720 research outputs found

    Magnetic Susceptibility of Andreev Bound States in Superfluid 3^3He-B

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    Nuclear magnetic resonance measurements of the magnetic susceptibility of superfluid 3^3He imbibed in anisotropic aerogel reveal anomalous behavior at low temperatures. Although the frequency shift clearly identifies a low-temperature phase as the BB phase, the magnetic susceptibility does not display the expected decrease associated with the formation of the opposite-spin Cooper pairs. This susceptibility anomaly appears to be the predicted high-field behavior corresponding to the Ising-like magnetic character of surface Andreev bound states within the planar aerogel structures.Comment: Resubmitted versio

    Developing Proactive Methods for General Aviation Data Collection

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    Introduction. Over the last 20 years, nearly 40,000 general aviation (GA) aircraft were involved in accidents, roughly 20% of which were fatal. To address this safety concern, scientists have often relied on accident data. Because of the rare nature of accidents, commercial aviation incident and near miss data may prove to be useful sources of safety information. In one such study, the National Transportation Safety Board interviewed GA pilots that were flying near a weather-related accident in pursuit of a different perspective than that of the accident pilot. Interviewing GA pilots about their own weather-related event may provide similar benefits. Method. To understand factors leading GA pilots to encounter adverse weather conditions, pilots involved in an adverse weather encounter were interviewed using a one-hour structured interview. The interview was developed using surveys utilized by National Aeronautics and Space Administration and the Federal Aviation Administration (FAA). In total, 27 pilots who experienced an adverse weather encounter were interviewed, of which 25 were included in the final analysis. Results. Previous studies conducted by the FAA and others found many GA accidents involving flight into adverse weather were categorized as a willful disregard for the rules and regulations of safety; violations as defined by the Human Factors Analysis and Classification System. Contrary to what the accident record seems to suggest, flight into adverse weather may also be influenced by the lack of appreciation/understanding of the hazards associated with adverse weather. Perhaps some encounters with adverse weather were motivated by outside influences or exacerbated by some manner of mechanical failure that may have led to the willful acceptance of unnecessary hazards. Conclusions. These data suggest that current beliefs surrounding flight into adverse weather by GA pilots may be incomplete. The data presented here suggest that additional effort should be placed in training, both ab initio and recurrent. Emphasis should be placed on ensuring a full understanding of the adverse impact of weather, including the recognition of instrument meteorological conditions, icing, convective events, etc. Likewise, with the proliferation of commercial weather products and on-board weather equipment, it may be time to move toward some form of standard weather package that all pilots would review before flying

    Approved but non-funded vaccines: Accessing individual protection

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    AbstractFunded immunization programs are best able to achieve high participation rates, optimal protection of the target population, and indirect protection of others. However, in many countries public funding of approved vaccines can be substantially delayed, limited to a portion of the at-risk population or denied altogether. In these situations, unfunded vaccines are often inaccessible to individuals at risk, allowing potentially avoidable morbidity and mortality to continue to occur. We contend that private access to approved but unfunded vaccines should be reconsidered and encouraged, with recognition that individuals have a prerogative to take advantage of a vaccine of potential benefit to them whether it is publicly funded or not. Moreover, numbers of “approved but unfunded” vaccines are likely to grow because governments will not be able to fund all future vaccines of potential benefit to some citizens. New strategies are needed to better use unfunded vaccines even though the net benefits will fall short of those of funded programs.Canada, after recent delays funding several new vaccine programs, has developed means to encourage private vaccine use. Physicians are required to inform relevant patients about risks and benefits of all recommended vaccines, publicly funded or not. Likewise, some provincial public health departments now recommend and promote both funded and unfunded vaccines. Pharmacists are key players in making unfunded vaccines locally available. Professional organizations are contributing to public and provider education about unfunded vaccines (e.g. herpes zoster, not funded in any province). Vaccine companies are gaining expertise with direct-to-consumer advertising. However, major challenges remain, such as making unfunded vaccines more available to low-income families and overcoming public expectations that all vaccines will be provided cost-free, when many other recommended personal preventive measures are user-pay. The greatest need is to change the widespread perception that approved vaccines should be publicly funded or ignored

    General Aviation Weather Encounter Case Studies

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    This study presents a compilation of 24 cases involving general aviation (GA) pilots’ weather encounters over the continental U.S. The project team interviewed pilots who had experienced a weather encounter, and we examined their backgrounds, flight experience, and weather encounter details. Results from meteorological data analysis for each weather encounter were consistent with findings of larger GA weather accident studies in terms of the types of hazards encountered and flight phase during which the encounters occurred. Investigation of pilot weather products and the sources from which they were obtained revealed a lack of uniformity of pre-flight data sources and underutilization of available en route flight information services. The team used these results to develop a set of pilot weather education and training recommendations intended to reduce the number and severity of weather encounters

    Pharmacological and combined interventions to reduce vaccine injection pain in children and adults systematic review and meta-analysis

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    Background: This systematic review assessed the effectiveness and safety of pharmacotherapy and combined interventions for reducing vaccine injection pain in individuals across the lifespan. Design/Methods: Electronic databases were searched for relevant randomized and quasi-randomized controlled trials. Self-reported pain and fear as well as observer-rated distress were critically important outcomes. Data were combined using standardized mean difference (SMD) or relative risk with 95% confidence intervals (CI). Results: Fifty-five studies that examined breastfeeding (which combines sweet-tasting solution, holding, and sucking), topical anesthetics, sweet-tasting solutions (sucrose, glucose), vapocoolants, oral analgesics, and combination of 2 versus 1 intervention were included. The following results report findings of analyses of critical outcomes with the largest number of participants. Compared with control, acute distress was lower for infants breastfed: (1) during vaccination (n=792): SMD -1.78 (CI, -2.35, -1.22) and (2) before vaccination (n=100): SMD -1.43 (CI, -2.14, -0.72). Compared with control/placebo, topical anesthetics showed benefit on acute distress in children (n=1424): SMD -0.91 (CI, -1.36, -0.47) and self-reported pain in adults (n=60): SMD -0.85 (CI, -1.38, -0.32). Acute and recovery distress was lower for children who received sucrose (n=2071): SMD -0.76 (CI, -1.19, -0.34) or glucose (n=818): SMD -0.69 (CI, -1.03, -0.35) compared with placebo/no treatment. Vapocoolants reduced acute pain in adults [(n=185), SMD -0.78 (CI, -1.08, -0.48)] but not children. Evidence from other needle procedures showed no benefit of acetaminophen or ibuprofen. The administration of topical anesthetics before and breastfeeding during vaccine injections showed mixed results when compared with topical anesthetics alone. There were no additive benefits of combining glucose and non-nutritive sucking (pacifier) compared with glucose or non-nutritive sucking (pacifier) alone or breastfeeding and sucrose compared with breastfeeding or sucrose alone. Conclusions: Breastfeeding, topical anesthetics, sweet-tasting solutions, and combination of topical anesthetics and breastfeeding demonstrated evidence of benefit for reducing vaccine injection pain in infants and children. In adults, limited data demonstrate some benefit of topical anesthetics and vapocoolants
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