Effects of Instructor Accent on Undergraduate Evaluations and Learning at a Catholic College

Catholic institutions of higher education are called to form citizens who fight against injustice, including persistent racial oppression. To do this, Catholic, public, and other private institutions must provide students opportunities to learn about and confront racism (Johnston, 2014). It is important that these institutions confront these issues because they employ faculty and staff who may experience systemic racism and can provide cultural knowledge to aid deconstructing racist ideologies. Undergraduate student evaluations of instructors or faculty, however, indicate discrimination against those perceived as non-white and with non-native English accents. This study focuses on one form of racism at a Catholic liberal arts college: bias against instructors who speak with a non-native English accent. This between-groups experimental study was guided by critical sociolinguistic theory and sociocultural theory to examine patterns in undergraduate engagement with material that varied only by instructor accent. Participants (n=98) completed a pre-assessment, a microlecture (randomized by accent), a post-assessment, and a microlecture evaluation. The study’s theoretical frameworks suggest that students would demonstrate bias against non-white presenters, despite the Catholic context and having no visual cues about the race or ethnicity of the presenter. Pre-and post-assessment results indicated that the microlecture had some limited effects on student learning regardless of instructor accent; however, instructors that were perceived as white had significantly higher ratings in terms of the student belief that they “showed enthusiasm about the subject matter” and that “watching this microlecture improved [their] score on the quiz.” These findings suggest continued work is needed to understand and confront issues of systemic racism in higher education

Implementing a Loosely-Coupled Integrated Assessment Model in the Pegasus Workflow Management System

Integrated assessment models (IAMs) are commonly used to explore the interactions between different modeled components of socio-environmental systems (SES). Most IAMs are built in a tightly-coupled framework so that the complex interactions between the models can be efficiently implemented within the framework in a straightforward manner. However, tightly-coupled frameworks make it more difficult to change individual models within the IAM because of the high level of integration between the models. Prioritizing flexibility over computational efficiency, the IAM presented here is built using a loosely-coupled framework and implemented in the Pegasus Workflow Management System. The modular nature of loosely-coupled systems allows each component model within the IAM to be easily exchanged for another component model from the same domain assuming each provides the same input / output interface. This flexibility allows researchers to experiment with different models for each SES component and facilitates smoother upgrades between each version of the independently developed component models

Finite temperature Casimir effect for massive scalar field in spacetime with extra dimensions

We compute the finite temperature Casimir energy for massive scalar field with general curvature coupling subject to Dirichlet or Neumann boundary conditions on the walls of a closed cylinder with arbitrary cross section, located in a background spacetime of the form $M^{d_1+1}\times \mathcal{N}^n$, where $M^{d_1+1}$ is the $(d_1+1)$-dimensional Minkowski spacetime and $\mathcal{N}^n$ is an $n$-dimensional internal manifold. The Casimir energy is regularized using the criteria that it should vanish in the infinite mass limit. The Casimir force acting on a piston moving freely inside the closed cylinder is derived and it is shown that it is independent of the regularization procedure. By letting one of the chambers of the cylinder divided by the piston to be infinitely long, we obtain the Casimir force acting on two parallel plates embedded in the cylinder. It is shown that if both the plates assume Dirichlet or Neumann boundary conditions, the strength of the Casimir force is reduced by the increase in mass. Under certain conditions, the passage from massless to massive will change the nature of the force from long range to short range. Other properties of the Casimir force such as its sign, its behavior at low and high temperature, and its behavior at small and large plate separations, are found to be similar to the massless case. Explicit exact formulas and asymptotic behaviors of the Casimir force at different limits are derived. The Casimir force when one plate assumes Dirichlet boundary condition and one plate assumes Neumann boundary condition is also derived and shown to be repulsive.Comment: 28 pages, 4 figure

Membranous Glomerulonephritis With Crescents.

INTRODUCTION: Membranous glomerulonephritis (MGN) is rarely associated with necrotizing and crescentic glomerulonephritis (NCGN). METHODS: We report the clinical and pathologic findings in 15 patients with MGN and NCGN associated with anti-neutrophil cytoplasm antibodies (ANCAs), anti-glomerular basement membrane (GBM), or anti-phospholipase A2 receptor (PLA2R) antibodies. RESULTS: The cohort consisted of 15 patients: 7 males and 8 females with a median age of 63 years (range: 18-79). In 12 of 15 patients, MGN and NCGN were diagnosed at the time of the biopsy, and in 3 cases, MGN predated the NCGN. ANCA was positive in 7 cases (6 MPO myeloperoxidase (MPO)-ANCA and 1 PR3-ANCA), anti-GBM antibodies were detected in 5 cases, and anti-PLA2R antibodies were found in 2 cases. One case was negative for all antibodies. Microscopic hematuria was present in all but one patient who was anuric, and median urinary protein-to-creatinine ratio was 819.5 mg/mmol (range: 88-5600). Pathologic evaluation revealed MGN and NCGN with crescents involving 28% of glomeruli (median; range: 5%-100%). Follow-up was available for all 15 patients; all were treated with steroids; 10 with cyclophosphamide, and 6 also received rituximab. At a median follow-up of 72 months, 9 had stabilization or improvement of renal function, 6 had progressed to end-stage renal disease, and 4 died during the follow-up period. CONCLUSION: MGN with crescents associated with ANCAs or anti-GBM antibodies is a rare dual glomerulopathy. Patients present with heavy proteinuria, microscopic hematuria, and acute kidney injury and should be treated for a rapidly progressive glomerulonephritis. Prognosis is variable, and 40% of patients progress to end-stage renal disease

