867 research outputs found

    Efficacy of Morphological Characters for Distinguishing Nymphs of \u3ci\u3eEpitheca Cynosura\u3c/i\u3e and \u3ci\u3eEpitheca Spinigera\u3c/i\u3e (Odonata: Corduliidae) in Wisconsin

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    Attempts to distinguish exuviae and last-instar nymphs of Epitheca cynosura (Say) and Epitheca spinigera (Selys) (Odonata: Corduliidae) using lateral spine characters have proven to be unreliable, and recent use of setae counts on only one side of the prementum or one labial palp have led to confusion because these structures often hold unequal numbers of setae on the two sides of the same specimen. Based on exuviae of 67 reared E. cynosura and 55 reared E. spinigera from lakes throughout Wisconsin, we tested the efficacy of previously used character states for distinguishing these species and searched for new characters to improve the reliability of regional keys. The most reliable diagnostic character was the combined number of setae on both sides of the prementum and on both labial palps (≤ 35 – E. cynosura; ≥ 36 – E. spinigera), which correctly determined 96% of our specimens. For the small percentage of specimens that lie in the region of overlap in total setae number, we found that total exuviae length, cerci ÷ epiproct ratios of females, tubercle distance ÷ epiproct ratios of males, and the shape of the dorsal hook on segment 8 could be used to strengthen determinations

    Efficacy of Morphological Characters for Distinguishing Nymphs of \u3ci\u3eEpitheca Cynosura\u3c/i\u3e and \u3ci\u3eEpitheca Spinigera\u3c/i\u3e (Odonata: Corduliidae) in Wisconsin

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    Attempts to distinguish exuviae and last-instar nymphs of Epitheca cynosura (Say) and Epitheca spinigera (Selys) (Odonata: Corduliidae) using lateral spine characters have proven to be unreliable, and recent use of setae counts on only one side of the prementum or one labial palp have led to confusion because these structures often hold unequal numbers of setae on the two sides of the same specimen. Based on exuviae of 67 reared E. cynosura and 55 reared E. spinigera from lakes throughout Wisconsin, we tested the efficacy of previously used character states for distinguishing these species and searched for new characters to improve the reliability of regional keys. The most reliable diagnostic character was the combined number of setae on both sides of the prementum and on both labial palps (≤ 35 – E. cynosura; ≥ 36 – E. spinigera), which correctly determined 96% of our specimens. For the small percentage of specimens that lie in the region of overlap in total setae number, we found that total exuviae length, cerci ÷ epiproct ratios of females, tubercle distance ÷ epiproct ratios of males, and the shape of the dorsal hook on segment 8 could be used to strengthen determinations

    Plastid osmotic stress influences cell differentiation at the plant shoot apex

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    The balance between proliferation and differentiation in the plant shoot apical meristem is controlled by regulatory loops involving the phytohormone cytokinin and stem cell identity genes. Concurrently, cellular differentiation in the developing shoot is coordinated with the environmental and developmental status of plastids within those cells. Here, we employ an Arabidopsis thaliana mutant exhibiting constitutive plastid osmotic stress to investigate the molecular and genetic pathways connecting plastid osmotic stress with cell differentiation at the shoot apex. msl2 msl3 mutants exhibit dramatically enlarged and deformed plastids in the shoot apical meristem, and develop a mass of callus tissue at the shoot apex. Callus production in this mutant requires the cytokinin receptor AHK2 and is characterized by increased cytokinin levels, downregulation of cytokinin signaling inhibitors ARR7 and ARR15, and induction of the stem cell identity gene WUSCHEL. Furthermore, plastid stress-induced apical callus production requires elevated plastidic reactive oxygen species, ABA biosynthesis, the retrograde signaling protein GUN1, and ABI4. These results are consistent with a model wherein the cytokinin/WUS pathway and retrograde signaling control cell differentiation at the shoot apex

    Decision-making capacity for treatment in psychiatric and medical in-patients: Cross-sectional, comparative study

