971 research outputs found

    Water on Oxide Surfaces

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    Most oxidE.. surfaces interact with ambient water vapor to form a layer of chemisorbed hydroxyls. Physical adsorption of multilayer water readily starts by hydrogen bonding onto the hydroxyl array. The normally hydrophilic surface 0ÂŁ silica can be modified by heating to produce a predominantly hydrophobic matrix which contains but a few isolated hydrophilic sites, around which water adsorbs in clusters. The authors\u27 results on both hydrophilic and hydrophobed oxides are discussed and compared to results in the literature

    Water on Oxide Surfaces

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    Most oxidE.. surfaces interact with ambient water vapor to form a layer of chemisorbed hydroxyls. Physical adsorption of multilayer water readily starts by hydrogen bonding onto the hydroxyl array. The normally hydrophilic surface 0ÂŁ silica can be modified by heating to produce a predominantly hydrophobic matrix which contains but a few isolated hydrophilic sites, around which water adsorbs in clusters. The authors\u27 results on both hydrophilic and hydrophobed oxides are discussed and compared to results in the literature

    Factors Promoting or Preventing Caregivers from Allowing Pediatric Participation in Research

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    Introduction The likelihood of a child participating in a clinical trial is mostly independent of the child’s willingness to participate; children’s lack of autonomy obliges parental involvement, which is concurrently conditional to parental understanding, trust and endorsement of the research study. Objectives To identify potential predictors for allowing children to participate in clinical studies and to evaluate if motivators that promote or prevent parental support of children to participate in clinical studies differed according to racial/ethnic categorization. Methods A stratified sample of 1,057 caregivers of children 1-18 years old who in 2015 resided in South Florida’s Miami-Dade, Broward, and Palm Beach counties were included in the study. Pediatric research participation was analyzed by exploratory unadjusted weighted multinomial association tests. Results There were different reasons for which caregivers will allow or reject children participation in clinical research. The sex of the respondent [OR = 2.48 (1.58 - 3.90)], difficulties accessing health care access [OR = 2.77 (1.60 – 4.80)], and child’s underweight status [OR: 3.22 (1.90 – 5.47)] significantly differed between those very likely and unlikely to participate. Conclusions Caregivers decision to allow children to participate or not in clinical research differ according to race/ethnic classification, gender of caregivers, and weight status of the child

    Resolvin E1 Reverses Experimental Periodontitis and Dysbiosis

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    Periodontitis is a biofilm-induced inflammatory disease characterized by dysbiosis of the commensal periodontal microbiota. It is unclear how natural regulation of inflammation affects the periodontal biofilm. Promoters of active resolution of inflammation including Resolvin E1 (RvE1) effectively treat inflammatory periodontitis in animal models. The goals of this study were 1) to compare periodontal tissue gene expression in different clinical conditions, 2) to determine the impact of local inflammation on the composition of subgingival bacteria, and 3) to understand how inflammation impacts these changes. Two clinically-relevant experiments were performed in rats: prevention and treatment of ligature-induced periodontitis with RvE1 topical treatment. The gingival transcriptome was evaluated by RNA-seq sequencing of mRNA. The composition of the subgingival microbiota was characterized by 16S rDNA sequencing. Periodontitis was assessed by bone morphometric measurements and histomorphometry of block sections. H&E and, tartrate resistant acid phosphatase staining were used to characterize and quantify inflammatory changes. RvE1 treatment prevented bone loss in ligature induced periodontitis. Osteoclast density and inflammatory cell infiltration in the RvE1 groups were lower than those in the placebo group. RvE1 treatment reduced expression of inflammation-related genes returning the expression profile to one more similar to health. Treatment of established periodontitis with RvE1 reversed bone loss, reversed inflammatory gene expression and reduced osteoclast density. Assessment of the rat subgingival microbiota after RvE1 treatment revealed marked changes in both prevention and treatment experiments. The data suggest that modulation of local inflammation has a major role in shaping the composition of the subgingival microbiota

