Vorticity cutoff in nonlinear photonic crystals

Using group theory arguments, we demonstrate that, unlike in homogeneous media, no symmetric vortices of arbitrary order can be generated in two-dimensional (2D) nonlinear systems possessing a discrete-point symmetry. The only condition needed is that the non-linearity term exclusively depends on the modulus of the field. In the particular case of 2D periodic systems, such as nonlinear photonic crystals or Bose-Einstein condensates in periodic potentials, it is shown that the realization of discrete symmetry forbids the existence of symmetric vortex solutions with vorticity higher than two.Comment: 4 pages, 5 figures; minor changes in address and reference

Evaluación preliminar de condensadores de rocío y su utilización para riego de plántulas de árboles en Puerto Rico

Dew condensers have been proposed as a means to reduce drought mortality of tree seedlings in early stages of reforestation projects. We investigated the amount of dew condensate produced by locally constructed dew condensers, constructed with three different infrared emitting surfaces: standard polyethylene/ TiO2 / BaSO4 foil, thermoplastic polyolefin (TPO), and plastic coated with locally available Lanco UrethanizerTM8 roofing paint. All surfaces produced similar amounts of total dew condensate, typically ranging between 0.05 and 0.25 L/m2/night. However, the materials differed in the fraction of dew running off the surfaces, which represents the water available for tree seedlings. Highest runoff fractions were obtained with painted surfaces, followed by polyethylene and polyolefin surfaces, respectively. Considerably greater amounts of nightly dew condensate were observed during the winter than in summer, attributed to differences in night length and cloud cover. A commercially available dew condenser, the Groasis WaterboxxTM, did not generate more than 0.04 L per night of runoff dew, due primarily to a small condenser surface area of < 0.2 m2. A field study showed that 1 m2 dew condensers maintained the root zone of mahogany seedlings at matric potentials > -60 kPa during dry spells. Overall, results indicated that passive dew condensers with condenser areas of 1 m2 are capable of producing sufficient water for survival of small tree seedlings during drought periods.Los condensadores de rocío se han propuesto como mecanismo para proveer agua a plántulas de árboles en etapas iniciales de reforestación. Se investigó el potencial de condensadores de fabricación local para producir agua. Se compararon condensadores construidos con tres diferentes superficies emisoras en infrarrojo: lámina estándar de polietileno impregnado con TiO2 y BaSO4, poli-olefina termoplástica (TPO), y plástico recubierto con pintura Lanco UrethanizerTM disponible en ferreterías locales. Todas las superficies produjeron cantidades similares de condensado total de rocío, por lo general entre 0.05 y 0.25 L /m2/noche. Sin embargo, los materiales variaron en la fracción del condensado escurrido desde las superficies, lo cual representa el agua disponible para las plántulas. Las fracciones de escorrentía más altas se obtuvieron con las superficies pintadas, seguido por las superficies de polietileno y de poli-olefina, respectivamente. Las cantidades de condensado durante el invierno fueron mayores que en verano, probablemente debido a noches más largas y menor nubosidad en invierno. Se evaluó el volumen de rocío (escorrentía) producido por un modelo comercial de condensador de rocío, el Groasis WaterboxxTM. Este nunca superó 0.04 L por noche, atribuido principalmente a la pequeña área de superficie (< 0.2 m2) del condensador. Un experimento de campo mostró que condensadores de rocío de 1 m2 mantuvieron el potencial matricial de agua en la zona de raíces de plántulas de caoba en valores > -60 kPa durante periodos de sequía. En general, los resultados indicaron que los condensadores de rocío con áreas superficiales de 1 m2 producen suficiente agua para la supervivencia de pequeñas plántulas de árboles

Aircraft Conceptual Design Using Vehicle Sketch Pad

Vehicle Sketch Pad (VSP) is a parametric geometry modeling tool that is intended for use in the conceptual design of aircraft. The intent of this software is to rapidly model aircraft configurations without expending the expertise and time that is typically required for modeling with traditional Computer Aided Design (CAD) packages. VSP accomplishes this by using parametrically defined components, such as a wing that is defined by span, area, sweep, taper ratio, thickness to cord, and so on. During this phase of frequent design builds, changes to the model can be rapidly visualized along with the internal volumetric layout. Using this geometry-based approach, parameters such as wetted areas and cord lengths can be easily extracted for rapid external performance analyses, such as a parasite drag buildup. At the completion of the conceptual design phase, VSP can export its geometry to higher fidelity tools. This geometry tool was developed by NASA and is freely available to U.S. companies and universities. It has become integral to conceptual design in the Aeronautics Systems Analysis Branch (ASAB) here at NASA Langley Research Center and is currently being used at over 100 universities, aerospace companies, and other government agencies. This paper focuses on the use of VSP in recent NASA conceptual design studies to facilitate geometry-centered design methodology. Such a process is shown to promote greater levels of creativity, more rapid assessment of critical design issues, and improved ability to quickly interact with higher order analyses. A number of VSP vehicle model examples are compared to CAD-based conceptual design, from a designer perspective; comparisons are also made of the time and expertise required to build the geometry representations as well

