Finite Bubble Statistics Constrain Late Cosmological Phase Transitions.

We consider first order cosmological phase transitions (PTs) happening at late times below standard model temperatures T_{PT}≲GeV. The inherently stochastic nature of bubble nucleation and the finite number of bubbles associated with a late-time PT lead to superhorizon fluctuations in the PT completion time. We compute how such fluctuations eventually source curvature fluctuations with universal properties, independent of the microphysics of the PT dynamics.

Summer undergraduate biomedical research program for underrepresented minority students in a rural, low-income state.

Introduction: Diversity can enhance the agenda and quality of biomedical research, but a dearth of underrepresented minorities and women serve as biomedical researchers. The study purpose was to examine the impact of the a summer undergraduate research program on self-efficacy in research, scientific communication, and leadership as well as scientific identity, valuing objectives of the scientific community, and intent to pursue a biomedical research career.

Methods: Underrepresented minority and female undergraduate students participated in a mentored research experience in a rural, low-income state.

Maximizing Direct Detection with Highly Interactive Particle Relic Dark Matter.

We estimate the maximum direct detection cross section for sub-GeV dark matter (DM) scattering off nucleons. For DM masses in the range 10 keV-100 MeV, cross sections greater than 10^{-36}-10^{-30}  cm^{2} seem implausible. We present a DM candidate which realizes this maximum cross section: highly interactive particle relics (HYPERs).

Outcomes of the UAMS summer undergraduate research program to increase diversity in research and health professions.

The University of Arkansas for Medical Sciences (UAMS) Summer Undergraduate Research Program (SURP) aims to increase diversity in research and health-related careers. The SURP provides underrepresented minority (URM) and disadvantaged students with research, mentoring, and networking experiences; real-life surgical observations; and simulated cardiovascular demonstrations. A postprogram survey was developed to assess program outcomes and explore ways of improving the program to stimulate URM and disadvantaged students' interest in research and health-related careers.

Resonant Self-Interacting Dark Matter from Dark QCD.

We present new models utilizing QCD-like dark sectors to resolve small-scale structure problems. These models of resonant self-interacting dark matter in a dark sector with QCD are based on analogies to the meson spectra in standard model QCD. We introduce a simple model that realizes resonant self-interaction (analogous to the ϕ-K-K system) and thermal freeze-out, in which dark mesons are made of two light quarks.

Performance measures of racially underrepresented Ph.D. students in biomedical sciences: The UAMS IMSD Program Outcomes.

The purpose of this study was to identify performance measures of racially underrepresented minority (RUM) Ph.D. trainees who needed additional training initiatives to assist with completing the UAMS biomedical science degree.

Directly Detecting Signals from Absorption of Fermionic Dark Matter.

We present a new class of direct detection signals; absorption of fermionic dark matter. We enumerate the operators through dimension six which lead to fermionic absorption, study their direct detection prospects, and summarize additional constraints on their suppression scale. Such dark matter is inherently unstable as there is no symmetry which prevents dark matter decays.

The effects of temperature and seasons on subcutaneous white adipose tissue in humans: evidence for thermogenic gene induction.

Context: Although brown adipose tissue (BAT) activity is increased by a cold environment, little is known of the response of human white adipose tissue (WAT) to the cold.

Design: We examined both abdominal and thigh subcutaneous (SC) WAT from 71 subjects who were biopsied in the summer or winter, and adipose expression was assessed after an acute cold stimulus applied to the thigh of physically active young subjects.

Results: In winter, UCP1 and PGC1α mRNA were increased 4 to 10-fold (p < 0.

Regulation of thrombospondin-1 expression in alternatively activated macrophages and adipocytes: role of cellular cross talk and omega-3 fatty acids.

Thrombospondin-1 (TSP-1) expression in human adipose positively correlates with body mass index and may contribute to adipose dysfunction by activating transforming growth factor-β and/or inhibiting angiogenesis. Our objective was to determine how TSP-1 is regulated in adipocytes and polarized macrophages using a coculture system and to determine whether fatty acids, including the ω-3 fatty acid docosahexaenoic acid (DHA), regulate TSP-1 expression. Coculture of M1, M2a or M2c macrophages with adipocytes induced TSP-1 gene expression in adipocytes (from 2.

Omega-3 fatty acids reduce adipose tissue macrophages in human subjects with insulin resistance.

