Searching for Extra Dimensions in the Early Universe

We investigate extra spatial dimensions ($D = 3+\epsilon$) in the early universe using very high resolution molecular rotational spectroscopic data derived from a large molecular cloud containing moderately cold carbon monoxide gas at Z $\approx 6.42$. It turns out that the $\epsilon$-dependent quantum mechanical wavelength transitions are solvable for a linear molecule and we present the solution here. The CO microwave data allows a very precise determination of $= -0.00000657 \pm .10003032$. The probability that $\neq 0$ is one in 7794, only 850 million years (using the standard cosmology) after the Big Bang.Comment: 17 pages, 2 figure

On the Study of Collective Dynamics in Supercooled Liquids through the Statistics of the Iso-Configurational Ensemble

The use of the isoconfigurational ensemble to explore structure-dynamic correlations in supercooled liquids is examined. The statistical error of the dynamic propensity and its spatial distribution are determined. The authors present the spatial distribution of the particle non-Gaussian parameter as a measure of the intermittency with which particles exhibit their propensity for motion. The ensemble average of the direction of particle motion is introduced to establish the anisotropy of the dynamic propensity.Comment: Published - see below or http://link.aip.org/link/?JCPSA6/126/154503/

Power aspects of analysis of variance in various models.

The object of the present work is to study the robustness of the power in Analysis of Variance in relation to the departures from the in-built assumptions (i) equality of variance of the errors, (ii) statistical independence of the errors, and (iii) normality of the errors in fixed and random effects models. It is difficult if not impossible, to conduct an exhaustive study of the problem, because the above assumptions can be violated in many ways. However, a general model and some important particular models have been used to obtain fairly conclusive evidence regarding the robustness of the power in Analysis of Variance. In order to obtain the power value in relation to the departure from the usual test assumptions, the general linear hypothesis model is considered. The power values when the assumptions of equality of variances and independence of errors are violated, are obtained and presented in Table IA and IB. The result suggests that in the above model, for tests regarding the inference about means, the power value is greatly affected by the inequality of error variances but only slightly affected by the serially correlated error variables. By using the permutation theory an approximate method is developed to study the effect of non-normality of the errors on the probability of type two errors in the above situation. Having studied the most general case in Analysis of Variance some particular models are discussed to investigate certain important aspects of the problem that are generated by these models. First of all fixed model one-way classification is considered to investigate whether it could show a different picture for unequal replication. The results so obtained are presented in Table IIA and IIB. They indicate that the power value is greatly affected by the inequality of error variances and unequal group sizes. This procedure is easily modified to handle the random model. Another particular case of the general linear model, that is fixed effect model two-way classification, is discussed. The results so obtained are presented in Table IIIA and IIIB. They indicate that in two-way classification for the between Column test, the power value is greatly affected by the inequality of column variances but only slightly affected by the serially correlated within rows error variables. Again this procedure is easily modified to handle the random model. The use of simulation methods for calculating the power values in the case of non-normal errors is discussed. One and two-way classifications are considered for the fixed effect model. The Erlangian and contaminated normal distribution are taken as examples of a non-normal error distribution. The results obtained by these methods are given in Table IVA and IVB which indicate that for the inference concerning means, the power calculated under normal theory is only slightly affected by the non-normality of the errors. Finally, the effect of non-normality on the power in analysis of variance for a random effect model is also discussed by a simulation method. One and two-way classification are considered for this model and the Erlangian and contaminated normal distributions are taken as examples of non-normality. The results obtained by these methods are given in Tables VA and VB which indicate that non-normality has little effect on the power of the test

Fitting a non-linear model with errors in both variables and its application

Estimation of the parameters of a non-linear model is considered when both measured variables have random errors. The maximum likelihood estimates with the asymptotic variance and covariance matrix are presented. Real data are used to illustrate the procedure discusse

The analytic hierarchy process to support decision-making processes in infrastructure projects with social impact

There is an increasing awareness among all kinds of organisations (in business,government and civil society) about the benefits of jointly working with stakeholders to satisfy both their goals and the social demands placed upon them. This is particularly the case within corporate social responsibility (CSR) frameworks. In this regard, multi-criteria tools for decision-making like the analytic hierarchy process (AHP) described in the paper can be useful for the building relationships with stakeholders. Since these tools can reveal decision-maker’s preferences, the integration of opinions from various stakeholders in the decision-making process may result in better and more innovative solutions with significant shared value. This paper is based on ongoing research to assess the feasibility of an AHP-based model to support CSR decisions in large infrastructure projects carried out by Red Electrica de España, the sole transmission agent and operator of the Spanishelectricity system

