9,791 research outputs found
The aeronomy of vibrationally excited ozone
Theoretical calculations show that above 80 km in the earth's atmosphere the production of vibrationally excited ozone by chemical processes leads to number densities which are usually larger than those expected for local thermodynamic equilibrium. Quenching of highly excited molecules produced in O+O2+M, O3+M provided a significant source of the lower lying states above the mesopause while the 9.6 microns emission of O3 (0,0,1) was a major sink. Analysis of available laboratory results implied that reactions involving excited ozone play a significant role in the global ozone balance despite the relatively small abundance of the molecule. However, this effect is implicit in many of the rate coefficients currently used in stratospheric calculations. In the upper mesosphere and lower thermosphere, where the excited state populations differ from those for thermal equilibrium, published reaction rate data are not necessarily applicable to aeronomic calculations
Impaired Nuclear Export of Polyglutamine-Expanded Androgen Receptor in Spinal and Bulbar Muscular Atrophy.
Spinal and bulbar muscular atrophy (SBMA) is a neuromuscular disease caused by polyglutamine (polyQ) expansion in the androgen receptor (AR). Prior studies have highlighted the importance of AR nuclear localization in SBMA pathogenesis; therefore, in this study, we sought to determine the role of AR nuclear export in the pathological manifestations of SBMA. We demonstrate here that the nuclear export of polyQ-expanded AR is impaired, even prior to the formation of intranuclear inclusions of aggregated AR. Additionally, we find that promoting AR export with an exogenous nuclear export signal substantially reduces its aggregation and blocks hormone-induced toxicity. Moreover, we show that these protective effects are conferred by destabilization of the mutant protein due to an increase in proteasomal degradation of the cytoplasmic AR. Despite a growing body of evidence that global disruption of nucleo/cytoplasmic transport occurs in ALS and HD, our data suggest that no such global disruption occurs in models of SBMA; rather, AR-specific mechanisms, including reduced phosphorylation at Serine 650, are likely responsible for the impaired nuclear export of polyQ-expanded AR
Public health and the economy could be served by reallocating medical expenditures to social programs.
As much as 30% of US health care spending in the United States does not improve individual or population health. To a large extent this excess spending results from prices that are too high and from administrative waste. In the public sector, and particularly at the state level, where budget constraints are severe and reluctance to raise taxes high, this spending crowds out social, educational, and public-health investments. Over time, as spending on medical care increases, spending on improvements to the social determinants of health are starved. In California the fraction of General Fund expenditures spent on public health and social programs fell from 34.8% in fiscal year 1990 to 21.4% in fiscal year 2014, while health care increased from 14.1% to 21.3%. In spending more on healthcare and less on other efforts to improve health and health determinants, the state is missing important opportunities for health-promoting interventions with a strong financial return. Reallocating ineffective medical expenditures to proven and cost-effective public health and social programs would not be easy, but recognizing its potential for improving the public's health while saving taxpayers billions of dollars might provide political cover to those willing to engage in genuine reform. National estimates of the percent of medical spending that does not improve health suggest that approximately $5 billion of California's public budget for medical spending has no positive effect on health. Up to 10,500 premature deaths could be prevented annually by reallocating this portion of medical spending to public health. Alternatively, the same expenditure could help an additional 418,000 high school students to graduate
A technique for determining daytime atmospheric oxide above 50 km from backscattered ultraviolet measurements
Airglow from gamma band resonance fluorescence of nitric oxide near 255 nm is calculated at several solar zenith angles. Data from the Nimbus 4 BUV wavelengths 273.5 to 287.6 nm is used to estimate the Rayleigh and ozone scattering contributions to the BUV 255.5 nm data and the remaining signal is attributed to NO airglow. The low solar zenith angle contributions by NO is less than 0.5%, and the high latitude/high zenith angle contribution exceeds 5%. This technique allows for estimating NO content above 50 km, as well as partitioning that content between the mesosphere and thermosphere
Ohio\u27s Long Arm Statute
