of science (NOS) using a case from the history of science. The purpose of the research was to gain insight into how students worked with the historical case study during cooperative group work, how students and teachers assessed the teaching unit,…

The Natural History of Oral Human Papillomavirus in Young Costa Rican Women.

Science.gov (United States)

Beachler, Daniel C; Lang Kuhs, Krystle A; Struijk, Linda; Schussler, John; Herrero, Rolando; Porras, Carolina; Hildesheim, Allan; Cortes, Bernal; Sampson, Joshua; Quint, Wim; Gonzalez, Paula; Kreimer, Aimée R

2017-07-01

Oral human papillomavirus (HPV) infection and related oropharyngeal cancer are uncommon in lower-income countries, particularly compared to HPV-associated cervical cancer. However, little is known about the natural history of oral HPV in less-developed settings and how it compares to the natural history of cervical HPV. Three hundred fifty women aged 22 to 33 years from the Costa Rica Vaccine Trial provided exfoliated cells from the cervical and oral regions at 2 visits 2 years apart. Samples from both visits were tested for 25 characterized α HPV types by the SPF10 PCR-DNA enzyme immunoassay-LiPA25 version 1 system. Risk factors for oral HPV persistence were calculated utilizing generalized estimating equations with a logistic link. Among the 82 women with characterized α oral HPV DNA detected at baseline, 14 persisted and were detected 2 years later (17.6%; 95% confidence interval [CI], 10.9-28.5%) and was similar to the persistence of α cervical HPV (40/223; 17.7%; 95% CI, 13.1-23.9%; P = 0.86). Acquisition of new α oral HPV type was low; incident infection (1.7%; 95% CI, 0.6-3.7%). Oral HPV DNA is uncommon in young women in Latin America, and often appears to clear within a few years at similar rates to cervical HPV.

Natural history of the lizard Enyalius iheringii (Squamata, Leiosauridae in southern Brazilian Atlantic forest

Directory of Open Access Journals (Sweden)

Ricardo Rautenberg

2010-12-01

Full Text Available Studies on the natural history of the lizard Enyalius iheringii Boulenger, 1885, as well as other tropical lizards, are rare. In this study, some aspects of the natural history of this endemic species from the Atlantic forest are reported in areas of Vale do Itajaí, state of Santa Catarina, Brazil. Twenty individuals were found, of which 18 were collected. Most of them were found over the vegetation (n=17 and on the ground (n=3. The main defensive strategy displayed was camouflage (n=16. Jumping (n=1, jumping and running (n=1 and running (n=2 were also observed in some individuals. When handled, lizards exhibited mouth wide open, hissing, and occasionally biting, as well as color change in males. Regarding its diet, the numerically most important prey was beetles (Coleoptera, followed by Lepidoptera larvae. Beetles, lepidopteran larvae and spiders were the most frequent food items. Males and females did not differ in size. Three sexually mature females (100-113 mm SVL were found in December and January.

Outcrossing and crossbreeding recovers deteriorated traits in laboratory cultured Steinernema carpocapsae nematodes.

Science.gov (United States)

Chaston, John M; Dillman, Adler R; Shapiro-Ilan, David I; Bilgrami, Anwar L; Gaugler, Randy; Hopper, Keith R; Adams, Byron J

2011-06-01

The nematode Steinernema carpocapsae infects and kills many pest insects in agro-ecosystems and is commonly used in biocontrol of these pests. Growth of the nematodes prior to distribution for biocontrol commonly results in deterioration of traits that are essential for nematode persistence in field applications. To better understand the mechanisms underlying trait deterioration of the efficacy of natural parasitism in entomopathogenic nematodes, we explored the maintenance of fitness related traits including reproductive capacity, heat tolerance, virulence to insects and 'tail standing' (formerly called nictation) among laboratory-cultured lines derived from natural, randomly mating populations of S. carpocapsae. Laboratory cultured nematode lines with fitness-related trait values below wild-type levels regained wild-type levels of reproductive and heat tolerance traits when outcrossed with a non-deteriorated line, while virulence and 'tail standing' did not deteriorate in our experiments. Crossbreeding two trait-deteriorated lines with each other also resulted in restoration of trait means to wild-type levels in most crossbred lines. Our results implicate inbreeding depression as the primary cause of trait deterioration in the laboratory cultured S. carpocapsae. We further suggest the possibility of creating inbred lines purged of deleterious alleles as founders in commercial nematode growth. Copyright © 2011 Australian Society for Parasitology Inc. All rights reserved.