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    BackgroundIs the nature of decision-making capacity (DMC) for treatment significantly different in medical and psychiatric patients?AimsTo compare the abilities relevant to DMC for treatment in medical and psychiatric patients who are able to communicate a treatment choice.MethodA secondary analysis of two cross-sectional studies of consecutive admissions: 125 to a psychiatric hospital and 164 to a medical hospital. The MacArthur Competence Assessment Tool – Treatment and a clinical interview were used to assess decision-making abilities (understanding, appreciating and reasoning) and judgements of DMC. We limited analysis to patients able to express a choice about treatment and stratified the analysis by low and high understanding ability.ResultsMost people scoring low on understanding were judged to lack DMC and there was no difference by hospital (P=0.14). In both hospitals there were patients who were able to understand yet lacked DMC (39% psychiatric v. 13% medical in-patients, P&lt;0.001). Appreciation was a better ‘test’ of DMC in the psychiatric hospital (where psychotic and severe affective disorders predominated) (P&lt;0.001), whereas reasoning was a better test of DMC in the medical hospital (where cognitive impairment was common) (P=0.02).ConclusionsAmong those with good understanding, the appreciation ability had more salience to DMC for treatment in a psychiatric setting and the reasoning ability had more salience in a medical setting.</jats:sec

    Comparative sequence analysis and tissue localization of members of the SLC6 family of transporters in adult Drosophila melanogaster

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    SUMMARY The SLC6 family comprises proteins that move extracellular neurotransmitters, amino acids and osmolytes across the plasma membrane into the cytosol. In mammals, deletion of SLC6 family members has dramatic physiologic consequences, but in the model organism Drosophila melanogaster, little is known about this family of proteins. Therefore, in this study we carried out an initial analysis of 21 known or putative SLC6 family members from the Drosophila genome. Protein sequences from these genes segregated into either well-defined subfamilies, including the novel insect amino acid transporter subfamily, or into a group of weakly related sequences not affiliated with a recognized subfamily. Reverse transcription-polymerase chain reaction analysis and in situ hybridization showed that seven of these genes are expressed in the CNS. In situ hybridization revealed that two previously cloned SLC6 members, the serotonin and dopamine transporters, were localized to presumptive presynaptic neurons that previously immunolabelled for these transmitters. RNA for CG1732 (the putative GABA transporter) and CG15088 (a member of the novel insect amino acid transporter family) was localized in cells likely to be subtypes of glia, while RNA for CG5226, CG10804 (both members of the orphan neurotransmitter transporter subfamily) and CG5549 (a putative glycine transporter) were expressed broadly throughout the cellular cortex of the CNS. Eight of the 21 sequences were localized outside the CNS in the alimentary canal, Malpighian tubules and reproductive organs. Localization for six sequences was not found or not attempted in the adult fly. We used the Drosophila ortholog of the mammalian vesicular monoamine transporter 2, CG33528, to independently identify monoaminergic neurons in the adult fly. RNA for CG33528 was detected in a limited number of cells in the central brain and in a beaded stripe at the base of the photoreceptors in the position of glia, but not in the photoreceptors themselves. The SLC6 localization observations in conjunction with likely substrates based on phylogenetic inferences are a first step in defining the role of Na/Cl-dependent transporters in Drosophila physiology

    A Dense SNP-Based Linkage Map for Atlantic Salmon (Salmo salar) Reveals extended Chromosome Homeologies and Striking Differences in Sex-Specific Recombination Patterns

