A new portable 3-D gyroscope system for the evaluation of upper limb function

This study aims to develop a lightweight, portable and cost effective system for 3D motion analysis of the upper limb which can be readily applied within a clinical environment

A conserved metalloprotease mediates ecdysis in Caenorhabditis elegans

Molting is required for progression between larval stages in the life cycle of nematodes. We have identified four mutant alleles of a <i>Caenorhabditis elegans</i> metalloprotease gene, <i>nas-37</i>, that cause incomplete ecdysis. At each molt the cuticle fails to open sufficiently at the anterior end and the partially shed cuticle is dragged behind the animal. The gene is expressed in hypodermal cells 4 hours before ecdysis during all larval stages. The <i>NAS-37</i> protein accumulates in the anterior cuticle and is shed in the cuticle after ecdysis. This pattern of protein accumulation places NAS- 37 in the right place and at the right time to degrade the cuticle to facilitate ecdysis. The nas-37 gene has orthologs in other nematode species, including parasitic nematodes, and they undergo a similar shedding process. For example, <i>Haemonchus contortus</i> molts by digesting a ring of cuticle at the tip of the nose. Incubating <i>Haemonchus</i> larvae in extracted exsheathing fluids causes a refractile ring of digested cuticle to form at the tip of the nose. When <i>Haemonchus</i> cuticles are incubated with purified NAS-37, a similar refractile ring forms. NAS-37 degradation of the <i>Haemonchus</i> cuticle suggests that the metalloproteases and the cuticle substrates involved in exsheathment of parasitic nematodes are conserved in free-living nematodes

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

Optical Properties of Heavily Fluorinated Lanthanide Tris β-Diketonate Phosphine Oxide Adducts

The construction of lanthanide(III) chelates that exhibit superior photophysical properties holds great importance in biological and materials science. One strategy to increase the luminescence properties of lanthanide(III) chelates is to hinder competitive non-radiative decay processes through perfluorination of the chelating ligands. Here, the synthesis of two families of heavily fluorinated lanthanide(III) β-diketonate complexes bearing monodentate perfluorinated tris phenyl phosphine oxide ligands have been prepared through a facile one pot reaction [Ln(hfac)3{(ArF)3PO}(H2O)] and [Ln(F7-acac)3{(ArF)3PO}2] (where Ln = Sm3+, Eu3+, Tb3+, Er3+ and Yb3+). Single crystal X-ray diffraction analysis in combination with photophysical studies have been performed to investigate the factors responsible for the differences in the luminescence lifetimes and intrinsic quantum yields of the complexes. Replacement of both bound H2O and C–H oscillators in the ligand backbone has a dramatic effect on the photophysical properties of the complexes, particularly for the near infra-red emitting ion Yb3+, where a five fold increase in luminescence lifetime and quantum yield is observed. The complexes [Sm(hfac)3{(ArF)3PO}(H2O)] (1), [Yb(hfac)3{(ArF)3PO}(H2O)] (5), [Sm(F7-acac)3{(ArF)3PO}2] (6) and [Yb(F7-acac)3{(ArF)3PO}2] (10) exhibit unusually long luminescence lifetimes and attractive intrinsic quantum yields of emission in fluid solution (ΦLn = 3.4% (1); 1.4% (10)) and in the solid state (ΦLn = 8.5% (1); 2.0% (5); 26% (6); 11% (10)), which are amongst the largest values for this class of compounds to date

A second look at the toric h-polynomial of a cubical complex

We provide an explicit formula for the toric $h$-contribution of each cubical shelling component, and a new combinatorial model to prove Clara Chan's result on the non-negativity of these contributions. Our model allows for a variant of the Gessel-Shapiro result on the $g$-polynomial of the cubical lattice, this variant may be shown by simple inclusion-exclusion. We establish an isomorphism between our model and Chan's model and provide a reinterpretation in terms of noncrossing partitions. By discovering another variant of the Gessel-Shapiro result in the work of Denise and Simion, we find evidence that the toric $h$-polynomials of cubes are related to the Morgan-Voyce polynomials via Viennot's combinatorial theory of orthogonal polynomials.Comment: Minor correction

