Length-weight relationship and relative condition factor of the Stone Scorpionfish Scorpaena mystes in the central area of the Gulf of California, Mexico

Background. In recent years (since 2012) there has been an increase in the commercial exploitation of Scorpaena mystes Jordan & Starks, 1985 in the central area of the Gulf of California and there is no information on the basic biology of this species that serve as a basis to determine the current population status and, in the future, assess any changes associated with exploitation and environmental factors. Goals. Determine the length-weight (LWR) and length-length (LLR) relationships, and the relative condition factor of S. mystes. Methods. Fish specimens (n = 258) were collected monthly from May 2015 through April 2016 in waters off Santa Rosalía, Baja California Sur. Each fish was measured for standard length (SL) and total length (TL), and weighed (W). Results. LWR and LLR were highly significant (p <0.05) with a determination coefficient higher than 0.9. The b-value (b = 3.06) of LWR was not significantly-different from 3. Monthly variation in the relative condition factor was also significant (p <0.05) with the highest value in August (1.34). Conclusions. The growth of S. mystes is isometric. The monthly variation in the condition factor may be associated with maturation of the gonads of the species.Background. In recent years (since 2012) there has been an increase in the commercial exploitation of Scorpaena mystes Jordan & Starks, 1985 in the central area of the Gulf of California and there is no information on the basic biology of this species that serve as a basis to determine the current population status and, in the future, assess any changes associated with exploitation and environmental factors. Goals. Determine the length-weight (LWR) and length-length (LLR) relationships, and the relative condition factor of S. mystes. Methods. Fish specimens (n = 258) were collected monthly from May 2015 through April 2016 in waters off Santa Rosalía, Baja California Sur. Each fish was measured for standard length (SL) and total length (TL), and weighed (W). Results. LWR and LLR were highly significant (p <0.05) with a determination coefficient higher than 0.9. The b-value (b = 3.06) of LWR was not significantly-different from 3. Monthly variation in the relative condition factor was also significant (p <0.05) with the highest value in August (1.34). Conclusions. The growth of S. mystes is isometric. The monthly variation in the condition factor may be associated with maturation of the gonads of the species

The Santa Fe Light Cone Simulation Project: II. The Prospects for Direct Detection of the WHIM with SZE Surveys

Detection of the Warm-Hot Intergalactic Medium (WHIM) using Sunyaev-Zeldovich effect (SZE) surveys is an intriguing possibility, and one that may allow observers to quantify the amount of "missing baryons" in the WHIM phase. We estimate the necessary sensitivity for detecting low density WHIM gas with the South Pole Telescope (SPT) and Planck Surveyor for a synthetic 100 square degree sky survey. This survey is generated from a very large, high dynamic range adaptive mesh refinement cosmological simulation performed with the Enzo code. We find that for a modest increase in the SPT survey sensitivity (a factor of 2-4), the WHIM gas makes a detectable contribution to the integrated sky signal. For a Planck-like satellite, similar detections are possible with a more significant increase in sensitivity (a factor of 8-10). We point out that for the WHIM gas, the kinematic SZE signal can sometimes dominate the thermal SZE where the thermal SZE decrement is maximal (150 GHz), and that using the combination of the two increases the chance of WHIM detection using SZE surveys. However, we find no evidence of unique features in the thermal SZE angular power spectrum that may aid in its detection. Interestingly, there are differences in the power spectrum of the kinematic SZE, which may not allow us to detect the WHIM directly, but could be an important contaminant in cosmological analyses of the kSZE-derived velocity field. Corrections derived from numerical simulations may be necessary to account for this contamination.Comment: 9 pages, submitted to Astrophysical Journa

