167 research outputs found

    The Roles of Exercise Habits, Gender Stereotype of Exercise, and Self-Esteem in Sexual Victimization

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    Anecdotal evidence suggests that women who exercise regularly increase not only their physical strength but also their mental strength, which has been conceptualized as self-confidence, assertiveness, and self-esteem. Empirical investigation into this area of research, however, is scarce. One study found that self-reported victimization rates of female athletes were significantly lower when compared with another study\u27s female non-athlete sample. More recently, research found significant differences in levels of self-esteem and sexual victimization rates between female collegiate varsity athletes and the general female college population. The current study is a subsequent analysis of the data used in the aforementioned study. Data were collected from an undergraduate population of females in a mid-sized western university. Subjects were drawn from four varsity athletic teams and from two general classes. Measures of sexual victimization, self-esteem, and exercise habits were administered. The current study found that frequency of exercise, intensity of exercise, duration of exercise, and self-esteem, were not related to victimization at a statistically significant level. This was true for the sample as a whole, and when varsity athletes and non-varsity athletes were considered separately. Though it did not reach statistical significance, further analysis revealed that varsity athletes were three times less likely to report victimization than non-varsity athletes. Gender stereotype of exercise was not able to predict victimization scores over and above frequency of exercise, intensity of exercise, duration of exercise, and self-esteem, among non-varsity athletes. The variable of gender stereotype of exercise demonstrated that subjects who reported female-stereotyped exercises were three times more likely than those who participated in gender-neutral exercises, and eight times more likely than those who participated in male-stereotyped exercises, to endorse statements of sexual victimization. These results, however, were not statistically significant. Though neither research hypothesis was supported, analyses indicated that further investigation into variables that buffer one against sexual victimization relative to self-esteem and choice of exercise habits is merited

    Angiogenesis in tissue engineering : Breathing life into constructed tissue substitutes

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    Long-term function of three-dimensional (3D) tissue constructs depends on adequate vascularization after implantation. Accordingly, research in tissue engineering has focused on the analysis of angiogenesis. For this purpose, 2 sophisticated in vivo models (the chorioallantoic membrane and the dorsal skinfold chamber) have recently been introduced in tissue engineering research, allowing a more detailed analysis of angiogenic dysfunction and engraftment failure. To achieve vascularization of tissue constructs, several approaches are currently under investigation. These include the modification of biomaterial properties of scaffolds and the stimulation of blood vessel development and maturation by different growth factors using slow-release devices through pre-encapsulated microspheres. Moreover, new microvascular networks in tissue substitutes can be engineered by using endothelial cells and stem cells or by creating arteriovenous shunt loops. Nonetheless, the currently used techniques are not sufficient to induce the rapid vascularization necessary for an adequate cellular oxygen supply. Thus, future directions of research should focus on the creation of microvascular networks within 3D tissue constructs in vitro before implantation or by co-stimulation of angiogenesis and parenchymal cell proliferation to engineer the vascularized tissue substitute in situ

    Vivostat Platelet-Rich Fibrin® for Complicated or Chronic Wounds-A Pilot Study

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    Vivostat Platelet-Rich Fibrin® (PRF) is an autologous platelet concentrate used for the local treatment of chronic or complicated wounds. Still, its application for this indication is not evidence-based. Therefore, we performed this monocentric retrospective pilot study investigating the clinical outcome of a local treatment of chronic or complicated wounds in 35 patients (23 male, 12 female, mean age 68.7 years) treated with Vivostat PRF®. This study population is the largest among published studies analyzing the clinical efficacy of Vivostat PRF® on chronic wounds so far. Using the perpendicular method we divided the wounds into three sizes (30 cm2). The clinical efficacy of the Vivostat PRF treatment was the primary endpoint and was divided into three groups of increasing degrees of wound improvement: (1) no improvement of the wound (wound area was not reduced > 10% under Vivostat PRF® treatment), (2) improvement of the wound (reduced area > 10% under Vivostat PRF® treatment) and (3) complete epithelialization (wounds that were completely re-epithelialized after Vivostat PRF® treatment). We included patients' diagnosis and concomitant diseases (peripheral arterial occlusive disease (PAOD)), chronic venous insufficiency (CVI)), diabetic foot syndrome (DFS)) in our data analysis in order to investigate their potential impact on the wound healing capacity of Vivostat PRF®. Our results show that in the entire study population, 13 out of 35 (37.1%) patients experienced wound improvement and 14 out of 35 (40%) patients showed complete epithelialization of their wound under Vivostat PRF® treatment. In summary, 77.1% of the treated patients benefited from the Vivostat PRF® therapy

