The Spectral Geometry of Flat Disks

Mathematic

Contrasting sexual selection on males and females in a role-reversed swarming dance-fly, Rhamphomyia longicauda Loew (Diptera: Empididae)

Sex-specific ornamentation is widely known among male animals, but even among sex-role reversed species, ornamented females are rare. Although several hypotheses for this pattern exist, too few systems featuring female ornaments have been studied in detail to adequately test them. Empidine dance flies are exceptional in that many species show female ornamentation of wings, abdomens, or legs. Here we compare sexual selection in males and females of the long-tailed dance fly, Rhamphomyia longicauda Loew (Diptera: Empididae), a sex-role reversed fly in which swarming females aggregate in competition for the nuptial gifts provided by males during mating. Females in this species possess several secondary sex characters, including eversible abdominal sacs, enlarged wings, and decorated tibiae that may all function in mate attraction during swarming. Males preferentially approach large females in the swarm, but the strength and shape of selection on females and the degree to which selection is sex-specific are unknown. We estimated linear and nonlinear sexual selection on structures expressed in both male and female flies, and found contrasting patterns of sexual selection on wing length and tibia length in males and females. In females, long wings and short tibiae were associated with mating success, whereas selection on males was significantly different: males with short wings and long tibiae were most likely to mate (although tibia length was a marginally non-significant predictor of male mating success). We found no evidence for assortative or disassortative mating. Although the largest females occupied positions within the swarm closest to the entry point for choosy males, in contrast to selection for mating success these females tended to have larger tibiae than rivals. We discuss our findings in the context of the mating biology of R. longicauda compared to other empidine dance flies, and its relevance to the evolution of sexual dimorphism in general

The spin-wave spectrum of the Jahn-Teller system LaTiO3

We present an analytical calculation of the spin-wave spectrum of the Jahn-Teller system LaTiO3. The calculation includes all superexchange couplings between nearest-neighbor Ti ions allowed by the space-group symmetries: The isotropic Heisenberg couplings and the antisymmetric (Dzyaloshinskii-Moriya) and symmetric anisotropies. The calculated spin-wave dispersion has four branches, two nearly degenerate branches with small zone-center gaps and two practically indistinguishable high-energy branches having large zone-center gaps. The two lower-energy modes are found to be in satisfying agreement with neutron-scattering experiments. In particular, the experimentally detected approximate isotropy in the Brillouin zone and the small zone-center gap are well reproduced by the calculations. The higher-energy branches have not been detected yet by neutron scattering but their zone-center gaps are in satisfying agreement with recent Raman data.Comment: 13 pages, 5 figure

A preliminary audit of medical and aid provision in English Rugby union clubs:compliance with Regulation 9

BackgroundGoverning bodies are largely responsible for the monitoring and management of risks associated with a safe playing environment, yet adherence to regulations is currently unknown. The aim of this study was to investigate and evaluate the current status of medical personnel, facilities, and equipment in Rugby Union clubs at regional level in England.MethodsA nationwide cross-sectional survey of 242 registered clubs was undertaken, where clubs were surveyed online on their current medical personnel, facilities, and equipment provision, according to regulation 9 of the Rugby Football Union (RFU).ResultsOverall, 91 (45. 04%) surveys were returned from the successfully contacted recipients. Of the completed responses, only 23.61% (n = 17) were found to be compliant with regulations. Furthermore, 30.56% (n = 22) of clubs were unsure if their medical personnel had required qualifications; thus, compliance could not be determined. There was a significant correlation (p = −0.029, r = 0.295) between club level and numbers of practitioners. There was no significant correlation indicated between the number of practitioners/number of teams and number of practitioners/number of players. There were significant correlations found between club level and equipment score (p = 0.003, r = −0.410), club level and automated external defibrillator (AED) access (p = 0.002, r = −0.352) and practitioner level and AED access (p = 0.0001, r = 0.404). Follow-up, thematic analysis highlighted widespread club concern around funding/cost, awareness, availability of practitioners and AED training.ConclusionThe proportion of clubs not adhering overall compliance with Regulation 9 of the RFU is concerning for player welfare, and an overhaul, nationally, is required

