Implications of uniformly distributed, empirically informed priors for phylogeographical model selection: A reply to Hickerson et al

Establishing that a set of population-splitting events occurred at the same time can be a potentially persuasive argument that a common process affected the populations. Oaks et al. (2013) assessed the ability of an approximate-Bayesian method (msBayes) to estimate such a pattern of simultaneous divergence across taxa, to which Hickerson et al. (2014) responded. Both papers agree the method is sensitive to prior assumptions and often erroneously supports shared divergences; the papers differ about the explanation and solution. Oaks et al. (2013) suggested the method's behavior is caused by the strong weight of uniform priors on divergence times leading to smaller marginal likelihoods of models with more divergence-time parameters (Hypothesis 1); they proposed alternative priors to avoid strongly weighted posteriors. Hickerson et al. (2014) suggested numerical approximation error causes msBayes analyses to be biased toward models of clustered divergences (Hypothesis 2); they proposed using narrow, empirical uniform priors. Here, we demonstrate that the approach of Hickerson et al. (2014) does not mitigate the method's tendency to erroneously support models of clustered divergences, and often excludes the true parameter values. Our results also show that the tendency of msBayes analyses to support models of shared divergences is primarily due to Hypothesis 1. This series of papers demonstrate that if our prior assumptions place too much weight in unlikely regions of parameter space such that the exact posterior supports the wrong model of evolutionary history, no amount of computation can rescue our inference. Fortunately, more flexible distributions that accommodate prior uncertainty about parameters without placing excessive weight in vast regions of parameter space with low likelihood increase the method's robustness and power to detect temporal variation in divergences.Comment: 24 pages, 4 figures, 1 table, 14 pages of supporting information with 10 supporting figure

Optimum Linkage for Biped Mechanism

AbstractLocomotion of a robot has been achieved with many possible solutions like legged or wheeled type. But the optimum linkage mechanism for a biped robot is yet to be specified for the purpose of walking. In this paper, different types of linkages depending upon their degree of freedom (DOF) have been compared and the best of them have been selected with help of ADMAS software. The biped mechanism consists of only two legs that are connected at the hip joint and are used for the locomotion of the robot/humanoid. This mechanism is selected based on parameters which are force developed in joints, trajectory of centre of mass (COM) of links and kinetic energy attained by all the links

Toxic effect of copper sulphate on protein alterations in esturine fish, Mugil cephalus

Heavy metals are common pollutants of estuarine ecosystems where they induce adverse effects on the aquatic biota. Copper is one of the most toxic heavy metal to fish and consumption of fish after copper treatment in water may pose a serious risk to human health. Fishes are generally used as pollution indicators in water quality management. Chronic effects include reduced growth, shorter lifespan, reproductive problems, reduced fertility and behavioral changes. Esturine fish, Mugil cephalus is an important fin fish species of Uppanar estury in Cuddalore region having good nutritional values. Fishes living in close association with the sediment may accumulate copper sulphate. In the present observation, the toxic effects of the copper sulphate LC50 35 μg/L (CuSO4) on (10% and 30%) two sublethal concentrations of total protein in gill, liver and muscles tissues of the esturine fish, Mugil cephalus were estimated during the periods of 5, 10 and 15 days exposure. There is decreased in all tissues on comparison with control. The results indicated the toxic nature of the heavy metal copper sulphate

NSAIDs for analgesia in the era of COVID-19

Globally, non-steroidal anti-inflammatory drugs (NSAIDs) are highly used to treat pain. With the rise of the COVID-19 pandemic, the safety of NSAIDs use has been called into question. These concerns are worthy of review. At present, there is no compelling data showing that NSAIDs worsen the severity of COVID-19 symptoms or increase one\u27s likelihood of contracting the illness. For patients in pain and without symptoms that could potentially be attributed to COVID-19 (cough, fevers/chills, lethargy, myalgias, anosmia and so on), NSAIDs should continue to remain a viable option to provide analgesia to patients in need

On the influence of spatial heterogeneity on an internal boundary layer at a short fetch

