1,095 research outputs found

    Preliminary studies of electromagnetic sounding of cometary nuclei

    Get PDF
    The internal structure of a comet could be determined with a spacecraft borne electromagnetic sounder. A dielectric profile of the comet could be produced in direct analogy with terrestrial glacier and ice sheet sounding experiments. This profile would allow the detection of a rocky core or ice layers if they exist, just as layers in the ice and the bedrock interface have been clearly observed through the Greenland ice sheet. It would also provide a gross estimate of the amount of dust in the icy region. Models for the response of the nucleus and cometary plasma to electromagnetic sounding are developed and used to derive experimental parameters. A point system design was completed. Preliminary engineering study results indicate that the sounder is well within the bounds of current space technology

    Angular momentum projection of cranked Hartree-Fock states: Application to terminating bands in A~44 nuclei

    Full text link
    We present the first systematic calculations based on the angular-momentum projection of cranked Slater determinants. We propose the Iy --> I scheme, by which one projects the angular momentum I from the 1D cranked state constrained to the average spin projection of =I. Calculations performed for the rotational band in 46Ti show that the AMP Iy --> I scheme offers a natural mechanism for correcting the cranking moment of inertia at low-spins and shifting the terminating state up by ~2 MeV, in accordance with data. We also apply this scheme to high-spin states near the band termination in A~44 nuclei, and compare results thereof with experimental data, shell-model calculations, and results of the approximate analytical symmetry-restoration method proposed previously.Comment: 9 RevTeX pages, 8 EPS figures, submitted to Physical Review

    Pattern measurements of a low-sidelobe horn antenna

    Get PDF
    The techniques and results of power pattern measurements of a corrugated horn antenna designed for low sidelobes are reported. The power pattern was measured to levels 90 dB below the main beam maximum in both the E- and H-planes. The measured patterns were found to be in good agreement with predictions from existing theory for the performance of corrugated scalar feeds

    Study of the structure of intermetalics from Fe - Al system after the hot rolling

    Get PDF
    This paper presents the results of structure analysis of Fe - Al alloys after hot rolling deformation. Microstructure analysis were performed before and after deformation using a scanning transmission electron microscopy (STEM) technique. The detailed quantities research of the structures was conducted using scanning electron microscopy (SEM) equipped with the gun with cold field emission and the detector of electron back scattering diffraction (EBSD)

    Cholesterol content and intramuscular collagen properties of pectoralis superficialis muscle of quail from different genetic groups

    Get PDF
    ABSTRACT To study growth performance and meat quality traits (cholesterol content and intramuscular collagen properties) of quail, 3 trials were carried out. Trial 1 used males of generation 19 of the egg type Japanese quail (Coturnix japonica) selected previously (until generation 17) for low (n = 8) or high (n = 7) yolk cholesterol content as well as an unselected control (n = 11). Trial 2 used males of meat Pharaoh quail selected earlier (generations 1 to 6 and 9 to 11) on the basis of BW decrease after periodic deprivation of food (high decrease of weight, n = 10; low decrease of weight, n = 8) and unselected control (n = 10). Trial 3 compared males of English White quail, Manchurian Golden quail, and British Range quail. The birds were raised to 35 d of age. Quail were fed ad libitum commercial diets according to age and had free access to water. At slaughter, all birds were individually weighed (after a fasting period of 12 h), stunned, and decapitated. After the refrigeration period (24 h at 4°C), the left pectoralis superficialis muscle was removed from the carcasses, weighed, vacuum packaged, and stored frozen (−40°C) for analyses of cholesterol and intramuscular collagen (IMC; collagen and crosslink concentration). In trial 1, divergent selection for yolk cholesterol content did not significantly influence pectoralis superficialis muscle weight and IMC crosslinking of Japanese quail, whereas it significantly reduced growth and IMC amount. In addition, it had greater effect on the amount of cholesterol in meat; in fact, the meat of quail with low yolk cholesterol content contained lower cholesterol (−36.6%) than that of birds with high yolk cholesterol content. In trial 2, divergent selection on the basis of Pharaoh quail BW decrease altered IMC crosslinking, leading to variability in meat tenderness of Pharaoh quail. In trial 3, English White quail were significantly heavier than the other breeds

    effects of in ovo injection of prebiotics and synbiotics on the productive performance and microstructural features of the superficial pectoral muscle in broiler chickens

    Get PDF
    ABSTRACT The aim of the study was to compare the effects of 2 prebiotics and 2 synbiotics injected in ovo on productivity parameters, quality, and microstructure of the superficial pectoral muscle in 35-day-old broiler chickens. On day 12 of incubation, 9,000 eggs Ross 308 were randomly divided into 5 experimental groups treated with different bioactives in ovo injected: C, control with physiological saline; PI, with 1.760 mg inulin; PB, with 0.528 mg of commercial prebiotic Bi2 tos; SI, with 1.760 mg inulin and 1,000 CFU Lactococcus lactis spp. lactis IBB SL1; SB, with 0.528 mg Bi2 tos and 1,000 CFU Lactococcus lactis spp. cremoris IBB SC1. The synbiotic solution contained 20 μl bacterial suspension and 180 μl prebiotic solution. For productive parameters and further tests ten male birds for each experimental group were used. The birds were slaughtered on day 35 of age. At slaughter, samples of the left pectoral muscles were taken and preserved by freezing in liquid nitrogen. The pH and color of the meat were evaluated at 45 min and 24 h post-mortem. Water holding capacity (WHC) was measured and expressed as the percentage of free water in meat. Microscopic specimens were analysed using MultiScan software for the measurement of the percentage of oxidative and glycolytic fibres and mean diameter of the muscle fibres. In ovo injection of prebiotics Bi2 tos had a positive effect on body weight. In prebiotic group (PI) a negative impact on hatchability was observed. Prebiotics and synbiotics had no influence on the yield of the carcass and pectoral muscle. Bioactive compounds had a significant effect on the quality of meat parameters such as: pH 24 h (PI and PB group), L* 45' (SI and SB group), and WHC (groups PB, SI, and SB). The analysis of the enzymatic profile showed a significant increase in the percentage of glycolytic fibres in the pectoral muscle from chicken treated with a synbiotic with the addition of inulin (group SI)

    quantitative trait loci associated with the humoral innate immune response in chickens were confirmed in a cross between green legged partridgelike and white leghorn

