Factors predicting continued high-risk behavior among gay men in small cities: Psychological, behavioral, and demographic characteristics related to unsafe sex.

Nearly 6,000 men entering gay bars in 16 small American cities were anonymously surveyed to assess their sexual behavior and to determine predictors of risky sexual practices. Excluding individuals in long-term exclusive relationships, 27% of the men reported engaging in unprotected anal intercourse in the past 2 months. Factors strongly predictive of risk included having a large number of different male partners, estimating oneself to be at greater risk, having weak intentions to use condoms at next intercourse, believing that safer sex is not an expected norm within one's peer reference group, being of younger age, and having less education. These findings indicate that HIV prevention efforts are urgently needed for gay men in smaller cities, with efforts particularly focused on young and less educated men sexually active with multiple partners. Prevention should focus on strengthening intentions to change behavior and on changing social norms to foster safer sex. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of controlled rearing on the development of stimulus-seeking behavior in rats.

Three experiments compared the performance of 272 differentially reared Long-Evans rats at 15–90 days of age in a situation in which the amount of self-exposure to various lighted displays was being measured. The kind of visual array preferred by these Ss was significantly influenced by both their ages and visual stimulation histories. Preference for light arrays involving features significantly increased in the case of light-reared and bias-reared Ss beginning at 60 days of age. At the same time, a preference for diffuse light stimulation emerged in the case of their dark-reared (DR) controls. Although the significant increase in light-seeking exhibited by all groups of Ss at 60 days of age was found to be unrelated to previous testing in the situation, the visual experience associated with repeated tests did "protect" DR Ss from the decline in light-seeking observed after prolonged visual deprivation. Potential species differences and the nature and specificity of these changes in visual behavior are further discussed with respect to the role of early experience in visual development. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nanocrystalline zeolite A: synthesis, ion exchange and dealumination

Zeolite A (LTA) with crystal sizes smaller than 100 nm was synthesized on a larger scale using tetramethylammonium hydroxide as templating agent. The samples were characterized by X-ray powder diffraction, elemental analysis and nitrogen adsorption. After calcination, the n_Al/(n_Al+n_Si) ratio was between 0.40 and 0.38 (n_Si/n_Al RATIO=1.5–1.6). In contrast to microcrystalline zeolite Na-A with n_Al/(n_Al+n_Si)=0.50 (n_Si/n_Al=1.0), the pore system of the sodium-exchanged nanocrystalline material (n_Al/(n_Al+n_Si)=0.40, n_Si/n_Al=1.5, n_Na/n_Al=0.80) was accessible to nitrogen at −196 °C, and a pore volume of 0.31 cm³ g⁻¹ was determined. However, the maximum loading could not be enhanced by exchange with bivalent cations (Ca²⁺ or Mg²⁺) as observed with microcrystalline zeolite A. The nanocrystalline zeolite A was dealuminated at the outer surface by post-synthesis treatment with ammonium hexafluorosilicate. The aluminum content n_Al/(n_Al+n_Si) could be decreased to a value of 0.29 (n_Si/n_Al=2.5) but this was accompanied by a considerable loss of the crystallinity.     

Predicting conduct problems: Can high-risk children be identified in kindergarten and Grade 1?

Externalizing behavior symptoms (EBS) in childhood are a strong predictor of future conduct problems. This study evaluated their predictive accuracy using logistic regression and receiver operating characteristic curve techniques. EBS, alone and in combination with other child and familial risk factors, were used to predict conduct problems 30 months later in a nonclinic population of kindergartners and Grade 1 children. The sensitivity (Sn) and positive predictive value (PPV) of EBS alone were below preset criteria of ≥50% for each (prevalence ≤15%). Sn and PPV increased when other child and familial factors were combined with symptoms but did not exceed the preset criteria. From a developmental perspective, substantial stability of EBS exists over time. However, from the perspective of prevention science, significant levels of misclassification will occur when EBS are used to designate high-risk status under the low-prevalence conditions of normal populations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Producing a high-quality synthetic steamcracker feedstock from different aromatic model components of pyrolysis gasoline on bifunctional zeolite catalysts

Aromatics with 6–9 carbon atoms, i.e., model components of pyrolysis gasoline, are hydroconverted on bifunctional Pd/H-ZSM-5 zeolites into a high-quality synthetic steamcracker feedstock (consisting mainly of ethane, propane and n-butane). The yield of these desired n-alkanes with two or more carbon atoms depends strongly on the nature of the aromatic feed: at 400 °C and 6 MPa in an excess of hydrogen, a yield of 72.8% is observed with toluene, but yields higher than 90% can be achieved with benzene or ethylbenzene as feed. These pronounced differences are rationalized in terms of varying types of classical β-scission and different contributions of non-classical Haag–Dessau cracking.     

