Reaction product imaging: the h + d2 reaction

The differential cross section for the H + D(2) --> HD + D reaction has been measured using a technique called reaction product imaging. In this experiment, a photolytically produced beam of hydrogen (H) atoms crossed a beam of cold deuterium (D(2)) molecules. Product D atoms were ionized at the intersection of the two particle beams and accelerated toward a position-sensitive detector. The ion images appearing on the detector are two-dimensional projections of the three-dimensional velocity distribution of the D atom products. The reaction was studied at nominal center-of-mass collision energies of 0.54 and 1.29 electron volts. At the lower collision energy, the measured differential cross section for D atom production, summed over all final states of the HD(v,J) product, is in good agreement with recent quasi-classical trajectory calculations. At the higher collision energy, the agreement between the theoretical predictions and experimental results is less favorable.     

Radar Image of Asteroid 1989 PB

Radar observations of the near-Earth asteroid 1989 PB, made shortly after its optical discovery, yield a sequence of delay-Doppler images that reveal it to consist of two distinct lobes that appear to be in contact. It seems likely that the two lobes once were separate and that they collided to produce the current "contact-binary" configuration.     

Behavioral responses to ecological disturbances influence predation risk for a capital breeder

Landscape Ecology - Predation-risk and ecological disturbance regimes can both influence behavioral decisions by prey, yet few studies have simultaneously considered responses to these ecological...     

Immersive landscapes: modelling ecosystem reference conditions in virtual reality

Landscape Ecology - Understanding the variability and dynamics of ecosystems, as well as their responses to climate or land use change, is challenging for policy makers and natural resource...     

Incorporating habitat suitability,landscape distance,and resistant kernels to estimate conservation units for an imperiled terrestrial snake

Landscape Ecology - Wildlife distributions are often subdivided into discrete conservation units to aid in implementing management and conservation objectives. Habitat suitability models,...     

The efficacy and tolerability of levetiracetam in pharmacoresistant epileptic dogs

Twenty-two dogs with idiopathic epilepsy which were pharmacoresistant to phenobarbitone and bromide were treated with levetiracetam as an add-on medication. Records of eight dogs were used retrospectively to determine a safe, efficient levetiracetam dosage. Fourteen dogs were entered into a prospective, open label, non-comparative study. After 2 months of levetiracetam oral treatment (10 mg/kg TID), 8/14 dogs responded significantly to the treatment and seizure frequency was reduced by 50%. In dogs that remained refractory, the dosage was increased to 20 mg/kg TID for 2 months. One further dog responded to levetiracetam treatment. Levetiracetam responders had a significant decrease in seizure frequency of 77% (7.9+/-5.2 to 1.8+/-1.7 seizures/month) and a decrease in seizure days per month of 68% (3.8+/-1.7 to 1.2+/-1.1 seizure days/month). However, 6/9 responders experienced an increase in seizure frequency and seizure days after 4-8 months continuing with the levetiracetam treatment at the last effective dosage. Levetiracetam was well tolerated by all dogs and sedation was the only side-effect reported in just one of the 14 dogs.