172 research outputs found

    Capacity recovery after storage negatively precharged nickel hydrogen cells

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    Tests were conducted to investigate the recovery of capacity lost during open circuit storage of negatively precharged nickel hydrogen batteries. Four Eagle Picher RNH-90-3 cells were used in the tests. Recovery procedures and test results are presented in outline and graphic form

    Capacity loss on storage and possible capacity recovery for HST nickel-hydrogen cells

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    Negatively precharged nickel hydrogen cells will experience a useable capacity loss during extended open circuit storage periods. Some of the lost capacity can be recovered through cycling. Capacity recovery through cycling can be enhanced by cycling at high depths of discharge (DOD). The most timely procedure for recovering the faded capacity is to charge the cell fully and allow the cell to sit open-circuit at room temperature. This procedure seems to be effective in part because of the enlarged structure of the active materials. The compounds that formed during storage at the low electrode potentials can more easily dissolve and redistribute. All of the original capacity cannot be recovered because the lattice structure of the active material is irreversibly altered during storage. The recommendation is to use positively precharged cells activated with 26 percent KOH if possible. In aerospace applications, the benefits of negative precharge are offset by the possibility of delays and storage periods

    An Index to Assess the Sensitivity of Gulf of Mexico Species to Changes in Estuarine Salinity Regimes

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    An index of biological sensitivity to changes in freshwater inflow was developed for 44 species in 22 Gulf of Mexico estuaries for adult and juvenile life stages of fishes and macroinvertebrates. The BioSalinity Index (BSI) provides an innovative approach to quantify estuary-specific sensitivity of organisms to changes in estuarine salinity regimes based upon our knowledge of species salinity habitat preferences, the availability of this preferred habitat, and the relative abundance and distribution of species in time and space. We found that a significant difference exists between adult and juvenile life stage sensitivity, with juveniles exhibiting a lower sensitivity to salinity changes than adults, and that a considerable disparity exists in species-specific sensitivities among Gulf estuaries. Likewise, when the full complement of 44 species-level BSIs are averaged, marked differences in assemblage-wide sensitivity are evident across estuaries. The availability of preferred salinity habitat had a greater influence on the BSI for estuarine species than did their relative abundance and temporal distribution. The BSI was applied by members of a 1995 Gulf of Mexico freshwater inflow workshop to identify a subset of estuaries which appear more sensitive to freshwater inflow changes and are candidates for further study

    Parental notification policies, practices, and impacts in 2000 and 2002

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    Since the enactment of the Drug Free Schools and Communities Act Amendments of 1989, there have been several additional attempts by Congress to address the problem of alcohol abuse on college campuses. In 1 990, Congress passed the Student Right-to-Know and Campus Security Act containing a provision requiring institutions to notify students of the number of arrests for liquor law violations. In the 1998 Higher Education Amendments (HEA), Congress proposed a set of initiatives institutions should take to change the culture of alcohol consumption on college campuses. Entitled The Collegiate Initiative to Reduce Binge Drinking and Illegal Consumption, this particular section of HEA was not law, but only a resolution expressing the sense of Congress. HEA also renamed the Campus Security Act as the Jeanne Clery Disclosure of Campus Security Policy and Campus Crime Statistics Act and expanded the data regarding alcohol violations that institutions were required to report. Prior to the 1998 Amendments, institutions were mandated only to keep and distribute data on the number of arrests for alcohol violations. HEA broadened that requirement to include persons referred for campus disciplinary action for liquor law violations. Finally, HEA included changes to the Family Educational Rights and Privacy Act of 1974 (FERPA) to allow institutions to notify the parents of students under the age of 21, if those students violated Federal, State, or local laws or any rule or policy of the institution governing the use or possession of alcohol. This is now commonly referred to as parental notification

    Group Assessments to Help Build Online Learning Communities in Biomedical Science Distance Learning Programmes

