Immigrants' adaptation in Canada: Assimilation, acculturation, and orthogonal cultural identification.

Reviews the predominant models developed by researchers to assess the psychological adaptation of immigrants in the host society. The use of the terms assimilation and acculturation to reflect the process of change undergone by immigrants is discussed. Although these terms have been used interchangeably, the outcome of change is very different in each. The difference between assimilation and acculturation is reflected in the models of adaptation regrouped under linear and bidimensional models. A 3rd model, called orthogonal cultural identification, is presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Tracheobronchial ruptures in closed thoracic trauma

Authors refer about their experience on five cases of thoracic trauma. Following a review of international literature, they analyze the clinical, diagnostic and therapeutic aspects of this kind of injuries.     

Sulfur containing polymers

Summary Copolymers containing -S-CO-S-and/or -O-CO-S-groups have been synthesized mainly by interfacial polycondensation.Different chemical structures were obtained by reacting 1,3-benzene dithiol (BDT) respectively with phosgene alone, phosgene and bisphenol-A (BPA), bischloroformate of BPA, BPA polycarbonate oligomers and by reacting phosgene with the products of BPA polycarbonate degraded with BDT. The chemical structures of the copolymers were investigated by IR, ¹H-NMR and ¹³C-NMR; molecular weights were determined by viscometry and vapor pressure osmometry. Although no attempt was made to find the optimum conditions for high molecular weight, some copolymers with fairly high mol. weight were obtained.     

Sol–Gel Processing and Microwave Characteristics of Ba(Mg⅓Ta⅔)O3 Dielectrics

The sol–gel method has been developed for the preparation of pure Ba(Mg_1/3Ta_2/3)O₃ ceramics. This involves the reaction of the heterometallic alkoxide Ta₂Mg(OEt)₁₂ with hydrated barium hydroxide Ba(OH)₂·8H₂O. Complete crystallization of the sol–gel-derived powder is achieved at 600°C, leading to a cubic perovskite type phase. After sintering at 1400°C (2–5 h), a trigonal cell arises from Mg–Ta ordering (the degree of order is greater than 0.9), and about 98.5% of the theoretical density is obtained. Preliminary microwave dielectric measurements show that the dielectric constant and the unloaded Q _u of the ceramics are 24.2 and 6750, respectively, at 7.7 GHz.     

Copyright Infringement and Protection in the Internet Age

In this age of increasingly complex, Internet-based technologies, it's very difficult to protect original works of authorship. This article examines the problem of copyright infringement and the copyright law's desire to balance the interests of creators with the interests of the public. The author also offers some insight in how to reduce the problem of copyright infringement.     

Detection of Partial Denaturation in AT-Rich DNA Fragments by Ion-Pair Reversed-Phase Chromatography

Temperature-dependent denaturation of DNA restriction fragments from the pBR322 plasmid ranging in length from 46 to 910 base pairs was detected by ion-pair reversed-phase high-performance liquid chromatography using columns packed with alkylated nonporous poly(styrene/divinylbenzene) particles. The presence of acetonitrile in the mobile phase was found to decrease the melting temperatures of DNA fragments by 1.5-2 °C/% of acetonitrile in the eluent. Small fragments (<120 bp) were completely denatured between 53.6 and 63.5 °C, depending on their total GC content. Whereas retention times of completely helical DNA fragments increased gradually with increasing temperature, partial denaturation of larger DNA fragments (>150 bp) was found to reduce retention at temperatures above 53.6 °C. Therefore, micropreparative fractionation and rechromatography, together with DNA restriction analysis, were applied to identify the correct elution order of completely helical and partially denatured fragments. Inspection of the DNA sequences of partially denatured fragments revealed domains with repeating AT base pairs. Positions of partial denaturation within the pBR322 plasmid detected by chromatographic analysis were in good agreement with partial denaturation maps obtained by electron microscopy desrcibed in the literature.     