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    Background: The Atlantic salmon genome is in the process of returning to a diploid state after undergoing awhole genome duplication (WGD) event between 25 and100 million years ago. Existing data on the proportion ofparalogous sequence variants (PSVs), multisite variants (MSVs) and other types of complex sequence variationsuggest that the rediplodization phase is far from over. The aims of this study were to construct a high densitylinkage map for Atlantic salmon, to characterize the extent of rediploidization and to improve our understandingof genetic differences between sexes in this species.Results: A linkage map for Atlantic salmon comprising 29 chromosomes and 5650 single nucleotidepolymorphisms (SNPs) was constructed using genotyping data from 3297 fish belonging to 143 families. Of these,2696 SNPs were generated from ESTs or other gene associated sequences. Homeologous chromosomal regionswere identified through the mapping of duplicated SNPs and through the investigation of syntenic relationshipsbetween Atlantic salmon and the reference genome sequence of the threespine stickleback (Gasterosteusaculeatus). The sex-specific linkage maps spanned a total of 2402.3 cM in females and 1746.2 cM in males,highlighting a difference in sex specific recombination rate (1.38:1) which is much lower than previously reportedin Atlantic salmon. The sexes, however, displayed striking differences in the distribution of recombination siteswithin linkage groups, with males showing recombination strongly localized to telomeres.Conclusion: The map presented here represents a valuable resource for addressing important questions of interestto evolution (the process of re-diploidization), aquaculture and salmonid life history biology and not least as aresource to aid the assembly of the forthcoming Atlantic salmon reference genome sequence

    A linkage map of the Atlantic salmon (Salmo salar) based on EST-derived SNP markers

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    <p>Abstract</p> <p>Background</p> <p>The Atlantic salmon is a species of commercial and ecological significance. Like other salmonids, the species displays residual tetrasomy and a large difference in recombination rate between sexes. Linkage maps with full genome coverage, containing both type I and type II markers, are needed for progress in genomics. Furthermore, it is important to estimate levels of linkage disequilibrium (LD) in the species. In this study, we developed several hundred single nucleotide polymorphism (SNP) markers for the Atlantic salmon, and constructed male and female linkage maps containing SNP and microsatellite markers. We also investigated further the distribution of male and female recombination events across the genome, and estimated levels of LD between pairs of markers.</p> <p>Results</p> <p>The male map had 29 linkage groups and was 390 cM long. The female map had 30 linkage groups as was 1983 cM long. In total, the maps contained 138 microsatellite markers and 304 SNPs located within genes, most of which were successfully annotated. The ratio of male to female recombination events was either close to zero or very large, indicating that there is little overlap between regions in which male and female crossovers occur. The female map is likely to have close to full genome coverage, while the majority of male linkage groups probably lack markers in telomeric regions where male recombination events occur. Levels of r<sup>2 </sup>increased with decreasing inter-marker distance in a bimodal fashion; increasing slowly from ~60 cM, and more rapidly more from ~12 cM. Long-ranging LD may be consequence of recent admixture in the population, the population being a 'synthetic' breeding population with contributions from several distinct rivers. Levels of r<sup>2 </sup>dropped to half its maximum value (above baseline) within 15 cM, and were higher than 0.2 above baseline for unlinked markers ('useful LD') at inter-marker distances less than 5 cM.</p> <p>Conclusion</p> <p>The linkage map presented here is an important resource for genetic, comparative, and physical mapping of the Atlantic salmon. The female map is likely to have a map coverage that is not far from complete, whereas the male map length is likely to be significantly shorter than the true map, due to suboptimal marker coverage in the apparently small physical regions where male crossovers occur. 'Useful LD' was found at inter-marker distances less than 5 cM.</p

    Axion monodromy in a model of holographic gluodynamics

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    The low energy field theory for N type IIA D4-branes at strong 't Hooft coupling, wrapped on a circle with antiperiodic boundary conditions for fermions, is known to have a vacuum energy which depends on the θ\theta angle for the gauge fields, and which is a multivalued function of this angle. This gives a field-theoretic realization of "axion monodromy" for a nondynamical axion. We construct the supergravity solution dual to the field theory in the metastable state which is the adiabatic continuation of the vacuum to large values of θ\theta. We compute the energy of this state and show that it initially rises quadratically and then flattens out. We show that the glueball mass decreases with θ\theta, becoming much lower than the 5d KK scale governing the UV completion of this model. We construct two different classes of domain walls interpolating between adjacent vacua. We identify a number of instability modes -- nucleation of domain walls, bulk Casimir forces, and condensation of tachyonic winding modes in the bulk -- which indicate that the metastable branch eventually becomes unstable. Finally, we discuss two phenomena which can arise when the axion is dynamical; axion-driven inflation, and axion strings.Comment: 43 pages, 10 figures. v2: references update
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