487 research outputs found
Inferring Population Preferences via Mixtures of Spatial Voting Models
Understanding political phenomena requires measuring the political
preferences of society. We introduce a model based on mixtures of spatial
voting models that infers the underlying distribution of political preferences
of voters with only voting records of the population and political positions of
candidates in an election. Beyond offering a cost-effective alternative to
surveys, this method projects the political preferences of voters and
candidates into a shared latent preference space. This projection allows us to
directly compare the preferences of the two groups, which is desirable for
political science but difficult with traditional survey methods. After
validating the aggregated-level inferences of this model against results of
related work and on simple prediction tasks, we apply the model to better
understand the phenomenon of political polarization in the Texas, New York, and
Ohio electorates. Taken at face value, inferences drawn from our model indicate
that the electorates in these states may be less bimodal than the distribution
of candidates, but that the electorates are comparatively more extreme in their
variance. We conclude with a discussion of limitations of our method and
potential future directions for research.Comment: To be published in the 8th International Conference on Social
Informatics (SocInfo) 201
Areola and Nipple-Areola-Sparing Mastectomy for Breast Cancer Treatment and Risk Reduction: Report of an Initial Experience in a Community Hospital Setting
Modulation of Retinal Wound Healing by Systemically Administered Bone Marrow-Derived Mesenchymal Stem Cells
Dupuytren's contracture: a retrospective database analysis to determine hospitalizations in the Netherlands
Background: Dupuytren's contracture is a condition of the palmar fascia involving contractures of the fascia and skin in the hand. Current treatment for Dupuytren's contracture is mainly limited to surgery. In the Netherlands, little is known about the prevalence of Dupuytren's contracture. In this study we determined the prevalence of patients with a hospitalization for Dupuytren's contracture in the Netherlands and characterized their (re)hospitalizations. Methods. From the PHARMO database, which consists of multiple observational databases linked on a patient level, all patients hospitalized for Dupuytren's contracture between 2004 and 2007 were included in the source population (ICD-9-CM code 728.6). Numbers from this source population were used to provide estimates of hospitalizations for Dupuytren's contracture in the Netherlands. Patients with a medical history in the PHARMO database of at least 12 months before their hospitalization were included in the study cohort and followed until end of data collection, death, or end of study period, whichever occurred first. Type of admission, length of stay, recorded procedures, treating specialty, number of rehospitalizations for Dupuytren's contracture, and time to first rehospitalization were assessed. Results: Of 3, 126 patients included in the source population, 3, 040 were included in the study population. The overall prevalence of patients with a hospitalization for Dupuytren'
Vitamins A, C and E and the risk of breast cancer: results from a case-control study in Greece
Although several dietary compounds are hypothesized to have anticarcinogenic properties, the role ofpecific micronutrients in the development of breast cancer remains unclear. To address this issue, we assessed intake of retinol,
β-carotene, vitamin C and vitamin E in relation to breast cancer risk in a case–control study in Greece. Eight hundrednd twenty women with histologically confirmed breast cancer were compared with 1548 control women. Dietary data were collectedhrough a 115-item semiquantitative food frequency questionnaire. Data were modelled by logistic regression, with adjustment forotal energy intake and established breast cancer risk factors, as well as mutual adjustment among the micronutrients. Amongost-menopausal women, there was no association between any of the micronutrients evaluated and risk of breast cancer. Amongremenopausal women, β-carotene, vitamin C and vitamin E were each inversely associated with breast cancer risk, but afterutual adjustment among the three nutrients only β-carotene remained significant; the odds ratio (OR) for a one-quintilencrease in β-carotene intake was 0.84 (95% confidence interval 0.73–0.97). The inverse association observed with
β-carotene intake, however, is slightly weaker than the association previously observed with vegetable intake in these data,aising the possibility that the observed β-carotene effect is accounted for by another component of vegetables. ©1999 Cancer Research Campaig
Structural and Mutational Analysis of Functional Differentiation between Synaptotagmins-1 and -7
Synaptotagmins are known to mediate diverse forms of Ca2+-triggered exocytosis through their C2 domains, but the principles underlying functional differentiation among them are unclear. Synaptotagmin-1 functions as a Ca2+ sensor in neurotransmitter release at central nervous system synapses, but synaptotagmin-7 does not, and yet both isoforms act as Ca2+ sensors in chromaffin cells. To shed light into this apparent paradox, we have performed rescue experiments in neurons from synaptotagmin-1 knockout mice using a chimera that contains the synaptotagmin-1 sequence with its C2B domain replaced by the synaptotagmin-7 C2B domain (Syt1/7). Rescue was not achieved either with the WT Syt1/7 chimera or with nine mutants where residues that are distinct in synaptotagmin-7 were restored to those present in synaptotagmin-1. To investigate whether these results arise because of unique conformational features of the synaptotagmin-7 C2B domain, we determined its crystal structure at 1.44 Å resolution. The synaptotagmin-7 C2B domain structure is very similar to that of the synaptotagmin-1 C2B domain and contains three Ca2+-binding sites. Two of the Ca2+-binding sites of the synaptotagmin-7 C2B domain are also present in the synaptotagmin-1 C2B domain and have analogous ligands to those determined for the latter by NMR spectroscopy, suggesting that a discrepancy observed in a crystal structure of the synaptotagmin-1 C2B domain arose from crystal contacts. Overall, our results suggest that functional differentiation in synaptotagmins arises in part from subtle sequence changes that yield dramatic functional differences
