1,019 research outputs found

    Recurring Sacral Stress Fractures in the Male Distance Runner

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    Reccurring Sacral Stress Fractures in the Male Distance Runner Waugh TJ, Stoller GL, Brooks EK, Dailey SW: Miami University Oxford, Ohio Background: A twenty year old male collegiate distance runner (170 cm and 62 kg) complained of low back pain in March 2015. The patient reported right sided low back tightness that felt like a bad spasm traveling from the lower back down into the lower leg. History of this runner revealed a non-displaced stress fracture in the left sacral ala with a stress reaction on the right sacral ala in November 2013. In April 2014, the distance runner possessed yet another sacral stress fracture. In March 2015, an assessment was made that the patient presented an acute case of piriformis syndrome due to lack of athletic participation. As two weeks went by with no positive results through rehabilitation, worsening pain, and given the pre-existing conditions of the patient, the Team Physician ordered an MRI. Differential Diagnosis: It is possible that the runner could have had an acute disc herniation, muscle strain, degenerative disc disease, or spondylolisthesis. A vertebral compression fracture, sacroiliac joint dysfunction, lumbar facet arthropathy, and sciatica are all differential diagnoses that the clinicians in this case needed to be aware of. It is also important to assess the possibilities of a lumbosacral strain and a sacroiliac joint sprain. Treatment: The MRI report revealed a high grade stress reaction in the right sacral ala. A non-displaced stress fracture in the right superior portion of the left sacral ala was also discovered. The patient was told to rest without any exercise for four to six weeks. After the stress fracture was resolved, the athlete has been encouraged not to participate in any repeated load-bearing types of activities until the source of the problem has been identified. Uniqueness: There is an uncommon nature of sacral stress fractures in males. It is important to realize that individuals who are constantly participating in repeating load-bearing activities are more prone to sacral stress fractures. Sacral stress fractures normally present themselves in women who have the female athlete triad. Research has shown that the influence of energy balance and hormonal fluctuations are significant factors associated with injuries in amenorrheic female athletes. The testosterone levels in young men normally lead to healthy and strong bones. This case report is a prime example that has the potential to teach clinicians all over to always look at the big picture and keep in mind all of the possible differential diagnoses. Conclusions: Physician's have hypothesized that the calcium level in this patient is too high which is causing parathyroid levels to decrease, resulting in low bone density. Since calcium and the parathyroid hormone have an inverse relationship, moderation between the two is essential. However, if one is too high, the other is too low decreasing bone density. Another hypothesis is that low testosterone levels in the patient are causing low bone density. This rare case is far from over as there is numerous investigative work to still be done. Clinical Application: Correctly diagnosing a sacral stress fracture is very difficult due to the wide range of differential diagnoses that its symptoms can present. Clinicians should never rule out the possibility of a sacral stress fracture when clients present low back pain, diffuse buttocks pain, and a history of repetitive loading actively. Although the clinicians in this case did not originally think this injury was another sacral stress fracture, they never ruled out the possibility due to the patient's described pain and pre-existing conditions. The clinicians in this report considered all possible diagnoses before making an assessment. Further research still needs to be performed in order to provide the most effective treatment and outcomes for future patients. Word Count: 59

    The influence of transition metal solutes on dislocation core structure and values of Peierls stress and barrier in tungsten

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    Several transition metals were examined to evaluate their potential for improving the ductility of tungsten. The dislocation core structure and Peierls stress and barrier of 1/21/2 screw dislocations in binary tungsten-transition metal alloys (W1x_{1-x}TMx_{x}) were investigated using first principles electronic structure calculations. The periodic quadrupole approach was applied to model the structure of 1/21/2 dislocation. Alloying with transition metals was modeled using the virtual crystal approximation and the applicability of this approach was assessed by calculating the equilibrium lattice parameter and elastic constants of the tungsten alloys. Reasonable agreement was obtained with experimental data and with results obtained from the conventional supercell approach. Increasing the concentration of a transition metal from the VIIIA group, i.e. the elements in columns headed by Fe, Co and Ni, leads to reduction of the CC^\prime elastic constant and increase of elastic anisotropy A=C44/CC_{44}/C^\prime. Alloying W with a group VIIIA transition metal changes the structure of the dislocation core from symmetric to asymmetric, similar to results obtained for W1x_{1-x}Rex_{x} alloys in the earlier work of Romaner {\it et al} (Phys. Rev. Lett. 104, 195503 (2010))\comments{\cite{WRECORE}}. In addition to a change in the core symmetry, the values of the Peierls stress and barrier are reduced. The latter effect could lead to increased ductility in a tungsten-based alloy\comments{\cite{WRECORE}}. Our results demonstrate that alloying with any of the transition metals from the VIIIA group should have similar effect as alloying with Re.Comment: 12 pages, 8 figures, 3 table

