Mostrando recursos 1 - 20 de 6.787

  1. Equity in the Receipt of Oseltamivir in the United States During the H1N1 Pandemic

    Franklin, Jessica Myers; Choudhry, Niteesh Kumar; Uscher-Pines, Lori; Brill, Gregory; Matlin, Olga S.; Fischer, Michael Adam; Schneeweiss, Sebastian; Avorn, Jerry Lewis; Brennan, Troyen Anthony; Shrank, William
    Objectives. We assessed the relationship between individual characteristics and receipt of oseltamivir (Tamiflu) in the United States during the H1N1 pandemic and other flu seasons. Methods. In a cohort of individuals enrolled in pharmacy benefit plans, we used a multivariate logistic regression model to measure associations between subscriber characteristics and filling a prescription for oseltamivir during 3 flu seasons (October 2006–May 2007, October 2007–May 2008, and October 2008–May 2010). In 19 states with county-level influenza rates reported, we controlled for disease burden. Results. Approximately 56 million subscribers throughout the United States were included in 1 or more study periods. During pandemic flu,...

  2. Dropwise condensation on hydrophobic bumps and dimples

    Yao, Yuehan; Aizenberg, Joanna; Park, Kyoo-Chul
    Engineering and Applied Sciences

  3. Camflow: Managed Data-Sharing for Cloud Services

    Pasquier, Thomas; Singh, Jatinder; Eyers, David; Bacon, Jean
    A model of cloud services is emerging whereby a few trusted providers manage the underlying hardware and communications whereas many companies build on this infrastructure to offer higher level, cloud-hosted PaaS services and/or SaaS applications. From the start, strong isolation between cloud tenants was seen to be of paramount importance, provided first by virtual machines (VM) and later by containers, which share the operating system (OS) kernel. Increasingly it is the case that applications also require facilities to effect isolation and protection of data managed by those applications. They also require flexible data sharing with other applications, often across the...

  4. Clouds of Things Need Information Flow Control with Hardware Roots of Trust

    Pasquier, Thomas; Singh, Jatinder; Bacon, Jean
    There is a clear, outstanding need for new security mechanisms that allow data to be managed and controlled within the cloud-enabled Internet of Things. Towards this, we propose an approach based on Information Flow Control (IFC) that allows: (1) the continuous, end-to-end enforcement of data flow policy, and (2) the generation of provenance-like audit logs to demon- strate policy adherence and contractual/regulatory compliance. Further, we discuss the role of Trusted Platform Modules (TPMs) in supporting such a system, by providing hardware roots of trust. TPMs can be leveraged to validate software configurations, including the IFC enforcement mechanism, both in the...

  5. Genotypic variability enhances the reproducibility of an ecological study

    Milcu, Alexandru; Puga-Freitas, Ruben; Ellison, Aaron M.; Blouin, Manuel; Scheu, Stefan; Freschet, Grégoire T.; Rose, Laura; Barot, Sebastien; Cesarz, Simone; Eisenhauer, Nico; Girin, Thomas; Assandri, Davide; Bonkowski, Michael; Buchmann, Nina; Butenschoen, Olaf; Devidal, Sebastien; Gleixner, Gerd; Gessler, Arthur; Gigon, Agnès; Greiner, Anna; Grignani, Carlo; Hansart, Amandine; Kayler, Zachary; Lange, Markus; Lata, Jean-Christophe; Le Galliard, Jean-François; Lukac, Martin; Mannerheim, Neringa; Müller, Marina E. H.; Pando, Anne; Rotter, Paula; Scherer-Lorenzen, Michael; Seyhun, Rahme; Urban-Mead, Katherine; Weigelt, Alexandra; Zavattaro, Laura; Roy, Jacques
    Many scientific disciplines are currently experiencing a “reproducibility crisis” because numerous scientific findings cannot be repeated consistently. A novel but controversial hypothesis postulates that stringent levels of environmental and biotic standardization in experimental studies reduces reproducibility by amplifying impacts of lab-specific environmental factors not accounted for in study designs. A corollary to this hypothesis is that a deliberate introduction of controlled systematic variability (CSV) in experimental designs may lead to increased reproducibility. To test this hypothesis, we had 14 European laboratories run a simple microcosm experiment using grass (Brachypodium distachyon L.) monocultures and grass and legume (Medicago truncatula Gaertn.) mixtures....

