The competitive NMDA antagonist CPP protects substantia nigra neurons from MPTP-induced degeneration in primates

Degeneration of nigrostriatal dopaminergic neurons is the primary histopathological feature of Parkinson's disease. The neurotoxin MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) induces a neurological syndrome in man and non-human primates very similar to idiopathic Parkinson's disease by selectively destroying dopaminergic nigrostriatal neurons. This gives rise to the hypothesis that Parkinson's disease may be caused by endogenous or environmental toxins. Endogenous excitatory amino acids (EAAs) such as L-glutamate could be involved in neurodegenerative disorders including Parkinson's disease. We report in this study that the competitive NMDA antagonist CPP (3-((+/-)-2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid) protects nigral tyrosine hydroxylase (TH) positive neurons from degeneration induced by systemic treatment with MPTP in common marmosets. This indicates that EAAs are involved in the pathophysiological cascade of MPTP-induced neuronal cell death and that EAA antagonists may offer a neuroprotective therapy for Parkinson's disease

Integrated Focal Plane Arrays for Millimeter-wave Astronomy

We are developing focal plane arrays of bolometric detectors for sub-millimeter and millimeter-wave astrophysics. We propose a flexible array architecture using arrays of slot antennae coupled via low-loss superconducting Nb transmission line to microstrip filters and antenna-coupled bolometers. By combining imaging and filtering functions with transmission line, we are able to realize unique structures such as a multi-band polarimeter and a planar, dispersive spectrometer. Micro-strip bolometers have significantly smaller active volume than standard detectors with extended absorbers, and can realize higher sensitivity and speed of response. The integrated array has natural immunity to stray radiation or spectral leaks, and minimizes the suspended mass operating at 0.1 - 0.3 K. We also discuss future space-borne spectroscopy and polarimetry applications

Distillation Designs for the Lunar Surface

Gravity-based distillation methods may be applied to the purification of wastewater on the lunar base. These solutions to water processing are robust physical separation techniques, which may be more advantageous than many other techniques for their simplicity in design and operation. The two techniques can be used in conjunction with each other to obtain high purity water. The components and feed compositions for modeling waste water streams are presented in conjunction with the Aspen property system for traditional stage distillation. While the individual components for each of the waste streams will vary naturally within certain bounds, an analog model for waste water processing is suggested based on typical concentration ranges for these components. Target purity levels for recycled water are determined for each individual component based on NASA s required maximum contaminant levels for potable water Optimum parameters such as reflux ratio, feed stage location, and processing rates are determined with respect to the power consumption of the process. Multistage distillation is evaluated for components in wastewater to determine the minimum number of stages necessary for each of 65 components in humidity condensate and urine wastewater mixed streams

Cyanotic nephropathy and use of non-ionic contrast agents during cardiac catherization in patients with cyanotic congenital heart disease

Background: Chronic cyanosis with its associated rheologic changes is a known risk factor for glomerular nephropathy. Therefore, contrast-induced nephrotoxicity should be an important consideration for angiographers comparable to diabetics. On the other hand, progressions in diagnostic and interventional techniques have led to expanded indications and a more widespread use of x-ray contrast agents. The aim of this study was to investigate the risk of contrast-induced nephropathy in the small group of patients with cyanotic heart disease prior to surgical repair. Methods: We investigated 23 cyanotic patients with an oxygen saturation of 82 (50–92)%, age 25 (5–63) years, and 13 control subjects with atrial septal defect, age 37 (20–66) years. Blood viscosity was measured before and after cardiac catherization. Renal damage was evaluatated by selective analysis of urinary proteins and enzymes. Results: Before cardiac catheterization, 48% of the cyanotic patients had a moderate glomerulopathy. Cardiac catherization was performed with 3.0 (1.2 – 6.8) mls/kg non ionic contrast medium. Only one of the 23 patients (4.3%) with normal urinary analysis before cardiac catheterization showed renal damage, which involved tubular and glomerular function. Elevated blood viscosity in cyanotic patients was slightly reduced by the contrast. None of the acyanotic controls had contrast-induced nephropathy. Conclusions: The use of non-ionic contrast medium does not worsen cyanotic glomerulopathy. This finding may be due to the reduction of blood viscosity by the application of the contrast medium. The finding of contrast-induced nephropathy in one patient underlines the importance of monitoring renal function after cardiac catheterization

