Rust (Puccinia emaculata) Management and Impact on Biomass Yield in Switchgrass.

Rust, putatively caused by Puccinia emaculata, is a widespread and potentially damaging disease of switchgrass, a crop produced as feedstock for livestock and bioenergy. Azoxystrobin, chlorothalonil, and myclobutanil were applied at 1-, 2-, 3-, or 4-week intervals for 12 to 14 weeks to the vegetatively propagated switchgrass cultivar Cloud Nine to assess fungicide selection and application interval for the control of rust as well as the impact of this disease on switchgrass biomass yield. Although rust severity significantly differed among study years, azoxystrobin and myclobutanil were often equally and more effective than chlorothalonil at controlling rust, with superior disease control coming at shorter application intervals compared with extended application intervals. Year, product, application interval, and product × interval significantly impacted dry biomass yield, which was greatest in 2016 and lowest in 2014. Dry biomass yield protection was significantly better with azoxystrobin and myclobutanil applications than with chlorothalonil or no fungicide. Linear regression models with the final disease rating, as well as with the area under disease progress curve in each year, were significant, but coefficients of determination were low to moderate (0.21 < R2 < 0.60), indicating that rust response and subsequent disease impact on dry biomass yield were impacted by other factors. From our models, an estimated 3 to 5% biomass decline was calculated for each 10% increment in rust-related leaf necrosis observed at the final September rating date. With rust-related leaf necrosis ≥80% by 1 September in each of 4 study years, biomass yield may be reduced by 24 to 40% if rust problems are not managed in switchgrass crops.

In situ radiometric and exposure age dating of the martian surface.

We determined radiogenic and cosmogenic noble gases in a mudstone on the floor of Gale Crater. A K-Ar age of 4.21 ± 0.35 billion years represents a mixture of detrital and authigenic components and confirms the expected antiquity of rocks comprising the crater rim. Cosmic-ray-produced (3)He, (21)Ne, and (36)Ar yield concordant surface exposure ages of 78 ± 30 million years. Surface exposure occurred mainly in the present geomorphic setting rather than during primary erosion and transport. Our observations are consistent with mudstone deposition shortly after the Gale impact or possibly in a later event of rapid erosion and deposition. The mudstone remained buried until recent exposure by wind-driven scarp retreat. Sedimentary rocks exposed by this mechanism may thus offer the best potential for organic biomarker preservation against destruction by cosmic radiation.

Effect of academic affiliation and obstetric volume on clinical outcome and cost of childbirth.

OBJECTIVE: To determine whether the academic affiliation and obstetric volume of the delivering hospital has an impact on clinical and economic outcomes. METHODS: We performed a cross-sectional analysis of data for all births in the State of Maryland during 1996. Acute hospital discharge data were obtained from the publicly available Maryland Health Services Cost Review Commission database. Institutions were classified as community hospitals, community teaching hospitals, and academic medical centers. Principal outcome variables included cesarean birth and complication rates, total hospital charges, and length of stay. RESULTS: A total of 63,143 cases were identified for analysis. The cesarean delivery rate was lower among academic medical centers, compared with community teaching hospitals and community hospitals (18.4% compared with 24.3% and 21.2%, respectively). After adjustment for patient case-mix, the adjusted odds ratio (OR) for cesarean birth was 0.66 at academic medical centers and 1.23 at community teaching hospitals compared with community hospitals (P <.01). Rates of episiotomy and serious complications were lower at academic medical centers compared with community hospitals. Adjusted total hospital charges were lower and length of stay was shorter for community hospitals compared with academic medical centers ($2937 compared with $3564 and 2.2 days compared with 2.5 days, respectively). CONCLUSION: Hospital academic affiliation was an important predictor of clinical outcomes. Better clinical outcomes were found primarily among patients at academic medical centers, although these institutions demonstrated moderately higher resource utilization, compared with community hospitals.

MMPI and MMPI-2 profile and code type congruence in a brain-injured sample.

Examined the comparability of the Minnesota Multiphasic Personality Inventory (MMPI) and Minnesota Multiphasic Personality Inventory-2 (MMPI-2) in a sample of brain-injured patients. There were 53 patients (36 males, 17 females; M age = 27.25, SD = 11.45), the majority of whom had suffered a closed-head injury. The MMPI-2 and MMPI items were administered in the context of an extensive neuropsychological examination. Results revealed a lack of congruence between the MMPI and MMPI-2 when the entire profile was compared using profile analysis. Analyses of code types found congruence to be high for single point elevations but modest for 2-point code types. The degree of congruence appears related to the nature of analysis, and for clinical purposes, code-type interpretation may be most relevant. These results provide some support for the congruence of the MMPI and MMPI-2 for brain-injured patients, but particular caution should be exercised in the interpretation of 2-point code types.

Cardiorespiratory effects of antagonism of diazepam sedation with flumazenil in patients with cardiac disease.

The specific benzodiazepine antagonist flumazenil is currently under intense study. Despite much clinical experience, no detailed invasive hemodynamic studies of its use in cardiac patients have been published. In the present study, hemodynamic and respiratory variables were measured in 10 cardiac patients undergoing catheterization of the right and left sides of the heart, before and after sedation with intravenous diazepam, and after reversal of sedation with flumazenil. A sleep dose of diazepam (12.2 +/- 5.1 mg, mean +/- SD) caused only slight decreases in mean arterial pressure (103 +/- 12 to 98 +/- 14 mm Hg; P less than 0.05), pulmonary capillary wedge pressure (13.2 +/- 6.3 to 11.7 +/- 6.6 mm Hg; P less than 0.05), and left ventricular end-diastolic pressure (20.8 +/- 7.5 to 17.3 +/- 10.0 mm Hg; P less than 0.05), with no significant changes in respiratory gas homeostasis. Intravenous flumazenil (0.22 +/- 0.07 mg) resulted in spontaneous awakening and return to full orientation, yet caused no significant alteration in either hemodynamic or respiratory variables measured. Reversal of diazepam-induced sedation by flumazenil in cardiac patients appears safe and effective.

Neuropsychological deficit and emotional disturbance in head-injured patients.

The relationship between neuropsychological deficit and emotional disturbance was examined in a sample of 124 patients who sustained work-related head injuries. Most injuries met criteria for minor head injury. Since all patients were receiving compensation, the relationship between emotional disturbance and neuro-behavioral deficit does not appear to be related to compensation or litigation factors. There was a positive relationship between degree of neurobehavioral and emotional abnormality. This was not due to the interval between injury and examination, and did not appear to be related to duration of unconsciousness or amnesia, or to the presence of skull fracture or posttraumatic seizures. The findings are discussed in relation to previous research and to their implications regarding posttraumatic emotional adjustment.

Emotional adjustment in compensated head injury patients.

Patterns of emotional adjustment based on the Minnesota Multiphasic Personality Inventory (MMPI) were examined in a group of 124 patients who had suffered head injuries, reported postconcussional symptoms, and were receiving compensation. Cluster analytical procedures were used to identify subgroups. The sample was divided into two equivalent groups for purposes of crossvalidation. The results of the analyses in the two samples yielded similar patterns. Within each subgroup, the groups differed on the level and pattern of emotional disturbance. Approximately 65% of the sample had normal profiles or only mild elevations on the "neurotic" scales. The largest subgroup had mild elevations. After the exclusion of invalid profiles, a small proportion had severe disturbances. The injury-related neurological characteristics of these groups are similar. These findings are discussed in terms of the previous literature on the effects of compensation on posttraumatic personality adjustment.