Fish oils (FOs) have anti-inflammatory effects and lower serum triglycerides. This study examined adipose and muscle inflammatory markers after treatment of humans with FOs and measured the effects of ω-3 fatty acids on adipocytes and macrophages in vitro. Insulin-resistant, nondiabetic subjects were treated with Omega-3-Acid Ethyl Esters (4 g/day) or placebo for 12 weeks.

Regulation of small ubiquitin-like modifier-1, nuclear receptor coreceptor, histone deacetylase 3, and peroxisome proliferator-activated receptor-γ in human adipose tissue.

Background: This study investigated the regulation of peroxisome proliferator-activated receptor-γ (PPARγ), the histone deacetylase 3 (HDAC3)-nuclear receptor coreceptor (NCoR) complex (a corepressor of transcription used by PPARγ), and small ubiquitin-like modifier-1 (SUMO-1) (a posttranslational modifier of PPARγ) in human adipose tissue and both adipocyte and macrophage cell lines. The objective was to determine whether there were alterations in the human adipose tissue gene expression levels of PPARγ, HDAC3, NCoR, and SUMO-1 associated either with obesity or with treatment of impaired glucose tolerance (IGT) subjects with insulin-sensitizing medications.

Methods: We obtained subcutaneous adipose tissue biopsies from 86 subjects with a wide range of body mass index (BMI) and insulin sensitivity (S(I)).

Effect of endoplasmic reticulum stress on inflammation and adiponectin regulation in human adipocytes.

The endoplasmic reticulum (ER) of adipocytes plays a major role in the assembly and secretion of adipokines. The levels of serum adiponectin, secreted by adipocytes, are decreased in insulin resistance, diabetes, and obesity. The role of ER stress in downregulating adiponectin levels has been demonstrated in mouse models of obesity.

Adipose tissue extracellular matrix and vascular abnormalities in obesity and insulin resistance.

Context: Insulin resistance is associated with inflammation, fibrosis, and hypoxia in adipose tissue.

Objective: This study was intended to better characterize the extracellular matrix (ECM) and vascularity of insulin-resistant adipose tissue.

Design: Adipose expression of collagens, elastin, and angiogenic factors was assessed using real-time RT-PCR and immunohistochemistry (IHC) in abdominal sc adipose tissue.

Association of scavenger receptors in adipose tissue with insulin resistance in nondiabetic humans.

Objective: Scavenger receptors play crucial roles in the pathogenesis of atherosclerosis, but their role in insulin resistance has not been explored. We hypothesized that scavenger receptors are present in human adipose tissue resident macrophages, and their gene expression is regulated by adiponectin and thaizolidinediones.

Methods And Results: The gene expression of scavenger receptors including scavenger receptor-A (SRA), CD36, and lectin-like oxidized LDL receptor-1 (LOX-1) were studied in subcutaneous adipose tissue of nondiabetic subjects and in vitro.

Muscle inflammatory response and insulin resistance: synergistic interaction between macrophages and fatty acids leads to impaired insulin action.

Obesity is characterized by adipose tissue expansion as well as macrophage infiltration of adipose tissue. This results in an increase in circulating inflammatory cytokines and nonesterified fatty acids, factors that cause skeletal muscle insulin resistance. Whether obesity also results in skeletal muscle inflammation is not known.

Stearoyl-coenzyme A desaturase 1 gene expression increases after pioglitazone treatment and is associated with peroxisomal proliferator-activated receptor-gamma responsiveness.

Context And Objective: Stearoyl-coenzyme A desaturase (SCD1) is the rate-limiting enzyme that converts palmitoyl- and stearoyl-coenzyme A to palmitoleoyl- and oleoyl-cownzyme A, respectively. SCD-deficient mice are protected from obesity, and the ob/ob mouse has high levels of SCD. This study was designed to better characterize SCD1 gene and protein expression in humans with varying insulin sensitivity.

Expression of p107 and p130 during human adipose-derived stem cell adipogenesis.

Within the first 24h of hormonally stimulated adipocyte differentiation, murine 3T3-L1 preadipocytes undergo a mitotic expansion phase prior to terminal differentiation. During this time, the cell cycle regulatory proteins, p130 and p107 undergo dramatic differential expression and the transient increase in expression of p107 appears to be required for terminal differentiation. Recently, human adipose-derived human stem cells (hASC) of mesenchymal origin have been used as a model of human adipocyte differentiation and we sought to determine if differentiating hASC undergo clonal expansion and if the regulated expression of p130/p107 was similar to that observed during 3T3-L1 adipogenesis.

Thrombospondin-1 is an adipokine associated with obesity, adipose inflammation, and insulin resistance.

