Complex Line Bundles over Simplicial Complexes and their Applications

Discrete vector bundles are important in Physics and recently found remarkable applications in Computer Graphics. This article approaches discrete bundles from the viewpoint of Discrete Differential Geometry, including a complete classification of discrete vector bundles over finite simplicial complexes. In particular, we obtain a discrete analogue of a theorem of Andr\'e Weil on the classification of hermitian line bundles. Moreover, we associate to each discrete hermitian line bundle with curvature a unique piecewise-smooth hermitian line bundle of piecewise constant curvature. This is then used to define a discrete Dirichlet energy which generalizes the well-known cotangent Laplace operator to discrete hermitian line bundles over Euclidean simplicial manifolds of arbitrary dimension

Interbreeding between local and translocated populations of a cleaner fish in an experimental mesocosm predicts risk of disrupted local adaptation

Source at https://doi.org/10.1002/ece3.5246.Translocation of organisms within or outside its native range carries the risk of modifying the community of the recipient ecosystems and induces gene flow between locally adapted populations or closely related species. In this study, we evaluated the genetic consequences of large‐scale translocation of cleaner wrasses that has become a common practice within the salmon aquaculture industry in northern Europe to combat sea lice infestation. A major concern with this practice is the potential for hybridization of escaped organisms with the local, recipient wrasse population, and thus potentially introduce exogenous alleles and breaking down coadapted gene complexes in local populations. We investigated the potential threat for such genetic introgressions in a large seminatural mesocosm basin. The experimental setting represented a simulated translocation of corkwing wrasse (Symphodus melops) that occurs on a large scale in the Norwegian salmon industry. Parentage assignment analysis of mesocosm's offspring revealed 30% (195 out of 651 offspring) interbreeding between the two populations, despite their being genetically (FST = 0.094, p < 0.05) and phenotypically differentiated. Moreover, our results suggest that reproductive fitness of the translocated western population doubled that of the local southern population. Our results confirm that human translocations may overcome the impediments imposed by natural habitat discontinuities and urge for immediate action to manage the genetic resources of these small benthic wrasses

Dynamical mean-field study of ferromagnetism in the periodic Anderson model

The ferromagnetic phase diagram of the periodic Anderson model is calculated using dynamical mean-field theory in combination with the modified perturbation theory. Concentrating on the intermediate valence regime, the phase boundaries are established as function of the total electron density, the position of the atomic level and the hybridization strength. The main contribution to the magnetic moment stems from the f-electrons. The conduction band polarization is, depending on the system parameters either parallel or antiparallel to the f-magnetization. By investigating the densities of states, one observes that the change of sign of the conduction band polarization is closely connected to the hybridization gap, which is only apparent in the case of almost complete polarization of the f-electrons. Finite-temperature calculations are also performed, the Curie temperature as function of electron density and f-level position are determined. In the intermediate-valence regime, the phase transitions are found to be of second order.Comment: 12 pages, 11 figures, accepted by Phys. Rev.

Tolerable Movement Criteria for Highway Bridges

DOT-FH-11-9440This investigation included (a) a state-of-the-art assessment of tolerable bridge movements based on a literature review, an appraisal of existing design specifications and practice, the collection and analysis of field data on foundation movements, structural damage and the tolerance to movements for a large number of bridges (314) in the Unites States and Canada, and an appraisal of the reliability of the methods currently used for settlement prediction; (b) a series of analytical studies to evaluate the effect of different magnitudes and rates of differential movement on the potential level of distress produced in a wide variety of steel and concrete bridge structures of different span lengths and stiffnesses; and (c) the development of methodology for the design of bridges and their foundations that embodies a rational set of criteria for tolerable bridge movements

Lipoprotein (a) concentration is associated with plasma arachidonic acid in subjects with familial hypercholesterolemia

Elevated lipoprotein (a) (Lp[a]) is associated with cardiovascular disease (CVD) and is mainly genetically determined. Studies suggest a role of dietary fatty acids (FAs) in the regulation of Lp(a), however, no studies have investigated the association between plasma Lp(a) concentration and omega-6 FAs. We aimed to investigate whether plasma Lp(a) concentration was associated with dietary omega-6 FA intake, and plasma levels of arachidonic acid in subjects with familial hypercholesterolemia (FH). We included FH subjects with (n=68) and without (n=77) elevated Lp(a) defined as ≥75 nmol/L, and healthy subjects (n=14). Total fatty acid profile was analyzed by Gas Chromatography-Flame Ionization Detector analysis, and the daily intake of macronutrients (including the sum of omega-6 FAs: 18:2n-6, 20:2n-6, 20:3n-6 and 20:4n-6) were computed from completed food frequency questionnaires. FH subjects with elevated Lp(a) had higher plasma levels of arachidonic acid (AA) compared to FH subjects without elevated Lp(a) (P=0.03). Furthermore, both FH subjects with and without elevated Lp(a) had higher plasma levels of AA compared to controls (P<0.001). The multivariable analyses showed associations between dietary omega-6 FA intake and plasma levels of AA (P=0.02), and between plasma levels of Lp(a) and AA (P=0.006). Our data suggest a novel link between plasma Lp(a) concentration, dietary omega-6 FAs and plasma AA concentration, which may contribute to explain the small diet-induced increase in Lp(a) levels associated with lifestyle changes. Although the increase may not be clinically relevant, this association may be mechanistically interesting in understanding more of the role and regulation of Lp(a)

