Troubleshooting Time-Dependent Density-Functional Theory for Photochemical Applications: Oxirane

The development of analytic-gradient methodology for excited states within conventional time-dependent density-functional theory (TDDFT) would seem to offer a relatively inexpensive alternative to better established quantum-chemical approaches for the modeling of photochemical reactions. However, even though TDDFT is formally exact, practical calculations involve the use of approximate functionals, in particular the TDDFT adiabatic approximation, whose use in photochemical applications must be further validated. Here, we investigate the prototypical case of the symmetric CC ring opening of oxirane. We demonstrate by direct comparison with the results of high-quality quantum Monte Carlo calculations that, far from being an approximation on TDDFT, the Tamm-Dancoff approximation (TDA) is a practical necessity for avoiding triplet instabilities and singlet near instabilities, thus helping maintain energetically reasonable excited-state potential energy surfaces during bond breaking. Other difficulties one would encounter in modeling oxirane photodynamics are pointed out but none of these is likely to prevent a qualitatively correct TDDFT/TDA description of photochemistry in this prototypical molecule.Comment: 19 pages, 17 figures, submitted to the Journal of Chemical Physic

Inhalation therapy during acute asthma : the role of a combined steroid and beta-stimulant preparation

CITATION: Joubert, J. R., Burger, G. & Shephard, E. 1985. Inhalation therapy during acute asthma : the role of a combined steroid and beta-stimulant preparation. South African Medical Journal, 68:381-384.The original publication is available at http://www.samj.org.zaA compound consisting of a β-stimulant, salbutamol (100 μg/puff), and a steroid, beclomethasone diproprionate (50 μg/puff), was studied to test the hypothesis that the corticosteroid could enhance the bronchodilator proporties of the β-stimulant during chronic asthma and simulated acute attacks (antigen challenge). Conventional doses (200 μg and 100 μg of salbutamol and beclomethasone respectively) were compared using a schedule which included a second administration 1 hour later. The results obtained on the baseline bronchial responsiveness of chronic asthmatics and during the delayed asthmatic response (simulated acute asthma) were similar. The compound was as effective as salbutamol alone but not more so. A significantly greater bronchodilator response was recorded in all patients after the second administration of both the compound and salbutamol alone. The practical advantages of having one rather than two inhalers are evident, but the appropriate application of this compound agent, probably in a prophylactic role, must be defined.Publisher’s versio

Energy deposited by neutrons and gamma rays in the cryogenic system of SISSI

International audienc

Developing fencing policies in dryland ecosystems

The daily energy requirements of animals are determined by a combination of physical and physiological factors, but food availability may challenge the capacity to meet nutritional needs. Western gorillas (Gorilla gorilla) are an interesting model for investigating this topic because they are folivore-frugivores that adjust their diet and activities to seasonal variation in fruit availability. Observations of one habituated group of western gorillas in Bai-Hokou, Central African Republic (December 2004-December 2005) were used to examine seasonal variation in diet quality and nutritional intake. We tested if during the high fruit season the food consumed by western gorillas was higher in quality (higher in energy, sugar, fat but lower in fibre and antifeedants) than during the low fruit season. Food consumed during the high fruit season was higher in digestible energy, but not any other macronutrients. Second, we investigated whether the gorillas increased their daily intake of carbohydrates, metabolizable energy (KCal/g OM), or other nutrients during the high fruit season. Intake of dry matter, fibers, fat, protein and the majority of minerals and phenols decreased with increased frugivory and there was some indication of seasonal variation in intake of energy (KCal/g OM), tannins, protein/fiber ratio, and iron. Intake of non-structural carbohydrates and sugars was not influenced by fruit availability. Gorillas are probably able to extract large quantities of energy via fermentation since they rely on proteinaceous leaves during the low fruit season. Macronutrients and micronutrients, but not digestible energy, may be limited for them during times of low fruit availability because they are hind-gut fermenters. We discuss the advantages of seasonal frugivores having large dietary breath and flexibility, significant characteristics to consider in the conservation strategies of endangered species

The SISSI project : an intense secondary ion source using superconducting solenoid lenses

International audienceIn order to make a better use of the higher beam intensities soon available at GANIL, a proposal called SISSI was presented in 1989. It consists of a set of two superconducting solenoid lenses of very short focal length (0.6 m). The fist solenoid is used to sharply focus the incoming beam on a fast moving target. The second increases the angular acceptance of the beam line downstream the target for charged reaction products. Calculations show that from a 0.4-mm-diameter beam spot on the target, an acceptance angle of up to 80 mrad will be reached without significant emittance growth due to aberration effects. Technical aspects of that project are presente

The Relationships between Fitness Assessments, Fitness Levels and Coronary Heart Disease Risk Markers in Police Officers

