Diffusion of Point Defects in Two-Dimensional Colloidal Crystals

We report the first study of the dynamics of point defects, mono and di-vacancies, in a confined 2-D colloidal crystal in real space and time using digital video microscopy. The defects are introduced by manipulating individual particles with optical tweezers. The diffusion rates are measured to be $D_{mono}/a^{2}\cong3.27\pm0.03$Hz for mono-vacancies and $D_{di}/a^{2}\cong3.71\pm0.03$Hz for di-vacancies. The elementary diffusion processes are identified and it is found that the diffusion of di-vacancies is enhanced by a \textit{dislocation dissociation-recombination} mechanism. Furthermore, the defects do not follow a simple random walk but their hopping exhibits memory effects, due to the reduced symmetry (compared to the triangular lattice) of their stable configurations, and the slow relaxation rates of the lattice modes.Comment: 6 pages (REVTEX), 5 figures (PS

BIS monitoring versus clinical assessment for sedation in mechanically ventilated adults in the intensive care unit and its impact on clinical outcomes and resource utilization.

BACKGROUND: Patients admitted to intensive care and on mechanical ventilation, are administered sedative and analgesic drugs to improve both their comfort and interaction with the ventilator. Optimizing sedation practice may reduce mortality, improve patient comfort and reduce cost. Current practice is to use scales or scores to assess depth of sedation based on clinical criteria such as consciousness, understanding and response to commands. However these are perceived as subjective assessment tools. Bispectral index (BIS) monitors, which are based on the processing of electroencephalographic signals, may overcome the restraints of the sedation scales and provide a more reliable and consistent guidance for the titration of sedation depth.The benefits of BIS monitoring of patients under general anaesthesia for surgical procedures have already been confirmed by another Cochrane review. By undertaking a well-conducted systematic review our aim was to find out if BIS monitoring improves outcomes in mechanically ventilated adult intensive care unit (ICU) patients. OBJECTIVES: To assess the effects of BIS monitoring compared with clinical sedation assessment on ICU length of stay (LOS), duration of mechanical ventilation, any cause mortality, risk of ventilator-associated pneumonia (VAP), risk of adverse events (e.g. self-extubation, unplanned disconnection of indwelling catheters), hospital LOS, amount of sedative agents used, cost, longer-term functional outcomes and quality of life as reported by authors for mechanically ventilated adults in the ICU. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, CINAHL, ProQuest, OpenGrey and SciSearch up to May 2017 and checked references citation searching and contacted study authors to identify additional studies. We searched trial registries, which included clinicaltrials.gov and controlled-trials.com. SELECTION CRITERIA: We included all randomized controlled trials comparing BIS versus clinical assessment (CA) for the management of sedation in mechanically ventilated critically ill adults. DATA COLLECTION AND ANALYSIS: We used Cochrane's standard methodological procedures. We undertook analysis using Revman 5.3 software. MAIN RESULTS: We identified 4245 possible studies from the initial search. Of those studies, four studies (256 participants) met the inclusion criteria. One more study is awaiting classification. Studies were, conducted in single-centre surgical and mixed medical-surgical ICUs. BIS monitor was used to assess the level of sedation in the intervention arm in all the studies. In the control arm, the sedation assessment tools for CA included the Sedation-Agitation Scale (SAS), Ramsay Sedation Scale (RSS) or subjective CA utilizing traditional clinical signs (heart rate, blood pressure, conscious level and pupillary size). Only one study was classified as low risk of bias, the other three studies were classified as high risk.There was no evidence of a difference in one study (N = 50) that measured ICU LOS (Median (Interquartile Range IQR) 8 (4 to 14) in the CA group; 12 (6 to 18) in the BIS group; low-quality evidence).There was little or no effect on the duration of mechanical ventilation (MD -0.02 days (95% CI -0.13 to 0.09; 2 studies; N = 155; I2 = 0%; low-quality evidence)). Adverse events were reported in one study (N = 105) and the effects on restlessness after suction, endotracheal tube resistance, pain tolerance during sedation or delirium after extubation were uncertain due to very low-quality evidence. Clinically relevant adverse events such as self-extubation were not reported in any study. Three studies reported the amount of sedative agents used. We could not measure combined difference in the amount of sedative agents used because of different sedation protocols and sedative agents used in the studies. GRADE quality of evidence was very low. No study reported other secondary outcomes of interest for the review. AUTHORS' CONCLUSIONS: We found insufficient evidence about the effects of BIS monitoring for sedation in critically ill mechanically ventilated adults on clinical outcomes or resource utilization. The findings are uncertain due to the low- and very low-quality evidence derived from a limited number of studies

Capacitated Center Problems with Two-Sided Bounds and Outliers

In recent years, the capacitated center problems have attracted a lot of research interest. Given a set of vertices $V$, we want to find a subset of vertices $S$, called centers, such that the maximum cluster radius is minimized. Moreover, each center in $S$ should satisfy some capacity constraint, which could be an upper or lower bound on the number of vertices it can serve. Capacitated $k$-center problems with one-sided bounds (upper or lower) have been well studied in previous work, and a constant factor approximation was obtained. We are the first to study the capacitated center problem with both capacity lower and upper bounds (with or without outliers). We assume each vertex has a uniform lower bound and a non-uniform upper bound. For the case of opening exactly $k$ centers, we note that a generalization of a recent LP approach can achieve constant factor approximation algorithms for our problems. Our main contribution is a simple combinatorial algorithm for the case where there is no cardinality constraint on the number of open centers. Our combinatorial algorithm is simpler and achieves better constant approximation factor compared to the LP approach

