Studies on megagametogenesis in Clematis (Ranunculaceae)

Call number: LD2668 .T4 1966 F532Master of Scienc

Conductive Sphere on a Charged Conductive Plane

Statement of the Problem: If a conductive sphere is placed in contact with a semi-infinite, conductive plane, the configuration constitutes a three-dimensional equipotential surface. Assuming an isolated plane to be electrically charged to a known surface charge density (σ°) originally, it is desired to determine the effect produced by placing a sphere on the plane. Specifically, the purpose of this investigation is to determine the force exerted on the sphere normal to the plane, the total charge acquired by the sphere and the perturbation in the electrical field due to its presence on the plane

Distribution and Ecology of the Littoral Foraminifera of Timbalier Bay, Louisiana

Paper by John Robert Inabinet and A. Geoffrey Fis

Mitigation of Radiation Induced Pulmonary Vascular Injury by Delayed Treatment with Captopril

Background and Objective: A single dose of 10 Gy radiation to the thorax of rats results in decreased total lung angiotensin-converting enzyme (ACE) activity, pulmonary artery distensibility and distal vascular density while increasing pulmonary vascular resistance (PVR) at 2 months post-exposure. In this study, we evaluate the potential of a renin-angiotensin system (RAS) modulator, the ACE inhibitor captopril, to mitigate this pulmonary vascular damage. Methods: Rats exposed to 10 Gy thorax only irradiation and age-matched controls were studied 2 months after exposure, during the development of radiation pneumonitis. Rats were treated, either immediately or 2 weeks after radiation exposure, with two doses of the ACE inhibitor, captopril, dissolved in their drinking water. To determine pulmonary vascular responses, we measured pulmonary haemodynamics, lung ACE activity, pulmonary arterial distensibility and peripheral vessel density. Results: Captopril, given at a vasoactive, but not a lower dose, mitigated radiation-induced pulmonary vascular injury. More importantly, these beneficial effects were observed even if drug therapy was delayed for up to 2 weeks after exposure. Conclusions: Captopril resulted in a reduction in pulmonary vascular injury that supports its use as a radiomitigator after an unexpected radiological event such as a nuclear accident

Mapping Synaptic Pathology within Cerebral Cortical Circuits in Subjects with Schizophrenia

Converging lines of evidence indicate that schizophrenia is characterized by impairments of synaptic machinery within cerebral cortical circuits. Efforts to localize these alterations in brain tissue from subjects with schizophrenia have frequently been limited to the quantification of structures that are non-selectively identified (e.g., dendritic spines labeled in Golgi preparations, axon boutons labeled with synaptophysin), or to quantification of proteins using methods unable to resolve relevant cellular compartments. Multiple label fluorescence confocal microscopy represents a means to circumvent many of these limitations, by concurrently extracting information regarding the number, morphology, and relative protein content of synaptic structures. An important adaptation required for studies of human disease is coupling this approach to stereologic methods for systematic random sampling of relevant brain regions. In this review article we consider the application of multiple label fluorescence confocal microscopy to the mapping of synaptic alterations in subjects with schizophrenia and describe the application of a novel, readily automated, iterative intensity/morphological segmentation algorithm for the extraction of information regarding synaptic structure number, size, and relative protein level from tissue sections obtained using unbiased stereological principles of sampling. In this context, we provide examples of the examination of pre- and post-synaptic structures within excitatory and inhibitory circuits of the cerebral cortex

Feasibility Study for Machine Processing Croakers into Fillets and for Forming the Fillets into Larger Portions

The purpose of this project was to discover ways to economically process croakers into forms the market would more readily accept. Several manufacturing companies\u27 processing machines were investigated. Two manufacturing companies\u27 processing machines were brought to Hampton for testing. No company makes machinery specifically designed to process croaker. Small croaker fillets were also bound into larger fillets successfully. Processing machines were identified that will work and were purchased. The machinery is currently being successfully used to produce croaker fillets for both the frozen and fresh market. However, the machines are still being modified to improve the quality of the cut. While croaker fillets were successfully bound into larger pieces, further work needs to be done before that process is commercially viable

Fatigue and Fracture Library for the Inspection, Evaluation, and Repair of Vehicular Steel Bridges

Of all the limit states that affect the performance of steel bridges, fatigue and fracture are often misunderstood when it comes to design, inspection, and repair/retrofit. Although there is a wealth of research and case studies of failures related to cracking in the literature, few civil engineering programs offer any courses that spend more than a lecture or two on these topics. There are even fewer courses or credible reference manuals available on the repair and retrofit of steel bridges that are in service. Hence, owners often are left to develop their own strategies when it comes to repair or retrofit. Unfortunately, in some cases, the repair or retrofit selected has been observed to make the condition worse due to a lack of understanding of the problem, lack of available reference materials, and/or lack of experienced personnel. The intent of this document is to provide engineers and inspectors with technical guidance regarding evaluation, repair, and retrofit procedures for both common as well as nonstandard, noncompliant, or failed details commonly encountered on steel bridge structures