Charge exchange lifetimes for ions in the magnetosphere

Latest and best measurements of physical quantities involved in complete calculation of the charge exchange lifetime of mirroring magnetospheric ions are coalesced and summarized. It is critical that the charge exchange lifetimes for ions be known as accurately as possible in order to apply the charge exchange mechanism to ion phenomena within the earth's magnetosphere

Dependence of the charge exchange lifetimes on mirror latitude

The dependence of the charge exchange lifetimes on the mirror latitude for ions mirroring off the geomagnetic equator was re-computed using the improved hydrogen distribution models. The Chamberlain model was used to define the spatial distribution of the neutral hydrogen environment through which the ring current ions traverse. The resultant dependence of the charge exchange lifetime on mirror latitude is best fitted by the approximation that contains the charge exchange lifetime for equatorial particles

Fibroadenoma in women in Ghana

BACKGROUND:Fibroadenoma is the commonest benign tumor of female breast. It is particularly common in young women in Africa. METHODS: This paper describes the clinicopathologic features of fibroadenoma of breast in African women from central Ghana and compares them to the data from African-American women. RESULTS: Fibroadenomas constituted 47.7% of all palpable breast masses. The median age of women was 22 years (range 14-49). Almost a third of the cases occurred in teenager. The mean size of masses was 3.8 cm (range 1-9 cm), with 22.5% showing larger sizes. A total of 16.1% had multiple and/or bilateral lesions. CONCLUSION: Women from Central Ghana tend to have proportionately more fibroadenomas and larger (>5 cm) variants compared to published data from African-American women, however, the average age, size, multifocality and bilaterality do not differ significantly between these two groups of women

Dying Tt Save Your Colon? Changing the Way We Look at Ulcerative Colitis

Treatment options for mesalamine-refractory ulcerative colitis (UC) include chronic immunosuppressive medications or colectomy surgery. Current treatment paradigms presume the patients\u27 foremost desire is to avoid surgery and therefore view surgery as a consequence of medication failure. However, immunosuppressive therapy may not be ideal for all patients due to unclear durable efficacy and potential lethal serious adverse events (SAEs). We sought to quantify UC patients\u27 risk tolerance of chronic immunosuppression to avoid colectomy. We first conducted a meta-analysis of all-cause and cause-specific mortality in both Crohn\u27s disease (CD) and UC, and examined the effect of study design on this outcome. We found elevated all-cause and cause-specific mortality in both UC and CD including colorectal-, pulmonary- and non-alcoholic liver disease-related relative mortality. We further found little evidence that study design impacted all-cause relative mortality summary estimates. We next conducted a study examining the reliability of the 6-Point Mayo score, a simple two-item non-invasive non-physician driven index, for measuring UC disease activity. We found the 6-Point Mayo to strongly correlate with more extensive disease assessment tools, with a similar sensitivity, specificity and ROC area under the curve for patient-defined clinical remission. With these insights, we conducted a discrete choice experiment to quantify the UC patients\u27 mean maximum acceptable risk for life-threatening SAEs associated with immunosuppressant therapy to avoid colectomy surgery with various outcomes. We found that UC patient tolerance for medical and surgical risks do not conform to conventional preference-elicitation methodology assumptions. UC patients were willing to accept very high levels of fatal SAEs to avoid an ostomy. However, if a durable medication-induced remission could not be achieved, patients were equally satisfied with J-pouch surgery. Several important clinical phenotypes impacted patient risk tolerances. This is the first empirical demonstration that UC patients view a well-functioning J-pouch as equivalent to mild clinical disease. It further demonstrates that patients value medication efficacy and suggests that clinical remission, rather than response, be the preferred outcome for therapy trials and treatment algorithms. Our findings underline the need for rigorous methodologies to accurately measure patient-preferences; and suggest potential avenues to enhance UC patient autonomy and facilitate shared decision-making

Heat Capacity Mapping Radiometer (HCMR) data processing algorithm, calibration, and flight performance evaluation

The rationale and procedures used in the radiometric calibration and correction of Heat Capacity Mapping Mission (HCMM) data are presented. Instrument-level testing and calibration of the Heat Capacity Mapping Radiometer (HCMR) were performed by the sensor contractor ITT Aerospace/Optical Division. The principal results are included. From the instrumental characteristics and calibration data obtained during ITT acceptance tests, an algorithm for post-launch processing was developed. Integrated spacecraft-level sensor calibration was performed at Goddard Space Flight Center (GSFC) approximately two months before launch. This calibration provided an opportunity to validate the data calibration algorithm. Instrumental parameters and results of the validation are presented and the performances of the instrument and the data system after launch are examined with respect to the radiometric results. Anomalies and their consequences are discussed. Flight data indicates a loss in sensor sensitivity with time. The loss was shown to be recoverable by an outgassing procedure performed approximately 65 days after the infrared channel was turned on. It is planned to repeat this procedure periodically

Inference of the ring current ion composition by means of charge exchange decay

The analysis of the measured ion fluxes during the several day storm recovery period and the assumption that beside hydrogen other ions were present and that the decays were exponential in nature, it was possible to establish three separate lifetimes for the ions. These fitted decay lifetimes are in excellent agreement with the expected charge exchange decay lifetimes for H(+), O(+), and He(+) in the energy and L-value range of the data. This inference technique, thus, establishes the presence of measurable and appreciable quantities of oxygen and helium ions as well as protons in the storm-time ring current. Indications that He(+) may also be present under these same conditions were found

Motions of charged particles in the Magnetosphere under the influence of a time-varying large scale convection electric field

The motions of charged particles under the influence of the geomagnetic and electric fields were quite complex in the region of the inner magnetosphere. The Volland-Stern type large scale convection electric field was used successfully to predict both the plasmapause location and particle enhancements determined from Explorer 45 measurements. A time dependence in this electric field was introduced based on the variation in Kp for actual magnetic storm conditions. The particle trajectories were computed as they change in this time-varying electric field. Several storm fronts of particles of different magnetic moments were allowed to be injected into the inner magnetosphere from L = 10 in the equatorial plane. The motions of these fronts are presented in a movie format

Optical photoreceptors for CMOS neural circuitry.

The work described in this thesis relates to the design of photoreceptors fabricated in Northern Telecom\u27s 3$\mu$ CMOS process. The photoreceptor consists of a vertical BJT whose output current is fed to four diode connected MOSFETs. Results of the experiments used to characterize the device both optically and electronically are given. Shortcomings of the device are identified and a modified photoreceptive device has been designed. These photoreceptive devices will be used to provide optical inputs to a neural network. By using optical connections to provide inputs to the chip, data can be sent directly to individual locations on the chip from above. This approach may eventually be used to solve the problems of an analog storage device and of pin-limitations usually associated with the VLSI implementation of neural networks. An architecture for making optimal use of the photoreceptors characteristics is given. This current mode architecture uses the current from the photoreceptor as the input to the network as well as the weights. Source: Masters Abstracts International, Volume: 31-03, page: 1315. Thesis (M.A.Sc.)--University of Windsor (Canada), 1991

Application of sensory-analytical techniques to odor analysis : a distillery case study.

Dept. of Chemistry and Biochemistry. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1978 .B498. Source: Masters Abstracts International, Volume: 40-07, page: . Thesis (M.A.Sc.)--University of Windsor (Canada), 1978