Gaussian Fluctuation in Random Matrices

Let $N(L)$ be the number of eigenvalues, in an interval of length $L$, of a matrix chosen at random from the Gaussian Orthogonal, Unitary or Symplectic ensembles of ${\cal N}$ by ${\cal N}$ matrices, in the limit ${\cal N}\rightarrow\infty$. We prove that $[N(L) - \langle N(L)\rangle]/\sqrt{\log L}$ has a Gaussian distribution when $L\rightarrow\infty$. This theorem, which requires control of all the higher moments of the distribution, elucidates numerical and exact results on chaotic quantum systems and on the statistics of zeros of the Riemann zeta function. \noindent PACS nos. 05.45.+b, 03.65.-wComment: 13 page

Spatial Current Patterns, Dephasing and Current Imaging in Graphene Nanoribbons

Using the non-equilibrium Keldysh Green's function formalism, we investigate the local, non-equilibrium charge transport in graphene nanoribbons (GNRs). In particular, we demonstrate that the spatial current patterns associated with discrete transmission resonances sensitively depend on the GNRs' geometry, size, and aspect ratio, the location and number of leads, and the presence of dephasing. We identify a relation between the spatial form of the current patterns, and the number of degenerate energy states participating in the charge transport. Furthermore, we demonstrate a principle of superposition for the conductance and spatial current patterns in multiple-lead configurations. We demonstrate that scanning tunneling microscopy (STM) can be employed to image spatial current paths in GNR with atomic resolution, providing important insight into the form of local charge transport. Finally, we investigate the effects of dephasing on the spatial current patterns, and show that with decreasing dephasing time, the current patterns evolve smoothly from those of a ballistic quantum network to those of classical resistor network.Comment: 25 pages, 12 figure

Application of Modified Shell Vial Culture Procedure for Arbovirus Detection

The isolation of arboviruses from patient's low titer sera can be difficult. Here we compared the detection efficiency of Dengue (DEN), Yellow Fever (YF), Saint Louis Encephalitis (SLE), West Nile (WN), Ilheus (ILH), Group C (GC), Oropouche (ORO), Mayaro (MAY) and Venezuela Encephalitis Equine (VEE) viruses using a Modified Shell Vial Culture (MSVC) protocol to a Standard Cell Culture (SCC) protocol. First the MSVC and SCC protocols were compared using five dilutions for each of the following stock viruses: DEN-1, DEN-2, DEN-3, DEN-4, YF, SLE, WN, ILH, GC, ORO, MAY and VEE. Next, patients' original sera from which viruses (DEN-1, DEN-2, DEN-3, YF, GC, ORO, MAY and VEE) had been previously isolated were compare by the two methods using five sera dilutions. In addition, seven sera that were positive for DEN-3 by RT-PCR and negative by SCC were processed by MSVC. The MSVC protocol was consistently 1-2 logs higher virus dilution more sensitive for virus detection than the SCC protocol for all stock Flaviviruses tested (DEN-1, DEN-2, DEN-3, DEN-4, YF, SLE, WN and ILH). MSVC was equal to or one log more sensitive for virus detection than SCC for the stock Bunyaviruses (GC and ORO). For the stock Alphavirus MAY, MSVC was equally or one log more sensitive for virus detection than SCC, while for VEE SCC was equally or one log more sensitive for virus detection than MSVC. MSVC was consistently one to two sera dilutions more sensitive than SCC for the detection of Flaviviruses from patients' sera. Both methods were approximately equally sensitive for the detection of Bunyaviruses from patients' sera and equal or one dilution less sensitive for the detection of Alphaviruses from patients' sera. Additionally, MSVC detected DEN virus in five of seven DEN-3 RT-PCR positive, SCC negative patients' sera

Are ulcers a marker for invasive carcinoma in barrett's esophagus? data from a diagnostic variability study with clinical follow-up

We correlated follow-up information from 138 patients with Barrett's esophagus and varying degrees of dysplasia with the presence of ulcers. Methods A group of pathologist participants were asked to contribute patients’ initial biopsy slides showing Barrett's esophagus (BE) without dysplasia and with epithelial changes indefinite for dysplasia, low grade dysplasia (LGD), high grade dysplasia (HGD), and adenocarcinoma. From the initial 250 cases used for a diagnostic reproducibility study, follow-up information was available for 138 patients. Results There were 44 cases submitted as BE, 22 as BE with epithelial changes indefinite for dysplasia, 26 as BE with LGD, 33 as BE with HGD, and 13 as BE with adenocarcinoma. Ulcers were present in 35/138 cases (25%), including 3/44 cases of BE without dysplasia (7%), 2/22 cases of BE with epithelial changes indefinite for dysplasia (9%), 0/26 cases of BE with LGD (0%), 10/33 cases of BE with HGD (30%), and 7/13 cases of BE with adenocarcinoma (54%). On follow-up, there were no invasive carcinomas detected among the BE without dysplasia group (median follow-up = 38.5 months). Adenocarcinomas were detected in 4/22 cases (18%) submitted as BE with epithelial changes indefinite for dysplasia at 19, 55, 60, and 62 months and in 4/26 cases (15%) of BE with LGD at 9, 9, 11, and 60 months. None of these carcinomas occurred in cases in which an ulcer was present in the initial biopsy specimen. Among the 33 HGD cases, 20 (60%) were found to have adenocarcinoma on subsequent resection specimens. The presence of an ulcer with HGD increased the likelihood of finding carcinoma in the resection specimen, as 8/10 biopsies (80%) of HGD patients with ulcers had carcinoma, compared to 12/23 biopsies (52%) of HGD patients without ulcers. All of the cases interpreted as adenocarcinomas on biopsy were found either to have invasive carcinoma on esophageal resection or to have metastases that were demonstrated in unresectable patients. Conclusion If an ulcer accompanies HGD in a biopsy specimen from a patient with BE, it is likely that invasive carcinoma is also present at that time.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75186/1/j.1572-0241.2002.05420.x.pd

