Multitemporal passive microwave mapping in MACHYDRO'90

MACHYDR0'90 was an experiment conducted in Pennsylvania in 1990 to study the synergistic use of remote sensors in multitemporal hydrologic studies. As part of this mission the pushbroom microwave radiometer was flown and used to produce brightness temperature maps. Verification studies and vegetation algorithms for mixed land cover areas are described     

Application of a general health policy model in the American health care crisis

There is near consensus that the US health care system requires reform. Only a quarter of the American public has faith in the current system. Health care was one of the major issues considered in the 1992 US presidential election and the search for innovative solutions has transcended administrations.     

Influence of dietary sodium bicarbonate on the potassium metabolism of growing dairy calves.

We evaluated the influence of supplemental dietary NaHCO3 on K metabolism of young dairy calves. Thirty-two Holstein and Jersey male and female calves were blocked at 56 to 70 d after birth according to breed, sex, and age and assigned randomly to a 2 x 2 factorial arrangement of dietary treatments for 8 wk: .4% K with 0% NaHCO3, .4% K with 2% NaHCO3, .6% K with 0% NaHCO3, and .6% K with 2% NaHCO3. Feed intake was not affected by dietary KCl or NaHCO3 supplementation, but average daily gain increased with increased K and tended to be reduced by dietary NaHCO3. Plasma K was elevated by increased dietary K but generally was unaffected by NaHCO3. Urinary Ca excretion appeared to be reduced by NaHCO3; urine pH increased with supplemental NaHCO3. Results indicate 1) the K requirement of the growing calf is between .40 and .55% of diet DM, 2) because urinary K excretion was elevated by dietary NaHCO3, the K requirement may be increased when the diet is supplemented with NaHCO3, and 3) average daily gain and plasma K are sensitive indicators of dietary K in the growing calf.     

Microsoft robotics studio: A technical introduction

Microsoft robotics studio (MSRS) was publicly released in December 2006 with the explicit goal of providing an industry software standard for robot control. To become a viable standard, several technical challenges needed to be solved. In this article, we examine the composition of MSRS, looking generally at its architecture and specifically at its solutions for concurrency, distribution, abstraction, simulation, and programmer interaction. We also examine briefly the emerging industry and academic adoption of the robotics studio.     

Oxidant damage to erythrocyte membrane in glucose-6-phosphate dehydrogenase deficiency: correlation with in vivo reduced glutathione concentration and membrane protein oxidation

Chronic nonspherocytic hemolytic anemia has been observed in a recently described glucose-6-phosphate dehydrogenase (G6PD) variant, G6PDWayne. The mechanical properties of these erythrocytes and other G6PD variants were examined. The deformability of G6PD-deficient erythrocytes was normal, as determined by osmotic scan ektacytometry, and was not significantly affected by hemolytic crisis. In the common varieties of G6PD deficiency, the mechanical stability of the red blood cell (RBC) membrane was greater than normal, but G6PDWayne membranes were abnormally susceptible to shear-induced fragmentation. There was no evidence for a concurrent genetic defect in spectrin, because self-association constants and tryptic digests were normal. The fragility of G6PDWayne membranes appeared to be a consequence of oxidative damage to membrane thiol groups associated with a low glutathione (GSH) level in these RBCs. Associations among GSH level, thiol oxidation, and membrane instability were also found when a larger group of G6PD-deficient RBCs were examined. In normal erythrocytes, 1-chloro-2,4-dinitrobenzene was used to reduce GSH levels by 50%. Membrane thiol oxidation and membrane fragility both increased when these cells were kept at 4 degrees C for 3 to 5 days. Our findings suggest that chronic depletion of GSH leads to the destabilization of membrane skeleton through oxidation of membrane protein thiols.     

Groupwork and computers: task type and children's performance

Abstract In the majority of British primary schools, children use the computer in groups of two or three. This is partly due to the lack of resources, that is, most classrooms still only have one or two computers to share between around 30 children. Groupwork on computers is also justified for pedagogic reasons. Previous research comparing children working in groups or alone has revealed an advantage for children working in groups although the work undertaken has generally been problem solving tasks. This investigation examined the performance of pairs and individual 6-year old children on a drill and practice program using a pre-test, intervention, post-test design. In comparison to the problem solving evidence, individuals were found to have a significant advantage over pairs during the computer-based task.     

Coherence coding for photonic code-division multiple accessnetworks

We analyze a code-division multiple access technique where information is optically encoded by manipulating the coherence between a pair of transmitted signals. Key features are intrinsic security, operation of the receiver at only the bit rate of a single channel, and reconfiguration without switching optical delays, which are considerable advantages compared to previously proposed CDMA schemes. Experimental results demonstrating the basic operation of the scheme are presented. The performance limitations are calculated and novel implementations are proposed     

DRY-RO membranes from cellulose acetate carbamates

Cellulose acetate carbamates (CACs) are the polymers which result when organic isocyanates are reacted with the free hydroxyl groups of cellulose acetate (CA). CACs are more hydrolytically stable and exhibit physical properties which are superior to those of their CA mixed ester analogs. Two synthetic approaches to CACs have been utilized in this study: (1) preformation, i.e., separate synthesis of such polymers prior to their inclusion in solutions for membrane casting; and (2) in situ formation, i.e., the inclusion of blocked isocyanates in standard dry process casting solutions of CA followed by thermal activation of the resultant dry membranes leading to regeneration of free isocyanate and subsequent CAC formation. Preformed CAC polymers have been prepared utilizing phenyl-, 3-chloropropyl-, 3-bromopropyl-, and 3-bromopropyl-(isothio)-, isocyanates. Polymers containing omega-halocarbamate moieties were quaternized with dimethylbenzylamine to produce ionogenic (QCAC) polymers containing quaternary ammonium groups. DRY-RO membranes from the QCACs exhibit flux/rejection values varying between 6–8 gfd at 98% rejection and 20 gfd at 90% rejection (0.5% NaCl feed at 400 psi and 25°C). In situ formation of CAC membranes has been effected with tolylene- and hexamethylene-diisocyantes, with quaternized isocyanate monomers employed for the preformed CAC polymers, and with specially tailored diisocyanates containing ionogenic groups. Crosslinking rendered all of the membranes acetone insoluble. Inasmuch as in situ formation substitutes the easy synthesis of blocked isocyanate monomers for the more difficult separate synthesis of preformed CAC polymers, it is anticipated that the former will replace the latter.