10,059 research outputs found

    Electromagnetic interference aspects of integrating a UHF/VHF receiver onboard Mariner 5

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    Electromagnetic interference assessment in integration of Mariner 5 UHF/VHF receive

    Development of a KSC test and flight engineering oriented computer language, Phase 1

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    Ten, primarily test oriented, computer languages reviewed during the phase 1 study effort are described. Fifty characteristics of ATOLL, ATLAS, and CLASP are compared. Unique characteristics of the other languages, including deficiencies, problems, safeguards, and checking provisions are identified. Programming aids related to these languages are reported, and the conclusions resulting from this phase of the study are discussed. A glossary and bibliography are included. For the reports on phase 2 of the study, see N71-35027 and N71-35029

    Positron Tunnelling through the Coulomb Barrier of Superheavy Nuclei

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    We study beams of medium-energy electrons and positrons which obey the Dirac equation and scatter from nuclei with Z>100.Z > 100. At small distances the potential is modelled to be that of a charged sphere. A large peak is found in the probability of positron penetration to the origin for Z≈184.Z \approx 184. This may be understood as an example of Klein tunnelling through the Coulomb barrier: it is the analogue of the Klein Paradox for the Coulomb potential.Comment: 3 figures, to be published in Physics Letters

    Factors That Have Influenced Infant and Maternal Mortality in Ghana: A Review

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    Objectives: This paper aims to explore the factors that influence maternal and infant mortality rates in Ghana. These include: cultural practices, demographics, quality and type of healthcare, affordability of insurance, traditional midwifery, treatment of women, the environment, and transportation. Methods: The study included a literature review of health service outcomes annual reports, and observational visits to healthcare facilities in Ghana that was done from March 6th-March 17th 2017. Results: Ghana had a significant reduction of both maternal and infant mortality rates from 2005 to 2015. In 2005, Ghana had a maternal mortality rate of 376 maternal deaths per 100,000 live births, and in 2005 the infant mortality rate was 56.8 deaths per 1,000 live births. In 2015, the maternal mortality rate was 319 maternal deaths per 100,000 live births, a reduction by 57 deaths or by 15.16 percent. In 2015, the infant mortality rate was 42.8 deaths per 1,000 live births, a reduction by 14 deaths or by 24.65 percent (Maternal Mortality, n.d.; Mortality Rate, Infant, 2016). Ghana Demographic Health Survey 2014 reveals an increase in healthcare utilization with more women obtaining prenatal care from licensed healthcare providers and delivering in healthcare institutions (Ghana Demographic Health Survey, 2015). Between 2003 and 2014, children attained higher vaccination coverage and had a reduction in diarrheal diseases, malnutrition, and upper respiratory tract infections which are major causes of infant mortality (Ghana Demographic Health Survey, 2015). There was an increase in home follow-up visits for prenatal and postpartum mothers. Conclusion: The increase in the use of healthcare services, along with the supervision of community healthcare by licensed professionals, has affected mortality rates in both women and children in Ghana. Community involvement for healthcare mobilization appears to be the linchpin for success in reduction of maternal and infant mortality. Understanding and using culturally appropriate health education messages continues to be the most important focus that would help further reduce mortality. Use of affordable and accessible resources for prenatal, delivery, and postpartum care would encourage more women to give birth in healthcare facilities

    Strategic Neighboring and Beloved Community Development in West Atlanta Neighborhoods

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    This study investigates the phenomenon of faith-motivated actors in blighted inner-city neighborhoods on the west side of Atlanta, Georgia. In merging community development literature with a framework of place, this research explores the role of faith in neighborhood transformation efforts. In particular, it examines the motivations and values of these actors that shape how they conceptualize their neighborhoods and in turn how these values are then inscribed into place. Fewer than 40 strategic neighbors are known to be active in Atlanta’s west side; of these 32 participated in the research through in-depth interviews, surveys, diaries and other qualitative research methods. Through this extensive qualitative investigation, this thesis explores the middle-class identity struggles experienced by participants as they reconfigure the social and material spaces of their neighborhoods as they live out their faith

    AGE- AND SEX-DEPENDENT ALTERATIONS IN PRIMARY SOMATOSENSORY NEURONAL CALCIUM NETWORK DYNAMICS DURING LOCOMOTION

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    Over the past 30 years, the calcium (Ca2+) hypothesis of brain aging has provided clear evidence that hippocampal neuronal Ca2+ dysregulation is a key biomarker of aging. Indeed, age-dependent Ca2+-mediated changes in intrinsic excitability, synaptic plasticity, and activity have helped identify some of the mechanisms engaged in memory and cognitive decline. However, much of this work has been done at the single-cell level, mostly in slice preparations, and in restricted structures of the brain. Recently, our lab identified age- and Ca2+-related neuronal network dysregulation in the cortex of the anesthetized animal. Still, investigations in the awake animal are needed to test the generalizability of the Ca2+ hypothesis of brain aging and dementia. Here, we used in vigilo two-photon (2P) imaging in ambulating mice, to image GCaMP8f in the primary somatosensory cortex (S1), during ambulation and at rest. In order to investigate aging- and sex- related changes in the neuronal Ca2+ network, a continuous wavelet transform (CWT) analysis was developed (MATLAB) to extract measures of network communication while also addressing pair-wise correlations at single-cell resolution. Following imaging, gait behavior was characterized to test for changes in locomotor stability. During ambulation and compared to rest, in both young (4 months) and aged mice (22 months), an increase in connectivity and synchronicity was noted. An age-dependent increase in network synchronicity was seen in ambulating aged males only. Additionally, females displayed a greater number of active neurons, area-under-curve, and neuronal activity compared to males, particularly during ambulation. These results suggest S1 Ca2+ dynamics and network synchronicity are likely contributors of locomotor stability. We believe this work raises awareness of central elements at play in S1 where neuronal Ca2+ network dysregulation is seen with aging, perhaps highlighting potential therapeutic targets that may help offset age-dependent increases in falls

    Distribution and abundance of zoobenthos in channel springbrook and hyporheic habitats of an alluvial floodplain

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