Web Queries as a Source for Syndromic Surveillance

In the field of syndromic surveillance, various sources are exploited for outbreak detection, monitoring and prediction. This paper describes a study on queries submitted to a medical web site, with influenza as a case study. The hypothesis of the work was that queries on influenza and influenza-like illness would provide a basis for the estimation of the timing of the peak and the intensity of the yearly influenza outbreaks that would be as good as the existing laboratory and sentinel surveillance. We calculated the occurrence of various queries related to influenza from search logs submitted to a Swedish medical web site for two influenza seasons. These figures were subsequently used to generate two models, one to estimate the number of laboratory verified influenza cases and one to estimate the proportion of patients with influenza-like illness reported by selected General Practitioners in Sweden. We applied an approach designed for highly correlated data, partial least squares regression. In our work, we found that certain web queries on influenza follow the same pattern as that obtained by the two other surveillance systems for influenza epidemics, and that they have equal power for the estimation of the influenza burden in society. Web queries give a unique access to ill individuals who are not (yet) seeking care. This paper shows the potential of web queries as an accurate, cheap and labour extensive source for syndromic surveillance

Concurrent Outbreak of Norovirus Genotype I and Enterotoxigenic Escherichia coli on a U.S. Navy Ship following a Visit to Lima, Peru

An outbreak of norovirus (NoV) genotype I and Enterotoxigenic Escherichia coli (ETEC) occurred among US Navy Ship personnel following a visit to Lima, Peru, in June 2008. Visiting a specific area in Lima was significantly associated with illness. While ETEC and NoV are commonly recognized as causative agents of outbreaks, co-circulation of both pathogens has been rarely observed in shipboard outbreaks

A growing global network’s role in outbreak response: AFHSC-GEIS 2008-2009

A cornerstone of effective disease surveillance programs comprises the early identification of infectious threats and the subsequent rapid response to prevent further spread. Effectively identifying, tracking and responding to these threats is often difficult and requires international cooperation due to the rapidity with which diseases cross national borders and spread throughout the global community as a result of travel and migration by humans and animals. From Oct.1, 2008 to Sept. 30, 2009, the United States Department of Defense’s (DoD) Armed Forces Health Surveillance Center Global Emerging Infections Surveillance and Response System (AFHSC-GEIS) identified 76 outbreaks in 53 countries. Emerging infectious disease outbreaks were identified by the global network and included a wide spectrum of support activities in collaboration with host country partners, several of which were in direct support of the World Health Organization’s (WHO) International Health Regulations (IHR) (2005). The network also supported military forces around the world affected by the novel influenza A/H1N1 pandemic of 2009. With IHR (2005) as the guiding framework for action, the AFHSC-GEIS network of international partners and overseas research laboratories continues to develop into a far-reaching system for identifying, analyzing and responding to emerging disease threats

Immunopotentiation of Trivalent Influenza Vaccine When Given with VAX102, a Recombinant Influenza M2e Vaccine Fused to the TLR5 Ligand Flagellin

BACKGROUND: Currently controversy exists about the immunogenicity of seasonal trivalent influenza vaccine in certain populations, especially the elderly. STF2.4×M2e (VAX102) is a recombinant fusion protein that links four copies of the ectodomain of influenza virus matrix protein 2 (M2e) antigen to Salmonella typhimurium flagellin, a TLR5 ligand. The objectives of this study were to assess the feasibility of giving VAX102 and TIV in combination in an effort to achieve greater immunogenicity and to provide cross-protection. METHODOLOGY/PRINCIPAL FINDINGS: Eighty healthy subjects, 18-49 years old, were enrolled in May and June 2009 in a double-blind, randomized, controlled trial at two clinical sites. Subjects were randomized to receive either TIV + VAX102 or TIV + placebo. Both arms tolerated the vaccines. Pain at the injection site was more severe with TIV + VAX102. Two weeks after immunization the HAI responses to the H1 and H3 antigens of TIV were higher in those that received TIV + VAX102 than in TIV + placebo (309 vs 200 and 269 vs 185, respectively), although statistically non-significant. There was no difference in the HAI of the B antigen. In the TIV + VAX102 arm, the geometric mean M2e antibody concentration was 0.5 µg/ml and 73% seroconverted. CONCLUSIONS/SIGNIFICANCE: The combination of TIV + VAX102 has the potential to increase the immune response to the influenza A components of TIV and to provide M2e immunity which may protect against influenza A strains not contained in seasonal TIV. TRIAL REGISTRATION: ClinicalTrials.gov NCT00921973

Microbiome sharing between children, livestock and household surfaces in western Kenya

The gut microbiome community structure and development are associated with several health outcomes in young children. To determine the household influences of gut microbiome structure, we assessed microbial sharing within households in western Kenya by sequencing 16S rRNA libraries of fecal samples from children and cattle, cloacal swabs from chickens, and swabs of household surfaces. Among the 156 households studied, children within the same household significantly shared their gut microbiome with each other, although we did not find significant sharing of gut microbiome across host species or household surfaces. Higher gut microbiome diversity among children was associated with lower wealth status and involvement in livestock feeding chores. Although more research is necessary to identify further drivers of microbiota development, these results suggest that the household should be considered as a unit. Livestock activities, health and microbiome perturbations among an individual child may have implications for other children in the household