Surface layer meteorological data collected at a coastal site, at Vasco-Da-Gama (15°21′N, 73°51′E, 58.5m MSL) (13–18 July, 2002) with prevailing southwesterly surface winds are analyzed to study the characteristics of internal boundary layer at a short fetch using an instrumented tower (9 m). The spectral and turbulence characteristics of wind are compared with earlier measurements made at a comparatively homogeneous terrain and the standards available in literature. The study show the smaller eddies in the vertical velocity spectrum attains equilibrium with the underlying surface at a short fetch itself and follows spectral similarity. However, this is not followed by longitudinal and transverse velocity spectra under unstable as well as stable condition

Swinging and tumbling of elastic capsules in shear flow

The deformation of an elastic micro-capsule in an infinite shear flow is studied numerically using a spectral method. The shape of the capsule and the hydrodynamic flow field are expanded into smooth basis functions. Analytic expressions for the derivative of the basis functions permit the evaluation of elastic and hydrodynamic stresses and bending forces at specified grid points in the membrane. Compared to methods employing a triangulation scheme, this method has the advantage that the resulting capsule shapes are automatically smooth, and few modes are needed to describe the deformation accurately. Computations are performed for capsules both with spherical and ellipsoidal unstressed reference shape. Results for small deformations of initially spherical capsules coincide with analytic predictions. For initially ellipsoidal capsules, recent approximative theories predict stable oscillations of the tank-treading inclination angle, and a transition to tumbling at low shear rate. Both phenomena have also been observed experimentally. Using our numerical approach we could reproduce both the oscillations and the transition to tumbling. The full phase diagram for varying shear rate and viscosity ratio is explored. While the numerically obtained phase diagram qualitatively agrees with the theory, intermittent behaviour could not be observed within our simulation time. Our results suggest that initial tumbling motion is only transient in this region of the phase diagram.Comment: 20 pages, 7 figure

Effects and consequences of small-scale cage culture technology adoption in Kerala

Small-scale fish farming is critical in ensuring food security and employment in many developing countries. Small-scale cage culture for Etroplus suratensis was introduced in the state by the Department of Fisheries, Government of Kerala with the same objectives. The demand for the species has shown considerable increase in the recent years and f m gate prices are as high as Rs 450kg in the peak season. Elevation to the status of State Fish has also helped the culture of the species in attracting the attention of policy makers leading to promotion of its culture. Cage culture in brackishwater bodies, a relatively new technology to the State, was popularized among the tsunami affected fishermen along with extension and technical support. The implementation of cage culture was promoted through the Brackishwater Fish Farmers' Development Agency (BFFDAs) and Agency for Development ofAquaculture Kerala (ADAK), two subsidiaries of the Department of Fisheries, Government of Kerala. The present study probes the effects and consequences of cage culture technology adoption among farmers based on primary data collected from sample respondents during the initial year of culture

Stabilization of Black Cotton Soil using Lime, Coir Fiber & Rice Husk

Because of their low bearing capacity, the expansive black cotton soils' high swelling and shrinking characteristics have posed numerous challenges to construction projects. When subjected to varying levels of moisture, black cotton soil expands and contracts rapidly. As a result, stabilising the soil is necessary to address these issues. Rice Husk Ash (RHA), Cori Fiber, and Lime are being tested in this study to see if they can act as a stabilising material in the expansive black cotton soil. The impact of RHA, CF, and LIME on the expansive soil's index and engineering properties was studied in the lab. Coir fibre concentration is 1.5 percent, lime is 5 percent by weight of dry soil, and RHA is mixed in at a ratio of 20 percent. The virgin soil sample is first tested for specific gravity and grain size distribution. With and without these admixtures soil's index properties like its plastic limit, liquid limit and shrinkage limit and its strength properties like its California Bearing Ratio, Unconfined Compressive Strength tests are discovered. According to the test results, a combination of 5 percent lime and 1.5 percent coir fibre yielded the strongest soil and best index properties

Some observations on the chemistry of glycerides-Part I

A critical analysis of the trisaturated glyceride content of fats shows that the natural fats are characterised by definite numerical relationships between the proportions of GS3 experimentally determined and those possible according to chance distribution and that the ratio between these is a specific characteristic of the source