Study of a BGO calorimeter using electron and hadron beams from 1 to 50 GeV

A calorimeter of 25 bismuth germanate (BGO) crystals equipped with silicon photodiode readout has been tested at the CERN SPS in the energy range 1–50 GeV. The response for electrons has been shown to be linear in this energy range and the rms resolution obtained ( ) is approximately 1%, for E > 4 GeV. The electron/pion separation was found to be better than 1:500 in the energy range 1–20 GeV. Data on lateral and longitudinal shower development were compared with the results of a Monte Carlo simulation using the SLAC-EGS program and found to be in good agreement.     

Transparent monolithic zirconia gels: effects of acetylacetone content on gelation

Transparent yttria-stabilized zirconia monolithic gels were synthesized under controlled conditions for hydrolysis and chemical polymerization. The influence of acetylacetone on the previous chemical reactions was explored, and a plausible explanation was proposed concerning the outstanding role of this additive during the gelation process. Small-angle X-ray scattering was used to estimate the size of the polymeric species and to investigate the influence of acetylacetone on the structure of the gels prepared.     

Drying Kinetics of a Porous Spherical Particle and the Inversion Temperature

A model is presented for drying of a single porous particle with superheated steam and humid air. Experimental data for spherical porous ceramic particle reported in the literature were used for the validation of the model. An inversion temperature at which the evaporation rates within superheated steam and humid air are equal was predicted. The effect of thermophysical properties of the particle (permeability 10^-14 - 10^-17 m², diameter 3 × 10^-3 - 10 × 10^-3 m) and operating variables (gas mass flux 0.26 - 0.78 kg m^-2 s^-1, drying agent temperature 120-200°C) is tested. The inversion temperature is shown to be affected by the thermophysical properties of the porous particle and of the drying agent.     

Dynamique motivationnelle de l'epuisement et du bien-etre chez des enseignants africains.

This study examines the links between antecedents and consequences of Gabonese teachers' (N= 152) work motivation. The theoretical underpinnings are based on the Motivational Model of Job Burnout (MMJB) which is grounded in Self-Determination Theory (SDT) and states that the more supervisors satisfy an employee's need for self-determination, competence, and relatedness, the more self-determined is the latter's work motivation. The level of self-determined motivation has an impact on job satisfaction, which in turn determines life satisfaction. Higher levels of self-determined motivation also buffer emotional exhaustion and psychological distress. The model was confirmed via structural equation modeling and provides support for the validity and generalizability of the MMJB and SDT. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Quantitative measurement of a new synthetic hetrazepine derivative, BN50730, in human plasma and urine by combined liquid chromatography-negative chemical ionization mass spectrometry using a particle beam interface

A new simple and sensitive assay has been developed for the quantitative measurement of BN50730 at the picomole level in human plasma and urine. The drug and the internal standard (BN50765) were measured by combined liquid chromatography-negative chemical ionization mass spectrometry with methane as the reagent gas. A simple solid-liquid extraction procedure was used to isolate BN50730 from complex biological matrices. Mild operating conditions were required to assay the parent drug with a particle beam interface from Hewlett-Packard. The mass spectrometer was tuned to monitor the intense ion m/z 333, which was generated in the ion source by a dissociative capture process. This assay was performed with 1 ml of plasma or 0.1 ml of urine, and the quantification limit of the method was statistically calculated as 1 ng ml-1. The very low relative standard deviation and mean percentage of error calculated during the different within-day or between-day repeatability assays clearly demonstrate the ruggedness of the technique for the routine determination of BN50730 in the biological fluids. Some preliminary results on the pharmacokinetics of the drug are presented to illustrate the applicability of this new powerful LC-MS method.     

Fast point spread function computation from aperture functions in high-resolution positron emission tomography

The problem of extracting point spread functions from detector aperture functions in high-resolution PET is addressed. In the limit of very small size detectors relative to the ring dimensions, assumptions are made that lead to a fast and simple computation model yielding point spread functions with negligible errors due to the reconstruction algorithm. The methods allows one to assess accurately the intrinsic performance of a PET tomograph, and it appears to be adequate to relate the imaging capabilities in every point of the camera reconstruction field to the geometric and physical characteristics of the detection system. The method was developed as an investigation tool to help design the next generation of very-high-resolution PET tomographs.     

Identification of leek-moth and diamondback-moth frass volatiles that stimulate parasitoid,Diadromus pulchellus

Acrolepiopsis assectella andPlutella xylostella frass volatiles, trapped on Tenax GC, were examined by capillary gas chromatography. In both moths, the same three disulfides, dimethyl, dipropyl, and methyl propyl, were the most abundant substances, but in different proportions. The synthetic disulfides elicited the same behavioral response by the parasitoid,Diadromus pulchellus as frass. The plant origin of these substances is discussed.     

Pathology of arrhythmogenic right ventricular cardiomyopathy/dysplasia--an autopsy study of 20 forensic cases

The effects of postpartum energy intake, restricted suckling, and cow-calf isolation on concentrations of LH, FSH, growth hormone, and insulin-like growth factor-I (IGF-I) and on postpartum anestrous interval were determined by randomly allocating beef cows with a mean body condition score of 2.3 +/- 0.1 to receive either 80 MJ metabolizable energy (low-energy diet [L]; n = 51) or 120 MJ metabolizable energy (high-energy diet [H]; n = 52) per cow per day from calving. At 30 days postpartum, cows within diet were randomized to 1) have continued full access to their calves from birth to weaning (ad libitum suckling: ADLIB), 2) be suckled once-daily with their calves penned adjacent (restricted suckling, adjacent: RESADJ), 3) be isolated from all calves except for a once-daily suckling period (restricted suckling, isolated: RESISO). The mean postpartum interval was similar (p > 0.10) for L and H cows (62 and 63 days, respectively). RESADJ cows had a shorter (p < 0.05) postpartum interval than ADLIB cows, and RESISO cows had a shorter interval (p < 0.05) than RESADJ cows, with all effects independent (p > 0.10) of diet. FSH secretion pattern was not affected by diet, suckling treatment, sequential follicle wave number, or follicle wave retrospectively realigned to emergence of first ovulatory wave. Within 5 days of suckling restriction and calf isolation, the number of LH pulses increased from 0.18 to 0.48 pulses per hour (p < 0.05). Both mean LH and the mean number of LH pulses increased linearly (p < 0.01) during the six follicle waves up to the first ovulatory wave. From 80 days before, until the time of, first ovulation, growth hormone decreased (p < 0.05) while IGF-I increased (p < 0.05), irrespective of treatment. The results indicate that the "suckling effect" in beef cows is the major factor affecting the duration of the postpartum interval and suggests that the maternal bond is more important than suckling in regulating LH pulse frequency, the key endocrine factor determining whether or not a dominant follicles ovulates. Removal of the suckling effect resulted in a rapid increase in LH pulse frequency, which was not dependent on level of postpartum nutrition, at least within the nutritional limits of this study. Mean concentrations of FSH, unlike LH, did not vary with follicle wave number, suggesting that lack of FSH is not a major factor delaying the resumption of ovulation in postpartum beef cows.