Equivalence of a one-dimensional driven-diffusive system and an equilibrium two-dimensional walk model

It is known that a single product shock measure in some of one-dimensional driven-diffusive systems with nearest-neighbor interactions might evolve in time quite similar to a random walker moving on a one-dimensional lattice with reflecting boundaries. The non-equilibrium steady-state of the system in this case can be written in terms of a linear superposition of such uncorrelated shocks. Equivalently, one can write the steady-state of this system using a matrix-product approach with two-dimensional matrices. In this paper we introduce an equilibrium two-dimensional one-transit walk model and find its partition function using a transfer matrix method. We will show that there is a direct connection between the partition functions of these two systems. We will explicitly show that in the steady-state the transfer matrix of the one-transit walk model is related to the matrix representation of the algebra of the driven-diffusive model through a similarity transformation. The physical quantities are also related through the same transformation.Comment: 5 pages, 2 figures, Revte

Measurement and Predictors of Resilience Among Community-Dwelling Elderly in Kashan, Iran: A Cross-Sectional Study

Background: As the ability to cope with challenging conditions, resilience results in personal growth and development after experiencing tragic conditions. There are limited studies regarding resilience and its associated factors in elderly patients in Iran. Given that the cultural, social, religious characteristics might affect the level of resilience, we conducted the present study among an elderly population in Kashan. Objectives: This study aimed to evaluate the resilience and its associated factors among elderly in Kashan City, Iran. Methods: A cross-sectional study was conducted on 500 individuals who were selected through a two-stage randomized cluster sampling methods among elderly residents of 8 urban health care facilities in Kashan, Iran. Data collection was performed using a five-part instrument including a demographics questionnaire and abbreviated mental test scale, the Connor-Davidson resilience scale, Rosenberg self-esteem scale, and general health questionnaire28. Data were analyzed using descriptive statistics, chi-square test, t-test, analysis of variance and multivariate regression analysis. Results: A significant direct association was found between resilience and the self-esteem scores (r = 0.461, P < 0.001). Conversely, an indirect correlation was found between resilience and mental health scores (r = - 0.510, P < 0.001). Regression analysis showed that self-esteem and mental health could explain 32% of the variance of resilience in older adults. Significant relationships were found between resilience and variables such as age, sex, marital status, income, job, education, and life arrangement (P < 0.05). Conclusions: Several factors including personal characteristics, self-esteem and mental health of the elderly can affect their resilience. Choosing some strategies to modify and improve some of the influencing variables may be effective in increasing the resilience in older adults

Genetic profile variation in vaccine strains and clinical isolates of bordetella pertussis recovered from iranian patients

Background: Re-emergence of pertussis has been reported in Iran despite a high rate of vaccination coverage. Low efficacy of the vaccine might be due to the genetic divergence between clinical versus vaccine strains. In the current study, the genetic profiles of clinical isolates and vaccine strains of Bordetella pertussis (B. pertussis) were assessed by using Pulsed Field Gel Electrophoresis (PFGE). Methods: Following phenotypic and molecular identification of isolates, XbaIdigested genomic DNA of 5 clinical isolates, 2 vaccine strains and a Tohama I strain were analyzed by PFGE along with B. parapertussis as a control. Results: Seven distinct PFGE profiles were found among all examined isolates/ strains. In 5 clinical isolates, 4 profiles were identified whereas the vaccine strains displayed 2 distinct profiles. The reference strain, Tohama I had a distinct profile. Vaccine and clinical profiles had low similarity, with relatedness of approximately 40. Conclusion: The genetic profiles of B. pertussis were different between circulating isolates and vaccine strains used in the national vaccination programs. Since new genetic profiles of B. pertussis can be disseminated periodically, the profiles of isolates circulating in the population should be monitored over the course of the re-emergence. © 2014, Avicenna Journal of Medical Biotechnology. All rights reserved