    Using Near Infrared Reflectance Spectroscopy (NIRS) to predict the protein and energy digestibility of lupin kernel meals when fed to rainbow trout, Oncorhynchus mykiss

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    This study examined the potential of using near infrared spectroscopy (NIRS) to predict the nutrient composition, energy density and the digestible protein and digestible energy values of lupin kernel meals when fed to rainbow trout. A series of 136 lupin kernel meals were assessed for their protein and energy digestibilities using the diet-substitution approach in a series of 10 experiments over a 6-year period from 2002 to 2008. Two reference diets were also included in each experiment. Minimal variance in the digestibility parameters of both reference diets was observed among the experiments ensuring that there was a high degree of robustness in the across-experiment evaluations. The same lupin kernel meal samples were also scanned using a diode array near infrared spectrophotometer (DA-NIRS). The spectra obtained by the DA-NIRS were chemometrically calibrated against both the chemical composition and the digestible value data using multivariate analysis software. The cross validation tests used in this study provide a valid indication of the potential to predict the nutrient composition, energy value and digestible protein and energy values of the lupin kernel meals as used in diets for rainbow trout. That the standard errors of cross validation (SECV) of the parameters investigated were generally commensurate with the cross trial variation seen in the reference sample indicating robust calibrations for the two target parameters of digestible protein and digestible energy. Therefore this study demonstrates that within one raw material type that not only does significant variability in the digestible value of the raw materials exist, but that it is possible to use NIRS technology to provide rapid estimates of the digestible value of those raw materials in near real-time. © 2014 John Wiley & Sons Ltd

    Managing healthcare budgets in times of austerity: the role of program budgeting and marginal analysis

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    Given limited resources, priority setting or choice making will remain a reality at all levels of publicly funded healthcare across countries for many years to come. The pressures may well be even more acute as the impact of the economic crisis of 2008 continues to play out but, even as economies begin to turn around, resources within healthcare will be limited, thus some form of rationing will be required. Over the last few decades, research on healthcare priority setting has focused on methods of implementation as well as on the development of approaches related to fairness and legitimacy and on more technical aspects of decision making including the use of multi-criteria decision analysis. Recently, research has led to better understanding of evaluating priority setting activity including defining ‘success’ and articulating key elements for high performance. This body of research, however, often goes untapped by those charged with making challenging decisions and as such, in line with prevailing public sector incentives, decisions are often reliant on historical allocation patterns and/or political negotiation. These archaic and ineffective approaches not only lead to poor decisions in terms of value for money but further do not reflect basic ethical conditions that can lead to fairness in the decision-making process. The purpose of this paper is to outline a comprehensive approach to priority setting and resource allocation that has been used in different contexts across countries. This will provide decision makers with a single point of access for a basic understanding of relevant tools when faced with having to make difficult decisions about what healthcare services to fund and what not to fund. The paper also addresses several key issues related to priority setting including how health technology assessments can be used, how performance can be improved at a practical level, and what ongoing resource management practice should look like. In terms of future research, one of the most important areas of priority setting that needs further attention is how best to engage public members

    Increased metabolic rate of hauled-out harbor seals (Phoca vitulina) during the molt

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    Harbor seals (Phoca vitulina) live in cold temperate or polar seas and molt annually, renewing their fur over a period of approximately four weeks. Epidermal processes at this time require a warm skin and therefore to avoid an excessive energy cost at sea during the molt, harbour seals and many other pinnipeds increase the proportion of time hauled out on land. We predicted that metabolic rate during haulout would be greater during the molt to sustain an elevated skin temperature in order to optimize skin and hair growth. To examine this, we measured post-haulout oxygen consumption (V̇O2) in captive harbor seals during molt and post-molt periods. We recorded greater V̇O2 of seals while molting than when the molt was complete. Post-haulout V̇O2 increased faster and reached a greater maximum at 40 minutes during the molt. Thereafter, V̇O2 decreased but still remained greater suggesting that while metabolic rate was relatively high throughout haulouts, it was most pronounced in the first 40 minutes. Air temperature, estimated heat increment of feeding (eHIF) and mass also explained 15.5% of V̇O2 variation over 180 minutes post-haulout, suggesting that the environment, feeding state and body size influenced the metabolic rate of individual animals. These results show that moulting seals have greater metabolic rates when hauled out, especially during the early stages of the haulout period. As a consequence, human disturbance that changes the haulout behaviour of molting seals will increase their energy costs and potentially extend the duration of the molt