Alteration of Gene Expression Signatures of Cortical Differentiation and Wound Response in Lethal Clear Cell Renal Cell Carcinomas

Clear cell renal cell carcinoma (ccRCC) is the most common malignancy of the adult kidney and displays heterogeneity in clinical outcomes. Through comprehensive gene expression profiling, we have identified previously a set of transcripts that predict survival following nephrectomy independent of tumor stage, grade, and performance status. These transcripts, designated as the SPC (supervised principal components) gene set, show no apparent biological or genetic features that provide insight into renal carcinogenesis or tumor progression. We explored the relationship of this gene list to a set of genes expressed in different anatomical segments of the normal kidney including the cortex (cortex gene set) and the glomerulus (glomerulus gene set), and a gene set expressed after serum stimulation of quiescent fibroblasts (the core serum response or CSR gene set). Interestingly, the normal cortex, glomerulus (part of the normal renal cortex), and CSR gene sets captured more than 1/5 of the genes in the highly prognostic SPC gene set. Based on gene expression patterns alone, the SPC gene set could be used to sort samples from normal adult kidneys by the anatomical regions from which they were dissected. Tumors whose gene expression profiles most resembled the normal renal cortex or glomerulus showed better survival than those that did not, and those with expression features more similar to CSR showed poorer survival. While the cortex, glomerulus, and CSR signatures predicted survival independent of traditional clinical parameters, they were not independent of the SPC gene list. Our findings suggest that critical biological features of lethal ccRCC include loss of normal cortical differentiation and activation of programs associated with wound healing

A Public-Domain Personality Item Bank For Use With The Raymark, Schmit, and Guion (1997) PPRF

Presented is the development of a repository of work-related personality items that may be used to assess job-related traits identified by the Personality-Related Position Requirements Form (PPRF: Raymark, Schmit, & Guion, 1997). Analyses of the item pool administered to a sample (n = 412) of trade apprentices showed evidence to support the12 work-related Big 5 sub-dimensions identified by the PPRF. A smaller validity study (n = 47) suggested that personality dimensions identified as job-related by the PPRF were related to important job-related outcomes

Non-O157 Shiga Toxin–Producing \u3ci\u3eEscherichia coli\u3c/i\u3e Infections in the United States, 1983–2002

Background. Shiga toxin–producing Escherichia coli (STEC) O157:H7 is a well-recognized cause of bloody diarrhea and hemolytic-uremic syndrome (HUS). Non-O157 STEC contribute to this burden of illness but have been underrecognized as a result of diagnostic limitations and inadequate surveillance. Methods. Between 1983 and 2002, 43 state public health laboratories submitted 940 human non-O157 STEC isolates from persons with sporadic illnesses to the Centers for Diseases Control and Prevention reference laboratory for confirmation and serotyping. Results. The most common serogroups were O26 (22%), O111 (16%), O103 (12%), O121 (8%), O45 (7%), and O145 (5%). Non-O157 STEC infections were most frequent during the summer and among young persons (median age, 12 years; interquartile range, 3–37 years). Virulence gene profiles were as follows: 61% stx1 but not stx2; 22% stx2 but not stx1; 17% both stx1 and stx2; 84% intimin (eae); and 86% enterohemolysin (E-hly). stx2 was strongly associated with an increased risk of HUS, and eae was strongly associated with an increased risk of bloody diarrhea. STEC O111 accounted for most cases of HUS and was also the cause of 3 of 7 non-O157 STEC outbreaks reported in the United States. Conclusions. Non-O157 STEC can cause severe illness that is comparable to the illness caused by STEC O157. Strains that produce Shiga toxin 2 are much more likely to cause HUS than are those that produce Shiga toxin 1 alone. Improving surveillance will more fully elucidate the incidence and pathological spectrum of these emerging agents. These efforts require increased clinical suspicion, improved clinical laboratory isolation, and continued serotyping of isolates in public health laboratories