How does the relaxation of a supercooled liquid depend on its microscopic dynamics?

Using molecular dynamics computer simulations we investigate how the relaxation dynamics of a simple supercooled liquid with Newtonian dynamics differs from the one with a stochastic dynamics. We find that, apart from the early beta-relaxation regime, the two dynamics give rise to the same relaxation behavior. The increase of the relaxation times of the system upon cooling, the details of the alpha-relaxation, as well as the wave vector dependence of the Edwards-Anderson-parameters are independent of the microscopic dynamics.Comment: 6 pages of Latex, 4 figure

Evaluation and Use of an Index of Oral Health Status

Objectives: The goals of this investigation were (1) to evaluate the Oral Health Status Index in relation to demographic characteristics, socioeconomic status, and preventive behaviors of an adult population; and (2) to understand how individual index components performed as indicators of oral health status compared to the composite index. Methods : The Oral Health Status Index (OHSI) was used on a probability sample of adults, aged 18–93 years, living in the Detroit tricounty area. Data were collected on 509 subjects via in-home dental examinations. Bivariate and multivariate analyses were used to compare the OHSI and its components, including decayed, missing, and replaced teeth, free ends, and moderate and severe periodontal disease measures. Results : The mean OHSI score for subjects was 77.3 (se=1.83) with a range of -8.0 to 100.0. In regression analyses, OHSI scores were positively correlated with subjects' education level, self-rated oral health scores, and frequency of dental checkups and negatively correlated with age, nonwhite race, and smoking. Of the index components, missing teeth performed well as an indicator of oral health status. Missing teeth were positively correlated with age, nonwhite race, and smoking and negatively correlated with education level, self-rated oral health, and use of Medicaid. About 53 percent of variance in OHSI scores was explained by the multivariate models, compared to 46 percent for missing teeth. Conclusions : Choosing an indicator of oral health status likely will depend upon the characteristics of the population to be studied. As a composite measure of oral health status, the OHSI performed acceptably; however, missing teeth, an index component, also worked well. Continued evaluation of the OHSI is warranted.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65652/1/j.1752-7325.1997.tb02980.x.pd

Lung volume reduction surgery combined with cardiac interventions

Objective: Postoperative course and functional outcome were evaluated in patients who underwent lung volume reduction surgery (LVRS) or in combination with valve replacement (VR), percutaneous transluminal coronary angioplasty (PTCA), placement of a stent, or coronary artery bypass grafting (CABG). Methods: Patients with severe bronchial obstruction and hyperinflation due to pulmonary emphysema were evaluated for lung volume reduction surgery. Cardiac disorders were screened by history and physical examination and assessed by coronary angiography. Nine patients were accepted for LVRS in combination with an intervention for coronary artery disease (CAD). In addition, three patients with valve disease and severe emphysema were accepted for valve replacement (two aortic-, one mitral valve) only in combination with LVRS. Functional results over the first 6 months were analysed. Results: Pulmonary function testing demonstrates a significant improvement in postoperative FEV1 in patients who underwent LVRS combined with an intervention for CAD. This was reflected in reduction of overinflation (residual volume/total lung capacity (RV/TLC)), and improvement in the 12-min walking distance and dyspnea. Median hospital stay was 15 days (10-33). One patient in the CAD group died due to pulmonary edema on day 2 postoperatively. One of the three patients who underwent valve replacement and LVRS died on day 14 postoperatively following intestinal infarction. Both survivors improved in pulmonary function, dyspnea score and exercise capacity. Complications in all 12 patients included pneumothorax (n = 2), hematothorax (n = 1) and urosepsis (n = 1). Conclusion: Functional improvement after LVRS in patients with CAD is equal to patients without CAD. Mortality in patients who underwent LVRS after PTCA or CABG was comparable to patients without CAD. LVRS enables valve replacement in selected patients with severe emphysema otherwise inoperabl

Deployment of the northern fish cage and mooring, University of New Hampshire — Open Ocean Aquaculture Program summer 2000