Phylogenetic constraints in key functional traits behind species' climate niches

DEFF Research Database (Denmark)

Kellermann, Vanessa; Loeschcke, Volker; Hoffmann, Ary A

2012-01-01

Species distributions are often constrained by climatic tolerances that are ultimately determined by evolutionary history and/or adaptive capacity, but these factors have rarely been partitioned. Here, we experimentally determined two key climatic niche traits (desiccation and cold resistance) fo...

Can sexual selection drive female life histories? A comparative study on Galliform birds

OpenAIRE

Kolm, N.; Stein, R. W.; Mooers, A. O.; Verspoor, J. J.; Cunningham, E. J. A.

2007-01-01

Sexual selection has been identified as a major evolutionary force shaping male life history traits but its impact on female life history evolution is less clear. Here we examine the impact of sexual selection on three key female traits (body size, egg size and clutch size) in Galliform birds. Using comparative independent contrast analyses and directional DISCRETE analyses, based on published data and a new genera-level supertree phylogeny of Galliform birds, we investigated how sexual selec...

Interactions between cyanobacteria and gastropods II. Impact of toxic Planktothrix agardhii on the life-history traits of Lymnaea stagnalis.

Science.gov (United States)

Lance, Emilie; Paty, Chrystelle; Bormans, Myriam; Brient, Luc; Gérard, Claudia

2007-03-30

Hepatotoxins are frequently produced by many cyanobacterial species. Microcystins (MCs) are the most frequent and widely studied hepatotoxins, with potentially hazardous repercussions on aquatic organisms. As a ubiquitous herbivore living in eutrophic freshwaters, the snail Lymnaea stagnalis (Gastropoda: Pulmonata) is particularly exposed to cyanobacteria. The toxic filamentous Planktothrix agardhii is common in temperate lakes and is therefore, a potential food resource for gastropods. In the first part of this study, we demonstrated the ingestion of toxic P. agardhii by L. stagnalis during a 5 weeks exposure, with concomitant accumulation of, on average, 60% of total MCs ingested. After 3 weeks of non-toxic food (lettuce), approximately 90% of MCs were eliminated from tissues. Here, we investigate the impact of toxic P. agardhii consumption on the life-history traits (survival, growth and fecundity), locomotion and the structure of digestive and genital glands of juvenile and adult L. stagnalis. We observed a decrease of growth regardless of age, although this was more marked in juveniles, and a reduction of fecundity in adults. Survival and locomotion were not affected. Reduction of growth and fecundity continued to be observed even after feeding of non-toxic food for 3 weeks. The structure of the digestive gland was altered during the intoxication period but not irreversibly as cells tended to recover a normal status after the 3-week detoxification period. No histopathological changes occurred in the genital gland and oocytes, and spermatozoids were present in the gonadic acini. The density of cyanobacterial suspensions used in this study was comparable to those regularly observed in lakes, particularly in eutrophic waters. These results are discussed in terms of the negative impact of toxic cyanobacteria on natural communities of freshwater gastropods, and potential cascading effects on the equilibrium and functioning of the ecosystem.

Predicting personality traits related to consumer behavior using SNS analysis

Science.gov (United States)

Baik, Jongbum; Lee, Kangbok; Lee, Soowon; Kim, Yongbum; Choi, Jayoung

2016-07-01

Modeling a user profile is one of the important factors for devising a personalized recommendation. The traditional approach for modeling a user profile in computer science is to collect and generalize the user's buying behavior or preference history, generated from the user's interactions with recommender systems. According to consumer behavior research, however, internal factors such as personality traits influence a consumer's buying behavior. Existing studies have tried to adapt the Big 5 personality traits to personalized recommendations. However, although studies have shown that these traits can be useful to some extent for personalized recommendation, the causal relationship between the Big 5 personality traits and the buying behaviors of actual consumers has not been validated. In this paper, we propose a novel method for predicting the four personality traits-Extroversion, Public Self-consciousness, Desire for Uniqueness, and Self-esteem-that correlate with buying behaviors. The proposed method automatically constructs a user-personality-traits prediction model for each user by analyzing the user behavior on a social networking service. The experimental results from an analysis of the collected Facebook data show that the proposed method can predict user-personality traits with greater precision than methods that use the variables proposed in previous studies.