Alternate efflux pump mechanism may contribute to drug resistance in extensively drug-resistant isolates of mycobacterium tuberculosis

INTRODUCTION: Extensively drug-resistant tuberculosis (XDR-TB) has emerged as one of the biggest threats to public health and TB control programs worldwide. XDR-TB is caused by Mycobacterium tuberculosis (MTB) strains resistant to rifampin and isoniazid, as well as to a fluoroquinolone and to at least one injectable aminoglycoside. Drug resistance in MTB has primarily been associated with single nucleotide polymorphisms (SNPs) in particular genes. However, it has also been shown that efflux pumps may play a role in resistance of MTB. Upregulation of drug efflux pumps can decrease the intracellular concentration of drugs and reduce their efficacy. METHODS: Whole genome sequencing was performed on 32 XDR-TB clinical isolates. Sequence data were used to investigate SNPs in efflux pump genes as compared with the H37Rv reference genome. RESULTS: Of the XDR MTB strains, eight (21.62%) were wild type for rpsL, rrs (500 region), and gidB genes, but had non-synonymous (ns) SNPs (aspartic acid to histidine) in the drrA efflux pump gene at position 3273138. Three of eight (37.5%) XDR MTB strains, wild type for rpsL, rrs (500 region), gidB, and gyrB genes were phenotypically streptomycin sensitive and five (62.5%) XDR MTB strains were streptomycin resistant, while all XDR MTB strains, wild type for rpsL, rrs, gidB, and gyrB genes were resistant to fluoroquinolone (ofloxacin) and ethambutol. In addition, three XDR MTB strains wild type for rpsL, rrs, gidB, and drrA genes showed nsSNPs (isoleucine to valine) in the major facilitator superfamily, Rv1634 efflux pump gene at position 1839306. CONCLUSION: Our data show an nsSNP in the drrA efflux pump gene that may result in upregulation of drug efflux mechanisms in MTB strains. It is therefore imperative to understand the mechanism of efflux and its role in drug resistance, which will enable the identification of new drug targets and development of new drug regimens to counteract the drug efflux mechanism of MTB

Datta-Das type spin-field effect transistor in non-ballistic regime

It is revealed that in spin helix state of (001) quantum well system, strong suppression of D'yakonov-Perel' spin relaxation process occurs by an interplay between Rashba and Dresselhaus couplings over a wide range of Rashba coupling strength. Contrary to common belief in early works, this leads to the finding that Datta-Das type spin-field effect transistor is actually applicable to more realistic non-ballistic transport regime in two dimensional electron gas system.Comment: 8 pages, 3 figure

Heterogeneous ice nucleation on dust particles sourced from nine deserts worldwide - Part 1: Immersion freezing

Desert dust is one of the most abundant ice nucleating particle types in the atmosphere. Traditionally, clay minerals were assumed to determine the ice nucleation ability of desert dust and constituted the focus of ice nucleation studies over several decades. Recently some feldspar species were identified to be ice active at much higher temperatures than clay minerals, redirecting studies to investigate the contribution of feldspar to ice nucleation on desert dust. However, so far no study has shown the atmospheric relevance of this mineral phase. For this study four dust samples were collected after airborne transport in the troposphere from the Sahara to different locations (Crete, the Peloponnese, Canary Islands, and the Sinai Peninsula). Additionally, 11 dust samples were collected from the surface from nine of the biggest deserts worldwide. The samples were used to study the ice nucleation behavior specific to different desert dusts. Furthermore, we investigated how representative surface-collected dust is for the atmosphere by comparing to the ice nucleation activity of the airborne samples. We used the IMCA-ZINC setup to form droplets on single aerosol particles which were subsequently exposed to temperatures between 233 and 250 K. Dust particles were collected in parallel on filters for offline cold-stage ice nucleation experiments at 253–263 K. To help the interpretation of the ice nucleation experiments the mineralogical composition of the dusts was investigated. We find that a higher ice nucleation activity in a given sample at 253 K can be attributed to the K-feldspar content present in this sample, whereas at temperatures between 238 and 245 K it is attributed to the sum of feldspar and quartz content present. A high clay content, in contrast, is associated with lower ice nucleation activity. This confirms the importance of feldspar above 250 K and the role of quartz and feldspars determining the ice nucleation activities at lower temperatures as found by earlier studies for monomineral dusts. The airborne samples show on average a lower ice nucleation activity than the surface-collected ones. Furthermore, we find that under certain conditions milling can lead to a decrease in the ice nucleation ability of polymineral samples due to the different hardness and cleavage of individual mineral phases causing an increase of minerals with low ice nucleation ability in the atmospherically relevant size fraction. Comparison of our data set to an existing desert dust parameterization confirms its applicability for climate models. Our results suggest that for an improved prediction of the ice nucleation ability of desert dust in the atmosphere, the modeling of emission and atmospheric transport of the feldspar and quartz mineral phases would be key, while other minerals are only of minor importance

