621 research outputs found

    Closed-form evaluation of 2D static lattice sums

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    In the present paper, employing properties of the complete elliptic integrals of the first and second kind, we deduce closed-form formulae for the lattice sums and other new formulae. Applications to the effective properties of regular and random composites are discussed. We also discuss the Eisenstein summation method and the Rayleigh method used in computations

    Survey Research On The Relationship Between Immediacy Behaviors, Communication Competency, And Philanthropic Success

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    Thesis (M.A.) University of Alaska Fairbanks, 2008In this study, 124 Alaskan-based development professionals responded to a questionnaire concerning their perceived communicative competency and their self-reported immediacy behaviors in relation to fund-raising success. Several key findings resulted. First, in relation to the role of communication competency, this study suggests that fund-raising success is driven by the donor, rather than the fund-raising professional's communication competency. Second, the study found that successful fund-raising professionals have higher levels of verbal and non-verbal immediacy behaviors (when compared to non-successful fundraisers). Third, this study finds that development professionals who work in the geographic region of Northern Alaska use less verbal immediacy behaviors than those development professionals who represent regions in south-central, southeast, interior, and statewide districts. Finally, the demographics presented in this study support the priority need for Alaskan fundraisers to continue to grow their donor base since only 14% of the respondents reported that they are reliant on face-to-face meetings with donors for gifts in the range of 18,00018,000--300,000. This can be attributed to the "newness" of philanthropic work in Alaska and highlights the incredible growth potential for this field in the future

    Import of cytochrome c heme lyase into mitochondria

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    Cytochrome c heme lyase (CCHL) catalyses the covalent attachment of the heme group to apocytochrome c during its import into mitochondria. The enzyme is membrane-associated and is located within the intermembrane space. The precursor of CCHL synthesized in vitro was efficiently translocated into isolated mitochondria from Neurospora crassa. The imported CCHL, like the native protein, was correctly localized to the intermembrane space, where it was membrane-bound. As with the majority of mitochondrial precursor proteins, CCHL uses the MOM19-GIP receptor complex in the outer membrane for import. In contrast to proteins taking the general import route, CCHL was imported independently of both ATP-hydrolysis and an electrochemical potential as external energy sources. CCHL which lacks a cleavable signal sequence apparently does not traverse the inner membrane to reach the intermembrane space; rather, it translocates through the outer membrane only. Thus, CCHL represents an example of a novel, 'non-conservative' import pathway into the intermembrane space, thereby also showing that the import apparatus in the outer membrane acts separately from the import machinery in the inner membrane

    A mutant of Neurospora crassa deficient in cytochrome c heme lyase activity cannot import cytochrome c into mitochondria

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    The nuclear cyt-2-1 mutant of Neurospora crassa is characterized by a gross deficiency of cytochrome c (Bertrand, H., and Collins, R. A. (1978) Mol. Gen. Genet. 166, 1-13). The mutant produces mRNA that can be translated into apocytochrome c in vitro. Apocytochrome c is also synthesized in vivo in cyt-2-1, but it is rapidly degraded and thus does not accumulate in the cytosol. Mitochondria from wild-type cells bind apocytochrome c made in vitro from either wild-type or cyt-2-1 mRNA and convert it to holocytochrome c. This conversion depends on the addition of heme by cytochrome c heme lyase and is coupled to translocation of cytochrome c into the intermembrane space. Mitochondria from the cyt-2-1 strain are deficient in the ability to bind apocytochrome c. They are also completely devoid of cytochrome c heme lyase activity. These defects explain the inability of the cyt-2-1 mutant to convert apocytochrome c to the holo form and to import it into mitochondria

    Sports Heart Monitors as Reliable Diagnostic Tools for Training Control and Detecting Arrhythmias in Professional and Leisure-Time Endurance Athletes: An Expert Consensus Statement