  6. Flow Batteries: Alkaline Benzoquinone Aqueous Flow Battery for Large-Scale Storage of Electrical Energy

    Yang, Zhengjin; Tong, Liuchuan; Tabor, Daniel; Beh, Eugene S.; Goulet, Marc-Antoni; De Porcellinis, Diana; Aspuru-Guzik, Alan; Gordon, Roy Gerald; Aziz, Michael J.
    We introduce an aqueous flow battery based on low-cost, non-flammable, non-corrosive and Earth-abundant elements. During charging, electrons are stored in a concentrated water solution of 2,5-dihydroxy-1,4-benzoquinone (DHBQ), which rapidly receives electrons with inexpensive carbon electrodes without the assistance of any metal electro-catalyst. Electrons are withdrawn from a second water solution of a food additive, potassium ferrocyanide (K4Fe(CN)6). When these two solutions flow along opposite sides of a cation-conducting membrane, this flow battery delivers a cell potential of 1.21 V, a peak galvanic power density of 300 mW/cm2 and a coulombic efficiency exceeding 99%. Continuous cell cycling at 100 mA/cm2 shows...

  7. Multiplexed imaging of high-density libraries of RNAs with MERFISH and expansion microscopy

    Wang, Guiping; Moffitt, Jeffrey R.; Zhuang, Xiaowei
    As an image-based single-cell transcriptomics approach, multiplexed error-robust fluorescence in situ hybridization (MERFISH) allows hundreds to thousands of RNA species to be identified, counted and localized in individual cells while preserving the native spatial context of RNAs. In MERFISH, RNAs are identified via a combinatorial labeling approach that encodes RNA species with error-robust barcodes followed by sequential rounds of single-molecule FISH (smFISH) to read out these barcodes. The accuracy of RNA identification relies on spatially separated signals from individual RNA molecules, which limits the density of RNAs that can be measured and makes the multiplexed imaging of a large number...

  8. Relatively slow stochastic gene-state switching in the presence of positive feedback significantly broadens the region of bimodality through stabilizing the uninduced phenotypic state

    Ge, Hao; Wu, Pingping; Qian, Hong; Xie, Xiaoliang Sunney
    Within an isogenic population, even in the same extracellular environment, individual cells can exhibit various phenotypic states. The exact role of stochastic gene-state switching regulating the transition among these phenotypic states in a single cell is not fully understood, especially in the presence of positive feedback. Recent high-precision single-cell measurements showed that, at least in bacteria, switching in gene states is slow relative to the typical rates of active transcription and translation. Hence using the lac operon as an archetype, in such a region of operon-state switching, we present a fluctuating-rate model for this classical gene regulation module, incorporating the...

  9. The Cannabinoid Content of Legal Cannabis in Washington State Varies Systematically Across Testing Facilities and Popular Consumer Products

    Jikomes, Nick; Zoorob, Michael
    The majority of adults in the U.S. now have state-legal access to medical or recreational cannabis products, despite their federal prohibition. Given the wide array of pharmacologically active compounds in these products, it is essential that their biochemical profile is measured and reported to consumers, which requires accurate laboratory testing. However, no universal standards for laboratory testing protocols currently exist, and there is controversy as to whether all reported results are legitimate. To investigate these concerns, we analyzed a publicly available seed-to-sale traceability dataset from Washington state containing measurements of the cannabinoid content of legal cannabis products from state-certified laboratories....

  10. Electrospinning over Solvent Casting: Tuning of Mechanical Properties of Membranes

    Ghosal, Kajal; Chandra, Aniruddha; G., Praveen; S., Snigdha; Roy, Sudeep; Agatemor, Christian; Thomas, Sabu; Provaznik, Ivo
    We put forth our opinion regarding the enhanced plasticity and modulation of mechanical properties of polymeric films obtained through electrospinning process in this article. In majority of the pharmaceutical, biomedical, and packaging applications, it is desirable that polymer based matrices should be soft, flexible, and have a moderate toughness. In order to convert inflexible and brittle polymers, adjuvants in the form of plasticizers are added to improve the flexibility and smoothness of solvent casted polymer films. However, many of these plasticizers are under scrutiny for their toxic effects and environmental hazards. In addition, plasticizers also increase the cost of end...