In vitro antioxidant and anti-inflammatory effects of brewers' spent grain protein rich isolate and its associated hydrolysates

Brewers' spent grain (BSG) is a protein-rich by-product of the brewing industry. The present study examined the in vitro bioactivity of a BSG protein enriched preparation and its associated enzymatic hydrolysates (assigned A–J). Cytotoxicity was measured using the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) MTT assay in U937 and Jurkat T cells. IC₅₀ values were lower in the U937 cell line, ranging from 4.93 to 9.27% v/v versus a range of 4.11% v/v to undetectable in Jurkat T cells. The superoxide dismutase (SOD) and comet assays were performed on U937 cells pre-incubated with test samples and subsequently exposed to an oxidant. Hydrogen peroxide (H₂O₂) significantly reduced SOD activity by 37.7% and none of the test samples provided protection. None of the samples protected against DNA damage induced by tert-butylhydroperoxide (t-BOOH); hydrolysate H, prepared with Alcalase at 60 °C, protected against H₂O₂-induced DNA damage. The total phenolic content (TPC) was found to range from 0.021 to 0.055 mg GAE/mg dry powder. The effect of the BSG-derived test samples on cytokine production (IL-2, IL-4, IL-10, IFN-γ) in Concanavalin A (conA) stimulated Jurkat T cells was measured using an enzyme linked immunosorbent assay (ELISA). The samples had no effect on IL-2 and IL-4 production. The unhydrolysed sample C significantly reduced IL-10, while the protein rich isolate, unhydrolysed control samples and hydrolysates D, E, F, and J significantly reduced IFN-γ production. The BSG preparations possess little antioxidant potential and exhibit selective immunomodulatory effects that may be of benefit in the control of inflammatory diseases.     

The Control of Feather Pecking by Serotonin.

Feather-pecking behavior in laying hens (Callus gallus) may be considered a behavioral pathology, comparable to human psychopathological disorders. Scientific knowledge on the causalion of such disorders strongly suggests involvement of the serotonergic (5-hydroxytryptamine; 5-HT) system in feather pecking. Previously, chicks from a high-feather-pecking (HFP) line were found to display lower 5-HT turnover levels than chicks from a low-feather-pecking (LFP) line (in response to acute stress; Y. M. van Hierden et al., 2002). The present study investigated whether low 5-HT neurotransmission modulates feather pecking. First. S-15535, a somatodendritic 5-HT1A autoreceptor agonist, was demonstrated to be an excellent tool for reducing 5-HT turnover in the forebrain of LFP and HFP chicks. Second, the most effective dose of S-15535 (4.0 mg/kg body weight) significantly increased severe feather-pecking behavior. The results confirmed the postulation that the performance of feather pecking is triggered by low 5-HT neurotransmission. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reversible Conductive Inkjet Printing of Healable and Recyclable Electrodes on Cardboard and Paper

Conductive inkjet printing with metal nanoparticles is irreversible because the particles are sintered into a continuous metal film. The resulting structures are difficult to remove or repair and prone to cracking. Here, a hybrid ink is used to obviate the sintering step and print interconnected particle networks that become highly conductive immediately after drying. It is shown that reversible conductive printing is possible on low‐cost cardboard samples after applying standard paper industry coats that are adapted in terms of surface energy and porosity. The conductivity of the printed films approaches that of sintered standard inks on the same substrate, but the mobility of the hybrid particle film makes them less sensitive to cracks during bending and folding of the substrate. Damages that occur can be partially repaired by wetting the film such that particle mobility is increased and particles move to bridge insulating gaps in the film. It is demonstrated that the conductive material can be recovered from the cardboard at the end of its life time and be redispersed to recycle the particles and reuse them in conductive inks.     

Location of navigation menus in websites: an experimental study with Arabic users

While Arabic users represent by far the fastest growing language population on the Internet, research about how the peculiarities of Arabic language may shape users’ web interactions is still scarce. The preferences of Arabic users for menu location in websites have been studied. Two competing arguments have been proposed regarding the best location of menus in websites: conventional design (navigation menu should be placed on that side where users expect it based on previous experience) and reading direction (navigation menu should be placed on that side where readers are used to start off reading, so that the navigation menu is likely to be attended first). In an experiment, twenty-five participants with Arabic as mother language (who also spoke English) were briefly presented with screenshots from websites presented in Arabic or English and with menus located either on the left or the right, and rated their perceived visual appeal, usability, and trustworthiness. Results showed that participants judged the Arabic websites more positive when menus were located in the right- rather than in the left-hand side. In contrast, no differences for menu location were observed for English websites. These results are discussed in light of the conventional design and reading direction hypothesis and with regard to their implications for the design of Arabic websites.