Search

Experimental determination of the cross sections of proton capture on radioactive nuclei is extremely difficult. Therefore, it is of substantial interest for the understanding of the production of the p-nuclei. For the first time, a direct measurement of proton-capture cross sections on stored, radioactive ions became possible in an energy range of interest for nuclear astrophysics. The experiment was performed at the Experimental Storage Ring (ESR) at GSI by making use of a sensitive method to measure (p,γ) and (p,n) reactions in inverse kinematics. These reaction channels are of high relevance for the nucleosyn-thesis processes in supernovae, which are among the most violent explosions in the universe and are not yet well understood. The cross section of the 118Te(p,γ) reaction has been measured at energies of 6 MeV/u and 7 MeV/u. The heavy ions interacted with a hydrogen gas jet target. The radiative recombination process of the fully stripped 118Te ions and electrons from the hydrogen target was used as a luminosity monitor. An overview of the experimental method and preliminary results from the ongoing analysis will be presented.

Medusae can be conspicuous and abundant members of seafloor communities in deep-sea benthic boundary layers. The epibenthic trachymedusa, Ptychogastria polaris Allman, 1878 (Hydrozoa: Trachylina: Ptychogastriidae) occurs in the cold, high latitude systems of both the northern and southern hemispheres, with a circumpolar distribution in Arctic and sub-Arctic areas, and disjunct reports of a few individuals from Antarctica. In January-February 2010, during benthic megafaunal photosurveys in three subpolar fjords along the West Antarctic Peninsula (Andvord, Flandres and Barilari Bays), P. polaris was recorded in Antarctic Peninsula waters. The trachymedusa, identified from megacore-collected specimens, was a common component of the epifauna in the sediment floored basins at 436-725 m depths in Andvord and Flandres Bays, reaching densities up to 13 m-2, with mean densities in individual basins ranging from 0.06 to 4.19 m-2. These densities are 2 to 400-fold higher than previously reported for P. polaris in either the Arctic or Antarctic. This trachymedusa had an aggregated distribution, occurring frequently in Andvord Bay, but was often solitary in Flandres Bay, with a distribution not significantly different from random. Epibenthic individuals were similar in size, typically measuring 15-25 mm in bell diameter. A morphologically similar trachymedusa, presumably the same species, was also observed in the water column near the bottom in all three fjords. This benthopelagic form attained abundances of up to 7 m-2 of seafloor; however, most P. polaris (~ 80%), were observed on soft sediments. Our findings indicate that fjords provide a prime habitat for the development of dense populations of P. polaris, potentially resulting from high and varied food inputs to the fjord floors. Because P. polaris resides in the water column and at the seafloor, large P. polaris populations may contribute significantly to pelagic-benthic coupling in the WAP fjord ecosystems.

Fatty acid concentrations expressed as percentages of total fatty acid pools in seston, stage V copepodites of Calanus finmarchicus, adults of the euphausiid Meganyctiphanes norvegica, and the physonect siphonophore Nanomia cara were used to elucidate trophic links in Georges Basin and Oceanographer Canyon in September 2003. Seston at both locations was refractory and comprised mainly of saturated fatty acids. Phytoplankton did not contribute significantly to the fatty acid composition of seston or higher trophic levels. Only four fatty acids, i.e. 14:0, 16:0, 16:1 (n–7) and 18:1 (n–7), were transferred from seston to C. finmarchicus or M. norvegica, which suggested weak trophic interactions. Fatty acids transferred from the two species of crustaceans to N. cara included the same four fatty acids, along with three polyunsaturated fatty acids found in relatively high concentrations in both crustaceans, i.e. 20:3 (n–6), 20:5 (n–3) and 22:6 (n–3). In addition, 18:1 (n–9), which occurred in relatively high concentrations only in M. norvegica, and 18:0 and 18:2 (n–6), which were found in low concentrations in both crustaceans, also appeared to be transferred to N. cara. Overall, fatty acid trophic markers proved useful for identifying trophic links to N. cara.

