Quantizations on the circle and coherent states

We present a possible construction of coherent states on the unit circle as configuration space. Our approach is based on Borel quantizations on S^1 including the Aharonov-Bohm type quantum description. The coherent states are constructed by Perelomov's method as group related coherent states generated by Weyl operators on the quantum phase space Z x S^1. Because of the duality of canonical coordinates and momenta, i.e. the angular variable and the integers, this formulation can also be interpreted as coherent states over an infinite periodic chain. For the construction we use the analogy with our quantization and coherent states over a finite periodic chain where the quantum phase space was Z_M x Z_M. The coherent states constructed in this work are shown to satisfy the resolution of unity. To compare them with canonical coherent states, also some of their further properties are studied demonstrating similarities as well as substantial differences.Comment: 15 pages, 4 figures, accepted in J. Phys. A: Math. Theor. 45 (2012) for the Special issue on coherent states: mathematical and physical aspect

Solar energy water desalination in the United States and Saudi Arabia

Five solar energy water desalination systems were designed to deliver 6000 cubic m/day of desalted water from either seawater or brackish water. Two systems will be selected for pilot plant construction. The pilot plants will have capacities in the range of 100 to 400 m/day. Goals of the Project Agreement for Cooperation in the Field of Solar Energy, under the auspices of the United States-Saudi Arabian Joint Commission on Economic Cooperation, are to: (1) cooperate in the field of solar energy technology for the mutual benefit of the two countries, including the development and stimulation of solar industries within the two countries; (2) advance the development of solar energy technology in the two countries; and (3) facilitate the transfer between the two countries of technology developed under this agreement

Specialized physiological studies in support of manned space flight

The effects of a diuretic (Lasix) induced dehydration on the cardiovascular and hematological responses to lower body negative pressure (LBNP) were analyzed and compared to previous observations on dehydration following exercise in the heat. During LBNP runs the subjects were monitored for changes in blood volume, heart rate, blood pressure, and variations in the volume of the left calf. It was concluded that Lasix dehydration produced a depletion of the body electrolytes at the expense of both the plasma and extravascular compartments. Striking differences were found between those subjects who were physically active (Runners: R) and those who did not engage in any regular physical activity (Non-runners: NR). Tolerance to LBNP (Torr x min) was significantly lower in the R's than the NR's before and after dehydration, however the R's lost more of their tolerance after dehydration with Lasix than after exercise in the heat for about the same fluid loss. The opposite was true for the NR's. Two factors appear to be responsible for the lower LBNP tolerance in R's: parasympathetic inhibition of cardiac activity during LBNP and a greater propensity to pool blood in the lower extremities

Coherent states on the circle

We present a possible construction of coherent states on the unit circle as configuration space. In our approach the phase space is the product Z x S^1. Because of the duality of canonical coordinates and momenta, i.e. the angular variable and the integers, this formulation can also be interpreted as coherent states over an infinite periodic chain. For the construction we use the analogy with our quantization over a finite periodic chain where the phase space was Z_M x Z_M. Properties of the coherent states constructed in this way are studied and the coherent states are shown to satisfy the resolution of unity.Comment: 7 pages, presented at GROUP28 - "28th International Colloquium on Group Theoretical Methods in Physics", Newcastle upon Tyne, July 2010. Accepted in Journal of Physics Conference Serie

Inhibition of Trophoblast-Induced Spiral Artery Remodeling Reduces Placental Perfusion in Rat Pregnancy.

