Magnetic field suppression of Andreev conductance at superconductor-graphene interfaces

Studying the interplay between superconductivity and quantum magnetotransport in two-dimensional materials has been a topic of interest in recent years. Towards such a goal it is important to understand the impact of magnetic field on the charge transport at the superconductor-normal channel (SN) interface. Here we carried out a comprehensive study of Andreev conductance under weak magnetic fields using diffusive superconductor- graphene Josephson weak links. We observe that the Andreev conductance is suppressed even in magnetic fields far below the upper critical field of the superconductor. The suppression of Andreev conductance depends on and can be minimized by controlling the ramping of the magnetic field. We identify that the key factor behind this suppression is the reduction of the superconducting gap due to the piling of vortices on the superconducting contacts. In devices where superconducting gap at the superconductor-graphene interface is heavily reduced by proximity effect, the enlarged vortex cores overlap quickly with increasing magnetic field, resulting in a rapid decrease of the interfacial gap. However, in weak links with relatively large effective superconducting gap the AR conductance persists up to the upper critical field. Our results provide guidance to the study of quantum material-superconductor systems in presence of magnetic field, where 'survival' of induced superconductivity is critical.Comment: 22 pages, 4 figures. Typos corrected, reference adde

Genetic sampling for estimating density of common species.

Understanding population dynamics requires reliable estimates of population density, yet this basic information is often surprisingly difficult to obtain. With rare or difficult-to-capture species, genetic surveys from noninvasive collection of hair or scat has proved cost-efficient for estimating densities. Here, we explored whether noninvasive genetic sampling (NGS) also offers promise for sampling a relatively common species, the snowshoe hare (Lepus americanus Erxleben, 1777), in comparison with traditional live trapping. We optimized a protocol for single-session NGS sampling of hares. We compared spatial capture-recapture population estimates from live trapping to estimates derived from NGS, and assessed NGS costs. NGS provided population estimates similar to those derived from live trapping, but a higher density of sampling plots was required for NGS. The optimal NGS protocol for our study entailed deploying 160 sampling plots for 4 days and genotyping one pellet per plot. NGS laboratory costs ranged from approximately $670 to$3000 USD per field site. While live trapping does not incur laboratory costs, its field costs can be considerably higher than for NGS, especially when study sites are difficult to access. We conclude that NGS can work for common species, but that it will require field and laboratory pilot testing to develop cost-effective sampling protocols

Old World, New Media: Cross-cultural Explorations with Camera and Analytic Text in Cusco, Peru

Abstract OLD WORLD, NEW MEDIA: CROSS-CULTURAL EXPLORATIONS WITH CAMERA AND ANALYTIC TEXT IN CUSCO, PERU By Scott DuPre Mills, PhD. A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University. Virginia Commonwealth University, 2014 Major Director: Dr. Nicholas A Sharp, Assistant Professor, Department of English This dissertation draws on my field research in Cusco, Peru, documenting Old World methods of making Andean musical instruments. The cross-cultural interactions I engaged in are concretized and documented in the ethnographic film I shot at the time and in my experimentation with original music recorded with these handmade instruments. I have revisited the family that produces these instruments each summer from 2003-2013 and built a relationship that has provided me with an in-depth perspective on the centuries-old tradition of making musical instruments. These instruments afford an exceptionally high quality sound and are created specifically for local professional musicians. My search for an authentic Andean charango occasioned complex association with local artisans, enabling me to perform various roles as a participant in this cross-cultural interaction, from musician and documentary filmmaker to teacher in the summer study program in Peru. Both the fact that VCU students and faculty expressed interest in buying these instruments, and our group expenditures in Peru, enhanced the instrument-making family economically, providing them with the means to expand their production of instruments. Each year after my return back to the United States, I studied closely the documentary footage I had recorded and found that the camera can function as a writing device. In order to explore further and understand conceptually my intuitions, I researched newer theories about camera consciousness and developed my own concepts that are articulated in this dissertation. In the process, I have drawn interdisciplinary connections between Ethnography, Media theory and Anthropological concepts as they relate to human activities in the area of media, art, text. A central theoretical argument in my dissertation underscores the fact that the new media have altered the definition of literacy. In exploring the elements of (traditional and digital) photography, moving image, audio and written text as they define the new intermediatic context, it became apparent that New Media requires an ability to “read” beyond the medium of the written word. This is relevant also for my study of traditional instrument-making in Peru. Because many of the “Old world” methods of creating instruments and music existed outside of a literary (verbal) account or explanation, these methods often became lost or forgotten as new modes of mass production took over. The type of multimedia approach that I am illustrating in this dissertation, mixing traditional with New Media methodologies, has the potential to reconnect us to “Old World” forms via the visual and audio elements that are not directly present in verbal texts. A significant portion of my dissertation explores the introduction and development of the New Media and the devices that connect human beings to the digital domain. My examination foregrounds both the positive and negative implications of the New Media. The inclusion of an anthropological perspective in this discussion provides a broader view of human behavior in relation to the development of communication technology and multimedia