    Measurements of atmospheric layers from the NASA DC-8 and P-3B aircraft during PEM-Tropics A

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    Tropospheric vertical structure was analyzed using in situ measurements of O₃, CO, CH₄, and H₂O taken on board the NASA DC-8 aircraft during three Pacific Exploratory Missions (PEMs): PEM-West A, September-October 1991 in the western Pacific; PEM-West B, February-March 1994 in the western Pacific; and PEM-Tropics A, September-October 1996 in the central and eastern Pacific. PEM-Tropics A added measurements from the NASA P3-B aircraft. We used a new mode-based method to define a background against which to find layers. Using only O₃ and H₂O, we found 472 layers in PEM-Tropics A (0.72 layers per vertical kilometer profiled), 237 layers in PEM-West A (0.54 layers/km), and 158 layers in PEM-West B (0.41 layers/km). Using all constituents, we found 187 layers in PEM-Tropics A (0.43 layers/km), 128 layers in PEM-West A (0.29 layers/km), and 80 layers in PEM-West B (0.21 layers/km). Stratospheric air, sometimes mixed with trapped pollution, was the dominant layer source in all three missions. The larger number of layers per kilometer in PEM-Tropics A was probably due to repeated profiling of several “superlayers” visible in many of the mission lidar and potential voracity profiles. The thickness of the superlayers was of order 1 km, and the horizontal extent was of order 1000 km. We found that layers have an important effect on the thermal structure. An example based on ozonesonde data from Tahiti is shown, where a dry, subsiding layer was stabilized by much greater radiative cooling at the base than at the top. The stabilized layer can trap pollution and force vertical plumes to spread into horizontal layers.United States. National Aeronautics and Space Administration (Grant NAG1-1758)United States. National Aeronautics and Space Administration (Grant NAG1-1901

    Ultrahigh Surface Area Three-Dimensional Porous Graphitic Carbon from Conjugated Polymeric Molecular Framework

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    Porous graphitic carbon is essential for many applications such as energy storage devices, catalysts, and sorbents. However, current graphitic carbons are limited by low conductivity, low surface area, and ineffective pore structure. Here we report a scalable synthesis of porous graphitic carbons using a conjugated polymeric molecular framework as precursor. The multivalent cross-linker and rigid conjugated framework help to maintain micro- and mesoporous structures, while promoting graphitization during carbonization and chemical activation. The above unique design results in a class of highly graphitic carbons at temperature as low as 800 ??C with record-high surface area (4073 m2 g-1), large pore volume (2.26 cm-3), and hierarchical pore architecture. Such carbons simultaneously exhibit electrical conductivity >3 times more than activated carbons, very high electrochemical activity at high mass loading, and high stability, as demonstrated by supercapacitors and lithium-sulfur batteries with excellent performance. Moreover, the synthesis can be readily tuned to make a broad range of graphitic carbons with desired structures and compositions for many applications.clos

    Relativistic Calculation of two-Electron one-Photon and Hypersatellite Transition Energies for 12Z3012\leq Z\leq30 Elements

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    Energies of two-electron one-photon transitions from initial double K-hole states were computed using the Dirac-Fock model. The transition energies of competing processes, the Kα\alpha hypersatellites, were also computed. The results are compared to experiment and to other theoretical calculations.Comment: accepted versio

    A rebellious past : history, theatre and the England riots

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    Alain Badiou has argued that the England riots of 2011, in dialogue with societal upheavals around the world that same year, demonstrated fundamental crises in our governing social, economic and political discourses. Whilst institutional responses to the riots treated them as an aberration, Badiou believes them to be symptomatic of a broader rebirth of ‘history’ – the coalescing of past and present events into a congruent trajectory with powerful implications for the future. Using Badiou’s argument as a starting point, this article considers two theatrical responses to the riots – Nicholas Kent’s premiere of Gillian Slovo’s The Riots at the Tricycle, and Sean Holmes’ revival of Edward Bond’s Saved at the Lyric Hammersmith. By looking at the ways in which the productions sought to historicise the riots, I unpick both their interpretations of these events, and the contributions they were able to make to the urgent and ongoing discussions that the riots have generated.PostprintPeer reviewe