Allele mining in β-lactoglobulin gene of Capra hircus

β-Lactoglobulin (β-LG) genetic polymorphisms are important and well known due to their effects on quantitative traits and technological properties of milk. At the DNA level, polymerase chain reaction (PCR)-single-strand conformation polymorphism (SSCP) allows for the detection of unknown polymorphisms at β-LG loci. Here we describe the usefulness of the PCR-SSCP technique for β-LG typing. In the present study, we amplified and sequenced the part of promoter region and all the seven exons containing the entire coding and untranslated region for the β-lactoglobulin gene in best dairy goat breeds of India namely: Jamunapari and Jakhrana. Nine polymorphisms were detected, one in the l promoter region, four in the introns and four in the exons of the β-lactoglobulin gene. All polymorphisms were single nucleotide substitutions. The polymorphisms in the coding region did not produce any amino acid change.Key words: β-Lactoglobulin gene, dairy goats, polymorphism, single nucleotide polymorphism (SNP), single strand conformational polymorphism (SSCP)

Approximating k-Forest with Resource Augmentation: A Primal-Dual Approach

In this paper, we study the $k$-forest problem in the model of resource augmentation. In the $k$-forest problem, given an edge-weighted graph $G(V,E)$, a parameter $k$, and a set of $m$ demand pairs $\subseteq V \times V$, the objective is to construct a minimum-cost subgraph that connects at least $k$ demands. The problem is hard to approximate---the best-known approximation ratio is $O(\min\{\sqrt{n}, \sqrt{k}\})$. Furthermore, $k$-forest is as hard to approximate as the notoriously-hard densest $k$-subgraph problem. While the $k$-forest problem is hard to approximate in the worst-case, we show that with the use of resource augmentation, we can efficiently approximate it up to a constant factor. First, we restate the problem in terms of the number of demands that are {\em not} connected. In particular, the objective of the $k$-forest problem can be viewed as to remove at most $m-k$ demands and find a minimum-cost subgraph that connects the remaining demands. We use this perspective of the problem to explain the performance of our algorithm (in terms of the augmentation) in a more intuitive way. Specifically, we present a polynomial-time algorithm for the $k$-forest problem that, for every $\epsilon>0$, removes at most $m-k$ demands and has cost no more than $O(1/\epsilon^{2})$ times the cost of an optimal algorithm that removes at most $(1-\epsilon)(m-k)$ demands

Asymmetry to symmetry transition of Fano line-shape: Analytical derivation

An analytical derivation of Fano line-shape asymmetry ratio has been presented here for a general case. It is shown that Fano line-shape becomes less asymmetric as \q is increased and finally becomes completely symmetric in the limiting condition of q equal to infinity. Asymmetry ratios of Fano line-shapes have been calculated and are found to be in good consonance with the reported expressions for asymmetry ratio as a function of Fano parameter. Application of this derivation is also mentioned for explanation of asymmetry to symmetry transition of Fano line-shape in quantum confined silicon nanostructures.Comment: 3 figures, Latex files, Theoretica

High-Resolution Sonography: A New Technique to Detect Nerve Damage in Leprosy

Mycobacterium leprae, which causes leprosy, infects peripheral nerves resulting in functional impairment, ulcer formation and stigmatizing deformities. Early diagnosis of nerve involvement is important to avoid nerve related complications. We used non-invasive, high-resolution sonography (US) and color Doppler (CD) imaging to study the ulnar (UN), median (MN), lateral popliteal (LP) and posterior tibial (PT) nerves in 20 leprosy patients and compared 30 healthy Indian controls. The nerves were significantly thicker in the patients (p<0.0001 for each nerve). One of the key signs of leprosy is the presence of enlarged nerves. The kappa for clinical palpation and nerve enlargement by sonography was 0.30 for all examined nerves. Increased neural vascularity, the sign of inflammation was observed in 26% (39/152) of nerves by CD imaging. Increased CD was observed in multiple nerves in 3 of 4 patients with type 2 reaction. Significant correlation was observed between clinical parameters of grade of thickening, sensory loss and muscle weakness and US abnormalities of nerve echotexture, endoneural flow and cross-sectional area (p<0.001). We conclude that sonography is a better diagnostic tool to predict nerve damage as compared to clinical assessment. Nerve damage was sonographically more extensive and was observed in nerves considered clinically normal

Peptide-MHC Cellular Microarray with Innovative Data Analysis System for Simultaneously Detecting Multiple CD4 T-Cell Responses

Peptide:MHC cellular microarrays have been proposed to simultaneously characterize multiple Ag-specific populations of T cells. The practice of studying immune responses to complicated pathogens with this tool demands extensive knowledge of T cell epitopes and the availability of peptide:MHC complexes for array fabrication as well as a specialized data analysis approach for result interpretation. T cell cultures. A novel statistical methodology was also developed to facilitate batch processing of raw array-like data into standardized endpoint scores, which linearly correlated with total Ag-specific T cell inputs. Applying these methods to analyze Influenza A viral antigen-specific T cell responses, we not only revealed the most prominent viral epitopes, but also demonstrated the heterogeneity of anti-viral cellular responses in healthy individuals. Applying these methods to examine the insulin producing beta-cell autoantigen specific T cell responses, we observed little difference between autoimmune diabetic patients and healthy individuals, suggesting a more subtle association between diabetes status and peripheral autoreactive T cells.The data analysis system is reliable for T cell specificity and functional testing. Peptide:MHC cellular microarrays can be used to obtain multi-parametric results using limited blood samples in a variety of translational settings