Carbapenem-resistant Acinetobacter baumannii recovered from burn patients

Purpose. Emergence of carbapenem-resistant Acinetobacter baumannii (CRAB) and their prolonged presence in burn units increases the risk of acquisition of CRAB. Methods. From November 2012 to September 2013, 1474 burn patients were screened for CRAB isolates through testing susceptibility to imipenem and its comparators meropenem, and doripenem. Furthermore, the in vitro activity of other antibiotics against CRAB was investigated. Results. Three patients were infected with carbapenem-susceptible A. baumannii (CSAB) and 168 were infected with CRAB. Approximately one-fifth (n=32) of CRAB isolates were obtained from patients hospitalized in Burn Intensive Care Unit (BICU). Most of CRABs were isolated from wound. The mean length of stay (LOS) in hospital prior to A. baumannii isolation was significantly higher for CRAB compared to CSAB cases (P=0.04). Amongst the independent variables, percentage of total burn surface area (TBSA) significantly increased the mortality rate using multivariate logistic regression (P=0.001, OR= 16.5; 95 CI: 4.72-57.7). The majority of tested isolates were resistant to imipenem (94.8), and to its comparators, doripenem (97.7), and meropenem (97.7). The susceptibility of CRAB isolates was less than 10 to all tested antibiotics except for colistin (100), doxycycline (61.9), gentamicin (18.5), and tigecycline (11.9). Conclusion. Resistance to carbapenem reduces the number of effective antibiotics. The coordinated and intensive efforts of healthcare personnel are required to meet the challenge of dissemination of CRA

ATP signalling in epilepsy

This paper focuses on a role for ATP neurotransmission and gliotransmission in the pathophysiology of epileptic seizures. ATP along with gap junctions propagates the glial calcium wave, which is an extraneuronal signalling pathway in the central nervous system. Recently astrocyte intercellular calcium waves have been shown to underlie seizures, and conventional antiepileptic drugs have been shown to attenuate these calcium waves. Blocking ATP-mediated gliotransmission, therefore, represents a potential target for antiepileptic drugs. Furthermore, while knowledge of an antiepileptic role for adenosine is not new, a recent study showed that adenosine accumulates from the hydrolysis of accumulated ATP released by astrocytes and is believed to inhibit distant synapses by acting on adenosine receptors. Such a mechanism is consistent with a surround-inhibitory mechanism whose failure would predispose to seizures. Other potential roles for ATP signalling in the initiation and spread of epileptiform discharges may involve synaptic plasticity and coordination of synaptic networks. We conclude by making speculations about future developments

Interactions between metal ions and DNA

84 years elapsed between the announcements of the periodic table and that of the DNA double helix in 1953, and the two have been combined in many ways since then. In this chapter an outline of the fundamentals of DNA structure leads into a range of examples showing how the natural magnesium and potassium ions found in nature can be substituted in a diversity of applications. The dynamic structures found in nature have been studied in the more controlled but artificial environment of the DNA crystal using examples from sodium to platinum and also in a range of DNA-binding metal complexes. While NMR is an essential technique for studying nucleic acid structure and conformation, most of our knowledge of metal ion binding has come from X-ray crystallography. These days the structures studied, and therefore also the diversity of metal binding, go beyond the double helix to triplexes, hairpin loops, junctions and quadruplexes, and the chapter describes briefly how these pieces fit into the DNA jigsaw. In a final section, the roles of metal cations in the crystallisation of new DNA structures are discussed, along with an introduction to the versatility of the periodic table of absorption edges for nucleic acid structure determination

EVALUATION OF THE METERED-DOSE INHALER TECHNIQUE AMONG HEALTHCARE PROVIDERS

Poor inhaler technique is a common problem both in asthmatic patients and healthcare providers, which contributes to poor asthma control. This study was performed to evaluate the adequacy of metered-dose inhaler (MDI) technique in a sample of physicians and nurses practicing in hospitals of Hamadan University of Medical Sciences. A total of 173 healthcare providers voluntary participated in this study. After the participants answered a questionnaire aimed at identifying their involvement in MDI prescribing and counseling, a trained observer assessed their MDI technique using a checklist of nine steps. Of the 173 participants, 35 (20.2%) were physicians and 138 (79.8%) were nurses. Only 12 participants (6.93%) performed all steps correctly. Physicians performed essential steps significantly better than nurses (85.7% vs. 63.8%, P &lt; 0.05). The majority of healthcare providers responsible for instructing patients on the correct MDI technique were unable to perform this technique correctly, indicating the need for regular formal training programs on inhaler techniques