The Fermi Liquid as a Renormalization Group Fixed Point: the Role of Interference in the Landau Channel

We apply the finite-temperature renormalization-group (RG) to a model based on an effective action with a short-range repulsive interaction and a rotation invariant Fermi surface. The basic quantities of Fermi liquid theory, the Landau function and the scattering vertex, are calculated as fixed points of the RG flow in terms of the effective action's interaction function. The classic derivations of Fermi liquid theory, which apply the Bethe-Salpeter equation and amount to summing direct particle-hole ladder diagrams, neglect the zero-angle singularity in the exchange particle-hole loop. As a consequence, the antisymmetry of the forward scattering vertex is not guaranteed and the amplitude sum rule must be imposed by hand on the components of the Landau function. We show that the strong interference of the direct and exchange processes of particle-hole scattering near zero angle invalidates the ladder approximation in this region, resulting in temperature-dependent narrow-angle anomalies in the Landau function and scattering vertex. In this RG approach the Pauli principle is automatically satisfied. The consequences of the RG corrections on Fermi liquid theory are discussed. In particular, we show that the amplitude sum rule is not valid.Comment: 25 pages, RevTeX 3.

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

Whole genome sequence association analysis of fasting glucose and fasting insulin levels in diverse cohorts from the NHLBI TOPMed program

The genetic determinants of fasting glucose (FG) and fasting insulin (FI) have been studied mostly through genome arrays, resulting in over 100 associated variants. We extended this work with high-coverage whole genome sequencing analyses from fifteen cohorts in NHLBI’s Trans-Omics for Precision Medicine (TOPMed) program. Over 23,000 non-diabetic individuals from five race-ethnicities/populations (African, Asian, European, Hispanic and Samoan) were included. Eight variants were significantly associated with FG or FI across previously identified regions MTNR1B, G6PC2, GCK, GCKR and FOXA2. We additionally characterize suggestive associations with FG or FI near previously identified SLC30A8, TCF7L2, and ADCY5 regions as well as APOB, PTPRT, and ROBO1. Functional annotation resources including the Diabetes Epigenome Atlas were compiled for each signal (chromatin states, annotation principal components, and others) to elucidate variant-to-function hypotheses. We provide a catalog of nucleotide-resolution genomic variation spanning intergenic and intronic regions creating a foundation for future sequencing-based investigations of glycemic traits

The CAMU Rule: A tool for implementing a protective, cost-effective remedy at the Fernald Environmental Management Project

The Fernald Environmental Management Project (FEMP) is a former uranium processing facility currently under remediation pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act as amended (CERCLA). Contamination at the FEMP consists of low-level radioactivity, hazardous substances, hazardous wastes and/or mixed wastes. Regulations promulgated under the Resource Conservation and Recovery Act as amended (RCRA) are evaluated as applicable or relevant and appropriate requirements (ARARs) for remediation of the FEMP. Historically, joint CERCLA-RCRA guidance dictated that hazardous waste could not be treated, or moved out of the designated area of contiguous contamination (AOC), without triggering land disposal restrictions (LDRs) or minimum technology requirements (MTRs). To avoid invoking these stringent requirements, in situ capping was chosen as the lower cost remedy at many sites, although on-site disposal and/or treatment of hazardous wastes would have been more protective. The Corrective Action Management Units (CAMUs) and Temporary Units (TUs) Final Rule [58 FR 8658, Vol. 58, No. 29, hereinafter the {open_quotes}CAMU Rule{close_quotes}], promulgated on February 16, 1993, provides facilities regulated under RCRA corrective action authority with greater flexibility to move, treat, and dispose of wastes on site without triggering LDRs or MTRs, thereby encouraging application of innovative technologies and more protective remedies. The waste acceptance criteria for the on-site disposal facility is based on site-specific considerations including the mobility of the contaminants through the underlying site geology and the protectiveness of the engineered liners. Application of the {open_quotes}CAMU Rule{close_quotes} allows for disposition in the on-site facility based on these technical considerations rather than on regulatory classifications