Quantifying the effects of ecological constraints on trait expression using novel trait-gradient analysis parameters.

Science.gov (United States)

Ottaviani, Gianluigi; Tsakalos, James L; Keppel, Gunnar; Mucina, Ladislav

2018-01-01

Complex processes related to biotic and abiotic forces can impose limitations to assembly and composition of plant communities. Quantifying the effects of these constraints on plant functional traits across environmental gradients, and among communities, remains challenging. We define ecological constraint ( C i ) as the combined, limiting effect of biotic interactions and environmental filtering on trait expression (i.e., the mean value and range of functional traits). Here, we propose a set of novel parameters to quantify this constraint by extending the trait-gradient analysis (TGA) methodology. The key parameter is ecological constraint, which is dimensionless and can be measured at various scales, for example, on population and community levels. It facilitates comparing the effects of ecological constraints on trait expressions across environmental gradients, as well as within and among communities. We illustrate the implementation of the proposed parameters using the bark thickness of 14 woody species along an aridity gradient on granite outcrops in southwestern Australia. We found a positive correlation between increasing environmental stress and strength of ecological constraint on bark thickness expression. Also, plants from more stressful habitats (shrublands on shallow soils and in sun-exposed locations) displayed higher ecological constraint for bark thickness than plants in more benign habitats (woodlands on deep soils and in sheltered locations). The relative ease of calculation and dimensionless nature of C i allow it to be readily implemented at various scales and make it widely applicable. It therefore has the potential to advance the mechanistic understanding of the ecological processes shaping trait expression. Some future applications of the new parameters could be investigating the patterns of ecological constraints (1) among communities from different regions, (2) on different traits across similar environmental gradients, and (3) for the same

Pervasive gene expression responses to a fluctuating diet in Drosophila melanogaster: The importance of measuring multiple traits to decouple potential mediators of life span and reproduction.

Science.gov (United States)

Zandveld, Jelle; van den Heuvel, Joost; Mulder, Maarten; Brakefield, Paul M; Kirkwood, Thomas B L; Shanley, Daryl P; Zwaan, Bas J

2017-11-01

Phenotypic plasticity is an important concept in life-history evolution, and most organisms, including Drosophila melanogaster, show a plastic life-history response to diet. However, little is known about how these life-history responses are mediated. In this study, we compared adult female flies fed an alternating diet (yoyo flies) with flies fed a constant low (CL) or high (CH) diet and tested how whole genome expression was affected by these diet regimes and how the transcriptional responses related to different life-history traits. We showed that flies were able to respond quickly to diet fluctuations throughout life span by drastically changing their transcription. Importantly, by measuring the response of multiple life-history traits we were able to decouple groups of genes associated with life span or reproduction, life-history traits that often covary with a diet change. A coexpression network analysis uncovered which genes underpin the separate and shared regulation of these life-history traits. Our study provides essential insights to help unravel the genetic architecture mediating life-history responses to diet, and it shows that the flies' whole genome transcription response is highly plastic. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

Sahagún's "Florentine codex," a little known Aztecan natural history of the Valley of Mexico.

Science.gov (United States)

Reeves, Henry M

2006-01-01

Franciscan missionary Fray Bernardino de Sahagún arrived in New Spain (Mexico) in 1529 to proselytize Aztecs surviving the Conquest, begun by Hernán Cortés in 1519. About 1558 he commenced his huge opus "Historia general de las cosas de Nueva España" completed in Latin-Nahuatl manuscript in 1569. The best surviving version, the "Florentine Codex," 1579 in Spanish-Nahuatl, is the basis for the editions published since 1829. The first English translation was issued in 13 volumes between 1950 and 1982, and the first facsimile was published in 1979. Book 11, "Earthly things," is a comprehensive natural history of the Valley of Mexico based on pre-Cortésian Aztec knowledge. Sahagún's work, largely unknown among English-speaking biologists, is an untapped treasury of information about Aztecan natural history. It also establishes the Aztecs as the preeminent pioneering naturalists of North American, and Sahagún and his colleagues as their documentarians.

