Detection of a quantum particle on a lattice under repeated projective measurements

We consider a quantum particle, moving on a lattice with a tight-binding Hamiltonian, which is subjected to measurements to detect it's arrival at a particular chosen set of sites. The projective measurements are made at regular time intervals $\tau$, and we consider the evolution of the wave function till the time a detection occurs. We study the probabilities of its first detection at some time and conversely the probability of it not being detected (i.e., surviving) up to that time. We propose a general perturbative approach for understanding the dynamics which maps the evolution operator, consisting of unitary transformations followed by projections, to one described by a non-Hermitian Hamiltonian. For some examples, of a particle moving on one and two-dimensional lattices with one or more detection sites, we use this approach to find exact expressions for the survival probability and find excellent agreement with direct numerical results. A mean field model with hopping between all pairs of sites and detection at one site is solved exactly. For the one- and two-dimensional systems, the survival probability is shown to have a power-law decay with time, where the power depends on the initial position of the particle. Finally, we show an interesting and non-trivial connection between the dynamics of the particle in our model and the evolution of a particle under a non-Hermitian Hamiltonian with a large absorbing potential at some sites.Comment: 11 pages, 6 figure

<i style="mso-bidi-font-style:normal"><span style="font-size:11.0pt;font-family:"Times New Roman";mso-fareast-font-family: "Times New Roman";mso-bidi-font-family:Mangal;mso-ansi-language:EN-GB; mso-fareast-language:EN-US;mso-bidi-language:HI" lang="EN-GB">In silico</span></i><span style="font-size:11.0pt;font-family:"Times New Roman";mso-fareast-font-family: "Times New Roman";mso-bidi-font-family:Mangal;mso-ansi-language:EN-GB; mso-fareast-language:EN-US;mso-bidi-language:HI" lang="EN-GB"> analysis reveals the role of horizontally transferred genes (HGTs) in shaping the pathogenicity of <i style="mso-bidi-font-style:normal">Xanthomonas</i></span>

404-411The role of <i style="mso-bidi-font-style: normal">Xanthomonas spp. as phytopathogen has been well recognized in diseases of important crops like rice, canola, tomato, citrus, etc. The genomes of a number of Xanthomonas strains are also fully sequenced and they are made available in various data bases. In the present study, in silico analysis of six Xanthomonas genomes was carried out. Synonymous codon usage pattern study in these genomes revealed that pathogenicity related (PR)-horizontally transferred genes (HGTs) were, in general, expressed lowly and were less biased in comparison with average protein coding genes and ribosomal protein genes. Moreover, the correspondence analysis showed that the ribosomal genes were clustered at one end, while the HGTs and the PR-HGTs were all scattered. It has been also revealed that how the virulent HGTs, in spite of having low expression levels, did enhance the pathogenicity of the Xanthomonas strains to certain extent by targeting important cellular functions

In silico analysis reveals the role of horizontally transferred genes (HGTs) in shaping the pathogenicity of Xanthomonas

The role of Xanthomonas spp. as phytopathogen has been well recognized in diseases of important crops like rice, canola, tomato, citrus, etc. The genomes of a number of Xanthomonas strains are also fully sequenced and they are made available in various data bases. In the present study, in silico analysis of six Xanthomonas genomes was carried out. Synonymous codon usage pattern study in these genomes revealed that pathogenicity related (PR)-horizontally transferred genes (HGTs) were, in general, expressed lowly and were less biased in comparison with average protein coding genes and ribosomal protein genes. Moreover, the correspondence analysis showed that the ribosomal genes were clustered at one end, while the HGTs and the PR-HGTs were all scattered. It has been also revealed that how the virulent HGTs, in spite of having low expression levels, did enhance the pathogenicity of the Xanthomonas strains to certain extent by targeting important cellular functions

Role of community group exposure in reducing sexually transmitted infection-related risk among female sex workers in India

