804 research outputs found

    Trade Policy with Heterogeneous Traders: Do Quotas Get a Bum Rap?

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    This paper considers the effects of trade policy--tariffs and quotas--when importing is done by competitive traders who are identical ex ante but differ ex post. We show that the standard equivalence results no longer hold and the conventional ranking of tariffs and quotas is turned on its head: quotas are not as bad for welfare as previously believed, while tariffs may restrict trade by more than originally intended. Furthermore, the allocation of property rights (quota licenses) has real effects beyond the distribution of rents; this, in turn, has implications for the effects of corruption on welfare.

    Mechanics and force transmission in soft composites of rods in elastic gels

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    We report detailed theoretical investigations of the micro-mechanics and bulk elastic properties of composites consisting of randomly distributed stiff fibers embedded in an elastic matrix in two and three dimensions. Recent experiments published in Physical Review Letters [102, 188303 (2009)] have suggested that the inclusion of stiff microtubules in a softer, nearly incompressible biopolymer matrix can lead to emergent compressibility. This can be understood in terms of the enhancement of the compressibility of the composite relative to its shear compliance as a result of the addition of stiff rod-like inclusions. We show that the Poisson's ratio ν\nu of such a composite evolves with increasing rod density towards a particular value, or {\em fixed point}, independent of the material properties of the matrix, so long as it has a finite initial compressibility. This fixed point is ν=1/4\nu=1/4 in three dimensions and ν=1/3\nu=1/3 in two dimensions. Our results suggest an important role for stiff filaments such as microtubules and stress fibers in cell mechanics. At the same time, our work has a wider elasticity context, with potential applications to composite elastic media with a wide separation of scales in stiffness of its constituents such as carbon nanotube-polymer composites, which have been shown to have highly tunable mechanics.Comment: 10 pages, 8 figure

    Functional Feeding Groups of Aquatic Macroinvertebrates on Natural and Artificial Leaves in Forested Stream Habitats in the Sebago Lake Land Reserve

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    We investigated preferential insect colonization of natural versus artificial leaves in forested streams to determine the impact of invertebrate-substrate associations on macroinvertebrate community composition and ecosystem nutrient cycling. We created 10 onion bags filled with natural maple leaves and 10 filled with artificial maple leaves, and placed 5 of each in two forested streams, one larger and one smaller, in the Sebago Lake Land Reserve in Standish, Maine. We identified the aquatic macroinvertebrates found on these samples after approximately one month to order-level and used Maine DEP biomonitoring data and functional feeding group taxonomies to classify macroinvertebrates by functional feeding groups. There was a greater difference in Simpson diversity values between habitats than between substrate types and a substantially greater difference in functional feeding group composition between habitats than between substrate types. The patterns in functional feeding group abundance across habitats (specifically the decline in shredder proportions from the smaller stream to the larger stream) match the patterns of the river continuum concept. This indicates an unexpectedly high degree of small-scale ecosystem heterogeneity, with wide potential implications for ecosystem-level macroinvertebrate community structure and nutrient cycling

    Min-O-Mee: A Proximity Based Network Application Leveraging The AllJoyn Framework

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    Close proximity of mobile devices can be utilized to create ad hoc and dynamic networks. These mobile Proximity Based Networks (PBNs) are Opportunistic Networks that enable devices to identify and communicate with each other without relying on any communication infrastructure. In addition, these networks are self organizing, highly dynamic and facilitate effective real-time communication. These characteristics render them very useful in a wide variety of complex scenarios such as vehicular communication, e-health, disaster networks, mobile social networks etc. In this work we employ the AllJoyn framework from Qualcomm which facilitates smooth discovery, attachment and data sharing between devices in close proximity. We develop Min-O-Mee, a Minutes-of-Meeting app prototype in the Android platform, utilizing the AllJoyn framework. Min-O-Mee allows one of the participants to create a minutes-of-meeting document which can be shared with and edited by the other participants in the meeting. The app harnesses the spatial proximity of participants in a meeting and enables seamless data exchange between them. This characteristic allows Min-O-Mee to share not just minutes-of-meeting, but any data that needs to be exchanged among the participants, making it a versatile app. Further, we extend the basic AllJoyn framework to enable multi-hop communication among the devices in the PBN. We devise a novel routing mechanism that is suited to a proximity centric wireless network as it facilitates data routing and delivery over several hops to devices that are at the fringe of the PBN

    HPV-Reactive T-Cell Receptor Expand in Combination Therapy

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    https://openworks.mdanderson.org/sumexp22/1001/thumbnail.jp

    Preventing Homelessness and Promoting Housing Stability: A Comparative Analysis

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    This final evaluation report is the culmination of a three-year investment of time, energy and resources involving 28 Massachusetts nonprofit organizations: 7 foundations, led by the Boston Foundation, The Massachusetts Department of Housing and Community Development; and Homes for Families which joined with the Center for Social Policy team to conduct 10 focus groups involving 72 parents and individuals who shared their perspectives on homelessness prevention, with the guidance of a consumer advisory board involving six persons who have experienced homelessness. Collectively, we engaged in this evaluation effort because we believed that the outcomes of interventions, practice experience of service providers, and the lived experiences of the families and individuals they served have meaning for improving service practices, changing public policies, and increasing public and private resources to prevent other Massachusetts households from falling into homelessness