Life history theory predicts fish assemblage response to hydrologic regimes.

Science.gov (United States)

Mims, Meryl C; Olden, Julian D

2012-01-01

The hydrologic regime is regarded as the primary driver of freshwater ecosystems, structuring the physical habitat template, providing connectivity, framing biotic interactions, and ultimately selecting for specific life histories of aquatic organisms. In the present study, we tested ecological theory predicting directional relationships between major dimensions of the flow regime and life history composition of fish assemblages in perennial free-flowing rivers throughout the continental United States. Using long-term discharge records and fish trait and survey data for 109 stream locations, we found that 11 out of 18 relationships (61%) tested between the three life history strategies (opportunistic, periodic, and equilibrium) and six hydrologic metrics (two each describing flow variability, predictability, and seasonality) were statistically significant (P history strategies, with 82% of all significant relationships observed supporting predictions from life history theory. Specifically, we found that (1) opportunistic strategists were positively related to measures of flow variability and negatively related to predictability and seasonality, (2) periodic strategists were positively related to high flow seasonality and negatively related to variability, and (3) the equilibrium strategists were negatively related to flow variability and positively related to predictability. Our study provides important empirical evidence illustrating the value of using life history theory to understand both the patterns and processes by which fish assemblage structure is shaped by adaptation to natural regimes of variability, predictability, and seasonality of critical flow events over broad biogeographic scales.

Contrasting latitudinal patterns of life-history divergence in two genera of new world thrushes (Turdinae)

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Boyce, Andy J.; Martin, Thomas E.

2017-01-01

Several long-standing hypotheses have been proposed to explain latitudinal patterns of life-history strategies. Here, we test predictions of four such hypotheses (seasonality, food limitation, nest predation and adult survival probability) by examining life-history traits and age-specific mortality rates of several species of thrushes (Turdinae) based on field studies at temperate and tropical sites and data gathered from the literature. Thrushes in the genus Catharus showed the typical pattern of slower life-history strategies in the tropics while co-occuring Turdus thrushes differed much less across latitudes. Seasonality is a broadly accepted hypothesis for latitudinal patterns, but the lack of concordance in latitudinal patterns between co-existing genera that experience the same seasonal patterns suggests seasonality cannot fully explain latitudinal trait variation in thrushes. Nest-predation also could not explain patterns based on our field data and literature data for these two genera. Total feeding rates were similar, and per-nestling feeding rates were higher at tropical latitudes in both genera, suggesting food limitation does not explain trait differences in thrushes. Latitudinal patterns of life histories in these two genera were closely associated with adult survival probability. Thus, our data suggest that environmental influences on adult survival probability may play a particularly strong role in shaping latitudinal patterns of life-history traits.

Cellular Metabolic Rate Is Influenced by Life-History Traits in Tropical and Temperate Birds

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Jimenez, Ana Gabriela; Van Brocklyn, James; Wortman, Matthew; Williams, Joseph B.

