The High Resolution K600 Spectrometer

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

Flat histogram simulation of lattice polymer systems

We demonstrate the use of a new algorithm called the Flat Histogram sampling algorithm for the simulation of lattice polymer systems. Thermodynamics properties, such as average energy or entropy and other physical quantities such as end-to-end distance or radius of gyration can be easily calculated using this method. Ground-state energy can also be determined. We also explore the accuracy and limitations of this method. Key words: Monte Carlo algorithms, flat histogram sampling, HP model, lattice polymer systemsComment: 7 RevTeX two-column page

Delineating the phenotypic spectrum of Bainbridge-Ropers syndrome: 12 new patients with de novo, heterozygous, loss-of-function mutations in ASXL3 and review of published literature

BACKGROUND: Bainbridge-Ropers syndrome (BRPS) is a recently described developmental disorder caused by de novo truncating mutations in the additional sex combs like 3 (ASXL3) gene. To date, there have been fewer than 10 reported patients. OBJECTIVES: Here, we delineate the BRPS phenotype further by describing a series of 12 previously unreported patients identified by the Deciphering Developmental Disorders study. METHODS: Trio-based exome sequencing was performed on all 12 patients included in this study, which found a de novo truncating mutation in ASXL3. Detailed phenotypic information and patient images were collected and summarised as part of this study. RESULTS: By obtaining genotype:phenotype data, we have been able to demonstrate a second mutation cluster region within ASXL3. This report expands the phenotype of older patients with BRPS; common emerging features include severe intellectual disability (12/12), poor/ absent speech (12/12), autistic traits (9/12), distinct face (arched eyebrows, prominent forehead, high-arched palate, hypertelorism and downslanting palpebral fissures), (9/12), hypotonia (12/12) and significant feeding difficulties (12) when young. DISCUSSION: Similarities in the patients reported previously in comparison with this cohort included their distinctive craniofacial features, feeding problems, absent/limited speech and intellectual disability. Shared behavioural phenotypes include autistic traits, hand-flapping, rocking, aggressive behaviour and sleep disturbance. CONCLUSIONS: This series expands the phenotypic spectrum of this severe disorder and highlights its surprisingly high frequency. With the advent of advanced genomic screening, we are likely to identify more variants in this gene presenting with a variable phenotype, which this study will explore

Topologically Massive Gravity and the AdS/CFT Correspondence

We set up the AdS/CFT correspondence for topologically massive gravity (TMG) in three dimensions. The first step in this procedure is to determine the appropriate fall off conditions at infinity. These cannot be fixed a priori as they depend on the bulk theory under consideration and are derived by solving asymptotically the non-linear field equations. We discuss in detail the asymptotic structure of the field equations for TMG, showing that it contains leading and subleading logarithms, determine the map between bulk fields and CFT operators, obtain the appropriate counterterms needed for holographic renormalization and compute holographically one- and two-point functions at and away from the 'chiral point' (mu = 1). The 2-point functions at the chiral point are those of a logarithmic CFT (LCFT) with c_L = 0, c_R = 3l/G_N and b = -3l/G_N, where b is a parameter characterizing different c = 0 LCFTs. The bulk correlators away from the chiral point (mu \neq 1) smoothly limit to the LCFT ones as mu \to 1. Away from the chiral point, the CFT contains a state of negative norm and the expectation value of the energy momentum tensor in that state is also negative, reflecting a corresponding bulk instability due to negative energy modes.Comment: 54 pages, v2: added comments and reference

Political stringency, infection rates, and higher education students' adherence to government measures in the Nordic countries and the UK during the first wave of the COVID-19 outbreak

Understanding predictors of adherence to governmental measures to prevent the spread of the COVID-19 is fundamental to guide health communication. This study examined whether political stringency and infection rates during the first wave of the pandemic were associated with higher education students' adherence to COVID-19 government measures in the Nordic countries (Denmark, Finland, Norway, Iceland, and Sweden) and the United Kingdom. Both individual- and country-level data were used in present study. An international cross-sectionalsubsample (n = 10,345) of higher-education students was conducted in May–June 2020 to collect individual-level information on socio-demographics, study information, living arrangements, health behaviors, stress, and COVID-19-related concerns, including adherence to government measures. Country-level data on political stringency from the Oxford COVID-19 Government Response Tracker and national infection rates were added to individual-level data. Multiple linear regression analyses stratified by country were conducted. Around 66% of students reported adhering to government measures, with the highest adherence in the UK (73%) followed by Iceland (72%), Denmark (69%), Norway (67%), Finland (64%) and Sweden (49%). Main predictors for higher adherence were older age, being femaleand being worried about getting infected with COVID-19 (individual-level), an increase in number of days since lockdown, political stringency, and information about COVID-19 mortality rates (country-level). However, incidence rate was an inconsistent predictor, which may be explained by imperfect data quality during the onset of the pandemic. We conclude that shorter lockdown periods and political stringency are associated with adherence to government measures among higher education students at the outset of the COVID-19 pandemic.Peer reviewe

