Insulin receptors and signal transduction proteins in the hypothalamo-hypophyseal system: a review on morphological findings and functional implications

Receptors for insulin are widely distributed in the brain and pituitary. The current hypothesis on receptor function in these regions points to a role of insulin as a mediator in the communication of the peripheral endocrine system with the brain via various steps of the neuroendocrine axis. Recent data demonstrate that receptor-positive neurons in the brain, i.e. in the hypothalamus, and secretory cells in the anterior pituitary gland possess specific proteins that are thought to be involved in key steps of post receptor signal transduction, in particular insulin receptor substrate-1 and phosphatidylinositol 3'-kinase (PI3k). PI3k is a critical enzyme of the intracellular signaling pathway that is activated by a number of receptor tyrosine kinases, including receptors for insulin and IGF-1. This information further completes the framework indicating in vivo activity of insulin receptors in central neuroendocrine cells and their involvement in one branch of several physiological mechanisms that control body metabolism and nutritional behaviour.     

Studies on electrodeposition and corrosion behaviour of a Ni–W–Co amorphous alloy

A ternary alloy Ni–W–Co was electrodeposited and operational parameters in relation to its corrosion resistance and deposition efficiency were optimized. A 2² full factorial design was successfully employed for experimental design analysis of the results. By means of response surface analysis, the statistical model identified the following operating conditions for obtaining corrosion resistant alloy: 60 mA/cm² current density, 70 °C temperature, 20 rpm cathode rotation and 8.0 pH. The alloy was deposited at 36% current efficiency, with an average composition of 70% Ni, 8% Co, 22% W and traces of boron and with E _corr −0.508 V and R _p 4.56 × 10⁴ Ohm. The deposit obtained under these conditions had an amorphous character and showed good adherence, high corrosion resistance and presence of nodules on its surface. Electrochemical corrosion tests verified that the Ni–W–Co alloy had better corrosion resistance than similarly electrodeposited Co–W amorphous alloy.     

Far-infrared detector based on HgTe/HgCdTe superlattices

HgTe/Hg_0.05Cd_0.95Te superlattices (SLs) were grown on (112)B oriented Cd_0.96Zn_0.04 Te substrates using molecular beam epitaxy (MBE). The SLs, consisting of 100 periods of 80-Å-thick HgTe wells alternating with 77-Å-thick Hg_0.05Cd_0.95Te barriers, were designed to operate as detectors in the far-infrared (FIR) region. Infrared absorption spectroscopy, high-resolution transmission electron microscopy (TEM), Hall effect measurements, and x-ray diffraction were used to characterize the superlattice layers. A series of annealing experiments were initiated to quantify the temperature-dependent interdiffusion of the HgTe wells and Hg_0.05Cd_0.95Te barriers and consequently their degradation, which shifts the absorption edges of the SLs to higher energies, since a high-temperature ex situ anneal is normally required in order to produce the p-type material required for a photovoltaic detector. Results from infrared absorption spectroscopy, TEM, and Hall effect measurements for the annealed samples are presented. A FIR SLs single-element photoconductive (PC) device was designed and fabricated. Both material characterization and device testing have established the applicability of the HgTe/Hg_0.05Cd_0.95Te SLs for the FIR region.     

Novel composite polymeric electrolytes with surface-modified inorganic fillers

Surface-modified inorganic powders were applied as additives to plain salt-in-polymer polymeric electrolytes in order to enhance their properties and make them applicable in all-solid-state Li-polymer primary and secondary cells. These fillers consisted of alumina and titania powders (coarse and nano-sized) with superacidic groups introduced onto their surface. Then they were added to low and high molecular weight poly(ethylene oxide) (PEODME 500 and PEO 4,000,000) together with lithium perchlorate (LiClO₄, lithium tetraoxochlorate(VII)). In this way several different composite electrolytes were obtained that exhibited excellent stability versus lithium metal electrode and high lithium transference number. Herein the preparation procedure is described and preliminary results given.     

Effects of labor contractions on catecholamine release and breathing frequency in newborn rats.