    Leptospira interrogans outer membrane protein-based nanohybrid sensor for the diagnosis of leptospirosis

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    Leptospirosis is an underestimated tropical disease caused by the pathogenic Leptospira species and responsible for several serious health problems. Here, we aimed to develop an ultrasen-sitive DNA biosensor for the rapid and on-site detection of the Loa22 gene of Leptospira interrogans using a gold nanoparticle–carbon nanofiber composite (AuN/CNF)-based screen-printed electrode. Cyclic voltammetry and electrochemical impedance were performed for electrochemical analysis. The sensitivity of the sensor was 5431.74 µA/cm2 /ng with a LOD (detection limit) of 0.0077 ng/µL using cyclic voltammetry. The developed DNA biosensor was found highly specific to the Loa22 gene of L. interrogans, with a storage stability at 4¿ C for 180 days and a 6% loss of the initial response. This DNA-based sensor only takes 30 min for rapid detection of the pathogen, with a higher specificity and sensitivity. The promising results obtained suggest the application of the developed sensor as a point of care device for the diagnosis of leptospirosis.This research was funded by the Indian Council of Medical Research (ICMR), grant Leptos/27/2013-ECD-1. N.C.-M. acknowledges the Portuguese Foundation for Science and Technology under the Horizon 2020 Program (PTDC/PSI-GER/28076/2017), Supported by Excellence project FIM UHK (K.K.)

    Duration of acute kidney injury in critically ill patients

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    BACKGROUND:Duration of acute kidney injury (AKI) has been recognized a risk factor for adverse outcomes following AKI. We sought to examine the relationship of AKI duration and recurrent AKI with short-term outcomes in critically ill patients who were mechanically ventilated and met criteria for the acute respiratory distress syndrome. METHODS:Participants in the NHLBI ARDS Network SAILS multicenter trial who developed AKI were included in this analysis and divided into groups based on AKI duration. Differences in outcomes were evaluated using t test and Chi-square test. Competing risks regression and Cox regression were used to evaluate factors associated with resolving AKI and recurrent AKI. RESULTS:In total, 238 patients were included in the study. Seventy-seven patients had short duration AKI (1-2 days), 47 medium duration AKI (3-7 days), 87 persistent AKI (> 7 days) and 38 died during their AKI episode. Persistent AKI was associated with worse outcomes including increased ICU length of stay, time on the ventilator and days with cardiovascular failure. We found no clinical differences between patients with short and medium duration AKI, even when accounting for AKI severity and recurrent AKI. Patients with resolving AKI were less likely to have oliguria or moderate/severe ARDS on the day AKI criteria were met. Recurrent AKI was associated with poorer clinical outcomes. No baseline clinical factors were found to predict development of recurrent AKI. CONCLUSIONS:In critically ill patients with sepsis-associated ARDS and AKI, the impact of short and medium duration AKI on clinical outcomes was modest. Persistent and recurrent AKI were both associated with worse clinical outcomes, emphasizing the importance of identifying these patients, who may benefit from novel interventions

    Atmospheric multiple scattering of fluorescence and Cherenkov light emitted by extensive air showers

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    Atmospheric scattering of light emitted by an air shower not only attenuates direct fluorescence light from the shower, but also contributes to the observed shower light. So far only direct and singly-scattered Cherenkov photons have been taken into account in routine analyses of the observed optical image of air showers. In this paper a Monte Carlo method of evaluating the contribution of multiply scattered light to the optical air shower image is presented, as well as results of simulations and a parameterization of scattered light contribution to measured shower signal.Comment: 27 pages, 18 figures, accepted for publication in NIM

    Design and Characterization of Buccoadhesive Liquisolid System of an Antihypertensive Drug

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    Nifedipine is an antihypertensive BCS class II drug which has poor bioavailability when given orally. The objective of the present study was to increase the bioavailability of nifedipine, by formulation and evaluation of a buccoadhesive liquisolid system using magnesium aluminium silicate (Neusilin) as both carrier and coating material and dissolution media were selected based on the solubility studies. A mixture of carboxymethylcellulose sodium and carbomer was used as mucoadhesive polymers. Buccoadhesive tablets were prepared by direct compression. FTIR studies confirmed no interaction between drug and excipients. XRD studies indicated change/reduction in crystallinity of drug. The powder characteristics were evaluated by different flow parameters to comply with pharmacopoeial specifications. The dissolution studies for liquisolid compacts and tablet formulations were carried out and it was found that nifedipine liquisolid tablets formulated from bioadhesive polymers containing 49% liquisolid system, 17.5% carbomer, and 7.5% carboxymethylcellulose sodium showed the best results in terms of dissolution properties. Prepared formulation batches were evaluated for swelling, bioadhesion strength, ex vivo residence time, and permeability studies. The optimized batch was showing promising features of the system. Formulating nifedipine as a buccoadhesive tablet allows reduction in dose and offers better control over the plasma levels
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