Housing subsidies and income distribution

While housing subsidy programmes directed through government budgets have become more highly focused on those in need, indirect subsidies operating through the taxation and financial systems have become greater during the inflationary period, and have generally been directed towards those with higher incomes. The Housing Subsidies Study identified several hundred housing assistance programmes in Australia, and after aggregating these to manageable proportions, estimated income distributions for the recipients of each programme.     

980-nm pump-band wavelengths for long-wavelength-band erbium-dopedfiber amplifiers

The impact of pump wavelength and input signal power on the output signal and backward spontaneous emission noise power of L-band erbium-doped fiber amplifiers is examined. It is shown experimentally that tuning the pump wavelength ±30-nm away from the 980-nm absorption peak provides 3-5-dB improvement in pump-to-signal conversion     

Melatonin administration does not affect isoproterenol-induced LVH.

Left ventricular hypertrophy (LVH), a common sequella of hypertension, is associated with increased incidence of sudden cardiac death. The study reported herein measured the effect of melatonin on the heart in the setting of direct cardiac myocyte stimulation with isoproterenol, thus minimizing the role of autonomic output from the suprachiasmatic nucleus (SCN) and clarifying the effect of melatonin on LVH, an outcome of chromic hypertensions. Results show that daily injections of high dosages of melatonin do not affect heart weight:body weight or heart weight:tibia length ratios in the setting of isoproterenol-induced hypertrophy, suggesting that the cardiovascular effects of melatonin observed by others are not due primarily to a direct effect of melatonin on cardiac myocytes but to another mechanism, possibly melatonin modulation of SCN output. Melatonin has no effect on isoproterenol-induced LVH, suggesting that its cardiovascular effects are not due to a direct effect on cardiac myocytes. Melatonin has been found to have a significant effect on hypertension; however, in this study, one effect of extended hypertension, cardiac hypertrophy, which can ultimately lead to cardiac failure, was not affected, even by very large doses of melatonin in a chemically induced hypertrophy mouse model. It has been suggested that the effect of melatonin on hypertension is comparable to common antihypertensive agents.     

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.     

Age-related changes in septal serotonergic, GABAergic and glutamatergic facilitation of retention in SAMP8 mice

SAMP8/TaJf(P8) mouse strain has an inherited age-related impairment of learning and memory with its onset relatively early in its lifespan. Previously, it was reported that cholinergic and glutamatergic drugs injected into the hippocampus after behavioral training showed considerable shifts in the dose that improved retention in mice at 12 compared to 4 months of age. Cholinergic neurons in the septum supply most of the acetylcholine released in the hippocampus. In the present study, we determined if altered functional status of neurotransmission in the septum might account for the decrease in cholinergic and glutamatergic activity in the hippocampus of older SAMP8 mice. After training on footshock avoidance, P8 mice received a drug injection into the septum. Retention was tested 1 week later. The results indicate that bicuculline, GABA-A, and saclofen, GABA-B, receptor antagonist had to be injected at a higher dose in 12- than in 4-month-old mice to improve retention. The serotonergic antagonists, ketanserin and methiothepin, both showed dose response shifts such that less drug was needed to improve retention in 12- as compared to 4-month-old mice. It required four times more L-glutamate to improve retention in 12- than in 4-month-old mice. Agonists for acetylcholine, dopamine and norepinephrine receptors or an opiate antagonist required little or no change in the dose needed to improve retention in older P8 mice. SAMP8 mice may show an age-related impairment of septohippocampal functioning.     

Responses to ergometer exercise in a healthy biracial population of children

To determine normal values for the exercise variables heart rate, blood pressure, maximal workload, physical working capacity index, J point displacement, and ST segment slope, we stress tested 405 healthy children. We analyzed the data for four body surface area-determined groups, to discover whether there were any racial differences between healthy white children and black children. There were numerous racial differences in blood pressure, maximal workload, and physical working capacity index; there were no differences in the heart rate values. The incidence of false-positive J point displacement was less than or equal to 3% when the PR isoelectric line method was used. The ST segment slope in healthy children was always greater than zero at maximal exercise. Thus, norms for exercise variables must be expressed in relation to both sex and race. The nomograms presented in this report provide an easy-to-use set of normative data for cycle ergometer stress testing in children.     

Proposed use of rearrangement in multiexchange telecommunication networks

Rearrangement of connections can eliminate blocking in switching networks in exchanges. It is proposed to apply this principle to trunks in multiexchange networks. It is shown for two simple networks that rearrangement eliminates blocking and provides a better grade of service than conventional automatic alternative routing. In more complex networks, rearrangement should enable fewer trunks to be provided.     

Stabilization of Accelerating Voltage under High-Intensity Beam Loading

The problem of fluctuating beam load in high-intensity cascade synchrotrons is discussed. A comparison is made of various methods of controlling rf system amplitude and phase fluctuations, with emphasis on feedback control as an economical method of stabilization. Equations describing performance are given, together with typical values for the 200 BeV machine at 3 × 1013 protons/pulse.