Genetic Evidence Highlights Potential Impacts of By-Catch to Cetaceans
Incidental entanglement in fishing gear is arguably the most serious threat to many populations of small cetaceans, judging by the alarming number of captured animals. However, other aspects of this threat, such as the potential capture of mother-offspring pairs or reproductive pairs, could be equally or even more significant but have rarely been evaluated. Using a combination of demographic and genetic data we provide evidence that i) Franciscana dolphin pairs that are potentially reproductive and mother-offspring pairs form temporal bonds, and ii) are entangled simultaneously. Our results highlight potential demographic and genetic impacts of by-catch to cetacean populations: the joint entanglement of mother-offspring or reproductive pairs, compared to random individuals, might exacerbate the demographic consequences of by-catch, and the loss of groups of relatives means that significant components of genetic diversity could be lost together. Given the social nature of many odontocetes (toothed cetaceans), we suggest that these potential impacts could be rather general to the group and therefore by-catch could be more detrimental than previously considered
Lipoprotein associated phospholipase A2: role in atherosclerosis and utility as a biomarker for cardiovascular risk
Atherosclerosis and its clinical manifestations are widely prevalent throughout the world. Atherogenesis is highly complex and modulated by numerous genetic and environmental risk factors. A large body of basic scientific and clinical research supports the conclusion that inflammation plays a significant role in atherogenesis along the entire continuum of its progression. Inflammation adversely impacts intravascular lipid handling and metabolism, resulting in the development of macrophage foam cell, fatty streak, and atheromatous plaque formation. Given the enormous human and economic cost of myocardial infarction, ischemic stroke, peripheral arterial disease and amputation, and premature death and disability, considerable effort is being committed to refining our ability to correctly identify patients at heightened risk for atherosclerotic vascular disease and acute cardiovascular events so that they can be treated earlier and more aggressively. Serum markers of inflammation have emerged as an important component of risk factor burden. Lipoprotein-associated phospholipase A2 (Lp-PLA2) potentiates intravascular inflammation and atherosclerosis. A variety of epidemiologic studies support the utility of Lp-PLA2 measurements for estimating and further refining cardiovascular disease risk. Drug therapies to inhibit Lp-PLA2 are in development and show considerable promise, including darapladib, a specific molecular inhibitor of the enzyme. In addition to substantially inhibiting Lp-PLA2 activity, darapladib reduces progression of the necrotic core volume of human coronary artery atheromatous plaque. The growing body of evidence points to an important role and utility for Lp-PLA2 testing in preventive and personalized clinical medicine
Circulating and PBMC Lp-PLA2 Associate Differently with Oxidative Stress and Subclinical Inflammation in Nonobese Women (Menopausal Status)
BACKGROUND: This study aimed to determine the association of lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) activity in circulation and peripheral blood mononuclear cells (PBMCs) with inflammatory and oxidative stress markers in nonobese women and according to menopausal status. Lp-PLA(2) activity, a marker for cardiovascular risk is associated with inflammation and oxidative stress. METHODOLOGY/PRINCIPAL FINDINGS: Eighty postmenopausal women (53.0±4.05 yr) and 96 premenopausal women (39.7±9.25 yr) participated in this study. Lp-PLA(2) activities, interleukin (IL)-6, tumor necrosis factor (TNF)-α, and IL-1β in plasma as well as in PBMCs were measured. Plasma ox-LDL was also measured. Postmenopausal women demonstrated higher circulating levels of ox-LDL and IL-6, as well as IL-6, TNF-α, and IL-1β in PBMCs, than premenopausal women. In both groups, plasma Lp-PLA(2) activity positively correlated with Lp-PLA(2) activity in PBMCs and plasma ox-LDL. In premenopausal women, Lp-PLA(2) activities in plasma and PBMCs positively correlated with IL-6, TNF-α, and IL-1β in PBMCs. In postmenopausal women, plasma ox-LDL positively correlated with PBMC cytokine production. In subgroup analysis of postmenopausal women according to plasma ox-LDL level (median level: 48.715 U/L), a significant increase in Lp-PLA(2) activity in the plasma but not the PBMCs was found in the high ox-LDL subgroup. Plasma Lp-PLA(2) activity positively correlated with unstimulated PBMC Lp-PLA(2) activity in the low ox-LDL subgroup (r = 0.627, P<0.001), whereas in the high ox-LDL circulating Lp-PLA(2) activity positively correlated with plasma ox-LDL (r = 0.390, P = 0.014) but not with Lp-PLA(2) activity in PBMCs. CONCLUSIONS/SIGNIFICANCE: The lack of relation between circulating Lp-PLA(2) activity and Lp-PLA(2) activity in PBMCs was found in postmenopausal women with high ox-LDL. This may indicate other sources of circulating Lp-PLA(2) activity except PBMC in postmenopausal women with high ox-LDL. We also demonstrated that circulating Lp-PLA(2) and PBMC secreted Lp-PLA(2) associate differently with markers of oxidative stress and sub clinical inflammation in nonobese women, particularly according to the menopausal states
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