Transition of the dark energy equation of state in an interacting holographic dark energy model

A model of holographic dark energy with an interaction with matter fields has been investigated. Choosing the future event horizon as an IR cutoff, we have shown that the ratio of energy densities can vary with time. With the interaction between the two different constituents of the universe, we observed the evolution of the universe, from early deceleration to late time acceleration. In addition, we have found that such an interacting dark energy model can accommodate a transition of the dark energy from a normal state where $w_D>-1$ to $w_D<-1$ phantom regimes. Implications of interacting dark energy model for the observation of dark energy transition has been discussed.Comment: revised version, references added. Accepted for publication in PL

Casimir Effect in Spacetime with Extra Dimensions -- From Kaluza-Klein to Randall-Sundrum Models

In this article, we derive the finite temperature Casimir force acting on a pair of parallel plates due to a massless scalar field propagating in the bulk of a higher dimensional brane model. In contrast to previous works which used approximations for the effective masses in deriving the Casimir force, the formulas of the Casimir force we derive are exact formulas. Our results disprove the speculations that existence of the warped extra dimension can change the sign of the Casimir force, be it at zero or any finite temperature.Comment: 9 pages, 3 figure. Final version accepted by Phys. Lett.

Leptin-Mediated Changes in the Human Metabolome.

CONTEXT: While severe obesity due to congenital leptin deficiency is rare, studies in patients before and after treatment with leptin can provide unique insights into the role that leptin plays in metabolic and endocrine function. OBJECTIVE: The aim of this study was to characterize changes in peripheral metabolism in people with congenital leptin deficiency undergoing leptin replacement therapy, and to investigate the extent to which these changes are explained by reduced caloric intake. DESIGN: Ultrahigh performance liquid chromatography-tandem mass spectroscopy (UPLC-MS/MS) was used to measure 661 metabolites in 6 severely obese people with congenital leptin deficiency before, and within 1 month after, treatment with recombinant leptin. Data were analyzed using unsupervised and hypothesis-driven computational approaches and compared with data from a study of acute caloric restriction in healthy volunteers. RESULTS: Leptin replacement was associated with class-wide increased levels of fatty acids and acylcarnitines and decreased phospholipids, consistent with enhanced lipolysis and fatty acid oxidation. Primary and secondary bile acids increased after leptin treatment. Comparable changes were observed after acute caloric restriction. Branched-chain amino acids and steroid metabolites decreased after leptin, but not after acute caloric restriction. Individuals with severe obesity due to leptin deficiency and other genetic obesity syndromes shared a metabolomic signature associated with increased BMI. CONCLUSION: Leptin replacement was associated with changes in lipolysis and substrate utilization that were consistent with negative energy balance. However, leptin's effects on branched-chain amino acids and steroid metabolites were independent of reduced caloric intake and require further exploration

The metabolic syndrome- associated small G protein ARL15 plays a role in adipocyte differentiation and adiponectin secretion.

Common genetic variants at the ARL15 locus are associated with plasma adiponectin, insulin and HDL cholesterol concentrations, obesity, and coronary atherosclerosis. The ARL15 gene encodes a small GTP-binding protein whose function is currently unknown. In this study adipocyte-autonomous roles for ARL15 were investigated using conditional knockdown of Arl15 in murine 3T3-L1 (pre)adipocytes. Arl15 knockdown in differentiated adipocytes impaired adiponectin secretion but not adipsin secretion or insulin action, while in preadipocytes it impaired adipogenesis. In differentiated adipocytes GFP-tagged ARL15 localized predominantly to the Golgi with lower levels detected at the plasma membrane and intracellular vesicles, suggesting involvement in intracellular trafficking. Sequencing of ARL15 in 375 severely insulin resistant patients identified four rare heterozygous variants, including an early nonsense mutation in a proband with femorogluteal lipodystrophy and non classical congenital adrenal hyperplasia, and an essential splice site mutation in a proband with partial lipodystrophy and a history of childhood yolk sac tumour. No nonsense or essential splice site mutations were found in 2,479 controls, while five such variants were found in the ExAC database. These findings provide evidence that ARL15 plays a role in adipocyte differentiation and adiponectin secretion, and raise the possibility that human ARL15 haploinsufficiency predisposes to lipodystrophy

Quintom cosmologies admitting either tracking or phantom attractors

In this paper we investigate the evolution of a class of cosmologies fuelled by quintom dark energy and dark matter. Quintom dark energy is a hybrid of quintessence and phantom which involves the participation of two reals scalar fields playing the roles of those two types of dark energy. In that framework we examine from a dynamical systems perspective the possibility that those fields are coupled among them by considering an exponential potential with an interesting functional dependence similar but not identical to others studied before. The model we consider represents a counterexample to the typical behavior of quintom models with exponential potentials because it admits either tracking attractors ($w=0$), or phantom attractors ($w<-1$).Comment: revtex4, 7 pages, 6 figure