Necrotising Fasciitis of the Lower Limb caused by Community-Acquired Methicillin-Resistant Staphylococcus aureus

Necrotising fasciitis caused by Community-Acquired Methicillin-resistant Staphylococcus aureus (CA-MRSA) has emerged as a new entity. Although it is recognised worldwide, there have been no reported cases to date in Malaysia. We report a case of necrotising fasciitis of the left lower limb in an otherwise healthy 20-year-old man. He presented with septic shock and despite the paucity of clinical signs in the limb, the infection was aggressive. Methicillin-Resistant Staphylococcus aureus (MRSA) was isolated from the deep fascia of the leg. Panton-Valentine leucocidin gene (PVL), which is a stable genetic marker for CA-MRSA strain, was positive in this case. This case of community acquired MRSA necrotising fasciitis is of concern and may herald the emergence of this resistant organism in Malaysia. Vigilant surveillance and microbiological monitoring is needed to follow this CAMRSA trend

Thermodynamics and Kinetic Theory of Relativistic Gases in 2-D Cosmological Models

A kinetic theory of relativistic gases in a two-dimensional space is developed in order to obtain the equilibrium distribution function and the expressions for the fields of energy per particle, pressure, entropy per particle and heat capacities in equilibrium. Furthermore, by using the method of Chapman and Enskog for a kinetic model of the Boltzmann equation the non-equilibrium energy-momentum tensor and the entropy production rate are determined for a universe described by a two-dimensional Robertson-Walker metric. The solutions of the gravitational field equations that consider the non-equilibrium energy-momentum tensor - associated with the coefficient of bulk viscosity - show that opposed to the four-dimensional case, the cosmic scale factor attains a maximum value at a finite time decreasing to a "big crunch" and that there exists a solution of the gravitational field equations corresponding to a "false vacuum". The evolution of the fields of pressure, energy density and entropy production rate with the time is also discussed.Comment: 23 pages, accepted in PR

Neural signals predict information sharing across cultures

Information sharing influences which messages spread and shape beliefs, behavior, and culture. In a preregistered neuroimaging study conducted in the United States and the Netherlands, we demonstrate replicability, predictive validity, and generalizability of a brain-based prediction model of information sharing. Replicating findings in Scholz et al., Proc. Natl. Acad. Sci. U.S.A. 114, 2881–2886 (2017), self-, social-, and value-related neural signals in a group of individuals tracked the population sharing of US news articles. Preregistered brain-based prediction models trained on Scholz et al. (2017) data proved generalizable to the new data, explaining more variance in population sharing than self-report ratings alone. Neural signals (versus self-reports) more reliably predicted sharing cross-culturally, suggesting that they capture more universal psychological mechanisms underlying sharing behavior. These findings highlight key neurocognitive foundations of sharing, suggest potential target mechanisms for interventions to increase message effectiveness, and advance brain-as-predictor research

Universal Correlations of Coulomb Blockade Conductance Peaks and the Rotation Scaling in Quantum Dots

We show that the parametric correlations of the conductance peak amplitudes of a chaotic or weakly disordered quantum dot in the Coulomb blockade regime become universal upon an appropriate scaling of the parameter. We compute the universal forms of this correlator for both cases of conserved and broken time reversal symmetry. For a symmetric dot the correlator is independent of the details in each lead such as the number of channels and their correlation. We derive a new scaling, which we call the rotation scaling, that can be computed directly from the dot's eigenfunction rotation rate or alternatively from the conductance peak heights, and therefore does not require knowledge of the spectrum of the dot. The relation of the rotation scaling to the level velocity scaling is discussed. The exact analytic form of the conductance peak correlator is derived at short distances. We also calculate the universal distributions of the average level width velocity for various values of the scaled parameter. The universality is illustrated in an Anderson model of a disordered dot.Comment: 35 pages, RevTex, 6 Postscript figure