Comparison of Two Methods for In Vivo Estimation of the Glenohumeral Joint Rotation Center (GH-JRC) of the Patients with Shoulder Hemiarthroplasty

Determination of an accurate glenohumeral-joint rotation center (GH-JRC) from marker data is essential for kinematic and dynamic analysis of shoulder motions. Previous studies have focused on the evaluation of the different functional methods for the estimation of the GH-JRC for healthy subjects. The goal of this paper is to compare two widely used functional methods, namely the instantaneous helical axis (IHA) and symmetrical center of rotation (SCoRE) methods, for estimating the GH-JRC in vivo for patients with implanted shoulder hemiarthroplasty. The motion data of five patients were recorded while performing three different dynamic motions (circumduction, abduction, and forward flexion). The GH-JRC was determined using the CT-images of the subjects (geometric GH-JRC) and was also estimated using the two IHA and SCoRE methods. The rotation centers determined using the IHA and SCoRE methods were on average 1.47±0.62 cm and 2.07±0.55 cm away from geometric GH-JRC, respectively. The two methods differed significantly (two-tailed p-value from paired t-Test ∼0.02, post-hoc power ∼0.30). The SCoRE method showed a significant lower (two-tailed p-value from paired t-Test ∼0.03, post-hoc power ∼0.68) repeatability error calculated between the different trials of each motion and each subject and averaged across all measured subjects (0.62±0.10 cm for IHA vs. 0.43±0.12 cm for SCoRE). It is concluded that the SCoRE appeared to be a more repeatable method whereas the IHA method resulted in a more accurate estimation of the GH-JRC for patients with endoprostheses

Uptake of oxLDL and IL-10 production by macrophages requires PAFR and CD36 recruitment into the same lipid rafts

Macrophage interaction with oxidized low-density lipoprotein (oxLDL) leads to its differentiation into foam cells and cytokine production, contributing to atherosclerosis development. In a previous study, we showed that CD36 and the receptor for platelet-activating factor (PAFR) are required for oxLDL to activate gene transcription for cytokines and CD36. Here, we investigated the localization and physical interaction of CD36 and PAFR in macrophages stimulated with oxLDL. We found that blocking CD36 or PAFR decreases oxLDL uptake and IL-10 production. OxLDL induces IL-10 mRNA expression only in HEK293T expressing both receptors (PAFR and CD36). OxLDL does not induce IL-12 production. The lipid rafts disruption by treatment with βCD reduces the oxLDL uptake and IL-10 production. OxLDL induces co-immunoprecipitation of PAFR and CD36 with the constitutive raft protein flotillin-1, and colocalization with the lipid raft-marker GM1-ganglioside. Finally, we found colocalization of PAFR and CD36 in macrophages from human atherosclerotic plaques. Our results show that oxLDL induces the recruitment of PAFR and CD36 into the same lipid rafts, which is important for oxLDL uptake and IL-10 production. This study provided new insights into how oxLDL interact with macrophages and contributing to atherosclerosis development

Legumain in acute coronary syndromes: A substudy of the PLATO (Platelet Inhibition and Patient Outcomes) trial

Background The cysteine protease legumain is increased in patients with atherosclerosis, but its causal role in atherogenesis and cardiovascular disease is still unclear. The aim of the study was to investigate the association of legumain with clinical outcome in a large cohort of patients with acute coronary syndrome. Methods and Results Serum levels of legumain were analyzed in 4883 patients with acute coronary syndrome from a substudy of the PLATO (Platelet Inhibition and Patient Outcomes) trial. Levels were analyzed at admission and after 1 month follow‐up. Associations between legumain and a composite of cardiovascular death, spontaneous myocardial infarction or stroke, and its individual components were assessed by multivariable Cox regression analyses. At baseline, a 50% increase in legumain level was associated with a hazard ratio (HR) of 1.13 (95% CI, 1.04–1.21), P=0.0018, for the primary composite end point, adjusted for randomized treatment. The association remained significant after adjustment for important clinical and demographic variables (HR, 1.10; 95% CI, 1.02–1.19; P=0.013) but not in the fully adjusted model. Legumain levels at 1 month were not associated with the composite end point but were negatively associated with stroke (HR, 0.62; 95% CI, 0.44–0.88; P=0.0069), including in the fully adjusted model (HR, 0.57; 95% CI, 0.37–0.88; P=0.0114). Conclusions Baseline legumain was associated with the primary outcome in patients with acute coronary syndrome, but not in the fully adjusted model. The association between high levels of legumain at 1 month and decreased occurrence of stroke could be of interest from a mechanistic point of view, illustrating the potential dual role of legumain during atherogenesis and acute coronary syndrome. Registration URL: https://www.clini​caltr​ials.gov; Unique identifier: NCT00391872