Distributions of GABAA, GABAB, and benzodiazepine receptors in the forebrain and midbrain of pigeons

The single-stranded DNA parvoviruses occur in humans and many species of animals. In general, they are species-specific and capable of producing disease at any stage of life. Parvoviruses have a requirement to replicate in cells in a permissive S-phase of DNA mitosis. The infections may be cytolytic to select cell groups resulting in specific developmental defects or may produce more generalized effects such as anemia, pancytopenia, or hemorrhage. The fetus is at particular risk for damage because of the vast number of cells in active mitosis. The teratogenic effects may be severe, often resulting in fetal death. Infections in childhood and adulthood are more frequently mild to subclinical. Some of the teratogenic effects recognized in animal species have been identified in humans. With increased knowledge of parvovirus effects in animals, more pathogenic effects may be related to human parvoviral disease. The need for vaccination, currently used annually in many domestic animal species, continues to be evaluated for humans.     

Low particulate type IV phosphodiesterase activity in hypothyroid rat atria

Rats were made hypothyroid by adding propylthiouracil (PTU) to their drinking water. Some of the PTU-treated rats were given thyroid hormone injections for 5 days. Both soluble and particulate cAMP-phosphodiesterase activities of adipose and ventricular tissues were increased by 25-60% in hypothyroidism. In left atria, soluble cAMP-phosphodiesterase activity was not significantly altered in hypothyroidism, while total particulate cAMP-phosphodiesterase activity was lowered by 30%. This lowering was due to diminished isoenzyme IV activity, as studied with the isoenzyme-specific inhibitors rolipram and SK&F 94836. In conclusion, the present results show decreased particulate type IV cAMP-phosphodiesterase activity in hypothyroid rat atria. This may explain the increased responsiveness to isoproterenol in hypothyroid atria.     

Comments on "Evaluation of interactions of electric fields due to electrostatic discharge with human tissue"

Attention is drawn to recent paper by Rogers et al. (Aug., 2004) in which ultra-wideband pulses are applied to an isolated muscle as part of deriving a strength-duration curve for threshold stimulation. The paper extends the strength-duration threshold curve for unipolar pulses down to a pulse duration of about 1 ns, on the order of 1000 times shorter than previously studied. Results of the work justify use of traditional mathematical models of the strength-duration curve for nanosecond pulses, as done recently for the electric field resulting from electrostatic discharge through the body (Dawson, et al., 2004).     

A Distribution-Free Bayesian Approach for Determining the Joint Probability of Failure of Materials Subject to Multiple Proof Loads

Survival of manufacturing materials or component parts may depend on two or more variables, and yet joint strength tests can be difficult to perform. For many such materials, multiple strength properties can be estimated only using destructive testing. This problem gives rise to a technique called proof loading—stressing units up to a prescribed load, destroying only the weaker units, and leaving the survivors for further tests. We propose a distribution-free Bayesian approach for estimating the probability of joint failure under two proof loads. Our method does not assume that proof-load survivors are undamaged.     

The History and Collections of the Department of Mineralogy

Visitors to the November Munich Show will want to allow extra days to see these notable collections in Norway and Denmark.     

Application of elemental microanalysis to elucidate the role of spherites in the digestive gland of the helicid snail Chilostoma lefeburiana

In this case study we present an application of different analytical electron microscopic methods in biology, to elucidate their usefulness in such investigations. Using analytical electron microscopy, spherites in the digestive gland cells of the helicid snail Chilostoma lefeburiana were examined at three stages: just before the non-feeding period of over-wintering in November, in the middle of over-wintering in February and at its end in March. A detailed characterization of changes in the elemental composition of the spherites was characterized by a combination of transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy (EDXS), electron energy-loss spectroscopy (EELS) and energy filtering TEM (EFTEM). During over-wintering, the spherites passed the following changes. Before over-wintering in November, they consisted of striking concentric layers of electron-dense and electron-lucent zones, while in February and March they showed clear empty zones between materials of different electron density. In November spherites, C, O, Ca, P, Cl, Fe, Si, Na, K, Mg and S were detected, whereas in February ones C, O, N, Cl, Si and S were found and only C, O, N, Si and Cl were detected in March spherites. It is suggested that the elements missing in February and March were used in different physiological processes during over-wintering, like (1) the maintenance of the appropriate elemental composition of the internal environment, (2) accumulation of non-toxic waste materials that cannot be metabolized and (3) avoiding potential intoxication by contamination with toxic metals.     

Hybridity in the housing sector: examining impacts on social and private rented sector tenants in Scotland

Abstract

Housing Associations in many countries exhibit increasing levels of ‘hybridity’, as reductions in state financing for social housing, exacerbated by austerity policies since the 2008 crash, have instigated ‘enterprising’ approaches to maintaining income. Alongside this, hybrid organisations have emerged in the Private Rented Sector (PRS), responding to sectoral growth and consequent increases in vulnerable households entering private renting. These developing hybridities have been considered at a strategic level, but there has been little exploration of the impacts on tenants. This article examines two organisations, operating across the social and private rented sectors, to elucidate potential implications for tenants. The research suggests that different forms of hybridity can affect tenant outcomes and, moreover, that examining such impacts is important in understanding hybridity itself. Furthermore, the study suggests that emerging forms of hybridity, particularly in the PRS, may be blurring the boundaries between housing sectors, with implications for policy and research.     

Extraordinary behaviour of the Y1?xPrxBa2Cu3O7?δ system

Investigations of Y_1–x M _x Ba₂Cu₃O_7– (M=Ce, Th)c-axis oriented thin film specimens show that the rate of depression ofT _c withx is larger for M=Th, than for M=Ce and Pr, and suggest that Ce, like Th, is tetravalent in this compound. Hall effect measurements on Y_1–x Pr _x Ba₂Cu₃O_7– single crystals reveal aT ² dependence of the cotangent of the Hall angle in the normal state and a negative Hall anomaly belowT _c in the superconducting state, in agreement with recent reports. Our research shows that the depth, , of the negative Hall signal scales withT/T _c and that the maximum value of decreases linearly withx and vanishes atx0.24. Magnetoresistance measurements on Y_1–x Pr _x Ba₂Cu₃O_7– single crystals indicate that the irreversibility lineH(T ^*) obeys a universal scaling relation characterized by anm=3/2 power law nearT _c, with a crossover to a more rapid temperature dependence of belowT/T _c 0.6, similar to that observed for polycrystalline specimens.