Embryonic development of endoderm in chicken (Gallus gallus domesticus)

The poultry industry is a sector of agribusiness which represents an important role in the country's agricultural exports. Therefore, the study about embryogenesis of the domestic chicken (Gallus gallus domesticus) has a great economic importance. The aim of this study was to evaluate embryonic development of the endoderm in chicken (Gallus gallus domesticus). Forty fertilized eggs of domestic chickens, starting from the 1st day of gestation and so on until the 19 days of the incubation were collected from the Granja São José (Amparo, SP, Brazil). Embryos and fetus were fixed in 10% formaldehyde solution, identified, weighed, measured, and subjected to light and scanning electron microscopy. The endoderm originates the internal lining epithelium of the digestive, immune, respiratory systems, and the organs can be visualized from the second day (48 h) when the liver is formed. The formation of the digestive system was complete in the 12th day. Respiratory system organs begin at the fourth day as a disorganized tissue and undifferentiated. Their complete differentiation was observed at the 10 days of incubation, however, until the 19 days the syrinx was not observed. The formation of immune system at 10th day was observed with observation of the spleen, thymus, and cloacal bursa. The study of the organogenesis of the chicken based on germ layers is very complex and underexplored, and the study of chicken embryology is very important due the economic importance and growth of the use of this animal model studies such as genetic studies. Microsc. Res. Tech. 76:803–810, 2013. © 2013 Wiley Periodicals, Inc.     

Posttraumatic stress disorder and the genetic structure of comorbidity.

This study used structural equation modeling to examine the genetic and environmental architecture of latent dimensions of internalizing and externalizing psychiatric comorbidity and explored structural associations between posttraumatic stress disorder (PTSD) and these dimensions. Data were drawn from the Vietnam Era Twin Registry and included lifetime diagnoses for PTSD and a range of other psychiatric disorders for 3,372 male–male twin pairs. Examination of the phenotypic structure of these disorders revealed that PTSD cross-loaded on both Internalizing and Externalizing common factors. Biometric analyses suggested largely distinct genetic risk factors for the latent internalizing and externalizing comorbidity dimensions, with the total heritability of the Externalizing factor (69%) estimated to be significantly stronger than that for Internalizing (41%). Nonshared environment explained the majority of the remaining variance in the Internalizing (58%) and Externalizing (20%) factors. Shared genetic variance across the 2 dimensions explained 67% of their phenotypic correlation (r = .52). These findings have implications for conceptualizations of the etiology of PTSD and its location in an empirically based nosology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dynamics of water in agar gels studied using low and high resolution 1H NMR spectroscopy

The aim of this work was to determine whether the decreased motion of water in agar gels (2.5–12.5% agar) resulted not only from the chemical interaction of the water molecules with the agar macromolecules but also from obstruction by the gel networks. Relaxation experiments were conducted using a 500‐MHz nuclear magnetic resonance (NMR) spectrometer. Diffusion experiments were conducted using a 23‐MHz NMR spectrometer with diffusion times ranging between 15 and 200 ms and a 500‐MHz NMR spectrometer with a fixed diffusion time of 10 ms. This study shows that the interaction of water with hydroxyl groups of agar macromolecules resulted in faster relaxation and slower self‐diffusion of water. The time‐dependent self‐diffusion coefficient of water provides clear evidence of the obstructive effects of the agar gel network on diffusion. This work is the first report on restricted diffusion of water in agar gel systems.     

Modification of cellulose‐based packaging materials for enzyme immobilization

Active cellulose‐based packaging materials were prepared by binding lysozyme to paper modified with anionic polyelectrolytes. Polyelectrolytes improve the paper binding capacity towards the positively charged lysozyme and play a protective role towards lysozyme activity during the paper‐making process. The charge density of paper was increased by incorporating carboxymethylcellulose (CMC) or polygalacturonic acid (PGA). The presence of either CMC or PGA greatly increased the amount of bound lysozyme, and the stability of its binding towards buffers or towards non‐ionic chaotropes which disrupt the three dimensional structure in macromolecules (urea, 8 M). Binding of lysozyme to modified papers was sensitive to anionic detergents (sodium dodecyl sulphate, 1%) and to non‐chaotrope salts (NaCl, 0.5M). These data provide information about the nature of the interactions between the protein and the various types of paper, and provide insights on how to preserve the activity of lysozyme‐loaded paper. The polymers used for lysozyme immobilization were found to affect only marginally the structural and functional properties of the antimicrobial protein, and to facilitate the recovery of structural features of the protein after heat treatment. Presence of a negative polyelectrolyte (and of CMC in particular) improves the thermal stability of the protein, making it resistant to thermal inactivation, even under the conditions used for drying processes without compromising the paper's mechanical properties. The activity measurements showed that paper‐bound lysozyme retains its lytic (and therefore, antimicrobial) activity against the cell walls of Micrococcus lysodeikticus, the target microrganism used as standard for lysozyme bioassays. Copyright © 2009 John Wiley & Sons, Ltd.     

A recent review of non‐biological remediation of aflatoxin‐contaminated crops

Aflatoxins are highly toxic, mutagenic, teratogenic and carcinogenic compounds produced predominantly as secondary metabolites by certain species of fungi belonging to the Aspergillus genus. Owing to the significant health risks and economic impacts associated with the presence of aflatoxins in agricultural commodities, a considerable amount of research has been directed at finding methods to prevent toxicity. This review compiles the recent literature of methods for the detoxification and management of aflatoxin in post‐harvest agricultural crops using non‐biological remediation. © 2013 Society of Chemical Industry     

Meta-insight: Do people really know how others see them?