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    Introduction: Biomedical Science distance learning courses offer flexibility in study while in employment. Asynchronous and self-learning approaches are common within such courses and often student-student interaction is limited. The aims of this study were to establish learning communities, develop confidence in participating in online teamwork and foster an appreciation of transferable skills including digital capabilities through remote group activities. Materials and Methods: Two cohorts of students (n = 20/n = 21) were enrolled in a microbiology module of an IBMS accredited MSc distance learning course. Groups of 4–5 students produced a digital output relating to current global infection-related issues, namely, assignment 1, production of a slide deck, which peers could use as learning resources and assignment 2, a voiceover PowerPoint debate, and infographic, voting assessment and peer/self-marking. Students also prepared reflections using written format and a FlipGrid video-recording. A qualitative content analysis was conducted on reflections from all students. Students completed a pre- and post-assignment survey focused on the development of transferable skills for the biomedical sector. Results: Students’ skills and confidence increased following completion of the group assignment, as evident from the pre- and post-questionnaire responses, namely, possession of digital skills and digital creation abilities (29% v 83%), applying for jobs which require digital skills (54% v 89%), talking about examples of using digital media during job interviews (21% v 78%) and demonstration of creativity during assignment tasks (33% v 90%). Critical thinking was more commonly demonstrated during the debate in comparison to the slide deck activity (p = 0.001). The importance of developing digital skills, was higher following completion of the group activities (p = 0.03). Students reflected on the value of the group activities in relation to knowledge acquisition (85%, 86%), collegiality (70%, 71%), digital skills development (80%, 90%), the fact that the activities were enjoyable (70%, 67%) and the development of peer interaction and support (50%, 67%) in relation to assignment 1 and 2, respectively. Discussion: Increasingly digital technologies are being used in the healthcare sector resulting in updated HCPC Standards of Proficiency. This study highlights that virtual group activities promote the establishment of supportive learning communities and the development of transferable skills including digital capabilities for application within the biomedical science workplace

    Proteomics Analysis and Protein Expression during Sporozoite Excystation of Cryptosporidium parvum (Coccidia, Apicomplexa)

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    Cryptosporidiosis, caused by coccidian parasites of the genus Cryptosporidium, is a major cause of human gastrointestinal infections and poses a significant health risk especially to immunocompromised patients. Despite intensive efforts for more than 20 years, there is currently no effective drug treatment against these protozoa. This study examined the zoonotic species Cryptosporidium parvum at two important stages of its life cycle: the non-excysted (transmissive) and excysted (infective) forms. To increase our understanding of the molecular basis of sporozoite excystation, LC-MS/MS coupling with a stable isotope N-terminal labeling strategy using iTRAQ (TM) reagents was used on soluble fractions of both non-excysted and excysted sporozoites, i.e. sporozoites both inside and outside oocysts were examined. Sporozoites are the infective stage that penetrates small intestinal enterocytes. Also to increase our knowledge of the C. parvum proteome, shotgun sequencing was performed on insoluble fractions from both non-excysted and excysted sporozoites. In total 303 C. parvum proteins were identified, 56 of which, hitherto described as being only hypothetical proteins, are expressed in both excysted and non-excysted sporozoites. Importantly we demonstrated that the expression of 26 proteins increases significantly during excystation. These excystation-induced proteins included ribosomal proteins, metabolic enzymes, and heat shock proteins. Interestingly three Apicomplexa-specific proteins and five Cryptosporidium-specific proteins augmented in excysted invasive sporozoites. These eight proteins represent promising targets for developing vaccines or chemotherapies that could block parasite entry into host cells

    beta-Hydroxy-beta-methylbutyrate free acid reduces markers of exercise-induced muscle damage and improves recovery in resistance-trained men

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    The purpose of the present study was to determine the effects of short-term supplementation with the free acid form of beta-hydroxy-beta-methylbutyrate (HMB-FA) on indices of muscle damage, protein breakdown, recovery and hormone status following a high-volume resistance training session in trained athletes. A total of twenty resistance-trained males were recruited to participate in a high-volume resistance training session centred on full squats, bench presses and dead lifts. Subjects were randomly assigned to receive either 3 g/d of HMB-FA or a placebo. Immediately before the exercise session and 48 h post-exercise, serum creatine kinase (CK), urinary 3-methylhistadine (3-MH), testosterone, cortisol and perceived recovery status (PRS) scale measurements were taken. The results showed that CK increased to a greater extent in the placebo (329%) than in the HMB-FA group (104%) (P=0.004, d=1.6). There was also a significant change for PRS, which decreased to a greater extent in the placebo (9.1 (SEM 0.4) to 4.6 (SEM 0.5)) than in the HMB-FA group (9.1 (SEM 0.3) to 6.3 (SEM 0.3)) (P=0.005, d = -0.48). Muscle protein breakdown, measured by 3-MH analysis, numerically decreased with HMB-FA supplementation and approached significance (P=0.08, d = 0.12). There were no acute changes in plasma total or free testosterone, cortisol or C-reactive protein. In conclusion, these results suggest that an HMB-FA supplement given to trained athletes before exercise can blunt increases in muscle damage and prevent declines in perceived readiness to train following a high-volume, muscle-damaging resistance-training session

    Three Drinking-Water–Associated Cryptosporidiosis Outbreaks, Northern Ireland

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    Three recent drinking-water–associated cryptosporidiosis outbreaks in Northern Ireland were investigated by using genotyping and subgenotyping tools. One Cryptosporidium parvum outbreak was caused by the bovine genotype, and two were caused by the human genotype. Subgenotyping analyses indicate that two predominant subgenotypes were associated with these outbreaks and had been circulating in the community
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