280 research outputs found
Stability of Neutrinos in the Singlet Majoron Model
We show that there is no one-loop enhancement of the rate for a light
neutrino to decay into a lighter neutrino plus a majoron, contrary to a recent
claim. Thus the light neutrinos must satisfy the cosmological bound of having
masses less than 35 eV in the singlet majoron model, or else violate the
constraint imposed by galaxy formation. In the latter case, could
have a mass between 40 and 500 keV, while satisfying all other cosmological
constraints.Comment: 11 pp., latex, UMN-TH-1218-93. Correct nucleosynthesis bound of 500
keV on nu_tau mass is incorporated; one-loop electroweak contribution to
neutrino mass is correcte
Farm level technical efficiency for pulse production in India
Pulses are complementary to cereals both in production as well as in consumption. During the production process, pulses help in improving sustainability by (i) fixing the atmospheric nitrogen into the soil (ii) consuming less water and (iii) controlling diseases and pests. On consumption front, pulses reduce malnutrition and improve human health being a rich and most viable source of protein for vegetarians and poor people. Realizing the importance of pulses, the government of India announces various schemes and programs from time to time to promote the cultivation of pulses in the country. However, pulse production in India has not achieved the targeted level. The paper analyses the production trend of pulses over the last decade and identifies the gap between the targets and achievements. Plot level data from cost of cultivation scheme across major pulses growing states has been used to estimate technical efficiencies of the pulses using data envelopment analysis. The paper also highlights the yield gap of the pulses across major pulse growing states and suggests suitable measures for improving farm level profitability and sustainability by increasing technical efficiency. The study postulated the hypothesis that technical efficiency of the pulses is low and the yield potential of the pulses are not fully harnessed. The results revealed that increase of technical efficiency by 1% will reduce the yield gap by 9 kg per ha and increase total pulse production of the country by 225 thousand tons
Miscarriage rates after dehydroepiandrosterone (DHEA) supplementation in women with diminished ovarian reserve: a case control study
<p>Abstract</p> <p>Background</p> <p>Dehydroepinadrosterone (DHEA) supplementation improves pregnancy chances in women with diminished ovarian reserve (DOR), by possibly reducing aneuploidy. Since a large majority of spontaneous miscarriages are associated with aneuploidy, one can speculate that DHEA supplementation may also reduce miscarriage rates.</p> <p>Methods</p> <p>We retroactively compared, utilizing two independent statistical models, miscarriage rates in 73 DHEA supplemented pregnancies at two independent North American infertility centers, age-stratified, to miscarriages reported in a national U.S. in vitro fertilization (IVF) data base.</p> <p>Results</p> <p>After DHEA supplementation the miscarriage rate at both centers was 15.1% (15.0% and 15.2%, respectively). For DHEA supplementation Mantel-Hänszel common odds ratio (and 95% confidence interval), stratified by age, was significantly lower, relative to odds of miscarriage in the general IVF control population [0.49 (0.25-0.94; p = 0.04)]. Miscarriage rates after DHEA were significantly lower at all ages but most pronounced above age 35 years.</p> <p>Discussion</p> <p>Since DOR patients in the literature are reported to experience significantly higher miscarriage rates than average IVF patients, the here observed reduction in miscarriages after DHEA supplementation exceeds, however, all expectations. Miscarriage rates after DHEA not only were lower than in an average national IVF population but were comparable to rates reported in normally fertile populations. Low miscarriage rates, comparable to those of normal fertile women, are statistically impossible to achieve in DOR patients without assumption of a DHEA effect on embryo ploidy. Beyond further investigations in infertile populations, these data, therefore, also suggest the investigations of pre-conception DHEA supplementation in normal fertile populations above age 35 years.</p
MTL-CEBPA, a Small Activating RNA Therapeutic Upregulating C/EBP-α, in Patients with Advanced Liver Cancer: A First-in-Human, Multicenter, Open-Label, Phase I Trial.