2014-01-01

In general, tropical birds have a “slow pace of life,” lower rates of whole-animal metabolism and higher survival rates, than temperate species. A fundamental challenge facing physiological ecologists is the understanding of how variation in life-history at the whole-organism level might be linked to cellular function. Because tropical birds have lower rates of whole-animal metabolism, we hypothesized that cells from tropical species would also have lower rates of cellular metabolism than cells from temperate species of similar body size and common phylogenetic history. We cultured primary dermal fibroblasts from 17 tropical and 17 temperate phylogenetically-paired species of birds in a common nutritive and thermal environment and then examined basal, uncoupled, and non-mitochondrial cellular O2 consumption (OCR), proton leak, and anaerobic glycolysis (extracellular acidification rates [ECAR]), using an XF24 Seahorse Analyzer. We found that multiple measures of metabolism in cells from tropical birds were significantly lower than their temperate counterparts. Basal and uncoupled cellular metabolism were 29% and 35% lower in cells from tropical birds, respectively, a decrease closely aligned with differences in whole-animal metabolism between tropical and temperate birds. Proton leak was significantly lower in cells from tropical birds compared with cells from temperate birds. Our results offer compelling evidence that whole-animal metabolism is linked to cellular respiration as a function of an animal’s life-history evolution. These findings are consistent with the idea that natural selection has uniquely fashioned cells of long-lived tropical bird species to have lower rates of metabolism than cells from shorter-lived temperate species. PMID:24498080

Chasing a changing climate: Reproductive and dispersal traits predict how sessile species respond to global warming

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Archambault, Jennifer M.; Cope, W. Gregory; Kwak, Thomas J.

2018-01-01

AimStudies of species' range shifts have become increasingly relevant for understanding ecology and biogeography in the face of accelerated global change. The combination of limited mobility and imperilled status places some species at a potentially greater risk of range loss, extirpation or extinction due to climate change. To assess the ability of organisms with limited movement and dispersal capabilities to track shifts associated with climate change, we evaluated reproductive and dispersal traits of freshwater mussels (Unionida), sessile invertebrates that require species‐specific fish for larval dispersal.LocationNorth American Atlantic Slope rivers.MethodsTo understand how unionid mussels may cope with and adapt to current and future warming trends, we identified mechanisms that facilitated their colonization of the northern Atlantic Slope river basins in North America after the Last Glacial Maximum. We compiled species occurrence and life history trait information for each of 55 species, and then selected life history traits for which ample data were available (larval brooding duration, host fish specificity, host infection strategy, and body size) and analysed whether the trait state for each was related to mussel distribution in Atlantic Slope rivers.ResultsBrooding duration (p  .10).Main conclusionsOur results are potentially applicable to many species for which life history traits have not been well‐documented, because reproductive and dispersal traits in unionid mussels typically follow phylogenetic relationships. These findings may help resource managers prioritize species according to climate change vulnerability and predict which species might become further imperilled with climate warming. Finally, we suggest that similar trait‐based decision support frameworks may be applicable for other movement limited taxa.

Heritability and social brood effects on personality in juvenile and adult life-history stages in a wild passerine.

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Winney, I S; Schroeder, J; Nakagawa, S; Hsu, Y-H; Simons, M J P; Sánchez-Tójar, A; Mannarelli, M-E; Burke, T

2018-01-01

How has evolution led to the variation in behavioural phenotypes (personalities) in a population? Knowledge of whether personality is heritable, and to what degree it is influenced by the social environment, is crucial to understanding its evolutionary significance, yet few estimates are available from natural populations. We tracked three behavioural traits during different life-history stages in a pedigreed population of wild house sparrows. Using a quantitative genetic approach, we demonstrated heritability in adult exploration, and in nestling activity after accounting for fixed effects, but not in adult boldness. We did not detect maternal effects on any traits, but we did detect a social brood effect on nestling activity. Boldness, exploration and nestling activity in this population did not form a behavioural syndrome, suggesting that selection could act independently on these behavioural traits in this species, although we found no consistent support for phenotypic selection on these traits. Our work shows that repeatable behaviours can vary in their heritability and that social context influences personality traits. Future efforts could separate whether personality traits differ in heritability because they have served specific functional roles in the evolution of the phenotype or because our concept of personality and the stability of behaviour needs to be revised. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

Agency and industry : Charles C. Gillispie’s "The Natural History of Industry," then and now

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Roberts, Lissa L.

2013-01-01

Charles Coulston Gillispie’s “The Discovery of the Leblanc Process” and “The Natural History of Industry” (Isis 48 (1957): 152–70, 398–407) were unique, yet characteristic of their era. Together, they engaged with discussions of the historical relationship between science and industry. While

Trait modality distribution of aquatic macrofauna communities as explained by pesticides and water chemistry

OpenAIRE

Ieromina, O.; Musters, C. J. M.; Bodegom, P. M.; Peijnenburg, W. J. G. M.; Vijver, M. G.

