109 research outputs found

    Time dependence of current-voltage measurements of c-axis quasiparticle conductivity in 2212-BSCCO mesa structures

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    We report four-point IV measurements of the c-axis conductivity of mesa structures of 2212-BSCCO, using a system with sub-microsecond resolution along with multi-level pulses. These allow a test to be made for the presence of nonequilibrium effects. Our results suggest simple heating alone is important in measurements of this kind.Comment: to appear in proceedings of LT23; submitted to Physica

    Tunable Nb superconducting resonators based upon a Ne-FIB-fabricated constriction nanoSQUID

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    Hybrid superconducting--spin systems offer the potential to combine highly coherent atomic quantum systems with the scalability of superconducting circuits. To fully exploit this potential requires a high quality-factor microwave resonator, tunable in frequency and able to operate at magnetic fields optimal for the spin system. Such magnetic fields typically rule out conventional Al-based Josephson junction devices that have previously been used for tunable high-QQ microwave resonators. The larger critical field of niobium (Nb) allows microwave resonators with large field resilience to be fabricated. Here, we demonstrate how constriction-type weak links, patterned in parallel into the central conductor of a Nb coplanar resonator using a neon focused ion beam (FIB), can be used to implement a frequency-tunable resonator. We study transmission through two such devices and show how they realise high quality factor, tunable, field resilient devices which hold promise for future applications coupling to spin systems

    The Grizzly, October 1, 1982

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    Professors Leave on Sabbatical • New Record Breaker Theme is Photograph • McNamara Displays Hoop Skill • Letter to a Confused Freshman • Ursinus Welcomes New Dean • Letters to the Editor • Opinion: Campus Crime has got to Stop! • It Takes a Trained Eye • GOP\u27s Strategy in \u2782 • The Who Rock JFK • Magnificent Noise • Roving Reporter: What do You Consider to be the Most Positive Aspect of Ursinus College? • I\u27m Turning Japanese • Field Hockey Team Wins 5th Straight • 1982 Ursinus Grizzly Football Stats • Grizzlies Capture First Win! • Grizzlies to Play in Newly Formed Conference • X-Country Streak Broken • Soccer Suffers Setback • Girls\u27 Volleyball Lose Twohttps://digitalcommons.ursinus.edu/grizzlynews/1083/thumbnail.jp

    ALS-associated KIF5A mutations abolish autoinhibition resulting in a toxic gain of function

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    Understandingthepathogenicmechanismsof diseasemutations is critical toadvancingtreatments.ALS-associated mutations in the gene encoding the microtubulemotor KIF5A result in skipping of exon 27 (KIF5ADExon27) and the encoding of a protein with a novel 39 amino acid residue C-terminal sequence. Here, we report that expression of ALS-linked mutant KIF5A results in dysregulated motor activity, cellular mislocalization, altered axonal transport, and decreased neuronal survival. Single-molecule analysis revealed that the altered C terminus of mutant KIF5A results in a constitutively active state. Furthermore,mutant KIF5A possesses altered protein and RNA interactions and its expression results in altered gene expression/splicing. Taken together, our data support the hypothesis that causative ALS mutations result in a toxic gain of function in the intracellular motor KIF5A that disrupts intracellular trafficking and neuronal homeostasis

    HIV in East London: ethnicity, gender and risk. Design and methods

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    BACKGROUND: While men who have sex with men remain the group at greatest risk of acquiring HIV infection in the UK, the number of new diagnoses among heterosexuals has risen steadily over the last five years. In the UK, three-quarters of heterosexual men and women diagnosed with HIV in 2004 probably acquired their infection in Africa. This changing epidemiological pattern is particularly pronounced in East London because of its ethnically diverse population. DESIGN AND METHODS: The objective of the study was to examine the social, economic and behavioural characteristics of patients with HIV infection currently receiving treatment and care in hospitals in East London. The research focused on ethnicity, gender, sexuality, education, employment, housing, HIV treatment, stigma, discrimination, religion, migration and sexual risk behaviour. People diagnosed with HIV infection attending outpatient treatment clinics at St Bartholomew's, the Royal London, Whipp's Cross, Homerton, Newham and Barking hospitals (all in East London) over a 4–6 month period were invited to participate in the study in 2004–2005. Those who agreed to participate completed a confidential, self-administered pen-and-paper questionnaire. During the study period, 2680 patients with HIV attended the outpatient clinics in the six participating hospitals, of whom 2299 were eligible for the study and 1687 completed a questionnaire. The response rate was 73% of eligible patients and 63% of all patients attending the clinics during the survey period. DISCUSSION: A clinic-based study has allowed us to survey nearly 1700 patients with HIV from diverse backgrounds receiving treatment and care in East London. The data collected in this study will provide valuable information for the planning and delivery of appropriate clinical care, social support and health promotion for people living with HIV not only in East London but in other parts of the capital as well as elsewhere in the UK

