Nonlinear flange curling in wide flange sections

The paper describes the experimental and theoretical analysis of flange curling deformations in wide flange sections. As distinct from previous analyses of flange curling, the paper considers the effect of cross-sectional deformations in the calculation of the cross-section stress distribution and the flange curling deformations. The deformations of the cross-section lead to changes in the second moment of area of the cross-section and its neutral axis, and the analysis is therefore iterative. It is shown that the effect of flange curling is to decrease the applied stress near the centre of the wide flange, which in turn increases the buckling capacity of the section. Of particular interest is the finding that while the stress distribution changes significantly, the final flange curling deformation is virtually the same whether obtained from an accurate iterative analysis or from a first-order linear analysis. This provides a simple improved method for determining the effects of flange curling, namely by determining the flange curling deformations from a first order analysis and accounting for them in determining the stress distribution.     

Development and evaluation of validity scales for the Neuropsychology Behavior and Affect Profile: A dissembling study.

The Neuropsychology Behavior and Affect Profile ( NBAP) is a peer-rated inventory of behavioral and affective changes in brain injured individuals and consists of five Clinical Scales that have demonstrated strong external validity. A potential confound is the NBAP's susceptibility to rater bias. In the present investigation, four validity scales were developed and external validity and psychometric properties were examined through a dissembling paradigm. Study1 describes item selection and construction of the validity scales. Study 2 demonstrates that various combinations of both the clinical and validity scales effectively differentiated dissemblers from informants of two groups of traumatic brain injury patients. Although results differed somewhat when dissemblers were grouped according to their level of neuropsychological training, highly trained dissemblers (licensed clinical neuropsychologists) could be detected. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Temperature modulates the production and activity of a metalloprotease from Pseudomonas fluorescens 07A in milk

This work evaluated the expression and activity of a metalloprotease released by Pseudomonas fluorescens 07A in milk. Low relative expression of the protease by the strain was observed after incubation for 12 h at 25°C while the strain was in the logarithmic growth phase. After 24 h, protease production significantly increased and remained constant for up to 48 h, a time range during which the strain remained in the stationary phase. Conversely, at refrigeration temperatures, at 12 h the strain was still in the lag phase and expressed the protease at higher levels than when the logarithmic phase was reached. Casein fractions were highly degraded by P. fluorescens 07A, the purified protease, and the bacterial pellet on d 7 of incubation at 25°C and to a lesser extent at 10°C for the sample incubated with the bacterium. Heat treatment at 90°C for 5 min completely inactivated the proteolytic activity of the purified protease and the bacterial pellet. This work contributes to the knowledge about the conditions of milk storage that influence the production and activity of this extracellular metalloprotease. The results demonstrate the need to find alternative strategies to control the synthesis and activity of proteolytic enzymes in the dairy industry to ensure the quality of processed products.     

Emerging Roles of the Iron Chelators in Inflammation

Iron is a crucial element for mammalian cells, considering its intervention in several physiologic processes. Its homeostasis is finely regulated, and its alteration could be responsible for the onset of several disorders. Iron is closely related to inflammation; indeed, during inflammation high levels of interleukin-6 cause an increased production of hepcidin which induces a degradation of ferroportin. Ferroportin degradation leads to decreased iron efflux that culminates in elevated intracellular iron concentration and consequently iron toxicity in cells and tissues. Therefore, iron chelation could be considered a novel and useful therapeutic strategy in order to counteract the inflammation in several autoimmune and inflammatory diseases. Several iron chelators are already known to have anti-inflammatory effects, among them deferiprone, deferoxamine, deferasirox, and Dp44mT are noteworthy. Recently, eltrombopag has been reported to have an important role in reducing inflammation, acting both directly by chelating iron, and indirectly by modulating iron efflux. This review offers an overview of the possible novel biological effects of the iron chelators in inflammation, suggesting them as novel anti-inflammatory molecules.     

Prenylcysteine Oxidase 1 (PCYOX1), a New Player in Thrombosis

Prenylcysteine Oxidase 1 (PCYOX1) is an enzyme involved in the degradation of prenylated proteins. It is expressed in different tissues including vascular and blood cells. We recently showed that the secretome from Pcyox1-silenced cells reduced platelet adhesion both to fibrinogen and endothelial cells, suggesting a potential contribution of PCYOX1 into thrombus formation. Here, we show that in vivo thrombus formation after FeCl₃ injury of the carotid artery was delayed in Pcyox1^−/− mice, which were also protected from collagen/epinephrine induced thromboembolism. The Pcyox1^−/− mice displayed normal blood cells count, vascular procoagulant activity and plasma fibrinogen levels. Deletion of Pcyox1 reduced the platelet/leukocyte aggregates in whole blood, as well as the platelet aggregation, the alpha granules release, and the α_IIbβ₃ integrin activation in platelet-rich plasma, in response to adenosine diphosphate (ADP) or thrombin receptor agonist peptide (TRAP). Washed platelets from the Pcyox1^−/− and WT animals showed similar phosphorylation pathway activation, adhesion ability and aggregation. The presence of Pcyox1^−/− plasma impaired agonist-induced WT platelet aggregation. Our findings show that the absence of PCYOX1 results in platelet hypo-reactivity and impaired arterial thrombosis, and indicates that PCYOX1 could be a novel target for antithrombotic drugs.     

Early detection of cognitive decline in higher cognitively functioning older adults: Sensitivity and specificity of a neuropsychological screening battery.