    TNF-α induced endothelial MAdCAM-1 expression is regulated by exogenous, not endogenous nitric oxide

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    BACKGROUND: MAdCAM-1 is an adhesion molecule expressed in Peyer's patches and lymphoid tissues which is mobilized by cytokines like TNF-α and is a major determinant of lymphocyte trafficking to the gut in human inflammatory bowel disease (IBD). It has been suggested that both reactive oxygen and nitrogen metabolites participate in regulating adhesion molecule expression in response to TNF-α. METHODS: To examine how exogenous and endogenous sources of NO modulate MAdCAM-1 induction by TNF-α, we pre-treated mouse lymphatic endothelial cells with either long or short acting NO donors prior to TNF-α-stimulation, and measured MAdCAM-1 induction at 24 h. RESULTS AND DISCUSSION: DETA-NO, a long-acting NO donor, and SperNO, a rapid releasing NO donor both inhibited TNF-α-stimulated MAdCAM-1 expression in a concentration dependent manner. Both NO donors also reduced a4b7-dependent lymphocyte endothelial adhesion. Inhibition of endogenous NO production by either L-NAME, a non-selective NOS inhibitor, or by 1400 w, a selective iNOS inhibitor failed to induce, or potentiate TNF-α regulated MAdCAM-1 expression. CONCLUSIONS: Exogenous NO donors may be beneficial in the treatment of IBD, while endogenous nitric oxide synthases may be less effective in controlling adhesion molecule expression in response to cytokines

    What caused terrestrial dust loading and climate downturns between A.D. 533 and 540?

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    Sn-rich particles, Ni-rich particles, and cosmic spherules are found together at four discrete stratigraphic levels within the 362-360 m depth interval of the Greenland Ice Sheet Project 2 (GISP2) ice core (72.6°N, 38.5°W, elevation: 3203 m). Using a previously derived calendar-year time scale, these particles span a time of increased dust loading of Earth's atmosphere between A.D. 533 and 540. The Sn-rich and Ni-rich particles contain an average of 10–11 wt% C. Their high C contents coupled with local enrichments in the volatile elements I, Zn, Cu, and Xe suggest a cometary source for the dust. The late spring timing of extraterrestrial input best matches the Eta Aquarid meteor shower associated with comet 1P/Halley. An increased flux of cometary dust might explain a modest climate downturn in A.D. 533. Both cometary dust and volcanic sulfate probably contributed to the profound global dimming during A.D. 536 and 537 but may be insufficient sources of fine aerosols. We found tropical marine microfossils and aerosol-sized CaCO3 particles at the end A.D. 535–start A.D. 536 level that we attribute to a low-latitude explosion in the ocean. This additional source of dust is probably needed to explain the solar dimming during A.D. 536 and 537. Although there has been no extinction documented at A.D. 536, our results are relevant because mass extinctions may also have multiple drivers. Detailed examinations of fine particles at and near extinction horizons can help to determine the relative contributions of cosmic and volcanic drivers to mass extinctions

    Menstruation as a Weapon of War – The Politics of the Bleeding Body for Women on Political Protest at Armagh Prison Northern Ireland.

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    This article draws on the voices of women political prisoners who were detained at Armagh Prison during the period of the Troubles or the Conflict in Northern Ireland. It focuses on women who undertook an extraordinary form of protest against the prison authorities during the 1980s, known as the No Wash Protest. As the prisoners were prevented from leaving their cells by prison officer either to wash or to use the toilet, the women, living in the midst of their own dirt and body waste, added menstrual blood as a form of protest
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