Discovery of meteorites on a blue-ice field near the Frontier Mountains, North Victoria Land, Antarctica

A high concentration of meteorites were discovered on a blue ice field northeast of the Frontier Mountains. As a result of a systematic search, a total of 42 meteorites were recovered. The current glacial situation has evolved through various stages, which are discussed in relationship to the concentration of meteorites. Ice flow patterns are summarized. The chemical composition and terrestrial ages of the meteorites are discussed

Chemical and Toxicological Characterization of the Upper York River, Virginia The Mattaponi and Pamunkey Rivers

This study describes the most extensive effort to characterize the chemistry, toxicology and community of the sediments of the Mattaponi and Pamunkey Rivers. This was accomplished using a study design modified to expand the number of stations occupied by reducing the cost of analyses by compositing replicate samples collected from each study site rather than performing toxicity tests on these samples individually. In previous studies, the variability in field replicate samples was equivalent to the variability in laboratory replicates. This design has long been used to analyze samples for various chemical contaminants as a cost savings endeavor. More ...

At-risk serum cholesterol profile at both ends of the nutrition spectrum in West African adults? The Benin study

Low HDL-cholesterol (HDL-C), using as cut-offs 1.03 mmol/L in men and 1.29 mmol/L in women, was observed in more than 25% apparently healthy adults (n = 541) in a cross-sectional study on nutrition transition and cardiometabolic risk factors (CMRF) in Benin, West Africa. Both overweight/obesity (35.3%) and underweight (11.3%) were present, displaying the double burden of malnutrition. We examined in more depth the association of low HDL-C with nutrition and with other CMRF. Metabolic syndrome components were assessed, plus the ratio of total cholesterol (TC)/HDL-C and serum homocysteine. Insulin resistance was based on Homeostasis Model Assessment. We also measured BMI and body composition by bio-impedance. Dietary quality was appraised with two non-consecutive 24 h recalls. Low HDL-C was associated with much higher TC/HDL-C and more abdominal obesity in men and women and with more insulin resistance in women. The rate of low HDL-C was highest (41.9%) among the overweight/obese subjects (BMI ≥ 25), but it also reached 31.1% among the underweight (BMI < 18.5), compared with 17.3% among normal-weight subjects (p < 0.001). Lower dietary micronutrient adequacy, in particular, in vitamins A, B3, B12, zinc and calcium, was associated with low HDL-C when controlling for several confounders. This suggests that at-risk lipoprotein cholesterol may be associated with either underweight or overweight/obesity and with poor micronutrient intake

Chemical and toxicological characterization of the lower Mobjack Bay, York River, Virginia segment of the Chesapeake Bay

The Chesapeake Bay segment called Lower Mobjack Bay Lower York River Virginia was found to have insufficient data to characterize in 1999. Therefore this area was selected for a chemical, toxicological, benthic community characterization study of the sediments in 2002. The segment was divided into 3 strata: the lower York River, the Poquoson River, and Back River, each with 4 randomly selected stations. Samples were collected in October 2002 for evaluation of conditions. There were few significant chemical exceedances of the ER-L or ER-M in the three strata and no toxicologically effects from exposure to sediment samples from any stratum. In contrast, the Poquoson and Back River strata showed consistent community degradation ranging from degraded to seriously degraded. The lack of chemical and toxicological impacts and the intensive residential land use makes it reasonable to conclude that the likely explanation for the degraded benthic community is eutrophication. There is not, however, confirmatory data for this interpretation

Transient and Dynamic Average-Value Modeling of Synchronous Machine Fed Load-Commutated Converters

A new average-value model of a synchronous machine fed load-commutated converter is set forth in which the stator dynamics are combined with the DC link dynamics. This model is shown to he extremely accurate in predicting system transients and in predicting frequency-domain characteristics such as the impedance looking into the synchronous machine fed load-commutated converter. The model is verified against a detailed computer simulation and against a hardware test system, thus providing a three-way comparison. The proposed model is shown to be much more accurate than models in which the stator dynamics are neglecte

Nematicity as a route to a magnetic field-induced spin density wave order; application to the high temperature cuprates

The electronic nematic order characterized by broken rotational symmetry has been suggested to play an important role in the phase diagram of the high temperature cuprates. We study the interplay between the electronic nematic order and a spin density wave order in the presence of a magnetic field. We show that a cooperation of the nematicity and the magnetic field induces a finite coupling between the spin density wave and spin-triplet staggered flux orders. As a consequence of such a coupling, the magnon gap decreases as the magnetic field increases, and it eventually condenses beyond a critical magnetic field leading to a field-induced spin density wave order. Both commensurate and incommensurate orders are studied, and the experimental implications of our findings are discussed.Comment: 5 pages, 3 figure

Prédiction de l’insulino-résistance par les ratios de lipoprotéines chez les adultes béninois

Des controverses subsistent sur force prédictive de l’insulino-résistance par les ratios de lipoprotéines chez les Afro-américains. L’objectif est de déterminer la force prédictive de l’insulino-résistance (IR) par les ratios triglycérides-par-HDL-cholestérol (TG/HDL-C) et cholestérol total-par-HDL-cholestérol (CT/HDL-C) chez des adultes béninois. L’étude est de type transversal, issue d’une enquête longitudinale sur le risque cardiométabolique et a inclut 416 sujets âgés de 29 à 69 ans. Les mesures anthropométriques et les dosages de la glycémie à jeun, de l’insulinémie, du CT, du HDL-C et des TG sont réalisés. L’IR est définie par le 75ème percentile des valeurs de « l’indice d’évaluation de modèle d'homéostasie pour l’insulino-résistance» (HOMA IR). Les valeurs prédictives de l’IR par les ratios TG/HDL-C et CT/HDL-C sont déterminées par les aires sous les courbes (AUC) de la « fonction d’efficacité du récepteur» (ROC). Les concentrations plasmatiques moyennes des lipides ont été en général plus élevées chez les IR que chez les non IR sauf pour les triglycérides : 0,9±0,5 mmol/L versus 0,8±0,4 mmol/L (p=0,138) chez les femmes, le cholestérol total : 4,7±1,7 mmol/L versus 4,3±1,2 mmol/L (p=0,161) et le HDL-Cholestérol : 1,2±0,5 mmol/L versus 1,34±0,5 mmol/L (p=0,105) chez les hommes. Les AUC ROC de prédiction de l’IR par le TG/HDL-C sont inférieures à 0,70 chez les femmes et les hommes, les obèses et les non obèses. L’AUC ROC de prédiction de l’IR par le CT/HDL-C est supérieure à 0,70 seulement chez les femmes : 0,71 (0,64-0,78). Le ratio TG/HDL-C n’est pas un prédicteur de l’IR dans la population d’étude alors que le ratio CT/HDL-C prédit l’IR chez les femmes seulement. Ces résultats contribueront au dépistage précoce de l’IR chez les femmes aux fins de la mise en place de mesures préventives.Mots clés : Prédiction, insulino-résistance, lipoprotéines, dyslipidémies, Bénin

Preliminary Survey of the Algae of Lake Ahquabi

Forty-one genera of algae are reported from Lake Ahquabi, Warren County, Iowa. The most commonly occurring genera are Cladophora, Spirogyra, Hydrodictyon, Microcystis, Oscillatoria and Aphanizomenon. The latter three contribute to extensive blooms on the lake in late summer and fall