2016-01-01

Analyzing functional species? characteristics (species traits) that represent physiological, life history and morphological characteristics of species help understanding the impacts of various stressors on aquatic communities at field conditions. This research aimed to study the combined effects of pesticides and other environmental factors (temperature, dissolved oxygen, dissolved organic carbon, floating macrophytes cover, phosphate, nitrite, and nitrate) on the trait modality distribution ...

History of natural resource use and environmental impacts in an interfluvial upland forest area in western Amazonia

OpenAIRE

Anders Siren

2014-01-01

Much of the research done on environmental impacts by Amazonian indigenous peoples in the past focus on certain areas where archaeological remains are particularly abundant, such as the Amazon River estuary, the seasonally inundated floodplain of the lower Amazon, and various sites in the forest-savannah mosaic of the southern Amazon The environmental history of interfluvial upland areas has received less attention. This study reconstructed the history of human use of natural resources in an ...

Changes in emotion regulation in adults with and without a history of childhood abuse following posttraumatic stress disorder treatment.

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Jerud, Alissa B; Zoellner, Lori A; Pruitt, Larry D; Feeny, Norah C

2014-08-01

This study compared changes in emotion regulation and trait affect over the course of PTSD treatment with either prolonged exposure (PE) therapy or sertraline in adults with and without a history of childhood abuse (CA). Two hundred adults with PTSD received 10 weeks of PE or sertraline. Emotion regulation and trait affect were assessed pre- and posttreatment and at 6-month follow-up with the Emotion Regulation Questionnaire (Gross & John, 2003), the Negative Mood Regulation Scale (Catanzaro & Mearns, 1990), and the Positive and Negative Affect Schedule (Watson, Clark, & Tellegen, 1988). Individuals with and without a history of CA did not differ from one another at pretreatment on PTSD severity, emotion regulation, or positive/negative affect. In addition, treatment was effective at improving emotion regulation and trait affect in those with and without a history of CA, and no significant differences in emotion regulation or trait affect emerged posttreatment or at 6-month follow-up between adults with and without a history of CA. Furthermore, noninferiority analyses indicated that the emotion regulation and trait affect outcomes of individuals with a history of CA were no worse than those of individuals without a history of CA. These findings cast doubt on the assumption that CA is associated with worse emotion regulation following PTSD treatment, arguing against assertions that a history of CA itself is a contraindication for traditional PTSD treatment, and that there is a clear necessity for additional interventions designed to target assumed emotion regulation deficits. [Corrected] PsycINFO Database Record (c) 2014 APA, all rights reserved.

NATURAL LAW, HISTORY AND POLITICS LEY NATURAL, HISTORIA Y POLÍTICA LEI NATURAL, HISTÓRIA E POLÍTICA

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James Drane

2002-01-01

Full Text Available The basic philosophical vision and ethical principles of Catholic Natural Law claim universality. Natural Law thinking aspires to objectivity and universality and at the same time is open to the continuing influence from history and politics. The background principles of positive law historically go by the name of Natural Law. Suffering and injustice contribute to a vision both of the structure of human existence and of what we mean by humane law and ethics. When we confront a cultural crisis, Natural Law, looks not to the past but to the future. Few people today talk of the ethical dimensions of social realities in terms of Natural Law. This is true both in the Church and in the State. In bioethics, the principles rooted in the universal structure of human life have to provide direction and regulations on the playing field of contemporary life and medicine. A liberal Catholic perspective tries to keep in play the universal and the particular aspects of Natural Law reasoningLa visión filosófica básica y los principios éticos de la Ley Natural Católica demandan universalidad. El pensamiento de la Ley Natural aspira a la objetividad y universalidad y, al mismo tiempo, está abierto a la continua influencia de la historia y la política. Los principios que yacen en la base de la ley positiva históricamente reciben el nombre de Ley Natural. El sufrimiento y la injusticia contribuyen a una visión, tanto de la estructura de la existencia humana como de lo que entendemos por una ley y una ética humanas. Cuando enfrentamos una crisis cultural, la Ley Natural no mira hacia el pasado sino que hacia el futuro. Es poca la gente que hoy en día habla de las dimensiones éticas de las realidades sociales en términos de Ley Natural. Esto vale tanto para la Iglesia como para el Estado. En bioética, los principios enraizados en la estructura universal de la vida humana tienen que proporcionar dirección y regulación en el campo de juego de la vida y

Natural history of severe atheromatous disease of the thoracic aorta: a transesophageal echocardiographic study.