In this article, we propose a cross-pollination of two prominent lines of educational thought: open education (OE) and threshold concepts (TCs). Open education has gained an increased profile through the growing popularity of open educational resources (OER) and massive online open courses (MOOCs). Educators who create or make use of such resources, or employ related open educational practices (OEP), are often suggested to have a transformative impact in educational settings. In recent years, educational research has increasingly discussed learning as a process of attaining or crossing certain conceptual thresholds, which involve such a significant shift that the learner eventually achieves a different and deeper understanding of core disciplinary knowledge, even a new identity. Of the eight characteristics of TCs identified in the core literature of this theory, we consider that three in particular offer the maximum potential for understanding the evolution of teachers towards the open educator identity: transformative, troublesome and liminal. This work presents a theoretical framework that includes the transformative impact on identity in the process of becoming an open educator, the troublesomeness inherent in this evolution and the liminal space through which the evolving teachers progress. It is argued that a focus on the development of open educator identity aligns with current reflective approaches to working on teachers' professional identity, and at the same time supports a focus on teachers' commitment to a democratic approach to education, which is necessary in neoliberal times.

Abstract Background Age-related neurodegenerative diseases share a number of important pathological features, such as accumulation of misfolded proteins as amyloid oligomers and fibrils. Recent evidence suggests that soluble amyloid oligomers and not the insoluble amyloid fibrils may represent the primary pathological species of protein aggregates. Results We have produced several monoclonal antibodies that specifically recognize prefibrillar oligomers and do not recognize amyloid fibrils, monomer or natively folded proteins. Like the polyclonal antisera, the individual monoclonals recognize generic epitopes that do not depend on a specific linear amino acid sequence, but they display distinct preferences for different subsets of prefibrillar oligomers. Immunological analysis of a number of different prefibrillar Aβ oligomer preparations show that structural polymorphisms exist in Aβ prefibrillar oligomers that can be distinguished on the basis of their reactivity with monoclonal antibodies. Western blot analysis demonstrates that the conformers defined by the monoclonal antibodies have distinct size distributions, indicating that oligomer structure varies with size. The different conformational types of Aβ prefibrillar oligomers can serve as they serve as templates for monomer addition, indicating that they seed the conversion of Aβ monomer into more prefibrillar oligomers of the same type. Conclusions These results indicate that distinct structural variants or conformers of prefibrillar Aβ oligomers exist that are capable of seeding their own replication. These conformers may be analogous to different strains of prions.

The health and athletic performance benefits of strength training for adolescents have increased the demand for the development and use of strength and conditioning facilities (SCFs) within the high school setting. Despite the growing prevalence of these facilities, research on high school SCFs is limited. Therefore, the purpose of this study was to investigate the space, equipment, usage, and staffing patterns of SCFs in the state of Texas. This examination provided descriptive data on SCFs' space, equipment, usage, and staffing patterns based upon the state athletic governing body's six-tier classification level. Significant differences in SCFs' size and available equipment were determined; as well, facility usage for athletics (99.2%), physical education (24.5%), and community (30.6%) was determined. These results are indicative of the need for additional research on high school SCFs for the establishment of better school standards and best practices.

This theoretical study proposes a set of 'transformative insights' that transcend disciplinary boundaries and point to a common educational foundation at undergraduate level. It involved a review of disciplinary threshold concepts, followed by thematic analyses of institutional and programme level graduate profiles from New Zealand universities. Twelve common clusters of graduate attributes were identified, but their potential as cross-disciplinary threshold concepts was found to be problematic. This led to the alternative proposal that six transformative insights occur during undergraduate education: discernment of underlying beliefs, assumptions, values and expectations; epistemological positioning; linguistic nuance; engagement as a learner; thinking critically, analytically and creatively; and ethical awareness and integrity. Transformative insights reflect a synthesis of threshold concepts and graduate attributes, and support institution-wide approaches to teaching, learning and curriculum development. Further research to establish an empirical basis for the utility of transformative insights and explore their relationship to disciplinary threshold concepts is proposed.

