4,060 research outputs found

    Neutron detector simultaneously measures fluence and dose equivalent

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    Neutron detector acts as both an area monitoring instrument and a criticality dosimeter by simultaneously measuring dose equivalent and fluence. The fluence is determined by activation of six foils one inch below the surface of the moderator. Dose equivalent is determined from activation of three interlocked foils at the center of the moderator

    Using Wii Technology and Experiential Learning to Teach Newtonian Mechanics to Rural Middle School Students

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    This study looked at the effects of an experiential learning activity using the accelerometer in the Wii Remote to teach basic concepts of Newtonian mechanics, e.g., acceleration, to middle school students in a rural school district. A major prerequisite for students at the mid-level in biosystems engineering programs is that they have a good knowledge of basic science, including physics. Education in these concepts must begin before college, such as at the middle school level. Improvements in science education are vitally necessary to achieve essential learning outcomes for middle school students in the U.S. and to prepare these students for college and STEM careers. The experiential learning activity evaluated in this study used hands-on experiments involving Wii Remotes in conjunction with a classroom lesson to teach basic concepts of Newtonian mechanics: acceleration, gravity, force, velocity, friction, speed, and motion. This activity used readily available equipment and was integrated into the classroom curriculum so that it has been possible to continue the activity every year without further support from the program that sponsored this study. The specific objective of this study was to evaluate the efficacy of this experiential learning activity with regard to learning outcomes and interest generated in science and engineering. Ninety-two percent (92%) of the students improved their knowledge from pre-test to post-test during the activity. When the students were surveyed about the activity, the kinesthetic/hands-on aspects of the project were the parts they liked most. Fifty-four percent (54%) of the students also indicated that the activity made them more interested in science and engineering. The positive outcomes from the activity combined with the readily available equipment make similar activities an excellent option for biosystems and agricultural engineering departments looking for outreach opportunities at the middle school level. This study showed that experiential learning, in middle school science classes, is significant in increasing students‘ knowledge of acceleration and interest in science and engineering

    Apps —An Innovative Way to Share Extension Knowledge

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    Extension professionals across the country are continuously seeking innovative ways to reach clientele and to disseminate timely, educational information. A new avenue to reach clientele includes the use of smartphone apps. The Machinery Sizing app, which was developed to ease the estimation of tractor horsepower to implement sizing for Extension clientele anytime, anywhere, is explained as a key example for Extension professionals to utilize apps in disseminating information to clientele. There are many benefits to using apps, including information availability wherever Internet service is available on the smartphone, ease of computations of equations, and automatic updates being sent to users

    Utilization of Birefringent Fiber as Sensor of Temperature Field Disturbance

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    The paper deals with utilization of induced birefringence sensitivity to temperature field in birefringent optical fibers. The propagating optical wave and optical fibers are described by means of coherency and Jones matrices, which are decomposed into unitary matrix and spin matrices. The development of polarization caused by temperature field is interpreted on the Poincare sphere by means of MATLABÂź environment. The temperature sensitivity of Panda and bow-tie fiber has been measured for circular polarization excitation. Curves of intensity fluctuation caused by the temperature dependence are presented

    Juvenile Myelomonocytic Leukemia: Molecular Pathogenesis Informs Current Approaches to Therapy and Hematopoietic Cell Transplantation

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    Juvenile myelomonocytic leukemia (JMML) is a rare childhood leukemia that has historically been very difficult to confidently diagnose and treat. The majority of patients ultimately require allogeneic hematopoietic cell transplantation (HCT) for cure. Recent advances in the understanding of the pathogenesis of the disease now permit over 90% of patients to be molecularly characterized. Pre-HCT management of patients with JMML is currently symptom-driven. However, evaluation of potential high-risk clinical and molecular features will determine which patients could benefit from pre-HCT chemotherapy and/or local control of splenic disease. Furthermore, new techniques to quantify minimal residual disease burden will determine whether pre-HCT response to chemotherapy is beneficial for long-term disease-free survival. The optimal approach to HCT for JMML is unclear, with high relapse rates regardless of conditioning intensity. An ongoing clinical trial in the Children’s Oncology Group will test if less toxic approaches can be equally effective, thereby shifting the focus to post-HCT immunomanipulation strategies to achieve long-term disease control. Finally, our unraveling of the molecular basis of JMML is beginning to identify possible targets for selective therapeutic interventions, either pre- or post-HCT, an approach which may ultimately provide the best opportunity to improve outcomes for this aggressive disease

    Lipid Body–Phagosome Interaction in Macrophages during Infectious Diseases: Host Defense or Pathogen Survival Strategy?

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    Phagocytosis of invading microorganisms by specialized cells such as macrophages and neutrophils is a key component of the innate immune response. These cells capture and engulf pathogens and subsequently destroy them in intracellular vacuoles—the phagosomes. Pathogen phagocytosis and progression and maturation of pathogen-containing phagosomes, a crucial event to acquire microbicidal features, occurs in parallel with accentuated formation of lipid-rich organelles, termed lipid bodies (LBs), or lipid droplets. Experimental and clinical infections with different pathogens such as bacteria, parasites, and viruses induce LB accumulation in cells from the immune system. Within these cells, LBs synthesize and store inflammatory mediators and are considered structural markers of inflammation. In addition to LB accumulation, interaction of these organelles with pathogen-containing phagosomes has increasingly been recognized in response to infections and may have implications in the outcome or survival of the microorganism within host cells. In this review, we summarize our current knowledge on the LB-phagosome interaction within cells from the immune system, with emphasis on macrophages, and discuss the functional meaning of this event during infectious diseases

    Detection of testosterone administration based on the carbon isotope ratio profiling of endogenous steroids: international reference populations of professional soccer players

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    BACKGROUND AND OBJECTIVES: The determination of the carbon isotope ratio in androgen metabolites has been previously shown to be a reliable, direct method to detect testosterone misuse in the context of antidoping testing. Here, the variability in the 13C/12C ratios in urinary steroids in a widely heterogeneous cohort of professional soccer players residing in different countries (Argentina, Italy, Japan, South Africa, Switzerland and Uganda) is examined. METHODS: Carbon isotope ratios of selected androgens in urine specimens were determined using gas chromatography/combustion/isotope ratio mass spectrometry (GC-C-IRMS). RESULTS: Urinary steroids in Italian and Swiss populations were found to be enriched in 13C relative to other groups, reflecting higher consumption of C3 plants in these two countries. Importantly, detection criteria based on the difference in the carbon isotope ratio of androsterone and pregnanediol for each population were found to be well below the established threshold value for positive cases. CONCLUSIONS: The results obtained with the tested diet groups highlight the importance of adapting the criteria if one wishes to increase the sensitivity of exogenous testosterone detection. In addition, confirmatory tests might be rendered more efficient by combining isotope ratio mass spectrometry with refined interpretation criteria for positivity and subject-based profiling of steroids
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