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Montgomery, D H; Ververis, J J; McGorisk, G; Frohwein, S; Martin, R P; Taylor, W R

1996-01-01

This study sought to prospectively observe the morphologic and clinical natural history of severe atherosclerotic disease of the thoracic aorta as defined by transesophageal echocardiography. Atherosclerosis of the thoracic aorta has been shown to be highly associated with risk for embolic events in transesophageal studies, but the natural history of the disease under clinical conditions has not been reported. During a 20-month period, 191 of 264 patients undergoing transesophageal echocardiography had adequate visualization of the aorta to allow atherosclerotic severity to be graded as follows: grade I = normal (44 patients); grade II = intimal thickening (52 patients); grade III = atheroma or = 5 mm (19 patients); grade V = mobile lesion (14 patients). All available patients with grades IV (8 patients) and V (10 patients) disease as well as a subgroup of 12 patients with grade III disease had follow-up transesophageal echocardiographic studies (mean [+/- SD] 11.7 +/- 0.9 months, range 6 to 22). Of 30 patients undergoing follow-up transesophageal echocardiographic studies, 20 (66%) had no change in atherosclerotic severity grade. Of the remaining 10 patients, atherosclerotic severity progressed one grade in 7 and decreased in 3 with resolved mobile lesions. Of 18 patients with grade IV or V disease of the aorta who underwent a follow-up study, 11 (61%) demonstrated formation of new mobile lesions. Of 10 patients with grade V disease on initial study who underwent follow-up study, 7 (70%) demonstrated resolution of a specific previously documented mobile lesion. However, seven patients (70%) with grade V disease also demonstrated development of a new mobile lesion. Of 33 patients with grade IV or V disease, 8 (24%) died during the study period, and 1 (3%) had a clinical embolic event. The presence of severe atherosclerotic disease of the thoracic aorta as defined by transesophageal echocardiography is associated with a high mortality rate. Although the morphologic

Advances in modeling trait-based plant community assembly.

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Laughlin, Daniel C; Laughlin, David E

2013-10-01

In this review, we examine two new trait-based models of community assembly that predict the relative abundance of species from a regional species pool. The models use fundamentally different mathematical approaches and the predictions can differ considerably. Maxent obtains the most even probability distribution subject to community-weighted mean trait constraints. Traitspace predicts low probabilities for any species whose trait distribution does not pass through the environmental filter. Neither model maximizes functional diversity because of the emphasis on environmental filtering over limiting similarity. Traitspace can test for the effects of limiting similarity by explicitly incorporating intraspecific trait variation. The range of solutions in both models could be used to define the range of natural variability of community composition in restoration projects. Copyright © 2013 Elsevier Ltd. All rights reserved.

Culturas das Ciências Naturais Cultures of Natural Sciences

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Maria Margaret Lopes

2005-12-01

Full Text Available Este artigo apresenta subsídios para o ensino de História das Ciências, considerando particularmente o campo da História da História Natural e das Ciências Naturais. Sem ser uma revisão completa da historiografia desses campos de conhecimento sobre o mundo natural, retoma alguns traços gerais desses longos processos de definição de campos disciplinares que se configuram desde a Renascença até o final do século XVIII. Considera diversas tradições culturais e historiográficas que contribuíram para os nossos entendimentos atuais, de como a História Natural do Renascimento foi abandonando seus antigos quadros conceituais, assumindo novas práticas e se constituindo nas tradições da História Natural do século XVIII. Comenta esses processos, em que tanto a Botânica, a Zoologia, a Mineralogia se individualizam como áreas de conhecimentos apoiadas em práticas locais e coleções globais, indo além de sua subordinação à utilidade médica; bem como suas organizações em áreas de conhecimento, por começarem a se colocar questões relativas à origem e à historicidade dos seres e processos naturais, dados os avanços das temáticas classificatórias e das discussões envolvendo temporalidades.This paper provides insights into the teaching of the History of Science, especially the field of the History of Natural History and Natural Sciences. Although not claiming to be a complete historiographic review of these areas of knowledge about the natural world, it outlines the general traits of the long process of definition of disciplines that were shaped from the Renaissance to the end of the XVIII century. It encompasses various cultural and historiographic traditions that contributed to our present understanding of how Renaissance Natural History abandoned its ancient conceptual frameworks and assumed new practices and shaped itself in the tradition of XVIII century Natural History. The paper comments on these processes by which

