Temperature dependent carrier lifetime studies of Mo in crystalline silicon

The capture cross sections of both electronsσn and holes σp were determined for interstitialmolybdenum in crystalline silicon over the temperature range of −110 to 150 °C. Carrier lifetimemeasurements were performed on molybdenum-contaminated silicon using a temperature controlled photoconductance instrument. Injection dependent lifetime spectroscopy was applied at each temperature to calculate σp and σn. This analysis involved a novel approach that independently determined the capture cross sections at each temperature assuming a known defect density and thermal velocity. Since the energy state is in the lower half of the bandgap, the determination of σp is unaffected by the defect energy at all temperatures, and σp is found to decrease with temperature in a fashion consistent with excitonic Auger capture. At temperatures below 0 °C, the determination of σn is also unaffected by the defect energy due to the suppression of thermal emission, and σn decreases with temperature as well. It is shown that a projection of σn to higher temperature suggests the defect has an energy of 0.375 eV above the valance band edge of silicon.D.M. likes to thank the Australian Research Council for fellowship and G.C. likes to thank “CrystalClear Integrated Project” Contract No. SES6-CT_2003-502583 funded by the European Commission

The natural resources of Carpinteria Marsh: their status and future

The purpose of this report is: 1) to document the natural resources of Carpinteria Marsh, 2) outline the uses those resources receive, 3) enumerate the problems and conflicts of use that affect those resources, and 4) recommend measures that will protect and enhance the marsh and its resources. It is intended as a guide for citizens, planners and administrators of all private and public entities interested in the status and future of the marsh. This report has been prepared under contract to and fully funded by the Office of Biological Services of the U.S. Fish and Wildlife Service. The goals and purpose of this federal office are to review the impact on fish and wildlife resources of land, mineral and water development practices, such as offshore oil and gas exploration, development and production; construction of inshore pipeline canals and refineries; power plant construction/operation and urban development. This report, and five other southern California reports, covering Agua Hedionda (San Diego County), Anaheim Bay-Huntington Harbor (Orange County), Mugu Lagoon (Ventura County), the Northern Santa Barbara County Coastal Wetlands and the Nipomo Dunes and Wetlands (San Luis Obispo County), are scheduled to be part of the Department's "Coastal Wetland Series" that includes reports on the natural resources of Upper Newport Bay (Orange County), Goleta Slough (Santa Barbara county), Bolinas Lagoon (Marin County), Elkhorn Slough (Monterey County), San Diego Bay and Los Penasquitos Lagoon (San Diego County), Morro Bay (San Luis Obispo County), Humboldt Bay and the Eel River Delta (Humboldt County), Lake Earl and the Smith River Delta (Del Norte County) and Bodega Harbor (Sonoma County). (103pp.

Generalized procedure to determine the dependence of steady-state photoconductance lifetime on the occupation of multiple defects

We present a procedure to determine the dependence of photoconductance lifetime on the occupation of multiple defects. The procedure requires numerical iteration, making it more cumbersome than the analytical equations available for single-defect and simplified two-defect cases, but enabling the following features: (i) it accounts for the defect concentration when calculating the equilibrium carrier concentrations, (ii) it permits recombination through any number of defects, (iii) it calculates the occupation fraction of all defects at any injection, and (iv) it promotes a good understanding of the role of defect occupation in photoconductance measurements. The utility of the numerical procedure is demonstrated on an experimental sample containing multiple defects. The dependence of the sample’s photoconductance on carrier concentration and temperature can be qualitatively described by the generalized procedure but not by either analytical model. The example also demonstrates that the influence of defect occupation on photoconductance lifetime measurements is mitigated at elevated temperatures—a conclusion of particular worth to the study of multicrystalline silicon.This work was funded by an Australian Research Council Linkage Grant between the Australian National University, SierraTherm Production Furnaces, and SunPower Corporation. D.M. is supported by an Australian Research Council fellowship