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    There are countless types of portable heart rate monitoring medical devices used variously by leisure-time exercisers, professional athletes, and chronically ill patients. Almost all the currently used heart rate monitors are capable of detecting arrhythmias, but this feature is not widely known or used among their millions of consumers. The aims of this paper were as follows: (1) to analyze the currently available sports heart rate monitors and assess their advantages and disadvantage in terms of heart rate and rhythm monitoring in endurance athletes; (2) to discuss what types of currently available commercial heart rate monitors are most convenient/adjustable to the needs of different consumers (including occasionally physically active adults and cardiac patients), bearing in mind the potential health risks, especially heart rhythm disturbances connected with endurance training; (3) to suggest a set of "optimal" design features for next-generation smart wearable devices based on the consensus opinion of an expert panel of athletes, coaches, and sports medicine doctors. Ninety-two experts aged 20 years and over, involved in endurance sports on a daily basis, were invited to participate in consensus-building discussions, including 56 long-distance runners, 18 cyclists, nine coaches, and nine physicians (sports medicine specialists, cardiologists, and family medicine doctors). The overall consensus endorsed by these experts indicates that the "optimal" sports heart rate monitor should be a one-piece device of the smartwatch type (with two or more electrodes), with integrated smartphone features, and able to collect and continually transmit data without exhibiting artifacts. It should continuously record at least a single-lead electrocardiography, send an alert after an unexpected fall, be of reasonable weight, come at an affordable price, and be user friendly

    Epidemiology of physical activity in adult Polish population in the second decade of the 21st century. Results of the NATPOL 2011 study

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    Objectives: The aim of the study was to assess physical activity (PA) level in a representative sample of Polish adults.Materials and Methods: A cross-sectional analysis was performed among 2413 randomly selected individuals (51.5% women) aged 18-79 years, who participated in the Nationwide Study of Occurrence of Risk Factors of Cardiovascular Diseases NATPOL 2011 (March-July 2011). The study procedures consisted of a questionnaire as well as of anthropometric, blood pressure and biochemical measurements. Leisure-time, occupational and commuting PA were assessed by the use of a questionnaire interview. Results: About 48.2% of adults do exercise for at least 30 minutes on most days of a week. About 11% of the respondents declare a sedentary lifestyle. About 26.5% of working population report hard physical work, while sedentary work is reported by 47.6% of the employed participants. Active commuting is declared by 27.3% of working/studying population. About 47.2%, 36.6%, and 15.3% spend 30 min per day, respectively, on this kind of PA. Conclusions: PA level of more than half of Polish adults is still not satisfactory. Promotion of an active lifestyle should concern mainly leisure-time and commuting PA with paying special attention to substantial differences in various socio-demographic groups

    Biochemical and hematological changes following the 120-km open-water marathon swim

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    Data on physiological effects and potential risks of a ultraendurance swimming are scarce. This report presents the unique case of a 61-year old athlete who completed a non-stop open-water 120-km ultramarathon swim on the Warta River, Poland. Pre-swimming examinations revealed favorable conditions (blood pressure, 110/70 mmHg; rest heart rate, 54 beats/minute, ejection fraction, 60%, 20.2 metabolic equivalents in a maximal exercise test). The swimming time and distance covered were 27 h 33 min and 120 km, respectively. Blood samples for hematological and biochemical parameters were collected 30 min, 4 hrs, 10 hrs and 8 days after the swim. The body temperature of the swimmer was 36.7°C before and 35.1°C after the swim. The hematological parameters remained within the reference range in the postexercise period except for leucocytes (17.5 and 10.6 x G/l noted 30 minutes and 4 hours after the swim, respectively). Serum urea, aspartate aminotransferase and C-reactive protein increased above the reference range reaching 11.3 mmol/l, 1054 nmol/l/s and 25.9 mg/l, respectively. Symptomatic hyponatremia was not observed. Although the results demonstrate that an experienced athlete is able to complete an ultra-marathon swim without negative health consequences, further studies addressing the potential risks of marathon swimming are required.
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