Maximum Power of Thermally and Electrically Coupled Thermoelectric Generators

In a recent work, we have reported a study on the figure of merit of a thermoelectric system composed by thermoelectric generators connected electrically and thermally in different configurations. In this work, we are interested in analyzing the output power delivered by a thermoelectric system for different arrays of thermoelectric materials in each configuration. Our study shows the impact of the array of thermoelectric materials in the output power of the composite system. We evaluate numerically the corresponding maximum output power for each configuration and determine the optimum array and configuration for maximum power. We compare our results with other recently reported studies

On-sky wide field adaptive optics correction using multiple laser guide stars at the MMT

We describe results from the first astronomical adaptive optics system to use multiple laser guide stars, located at the 6.5-m MMT telescope in Arizona. Its initial operational mode, ground-layer adaptive optics (GLAO), provides uniform stellar wavefront correction within the 2 arc minute diameter laser beacon constellation, reducing the stellar image widths by as much as 53%, from 0.70 to 0.33 arc seconds at lambda = 2.14 microns. GLAO is achieved by applying a correction to the telescope's adaptive secondary mirror that is an average of wavefront measurements from five laser beacons supplemented with image motion from a faint stellar source. Optimization of the adaptive optics system in subsequent commissioning runs will further improve correction performance where it is predicted to deliver 0.1 to 0.2 arc second resolution in the near-infrared during a majority of seeing conditions.Comment: 13 pages, 1 table, 7 figures. Accepted for publication in Astrophysical Journal. Expected March 200

Medication therapy management delivery by community pharmacists: Insights from a national sample of Medicare Part D beneficiaries

IntroductionThe Medicare Part D medication therapy management (MTM) program positions pharmacists to optimize beneficiaries’ medications and improve care. Little is known regarding Part D MTM delivery by community pharmacists and other pharmacist provider types.ObjectivesTo (a) characterize Medicare Part D MTM delivery by community pharmacists, (b) compare MTM delivery by community pharmacists to other pharmacists, and (c) generate hypotheses for future research.MethodsA descriptive cross‐sectional study using merged data from a 20% random sample of Medicare beneficiary enrollment data with a 100% sample of recently available 2014 Part D MTM files was conducted. Andersen’s Behavioral Model was applied to describe MTM delivery across beneficiary characteristics. Descriptive and bivariate statistics were used to compare delivery of MTM between community and other pharmacist providers.ResultsAmong beneficiaries sampled, community pharmacists provided comprehensive medication reviews (CMRs) to 22% (n = 26 337) of beneficiaries receiving at least one CMR. Almost half (49.4%) were provided face‐to‐face. Across pharmacist cohorts, median days to CMR offer of post‐MTM program enrollment were within the 60‐day policy requirement. The community pharmacist cohort had fewer days from CMR offer to receipt (median 47 days). Community pharmacists provided more medication therapy problem (MTP) recommendations (mean [SD] of 1.8 [3.5]; P < .001), but resolved less MTPs (0.2 [0.7]; P < .001), and most commonly served beneficiaries that were in the south but less in the west/northeast. Additionally, community pharmacists served a smaller proportion of black beneficiaries, yet a larger proportion of Hispanic beneficiaries (P < .001).ConclusionCommunity pharmacists provided approximately one in five CMRs for MTM eligible beneficiaries in 2014, with CMRs occurring more quickly, resulting in more MTP recommendations, but resolving less MTPs than those provided by noncommunity pharmacists. Future research should explore geographic/racial‐ethnic disparities in beneficiaries served and strategies to increase negligible MTP resolution by community pharmacists.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151286/1/jac51160.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151286/2/jac51160_am.pd

