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)     

Properties of Wave Propagation in a Gel-type Belousov–Zhabothinsky Reaction under Micro-gravity

The Belousov–Zhabothinsky (BZ) reaction is a chemical reaction which exhibits spatial as well as temporal pattern formation. Being an excitable medium, it can be influenced by even small external forces. One of these small forces which under ground conditions permanently is given is gravity. The gravity dependence of the BZ-reaction has been investigated in some detail up to now, and it has been found that especially the propagation velocity of waves in thin layers of fluid BZ-medium depends significantly on gravity-amplitude and -orientation. This finding has been mainly assigned to an interaction of gravity with diffusion and convection in the medium at the wave front, and consequently it has been stated that the propagation of waves in gels of BZ-medium is not significantly gravity dependent. We have now done more detailed experiments and have been able to show that also in gels the propagation velocity of BZ-waves is altered by gravity, but less than in fluid systems. Experiments have been performed in a lab centrifuge, a sounding rocket experiment and a parabolic flight mission.     

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.     

Preovulatory rise of NGF in ovine follicular fluid: possible involvement in the control of oocyte maturation

Since nerve growth factor (NGF) is produced in vitro by granulosa cells after gonadotropin stimulation, the present research has been designed to investigate whether this neurotropin is involved in the events triggered by the gonadotropin surge that lead the follicle to ovulate a mature oocyte. To this aim, NGF levels in follicular fluid, collected before or 20 hours after the gonadotropin surge, was measured by ELISA. To evaluate whether NGF may have a non-neurotropic effect on follicle cells, the presence of NGF receptors was investigated by immunohistochemistry and further evaluated by analysing the tyrosine-phosphorylation pattern after NGF stimulation in vitro. The effect of NGF on the degree of cumulus expansion, cumulus-oocyte metabolic coupling, and meiotic maturation was finally studied by using the culture of follicle-enclosed oocyte. The results demonstrate that GnRH causes a dramatic rise of NGF in large follicles. Immunohistochemistry revealed a discrete positivity for trkA receptors localised in cumulus cells. Tyrosine phosphorylation pattern confirms that somatic cells are capable to transduce NGF signal. By contrast, all the oocytes examined were negative for trkA and did not change the phosphorylation pattern after NGF. In vitro NGF (100 ng/ml) induced a marked cumulus expansion and a progressive cumulus-oocyte uncoupling similar to that produced by gonadotropins. The addition of NGF also caused the resumption of meiosis in more than 70% of the oocytes analysed with an effect that is only slightly less pronounced than that of gonadotropins (80%). The increase in NGF secretion following gonadotropin surge suggests that this neurotropin may be involved in the control of oocyte maturation.     

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)     

Development and validation of the Neuropsychology Behavior and Affect Profile.

This series of 4 studies describes the psychometric properties of the Neuropsychology Behavior and Affect Profile, which consists of 5 peer-rated scales (106 items) designed to measure personality change in brain-impaired individuals. Study 1 pertains to item derivation. Study 2 used relatives of 61 Ss identified as demented to determine the test's internal consistency. Results showed moderate levels of internal consistency across the 5 scales, with slightly higher coefficients (.68–.82) obtained for present (vs. premorbid) emotional status. High test–retest reliability was demonstrated in Study 3 (intraclass correlation coefficients ranged from .92 to .99). Study 4 established discriminant validity; the instrument differentiated 61 demented Ss from 88 normal elderly controls on the basis of present behavioral affective style. (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.     

Rapid 3D Printing of Electrohydraulic (HASEL) Tentacle Actuators

A comprehensive material system is introduced for the additive manufacturing of electrohydraulic (HASEL) tentacle actuators. This material system consists of a photo‐curable, elastomeric silicone‐urethane with relatively strong dielectric properties (ε_r ≈ 8.8 at 1 kHz) in combination with ionically‐conductive hydrogel and silver paint electrodes that displace a vegetable‐based liquid dielectric under the application of an electric field. The electronic properties of the silicone material as well as the mechanical properties of the constitutive silicone and hydrogel materials are investigated. The hydraulic pressure exerted on the dielectric working fluid in these capacitive actuators is measured in order to characterize their quasi‐static behavior. Various design features enabled by 3D printing influence this behavior—decreasing the voltage at which actuation begins or increasing the force density in the system. Using a capacitance change of >35% across the actuators while powered, a demonstration of self‐sensing inherent to HASELs is shown. Antagonistic pairs of the 3D printed actuators are shown to exert a blocked force of over 400 mN. An electrohydraulic tentacle actuator is then fabricated to demonstrate the use of this material and actuation system in a synthetic hydrostat. This tentacle actuator is shown to achieve motion in a multi‐dimensional space.