    Efficiency and safety of varying the frequency of whole blood donation (INTERVAL): a randomised trial of 45 000 donors

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    Background: Limits on the frequency of whole blood donation exist primarily to safeguard donor health. However, there is substantial variation across blood services in the maximum frequency of donations allowed. We compared standard practice in the UK with shorter inter-donation intervals used in other countries. Methods: In this parallel group, pragmatic, randomised trial, we recruited whole blood donors aged 18 years or older from 25 centres across England, UK. By use of a computer-based algorithm, men were randomly assigned (1:1:1) to 12-week (standard) versus 10-week versus 8-week inter-donation intervals, and women were randomly assigned (1:1:1) to 16-week (standard) versus 14-week versus 12-week intervals. Participants were not masked to their allocated intervention group. The primary outcome was the number of donations over 2 years. Secondary outcomes related to safety were quality of life, symptoms potentially related to donation, physical activity, cognitive function, haemoglobin and ferritin concentrations, and deferrals because of low haemoglobin. This trial is registered with ISRCTN, number ISRCTN24760606, and is ongoing but no longer recruiting participants. Findings: 45 263 whole blood donors (22 466 men, 22 797 women) were recruited between June 11, 2012, and June 15, 2014. Data were analysed for 45 042 (99·5%) participants. Men were randomly assigned to the 12-week (n=7452) versus 10-week (n=7449) versus 8-week (n=7456) groups; and women to the 16-week (n=7550) versus 14-week (n=7567) versus 12-week (n=7568) groups. In men, compared with the 12-week group, the mean amount of blood collected per donor over 2 years increased by 1·69 units (95% CI 1·59–1·80; approximately 795 mL) in the 8-week group and by 0·79 units (0·69–0·88; approximately 370 mL) in the 10-week group (p<0·0001 for both). In women, compared with the 16-week group, it increased by 0·84 units (95% CI 0·76–0·91; approximately 395 mL) in the 12-week group and by 0·46 units (0·39–0·53; approximately 215 mL) in the 14-week group (p<0·0001 for both). No significant differences were observed in quality of life, physical activity, or cognitive function across randomised groups. However, more frequent donation resulted in more donation-related symptoms (eg, tiredness, breathlessness, feeling faint, dizziness, and restless legs, especially among men [for all listed symptoms]), lower mean haemoglobin and ferritin concentrations, and more deferrals for low haemoglobin (p<0·0001 for each) than those observed in the standard frequency groups. Interpretation: Over 2 years, more frequent donation than is standard practice in the UK collected substantially more blood without having a major effect on donors' quality of life, physical activity, or cognitive function, but resulted in more donation-related symptoms, deferrals, and iron deficiency. Funding: NHS Blood and Transplant, National Institute for Health Research, UK Medical Research Council, and British Heart Foundation

    The khmer software package: enabling efficient nucleotide sequence analysis

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    The khmer package is a freely available software library for working efficiently with fixed length DNA words, or k-mers. khmer provides implementations of a probabilistic k-mer counting data structure, a compressible De Bruijn graph representation, De Bruijn graph partitioning, and digital normalization. khmer is implemented in C++ and Python, and is freely available under the BSD license at https://github.com/dib-lab/khmer/

    The khmer software package: enabling efficient nucleotide sequence analysis [version 1; referees: 2 approved, 1 approved with reservations]

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    The khmer package is a freely available software library for working efficiently with fixed length DNA words, or k-mers. khmer provides implementations of a probabilistic k-mer counting data structure, a compressible De Bruijn graph representation, De Bruijn graph partitioning, and digital normalization. khmer is implemented in C++ and Python, and is freely available under the BSD license at https://github.com/dib-lab/khmer/
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