Objective: We examined the relationship between the expression of thrombospondin (TSP)1, an antiangiogenic factor and regulator of transforming growth factor-beta activity, obesity, adipose inflammation, and insulin resistance.

Research Design And Methods: TSP1 gene expression was quantified in subcutaneous adipose tissue (SAT) of 86 nondiabetic subjects covering a wide range of BMI and insulin sensitivity, from visceral adipose (VAT) and SAT from 14 surgical patients and from 38 subjects with impaired glucose tolerance randomized to receive either pioglitazone or metformin for 10 weeks. An adipocyte culture system was also used to assess the effects of pioglitazone and coculture with macrophages on TSP1 gene expression.

Retinol binding protein 4 expression in humans: relationship to insulin resistance, inflammation, and response to pioglitazone.

Context: Retinol binding protein 4 (RBP4) was recently found to be expressed and secreted by adipose tissue, and was strongly associated with insulin resistance.

Objective: The aim was to determine the relationship between RBP4 and obesity, insulin resistance, and other markers of insulin resistance in humans.

Design And Patients: RBP4 mRNA levels in adipose tissue and muscle of nondiabetic human subjects with either normal or impaired glucose tolerance (IGT) were studied, along with plasma RBP4.

Human visfatin expression: relationship to insulin sensitivity, intramyocellular lipids, and inflammation.

Context: Visfatin (VF) is a recently described adipokine preferentially secreted by visceral adipose tissue (VAT) with insulin mimetic properties.

Objective: The aim of this study was to examine the association of VF with insulin sensitivity, intramyocellular lipids (IMCL), and inflammation in humans.

Design And Patients: VF mRNA was examined in paired samples of VAT and abdominal sc adipose tissue (SAT) obtained from subjects undergoing surgery.

Lipin expression is attenuated in adipose tissue of insulin-resistant human subjects and increases with peroxisome proliferator-activated receptor gamma activation.

Lipin-alpha and -beta are the alternatively spliced gene products of the Lpin1 gene, whose product lipin is required for adipocyte differentiation. Lipin deficiency causes lipodystrophy, fatty liver, and insulin resistance in mice, whereas adipose tissue lipin overexpression results in increased adiposity but improved insulin sensitivity. To assess lipin expression and its relation to insulin resistance in humans, we examined lipin-alpha and -beta mRNA levels in subjects with normal or impaired glucose tolerance.

Pioglitazone induces apoptosis of macrophages in human adipose tissue.

Metabolic syndrome and type 2 diabetes mellitus are associated with an increased number of macrophage cells that infiltrate white adipose tissue (WAT). Previously, we demonstrated that the treatment of subjects with impaired glucose tolerance (IGT) with the peroxisome proliferator-activated receptor gamma (PPARgamma) agonist pioglitazone resulted in a decrease in macrophage number in adipose tissue. Here, adipose tissue samples from IGT subjects treated with pioglitazone were examined for apoptosis with terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) staining.

Comparative expression profiling in primary and immortalized endothelial cells: changes in gene expression in response to hydroxy methylglutaryl-coenzyme A reductase inhibition.

Immortalized cell lines offer significant logistical advantages over primary cells when used for in-vitro studies. Immortalized cells may, however, exhibit important differences relative to their primary cell counterparts. In this study, microarrays were used to make a genome-wide comparison between primary human umbilical vein endothelial cells (HUVECs) and EA.

Expression of CD68 and macrophage chemoattractant protein-1 genes in human adipose and muscle tissues: association with cytokine expression, insulin resistance, and reduction by pioglitazone.

To examine the role of adipose-resident macrophages in insulin resistance, we examined the gene expression of CD68, a macrophage marker, along with macrophage chemoattractant protein-1 (MCP-1) in human subcutaneous adipose tissue using real-time RT-PCR. Both CD68 and MCP-1 mRNAs were expressed in human adipose tissue, primarily in the stromal vascular fraction. When measured in the adipose tissue from subjects with normal glucose tolerance, covering a wide range of BMI (21-51 kg/m2) and insulin sensitivity (S(I)) (0.

Wnt10b deficiency promotes coexpression of myogenic and adipogenic programs in myoblasts.

Adult myoblasts retain plasticity in developmental potential and can be induced to undergo myogenic, adipogenic, or osteoblastogenic differentiation in vitro. In this report, we show that the balance between myogenic and adipogenic potential in myoblasts is controlled by Wnt signaling. Furthermore, this balance is altered during aging such that aspects of both differentiation programs are coexpressed in myoblasts due to decreased Wnt10b abundance.