Effect of Ion Concentration Changes in the Limited Extracellular Spaces on Sarcolemmal Ion Transport and Ca2+ Turnover in a Model of Human Ventricular Cardiomyocyte

We have developed a computer model of human cardiac ventricular myocyte (CVM), including t-tubular and cleft spaces with the aim of evaluating the impact of accumulation-depletion of ions in restricted extracellular spaces on transmembrane ion transport and ionic homeostasis in human CVM. The model was based on available data from human CVMs. Under steady state, the effect of ion concentration changes in extracellular spaces on [Ca²⁺]_i-transient was explored as a function of critical fractions of ion transporters in t-tubular membrane (not documented for human CVM). Depletion of Ca²⁺ and accumulation of K⁺ occurring in extracellular spaces slightly affected the transmembrane Ca²⁺ flux, but not the action potential duration (APD₉₀). The [Ca²⁺]_i-transient was reduced (by 2%–9%), depending on the stimulation frequency, the rate of ion exchange between t-tubules and clefts and fractions of ion-transfer proteins in the t-tubular membrane. Under non-steady state, the responses of the model to changes of stimulation frequency were analyzed. A sudden increase of frequency (1–2.5 Hz) caused a temporal decrease of [Ca²⁺] in both extracellular spaces, a reduction of [Ca²⁺]_i-transient (by 15%) and APD₉₀ (by 13 ms). The results reveal different effects of activity-related ion concentration changes in human cardiac t-tubules (steady-state effects) and intercellular clefts (transient effects) in the modulation of membrane ion transport and Ca²⁺ turnover.     

Expanding a performance improvement initiative in critical care from hospital to system

BACKGROUND: Concern about the expense and effects of intensive care prompted the development and implementation of a hospital-based performance improvement initiative in critical care at North Shore University Hospital, Manhasset, New York, a 730-bed acute care teaching hospital. THE HOSPITAL-BASED PERFORMANCE IMPROVEMENT INITIATIVE IN CRITICAL CARE: The initiative was intended to use a uniform set of measurements and guidelines to improve patient care and resource utilization in the intensive care units (ICUs), to establish and implement best practices (regarding admission and discharge criteria, nursing competency, unplanned extubations, and end-of-life care), and to improve performance in the other hospitals in the North Shore-Long Island Jewish Health System. In the medical ICU, the percentage of low-risk (low-acuity) patients was reduced from 42% to 22%. ICU length of stay was reduced from 4.6 days to 4.1 days. IMPLEMENTING THE CRITICAL CARE PROJECT SYSTEMWIDE: A system-level critical care committee was convened in 1996 and charged with replicating the initiative. By and large, system efforts to integrate and implement policies have been successful. The critical care initiative has provided important comparative data and information from which to gauge individual hospital performance. DISCUSSION: Changing the critical care delivered on multiple units at multiple hospitals required sensitivity to existing organizational cultures and leadership styles. Merging organizational cultures is most successful when senior leadership set clear expectations that support the need for change. The process of collecting, trending, and communicating quality data has been instrumental in improving care practices and fostering a culture of safety throughout the health care system.     

Cognitive versus behavior therapy in the group treatment of Obsessive-Compulsive disorder.

This study examined the effects of cognitive-behavior therapy (CBT) compared with traditional behavior therapy (exposure and response prevention [ERP]) in the group treatment of obsessive-compulsive disorder. Of the 76 participants who started treatment, 38 were wait-listed for 3 months before treatment to assess possible course effects. Both treatments were superior to the control condition in symptom reduction, with ERP being marginally more effective than CBT by end of treatment and again at 3-month follow-up. In terms of clinically significant improvement, treatment groups were equivalent on the conclusion of treatment, but 3 months later significantly more ERP participants met criteria for recovered status. Only 1 of 7 belief measures changed with treatment improvement, and the extent of this cognitive change was similar between CBT and ERP groups. Discussion includes consideration of optimal formats for the delivery of different types of treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Symptoms of depression and survival experience among three samples of smokers trying to quit.

Symptoms of depression have been associated with increased smoking prevalence and failure to quit smoking in several cross-sectional and population-based studies. Few studies, however, have prospectively examined the ability of current symptoms of depression to predict failure to quit smoking in treatment-motivated smokers. Pretreatment depressed mood was assessed by 3 different methods in 3 separate samples, 2 of which comprised smokers receiving combined pharmacological and behavioral treatments and a 3rd in which smokers received self-help materials only. In all studies, time in days from quit day until the 1st cigarette was ascertained to document survival. Survival analyses showed that in all 3 studies survival time was significantly and negatively related to measures of even very low levels of pretreatment depressed mood. Results were replicated across 3 independent samples and were robust and uniformly clear, indicating that low levels of depressive symptoms assessed at baseline predict time to 1st cigarette smoked after attempted quitting. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hybridisation of LEDs with silicon microsensors

This paper presents the experiments we performed for hybrid integration of LEDs with silicon optical readout microsensors. LEDs were face down mounted, in a silicon cavity, on the same wafer with the sensor. The edge-emitted light is coupled into SiON waveguides. The LEDs hybridization steps were included in the technological processes of two types of silicon microsensors: chemo-optical and mechano-optical sensors. The proper technological steps succession was established according to the limitation imposed by lithography on wafers with deep groves and the thermal behavior of transducing layers. The main problem we solved was the matching of all the involved processes: integrated optics, micromachining, thin-film technology, CMOS technology.     

