680 research outputs found
Molecular Beam Measurement of the Hyperfine Structure of 133Cs19F
The magnitudes and signs of the hyperfine interaction constants for 133Cs19F in the J = 1, v = 0, 1, 2 states have been measured with a molecular beam electric resonance spectrometer. The results for v = 0 are: eQ1q1 = 1.2370(13) MHz, c1 = 0.70(7)kHz, c2 = 15.1(6)kHz, c3 = 0.92(12)kHz, c4 = 0.61(10)kHz. The numbers in parentheses are uncertainties in units of the last digit given. eQ1q1 is the quadrupole coupling constant for the cesium nucleus, c1 and c2 are the spinārotation coupling constants for the cesium and fluorine nuclei, respectively, and c3 and c4 are the coupling constants for the tensor and scalar parts of the nuclear spināspin interaction. These constants are obtained from the radioāfrequency spectrum of CsF taken under veryweakāfield conditions (Edc = 1.5 V/cm; H<0.05 Oe); some previously ignored contributions of the fluorine spinārotation interaction and the spināspin interaction are clearly evident. The observed variation in eQ1q1 with vibrational state shows only qualitative agreement with theory. An appendix gives compact expressions for the veryāweakāfield hfs energy levels of a 1Ī£ molecule in which only one nucleus has a quadrupole moment.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70928/2/JCPSA6-47-10-3896-1.pd
Molecular Beam Measurement of the Hyperfine Structure of 85Rb19F
Radioāfrequency transitions between the hfs levels of the J=1 rotational state in 85Rb19F have been observed using a molecular beam electric resonance spectrometer. From these spectra we have obtained values for the constant eq1Q1, which characterizes the interaction between the electric quadrupole moment of the Rb nucleus with the molecular electricāfield gradient; for the constants c1 and c2 which characterize the magnetic interaction between the Rb and F nuclei, respectively, and the rotational angular momentum J of the molecule; and for the constants c3 and c4 which describe the magnetic coupling of the two nuclear spins. Measurements have been made on the firstāfive vibrational states. The results for v=0 areeq1Q1=(ā70.342Ā±0.001)MHz,c1=(+0.52Ā±0.02)kHz,c2=(+10.615Ā±0.06)kHz,c3=(+0.80Ā±0.06)kHz,c4=(+0.15Ā±0.05)kHz.Values of these constants for v=1, 2, 3, and 4 are given with somewhat less precision.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69352/2/JCPSA6-45-10-3731-1.pd
Triple Resonance Method for Molecular hfs Spectroscopy: Measurements on 133Cs19F
Three sequential oscillatory fields are employed in a molecular beam electric resonance spectrometer in order to observe molecular hfs transitions which do not obey the criteria for observability in the usual beam apparatus. The triple resonance method has been used to examine the hfs of CsF under conditions of very weak external fields. The method shows considerable promise for the detailed study of molecular hfs when more than one nucleus has a quadrupole moment, and for the observation of transitions at audio frequencies between closely spaced molecular energy levels.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70906/2/JCPSA6-47-10-3904-1.pd
Machine learning reveals interhemispheric somatosensory coherence as indicator of anesthetic depth
The goal of this study was to identify features in mouse electrocorticogram recordings that indicate the depth of anesthesia as approximated by the administered anesthetic dosage. Anesthetic depth in laboratory animals must be precisely monitored and controlled. However, for the most common lab species (mice) few indicators useful for monitoring anesthetic depth have been established. We used electrocorticogram recordings in mice, coupled with peripheral stimulation, in order to identify features of brain activity modulated by isoflurane anesthesia and explored their usefulness in monitoring anesthetic depth through machine learning techniques. Using a gradient boosting regressor framework we identified interhemispheric somatosensory coherence as the most informative and reliable electrocorticogram feature for determining anesthetic depth, yielding good generalization and performance over many subjects. Knowing that interhemispheric somatosensory coherence indicates the effectively administered isoflurane concentration is an important step for establishing better anesthetic monitoring protocols and closed-loop systems for animal surgeries
Effect of immune system stimulation and divergent selection for residual feed intake on digestive capacity of the small intestine in growing pigs
Residual feed intake (RFI) is a measure of feed efficiency that reflects differences in the efficiency of the use of feed for maintenance and growth. The consequences of genetic selection for RFI on intestinal nutrient digestion capacity, particularly during immune system stimulation (ISS), are poorly documented. Our objective was to evaluate the impact of ISS and genetic selection for RFI on apparent ileal digestibility (AID) of nutrients, and intestinal nutrient transport and barrier function
What makes for prize-winning television?
We investigate the determinants of success in four international television awards festivals between 1994 and 2012. We find that countries with larger markets and greater expenditure on public broadcasting tend to win more awards, but that the degree of concentration in the market for television and rates of penetration of pay-per-view television are unrelated to success. These findings are consistent with general industrial organisation literature on quality and market size, and with media policy literature on public service broadcasting acting as a force for quality. However, we also find that āhome countriesā enjoy a strong advantage in these festivals, which is not consistent with festival success acting as a pure proxy for television quality
Defining childhood severe falciparum malaria for intervention studies.
Background Clinical trials of interventions designed to prevent severe falciparum malaria in children require a clear endpoint. The internationally accepted definition of severe malaria is sensitive, and appropriate for clinical purposes. However, this definition includes individuals with severe nonmalarial disease and coincident parasitaemia, so may lack specificity in vaccine trials. Although there is no āgold standardā individual test for severe malaria, malaria-attributable fractions (MAFs) can be estimated among groups of children using a logistic model, which we use to test the suitability of various case definitions as trial endpoints. Methods and Findings A total of 4,583 blood samples were taken from well children in cross-sectional surveys and from 1,361 children admitted to a Kenyan District hospital with severe disease. Among children under 2 y old with severe disease and over 2,500 parasites per microliter of blood, the MAFs were above 85% in moderate- and low-transmission areas, but only 61% in a high-transmission area. HIV and malnutrition were not associated with reduced MAFs, but gastroenteritis with severe dehydration (defined by reduced skin turgor), lower respiratory tract infection (clinician's final diagnosis), meningitis (on cerebrospinal fluid [CSF] examination), and bacteraemia were associated with reduced MAFs. The overall MAF was 85% (95% confidence interval [CI] 83.8%ā86.1%) without excluding these conditions, 89% (95% CI 88.4%ā90.2%) after exclusions, and 95% (95% CI 94.0%ā95.5%) when a threshold of 2,500 parasites/Ī¼l was also applied. Applying a threshold and exclusion criteria reduced sensitivity to 80% (95% CI 77%ā83%). Conclusions The specificity of a case definition for severe malaria is improved by applying a parasite density threshold and by excluding children with meningitis, lower respiratory tract infection (clinician's diagnosis), bacteraemia, and gastroenteritis with severe dehydration, but not by excluding children with HIV or malnutrition
Human gut dendritic cells drive aberrant gut-specific T-cell responses in ulcerative colitis, characterized by increased IL-4 production and loss of IL-22 and IFNĪ³
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