Cell Rearrangement and Directional Migration in Pronephric Duct Development

The morphology of the directed migration of the pronephric duct rudiment of three vertebrates, the salamander, chick and sturgeon, has been examined by scanning electron microscopy. Of particular interest in this paper are the morphology of the duct tip, the role of cell rearrangement, and the relation of duct extension to somite segmentation. The duct rudiments of all three species have motile cell processes (lamellipodia and filopodia) largely confined to their posterior tips. The salamander and sturgeon embryos extend their duct rudiments by extensive cell rearrangements. A short, wide rudiment is elongated to form a long, thin one. The chick duct rudiment stays about the same width and apparently gains volume by cell proliferation. The salamander duct rudiment\u27s posterior tip is always two somites behind the last formed somite. Both the sturgeon and chick embryo\u27s duct rudiments lie well posterior of the last segmented somite adjacent to segmental plate mesoderm. There is still a close coupling, however, between the posterior progression of the duct rudiments and the advancing wave of somite segmentation

Developmental Angiogenesis: Quail Embryonic Vasculature

We have examined the segregation and early morphogenesis of the embryonic vasculature by using a monoclonal antibody for immunofluorescence and by scanning electron microscopy. This antibody labels the presumptive endothelial eel ls (PECs) as they segregate from mesoderm. Similar embryos prepared for SEM revealed finer details of how these segregated cells interact to form the rudiments of the major blood vessels. Here we concentrate on the development of the dorsal aortae and the posterior cardinal veins. The dorsal aortae form from single PECs which segregate from the lateral mesoderm and aggregate into a loose cord ventral to the somites. These cells become more closely associated and a lumen forms. The posterior cardinal veins form from a loose plexus of cells segregated from the lateral mesoderm on its dorsal surface. These cells become intimately associated with the Wolffian ducts

Dark Energy Survey year 1 results: Galaxy clustering for combined probes

We measure the clustering of DES year 1 galaxies that are intended to be combined with weak lensing samples in order to produce precise cosmological constraints from the joint analysis of large-scale structure and lensing correlations. Two-point correlation functions are measured for a sample of 6.6×10^5 luminous red galaxies selected using the REDMAGIC algorithm over an area of 1321 square degrees, in the redshift range 0.15 0.5, b(σ_8/0.81)|_(z = 0.68) = 1.93±0.04 for L/L∗ > 1 and b(σ_8/0.81)|_(z = 0.83) = 1.98±0.07 for L/L∗ > 1.5, broadly consistent with expectations for the redshift and luminosity dependence of the bias of red galaxies. We show these measurements to be consistent with the linear bias obtained from tangential shear measurements

Magnetic susceptibility of ultra-small superconductor grains

For assemblies of superconductor nanograins, the magnetic response is analyzed as a function of both temperature and magnetic field. In order to describe the interaction energy of electron pairs for a huge number of many-particle states, involved in calculations, we develop a simple approximation, based on the Richardson solution for the reduced BCS Hamiltonian and applicable over a wide range of the grain sizes and interaction strengths at arbitrary distributions of single-electron energy levels in a grain. Our study is focused upon ultra-small grains, where both the mean value of the nearest-neighbor spacing of single-electron energy levels in a grain and variations of this spacing from grain to grain significantly exceed the superconducting gap in bulk samples of the same material. For these ultra-small superconductor grains, the overall profiles of the magnetic susceptibility as a function of magnetic field and temperature are demonstrated to be qualitatively different from those for normal grains. We show that the analyzed signatures of pairing correlations are sufficiently stable with respect to variations of the average value of the grain size and its dispersion over an assembly of nanograins. The presence of these signatures does not depend on a particular choice of statistics, obeyed by single-electron energy levels in grains.Comment: 40 pages, 12 figures, submitted to Phys. Rev. B, E-mail addresses: [email protected], [email protected], [email protected]

Extraction of Visual Information to Predict Crowdfunding Success

Researchers have increasingly turned to crowdfunding platforms to gain insights into entrepreneurial activity and dynamics. While previous studies have explored various factors influencing crowdfunding success, such as technology, communication, and marketing strategies, the role of visual elements that can be automatically extracted from images has received less attention. This is surprising, considering that crowdfunding platforms emphasize the importance of attention-grabbing and high-resolution images, and previous research has shown that image characteristics can significantly impact product evaluations. Indeed, a comprehensive review of empirical articles (n = 202) that utilized Kickstarter data, focusing on the incorporation of visual information in their analyses. Our findings reveal that only 29.70% controlled for the number of images, and less than 12% considered any image details. In this manuscript, we review the literature on image processing and its relevance to the business domain, highlighting two types of visual variables: visual counts (number of pictures and number of videos) and image details. Building upon previous work that discussed the role of color, composition and figure-ground relationships, we introduce visual scene elements that have not yet been explored in crowdfunding, including the number of faces, the number of concepts depicted, and the ease of identifying those concepts. To demonstrate the predictive value of visual counts and image details, we analyze Kickstarter data. Our results highlight that visual count features are two of the top three predictors of success. Our results also show that simple image detail features such as color matter a lot, and our proposed measures of visual scene elements can also be useful. We supplement our article with R and Python codes that help authors extract image details (https://osf.io/ujnzp/).Comment: 32 pages, 5 figure

