A ``Gaussian'' Approach to Computing Supersymmetric Effective Actions

For nonsupersymmetric theories, the one-loop effective action can be computed via zeta function regularization in terms of the functional trace of the heat kernel associated with the operator which appears in the quadratic part of the action. A method is developed for computing this functional trace by exploiting its similarity to a Gaussian integral. The procedure is extended to superspace, where it is used to compute the low energy effective action obtained by integrating out massive scalar supermultiplets in the presence of a supersymmetric Yang-Mills background.Comment: 17 pages, Latex, elsar

VibCo Engineering Test Bench

The VIBCO Engineering Test Bench was designed to be an all-inclusive, easy-to-use testing station for use by VIBCO’s engineering team. It features both loaded and unloaded testing areas, precision data acquisition instruments, and numerous sensors. The test bench was designed with convenience in mind. The main goal was to create an easy-to-use station where the majority of VIBCO’s small electric and pneumatic units can be quickly set up and tested with minimal user training. The test bench is constructed almost fully out of steel. It utilizes 2”x2”x1/4” angle steel and 1/4” steel plates. The height and other dimensions were carefully selected for ease of operation. A portion of the bench is vibration isolated using four Firestone air mounts. The bench is relatively portable, with heavy-duty casters allowing it to be transported from one area of VIBCO’s shop to another. Several modular mounting plates were designed to attach many different VIBCO models to the isolated portion of the test bench. These plates can accommodate over 60 different units each. They attach to mounting rails affixed the isolated bench top section using ¾”cap screws. Using AstroNova’s DAXUS data acquisition system and associated software, various sensors were interfaced to collect the necessary data from VIBCO’s vibration units. A thermocouple measures temperature data. A current clamp measures current draw of electric units. A tri-axial accelerometer measures acceleration of the vibrating assembly, which is in turn used to calculate both vibration speed (VPM) and force outputted by the unit

Co-expression of C9orf72 related dipeptide-repeats over 1000 repeat units reveals age- and combination-specific phenotypic profiles in Drosophila

A large intronic hexanucleotide repeat expansion (GGGGCC) within the C9orf72 (C9orf72-SMCR8 Complex Subunit) locus is the most prevalent genetic cause of both Frontotemporal Dementia (FTD) and Motor Neuron Disease (MND). In patients this expansion is typically hundreds to thousands of repeat units in length. Repeat associated non-AUG translation of the expansion leads to the formation of toxic, pathological Dipeptide-Repeat Proteins (DPRs). To date there remains a lack of in vivo models expressing C9orf72 related DPRs with a repeat length of more than a few hundred repeats. As such our understanding of how physiologically relevant repeat length DPRs efect the nervous system in an ageing in vivo system remains limited. In this study we generated Drosophila models expressing DPRs over 1000 repeat units in length, a known pathological length in humans. Using these models, we demonstrate each DPR exhibits a unique, age-dependent, phenotypic and pathological profle. Furthermore, we show co-expression of specifc DPR combinations leads to distinct, age-dependent, phenotypes not observed through expression of single DPRs. We propose these models represent a unique, in vivo, tool for dissecting the molecular mechanisms implicated in disease pathology, opening up new avenues in the study of both MND and FTD

Next generation sequencing of CLU, PICALM and CR1: pitfalls and potential solutions

CLU, PICALM and CR1 were identified as genetic risk factors for late onset Alzheimer’s disease (AD) in two large genome wide association studies (GWAS) published in 2009, but the variants that convey this alteration in disease risk, and how the genes relate to AD pathology is yet to be discovered. A next generation sequencing (NGS) project was conducted targeting CLU, CR1 and PICALM, in 96 AD samples (8 pools of 12), in an attempt to discover rare variants within these AD associated genes. Inclusion of repetitive regions in the design of the SureSelect capture lead to significant issues in alignment of the data, leading to poor specificity and a lower than expected depth of coverage. A strong positive correlation (0.964, p<0.001) was seen between NGS and 1000 genome project frequency estimates. Of the ~170 “novel” variants detected in the genes, seven SNPs, all of which were present in multiple sample pools, were selected for validation by Sanger sequencing. Two SNPs were successfully validated by this method, and shown to be genuine variants, while five failed validation. These spurious SNP calls occurred as a result of the presence of small indels and mononucleotide repeats, indicating such features should be regarded with caution, and validation via an independent method is important for NGS variant calls