Genetic drivers of heterogeneity in type 2 diabetes pathophysiology

Type 2 diabetes (T2D) is a heterogeneous disease that develops through diverse pathophysiological processes1,2 and molecular mechanisms that are often specific to cell type3,4. Here, to characterize the genetic contribution to these processes across ancestry groups, we aggregate genome-wide association study data from 2,535,601 individuals (39.7% not of European ancestry), including 428,452 cases of T2D. We identify 1,289 independent association signals at genome-wide significance (P &lt; 5 × 10-8) that map to 611 loci, of which 145 loci are, to our knowledge, previously unreported. We define eight non-overlapping clusters of T2D signals that are characterized by distinct profiles of cardiometabolic trait associations. These clusters are differentially enriched for cell-type-specific regions of open chromatin, including pancreatic islets, adipocytes, endothelial cells and enteroendocrine cells. We build cluster-specific partitioned polygenic scores5 in a further 279,552 individuals of diverse ancestry, including 30,288 cases of T2D, and test their association with T2D-related vascular outcomes. Cluster-specific partitioned polygenic scores are associated with coronary artery disease, peripheral artery disease and end-stage diabetic nephropathy across ancestry groups, highlighting the importance of obesity-related processes in the development of vascular outcomes. Our findings show the value of integrating multi-ancestry genome-wide association study data with single-cell epigenomics to disentangle the aetiological heterogeneity that drives the development and progression of T2D. This might offer a route to optimize global access to genetically informed diabetes care.</p

Fisioterapia após substituição artroscópica do ligamento cruzado cranial em cães: I - avaliação clínica, radiográfica e ultrassonográfica Physiotherapy after arthroscopic repair of the cranial cruciate ligament in dogs: I - clinical, radiographic, and ultrasonographic evaluation

Foram avaliadas a aplicabilidade da cirurgia artroscópica na substituição do ligamento cruzado cranial (LCC) e o efeito da fisioterapia pós-operatória, por meio de exames clínicos, radiográficos e ultrassonográficos, em 16 cães sem raça definida, machos, com pesos entre 19,2 e 26,3kg, submetidos à ruptura experimental do LCC e subsequente substituição deste ligamento pelo enxerto autógeno da fascia lata. Os animais foram distribuídos em dois grupos de oito cada: no grupo I os cães foram submetidos ao programa de fisioterapia pós-operatória e no grupo II à imobilização temporária do membro. Por meio dos exames citados, não foram verificadas diferenças significativas entre os dois grupos, e ambos demonstraram sinais de processo articular degenerativo. A função do membro foi avaliada com auxílio da plataforma de força, e os animais do grupo I apresentaram melhor apoio do membro operado durante o período de reabilitação. Conclui-se que a cirurgia artroscópica é uma técnica eficaz para substituição do LCC em cães, apesar de não impedir o desenvolvimento da doença articular degenerativa, e que a fisioterapia permite recuperação mais rápida no apoio do membro durante o período de reabilitação.<br>The reconstruction of experimentally ruptured cranial cruciate ligament (CCL) under arthroscopic guidance and the effects of an early postoperative rehabilitation program by clinical, radiographic, and ultrasonographic exams were evaluated. Sixteen male mongrel dogs weighing from 19.2 to 26.3kg had the CCL experimentally ruptured and the stifle joint was stabilized by the use of an intracapsular arthroscopical technique with fascia lata as an autogenous graft. Eight dogs were included in a postoperative physiotherapy group and the other eight in a temporary immobilization group. From serial clinical, radiographic, and ultrasonographic examinations, no differences between groups were observed, although all dogs had showed signs of degenerative joint disease. Limb function was determined after surgery using force platform analysis, and the animals from physiotherapy group had significantly better results during rehabilitation period. It can be concluded that arthroscopic surgery for reconstruction of the cranial cruciate ligament is an efficient method to be used in dogs, in spite of not preventing the degenerative joint disease, and the physiotherapy has beneficial effects on early limb function during the rehabilitation period