In Situ Digestibility of Residue Parts of Corn Planted in Different Populations and Row Widths

Plant density can be changed by altering row width and/or number of plants within a row. The use of narrower rows at seeding may increase yield and reduce plant-toplant competition. Corn seeds were planted at 2 row widths (15 and 30- inch rows) and 3 plant populations (25,200, 35,000 and 54,000 seeds / acre). Samples of corn residue were collected 4 dates (October 8, October 24, November 5 and November 19) postharvest and separated into cob, stem, leaf and husk to determine changes in quality over time. Th e greatest plant population increased the NDF content and NDF digestibility of husk, NDF and true digestibilities of cob, NDF content of stem, and decreased the true digestibility of the stem. The NDF content of the leaves and stem increased over time while the NDF and true digestibilities of cob decreased over time. Row width did not affect the corn residue. Planting densities and management strategies can affect the digestibility of leaf and husk and may impact residue quality

A case control study of environmental and occupational exposures associated with methicillin resistant Staphylococcus aureus nasal carriage in patients admitted to a rural tertiary care hospital in a high density swine region

Background: Distinct strains of methicillin resistant Staphylococcus aureus (MRSA) have been identified on livestock and livestock workers. Industrial food animal production may be an important environmental reservoir for human carriage of these pathogenic bacteria. The objective of this study was to investigate environmental and occupational exposures associated with nasal carriage of MRSA in patients hospitalized at Vidant Medical Center, a tertiary hospital serving a region with intensive livestock production in eastern North Carolina. Methods: MRSA nasal carriage was identified via nasal swabs collected within 24 hours of hospital admission. MRSA carriers (cases) were gender and age matched to non-carriers (controls). Participants were interviewed about recent environmental and occupational exposures. Home addresses were geocoded and publicly available data were used to estimate the density of swine in residential census block groups of residence. Conditional logistic regression models were used to derive odds ratio (OR) estimates and 95% confidence intervals (CI). Presence of the scn gene in MRSA isolates was assessed. In addition, multi locus sequence typing (MLST) of the MRSA isolates was performed, and the Diversilab® system was used to match the isolates to USA pulsed field gel electrophoresis types. Results: From July - December 2011, 117 cases and 119 controls were enrolled. A higher proportion of controls than cases were current workforce members (41.2% vs. 31.6%) Cases had a higher odds of living in census block groups with medium densities of swine (OR: 4.76, 95% CI: 1.36-16.69) and of reporting the ability to smell odor from a farm with animals when they were home (OR: 1.51, 95% CI: 0.80-2.86). Of 49 culture positive MRSA isolates, all were scn positive. Twenty-two isolates belonged to clonal complex 5. Conclusions: Absence of livestock workers in this study precluded evaluation of occupational exposures. Higher odds of MRSA in medium swine density areas could reflect environmental exposure to swine or poultry

Body image concerns in patients with head and neck cancer: a longitudinal study

Objective: Head and neck cancer (HNC) treatments are known to significantly affect functionality and appearance, leading to an increased risk for body image disturbances. Yet, few longitudinal studies exist to examine body image in these patients. Based on a conceptual model, the current study aimed to determine, in patients newly diagnosed with HNC: (1) the prevalence, level, and course of body image concerns; (2) correlates of upon cancer diagnosis (pre-treatment) body image concerns; (3) predictors of immediate post-treatment body image concerns; and (4) association between body image concerns and levels of anxiety, depression, suicidal ideation, support (i.e., satisfaction with support from physician, social/family wellbeing, and unmet support needs), and alcohol and drug misuse. Methods: Two hundred and twenty-three (participation rate = 72%), newly diagnosed with a primary HNCwereassessedusing structured clinical interviews and psychometric measures at three, and 6 months after diagnosis. Primary outcome was 3-month, as it was most salient to body image disturbance. Multiple linear regression analyses were conducted on the potential body image predictors, based on the model. Results: Sixty-eight percent of patients with HNC (n = 148 of 218) presented some level of body image concerns. Body image concerns at baseline (i.e., upon cancer diagnosis, pre-treatment) and post-treatment were significantly related and significantly increased from pre- to post-treatment. Immediately post-treatment (i.e., at 3 month follow-up), 89% (n = 132 of 148) presented some level of body image concerns. Correlates of body image concerns in patients with HNC at baseline included: physical symptom burden, difficulties with communication and eating, coping with the cancer diagnosis using denial, suicidal ideation, and having had a past anxiety diagnosis. When controlling for sociodemographic and medical variables, body image concerns in patients with HNCin the immediate post-treatment were predicted by: baseline body image, physical symptom burden, and neuroticism

