521 research outputs found
The international school psychology survey: Data from Australia, China, Germany, Italy and Russia
Using the International School Psychology Survey (ISPS) this study aims to advance our knowledge of the characteristics, training, roles and responsibilities, challenges and research interests of school psychologists around the world. Data are presented from five countries; Australia, China (Hong Kong), Germany, Italy and Russia. The ISPS contributes valuable information regarding the profession of school psychology in each of these countries. Building upon the ISPS data previously gathered in Albania, Cyprus, Estonia, Greece and Northern England, this study yields additional information regarding the training, roles, responsibilities and contexts of school psychologists. Information from international colleagues provides unique insights regarding similarities, differences and diversity among school psychologists in different countries. © 2006 SAGE Publications.postprin
Evaluating the landscape of fear between apex predatory sharks and mobile sea turtles across a large dynamic seascape
The ‘‘landscape of fear’’ model has been proposed as a unifying concept in ecology, describing, in part, how animals behave and move about in their environment. The basic model predicts that as an animal’s landscape changes from low to high risk of predation,
prey species will alter their behavior to risk avoidance. However, studies investigating and evaluating the landscape of fear model across large spatial scales (tens to hundreds of thousands of square kilometers) in dynamic, open, aquatic systems involving apex predators and highly mobile prey are lacking. To address this knowledge gap, we investigated predator–prey relationships between tiger sharks (Galeocerdo cuvier) and loggerhead turtles (Caretta caretta) in the North Atlantic Ocean. This included the use of satellite tracking to examine shark and turtle distributions as well as their surfacing behaviors under varying levels of home range overlap. Our findings revealed patterns that deviated from our a priori predictions based on the landscape of fear model. Specifically, turtles did not alter their surfacing behaviors to risk avoidance when overlap in shark–turtle core home range was high. However, in areas of high overlap with turtles, sharks exhibited modified surfacing behaviors that may enhance predation opportunity. We suggest that turtles may be an important factor in determining shark distribution, whereas for turtles, other life history trade-offs may play a larger role in
defining their habitat use. We propose that these findings are a result of both biotic and physically driven factors that independently or synergistically affect predator–prey interactions in this system. These results have implications for evolutionary biology, community ecology, and wildlife conservation. Further, given the difficulty in studying highly migratory marine species, our approach and conclusions may be applied to the study of other predator–prey systems.Bald Head Island ConservancyBritish Chelonia GroupNatural Environmental Research CouncilWAVE Foundation/Newport Aquarium CincinnatiPADI project AWARESEATURTLE.ORGWhitener Foundation (NC); an Endangered Species Act Section 6 Cooperative Agreement with
NOAA Fisheries and the Grays Reef National Marine Sanctuary (South Carolina and Georgia)Batchelor FoundationDinsey Conservation Fun
Polarization due to rotational distortion in the bright star Regulus
This is the full published article (retrieved from the 6 months post-publication posting on arXiv) including the Methods and Supplementary Information sections: 33 pages, 10 figures, 8 tablesPolarization in stars was first predicted by Chandrasekhar [1] who calculated a substantial linear polarization at the stellar limb for a pure electron-scattering atmosphere. This polarization will average to zero when integrated over a spherical star but could be detected if the symmetry is broken, for example by the eclipse of a binary companion. Nearly 50 years ago, Harrington and Collins [2] modeled another way of breaking the symmetry and producing net polarization - the distortion of a rapidly rotating hot star. Here we report the first detection of this effect. Observations of the linear polarization of Regulus, with two different high-precision polarimeters, range from +42 parts-per-million (ppm) at a wavelength of 741 nm to -22 ppm at 395 nm. The reversal from red to blue is a distinctive feature of rotation-induced polarization. Using a new set of models for the polarization of rapidly rotating stars we find that Regulus is rotating at 96.5(+0.6/-0.8)% of its critical angular velocity for breakup, and has an inclination greater than 76.5 degrees. The rotation axis of the star is at a position angle of 79.5+/-0.7 degrees. The conclusions are independent of, but in good agreement with, the results of previously published interferometric observations of Regulus [3]. The accurate measurement of rotation in early-type stars is important for understanding their stellar environments [4], and course of their evolution [5].Peer reviewedFinal Accepted Versio
A rare exception to Haldane's rule: are X chromosomes key to hybrid incompatibilities?
