809 research outputs found

    Eyes in the dark ... Shedding light on the antlion phylogeny and the enigmatic genus Pseudimares Kimmins (Neuropterida: Neuroptera: Myrmeleontidae)

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    The systematic position of the antlion Pseudimares Kimmins has been disputed since description of the genus. Pseudimares is one of the most enigmatic and unusual members of Myrmeleontidae and probably of all Neuroptera. The taxon has been usually tied to the antlion subfamily Palparinae, although its phylogenetic affinities have never been thoroughly investigated and the monophyly of the subfamily as a whole has never been corroborated. We reconstruct for the first time the phylogenetic affinities of Pseudimares based on both morphological and molecular genetic data. The widely accepted subfamily level subdivision of antlions (Stilbopteryginae, Palparinae, Myrmeleontinae) is refuted in all our analyses, since Stilbopteryginae in the traditional sense are recovered as deeply nested within Myrmeleontidae forming a monophylum with Palparinae, while Myrmeleontinae are poorly supported by the parsimony analysis. In our morphology-based parsimony analysis, Pseudimares is the sister taxon of Stilbopteryx and Aeropteryx, which makes the traditional Palparinae paraphyletic. This result is further supported by our phylogenetic reconstruction based on molecular data, which found a clade including Pseudimares and Stilbopteryx, which is nested within the traditional Palparinae. The high genetic distances measured among the analysed taxa suggest that these groups quickly diverged in ancient times, although they remained morphologically homogeneous. In conformity with the results of the phylogenetic analyses, we propose a new classification scheme for antlions, one that merges Stilbopteryx and Aeropteryx into an expanded concept of the subfamily Palparinae

    VLT Diffraction Limited Imaging and Spectroscopy in the NIR: Weighing the black hole in Centaurus A with NACO

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    We present high spatial resolution near-infrared spectra and images of the nucleus of Centaurus A (NGC 5128) obtained with NAOS-CONICA at the VLT. The adaptive optics corrected data have a spatial resolution of 0.06" (FWHM) in K- and 0.11" in H-band, four times higher than previous studies. The observed gas motions suggest a kinematically hot disk which is orbiting a central object and is oriented nearly perpendicular to the nuclear jet. We model the central rotation and velocity dispersion curves of the [FeII] gas orbiting in the combined potential of the stellar mass and the (dominant) black hole. Our physically most plausible model, a dynamically hot and geometrically thin gas disk, yields a black hole mass of M_bh = (6.1 +0.6/-0.8) 10^7 M_sun. As the physical state of the gas is not well understood, we also consider two limiting cases: first a cold disk model, which completely neglects the velocity dispersion; it yields an M_bh estimate that is almost two times lower. The other extreme case is to model a spherical gas distribution in hydrostatic equilibrium through Jeans equation. Compared to the hot disk model the best-fit black hole mass increases by a factor of 1.5. This wide mass range spanned by the limiting cases shows how important the gas physics is even for high resolution data. Our overall best-fitting black hole mass is a factor of 2-4 lower than previous measurements. With our revised M_bh estimate, Cen A's offset from the M_bh-sigma relation is significantly reduced; it falls above this relation by a factor of ~2, which is close to the intrinsic scatter of this relation. (Abridged)Comment: 12 pages, 14 figures, including minor changes following the referee report; accepted for publication in The Astrophysical Journa

    Time-resolved broadband analysis of slow-light propagation and superluminal transmission of electromagnetic waves in three-dimensional photonic crystals

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    A time-resolved analysis of the amplitude and phase of THz pulses propagating through three-dimensional photonic crystals is presented. Single-cycle pulses of THz radiation allow measurements over a wide frequency range, spanning more than an octave below, at and above the bandgap of strongly dispersive photonic crystals. Transmission data provide evidence for slow group velocities at the photonic band edges and for superluminal transmission at frequencies in the gap. Our experimental results are in good agreement with finite-difference-time-domain simulations.Comment: 7 pages, 11 figure

    Diagnosis of hepatocellular adenoma in men before onset of diabetes in HNF1A-MODY:Watch out for winkers

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    Hepatocyte nuclear factor 1A (HNF1A) maturity-onset diabetes of the young (MODY) is a monogenetic, autosomal dominantly inherited form of diabetes. HNF1A-MODY is associated with HNF1A-inactivated hepatocellular adenoma (H-HCA) formation. Hepatocellular adenoma (HCA) are benign liver tumours and related complications are rare but serious: hepatic haemorrhage and malignant transformation. Guidelines recommend resection of all HCA in men and do not take any co-occurring metabolic disorders into account. We report a family with HCA preceding diabetes mellitus. Male index patient presented with numerous, irresectable HCA. After initial diagnostic and aetiologic uncertainty HNF1A germline mutation c.815G>A (p.Arg272His) was confirmed 8 years later. No HCA-related complications occurred. His diabetic mother was diagnosed with HCA after severe hepatic haemorrhage years before. HNF1A-MODY should be considered in (non-)diabetic (male) patients with H-HCA. We advocate liver biopsy and, if necessary, genetic analysis to precede any intervention for HCA in males and screening for HCA in HNF1A-MODY patients