    Get PDF
    Natural antibodies (NA) create a crucial barrier at the initial steps of the innate humoral immune response. The main role of NA in the defense system is to bind the pathogens at early stages of infection. Different pathogens are recognized by the presence of highly conserved antigen determinant [e. g., lipopolysaccharide (LPS) in gram-negative bacteria or lipoteichoic acid (LTA) in gram-positive bacteria]. In chickens, a different genetic background of NA binds LPS and LTA antigens, encoded by different QTL. The main objective of this work was to confirm known QTL associated with LPS and LTA NA. For this purpose a chicken reference population was created by crossing 2 breeds: a commercial layer, White Leghorn, and a Polish indigenous chicken, Green-Legged Partridgelike. The chromosomal regions analyzed harbored to GGA3, GGA5, GGA6, GGA8, GGA9, GGA10, GGA14, GGA15, GGA18, and GGAZ. The data collected consisted of the NA titers binding LPS and LTA (determined by ELISA at 12 wk of age) as well as the genotypes (30 short tandem repeat markers; average of 3 markers/chromosome, collected for generations F(0), F(1), and F(2)). The analyses were performed with 3 statistical models (paternal and maternal half-sib, line cross, and linkage analysis and linkage disequilibrium) implemented in GridQTL software (http://www.gridqtl.org.uk/). The QTL study of humoral innate immune response traits resulted in the confirmation of 3 QTL associated with NA titers binding LPS (located on GGA9, GGA18, and GGAZ) and 2 QTL associated with NA titers binding LTA (located on GGA5 and GGA14). A set of candidate genes within the regions of the validated QTL has been proposed

    effect of in ovo administration of different synbiotics on carcass and meat quality traits in broiler chickens

    Get PDF
    ABSTRACT The aim of this study was to examine the effect of in ovo synbiotic administration on slaughter performance and meat quality traits of broiler chickens. On day 12 of incubation, 5,850 eggs (Cobb 500 FF) were randomly divided into 3 experimental groups and automatically injected in ovo with physiological saline (control, C) and 2 different synbiotic formulations (SYN1: Lactobacillus salivarius + galactooligosaccharides; SYN2: Lactobacillus plantarum + raffinose family oligosaccharides). After hatching, 240 males were randomly chosen (80 chicks per group) and split into 8 replicate pens (10 birds per pen). At 42 d of age, 15 birds per treatment were weighed and slaughtered. In ovo synbiotic administration had a low effect on investigated traits, but depends on the kind of synbiotic administered. Both synbiotic formulations did not affect final BW, weight, and yield of carcass and pectoral muscle (PM); likewise, physicochemical properties (pH, color, water holding capacity), intramuscular collagen properties, and cholesterol content of PM were not affected by treatment. Synbiotic administration reduced (P = 0.061) the lipid content compared with C group, markedly (

    Fine-tuned Sentiment Analysis of COVID-19 Vaccine-Related Social Media Data: Comparative Study

    Full text link
    This study investigated and compared public sentiment related to COVID-19 vaccines expressed on two popular social media platforms, Reddit and Twitter, harvested from January 1, 2020, to March 1, 2022. To accomplish this task, we created a fine-tuned DistilRoBERTa model to predict sentiments of approximately 9.5 million Tweets and 70 thousand Reddit comments. To fine-tune our model, our team manually labeled the sentiment of 3600 Tweets and then augmented our dataset by the method of back-translation. Text sentiment for each social media platform was then classified with our fine-tuned model using Python and the Huggingface sentiment analysis pipeline. Our results determined that the average sentiment expressed on Twitter was more negative (52% positive) than positive and the sentiment expressed on Reddit was more positive than negative (53% positive). Though average sentiment was found to vary between these social media platforms, both displayed similar behavior related to sentiment shared at key vaccine-related developments during the pandemic. Considering this similar trend in shared sentiment demonstrated across social media platforms, Twitter and Reddit continue to be valuable data sources that public health officials can utilize to strengthen vaccine confidence and combat misinformation. As the spread of misinformation poses a range of psychological and psychosocial risks (anxiety, fear, etc.), there is an urgency in understanding the public perspective and attitude toward shared falsities. Comprehensive educational delivery systems tailored to the population's expressed sentiments that facilitate digital literacy, health information-seeking behavior, and precision health promotion could aid in clarifying such misinformation.Comment: 11 Pages, 5 Figures, and 1 Tabl

    Attitudes Towards Body Organ Transplantation

    Get PDF
    The authors present the outcomes of a study on attitudes towards donation of one’s own body organs to others in case of potential donor’s clinical death after an accident. The results showed that life organs (e.g. lungs, liver) are more willingly donated than peripheral ones (e.g. fingers, eyes). Some personal values are positively related to this readiness, whereas religiosity negatively. Further research ideas are proposed
    corecore