Single nucleotide polymorphisms in efflux pumps genes in extensively drug resistant Mycobacterium tuberculosis isolates from Pakistan

It is challenging to understand mechanisms of drug resistance in Mycobacterium tuberculosis (MTB) due to the large variability in resistance associated genes. Efflux pump genes contribute to drug resistance and thus add to this complexity. Efflux pump gene protein superfamilies have been characterized by genome analysis of drug resistant strains and through invitro transcriptional studies. However, there is limited information regarding efflux pump genes in extensively drug resistant (XDR) tuberculosis (TB) isolates. Whole genome sequencing (WGS) based analysis of 37 extensively drug resistant (XDR) and five drug sensitive (DS) MTB clinical isolates was performed. Single nucleotide polymorphisms (SNPs) in efflux pump genes Rv0194, Rv1217, Rv1218, drrA, drrB, Rv1258, Rv1634, Rv2688, Rv1273, Rv1819, Rv1458, Rv1877 and Rv1250 were determined in the clinical isolates as compared with the H37Rv reference strain. Allele frequencies of SNPs identified in XDR strains were compared with DS strains. Gene expression of Rv0194, Rv2688, Rv1634, drrA and drrB was determined in XDR -TB isolates (n=9), DS-TB strains (n=4) and H37Rv. We identified SNPs in XDR-TB isolates which were either unique or present at very low frequencies in DS strains; Rv0194 G170V; Rv1217 L151R; Rv1258 P369T and G391R; Rv1273 S118G and I175T; Rv1877 I534T; Rv1250 V318X/A and S333A, and Rv2688 P156T. The expression of Rv2688 and drrB was found to be raised in XDR-TB as compared with DS-TB strains. We identified unique SNPs in efflux pump genes which may be associated with increased drug resistance in the isolates. Increased levels of Rv2688 and drrB efflux pump gene expression observed in XDR strains even in the absence of antibiotics suggests that these clinical isolates may be more refractory to treatment. Further studies are required to directly associate these mutations with increased resistance in MTB

Characterization of genomic variations in SNPs of PE_PGRS genes reveals deletions and insertions in extensively drug resistant (XDR) M. tuberculosis strains from Pakistan.

BACKGROUND: Mycobacterium tuberculosis (MTB) PE_PGRS genes belong to the PE multigene family. Although the function of PE_PGRS genes is unknown, it is hypothesized that the PE_PGRS genes may be associated with antigenic variability in MTB. MATERIAL AND METHODS: Whole genome sequencing analysis was performed on (n=37) extensively drug-resistant (XDR) MTB strains from Pakistan, which included Lineage 1 (East African Indian, n=2); Other lineage 1 (n=3); Lineage 3 (Central Asian, n=24); Other lineage 3 (n=4); Lineage 4 (X3, n=1) and T group (n=3) MTB strains. RESULTS: There were 107 SNPs identified from the analysis of 42 PE_PGRS genes; of these, 13 were non-synonymous SNPs (nsSNPs). The nsSNPs identified in PE_PGRS genes - 6, 9 and 10 - were common in all EAI, CAS, Other lineages (1 and 3), T1 and X3. Deletions (DELs) in PE_PGRS genes - 3 and 19 - were observed in 17 (80.9%) CAS1 and 6 (85.7%) in Other lineages (1 and 3) XDR MTB strains, while DELs in the PE_PGRS49 were observed in all CAS1, CAS, CAS2 and Other lineages (1 and 3) XDR MTB strains. All CAS, EAI and Other lineages (1 and 3) strains showed insertions (INS) in PE_PGRS6 gene, while INS in the PE_PGRSgenes 19 and 33 were observed in 20 (95.2%) CAS1, all CAS, CAS2, EAI and Other lineages (1 and 3) XDR MTB strains. CONCLUSION: Genetic diversity in PE_PGRS genes contributes to antigenic variability and may result in increased immunogenicity of strains. This is the first study identifying variations in nsSNPs and INDELs in the PE_PGRS genes of XDR-TB strains from Pakistan. It highlights common genetic variations which may contribute to persistence