The Dynamics Of Introgression Across An Avian Radiation

Hybridization and resulting introgression can play both a destructive and a creative role in the evolution of diversity. Thus, characterizing when and where introgression is most likely to occur can help us understand the causes of diversification dynamics. Here, we examine the prevalence of and variation in introgression using phylogenomic data from a large (1300+ species), geographically widespread avian group, the suboscine birds. We first examine patterns of gene tree discordance across the geographic distribution of the entire clade. We then evaluate the signal of introgression in a subset of 206 species triads using Patterson\u27s D-statistic and test for associations between introgression signal and evolutionary, geographic, and environmental variables. We find that gene tree discordance varies across lineages and geographic regions. The signal of introgression is highest in cases where species occur in close geographic proximity and in regions with more dynamic climates since the Pleistocene. Our results highlight the potential of phylogenomic datasets for examining broad patterns of hybridization and suggest that the degree of introgression between diverging lineages might be predictable based on the setting in which they occur

ANTIOXIDANT AND HEPATOPROTECTIVE EFFECT OF QUERCUS ILEX LEAVES EXTRACT IN ETHANOL INDUCED LIVER DAMAGE IN WISTAR RATS

Objective: This study was undertaken to investigate the hepatoprotective and antioxidant activity of Quercus ilex leaves extract (QILE) on ethanol-induced toxicity in Wistar rats. Methods: Hepatotoxicity was induced by administering ethanol (40%) at a dose of 7.9 gm/kg/day; p. o. (1:1 of ethanol in olive oil) for 28 d. Silymarin 100 mg/kg/day; p. o. was used as a standard drug. The whole study was divided into a prophylactic and curative study. In the prophylactic study, the Silymarin and QILE (test drug) 100, 200, and 400 mg/kg Body Weight(BW) given orally one hour before administration of 40% ethanol administration for 28 d. In the curative study, 7 d of treatment of Silymarin and QILE 200 and 400 mg/kg BW was given orally after 28 d of ethanol administration to different groups. Results: Hepatoprotectivity was confirmed by the highly significantly (p<0.001) restoration of elevated biochemical parameters like SGPT, SGOT, ALP, TB, and highly significantly (p<0.001) depleted Albumin and Total protein levels by 200 mg/kg BW QILE in comparison to the positive control group. QILE 200 mg/kg highly significantly (p<0.001) raised the antioxidants by draining the elevated oxidative stress markers in comparison of positive control group. At dose levels QILE 200 mg/kg, significant (p<0.05) protection from loss in body weight and in liver weight was found when the comparison was done with the positive control group. Histopathology revealed that QILE 200 mg/kg reduced the markers of cell necrosis. Conclusion: Present study revealed that Quercus ilex leaves have antioxidant and hepatoprotective activity due to its chemical constituents

Source of the Bursty Bulk Flow Diffuse Aurora: Electrostatic Cyclotron Harmonic and Whistler Waves in the Coupling of Bursty Bulk Flows to Auroral Precipitation

Electron cyclotron harmonic (ECH) and whistler chorus waves are recognized as the two mechanisms responsible for the resonant waveparticle interactions necessary to precipitate plasma sheet electrons into the ionosphere, producing the diffuse Aurora. Previous work has demonstrated ECH waves dominate electron scattering at L shells >8, while whistler chorus dominates scattering at L shells L 1, consistent with electron betatron acceleration. Here, however, we nd whistler chorus emissions throughout an interval of fast ows where Te,/Te,||< 1. Parallel electron beams account for the enhanced parallel electron temperature and serve as the instability mechanism for the whistler chorus. The parallel electron beams and associated cigarshaped distributions are consistent with Fermi acceleration at dipolarizations in fast ows. We demonstrate that the scattering efciency of the whistler chorus exceeds that of ECH waves, which THEMIS also detects during the fast ows. The obliquity of the whistler waves permits efcient scattering of lowerenergy electrons into the diffuse aurora. We conclude that Fermi acceleration of electrons provides one important freeenergy source for the waveparticle interactions responsible for coupling plasma sheet electrons into the diffuse aurora during substorm conditions