Metabolic characteristics of the ketotic state in the bovine

Gluconeogenic and ketogenic capacities of liver slices as well as metabolite concentrations in plasma and liver were examined in five dairy cows before and after an experimental lactation ketosis, and in four dairy steers treated with phlorizin (P) and/or 1,3-butanediol (BD). Liver biopsies were performed in lactating cows once before parturition and four times within 50 days following parturition. All cows were restricted approximately 15% from ad libitum feed consumption at 14 days postpartum. Four cows became ketotic (average 36 days postpartum) and were characterized during ketosis, compared to early lactation, by: a 66 (+OR-) 6% decrease in propionate, lactate, ALA, ASP, and GLU conversion to glucose; a 47 (+OR-) 6% decrease in the same substrates oxidized to carbon dioxide: and a 70% decrease in (beta)-hydroxybutyrate (BHBA) synthesis when incubated with butyrate. Also, ketotic cows lost body weight at a rate of 3.1 kg/day, and during ketosis, compared to prepartum, showed; a 10 to 15 fold increase in plasma and hepatic ketone bodies (KB), a 10 fold increase in hepatic triglyceride, and a 90% decrease in hepatic glycogen. Much less drastic changes were noted for the nonketotic cow;Liver biopsies were performed on the four steers at the end of each period of a 4 x 4 Latin square trial, and following 6 days of feed restriction in three of the four steers after completion of the Latin square trial. Treatments for the Latin square were: (C) is control, hay plus corn ration; (BD) is C + butanediol added to the ration; (P) is C + twice daily subcutaneous injections of 1 g of phlorizin; and (PBD) is C + P + BD. Glucose production (nmoles substrate converted to glucose/100 mg liver x 1 h) from propionate, lactate, and ASP when fed C was 974, 334, and 101, respectively. Feeding BD increased plasma and hepatic BHBA, and depressed glucose production from propionate (22%) and lactate (35%) compared to C. Phlorizin (P or PBD) or restricted feeding increased glucose production from propionate (32 to 74%), lactate (55 to 160%), and ASP (32-41%). KB (10 mM) plus 1 mM stearate added in vitro, completely negated the increased glucose production due to feed restriction. KB suppress hepatic metabolism, which may be an important contributor to ketosis development

Producers versus regulators? An enquiry into pharmaceutical quality information systems

Given rising costs and declining R&D productivity, the pharmaceutical industry needs information systems and processes that contribute to business efficiency and cost reduction without compromising fundamental quality and safety principles. This study investigated quality information systems in the pharmaceutical industry and the relationship between the industry and its regulators. The data demonstrated a risk-based approach to information management and a quality-by-design philosophy in the industry, aiming to satisfy the needs of product regulators, optimise manufacturing process efficiencies, and give patients reliably consistent medicines and devices. The data also revealed a problematic perception of regulatory oversight, with highly significant correlations between level of regulator contact and ‘difficulty’ with regulators (r=0.92) and between difficulty with regulators and delays in IT implementations (r=0.87).We propose that emerging trends in standards-based interoperability offer a new paradigm for the industry and its regulators

Ship ahoy: all the nice girls love a sailor

https://digitalcommons.ithaca.edu/sheetmusic/1182/thumbnail.jp

Terrestrial Ecosystem Adaptation

In this report we evaluate adaptation issues for natural ecosystems. We will specifically focus on the interactions with the abiotic environment of plants and animals, along with other organisms with which they interact (e.g., disease-causing bacteria and viruses). We further limit ourselves to natural ecosystems in which the predominant vegetation has developed without having been planted, irrigated, or fertilized. Most of the natural lands in the United States are managed by federal or state governments. Agricultural lands— including range grazing lands — are dealt with in a related adaptation report. This will evaluate the potential magnitudes and challenges facing terrestrial ecosystems in the United States in adapting to changing climate over the next 30-50 years. Our report will not address attribution or mitigation of climate change, as these topics have been dealt with in many other forums. We will begin with a brief summary of the current trajectory of the changing climate in the United States, including both temporal and spatial patterns. We will then relate these trends to ecosystem impacts and vulnerabilities