Plasma catecholamines in newborn rats (0-2 hr old) were analyzed following vaginal birth, cesarean section with simulated labor contractions, or cesarean section without labor contractions. Upon delivery, pups were exposed to key elements of the rat's natural birth process, that is, umbilical cord occlusion, tactile stimulation, and cooling. Only pups exposed to actual or simulated labor showed an immediate rise in norepinephrine and epinephrine. Initial postpartum respiratory frequencies were higher in vaginal than in cesarean delivered pups and, in all groups, inversely correlated with catecholamine titers, suggesting respiratory distress or transient tachypnea at lower catecholamine levels. These findings establish a rat model for analyzing effects of labor on neonatal adaptive response during the transition from prenatal to postnatal life. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Impact of Complainant Sexual History Evidence on Jurors' Decisions: Considerations From a Psychological Perspective.

Although Canada's sexual assault laws have undergone considerable modification and revision since the late 1970s and early 1980s, it has only been within the past decade that a "rape shield" protection has applied to the complainant's prior sexual conduct with the defendant. Although the admission of evidence concerning the complainant's prior sexual conduct with the defendant now receives legislative protection, it can still, under some circumstances, be admitted at trial. Specifically, if the trial judge determines that the evidence pertaining to the complainant's prior sexual conduct with the defendant is of significant probative value to a fact at issue (other than the complainant's consent or credibility) and that this value is not outweighed by any potential prejudicial effects, it may be admitted at trial. Drawing on psychological research investigating the role played by complainant/defendant relational history in people's evaluations of sexual assault, the current article critically examines the potential impact that this evidence may have on jurors' decisions in sexual assault trials. This review suggests that significant dangers are associated with its introduction at trial and also includes a discussion of the legal implications of these research findings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Infrared detection by Tl−Ba−Ca−Cu−O superconducting films

The response of polycrystalline Tl?Ba?Ca?Cu?O superconducting thin films on short laser pulses has been investigated for radiation between 10 μm and 500 μm wavelength. Fast signals with time constants less than 1 ns were observed for wavelengths longer than about 100 μm whereas for shorter wavelengths only a bolometric signal could be detected.     

Mathematics of marital conflict: Qualitative dynamic mathematical modeling of marital interaction.

This article presents a new nonstatistical mathematical approach to modeling marital interaction by means of nonlinear difference equations. The application made of this modeling process in this article is to generate theory in order to understand J. M. Gottman and R. W. Levenson's (1992) report of the ability of one variable derived from a balance view of marital interaction to predict marital dissolution in a prospective study. Parameters are introduced that reflect uninfluenced husband and wife set points, emotional inertia, and influence function. These parameters are subjected to various examinations of validity with other data that reflect patterns of marital interaction and the cascade toward marital dissolution. Results suggest the hypothesis that unstable marriages are characterized at Time 1 by a mismatch in husband and wife influence functions. The modeling method makes it possible to fit a couple's equations under one set of conditions, then to simulate the couple's interaction under different conditions, and then to conduct experiments to test the validity of these simulations. The method provides a new approach toward the building of theory in family psychology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related decrease of plasma testosterone in SAMP8 mice: replacement improves age-related impairment of learning and memory

Corticosterone increases with aging but pregnenolone, dehydroepiandrosterone, and testosterone decrease. The marked decrease in hormones that occurs with aging may contribute to the age-related deficit in learning and memory. Administration of these hormones after training was found to improve long-term memory processing in normal young mice. SAMP8 (P8) mice show an age-related loss of learning and memory for a variety of tasks whereas age-matched control mice of the closely related SAMR1 (R1) strain do not. In this study, we found an age-related decrease in serum testosterone levels of 71% between P8 mice 4 and 12 months of age, but only a 26% decrease between R1 mice of the same ages. The difference between the P8 mice was significant (p < 0.01) and the difference between the R1 mice was not. The decrease in testosterone in 12-month-old P8 mice was not accompanied by gross morphological change in the testes. A SC testosterone implant, sufficient to increase plasma testosterone levels to 414 +/- 25 ng/dl, alleviated impaired learning and memory of a foot shock avoidance task in P8 mice. Castration of 4-month-old P8 mice did not produce a deterioration in learning and memory, indicating that low levels of testosterone per se are not responsible for the impairment seen in 12-month-old P8 mice. This suggests that impaired cognitive functioning of the older P8 mice was due to an interaction of aging and reduced testosterone levels.