Spectra of complex networks

We propose a general approach to the description of spectra of complex networks. For the spectra of networks with uncorrelated vertices (and a local tree-like structure), exact equations are derived. These equations are generalized to the case of networks with correlations between neighboring vertices. The tail of the density of eigenvalues $\rho(\lambda)$ at large $|\lambda|$ is related to the behavior of the vertex degree distribution $P(k)$ at large $k$. In particular, as $P(k) \sim k^{-\gamma}$, $\rho(\lambda) \sim |\lambda|^{1-2\gamma}$. We propose a simple approximation, which enables us to calculate spectra of various graphs analytically. We analyse spectra of various complex networks and discuss the role of vertices of low degree. We show that spectra of locally tree-like random graphs may serve as a starting point in the analysis of spectral properties of real-world networks, e.g., of the Internet.Comment: 10 pages, 4 figure

Systemic Delivery of Oncolytic Adenoviruses Targeting Transforming Growth Factor-β Inhibits Established Bone Metastasis in a Prostate Cancer Mouse Model

Abstract We have examined whether Ad.sT?RFc and TAd.sT?RFc, two oncolytic viruses expressing soluble transforming growth factor-? receptor II fused with human Fc (sTGF?RIIFc), can be developed to treat bone metastasis of prostate cancer. Incubation of PC-3 and DU-145 prostate tumor cells with Ad.sT?RFc and TAd.sT?RFc produced sTGF?RIIFc and viral replication; sTGF?RIIFc caused inhibition of TGF-?-mediated SMAD2 and SMAD3 phosphorylation. Ad(E1-).sT?RFc, an E1? adenovirus, produced sTGF?RIIFc but failed to replicate in tumor cells. To examine the antitumor response of adenoviral vectors, PC-3-luc cells were injected into the left heart ventricle of nude mice. On day 9, mice were subjected to whole-body bioluminescence imaging (BLI). Mice bearing hind-limb tumors were administered viral vectors via the tail vein on days 10, 13, and 17 (2.5?1010 viral particles per injection per mouse, each injection in a 0.1-ml volume), and subjected to BLI and X-ray radiography weekly until day 53. Ad.sT?RFc, TAd.sT?RFc, and Ad(E1-).sT?RFc caused significant inhibition of tumor growth; however, Ad.sT?RFc was the most effective among all the vectors. Only Ad.sT?RFc and TAd.sT?RFc inhibited tumor-induced hypercalcemia. Histomorphometric and synchrotron micro-computed tomographic analysis of isolated bones indicated that Ad.sT?RFc induced significant reduction in tumor burden, osteoclast number, and trabecular and cortical bone destruction. These studies suggest that Ad.sT?RFc and TAd.sT?RFc can be developed as potential new therapies for prostate cancer bone metastasis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98454/1/hum%2E2012%2E040.pd

Experimental Facilities Development

This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440

Crossovers in Unitary Fermi Systems

Universality and crossover is described for attractive and repulsive interactions where, respectively, the BCS-BEC crossover takes place and a ferromagnetic phase transition is claimed. Crossovers are also described for optical lattices and multicomponent systems. The crossovers, universal parameters and phase transitions are described within the Leggett and NSR models and calculated in detail within the Jastrow-Slater approximation. The physics of ultracold Fermi atoms is applied to neutron, nuclear and quark matter, nuclei and electrons in solids whenever possible. Specifically, the differences between optical lattices and cuprates is discussed w.r.t. antiferromagnetic, d-wave superfluid phases and phase separation.Comment: 50 pages, 15 figures. Contribution to Lecture Notes in Physics "BCS-BEC crossover and the Unitary Fermi Gas" edited by W. Zwerge

Endothelial and Inflammation Biomarker Profiles at Diagnosis Reflecting Clinical Heterogeneity and Serving as a Prognostic Tool For Treatment Response in Two Independent Cohorts of Patients With Juvenile Dermatomyositis

Objective: Juvenile dermatomyositis (DM) is a heterogeneous systemic immune-mediated vasculopathy. This study was undertaken to 1) identify inflammation/endothelial dysfunction–related biomarker profiles reflecting disease severity at diagnosis, and 2) establish whether such biomarker profiles could be used for predicting the response to treatment in patients with juvenile DM. Methods: In total, 39 biomarkers related to activation of endothelial