Estimation of Drag Coefficient from Radar-tracked Flight Data of a Cargo Shell

Two schemes to extract drag coefficient (C,) by processing the radar-tracked trajectories of artillery shell in motion, have been proposed. Flight trajectories of artillery shell are considered. The proposed schemes are applied on the radar-tracked trajectory data of artillery shell to estimate thc C,,. The C,, is strong function of Mach number. To capturc the functional rclationship between the C, and the Mach number, the C, of the ammunition was assumed to be a polynomial function of Mach number (separately for subsonic and supersonic). The coefficients of the assumed polynomial were estimated by minimising the error between measured and estimated trajectories. In the second scheme, whole trajectory was split into diffcrent sets containing 50 or 100 data points. Each data set was processed using the proposed schemes to estimate numerical values of C, corresponding to the average Mach number of the chosen data set. The estimated values of the C, (at different Mach numbers) have been presented along with its standard deviations. The difticulties encountered in processing the real trajectory data using the proposed schemes are also highlighted. It is observed that thc proposed schclnes could advantageously be applied to quickly estimate the numerical values of the C, at corresponding Mach numbers, by processing thc trajectory data of an artillcry shell in motion

A new data analysis framework for the search of continuous gravitational wave signals

Continuous gravitational wave signals, like those expected by asymmetric spinning neutron stars, are among the most promising targets for LIGO and Virgo detectors. The development of fast and robust data analysis methods is crucial to increase the chances of a detection. We have developed a new and flexible general data analysis framework for the search of this kind of signals, which allows to reduce the computational cost of the analysis by about two orders of magnitude with respect to current procedures. This can correspond, at fixed computing cost, to a sensitivity gain of up to 10%-20%, depending on the search parameter space. Some possible applications are discussed, with a particular focus on a directed search for sources in the Galactic center. Validation through the injection of artificial signals in the data of Advanced LIGO first observational science run is also shown.Comment: 21 pages, 8 figure

Studies on the Thermodynamics of Exchange in Clays: Part II - Zinc Exchange on Na- & Ca-Illites

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An improved algorithm for narrow-band searches of continuous gravitational waves

Continuous gravitational waves signals, emitted by asymmetric spinning neutron stars, are among the main targets of current detectors like Advanced LIGO and Virgo. In the case of sources, like pulsars, which rotational parameters are measured through electromagnetic observations, typical searches assume that the gravitational wave frequency is at a given known fixed ratio with respect to the star rotational frequency. For instance, for a neutron star rotating around one of its principal axis of inertia the gravitational signal frequency would be exactly two times the rotational frequency of the star. It is possible, however, that this assumption is wrong. This is why search algorithms able to take into account a possible small mismatch between the gravitational waves frequency and the frequency inferred from electromagnetic observations have been developed. In this paper we present an improved pipeline to perform such narrow-band searches for continuous gravitational waves from neutron stars, about three orders of magnitude faster than previous implementations. The algorithm that we have developed is based on the {\it 5-vectors} framework and is able to perform a fully coherent search over a frequency band of width $\mathcal{O}$(Hertz) and for hundreds of spin-down values running a few hours on a standard workstation. This new algorithm opens the possibility of long coherence time searches for objects which rotational parameters are highly uncertain.Comment: 19 pages, 8 figures, 6 tables, submitted to CQ

Cognitive debiasing 2: Impediments to and strategies for change

In a companion paper, we proposed that cognitive debiasing is a skill essential in developing sound clinical reasoning to mitigate the incidence of diagnostic failure. We reviewed the origins of cognitive biases and some proposed mechanisms for how debiasing processes might work. In this paper, we first outline a general schema of how cognitive change occurs and the constraints that may apply. We review a variety of individual factors, many of them biases themselves, which may be impediments to change. We then examine the major strategies that have been developed in the social sciences and in medicine to achieve cognitive and affective debiasing, including the important concept of forcing functions. The abundance and rich variety of approaches that exist in the literature and in individual clinical domains illustrate the difficulties inherent in achieving cognitive change, and also the need for such interventions. Ongoing cognitive debiasing is arguably the most important feature of the critical thinker and the well-calibrated mind. We outline three groups of suggested interventions going forward: educational strategies, workplace strategies and forcing functions. We stress the importance of ambient and contextual influences on the quality of individual decision making and the need to address factors known to impair calibration of the decision maker. We also emphasise the importance of introducing these concepts and corollary development of training in critical thinking in the undergraduate level in medical education