Biopsychosocial Markers of Body Image Concerns in Patients with Head and Neck Cancer: A Prospective Longitudinal Study

Background: Patients and survivors of head and neck cancer (HNC) are at a high risk of developing body image concerns. Despite the prevalence of body image concerns in patients with HNC, there is a lack of longitudinal research exploring the wide array of its associated determinants. The current longitudinal study examined the determinants and longitudinal course of body image dissatisfaction in patients with HNC. Methods: Patients participated in Structured Clinical Interviews and self-administered questionnaires at four time-points: (T1) upon cancer diagnosis, (T2) at 3 months post-diagnosis, (T3) at 6 months post-diagnosis, and (T4) at 12 months post-diagnosis. They also underwent a disfigurement rating on an objective scale. Results: Two hundred and twenty-four patients participated in our study. Fourteen percent to twenty-eight percent of patients reported at least moderate body image concerns across time points, with the lowest rates at baseline and the highest at 3 months (T1). It was found that patients more predisposed to developing higher levels of body image concerns presented physical markers (i.e., advanced cancer stage, lower physical functioning, higher disfigurement), psychosocial markers (i.e., higher depression, higher anxiety, and higher levels of coping with denial), and health disparities (i.e., younger age, female sex, French language, and marital status, with divorced and widowers most affected). Conclusions: The findings of this study highlight the multifaceted nature of body image concerns in patients with HNC and its biopsychosocial determinants. Clinicians should pay specific attention to these biopsychosocial markers in their clinics to predict high levels of body image concerns and tailor communication/refer for support accordingly

Medical and Household Characteristics Associated with Methicillin Resistant Staphylococcus aureus Nasal Carriage among Patients Admitted to a Rural Tertiary Care Hospital

BackgroundMethicillin resistant Staphylococcus aureus (MRSA) poses a threat to patient safety and public health. Understanding how MRSA is acquired is important for prevention efforts. This study investigates risk factors for MRSA nasal carriage among patients at an eastern North Carolina hospital in 2011.MethodsUsing a case-control design, hospitalized patients ages 18 – 65 years were enrolled between July 25, 2011 and December 15, 2011 at Vidant Medical Center, a tertiary care hospital that screens all admitted patients for nasal MRSA carriage. Cases, defined as MRSA nasal carriers, were age and gender matched to controls, non-MRSA carriers. In-hospital interviews were conducted, and medical records were reviewed to obtain information on medical and household exposures. Multivariable conditional logistic regression was used to derive odds ratio (OR) estimates of association between MRSA carriage and medical and household exposures.ResultsIn total, 117 cases and 119 controls were recruited to participate. Risk factors for MRSA carriage included having household members who took antibiotics or were hospitalized (OR: 3.27; 95% Confidence Interval (CI): 1.24–8.57) and prior hospitalization with a positive MRSA screen (OR: 3.21; 95% CI: 1.12–9.23). A lower proportion of cases than controls were previously hospitalized without a past positive MRSA screen (OR: 0.40; 95% CI: 0.19–0.87).ConclusionThese findings suggest that household exposures are important determinants of MRSA nasal carriage in hospitalized patients screened at admission

The inflammatory microenvironment in colorectal neoplasia

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