1,270 research outputs found
Crustal Evolution and Petrogenesis of Silicic Plutonic Rocks within the Oman Ophiolite – Petrological and Geochemical Investigations
What Are The Relationships Among Cumulative Trauma, Posttraumatic Stress Disorder, Sleep Quality, And Perinatal Outcomes In African American Women?
WHAT ARE THE RELATIONSHIPS AMONG CUMULATIVE TRAUMA, POSTTRAUMATIC STRESS DISORDER, SLEEP QUALITY, AND PERINATAL OUTCOMES IN AFRICAN-AMERICAN WOMEN?
NANCY J. HAUFF, MSN, RN
May 2015
Advisor: Judith Fry-McComish, PhD, RN, FAAN, IMH-IV, E
Major: Nursing
Degree: Doctor of Philosophy
Trauma, primarily in the form of intimate partner violence and automobile accidents, accounts for 6-8% of all pregnancy complications. Much less is known about cumulative trauma (CT) exposure especially in African-American women. Women exposed to several types of trauma including childhood abuse, discrimination, or witnessed family violence may develop symptoms of posttraumatic stress or have difficulty sleeping.
The purpose of this study was to examine the relationships among cumulative trauma, posttraumatic stress, sleep, and perinatal outcomes. A sample of 150 essentially healthy African-American women who had given birth were recruited at Hutzel Women\u27s Hospital and St. John Providence Hospital Southfield, and asked to complete the Cumulative Trauma Scale, Community Safety Questionnaire, Conflict Tactics Scale, Clinician-administered PTSD Scale, Pittsburgh Sleep Quality Index, Edinburgh Depression Inventory, and Demographic Data Form. The prenatal and hospital medical records were reviewed for multiple maternal and neonatal outcomes. Regression analysis was used to determine if relationships between the variables exist, and the strength of those relationships. The findings of this study showed: 1) African- American women experience traumatic events. 2) cumulative trauma is associated with PTSD, depression, poor sleep quality, and neonatal outcomes; 3) nursing must go beyond the assessment of intimate partner violence, report active trauma, and record findings in the medical record; and 4) more research is needed to better understand mothers\u27 use of over the counter and other medications to help them sleep. The relevance to maternal child health is that a better understanding of cumulative trauma exposure, PTSD, poor sleep, and the risk for poor perinatal outcomes among African-American women can lead to earlier identification and the development of nursing interventions
Geochronology, geochemistry and Nd, Sr and Pb isotopes of syn-orogenic granodiorites and granites (Damara orogen, Namibia) – arc-related plutonism or melting of mafic crustal sources?
Highlights
• Geochemical data from high-T granodiorites and granites imply lower crustal amphibolite melting.
• New U-Pb zircon ages imply syn-orogenic intrusion
• New Sr-Nd-Pb isotope data imply ancient crustal sources and constrain AFC processes
Abstract:
The Gawib pluton (Damara Belt, Namibia) consists of two main intrusive rock types; magnesian, calc-alkaline, mostly metaluminous hornblende- and titanite-bearing granodiorites and magnesian to ferroan, metaluminous to slightly peraluminous calc-alkaline granites. Uranium-Pb zircon data obtained on the granodiorites gave concordant ages of 548.5 ± 5.6 Ma indicating that the pluton belongs to the early syn-orogenic magmatism in the Damara orogen. Major and trace element variations indicate that fractional crystallization was the major rock-forming mechanism for the granodiorites. In the absence of high-precision geochronological data, the granites may represent more advanced fractionation products of the granodiorites although distinct Ba-Sr-Rb relationships preclude a direct derivation of the granites from the exposed granodiorites. If the granites originated by extensive fractional crystallization from similar granodiorites, they can only be derived from high-Ba, high-Sr, low-Rb granodiorites. Crustal contamination was also important in the petrogenesis of both rock types (granodiorites: ε Nd(init.): -7 to -13; 87Sr/86Sr(init.): 0.708-0.713; granites: ε Nd(init): -14 to -18; 87Sr/86Sr(init.): 0.712-0.726). In contrast to the granodiorites, the granites show more radiogenic 87Sr/86Sr ratios and less radiogenic ε Nd values indicating different contaminants for both rock types. ε Nd vs. MgO relationships imply some genetic link to isotopically unevolved quartz diorites similar to those observed at the Palmental complex. This pluton, however, is located c. 80 km NE from the Gawib pluton and probably cannot be viewed as the direct source of the Gawib granodiorites. If such a relationship is allowed, the granodiorites must be viewed as hybrid rocks containing a juvenile component because they were derived from unevolved quartz diorites by fractional crystallization. In addition, AFC processe have also played a role implying that the granodiorites contain also a reprocessed crustal component. Alternatively, comparison with experimentally derived melts imply that the granodiorites are generated by dehydration melting of a mafic, amphibole-bearing lower crustal source. Chemical parameters of the granodiorites compared to experimental results indicate high temperatures of c. 1040 °C. Zirconium saturation temperatures obtained on the most primitive samples gave c. 830 °C whereas apatite saturation temperatures obtained on the same samples give temperatures of c. 960-980 °C; the latter seems to be a more reliable temperature estimate. Interpretation of geochemical and isotope data from the complex suggest that the early synorogenic Pan-African igneous activity in this part of the Damara Belt was a high-temperature intra-crustal event. In contrast to igneous processes along active continental margins that produce also intermediate plutons with calc-alkaline affinities, this igneous event was not a major crust-forming episode and the granodiorites represent mostly reprocessed crustal material
A Textured Silicon Calorimetric Light Detector
We apply the standard photovoltaic technique of texturing to reduce the
reflectivity of silicon cryogenic calorimetric light detectors. In the case of
photons with random incidence angles, absorption is compatible with the
increase in surface area. For the geometrically thin detectors studied, energy
resolution from athermal phonons, dominated by position dependence, is
proportional to the surface-to-volume ratio. With the CaWO4 scintillating
crystal used as light source, the time constants of the calorimeter should be
adapted to the relatively slow light-emission times.Comment: Submitted to Journal of Applied Physic
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