CP violation and limits on New Physics including recent BsB_s measurements

We analyse present constraints on the SM parameter space and derive, in a model independent way, various bounds on New Physics contributions to $B_d^0$--$\bar B_d^0$ and $B_s^0$--$\bar B_s^0$ mixings. Our analyses include information on a large set of asymmetries, leading to the measurement of the CKM phases $\gamma$ and $\bar\beta$, as well as recent data from D0 and CDF related to the $B_s^0$--$\bar B_s^0$ system such as the measurement of $\Delta M_{B_s}$, $A_{SL}$ and $\Delta\Gamma_{s}^{CP}$. We examine in detail several observables such as the asymmetries $A_{sl}^d$, $A_{SL}$, the width differences $\Delta\Gamma_{d}$ and $\Delta\Gamma_{s}^{CP}$ and discuss the r\^ole they play in establishing the limits on New Physics. The present data clearly favour the SM, with the New Physics favoured region placed around the SM solution. A New Physics solution significantly different from the SM is still allowed, albeit quite disfavoured (2.6% probability). We analyse the presently available indirect knowledge on the phase $\bar\chi$ entering in $B_s^0$--$\bar B_s^0$ mixing and study the impact of a future measurement of $\bar\chi$ to be achieved at LHC, through the measurement of the time-dependent CP asymmetry in $B_s\to J/\Psi \Phi$ decays.Comment: 29 pages, 31 figures; updated analyses and reference

Efficacy of transoral fundoplication vs omeprazole for treatment of regurgitation in a randomized controlled trial.

Background The aim of this randomized, crossover study was to determine if transoral fundoplication (TF) could further improve clinical outcomes in partial responders to high-dose (HD) proton-pump inhibitor (PPI) therapy and to evaluate durability of TF. Methods In seven United States centers, patients with hiatal hernia ≤2 cm and abnormal esophageal acid exposure (EAE) were randomized to TF (n = 40) or HD PPIs (n = 23) group. At 6-month follow-up, PPI patients underwent crossover. We assessed clinical outcomes 6-month post TF in crossover patients (COP), as compared to 6-month of HD PPI therapy, and 12-month outcomes in patients initially randomized to TF. The primary outcome was symptom control evaluated by Reflux Disease Questionnaire and Reflux Symptom Index. Secondary outcomes included healing of esophagitis, normalization of EAE and PPI use after TF. We analyzed 21 COP and 39 TF patients. McNemar’s test or Fisher exact test was used to compare proportions. Results Of 63 randomized patients, 3 were lost to follow-up, leaving 39 TF and 21 COP for analyses. In the COP, TF further improved control of regurgitation and of atypical symptoms achieved after six months of HD PPIs. Of 20 patients with GERD symptoms after six months of high-dose PPI therapy, 65% (13/20) reported global elimination of troublesome regurgitation and atypical symptoms post TF off PPIs; 67% (6/9) reported no troublesome regurgitation. Esophagitis further healed in 75% (6/8) of patients. Seventy-one percent of COP patients were off PPIs six months following TF. Normalization of EAE decreased from 52% after HD PPIs (on PPIs) to 33% after TF (off PPIs), p =0.388. In the original TF group, 12-month post TF, 77% of patients achieved complete symptom control, 82% ceased PPI therapy, 100% healed esophagitis and 45% normalized EAE. Conclusions The results of this study indicate that in patients with incomplete symptom control on high-dose PPI therapy TF may provide further elimination of symptoms and esophagitis healing. In the original TF group, the clinical outcomes of TF remained stable between 6- and 12-month follow-up. Trial registration Clinicaltrials.gov: NCT01647958

Entropically-driven binding of mithramycin in the minor groove of C/G-rich DNA sequences

The antitumour antibiotic mithramycin A (MTA) is a DNA minor-groove binding ligand. It binds to C/G-rich tracts as a dimer that forms in the presence of divalent cations such as Mg2+. Differential scanning calorimetry, UV thermal denaturation, isothermal titration calorimetry and competition dialysis were used, together with computations of the hydrophobic free energy of binding, to determine the thermodynamic profile of MTA binding to DNA. The results were compared to those obtained in parallel using the structurally related mithramycin SK (MSK). The binding of MTA to salmon testes DNA determined by UV melting studies (Kobs = 1.2 (±0.3) × 105 M−1) is tighter than that of MSK (2.9 (±1.0) × 104 M−1) at 25°C. Competition dialysis studies showed a tighter MTA binding to both salmon testes DNA (42% C + G) and Micrococcus lysodeikticus DNA (72% C + G). The thermodynamic analysis of binding data at 25°C shows that the binding of MTA and MSK to DNA is entropically driven, dominated by the hydrophobic transfer of the antibiotics from solution to the DNA-binding site. Direct molecular recognition between MTA or MSK and DNA through hydrogen bonding and van der Waals contacts may also contribute significantly to complex formation