762 research outputs found
âEquality and Privacy by Designâ: A New Model of Artificial Intelligence Data Transparency via Auditing, Certification, and Safe Harbor Regimes
Maintaining the Union of Unit Discs Under Insertions with Near-Optimal Overhead
We present efficient data structures for problems on unit discs and arcs of their boundary in the plane. (i) We give an output-sensitive algorithm for the dynamic maintenance of the union of n unit discs under insertions in O(k log^2 n) update time and O(n) space, where k is the combinatorial complexity of the structural change in the union due to the insertion of the new disc. (ii) As part of the solution of (i) we devise a fully dynamic data structure for the maintenance of lower envelopes of pseudo-lines, which we believe is of independent interest. The structure has O(log^2 n) update time and O(log n) vertical ray shooting query time. To achieve this performance, we devise a new algorithm for finding the intersection between two lower envelopes of pseudo-lines in O(log n) time, using tentative binary search; the lower envelopes are special in that at x=-infty any pseudo-line contributing to the first envelope lies below every pseudo-line contributing to the second envelope. (iii) We also present a dynamic range searching structure for a set of circular arcs of unit radius (not necessarily on the boundary of the union of the corresponding discs), where the ranges are unit discs, with O(n log n) preprocessing time, O(n^{1/2+epsilon} + l) query time and O(log^2 n) amortized update time, where l is the size of the output and for any epsilon>0. The structure requires O(n) storage space
Long-term statin use and psychological well-being
AbstractObjectivesWe sought to study the effect of long-term statin use on psychometric measures in an adult population with underlying coronary artery disease (CAD).BackgroundPrevious studies have suggested associations between cholesterol lowering and psychological well-being.MethodsStudy subjects were recruited from an outpatient cardiology clinic. Psychological well-being was assessed at baseline and annually during follow-up. The exposure of interest was long-term statin use and the outcomes of interest were depression, anxiety, and hostility. We estimated the odds ratios (ORs) and 95% confidence intervals (CI) that represented the strength of association between statin use (vs. no use of any cholesterol-lowering drug) and the risk of having abnormal depression, anxiety, and hostility scores.ResultsStudy subjects had an average follow-up of four years and maximum of seven years. Comparing the 140 patients who had continuous use of statins with the 231 patients who did not use any cholesterol-lowering drugs, statin use was associated with lower risk of abnormal depression scores (OR 0.63, 95% CI 0.43 to 0.93), anxiety (OR 0.69, 95% CI 0.47 to 0.99), and hostility (OR 0.77, 95% CI 0.58 to 0.93) after adjustment for the propensity for statin use and potential confounders. The beneficial psychological effects of the statins appeared to be independent of the drugs' cholesterol-lowering effects.ConclusionsLong-term use of statins among patients with CAD appeared to be associated with reduced risk of anxiety, depression, and hostility
Changes in adenosine receptors during differentiation of 3T3-F442A cells to adipocytes
Tissue-derived proinflammatory effect of adenosine A2B receptor in lung ischemiaâreperfusion injury
ObjectiveIschemiaâreperfusion injury after lung transplantation remains a major source of morbidity and mortality. Adenosine receptors have been implicated in both pro- and anti-inflammatory roles in ischemiaâreperfusion injury. This study tests the hypothesis that the adenosine A2B receptor exacerbates the proinflammatory response to lung ischemiaâreperfusion injury.MethodsAn in vivo left lung hilar clamp model of ischemiaâreperfusion was used in wild-type C57BL6 and adenosine A2B receptor knockout mice, and in chimeras created by bone marrow transplantation between wild-type and adenosine A2B receptor knockout mice. Mice underwent sham surgery or lung ischemiaâreperfusion (1 hour ischemia and 2 hours reperfusion). At the end of reperfusion, lung function was assessed using an isolated buffer-perfused lung system. Lung inflammation was assessed by measuring proinflammatory cytokine levels in bronchoalveolar lavage fluid, and neutrophil infiltration was assessed via myeloperoxidase levels in lung tissue.ResultsCompared with wild-type mice, lungs of adenosine A2B receptor knockout mice were significantly protected after ischemiaâreperfusion, as evidenced by significantly reduced pulmonary artery pressure, increased lung compliance, decreased myeloperoxidase, and reduced proinflammatory cytokine levels (tumor necrosis factor-α; interleukin-6; keratinocyte chemoattractant; regulated on activation, normal T-cell expressed and secreted; and monocyte chemotactic protein-1). Adenosine A2B receptor knockoutâadenosine A2B receptor knockout (donorârecipient) and wild-typeâ adenosine A2B receptor knockout, but not adenosine A2B receptor knockoutâwild-type, chimeras showed significantly improved lung function after ischemiaâreperfusion.ConclusionsThese results suggest that the adenosine A2B receptor plays an important role in mediating lung inflammation after ischemiaâreperfusion by stimulating cytokine production and neutrophil chemotaxis. The proinflammatory effects of adenosine A2B receptor seem to be derived by adenosine A2B receptor activation primarily on resident pulmonary cells and not bone marrow-derived cells. Adenosine A2B receptor may provide a therapeutic target for prevention of ischemiaâreperfusion-related graft dysfunction in lung transplant recipients
PetuniaâĂâhybrida floral scent production is negatively affected by highâtemperature growth conditions