  11. Disentangling Immediate Adaptive Introgression from Selection on Standing Introgressed Variation in Humans

    Jagoda, Evelyn; Lawson, Daniel J; Wall, Jeffrey D; Lambert, David; Muller, Craig; Westaway, Michael; Leavesley, Matthew; Capellini, Terence D; Mirazón Lahr, Marta; Gerbault, Pascale; Thomas, Mark G; Migliano, Andrea Bamberg; Willerslev, Eske; Metspalu, Mait; Pagani, Luca
    Abstract Recent studies have reported evidence suggesting that portions of contemporary human genomes introgressed from archaic hominin populations went to high frequencies due to positive selection. However, no study to date has specifically addressed the postintrogression population dynamics of these putative cases of adaptive introgression. Here, for the first time, we specifically define cases of immediate adaptive introgression (iAI) in which archaic haplotypes rose to high frequencies in humans as a result of a selective sweep that occurred shortly after the introgression event. We define these cases as distinct from instances of selection on standing introgressed variation (SI), in which...

  12. The viscosity of atmospherically relevant organic particles

    Reid, Jonathan P.; Bertram, Allan K.; Topping, David O.; Laskin, Alexander; Martin, Scot T.; Petters, Markus D.; Pope, Francis D.; Rovelli, Grazia
    The importance of organic aerosol particles in the environment has been long established, influencing cloud formation and lifetime, absorbing and scattering sunlight, affecting atmospheric composition and impacting on human health. Conventionally, ambient organic particles were considered to exist as liquids. Recent observations in field measurements and studies in the laboratory suggest that they may instead exist as highly viscous semi-solids or amorphous glassy solids under certain conditions, with important implications for atmospheric chemistry, climate and air quality. This review explores our understanding of aerosol particle phase, particularly as identified by measurements of the viscosity of organic particles, and the atmospheric...

  13. Herbivorous turtle ants obtain essential nutrients from a conserved nitrogen-recycling gut microbiome

    Hu, Yi; Sanders, Jon G.; Łukasik, Piotr; D’Amelio, Catherine L.; Millar, John S.; Vann, David R.; Lan, Yemin; Newton, Justin A.; Schotanus, Mark; Kronauer, Daniel J. C.; Pierce, Naomi E.; Moreau, Corrie S.; Wertz, John T.; Engel, Philipp; Russell, Jacob A.
    Nitrogen acquisition is a major challenge for herbivorous animals, and the repeated origins of herbivory across the ants have raised expectations that nutritional symbionts have shaped their diversification. Direct evidence for N provisioning by internally housed symbionts is rare in animals; among the ants, it has been documented for just one lineage. In this study we dissect functional contributions by bacteria from a conserved, multi-partite gut symbiosis in herbivorous Cephalotes ants through in vivo experiments, metagenomics, and in vitro assays. Gut bacteria recycle urea, and likely uric acid, using recycled N to synthesize essential amino acids that are acquired by...

  14. Signatures of human impact on self-organized vegetation in the Horn of Africa

    Gowda, Karna; Iams, Sarah; Silber, Mary
    In many dryland environments, vegetation self-organizes into bands that can be clearly identified in remotely-sensed imagery. The status of individual bands can be tracked over time, allowing for a detailed remote analysis of how human populations affect the vital balance of dryland ecosystems. In this study, we characterize vegetation change in areas of the Horn of Africa where imagery taken in the early 1950s is available. We find that substantial change is associated with steep increases in human activity, which we infer primarily through the extent of road and dirt track development. A seemingly paradoxical signature of human impact appears...

  15. Chemical evidence of inter-hemispheric air mass intrusion into the Northern Hemisphere mid-latitudes

    Li, S.; Park, S.; Lee, J.-Y.; Ha, K.-J.; Park, M.-K.; Jo, C. O.; Oh, H.; Mühle, J.; Kim, K.-R.; Montzka, S. A.; O’Doherty, S.; Krummel, P. B.; Atlas, E.; Miller, B. R.; Moore, F.; Weiss, R. F.; Wofsy, S. C.
    The East Asian Summer Monsoon driven by temperature and moisture gradients between the Asian continent and the Pacific Ocean, leads to approximately 50% of the annual rainfall in the region across 20–40°N. Due to its increasing scientific and social importance, there have been several previous studies on identification of moisture sources for summer monsoon rainfall over East Asia mainly using Lagrangian or Eulerian atmospheric water vapor models. The major source regions for EASM previously proposed include the North Indian Ocean, South China Sea and North western Pacific. Based on high-precision and high-frequency 6-year measurement records of hydrofluorocarbons (HFCs), here we...