    BDSM Disclosure and Stigma Management: Identifying Opportunities for Sex Education

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    While participation in the activities like bondage, domination, submission/sadism, masochism that fall under the umbrella term BDSM is widespread, stigma surrounding BDSM poses risks to practitioners who wish to disclose their interest. We examined risk factors involved with disclosure to posit how sex education might diffuse stigma and warn of risks. Semi-structured interviews asked 20 adults reporting an interest in BDSM about their disclosure experiences. Most respondents reported their BDSM interests starting before age 15, sometimes creating a phase of anxiety and shame in the absence of reassuring information. As adults, respondents often considered BDSM central to their sexuality, thus disclosure was integral to dating. Disclosure decisions in nondating situations were often complex considerations balancing desire for appropriateness with a desire for connection and honesty. Some respondents wondered whether their interests being found out would jeopardize their jobs. Experiences with stigma varied widely

    Collagen reorganization at the tumor-stromal interface facilitates local invasion

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    BACKGROUND: Stromal-epithelial interactions are of particular significance in breast tissue as misregulation of these interactions can promote tumorigenesis and invasion. Moreover, collagen-dense breast tissue increases the risk of breast carcinoma, although the relationship between collagen density and tumorigenesis is not well understood. As little is known about epithelial-stromal interactions in vivo, it is necessary to visualize the stroma surrounding normal epithelium and mammary tumors in intact tissues to better understand how matrix organization, density, and composition affect tumor formation and progression. METHODS: Epithelial-stromal interactions in normal mammary glands, mammary tumors, and tumor explants in three-dimensional culture were studied with histology, electron microscopy, and nonlinear optical imaging methodologies. Imaging of the tumor-stromal interface in live tumor tissue ex vivo was performed with multiphoton laser-scanning microscopy (MPLSM) to generate multiphoton excitation (MPE) of endogenous fluorophores and second harmonic generation (SHG) to image stromal collagen. RESULTS: We used both laser-scanning multiphoton and second harmonic generation microscopy to determine the organization of specific collagen structures around ducts and tumors in intact, unfixed and unsectioned mammary glands. Local alterations in collagen density were clearly seen, allowing us to obtain three-dimensional information regarding the organization of the mammary stroma, such as radiating collagen fibers that could not have been obtained using classical histological techniques. Moreover, we observed and defined three tumor-associated collagen signatures (TACS) that provide novel markers to locate and characterize tumors. In particular, local cell invasion was found predominantly to be oriented along certain aligned collagen fibers, suggesting that radial alignment of collagen fibers relative to tumors facilitates invasion. Consistent with this observation, primary tumor explants cultured in a randomly organized collagen matrix realigned the collagen fibers, allowing individual tumor cells to migrate out along radially aligned fibers. CONCLUSION: The presentation of these tumor-associated collagen signatures allowed us to identify pre-palpable tumors and see cells at the tumor-stromal boundary invading into the stroma along radially aligned collagen fibers. As such, TACS should provide indications that a tumor is, or could become, invasive, and may serve as part of a strategy to help identify and characterize breast tumors in animal and human tissues

    Sensory ways to indigenous multimodal literacies : Hands and feet tell the story

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    This chapter reports original research that asks the question: What are the ways of knowing, being, and communicating that are valued and practiced in Indigenous communities? Literacy curricula, internationally and nationally, typically do not take into account the multi-sensorial dimensions of non-Western forms of representation that go beyond narrow conceptions of print. For example, literacies are often conceived as drawing on print, visual, spatial, gestural, and audio modes, but the role of haptics and locomotion has typically received little attention. This chapter highlights examples of the multi-sensoriality of Indigenous literacies observed in participatory community research with an Indigenous school. It extends recent theories of sensory studies in the history and cultural anthropology of the senses, applying these principles to literacy education. Sensory literacies is a theoretical perspective that gives priority to the sensorial dimensions of the body and its role in communication in literacy practice, because without a sensing body, we cannot know about or communicate with the world. The data demonstrates how the forgotten role of the hands and feet in dominant theories of communication is central to Indigenous identity and literacies. Written by a white academic with an Indigenous researcher, the chapter problematises the privileging of narrow, logocentric, and Western forms of literacy and its implications for rethinking the role of the whole body in literacy and the literacy curriculum for Indigenous students
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