The 106th General Assembly of the Ohio Legislature, in response to the necessity of keeping abreast with modern society and the vastly increased mobility of its members, enacted into law Sections 2307.381 to 2307.385 inclusive, of the Ohio Revised Code. Collectively these sections are popularly known as the long-arm statute.The purpose of this note is to attempt to estimate the extent to which Ohio will utilize the statute, based on the experience of other states having case law on the subject, since there has been no litigation as yet under the statute in Ohio. Discussion is basically limited to the questions of transacting business and of tortious conduct, as these are the most frequently litigated facets of such statutes
Designing Dental Student Portfolios to Assess Performance
The purpose of this poster is to share a project developed by Marquette University’s liaisons to the American Dental Education Association’s Commission on Change and Innovation in Dental Education with others interested in learning about the use of portfolios to assess the quality of student performance in dental school. Sample components from the pilot portfolios will be integrated into the poster to provide participants with a view from portfolio design to completion. Portfolios are becoming a more common method of assessing the quality of student performance in health professions education. Portfolios can assist in documenting evidence of specific competencies at the student level and also serve as a longitudinal measure of a student’s development
In‐situ measurements of nitric oxide in the high latitude upper stratosphere
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95623/1/grl2950.pd
Optimal control of a process with discrete and continuous decision variables
technical reportThe task of dynamic optimization consists of manipulating the inputs to a dynamic system (i.e., one in which the state varies with time) so that the system performs in an advantageous manner. This paper presents a systematic technique for solving the problem of optimally controlling a converter aisle in a copper smelter. The converter aisle is distinguished from the usual dynamic system in that some of the control variables occur as discrete decisions while others may vary continuously with time. In this sense, the converter aisle typifies many industrial processes. The aisle is viewed as a total system with the objective of optimizing overall performance as evaluated using a mathematical performance criterion. Typical criteria reflect total processing time and operating costs. An essential step towards optimization is the development of a mathematical model to predict the state of the system. a simple mathematical model of the converter aisle is developed and using this model, two optimization approaches are examined: direct optimization of the total system and partitioning the system into interacting subproblems. The partitioned approach is pursued in detail with techniques for solving the optimization subprobelms presented and illustrated by numerical examples
Absence of manganese superoxide dismutase delays p53-induced tumor formation.
BACKGROUND: Manganese superoxide dismutase (MnSOD) is a mitochondrial antioxidant enzyme that is down-regulated in a majority of cancers. Due to this observation, as well as MnSOD\u27s potent antioxidant enzymatic activity, MnSOD has been suggested as a tumor suppressor for over 30 years. However, testing this postulate has proven difficult due to the early post-natal lethality of the MnSOD constitutive knock-out mouse. We have previously used a conditional tissue-specific MnSOD knock-out mouse to study the effects of MnSOD loss on the development of various cell types, but long-term cancer development studies have not been performed. We hypothesized the complete loss of MnSOD would significantly increase the rate of tumor formation in a tissue-specific manner.
RESULTS: Utilizing a hematopoietic stem cell specific Cre-recombinase mouse model, we created pan-hematopoietic cell MnSOD knock-out mice. Additionally, we combined this MnSOD knock-out with two well established models of lymphoma development: B-lymphocyte specific Myc over-expression and conditional pan-hematopoietic cell p53 knock-out. Mice were allowed to age unchallenged until illness or death had occurred. Contrary to our initial hypothesis, the loss of MnSOD alone was insufficient in causing an increase in tumor formation, but did cause significant life-shortening skin pathology in a strain-dependent manner. Moreover, the loss of MnSOD in conjunction with either Myc overexpression or p53 knock-out did not accelerate tumor formation, and in fact delayed lymphomagenesis in the p53 knock-out model.
CONCLUSIONS: Our findings strongly suggest that MnSOD does not act as a classical tumor suppressor in hematological tissues. Additionally, the complete loss of MnSOD may actually protect from tumor development by the creation of an unfavorable redox environment for tumor progression. In summary, these results in combination with our previous work suggest that MnSOD needs to be tightly regulated for proper cellular homeostasis, and altering the activity in either direction may lead to cellular dysfunction, oncogenesis, or death
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