This work was funded by NERC (NE/G014906/1, NE/L011255/1, NE/I027800/1). Additional funding from the Orthopterists’ Society to PM is also gratefully acknowledged.The prevalence of Haldane’s rule suggests that sex chromosomes commonly have a key role in reproductive barriers and speciation. However, the majority of research on Haldane’s rule has been conducted in species with conventional sex determination systems (XY and ZW) and exceptions to the rule have been understudied. Here we test the role of X-linked incompatibilities in a rare exception to Haldane’s rule for female sterility in field cricket sister species (Teleogryllus oceanicus and T. commodus). Both have an XO sex determination system. Using three generations of crosses, we introgressed X chromosomes from each species onto different, mixed genomic backgrounds to test predictions about the fertility and viability of each cross type. We predicted that females with two different species X chromosomes would suffer reduced fertility and viability compared with females with two parental X chromosomes. However, we found no strong support for such X-linked incompatibilities. Our results preclude X–X incompatibilities and instead support an interchromosomal epistatic basis to hybrid female sterility. We discuss the broader implications of these findings, principally whether deviations from Haldane’s rule might be more prevalent in species without dimorphic sex chromosomes.PostprintPeer reviewe
Wolbachia-Induced Unidirectional Cytoplasmic Incompatibility and Speciation: Mainland-Island Model
Bacteria of the genus Wolbachia are among the most common endosymbionts in the world. In many insect species these bacteria induce a sperm-egg incompatibility between the gametes of infected males and uninfected females, commonly called unidirectional cytoplasmic incompatibility (CI). It is generally believed that unidirectional CI cannot promote speciation in hosts because infection differences between populations will be unstable and subsequent gene flow will eliminate genetic differences between diverging populations. In the present study we investigate this question theoretically in a mainland-island model with migration from mainland to island. Our analysis shows that (a) the infection polymorphism is stable below a critical migration rate, (b) an (initially) uninfected “island” can better maintain divergence at a selected locus (e.g. can adapt locally) in the presence of CI, and (c) unidirectional CI selects for premating isolation in (initially) uninfected island populations if they receive migration from a Wolbachia-infected mainland. Interestingly, premating isolation is most likely to evolve if levels of incompatibility are intermediate and if either the infection causes fecundity reductions or Wolbachia transmission is incomplete. This is because under these circumstances an infection pattern with an infected mainland and a mostly uninfected island can persist in the face of comparably high migration. We present analytical results for all three findings: (a) a lower estimation of the critical migration rate in the presence of local adaptation, (b) an analytical approximation for the gene flow reduction caused by unidirectional CI, and (c) a heuristic formula describing the invasion success of mutants at a mate preference locus. These findings generally suggest that Wolbachia-induced unidirectional CI can be a factor in divergence and speciation of hosts
Haldane's rule in the 21st century
Haldane's Rule (HR), which states that 'when in the offspring of two different animal races one sex is absent, rare, or sterile, that sex is the heterozygous (heterogametic) sex', is one of the most general patterns in speciation biology. We review the literature of the past 15 years and find that among the similar to 85 new studies, many consider taxa that traditionally have not been the focus for HR investigations. The new studies increased to nine, the number of 'phylogenetically independent' groups that comply with HR. They continue to support the dominance and faster-male theories as explanations for HR, although due to increased reliance on indirect data (from, for example, differential introgression of cytoplasmic versus chromosomal loci in natural hybrid zones) unambiguous novel results are rare. We further highlight how research on organisms with sex determination systems different from those traditionally considered may lead to more insight in the underlying causes of HR. In particular, haplodiploid organisms provide opportunities for testing specific predictions of the dominance and faster X chromosome theory, and we present new data that show that the faster-male component of HR is supported in hermaphrodites, suggesting that genes involved in male function may evolve faster than those expressed in the female function. Heredity (2011) 107, 95-102; doi:10.1038/hdy.2010.170; published online 12 January 201
Identification of BRCA1 missense substitutions that confer partial functional activity: potential moderate risk variants?