  16. Evolutionary persistence in Gunnera and the contribution of southern plant groups to the tropical Andes biodiversity hotspot

    Bacon, Christine D.; Velásquez-Puentes, Francisco J.; Hinojosa, Luis Felipe; Schwartz, Thomas; Oxelman, Bengt; Pfeil, Bernard; Arroyo, Mary T.K.; Wanntorp, Livia; Antonelli, Alexandre
    Several studies have demonstrated the contribution of northern immigrants to the flora of the tropical Andes—the world’s richest and most diverse biodiversity hotspot. However, much less is known about the biogeographic history and diversification of Andean groups with southern origins, although it has been suggested that northern and southern groups have contributed roughly equally to the high Andean (i.e., páramo) flora. Here we infer the evolutionary history of the southern hemisphere plant genus Gunnera, a lineage with a rich fossil history and an important ecological role as an early colonising species characteristic of wet, montane environments. Our results show striking...

  17. Transition by head-on collision: mechanically mediated manoeuvres in cockroaches and small robots

    Jayaram, Kaushik; Mongeau, Jean-Michel; Mohapatra, Anand; Birkmeyer, Paul; Fearing, Ronald S.; Full, Robert J.
    Exceptional performance is often considered to be elegant and free of ‘errors’ or missteps. During the most extreme escape behaviours, neural control can approach or exceed its operating limits in response time and bandwidth. Here we show that small, rapid running cockroaches with robust exoskeletons select head-on collisions with obstacles to maintain the fastest escape speeds possible to transition up a vertical wall. Instead of avoidance, animals use their passive body shape and compliance to negotiate challenging environments. Cockroaches running at over 1 m or 50 body lengths per second transition from the floor to a vertical wall within 75...

  18. Middle and Later Stone Age chronology of Kisese II rockshelter (UNESCO World Heritage Kondoa Rock-Art Sites), Tanzania

    Tryon, Christian A.; Lewis, Jason E.; Ranhorn, Kathryn L.; Kwekason, Amandus; Alex, Bridget; Laird, Myra F.; Marean, Curtis W.; Niespolo, Elizabeth; Nivens, Joelle; Mabulla, Audax Z. P.
    The archaeology of East Africa during the last ~65,000 years plays a central role in debates about the origins and dispersal of modern humans, Homo sapiens. Despite the historical importance of the region to these discussions, reliable chronologies for the nature, tempo, and timing of human behavioral changes seen among Middle Stone Age (MSA) and Later Stone Age (LSA) archaeological assemblages are sparse. The Kisese II rockshelter in the Kondoa region of Tanzania, originally excavated in 1956, preserves a ≥ 6-m-thick archaeological succession that spans the MSA/LSA transition, with lithic artifacts such as Levallois and bladelet cores and backed microliths,...

  19. Flexibility in motor timing constrains the topology and dynamics of pattern generator circuits

    Pehlevan, Cengiz; Ali, Farhan; Ölveczky, Bence P.
    Temporally precise movement patterns underlie many motor skills and innate actions, yet the flexibility with which the timing of such stereotyped behaviors can be modified is poorly understood. To probe this, we induce adaptive changes to the temporal structure of birdsong. We find that the duration of specific song segments can be modified without affecting the timing in other parts of the song. We derive formal prescriptions for how neural networks can implement such flexible motor timing. We find that randomly connected recurrent networks, a common approximation for how neocortex is wired, do not generally conform to these, though certain...

  20. Dedicated photoreceptor pathways in Drosophila larvae mediate navigation by processing either spatial or temporal cues

    Humberg, Tim-Henning; Bruegger, Pascal; Afonso, Bruno; Zlatic, Marta; Truman, James W.; Gershow, Marc; Samuel, Aravinthan; Sprecher, Simon G.
    To integrate changing environmental cues with high spatial and temporal resolution is critical for animals to orient themselves. Drosophila larvae show an effective motor program to navigate away from light sources. How the larval visual circuit processes light stimuli to control navigational decision remains unknown. The larval visual system is composed of two sensory input channels, Rhodopsin5 (Rh5) and Rhodopsin6 (Rh6) expressing photoreceptors (PRs). We here characterize how spatial and temporal information are used to control navigation. Rh6-PRs are required to perceive temporal changes of light intensity during head casts, while Rh5-PRs are required to control behaviors that allow navigation...

Aviso de cookies: Usamos cookies propias y de terceros para mejorar nuestros servicios, para análisis estadístico y para mostrarle publicidad. Si continua navegando consideramos que acepta su uso en los términos establecidos en la Política de cookies.