Increasing temperatures due to changing global climate are interfering with plantâpollinator mutualism, an interaction facilitated mainly by floral colour and scent. Gas chromatographyâmass spectroscopy analyses revealed that increasing ambient temperature leads to a decrease in phenylpropanoidâbased floral scent production in two PetuniaâĂâhybrida varieties, P720 and Blue Spark, acclimated at 22/16 or 28/22â°C (day/night). This decrease could be attributed to downâregulation of scentârelated structural gene expression from both phenylpropanoid and shikimate pathways, and upâregulation of a negative regulator of scent production, emission of benzenoids V (EOBV). To test whether the negative effect of increased temperature on scent production can be reduced in flowers with enhanced metabolic flow in the phenylpropanoid pathway, we analysed floral volatile production by transgenic âBlue Sparkâ plants overexpressing CaMV 35Sâdriven Arabidopsis thaliana production of anthocyanin pigments 1 (PAP1) under elevated versus standard temperature conditions. Flowers of 35S:PAP1 transgenic plants produced the same or even higher levels of volatiles when exposed to a longâterm highâtemperature regime. This phenotype was also evident when analysing relevant gene expression as inferred from sequencing the transcriptome of 35S:PAP1 transgenic flowers under the two temperature regimes. Thus, upâregulation of transcription might negate the adverse effects of temperature on scent production.We demonstrate that petunia flowers produce less volatile phenylpropanoid compounds, in both scent bouquets and internal pools, in response to elevated temperatures. We reveal that the decrease in floral scent is correlated with reduced transcript levels of scentârelated genes, and that the adverse effect of high temperature can be negated by expressing transcriptional upâregulators. We believe that the conclusions and implications drawn from the original data presented in our manuscript will be of particular interest to a broad spectrum of your readers, particularly in view of recent changes in global climate and the risk of environmental disruption of plantâpollinator mutualism.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/112003/1/pce12486-sup-0001-si.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/112003/2/pce12486.pd
Post-Mortem diagnosis of dementia by informant interview
Abstract The diagnosis of normal cognition or dementia in the Brazilian Brain Bank of the Aging Brain Study Group (BBBABSG) has relied on postmortem interview with an informant. Objectives: To ascertain the sensitivity and specificity of postmortem diagnosis based on informant interview compared against the diagnosis established at a memory clinic. Methods: A prospective study was conducted at the BBBABSG and at the Reference Center for Cognitive Disorders (RCCD), a specialized memory clinic of the Hospital das ClĂnicas, University of SĂŁo Paulo Medical School. Control subjects and cognitively impaired subjects were referred from the Hospital das ClĂnicas to the RCCD where subjects and their informants were assessed. The same informant was then interviewed at the BBBABSG. Specialists' panel consensus, in each group, determined the final diagnosis of the case, blind to other center's diagnosis. Data was compared for frequency of diagnostic equivalence. For this study, the diagnosis established at the RCCD was accepted as the gold standard. Sensitivity and specificity were computed. Results: Ninety individuals were included, 45 with dementia and 45 without dementia (26 cognitively normal and 19 cognitively impaired but non-demented). The informant interview at the BBBABSG had a sensitivity of 86.6% and specificity of 84.4% for the diagnosis of dementia, and a sensitivity of 65.3% and specificity of 93.7% for the diagnosis of normal cognition. Conclusions: The informant interview used at the BBBABSG has a high specificity and sensitivity for the diagnosis of dementia as well as a high specificity for the diagnosis of normal cognition
Reno-protective effects of reninâangiotensin system blockade in type 2 diabetic patients: a systematic review and network meta-analysis
AIMS/HYPOTHESIS: This meta-analysis aimed to compare the renal outcomes between ACE inhibitor (ACEI)/angiotensin II receptor blocker (ARB) and other antihypertensive drugs or placebo in type 2 diabetes. METHODS: Publications were identified from Medline and Embase up to July 2011. Only randomised controlled trials comparing ACEI/ARB monotherapy with other active drugs or placebo were eligible. The outcome of end-stage renal disease, doubling of serum creatinine, microvascular complications, microalbuminuria, macroalbuminuria and albuminuria regression were extracted. Risk ratios were pooled using a random-effects model if heterogeneity was present; a fixed-effects model was used in the absence of heterogeneity. RESULTS: Of 673 studies identified, 28 were eligible (n = 13-4,912). In direct meta-analysis, ACEI/ARB had significantly lower risk of serum creatinine doubling (pooled RR = 0.66 [95% CI 0.52, 0.83]), macroalbuminuria (pooled RR = 0.70 [95% CI 0.50, 1.00]) and albuminuria regression (pooled RR 1.16 [95% CI 1.00, 1.39]) than other antihypertensive drugs, mainly calcium channel blockers (CCBs). Although the risks of end-stage renal disease and microalbuminuria were lower in the ACEI/ARB group (pooled RR 0.82 [95% CI 0.64, 1.05] and 0.84 [95% CI 0.61, 1.15], respectively), the differences were not statistically significant. The ACEI/ARB benefit over placebo was significant for all outcomes except microalbuminuria. A network meta-analysis detected significant treatment effects across all outcomes for both active drugs and placebo comparisons. CONCLUSIONS/INTERPRETATION: Our review suggests a consistent reno-protective effect of ACEI/ARB over other antihypertensive drugs, mainly CCBs, and placebo in type 2 diabetes. The lack of any differences in BP decrease between ACEI/ARB and active comparators suggest this benefit is not due simply to the antihypertensive effect
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