Experimental modulation of capsule size in Cryptococcus neoformans

Experimental modulation of capsule size is an important technique for the study of the virulence of the encapsulated pathogen Cryptococcus neoformans. In this paper, we summarize the techniques available for experimental modulation of capsule size in this yeast and describe improved methods to induce capsule size changes. The response of the yeast to the various stimuli is highly dependent on the cryptococcal strain. A high CO(2) atmosphere and a low iron concentration have been used classically to increase capsule size. Unfortunately, these stimuli are not reliable for inducing capsular enlargement in all strains. Recently we have identified new and simpler conditions for inducing capsule enlargement that consistently elicited this effect. Specifically, we noted that mammalian serum or diluted Sabouraud broth in MOPS buffer pH 7.3 efficiently induced capsule growth. Media that slowed the growth rate of the yeast correlated with an increase in capsule size. Finally, we summarize the most commonly used media that induce capsule growth in C. neoformans

Three-Dimensional Reconstructions of Tadpole Chondrocrania from Histological Sections

Reconstructing three dimensional structures (3DR) from histological sections has always been difficult but is becoming more accessible with the assistance of digital imaging. We sought to assemble a low cost system using readily available hardware and software to generate 3DR for a study of tadpole chondrocrania. We found that a combination of RGB camera, stereomicroscope, and Apple Macintosh PowerPC computers running NIH Image, Object Image, Rotater. and SURFdriver software provided acceptable reconstructions. These are limited in quality primarily by the distortions arising from histological protocols rather than hardware or software

Hubble Space Telescope studies of low-redshift Type Ia supernovae: Evolution with redshift and ultraviolet spectral trends

We present an analysis of the maximum light, near ultraviolet (NUV; 2900-5500 A) spectra of 32 low redshift (0.001<z<0.08) Type Ia supernovae (SNe Ia), obtained with the Hubble Space Telescope (HST). We combine this spectroscopic sample with high-quality gri light curves obtained with robotic telescopes to measure photometric parameters, such as stretch, optical colour, and brightness. By comparing our data to a comparable sample of SNe Ia at intermediate-z (0.4<z<0.9), we detect modest spectral evolution (3-sigma), in the sense that our mean low-z NUV spectrum has a depressed flux compared to its intermediate-z counterpart. We also see a strongly increased dispersion about the mean with decreasing wavelength, confirming the results of earlier surveys. These trends are consistent with changes in metallicity as predicted by contemporary SN Ia spectral models. We also examine the properties of various NUV spectral diagnostics in the individual spectra. We find a general correlation between stretch and the velocity (or position) of many NUV spectral features. In particular, we observe that higher stretch SNe have larger Ca II H&K velocities, that also correlate with host galaxy stellar mass. This latter trend is probably driven by the well-established correlation between stretch and stellar mass. We find no trends between UV spectral features and optical colour. Mean spectra constructed according to whether the SN has a positive or negative Hubble residual show very little difference at NUV wavelengths, indicating that the NUV evolution and variation we identify do not directly correlate with Hubble residuals. Our work confirms and strengthens earlier conclusions regarding the complex behaviour of SNe Ia in the NUV spectral region, but suggests the correlations we find are more useful in constraining progenitor models than improving the use of SNe Ia as cosmological probes.Comment: 22 pages, 14 figures, accepted in MNRAS with minor changes - Spectra are available on WISeREP, http://www.weizmann.ac.il/astrophysics/wiserep

Five Dimensional Cosmological Models in General Relativity

A Five dimensional Kaluza-Klein space-time is considered in the presence of a perfect fluid source with variable G and $\Lambda$. An expanding universe is found by using a relation between the metric potential and an equation of state. The gravitational constant is found to decrease with time as $G \sim t^{-(1-\omega)}$ whereas the variation for the cosmological constant follows as $\Lambda \sim t^{-2}$, $\Lambda \sim (\dot R/R)^2$ and $\Lambda \sim \ddot R/R$ where $\omega$ is the equation of state parameter and $R$ is the scale factor.Comment: 13 pages, 4 figures, accepted in Int. J. Theor. Phy

Editorial: African women's struggles in a gender perspective

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