Although people can accurately guess how others see them, many studies have suggested that this may only be because people generally assume that others see them as they see themselves. These findings raise the question: In their everyday lives, do people understand the distinction between how they see their own personality and how others see their personality? We examined whether people make this distinction, or whether people possess what we call meta-insight. In 3 studies, we assessed meta-insight for a broad range of traits (e.g., Big Five, intelligent, funny) across several naturalistic social contexts (e.g., first impression, friends). Our findings suggest that people can make valid distinctions between how they see themselves and how others see them. Thus, people seem to have some genuine insight into their reputation and do not achieve meta-accuracy only by capitalizing on the fact that others see them similarly to how they see themselves. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Thomas Glaister and early Australian photography

Abstract

In common with research into the early photographic history of most colonial societies, attempts to learn more about the photographers who worked in nineteenth-century Australia can be an exasperating exercise. Many of these early practitioners arrived in Australia as immigrants from Europe or America, often intent on concealing their origins, or, more optimistically, simply wanting to establish a new life in a new country without the encumbrances of their own pasts. Despite the technical skill and the cumbersome equipment required to produce early photographic images, many new arrivals in the colony took up photography principally as a means of making money, either as itinerant country photographers (Jack Cato called Australian photography in the 1840s a ‘vagrant process’¹) or, later in the cities, through studio portraiture and views of colonial streets and buildings. Aesthetic considerations were often secondary to the desire for a ‘good likeness’ produced in the shortest amount of time.     

Removal of alkylphenols by the combined use of tyrosinase immobilized on ion‐exchange resins and chitosan beads

Mushroom tyrosinase was covalently immobilized on a poly(acrylic acid)‐type, weakly acidic cation‐exchange resin (Daiaion WK10, Mitsubishi Chemical Corp., Tokyo, Japan) with 1‐ethyl‐3‐(3‐dimethylaminopropyl)carbodiimide hydrochloride salt as a water‐soluble carbodiimide. Ion‐exchange resins immobilized with tyrosinase were packed in one column, and crosslinked chitosan beads prepared with epichlorohydrin were packed in another column. The enzymatic activity was modified by covalent immobilization, and the immobilized tyrosinase had a high activity in the temperature range of 30–45°C and in the pH range of 7–10. When solutions of various alkylphenols were circulated through the two columns packed with tyrosinase‐immobilized ion‐exchange resins and crosslinked chitosan beads at 45°C and pH 7 (the optimum conditions determined for p‐cresol), alkylphenols were effectively removed through quinone oxidation with immobilized tyrosinase and subsequent quinone adsorption on chitosan beads. The use of chemically crosslinked chitosan beads in place of commercially available chitosan beads was effective in removing alkylphenols from aqueous solutions in shorter treatment times. The removal efficiency increased with an increase in the amount of crosslinked chitosan beads packed in the column because the rate of quinone adsorption became higher than the rate of enzymatic quinone generation. The activity of tyrosinase was iteratively used by covalent immobilization on ion‐exchange resins. One of the most important findings obtained in this study is the fact that linear and branched alkylphenols suspected of weak endocrine‐disrupting effects were effectively removed from aqueous solutions. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Corrosion protection with zinc-rich epoxy paint coatings embedded with various amounts of highly dispersed polypyrrole-deposited alumina monohydrate particles

Active anodic zinc content below 90 wt.% does not support sufficient electrical contacts but higher contents cause high porosity of traditional liquid zinc-rich paints (ZRPs). To resolve this problem, our proposal is the application of highly dispersed polypyrrole (PPy) coated alumina inhibitor particles (PCAIPs) in zinc-rich paint compositions. Using these nano-size inhibitor particles at concentrations from 4.55 to 0.85 wt.%, hybrid paints were formulated with zinc contents ranging from 60 to 85 wt.% at the same time. Submicron morphology and nano-scale structure, spectroscopy characteristics and electrochemical properties of the PCAIPs were studied by transmission electron microscopy (TEM) and rheology, Fourier-transform infrared spectroscopy (FT-IR) and cyclic voltammetry (CV) in first part of the work. In the second part, electrolytic corrosion resistivity of two sets of paint coatings were salt-spray chamber and immersion tested with 5 wt.% aqueous solution of sodium chloride. Active corrosion prevention ability of the salt-spray tested coatings was evaluated in compliance with ISO recommendations. Dielectric properties of the coatings during the immersion tests were monitored by electrochemical impedance spectroscopy (EIS). Corrosion tested area of the coatings was investigated by glow-discharge optical emission spectroscopy (GD-OES) to disclose infiltration of corrosive analytes and oxygen enrichment in the cross-section of the primers in comparison with their pristine states. Morphology of the zinc pigments was examined by scanning electron microscopy (SEM), and quality of steel specimens and the interfacial binder residues by X-ray photoelectron spectroscopy (XPS) as well as FT-Raman and Mössbauer spectroscopy. The results of both types of corrosion tests evidenced efficient utilisation of sacrificial anodic current for galvanic protection and improved barrier profile of the hybrid coatings, along with the PCAIP inhibited moderate self-corrosion of zinc. As a result of well balanced active/passive function, the hybrid coating containing zinc at 80 wt.% and PCAIPs at 1.75 wt.% embedding PPy at 0.056 wt.% indicated the most advanced corrosion prevention. Galvanic function of the hybrid paints is interpreted on the basis of size-range effect and spatial distribution of the alumina supported PPy inhibitor particles and basic electrical percolation model considerations.