The health and athletic performance benefits of strength training for adolescents have increased the demand for the development and use of strength and conditioning facilities (SCFs) within the high school setting. Despite the growing prevalence of these facilities, research on high school SCFs is limited. Therefore, the purpose of this study was to investigate the space, equipment, usage, and staffing patterns of SCFs in the state of Texas. This examination provided descriptive data on SCFs' space, equipment, usage, and staffing patterns based upon the state athletic governing body's six-tier classification level. Significant differences in SCFs' size and available equipment were determined; as well, facility usage for athletics (99.2%), physical education (24.5%), and community (30.6%) was determined. These results are indicative of the need for additional research on high school SCFs for the establishment of better school standards and best practices., The benefits of strength training for adolescents on both athletic performance (Harries et al., 2012) and general health (Smith et al., 2014) have been well documented. As such, the demand [...]

Background: Femoral fragility fractures in older adults can result in devastating loss of physical function and independence. Skeletalmuscle atrophy likely contributes to disability. The purpose of this study was to characterize the change in skeletalmuscle mass, investigate the relationship with malnutrition and physical function, and identify risk factors for skeletal muscle loss. Methods: Adults ≥65 years of age who were treated with operative fixation of an isolated femoral fragility fracture were enrolled in this multicenter, prospective observational study. Skeletal muscle mass was assessed within 72 hours of admission using multifrequency bioelectrical impedance analysis, which was repeated at 6 weeks, 3 months, and 6 months. Sarcopenia was defined by sex-specific cutoffs for the appendicular skeletal muscle mass index. The Mini Nutritional Assessment was used to measure nutritional status at the time of injury. Physical function was measured using the Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function domain. Linear mixed models were used to evaluate changes in skeletal muscle mass and PROMIS Physical Function scores over time and to evaluate factors associated with skeletal muscle mass changes. Results: Ninety participants (74% female) with a mean age of 77.6 ± 9.0 years were enrolled. At the time of injury, 30 (33%) were sarcopenic and 44 (49%) were at risk for malnutrition or had malnutrition. Older age was associated with lower skeletal muscle mass (age of ≥75 versus <75 years: least squares mean [and standard error],23.3 ± 1.6 kg; p = 0.042). From the time of injury to 6 weeks, participants lost an average of 2.4 kg (9%) of skeletal muscle mass (95% confidence interval [CI] = -3.0 to -1.8 kg; p < 0.001). This early loss did not recover by 6 months (1.8 kg persistent loss compared with baseline [95% CI = -2.5 to -1.1 kg]; p < 0.001). Participants with normal nutritional status lost more skeletal muscle mass from baseline to 6 weeks after injury compared with those with malnutrition (1.3 kg more loss [standard error, 0.6 kg]; p = 0.036). A 1-kg decrease in skeletal muscle mass was associated with an 8-point decrease in the PROMIS Physical Function (model parameter estimate, 0.12 [standard error, 0.04]; p = 0.002). Conclusions: We found that older adults with femoral fragility fractures lost substantial skeletal muscle mass and physical function. Participants with adequate baseline nutrition actually lost more muscle mass than those who were malnourished, indicating that future investigations of interventions to prevent muscle loss should focus on older adults regardless of nutritional status. Level of Evidence: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Key Clinical Message: The robotic modified Strong procedure is a safe and effective approach for surgical management of superior mesenteric artery syndrome in properly selected patients. Superior mesenteric artery syndrome is a rare syndrome of small bowel obstruction resulting from vascular compression of the duodenum. Here we present our modification of a robotic Strong procedure for the surgical management of SMA syndrome. This procedure is a safe and effective approach for management in properly selected patients. [ABSTRACT FROM AUTHOR]