Raising chickens for increased egg consumption in a rural highland Bolivian population

In highland Bolivia a three-year nutrition-sensitive agricultural intervention was carried out with rural families in which chicken rearing was promoted in order to increase egg consumption. Here we report on the impact of the intervention on participants’ diets. The non-randomized intervention took place in 21 rural communities in the province of Tapacarí in the department of Cochabamba, Bolivia. Intervention communities had staggered start times, with two communities starting in 2013, three communities starting in 2014 and sixteen communities starting in 2015. Twenty-four hour dietary recall data were collected from all individuals in 22 households in two communities in February/March 2013, 33 households in three communities in February/March 2014, and 66 households in fourteen communities in February/March 2015. We tested for changes from 2013 to 2014 to 2015 in consumption of 10 food groups in children under 6 years, adult men and adult women. By endline, egg production was established in ~80% of the intervention households. From baseline to endline egg consumption increased to approximately one-half egg/person/day: in children from 7 to 33 g/day, in women from 6 to 33 g/day, and in men from 6 to 39 g/day. Despite the increased intake in eggs, intake of most nutrients did not change. Higher egg consumption would be required to produce observable average increases in nutrient intake.     

Synthesis and analysis of phase segregation of polystyrene-block-poly(methyl methacrylate) copolymer obtained by Steglich esterification from semitelechelic blocks of polystyrene and poly(methyl methacrylate)

Here, an alternative route to successfully synthesize polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) is reported. Steglich esterification was used as an effective, metal free approach for coupling carboxylic terminated PS and the hydroxyl end-functionalized PMMA chains obtained by nitroxide-mediated polymerization and atom transfer radical polymerization, respectively. α-Functionalization was obtained using 4,4′-azobis(4-cyanovaleric acid) and 2,2,2-tribromoethanol as initiators. The synthesis of PS-b-PMMA was confirmed by gel permeation chromatography and nuclear magnetic resonance (NMR), while the dependence of the diffusion coefficients of the polymers (PS, PMMA, PS/PMMA blend, and PS-b-PMMA) with their corresponding molecular weights was discussed based on the results of atomic force microscopy-based infrared spectroscopy, differential scanning calorimetry, and spectra of diffusion-ordered NMR spectroscopy. Differently from PS-b-PMMA, a partial segregation was observed for the PS/PMMA blend, affecting its thermal behavior and diffusion coefficient. The study here presented provides an easier and efficient strategy for the synthesis of PS-b-PMMA and new insights into the diffusion of polymers.     

Hydrolytic stability of terephthaloyl chloride and isophthaloyl chloride

The phthaloyl chloride isomers, terephthaloyl chloride (TCl) and isophthaloyl chloride (ICl), are high production volume chemicals used in polymers to impartflame resistance, chemical resistance, and temperature stability and as water scavengers. In these studies, we determined the hydrolytic stability of TCl and ICl and their hydrolysis products in aqueous solutions. Hydrolysis rates for TCl and ICl were initially determined by gas chromatography/flame ionization detection in water buffered at pH 4.0, 7.0, and 9.0 and 0 degrees C for up to 30 min. Subsequent studies determined the products from TCl and ICl hydrolysis. The parent phthaloyl chlorides (TCl and ICl), their intermediate hydrolysis products (designated as the "half-acids"), and their stable hydrolysis products (terephthalic acid (TPA) and isophthalic acid (IPA)) were determined by high-performance liquid chromatography. The half-lives (t(1/2)) of TCl and ICl ranged from an average of 1.2 to 2.2 min and from 2.2 to 4.9 min, respectively, at pH 4-9 and 0 degrees C. The observed first-order rate constants (k(obs)) ranged from an average of 530 to 1100 (x 10(5) s(-1)) for TCl and 240 to 520 (x 10(5) s(-1)) for ICl. Both phthaloyl chlorides formed their respective short-lived intermediates, in which one of the two carboxylic acid chloride functionalities reacts with water to form the carboxylic acid ("half-acid"). Subsequently, the half-acids underwent further hydrolysis so that greater than 90% of the initial phthaloyl chloride hydrolyzed in less than 60 min at 0 degrees C. The hydrolysis products TPA and IPA were hydrolytically stable, undergoing no further transformations after 20 min at pH 7 and 25 degrees C. This work demonstrated that TCl, ICl, and their respective half-acids will not be persistent in aqueous systems for a time sufficient to have a sustained toxicological effect on aquatic organisms (less than 1 h). Performing additional aquatic toxicity studies, biodegradation studies, and potentially mammalian studies on TCl and ICl are unnecessary since the existing information on TPA and IPA with the hydrolysis data presented here is sufficient to address questions on the fate and effects of these two substances in aqueous environments.     

Crop yield after 5 decades of contrasting residue management

Nutrient Cycling in Agroecosystems - The benefits of soil organic input on crop yields have long been discussed, yet details of their relationship remain controversial. This study considers the...