Intermediate-Level Crossings of a First-Passage Path

We investigate some simple and surprising properties of a one-dimensional Brownian trajectory with diffusion coefficient $D$ that starts at the origin and reaches $X$ either: (i) at time $T$ or (ii) for the first time at time $T$. We determine the most likely location of the first-passage trajectory from $(0,0)$ to $(X,T)$ and its distribution at any intermediate time $t<T$. A first-passage path typically starts out by being repelled from its final location when $X^2/DT\ll 1$. We also determine the distribution of times when the trajectory first crosses and last crosses an arbitrary intermediate position $x<X$. The distribution of first-crossing times may be unimodal or bimodal, depending on whether $X^2/DT\ll 1$ or $X^2/DT\gg 1$. The form of the first-crossing probability in the bimodal regime is qualitatively similar to, but more singular than, the well-known arcsine law.Comment: 18 pages, 12 figures, IOP format; V2: various minor changes in response to referee comments. For publication in JSTA

DPOAE in HIV infected adults

HIV infection is associated with impairment of hearing function, at any stage of disease causing complication to the external, middle, inner ear and CNS. Audiological manifestation of HIV is a direct consequence of virus or secondary to the pharmacological treatment or viral complication. \ud Objectives: There is paucity of information pertaining to hearing status in HIV. As the deafness can occur at any stage of HIV with varying degree and people with HIV live longer, there is need to address the hearing problems in these individuals. So this study aimed detecting the outer hair cell functioning by doing DPOAE in normal hearing HIV infected adults.\ud Method: The experimental group comprised of 12 HIV infected (24 ears) within 20 to 40 years. The age matched control group comprised of 15 subjects (30 ears). All the subjects had normal hearing sensitivity. Initially puretone audiometry and immittance was performed for the subject selection. Subsequently DPOAE procedure was done. \ud Results: The DPOAE was abnormal in 50% of the subjects.\ud Conclusion: It can be concluded that the cochlear involvement is a common observation in HIV infected individuals. DPOAE test can be used as a tool for early identification of cochlear pathology in HIV infected

Potential of Mobile Phones to Serve as a Reservoir in Spread of Nosocomial Pathogens

Objective: The use of cellular telephones by medical personnel and the associated nosocomial transmission of pathogens have not been thoroughly examined. The objective of this study was to determine the incidence of bacterial colonisation on mobile phones of Healthcare workers (HCWs) and its accompanying resistance to commonly used antimicrobials in a medical and dental hospital in India. Method: A total of 204 mobile phones of HCWs from medical and dental departments were screened. A sterile swab moistened with sterile saline was rotated over the external surface of the phone. Swabs were cultured on 5% sheep blood agar and MacConkey agar plates. Plates were incubated aerobically at 37°C for 24 hours. All isolates were tested for antimicrobial susceptibility. A questionnaire was used for data collection on mobile phone use in hospital. Result: 99% of the phones demonstrated evidence of bacterial contamination. 64.8% of medical samples showed growth of pathogenic micro-organisms and 37.9% showed growth of Multi drug resistant bacteria. 59.37% of dental samples showed growth of pathogenic micro-organisms and 43.75% showed growth of Multi drug resistant bacteria. Pathogens isolated included Methicillin-resistant Staphylococcus aureus, Methicillin-sensitive Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Acinetobacter, Enterococcus faecalis, and Pseudomonas aeruginosa. According to the questionnaire 40% admitted to using their phones between examination of patients. Only 6% used disinfectants to wipe their phones. Conclusion: This study reveals that mobile phones are commonly used by HCWs, even during patient contact and may serve as a potential vehicle for the spread of nosocomial pathogens