Given the physical nature of a position in law enforcement, the assessment of cardiovascular (CV) health as well as muscular strength and endurance is paramount to ensuring the safety of these personnel and the citizens they serve. The present study retrospectively examined correlations between several markers of CV and muscular fitness for 65 local police officers (8 female, average age 35.6 ± 9.0 yrs, height 70.5 ± 2.8 in, weight 91.8 ± 18.7 kg, VO2 33.0 ± 5.3 mL/kg/min) taken from their annual screening including a graded exercise test (GXT; Bruce protocol), pushups completed in 1 minute, situps completed in 1 minute, handgrip strength, body composition (through DEXA and circumference measures) and bloodwork. Maximal oxygen uptake (VO2max) was estimated using the Foster equation. Coronary heart disease risk (CHD risk) was calculated using the online NIH 10-year heart attack risk calculator, which uses age, gender, total cholesterol, HDL cholesterol, smoking status, and blood pressure status in its algorithm. Significance was determined using an alpha level of 0.05. Interestingly, there was no significant correlation between VO2max and CHD risk (p = 0.1851). Apart from risk markers included in the risk calculation, CHD risk was significantly correlated with waist-hip ratio (r = 0.24739), and LDL cholesterol (r = 0.39117). VO2max was significantly negatively correlated with fat mass (r = -0.51849), body fat percentage (%BF; r = -0.64297), total cholesterol (TC; r = -0.3371), and LDL cholesterol (r = -0.267). Positive correlations were found between VO2max and other measures of fitness such as pushups (r = 0.54274), situps (r = 0.3282), and handgrip strength (r = 0.32041). As for body composition measures, %BF was significantly positively correlated with TC (r = 0.30188), systolic blood pressure (r = 0.28795), LDL cholesterol (r = 0.26533), and fasting glucose (r = 0.26536), but negatively correlated with fitness markers such as pushups (r = -0.58599), situps (r = -0.43604), and handgrip strength (r = -0.32393). Lean mass was significantly correlated with handgrip strength (r = 0.71835), though not pushups, situps or VO2max. Waist circumference was significantly negatively correlated with HDL cholesterol (r = -0.39202). Additionally, 62 of the participants (7 female) completed both a 1.5 mile run and GXT, allowing for a comparison of a submaximal to a maximal fitness assessment of CV fitness. Time to complete 1.5 miles was significantly correlated to GXT VO2max, with a Pearson correlation coefficient of -0.79593. Overall, relationships found between health markers, fitness, and CHD risk in this sample were in line with previous research on CHD risk factors and the assessment of CV and muscular fitness

Aquatic Treadmill Training Reduces Blood Pressure Reactivity to Acute Graded Exercise in Previously Sedentary Adults

Endurance exercise may reduce blood pressure and improve vasodilatory capacity thereby blunting the hypertensive response to stress. To test the efficacy of a novel model of low-impact endurance training, the aquatic-based treadmill (ATM), to improve blood pressure parameters, we recruited 60 sedentary adults and randomized to 12-weeks of either ATM (n = 36 [19 men, 17 women] , 41±2 yr, 173.58 ±1.58cm, 93.19 ±3.15kg) or land-based treadmill (LTM, n = 24 [11 men, 13 women], 42 ±2yr, 170.39 ±1.94cm, 88.14 ±3.6kg) training; 3sessions·wk-1, progressing to 500 kcal·session-1, 85% VO2max. The maximal Bruce treadmill test protocol was performed before and after training with blood pressures measured prior to, at the end of each stage, and for 5 minutes following exercise testing. Twelve subjects (5 ATM, 7 LTM) volunteered for biopsies of the vastus lateralis before and after training, and muscle samples were assessed for eNOS content. Blood pressure data were analyzed using group by training ANCOVA repeated across training, α = 0.05. Data obtained from muscle sample analysis were analyzed using group by training ANOVA repeated across training α = 0.05. Training reduced systolic blood pressure (9- 18.2mmHg), diastolic blood pressure (3.2-8.1 mmHg), mean arterial pressure (4.8-8.3mmHg), pulse pressure (7.5-15mmHg), and rate pressure product (1.8-3.9 bpm·mm Hg·103) during exercise stress and recovery in the ATM group, but not in the LTM group. Additionally, the ATM group, but not the LTM group, displayed a 31% increase in skeletal muscle eNOS content following training. Both groups improved VO2max (+3.6mL O2·kg-1·min-1), but resting blood pressure was not changed following training. These data support the use of ATM training as a novel therapeutic modality to combat hypertension

Detection of [O I] 63 <i>μ</i>m in absorption toward Sgr B2

A high signal-to-noise 52-90 μm spectrum is presented for the central part of the Sagittarius B2 complex. The data were obtained with the Long Wavelength Spectrometer on board the Infrared Space Observatory (ISO). The [O I] 63 μm line is detected in absorption even at the grating spectral resolution of 0.29 μm. A lower limit for the column density of atomic oxygen of the order of 1019 cm-2 is derived. This implies that more than 40% of the interstellar oxygen must be in atomic form along the line of sight toward the Sgr B2 molecular cloud