4,325 research outputs found
MSFC Skylab instrumentation and communication system mission evaluation
An evaluation of the in-orbit performance of the instrumentation and communications systems installed on Skylab is presented. Performance is compared with functional requirements and the fidelity of communications. In-orbit performance includes processing engineering, scientific, experiment, and biomedical data, implementing ground-generated commands, audio and video communication, generating rendezvous ranging information, and radio frequency transmission and reception. A history of the system evolution based on the functional requirements and a physical description of the launch configuration is included. The report affirms that the instrumentation and communication system satisfied all imposed requirements
Widespread stop-codon recoding in bacteriophages may regulate translation of lytic genes
Bacteriophages (phages) are obligate parasites that use host bacterial translation machinery to produce viral proteins. However, some phages have alternative genetic codes with reassigned stop codons that are predicted to be incompatible with bacterial translation systems. We analysed 9,422 phage genomes and found that stop-codon recoding has evolved in diverse clades of phages that infect bacteria present in both human and animal gut microbiota. Recoded stop codons are particularly over-represented in phage structural and lysis genes. We propose that recoded stop codons might function to prevent premature production of late-stage proteins. Stop-codon recoding has evolved several times in closely related lineages, which suggests that adaptive recoding can occur over very short evolutionary timescales
On the Energy Transfer Performance of Mechanical Nanoresonators Coupled with Electromagnetic Fields
We study the energy transfer performance in electrically and magnetically
coupled mechanical nanoresonators. Using the resonant scattering theory, we
show that magnetically coupled resonators can achieve the same energy transfer
performance as for their electrically coupled counterparts, or even outperform
them within the scale of interest. Magnetic and electric coupling are compared
in the Nanotube Radio, a realistic example of a nano-scale mechanical
resonator. The energy transfer performance is also discussed for a newly
proposed bio-nanoresonator composed of a magnetosomes coated with a net of
protein fibers.Comment: 9 Pages, 3 Figure
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Discordant Risk: Overweight and cardiometabolic risk in Chinese adults
Recent US work identifies âmetabolically healthy overweightâ and âmetabolically at risk normal weightâ individuals. Less is known for modernizing countries with recent increased obesity. Fasting blood samples, anthropometry and blood pressure from 8,233 adults aged 18â98 in the 2009 nationwide China Health and Nutrition Survey, were used to determine prevalence of overweight (Asian cut point, BMIâ„23 kg/m2) and five risk factors [pre-diabetes/diabetes (HbA1câ„5.7%) inflammation (hsCRP â„3 mg/L), pre-hypertension/hypertension (SBP/DBPâ„130/85 mmHg), high triglycerides (â„150 mg/dL), low high-density lipoprotein cholesterol (70 years: 73%). Abdominal obesity was highly predictive of metabolic risk, irrespective of overweight (e.g., âmetabolically at risk overweightâ relative to âmetabolically healthy normal weightâ [men: Relative Risk Ratio (RRR) =39.06; 95% Confidence Interval (CI): 23.47, 65.00; women: RRR=22.26; 95% CI: 17.49, 28.33]). To conclude, a large proportion of Chinese adults have metabolic abnormalities. High hypertension risk with age, irrespective of obesity underlies the low prevalence of metabolically healthy overweight. Screening for cardiometabolic-related outcomes dependent upon overweight will likely miss a large portion of the Chinese at-risk population
Search for electroweak production of charginos and neutralinos in WH events in proton-proton collisions at sâ=13 TeV
Results are reported from a search for physics beyond the standard model in proton-proton collision events with a charged lepton (electron or muon), two jets identified as originating from a bottom quark decay, and significant imbalance in the transverse momentum. The search was performed using a data sample corresponding to 35.9 fbâ1, collected by the CMS experiment in 2016 at sâ=13 TeV. Events with this signature can arise, for example, from the electroweak production of gauginos, which are predicted in models based on supersymmetry. The event yields observed in data are consistent with the estimated standard model backgrounds. Limits are obtained on the cross sections for chargino-neutralino (Ï~±1Ï~02) production in a simplified model of supersymmetry with the decays ϱ1âW±Ï~01andÏ~02âHÏ01. Values of mÏ~±1 between 220 and 490 GeV are excluded at 95% confidence level by this search when the Ï~01 is massless, and values of mÏ~01 are 1 excluded up to 110 GeV for mÏ~±1â450 GeV
The emergence of cardiometabolic disease risk in Chinese children and adults: consequences of changes in diet, physical activity and obesity: Cardiometabolic disease risk in China
Strong secular declines in physical activity, increased fat and salt intake, and increased obesity, especially abdominal obesity, mark China's recent nutrition transition. The China Health and Nutrition 2009 Survey collected anthropometry, blood pressure, and fasting blood samples from more than 9,000 individuals â„ seven years of age. We focus on elevated blood pressure and plasma markers of diabetes, inflammation, and dyslipidemia. We used international definitions of cardiometabolic risk and estimated age- and sex-specific prevalence ratios for each outcome for high waist circumference or overweight. We used logistic regression to assess each risk factor's association with diet, physical activity, overweight, and abdominal obesity. Cardiometabolic risk prevalence was high in all age groups Prevalence ratios for most risk factors were nearly doubled for overweight or high waist circumference groups. Prevalence ratios were higher in younger than older adults. Low physical activity consistently predicted higher cardiometabolic risk across most outcomes and age-sex groups. The co-occurrence of overweight and high waist circumference was highly predictive of dyslipidemia, elevated glycated hemoglobin, and diabetes. High prevalence of cardiometabolic risk factors and their strong association with weight status and abdominal obesity in young adults portend increases in cardiometabolic morbidity and mortality. Early interventions will be required to reverse trends
Tuning of the Fano Effect through a Quantum Dot in an Aharonov-Bohm Interferometer
The Fano effect, which arises from an interference between a localized state
and the continuum, reveals a fundamental aspect of quantum mechanics. We have
realized a tunable Fano system in a quantum dot (QD) in an Aharonov-Bohm
interferometer, which is the first convincing demonstration of this effect in
mesoscopic systems. With the aid of the continuum, the localized state inside
the QD acquires itinerancy over the system even in the Coulomb blockade.
Through tuning of the parameters, which is an advantage of the present system,
unique properties of the Fano effect on the phase and coherence of electrons
have been revealed.Comment: REVTEX, 4 pages, 4 figures included. Discussion and figures are
improved. Accepted for publication in Phys. Rev. Let
Effect of Intragastric pH on the Absorption of Oral Zinc Acetate and Zinc Oxide in Young Healthy Volunteers
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142255/1/jpen0393.pd
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