Rats harboring the human angiotensinogen and human renin genes develop preeclamptic features in pregnancy. The preeclamptic rats exhibit a deeper trophoblast invasion associated with a reduced resistance index by uterine Doppler. Doxycycline inhibits matrix metalloproteinase activity. We tested the hypothesis that matrix metalloproteinase inhibition reduces trophoblast invasion with subsequent changes in placental perfusion. Preeclamptic and pregnant control Sprague-Dawley rats were treated with doxycycline (30 mg/kg of body weight orally) from gestational day 12 until day 18. Placental perfusion was assessed using a micromarker contrast agent. The animals were euthanized on day 18 of pregnancy; biometric data were acquired, and trophoblast invasion was analyzed. Doxycycline resulted in intrauterine growth retardation and lighter placentas in both groups. Maternal body weight was not affected. As shown earlier, preeclamptic rats exhibited a deeper endovascular trophoblast invasion. However, doxycycline treatment reduced trophoblast invasion in the preeclamptic rats. The physiological spiral artery remodeling, as assessed by the deposition of fibrinoid and α-actin in the spiral artery contour, was significantly reduced by doxycycline. The vascularity index, as assessed by perfusion measurement of the placenta, was reduced after doxycycline treatment in preeclamptic rats. Thus, matrix metalloproteinase inhibition with doxycycline leads to reduced trophoblast invasion and associated reduced placental perfusion. These studies are the first to show that reducing trophoblast-induced vascular remodeling decreases subsequent placental perfusion. Our model allows the study of dysregulated trophoblast invasion and vascular remodeling in vivo to gain important insights into preeclampsia-related mechanisms

Dihedral symmetry of periodic chain: quantization and coherent states

Our previous work on quantum kinematics and coherent states over finite configuration spaces is extended: the configuration space is, as before, the cyclic group Z_n of arbitrary order n=2,3,..., but a larger group - the non-Abelian dihedral group D_n - is taken as its symmetry group. The corresponding group related coherent states are constructed and their overcompleteness proved. Our approach based on geometric symmetry can be used as a kinematic framework for matrix methods in quantum chemistry of ring molecules.Comment: 13 pages; minor changes of the tex

Targeting kidney mesangium by nanoparticles of defined size

Nanoparticles are being investigated for numerous medical applications and are showing potential as an emerging class of carriers for drug delivery. Investigations on how the physicochemical properties (e.g., size, surface charge, shape, and density of targeting ligands) of nanoparticles enable their ability to overcome biological barriers and reach designated cellular destinations in sufficient amounts to elicit biological efficacy are of interest. Despite proven success in nanoparticle accumulation at cellular locations and occurrence of downstream therapeutic effects (e.g., target gene inhibition) in a selected few organs such as tumor and liver, reports on effective delivery of engineered nanoparticles to other organs still remain scarce. Here, we show that nanoparticles of ~75 ± 25-nm diameters target the mesangium of the kidney. These data show the effects of particle diameter on targeting the mesangium of the kidney. Because many diseases originate from this area of the kidney, our findings establish design criteria for constructing nanoparticle-based therapeutics for targeting diseases that involve the mesangium of the kidney

Light-chain-induced renal tubular acidosis: effect of sodium bicarbonate on sodium-proton exchange

We measured sodium-proton (Na+/H+) exchange in lymphocytes and platelets of a 46-year-old woman with the adult Fanconi syndrome before, during, and after treatment with NaHCO3. Kappa light chains in her urine and unique but rarely observed crystalline structures confirmed the presence of light-chain nephropathy. Her glomerular filtration rate was only moderately impaired at 72 ml/min. NaHCO3 at 1, 3, and 5 mmol/kg/day for 5 days increased her serum HCO3 and pH from 17 to 21 mmol/l and 7.28 to 7.39 respectively. Plasma renin and aldosterone values were decreased by NaHCO3. Na+/H+ exchange (δHi/min) was measured with the fluorescent marker BCECF after acidification of lymphocytes and platelets with sodium propionate at five (10-50mM) doses. Na+/H+ exchange was accelerated in this patient compared to normal controls. NaHCO3 treatment significantly decreased Na+/H+ exchange in lymphocytes, but not in platelets. These findings suggest that Na+/H+ exchange can be influenced by NaHCO3 ingestion at doses that only modestly affect systemic pH. Since Na+/H+ exchange is involved in stimulus response coupling, cell growth regulation, cell differentiation, and perhaps the progression of nephrosclerosis, these observations may have clinical relevanc

Monitoring and Pay: An Experiment on Employee Performance under Endogenous Supervision

We present an experimental test of a shirking model where monitoring intensity is endogenous and effort a continuous variable. Wage level, monitoring intensity and consequently the desired enforceable effort level are jointly determined by the maximization problem of the firm. As a result, monitoring and pay should be complements. In our experiment, between and within treatment variation is qualitatively in line with the normative predictions of the model under standard assumptions. Yet, we also find evidence for reciprocal behavior. Our data analysis shows, however, that it does not pay for the employer to solely rely on the reciprocity of employees