Background: Empowering female sex workers (FSWs) to address structural barriers and forming community groups (CGs) through community mobilization are seen as essential components of HIV prevention programs in India. Taking the membership of a CG as an exposure intervention, we hypothesized whether participation in a CG lead to reduced sexually transmitted infections (STIs) and increased treatment-seeking behavior among FSWs in three selected states of India — Andhra Pradesh, Maharashtra and Tamil Nadu. Methods and Findings: The propensity score matching (PSM) approach examined the effect of CG membership, as against no membership, on STI-related risk, described as selected outcome measures — presence of any STI, self-reported STI symptoms, and treatment-seeking behavior among FSWs. A cross sectional bio-behavioral survey was administered in 2009–2010 and covered 7,806 FSWs through two-stage probability-based conventional and time location cluster sampling in 23 administrative districts of Andhra Pradesh, Maharashtra and Tamil Nadu. Only 2,939 FSWs were reported to be members of a CG and among them 4.5% had any STIs. A majority of FSWs were aged above 24 years (86.4%), had ever been married (73%), operated from a public place for solicitation (81.5%), and had ever received HIV test results (75.6%). The average effect of CG exposure was reduction in STI prevalence by 4%, while self-reported STI symptom treatment-seeking behavior increased by 13.7%. Conclusion: FSWs who were exposed to a CG were at a substantially lower risk of STIs than those who were unexposed. The FSWs exposed to a CG had a higher chance of seeking STI treatment from public and private health facilities. Collectivization related challenges must be overcome to provide access to tailored STI prevention and care services

Comparison of Sexual Risk, HIV/STI Prevalence and Intervention Exposure Among Men Who Have Sex with Men and Women (MSMW) and Men Who Have Sex with Men Only (MSMO) in India: Implications for HIV Prevention

The Author(s) 2015. This article is published with open access at Springerlink.com Abstract Using data from a cross-sectional bio-behav-ioral survey conducted among men who have sex with men (n = 3833) in India, we examined differences related to HIV-related sexual risk, HIV/STI prevalence and inter-vention exposures between men who have sex with men and women (MSMW, 35 % of the sample) and men who have sex with men only (MSMO). Among MSMW, 93 % reported having female regular partners, 14 % had female paid partners, and all types of male partners (regular 55 %; casual 77.1 %; paying 47 %; paid 19 %). Logistic regres-sion revealed that MSMW had higher odds of being aged 26 years and above (AOR 4.45, 95 % CI 3.66–5.42), lower odds of inconsistently using condoms with male partners (AOR 0.82, 95 % CI 0.67–0.98) and lower odds of having kothi (feminine/mostly receptive) identity (AOR 0.07, 95 % CI 0.06–0.09). HIV intervention exposure and HIV/ STI prevalence did not differ significantly between MSMW and MSMO (HIV 13.1 vs. 12.2 %; active syphilis 3.5 vs. 3.1 %, respectively). Concurrent sexual partnerships with men and women pose risk of HIV transmission/acquisition for MSM and their male and female partners. All sub-groups of MSM require tailored information and skills to consistently use condoms with different types of partners of either gender

Factors Associated with Use of Latex Condom-Compatible Lubricants by Men Who Have Sex with Men in India: Implications for HIV Prevention

We examined the prevalence and type of rectal lubricants use and factors associated with exclusive use of latex-condom compatible lubricants (water-based lubricants) among men who have sex with men (MSM) using data from a large-scale cross-sectional survey conducted in 2009/10 in three Indian states. Using time-location cluster sampling, 3880 MSM were recruited from cruising sites. We used multiple logistic regression to assess the association between type of lubricants used and sociodemographic and programmatic indicators. Among those who reported using lubricants (64%) more than half (53%) exclusively used water-based lubricants, less than one-tenth used exclusively oil-based lubricants, and nearly 40% used both water-based and oil-based lubricants. Factors associated with exclusive use of water-based lubricants were exposure to HIV prevention interventions (AOR: 6.18, 95% CI 4.82 to 7.92) and kothi-identified MSM—feminine/anal-receptive (AOR: 2.56, 95% CI 2.12 to 3.10). Targeted HIV interventions among MSM need to promote and distribute latex condom-compatible lubricants for use during anal sex—irrespective of their presumed or stated sexual role in anal sex, and educate them not to use oil-based lubricants with condoms

Estimated impact of exposure to community groups on STI-related outcomes among female sex workers.

<p>^# Treated (exposed to community group membership)</p><p>^$ Untreated (Unexposed to community group membership)</p><p>ATT- Average treatment effect among treated</p><p>ATU- Average treatment effect among untreated</p><p>ATE- Average treatment effect</p