Introduction: Many of the DNA sequence variants identified in the breast cancer susceptibility gene BRCA1 remain unclassified in terms of their potential pathogenicity. Both multifactorial likelihood analysis and functional approaches have been proposed as a means to elucidate likely clinical significance of such variants, but analysis of the comparative value of these methods for classifying all sequence variants has been limited. Methods: We have compared the results from multifactorial likelihood analysis with those from several functional analyses for the four BRCA1 sequence variants A1708E, G1738R, R1699Q, and A1708V. Results: Our results show that multifactorial likelihood analysis, which incorporates sequence conservation, co-inheritance, segregation, and tumour immunohistochemical analysis, may improve classification of variants. For A1708E, previously shown to be functionally compromised, analysis of oestrogen receptor, cytokeratin 5/6, and cytokeratin 14 tumour expression data significantly strengthened the prediction of pathogenicity, giving a posterior probability of pathogenicity of 99%. For G1738R, shown to be functionally defective in this study, immunohistochemistry analysis confirmed previous findings of inconsistent 'BRCA1-like' phenotypes for the two tumours studied, and the posterior probability for this variant was 96%. The posterior probabilities of R1699Q and A1708V were 54% and 69%, respectively, only moderately suggestive of increased risk. Interestingly, results from functional analyses suggest that both of these variants have only partial functional activity. R1699Q was defective in foci formation in response to DNA damage and displayed intermediate transcriptional transactivation activity but showed no evidence for centrosome amplification. In contrast, A1708V displayed an intermediate transcriptional transactivation activity and a normal foci formation response in response to DNA damage but induced centrosome amplification. Conclusion: These data highlight the need for a range of functional studies to be performed in order to identify variants with partially compromised function. The results also raise the possibility that A1708V and R1699Q may be associated with a low or moderate risk of cancer. While data pooling strategies may provide more information for multifactorial analysis to improve the interpretation of the clinical significance of these variants, it is likely that the development of current multifactorial likelihood approaches and the consideration of alternative statistical approaches will be needed to determine whether these individually rare variants do confer a low or moderate risk of breast cancer
Recognition of Depression in Older Medical Inpatients
BACKGROUND: Studies of recognition of depression in older (aged 65 or more) medical inpatients show low rates of recognition of depression by attending physicians. However, few studies have compared different measures of recognition of depression. OBJECTIVES: (1) To compare the validity of four indicators of recognition of depression and a global measure of recognition against a diagnosis of depression and (2) to explore the effect of patient characteristics on recognition of depression. METHODS: In a cohort of 264 medical inpatients 65 years and older (115 with major or minor depression, 78 with no depression), sensitivities, specificities, and diagnostic odds ratios (DOR) of 4 indicators of recognition (symptoms, diagnosis, treatment, and referral) and a global measure of recognition (any of the 4 indicators) were calculated. The associations between patient characteristics (age, sex, history of depression, antidepressant use before admission, severity of depression, comorbidity, duration of hospitalization, disability, and hospital of admission) and recognition were explored using multiple logistic regression. RESULTS: Less than half of the depressed patients were recognized. The indicator with the highest sensitivity was treatment (27.8%, 95% confidence interval [CI] 20.0–37.0), whereas the indicator with the best specificity was diagnosis (96.6%, 95% CI 91.9–98.7). The unadjusted DOR of global recognition was 2.6 (95% CI 1.5, 4.4). Less comorbidity, more severe depression symptoms, a history of depression, longer hospital stay, and antidepressant use before admission were significantly associated with better global recognition. CONCLUSION: Recognition of depression in elderly medical inpatients depends upon the indicator of recognition used
Rapid SNP Discovery and Genetic Mapping Using Sequenced RAD Markers
Single nucleotide polymorphism (SNP) discovery and genotyping are essential to genetic mapping. There remains a need for a simple, inexpensive platform that allows high-density SNP discovery and genotyping in large populations. Here we describe the sequencing of restriction-site associated DNA (RAD) tags, which identified more than 13,000 SNPs, and mapped three traits in two model organisms, using less than half the capacity of one Illumina sequencing run. We demonstrated that different marker densities can be attained by choice of restriction enzyme. Furthermore, we developed a barcoding system for sample multiplexing and fine mapped the genetic basis of lateral plate armor loss in threespine stickleback by identifying recombinant breakpoints in F2 individuals. Barcoding also facilitated mapping of a second trait, a reduction of pelvic structure, by in silico re-sorting of individuals. To further demonstrate the ease of the RAD sequencing approach we identified polymorphic markers and mapped an induced mutation in Neurospora crassa. Sequencing of RAD markers is an integrated platform for SNP discovery and genotyping. This approach should be widely applicable to genetic mapping in a variety of organisms
Complex Deleterious Interactions Associated with Malic Enzyme May Contribute to Reproductive Isolation in the Copepod Tigriopus californicus
Dobzhansky-Muller incompatibilities can result from the interactions of more than a single pair of interacting genes and there are several different models of how such complex interactions can be structured. Previous empirical work has identified complex conspecific epistasis as a form of complex interaction that has contributed to postzygotic reproductive isolation between taxa, but other forms of complexity are also possible. Here, I probe the genetic basis of reproductive isolation in crosses of the intertidal copepod Tigriopus californicus by looking at the impact of markers in genes encoding metabolic enzymes in F2 hybrids. The region of the genome associated with the locus ME2 is shown to have strong, repeatable impacts on the fitness of hybrids in crosses and epistatic interactions with another chromosomal region marked by the GOT2 locus in one set of crosses. In a cross between one of these populations and a third population, these two regions do not appear to interact despite the continuation of a large effect of the ME2 region itself in both crosses. The combined results suggest that the ME2 chromosomal region is involved in incompatibilities with several unique partners. If these deleterious interactions all stem from the same factor in this region, that would suggest a different form of complexity from complex conspecific epistasis, namely, multiple independent deleterious interactions stemming from the same factor. Confirmation of this idea will require more fine-scale mapping of the interactions of the ME2 region of the genome
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