The sensitivity and specificity of a neuropsychological screening battery designed to determine early cognitive decline in the high functioning elderly are presented. The battery is composed of 4 standard neuropsychological tests assessing cognitive domains commonly effected in early stages of CNS disease. Initial validation data were gathered by applying cutoff scores derived from published or submitted normative data to test data on 2 groups of elderly, higher cognitively functioning individuals: a sample of 45 elderly individuals diagnosed with 1 of 5 target disorders, and a sample of 61 independent elderly. Cutoff scores were identified that produce high rates of correct classification and a range of sensitivity and specificity. The suggested neuropsychological test battery classifies Ss as having a high, moderate, or low probability of cognitive impairment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Survival in vitro and virulence of Trypanosoma cruzi in açaí pulp in experimental acute Chagas disease

Chagas disease is a parasitic infection with high socioeconomic impact throughout Latin America. Although this severe, incurable disease can be transmitted by several routes, oral transmission is currently the most important route in the Amazon Basin. A?aí pulp has nutritional properties and is popular throughout Brazil and abroad. However, this pulp has been associated with microepidemics of acute Chagas disease (ACD) in northern Brazil, where a?aí fruit is the main food supplement. In this study, we examined the in vitro survival and in vivo virulence of Trypanosoma cruzi Y strain in a?aí pulp. Aliquots of in natura a?aí pulp produced in Belém city in the northern Brazilian state of Pará were mixed with 10? trypomastigotes. The samples were incubated at room temperature or at 4 or -20°C for various periods, and the parasites were isolated by forced sieving. The resulting eluates were examined by microscopy, and the trypomastigotes were administered intraperitoneally, orally, or by gavage to immunodeficient mice (C.B-17-Prkdc(scid)/PasUnib) that had been pretreated with antibiotics. Parasitemia was quantified by the Brener method, and mortality was recorded daily. All routes of administration resulted in ACD. A 5-day delay in the onset of parasitemia occurred with oral administration. The survival and virulence of the parasites were unaffected by prior incubation at room temperature for 24 h, at 4°C for 144 h, and at -20°C for 26 h. These results indicate that T. cruzi can survive and retain its virulence in a?aí pulp under various conditions and that cooling and freezing are not suitable methods for preventing foodborne ACD.     

Measuring search efficiency in complex visual search tasks: Global and local clutter.

[Correction Notice: An erratum for this article was reported in Vol 17(2) of Journal of Experimental Psychology: Applied (see record 2011-11863-002). The copyright for the article was incorrectly listed. The copyright is in the correction.] Set size and crowding affect search efficiency by limiting attention for recognition and attention against competition; however, these factors can be difficult to quantify in complex search tasks. The current experiments use a quantitative measure of the amount and variability of visual information (i.e., clutter) in highly complex stimuli (i.e., digital aeronautical charts) to examine limits of attention in visual search. Undergraduates at a large southern university searched for a target among 4, 8, or 16 distractors in charts with high, medium, or low global clutter. The target was in a high or low local-clutter region of the chart. In Experiment 1, reaction time increased as global clutter increased, particularly when the target was in a high local-clutter region. However, there was no effect of distractor set size, supporting the notion that global clutter is a better measure of attention against competition in complex visual search tasks. As a control, Experiment 2 demonstrated that increasing the number of distractors leads to a typical set size effect when there is no additional clutter (i.e., no chart). In Experiment 3, the effects of global and local clutter were minimized when the target was highly salient. When the target was nonsalient, more fixations were observed in high global clutter charts, indicating that the number of elements competing with the target for attention was also high. The results suggest design techniques that could improve pilots' search performance in aeronautical charts. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Synergism and Performance for Systems Containing Binary Mixtures of Anionic/Cationic Surfactants for Enhanced Oil Recovery

The surfactant structure–performance relationship and application properties in enhanced oil recovery (EOR) for binary mixtures of anionic and cationic surfactants are presented and discussed. A polyoxyethylene ether carboxylate anionic surfactant was blended with a quaternary ammonium chloride cationic surfactant and tested for a high-temperature, low-salinity, and high-hardness condition as found in an oil reservoir. These mixtures were tailored by phase behavior tests to form optimal microemulsions with normal octane (n-C8) and crude oil having an API gravity of 48.05°. The ethoxy number of the polyoxyethylene carboxylate anionic surfactant and the chain length of the cationic surfactant were tuned to find an optimal surfactant blend. Interfacial tensions with n-C8 and with crude oil were measured. Synergism between anionic and cationic surfactants was indicated by surface tension measurement, CMC determination, calculation of surface excess concentrations and area per molecule of individual surfactants and their mixtures. Molecular interactions of anionic and cationic surfactants in mixed monolayers and aggregates were calculated by using regular solution theory to find molecular interaction parameters β ^σ and β ^M . Morphologies of surfactant solutions were studied by cryogenic TEM. The use of binary mixtures of anionic/cationic surfactants significantly broadens the scope of application for conventional chemical EOR methods.     

Rotamers in Crystal Structures of Xylitol,D-Arabitol and L-Arabitol

Rotamers are stereoisomers produced by rotation (twisting) about σ bonds and are often rapidly interconverting at room temperature. Xylitol—massively produced sweetener—(2R,3r,4S)-pentane-1,2,3,4,5-pentol) forms rotamers from the linear conformer by rotation of a xylitol fragment around the C2–C3 bond (rotamer 1) or the C3–C4 bond (rotamer 2). The rotamers form two distinguishable structures. Small differences in geometry of rotamers of the main carbon chain were confirmed by theoretical calculations; however, they were beyond the capabilities of the X-ray powder diffraction technique due to the almost identical unit cell parameters. In the case of rotamers of similar compounds, the rotations occurred mostly within hydroxyl groups likewise rotations in L-arabitol and D-arabitol, which are discussed in this work. Our results, supported by theoretical calculations, showed that energetic differences are slightly higher for rotamers with rotations within hydroxyl groups instead of a carbon chain.