Predicting the response of a submillimeter bolometer to cosmic rays

Bolometers designed to detect. submillimeter radiation also respond to cosmic, gamma, and x rays. Because detectors cannot be fully shielded from such energy sources, it is necessary to understand the effect of a photon or cosmic-ray particle being absorbed. The resulting signal (known as a glitch) can then be removed from raw data. We present measurements using an Americium-241 gamma radiation source to irradiate a prototype bolometer for the High Frequency Instrument in the Planck Surveyor satellite. Our measurements showed no variation in response depending on where the radiation was absorbed, demonstrating that the bolometer absorber and thermistor thermalize quickly. The bolometer has previously been fully characterized both electrically and optically. We find that using optically measured time constants underestimates the time taken for the detector to recover from a radiation absorption event. However, a full thermal model for the bolometer, with parameters taken from electrical and optical measurements, provides accurate time constants. Slight deviations from the model were seen at high energies; these can be accounted for by use of an extended model

The external benefits of higher education

The private market benefits of education are widely studied at the micro level, although the magnitude of their macroeconomic impact is disputed. However, there are additional benefits of education, which are less well understood. In this paper the macroeconomic effects of external benefits of higher education are estimated using the “micro-to-macro” simulation approach. Two types of externalities are explored: technology spillovers and productivity spillovers in the labour market. These links are illustrated and the results suggest they could be very large. However, this is qualified by the dearth of microeconomic evidence, for which we hope to encourage further work

Transition-edge superconducting antenna-coupled bolometer

We report test results for a single pixel antenna-coupled bolometric detector. Our device consists of a dual slot microstrip antenna coupled to an Al/Ti/Au voltage-biased transition edge superconducting bolometer (TES). The coupling architecture involves propagating the signal along superconducting microstrip lines and terminating the lines at a normal metal resistor colocated with a TES on a thermally isolated island. The device, which is inherently polarization sensitive, is optimized for 140 GHz band measurements. In the thermal bandwidth of the TES, we measure a noise equivalent power of 2.0 × 10^(-17) W/√Hz in dark tests that agrees with calculated NEP including only contributions from thermal, Johnson and amplifier noise. We do not measure any excess noise at frequencies between 1 and 200 Hz. We measure a thermal conductance G ~5.5 × 10^(-11) W/K. We measure a thermal time constant as low as 437μs at 3μV bias when stimulating the TES directly using an LED

BICEP: a large angular scale CMB polarimeter

We describe the design and expected performance of BICEP, a millimeter wave receiver designed to measure the polarization of the cosmic microwave background. BICEP uses an array of polarization sensitive bolometers operating at 100 and 150 GHz to measure polarized signals over a 20 degree field of view with 1 degree resolution. BICEP is designed with particular attention to systematic effects which can potentially degrade the polarimetric fidelity of the observations. BICEP is optimized to detect the faint signature of a primordial gravitational wave background which is a generic prediction of inflationary cosmologies

Emergency hospital admissions and three-year survival of adults with and without cardiovascular surgery for congenital cardiac disease

AbstractObjective:This study determined the quantity and nature of emergencies leading to unscheduled hospital admissions of adults with congenital cardiac disease and their mid-term survival.ResultsDuring 1 year, 429 adults with congenital cardiac diseases were admitted 571 times, and 124 admissions (22%) of 95 patients (22%) were emergency admissions. Fifteen of the 95 patients were seen for the first time in 1 of the participating centers. The underlying anomalies were Fallot's tetralogy and pulmonary atresia (n = 26/7), univentricular heart after Fontan procedure (n = 25), atrial septal defect (n = 18), Eisenmenger syndrome (n = 12), complete transposition (n = 11), and others (n = 25). Indications for admission were cardiovascular complications (n = 103; 83%) (arrhythmia, cardiac failure, syncope, pacemaker problems, pericardial tamponade, and sudden death), infections (n = 8, 6%) (endocarditis, pacemaker infection, pneumonia, and cerebral abscess), acute chest pain (n = 7; 6%), and acute abdominal pain (n = 4; 3%). All patients required immediate emergency care, and 16 patients (17%) required urgent cardiovascular or abdominal surgery. Six patients died during the hospital stay. During a follow-up of 2.9 years (SD 0.8), 16 (18%) of the discharged patients died, and 2 additional patients underwent heart or heart-lung transplantation.ConclusionAdults with congenital cardiac disease often experience serious emergency situations with a high in-hospital and mid-term post-hospital mortality. Care given by physicians with special expertise is important in this specific group of patients