    A SULT2A1 genetic variant identified by GWAS as associated with low serum DHEAS does not impact on the actual DHEA/DHEAS ratio

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    DHEA is the major precursor of human sex steroid synthesis and is inactivated via sulfonation to DHEAS. A previous genome-wide association study related the single nucleotide polymorphism (SNP) rs2637125, located near the coding region of DHEA sulfotransferase, SULT2A1, to serum DHEAS concentrations. However, the functional relevance of this SNP with regard to DHEA sulfonation is unknown. Using data from 3300 participants of the population-based cohort Study of Health in Pomerania, we identified 43 individuals being homozygote for the minor allele of the SNP rs2637125 (AA) and selected two sex- and age-matched individuals with AG and GG genotype (n=172) respectively. Steroid analysis including measurement of serum DHEA and DHEAS was carried out by liquid chromatography/mass spectrometry, employing steroid oxime analysis for enhancing the sensitivity of DHEA detection. We applied quantile regression models to compare median hormone levels across SULT2A1 genotypes. Median comparisons by SULT2A1 genotype (AA vs AG and GG genotypes respectively) showed no differences in the considered hormones including DHEAS, DHEA, androstenedione, as well as cortisol and cortisone concentrations. SULT2A1 genotype also had no effect on the DHEA/DHEAS ratio. Sex-stratified analyses, as well as alternative use of the SULT2A1 SNP rs182420, yielded similar negative results. Genetic variants of SULT2A1 do not appear to have an effect on individual DHEA and DHEAS concentrations or the DHEA/DHEAS ratio as a marker of DHEA sulfonation capacity

    The influence of calcium and magnesium in drinking water and diet on cardiovascular risk factors in individuals living in hard and soft water areas with differences in cardiovascular mortality

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    BACKGROUND: The role of water hardness as a risk factor for cardiovascular disease has been widely investigated and evaluated as regards regional differences in cardiovascular disease. This study was performed to evaluate the relation between calcium and magnesium in drinking water and diet and risk factors for cardiovascular disease in individuals living in hard and soft water areas with considerable differences in cardiovascular mortality. METHODS: A random sample of 207 individuals living in two municipalities characterised by differences in cardiovascular mortality and water hardness was invited for an examination including a questionnaire about health, social and living conditions and diet. Intake of magnesium and calcium was calculated from the diet questionnaire with special consideration to the use of local water. Household water samples were delivered by each individual and were analysed for magnesium and calcium. RESULTS: In the total sample, there were positive correlations between the calcium content in household water and systolic blood pressure (SBP) and negative correlations with s-cholesterol and s-LDL-cholesterol. No correlation was seen with magnesium content in household water to any of the risk factors. Calcium content in diet showed no correlation to cardiovascular risk factors. Magnesium in diet was positively correlated to diastolic blood pressure (DBP). In regression analyses controlled for age and sex 18.5% of the variation in SBP was explained by the variation in BMI, HbA1c and calcium content in water. Some 27.9% of the variation in s-cholesterol could be explained by the variation in s-triglycerides (TG), and calcium content in water. CONCLUSIONS: This study of individuals living in soft and hard water areas showed significant correlations between the content of calcium in water and major cardiovascular risk factors. This was not found for magnesium in water or calcium or magnesium in diet. Regression analyses indicated that calcium content in water could be a factor in the complexity of relationships and importance of cardiovascular risk factors. From these results it is not possible to conclude any definite causal relation and further research is needed

    Разработка основного оборудования получения металлического лития

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    Объектом исследования является выпарной аппарат установки получения металлического лития, находящейся в ОАО "НЗХК" (Новосибирский завод химконцентратов). Целью работы были проектирование и исследование выпарного аппарата с центральной циркуляционной трубой и подвесной греющей камерой. Преимущества аппарата с подвесной греющей камерой. Для достижения поставленной цели были решены следующие задачи: анализ конструкций аппаратов; произведен конструктивный и механический расчеты; сравнение полученных расчетов.The object of study is evaporating apparatus unit for production of lithium metal located in the Novosibirsk chemical concentrates plant (Novosibirsk chemical concentrates plant). The aim of this work was the design and study of evaporator with the Central circulation pipe and the suspended heating chamber. The advantages of the apparatus with overhead heating chamber. To achieve this goal have been resolved following tasks: analysis of equipment designs; produced structural and mechanical calculations; comparison of the calculations

    Бухгалтерский учет расчетов с персоналом по оплате труда (на примере предприятия HORUS INTERTRADE & CONSULTING)

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    В данной работе была рассмотрена специфика бухгалтерского учета расчетов с персоналом по оплате труда как в соответствии с российским законодательством, так и с законодательством Республики Узбекистан, дана характеристика организации бухгалтерского учета операций по расчетам с персоналом в узбекской компании ООО "Horus Intertrade & Consulting Kft", предложены меры по ее совершенствованию.In this work, the specifics of the bookkeeping of settlements with employees on remuneration of labor, both in accordance with Russian legislation and with the legislation of the Republic of Uzbekistan, was given, and the characteristics of the organization of accounting for transactions with personnel in the Uzbek company Horus Intertrade & Consulting Kft, Measures for its improvement have been proposed
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