    Ultrafine-scale magnetostratigraphy of marine ferromanganese crust

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    http://geology.geoscienceworld.org/content/39/3/227.full.pdf+htmlHydrogenetic ferromanganese crusts are iron-manganese oxide chemical precipitates on the seafloor that grow over periods of tens of millions of years. Their secular records of chemical, mineralogical, and textural variations are archives of deep-sea environmental changes. However, environmental reconstruction requires reliable high-resolution age dating. Earlier chronological methods using radiochemical and stable isotopes provided age models for ferromanganese crusts, but have limitations on the millimeter scale. For example, the reliability of 10Be/9Be chronometry, commonly considered the most reliable technique, depends on the assumption that the production and preservation of 10Be are constant, and requires accurate knowledge of the 10Be half-life. To overcome these limitations, we applied an alternative chronometric technique, magnetostratigraphy, to a 50-mm-thick hydrogenetic ferromanganese crust (D96-m4) from the northwest Pacific. Submillimeter-scale magnetic stripes originating from approximately oppositely magnetized regions oriented parallel to bedding were clearly recognized on thin sections of the crust using a high-resolution magnetometry technique called scanning SQUID (superconducting quantum interference device) microscopy. By correlating the boundaries of the magnetic stripes with known geomagnetic reversals, we determined an average growth rate of 5.1 ± 0.2 mm/m.y., which is within 16% of that deduced from the 10Be/9Be method (6.0 ± 0.2 mm/m.y.). This is the finest-scale magnetostratigraphic study of a geologic sample to date. Ultrafine-scale magnetostratigraphy using SQUID microscopy is a powerful new chronological tool for estimating ages and growth rates for hydrogenetic ferromanganese crusts. It provides chronological constraints with the accuracy promised by the astronomically calibrated magnetostratigraphic time scale (1–40 k.y.).Japan Society for the Promotion of Science (Grant-in-Aid for Scientific Research (21654071))National Science Foundation (U.S.) (Collaboration in Mathematical Geosciences Program

    “Mixed Blood” Indians: Racial Reconstruction in the Early South

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    Ratiometric imaging of calcium during ischemia-reperfusion injury in isolated mouse hearts using Fura-2

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    Abstract Background We present an easily implementable method for measuring Fura-2 fluorescence from isolated mouse hearts using a commercially available switching light source and CCD camera. After calibration, it provides a good estimate of intracellular [Ca2+] with both high spatial and temporal resolutions, permitting study of changes in dispersion of diastolic [Ca2+], Ca2+ transient dynamics, and conduction velocities in mouse hearts. In a proof-of-principle study, we imaged isolated Langendorff-perfused mouse hearts with reversible regional myocardial infarctions. Methods Isolated mouse hearts were perfused in the Landendorff-mode and loaded with Fura-2. Hearts were then paced rapidly and subjected to 15 minutes of regional ischemia by ligation of the left anterior descending coronary artery, following which the ligation was removed to allow reperfusion for 15 minutes. Fura-2 fluorescence was recorded at regular intervals using a high-speed CCD camera. The two wavelengths of excitation light were interleaved at a rate of 1 KHz with a computer controlled switching light source to illuminate the heart. Results Fura-2 produced consistent Ca2+ transients from different hearts. Ligating the coronary artery rapidly generated a well defined region with a dramatic rise in diastolic Ca2+ without a significant change in transient amplitude; Ca2+ handling normalized during reperfusion. Conduction velocity was reduced by around 50% during ischemia, and did not recover significantly when monitored for 15 minutes following reperfusion. Conclusions Our method of imaging Fura-2 from isolated whole hearts is capable of detecting pathological changes in intracellular Ca2+ levels in cardiac tissue. The persistent change in the conduction velocities indicates that changes to tissue connectivity rather than altered intracellular Ca2+ handling may be underlying the electrical instabilities commonly seen in patients following a myocardial infarction.</p
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