The University of New Hampshire - Open Ocean Aquaculture (UNH-OOA) program has worked for the past few years on developing the technology to deploy and maintain fish cages in open, exposed northern waters. In June 1999, two Sea Station octagonal net cages by Ocean Spar Technologies were deployed with their UNH designed and constructed moorings. In June 2000 the Northern Cage and its mooring were retrieved, examined and repaired , and readied for redeployment. This was a complex operation, initiated by a team of UNH ocean engineers lead by Dr. Barbaros Celikkol. This year's effort was expanded with the addition of a Program Manager (Michael Chambers), the Fishing Vessel Nobska, and researchers from the Woods Hole Oceanographic Institution (WHOI). During the week of 21 to 25 August 2000, the cage and mooring were assembled and deployed at the UNH-OOA site seven miles offshore the New Hampshire coast, south of the Isle of Shoals. This collaborative effort involved members of the UNH Mechanical Engineering Dept., UNH divers, members of the WHOI Applied Ocean Physics & Engineering Dept. and the Captain and crew of the FV Nobska. Ship support for the deployment was provided by the R/V Gulf Challenger and Galen J. (UNH) and the FV Nobska (a 100 foot fishing vessel based at Woods Hole, MA). The work was favored by light wind and sea conditions. The endeavor resulted in the successful placement of the North Cage and its complex mooring system with load cells and environmental sensors. Unexpected and unexplained tangling of the mooring system, in particular near its grid corner points, was encountered and corrected.Fudning was provided by the National Oceanic and Atmospheric Adminstration for the Open Ocean Aquaculture Project under Contract No. NA86RG0016 to the Univesity of New Hampshire and under Subcontracts 00-394 and 01-442 to the Woods Hole Oceanographic Institution

Educating Dentists about Fissure Sealants: Effects on Knowledge, Attitudes, and Use

This study evaluated the effects of three modes of education on dentists' knowledge, attitudes, and use of pit and fissure sealants. A randomly selected group of dentists was invited to participate in a sealant education initiative. During a 12-month period, a total of 662 dentists either (1) attended continuing education courses, (2) received written materials and videotapes by mail, or (3) received only written materials by mail. A comparison group (n=337) received no materials until after the education phase and evaluation had been completed. Pre-and postintervention surveys were used to measure changes in knowledge, attitudes, and sealant use. Response rates to the two surveys were 62 percent and 76 percent, respectively. Preintervention values for knowledge scores, an attitude scale, and sealant use were similar among the four groups. At followup, the three education groups had significantly higher knowledge scores than the comparison group. Attitude values for all but one group were not significantly different, and sealant use by all groups was identical. The numbers of respondents not using sealants declined slightly between surveys in the three education groups while rising slightly in the No-Education Group. Because program outcomes were similar to those of another sealant initiative, it can probably be concluded that continuing education will increase dentists' knowledge about sealants, but have little effect upon their attitudes or their use of the technique. The changes observed in this investigation maybe due to the particular capacity for cognitive and affective change's of participants, characteristics of the technology being promoted, and external forces in the professional environment.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66125/1/j.1752-7325.1991.tb02208.x.pd

Vitamins and Perinatal Outcomes Among HIV-Negative Women in Tanzania.

Prematurity and low birth weight are associated with high perinatal and infant mortality, especially in developing countries. Maternal micronutrient deficiencies may contribute to these adverse outcomes. In a double-blind trial in Dar es Salaam, Tanzania, we randomly assigned 8468 pregnant women (gestational age of fetus, 12 to 27 weeks) who were negative for human immunodeficiency virus infection to receive daily multivitamins (including multiples of the recommended dietary allowance) or placebo. All the women received prenatal supplemental iron and folic acid. The primary outcomes were low birth weight (<2500 g), prematurity, and fetal death. The incidence of low birth weight was 7.8% among the infants in the multivitamin group and 9.4% among those in the placebo group (relative risk, 0.82; 95% confidence interval [CI], 0.70 to 0.95; P=0.01). The mean difference in birth weight between the groups was modest (67 g, P<0.001). The rates of prematurity were 16.9% in the multivitamin group and 16.7% in the placebo group (relative risk, 1.01; 95% CI, 0.91 to 1.11; P=0.87), and the rates of fetal death were 4.3% and 5.0%, respectively (relative risk, 0.87; 95% CI, 0.72 to 1.05; P=0.15). Supplementation reduced both the risk of a birth size that was small for gestational age (<10th percentile; 10.7% in the multivitamin group vs. 13.6% in the placebo group; relative risk, 0.77; 95% CI, 0.68 to 0.87; P<0.001) and the risk of maternal anemia (hemoglobin level, <11 g per deciliter; relative risk, 0.88; 95% CI, 0.80 to 0.97; P=0.01), although the difference in the mean hemoglobin levels between the groups was small (0.2 g per deciliter, P<0.001). Multivitamin supplementation reduced the incidence of low birth weight and small-for-gestational-age births but had no significant effects on prematurity or fetal death. Multivitamins should be considered for all pregnant women in developing countries. (ClinicalTrials.gov number, NCT00197548 [ClinicalTrials.gov].)