PURPOSE: Transcription factor C/EBP-α (CCAAT/enhancer-binding protein alpha) acts as a master regulator of hepatic and myeloid functions and multiple oncogenic processes. MTL-CEBPA is a first-in-class small activating RNA oligonucleotide drug that upregulates C/EBP-α. PATIENTS AND METHODS: We conducted a phase I, open-label, dose-escalation trial of MTL-CEBPA in adults with advanced hepatocellular carcinoma (HCC) with cirrhosis, or resulting from nonalcoholic steatohepatitis or with liver metastases. Patients received intravenous MTL-CEBPA once a week for 3 weeks followed by a rest period of 1 week per treatment cycle in the dose-escalation phase (3+3 design). RESULTS: Thirty-eight participants have been treated across six dose levels (28-160 mg/m2) and three dosing schedules. Thirty-four patients were evaluable for safety endpoints at 28 days. MTL-CEBPA treatment-related adverse events were not associated with dose, and no maximum dose was reached across the three schedules evaluated. Grade 3 treatment-related adverse events occurred in nine (24%) patients. In 24 patients with HCC evaluable for efficacy, an objective tumor response was achieved in one patient [4%; partial response (PR) for over 2 years] and stable disease (SD) in 12 (50%). After discontinuation of MTL-CEBPA, seven patients were treated with tyrosine kinase inhibitors (TKIs); three patients had a complete response with one further PR and two with SD. CONCLUSIONS: MTL-CEBPA is the first saRNA in clinical trials and demonstrates an acceptable safety profile and potential synergistic efficacy with TKIs in HCC. These encouraging phase I data validate targeting of C/EBP-α and have prompted MTL-CEBPA + sorafenib combination studies in HCC
CfA4: Light Curves for 94 Type Ia Supernovae
We present multi-band optical photometry of 94 spectroscopically-confirmed
Type Ia supernovae (SN Ia) in the redshift range 0.0055 to 0.073, obtained
between 2006 and 2011. There are a total of 5522 light curve points. We show
that our natural system SN photometry has a precision of roughly 0.03 mag or
better in BVr'i', 0.06 mag in u', and 0.07 mag in U for points brighter than
17.5 mag and estimate that it has a systematic uncertainty of 0.014, 0.010,
0.012, 0.014, 0.046, and 0.073 mag in BVr'i'u'U, respectively. Comparisons of
our standard system photometry with published SN Ia light curves and comparison
stars reveal mean agreement across samples in the range of ~0.00-0.03 mag. We
discuss the recent measurements of our telescope-plus-detector throughput by
direct monochromatic illumination by Cramer et al (in prep.). This technique
measures the whole optical path through the telescope, auxiliary optics,
filters, and detector under the same conditions used to make SN measurements.
Extremely well-characterized natural-system passbands (both in wavelength and
over time) are crucial for the next generation of SN Ia photometry to reach the
0.01 mag accuracy level. The current sample of low-z SN Ia is now sufficiently
large to remove most of the statistical sampling error from the dark energy
error budget. But pursuing the dark-energy systematic errors by determining
highly-accurate detector passbands, combining optical and near-infrared (NIR)
photometry and spectra, using the nearby sample to illuminate the population
properties of SN Ia, and measuring the local departures from the Hubble flow
will benefit from larger, carefully measured nearby samples.Comment: 43 page
A mini-review on the development of Si-based thin film anodes for Li-ion batteries
This review provides a summary of the progress in research on various Si-based thin films as anode
materials for lithium-ion batteries. The lithiation mechanism models, different types of materials from
pure monolithic Si thin film to Si-based three-dimensional structured composite thin films, the effect of
liquid and solid-state electrolytes on the performance of Si were considered and various available
preparation techniques were discussed. A table summarizing important information on such systems
including the thin film features, preparation methods and conditions, electrochemical test conditions
and obtained results in order to elucidate the approaches used to prepare a stable thin film anode with
high capacity and long cycle life is provided. We believe that this review will help the researchers to find
some answers and induce some new ideas
Genome-wide Analyses Identify KIF5A as a Novel ALS Gene
To identify novel genes associated with ALS, we undertook two lines of investigation. We carried out a genome-wide association study comparing 20,806 ALS cases and 59,804 controls. Independently, we performed a rare variant burden analysis comparing 1,138 index familial ALS cases and 19,494 controls. Through both approaches, we identified kinesin family member 5A (KIF5A) as a novel gene associated with ALS. Interestingly, mutations predominantly in the N-terminal motor domain of KIF5A are causative for two neurodegenerative diseases: hereditary spastic paraplegia (SPG10) and Charcot-Marie-Tooth type 2 (CMT2). In contrast, ALS-associated mutations are primarily located at the C-terminal cargo-binding tail domain and patients harboring loss-of-function mutations displayed an extended survival relative to typical ALS cases. Taken together, these results broaden the phenotype spectrum resulting from mutations in KIF5A and strengthen the role of cytoskeletal defects in the pathogenesis of ALS.Peer reviewe
TNOs are Cool: A Survey of the Trans-Neptunian Region: Radiometric properties of Trans-Neptunian Objects
The "TNOs are Cool: A Survey of the Trans-Neptunian Region" project is a Herschel Open Time Key Program awarded some 370 h of Herschel observing time. The observations include PACS and SPIRE point-source photometry on about 140 trans-Neptunian objects with known orbits. The goal is to characterize the individual objects and the full sample using radiometric techniques, in order to probe formation and evolution processes in the Solar System and to establish a benchmark for understanding the Solar System debris disk as well as extra-solar ones. We present results on a set of TNOs which were selected for the Science Demonstration and early mission phases and report on progress in deriving effective sizes, geometric albedos, and thermal characteristics. Our early sample also includes binary objects for which density estimates can be made on the basis of the derived diameters. TNO densities can provide insight into Solar-System formation scenarios
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