Greater V˙O2peak is correlated with greater skeletal muscle deoxygenation amplitude and hemoglobin concentration within individual muscles during ramp-incremental cycle exercise.

It is axiomatic that greater aerobic fitness (V˙O2peak) derives from enhanced perfusive and diffusive O2 conductances across active muscles. However, it remains unknown how these conductances might be reflected by regional differences in fractional O2 extraction (i.e., deoxy [Hb+Mb] and tissue O2 saturation [StO2]) and diffusive O2 potential (i.e., total[Hb+Mb]) among muscles spatially heterogeneous in blood flow, fiber type, and recruitment (vastus lateralis, VL; rectus femoris, RF). Using quantitative time-resolved near-infrared spectroscopy during ramp cycling in 24 young participants (V˙O2peak range: ~37.4-66.4 mL kg-1 min-1), we tested the hypotheses that (1) deoxy[Hb+Mb] and total[Hb+Mb] at V˙O2peak would be positively correlated with V˙O2peak in both VL and RF muscles; (2) the pattern of deoxygenation (the deoxy[Hb+Mb] slopes) during submaximal exercise would not differ among subjects differing in V˙O2peak Peak deoxy [Hb+Mb] and StO2 correlated with V˙O2peak for both VL (r = 0.44 and -0.51) and RF (r = 0.49 and -0.49), whereas for total[Hb+Mb] this was true only for RF (r = 0.45). Baseline deoxy[Hb+Mb] and StO2 correlated with V˙O2peak only for RF (r = -0.50 and 0.54). In addition, the deoxy[Hb+Mb] slopes were not affected by aerobic fitness. In conclusion, while the pattern of deoxygenation (the deoxy[Hb+Mb] slopes) did not differ between fitness groups the capacity to deoxygenate [Hb+Mb] (index of maximal fractional O2 extraction) correlated significantly with V˙O2peak in both RF and VL muscles. However, only in the RF did total[Hb+Mb] (index of diffusive O2 potential) relate to fitness

Nucleosynthetic and Mass-Dependent Molybdenum Isotope Anomalies in Iron Meteorites:Constraints on Solar Nebula Heterogeneities and Parent Body Processes

While iron meteorite parent bodies exhibit variable deficits in s-process Mo isotopes, they feature essentially identical stable Mo isotope compositions

A-Z of postural care: how to have a good posture when sitting, standing, exercising and relaxing, a guide for teachers and parents and everyone

An A to Z of Postural Care was designed to help those who work with children with postural care needs. It has been written jointly by specialist teachers, therapists and parents of children with physical impairments. The information provided is informed by research that explored the views of teachers and teaching assistants about their experiences of looking after children with physical impairments in mainstream primary schools in Kent. This A to Z booklet aims to give basic information and may act as a starting point for discussions with the therapy team, the child’s family and others in the school. It should link to more general awareness raising within a school of the importance of good posture for learning. The A-Z can be used together with other POSTED training materials to provide the basis for a training programme for parents and teachers. When using/referring to this booklet please acknowledge authorship as appropriate. Details of the other POSTED training resources and publications can be found at CREATE http://create.canterbury.ac.uk/ Hutton, E. and Coxon, K. (2011) Posture for learning: meeting the postural care needs of children with physical disabilities in mainstream primary schools in England - a research into practice exploratory study. Disability and Rehabilitation. 33 (19–20), pp.1012–1924

Microstructure of nanocrystalline diamond powders studied by powder diffractometry

High resolution x-ray diffraction peaks of diamond nanosize powders of nominal sizes ranging from 5 to 250 nm were analyzed and provided information on grain structure, average size of crystallites, and concentration of dislocations. Selected samples were heat treated at 1670 K at pressures 2.0 and 5.5 GPa or had surface modified by outgassing, heat treatment at vacuum conditions, and by controlled adsorption of gases. The apparent lattice parameter method was applied to characterize the structure of a shell-core model of nanosize particles. The multiple whole profile fitting provided information on crystallite sizes and density of dislocations. Population of dislocations increased with applied pressure, while strain and interplanar distances in the surface layers decreased. Adsorption of foreign gases on the grain surface modified the structure of the surface layers but did not affect dislocations near the center of the grains