Reproductive Behavior and Personality Traits of the Five Factor Model

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Jokela, Markus; Alvergne, Alexandra; Pollet, Thomas V.; Lummaa, Virpi

2011-01-01

We examined associations between Five Factor Model personality traits and various outcomes of reproductive behavior in a sample of 15 729 women and men from the Wisconsin Longitudinal Study (WLS) and Midlife Development in the United States (MIDUS) survey. Personality and reproductive history was

The natural history of class I primate alcohol dehydrogenases includes gene duplication, gene loss, and gene conversion.

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Matthew A Carrigan

Full Text Available Gene duplication is a source of molecular innovation throughout evolution. However, even with massive amounts of genome sequence data, correlating gene duplication with speciation and other events in natural history can be difficult. This is especially true in its most interesting cases, where rapid and multiple duplications are likely to reflect adaptation to rapidly changing environments and life styles. This may be so for Class I of alcohol dehydrogenases (ADH1s, where multiple duplications occurred in primate lineages in Old and New World monkeys (OWMs and NWMs and hominoids.To build a preferred model for the natural history of ADH1s, we determined the sequences of nine new ADH1 genes, finding for the first time multiple paralogs in various prosimians (lemurs, strepsirhines. Database mining then identified novel ADH1 paralogs in both macaque (an OWM and marmoset (a NWM. These were used with the previously identified human paralogs to resolve controversies relating to dates of duplication and gene conversion in the ADH1 family. Central to these controversies are differences in the topologies of trees generated from exonic (coding sequences and intronic sequences.We provide evidence that gene conversions are the primary source of difference, using molecular clock dating of duplications and analyses of microinsertions and deletions (micro-indels. The tree topology inferred from intron sequences appear to more correctly represent the natural history of ADH1s, with the ADH1 paralogs in platyrrhines (NWMs and catarrhines (OWMs and hominoids having arisen by duplications shortly predating the divergence of OWMs and NWMs. We also conclude that paralogs in lemurs arose independently. Finally, we identify errors in database interpretation as the source of controversies concerning gene conversion. These analyses provide a model for the natural history of ADH1s that posits four ADH1 paralogs in the ancestor of Catarrhine and Platyrrhine primates

[Science and nation: romanticism and natural history in the works of E. J. da Silva Maia].

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Kury, L

1998-01-01

The works of physician and naturalist Emílio Joaquim da Silva Maia (1808-59) can be viewed as a scientific project that discovers Brazil and its inhabitants. Maia's nationalism and his romantic view of nature formed the underpinnings of his scientific theories, especially his studies on zoological geography. He subordinated the issue of the biological specificity of different regions of the world to his era's debates on the construction of Brazil as an independent nation. In his interpretations of European natural history, Maia endeavored to understand Brazilian nature as a specific achievement of the Cosmos, in keeping with Alexander von Humboldt's approach.

Groupings of life-history traits are associated with distribution of forest plant species in a fragmented landscape

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Endels, Patrick; Adriaens, Dries; Bekker, Renee M.; Knevel, Irma C.; Decocq, Guillaume; Hermy, Martin

Questions: 1. Do relationships among forest plant traits correspond to dispersability-persistence trade-offs or other intertrait correlations found in the literature? 2. Do species groups delineated by trait similarity, differ in occurrence in ancient vs. new forests or isolated vs more continuous