Making time count: Functional evidence for temporal coding of taste sensation.

Although the temporal characteristics of neural responses have been proposed as a mechanism for sensory neural coding, there has been little evidence thus far that this type of information is actually used by the nervous system. Here the authors show that patterned electrical pulses trains that mimic the response to the taste of quinine can produce a bitterlike sensation when delivered to the nucleus tractus solitarius of behaving rats. Following conditioned aversion training using either "quinine simulation" patterns of electrical stimulation or natural quinine (0.1 mM) as a conditioned stimulus, rats specifically generalized the aversion to 2 bitter tastants: quinine and urea. Randomization of the quinine simulation patterns resulted in generalization patterns that resembled those to a perithreshold concentration (0.01 mM) of quinine. These data provide strong evidence that the temporal pattern of brainstem activity may convey information about taste quality and underscore the functional significance of temporal coding. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Children's residential exposure to chlorpyrifos: application of CPPAES field measurements of chlorpyrifos and TCPy within MENTOR/SHEDS-Pesticides model

The comprehensive individual field-measurements on non-dietary exposure collected in the Children's-Post-Pesticide-Application-Exposure-Study (CPPAES) were used within MENTOR/SHEDS-Pesticides, a physically based stochastic human exposure and dose model. In this application, however, the model was run deterministically. The MENTOR/SHEDS-Pesticides employed the CPPAES as input variables to simulate the exposure and the dose profiles for seven children over a 2-week post-application period following a routine residential and professional indoor crack-and-crevice chlorpyrifos application. The input variables were obtained from a personal activity diary, microenvironmental measurements and personal biomonitoring data obtained from CPPAES samples collected from the individual children and in their homes. Simulation results were compared with CPPAES field measured values obtained from the children's homes to assess the utility of the different microenvironmental data collected in CPPAES, i.e. indicator toys and wipe samplers to estimate aggregate exposures that can be result from one or more exposure pathways and routes. The final analyses of the database involved comparisons of the actual data obtained from the individual biomarker samples of a urinary metabolite of chlorpyrifos (TCPy) and the values predicted by MENTOR/SHEDS-Pesticides using the CPPAES-derived variables. Because duplicate diet samples were not part of the CPPAES study design, SHEDs-Pesticides simulated dose profiles did not account for the dietary route. The research provided more confidence in the types of data that can be used in the inhalation and dermal contact modules of MENTOR/SHEDS-Pesticides to predict the pesticide dose received by a child. It was determined that we still need additional understanding about: (1) the types of activities and durations of activities that result in non-dietary ingestion of pesticides and (2) the influence of dietary exposures on the levels of TCPy found in the urine.     

A generative model of article citation networks of a subject from a large-scale citation database

Scientometrics - In this paper, we analyze the structure of the article citation network of a particular subject obtained from the Web of Science (WoS) database. In specific, we modify a model...     

A Missing Link in Suggestibility Research: What Is Known About the Behavior of Field Interviewers in Unstructured Interviews With Young Children?

Despite suggestibility researchers' focus on adult behaviors that distort children's reports, whether behaviors examined in experimental work are used in the field is unknown. The current study presents a mutually exclusive and exhaustive hierarchical coding system that reflects interview questioning behaviors of concern in experimental work. The study examined 80 unstructured interviews conducted by 41 field interviewers with 40 children ages 3 to 7 about known events. Data on the use of leading and neutral questions are presented and include distinctions between accurate and inaccurate suggested information. In addition, analyses show that interviewers are consistent in their style of questioning and that a preinterview measure of interviewers' preference for a qualitative versus a quantitative interviewing style predicted the introduction of novel information into the interview. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Group structuring techniques and their influence on process involvement in a group counseling training group.

Investigated the role of a group structuring technique developed by G. Egan (1973, 1976) on the amount and depth of process involvement in 2 8-member counseling training groups consisting of graduate students (aged 21–56 yrs). The primary hypothesis was that the structured group would have a higher amount and depth of process involvement scores across time than the no-structure group. Results partly support the conclusion that early structure significantly affects process involvement among group members. Findings also indicate that both groups showed strong gains in depth of process involvement over time. Results are discussed in terms of previous research by R. L. Bednar et al (see record 1974-25973-001) and C. Y. Crews and J. Melnick (see record 1976-21029-001). It is suggested that future research should explore interactions between interpersonal style differences of individual members and various structuring techniques. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)