Disrupting the Repeat Domain of Premelanosome Protein (PMEL) Produces Dysamyloidosis and Dystrophic Ocular Pigment Reflective of Pigmentary Glaucoma

Pigmentary glaucoma has recently been associated with missense mutations in PMEL that are dominantly inherited and enriched in the protein’s fascinating repeat domain. PMEL pathobiology is intriguing because PMEL forms functional amyloid in healthy eyes, and this PMEL amyloid acts to scaffold melanin deposition. This is an informative contradistinction to prominent neurodegenerative diseases where amyloid formation is neurotoxic and mutations cause a toxic gain of function called “amyloidosis”. Preclinical animal models have failed to model this PMEL “dysamyloidosis” pathomechanism and instead cause recessively inherited ocular pigment defects via PMEL loss of function; they have not addressed the consequences of disrupting PMEL’s repetitive region. Here, we use CRISPR to engineer a small in-frame mutation in the zebrafish homolog of PMEL that is predicted to subtly disrupt the protein’s repetitive region. Homozygous mutant larvae displayed pigmentation phenotypes and altered eye morphogenesis similar to presumptive null larvae. Heterozygous mutants had disrupted eye morphogenesis and disrupted pigment deposition in their retinal melanosomes. The deficits in the pigment deposition of these young adult fish were not accompanied by any detectable glaucomatous changes in intraocular pressure or retinal morphology. Overall, the data provide important in vivo validation that subtle PMEL mutations can cause a dominantly inherited pigment pathology that aligns with the inheritance of pigmentary glaucoma patient pedigrees. These in vivo observations help to resolve controversy regarding the necessity of PMEL’s repeat domain in pigmentation. The data foster an ongoing interest in an antithetical dysamyloidosis mechanism that, akin to the amyloidosis of devastating dementias, manifests as a slow progressive neurodegenerative disease

Climate risk management for water in semi-arid regions

Background: New sources of hydroclimate information based on forecast models and observational data have the potential to greatly improve the management of water resources in semi-arid regions prone to drought. Better management of climate-related risks and opportunities requires both new methods to develop forecasts of drought indicators and river flow, as well as better strategies to incorporate these forecasts into drought, river or reservoir management systems. In each case the existing institutional and policy context is key, making a collaborative approach involving stakeholders essential. Methods: This paper describes work done at the IRI over the past decade to develop statistical hydrologic forecast and water allocation models for the semi arid regions of NE Brazil (the “Nordeste”) and central northern Chile based on seasonal climate forecasts. Results: In both locations, downscaled precipitation forecasts based on lagged SST predictors or GCM precipitation forecasts exhibit quite high skill. Spring-summer melt flow in Chile is shown to be highly predictable based on estimates of previous winter precipitation, and moderately predictable up to 6 months in advance using climate forecasts. Retrospective streamflow forecasts here are quite effective in predicting reductions in water rights during dry years. For the multi-use Oros reservoir in NE Brazil, streamflow forecasts have the most potential to optimize water allocations during multi-year low-flow periods, while the potential is higher for smaller reservoirs, relative to demand. Conclusions: This work demonstrates the potential value of seasonal climate forecasting as an integral part of drought early warning and for water allocation decision support systems in semi-arid regions. As human demands for water rise over time this potential is certain to rise in the future