Cellular dynamic simulator: an event driven molecular simulation environment for cellular physiology.

In this paper, we present the Cellular Dynamic Simulator (CDS) for simulating diffusion and chemical reactions within crowded molecular environments. CDS is based on a novel event driven algorithm specifically designed for precise calculation of the timing of collisions, reactions and other events for each individual molecule in the environment. Generic mesh based compartments allow the creation / importation of very simple or detailed cellular structures that exist in a 3D environment. Multiple levels of compartments and static obstacles can be used to create a dense environment to mimic cellular boundaries and the intracellular space. The CDS algorithm takes into account volume exclusion and molecular crowding that may impact signaling cascades in small sub-cellular compartments such as dendritic spines. With the CDS, we can simulate simple enzyme reactions; aggregation, channel transport, as well as highly complicated chemical reaction networks of both freely diffusing and membrane bound multi-protein complexes. Components of the CDS are generally defined such that the simulator can be applied to a wide range of environments in terms of scale and level of detail. Through an initialization GUI, a simple simulation environment can be created and populated within minutes yet is powerful enough to design complex 3D cellular architecture. The initialization tool allows visual confirmation of the environment construction prior to execution by the simulator. This paper describes the CDS algorithm, design implementation, and provides an overview of the types of features available and the utility of those features are highlighted in demonstrations.

Patient satisfaction and nursing staff work satisfaction in an urban public teaching hospital

This study examined the level of patient satisfaction and nursing staff work satisfaction at an urban public hospital in the Southwestern United States. The primary objectives of this study were to determine: (1) the level of overall patient satisfaction and satisfaction with specific dimensions of hospital care; (2) the differences in patient satisfaction according to demographic characteristics (age, gender, ethnicity, and education completed) and predispositional factors (perceived health status, perceived level of pain, prior contact with the hospital, and hospital image) and the relative importance of each variable on patient satisfaction; (3) the level of overall work satisfaction and satisfaction with specific dimensions of work experienced by the medical/surgical nursing staff; (4) the differences in work satisfaction experienced by the nursing staff based on demographic variables (age, gender, ethnicity, and marital status) and professional factors (education completed, staff position, the number of years employed with the hospital, and number of years employed in nursing) and the relative importance of each variable on work satisfaction; and (5) to determine the effect of the nursing work milieu on patient and staff satisfaction.^ The study findings showed that patients experienced a moderate to low level of satisfaction with the dimensions of hospital care (admission process, daily care, information, nursing care, physician care, other hospital staff, living arrangements, and overall care). Of the eight dimensions of care, patients reported a relatively positive level of satisfaction (75 percent or better) with only one dimension: physician care. Ethnicity, perceived health status, and hospital image were significantly related to patient satisfaction. Hispanic patients, those who were in good health, and those who felt the hospital had a good image in their community were most satisfied with hospital care. Patients also reported areas of hospital care that needed the most improvement. Responses included: rude staff, better nursing care, and better communication.^ Findings from the nursing satisfaction survey indicated a low level of satisfaction with the dimensions of work (autonomy, pay, professional status, interaction, task requirements, and organizational policies). Only one dimension of work, professional status, received a mean satisfaction score in the positive range. Additionally, staff members were unanimously dissatisfied with their salaries. Frequently mentioned work-related problems reported by the staff included: staffing shortages, heavy patient loads. and excessive paperwork.^ The nursing milieu appeared to have had a significant effect on the satisfaction levels of patients nursing staff employees. The nursing staff were often short staffed, which increased the patient-to-nurse ratio. Consequently, patients did not receive the amount of attention and care they expected from the nursing staff. Crowded patient rooms allowed for little personal space and privacy. Dissatisfaction with living conditions served to influence patients' attitudes and satisfaction levels. These frustrations were often directed toward their primary caregivers, the nursing staff. Consequently, the nursing milieu appeared to directly affect and influence the satisfaction levels of both patients and staff. (Abstract shortened by UMI). ^

Emergency health care assessment in the Houston-Galveston region 2002--2006

Background. Previous studies show emergency rooms to be over crowded nation wide. With growing attention to this problem, the Houston-Galveston Area Council (H-GAC) initiated a study in 2005 to assess their region's emergency health care system, and continued this effort in 2007. The purpose of this study was to examine recent changes in volume, capacity and performance in the Houston-Galveston region's emergency health care system and determine whether the system has been able to effectively respond to the residents' demands. Methods. Data were collected by the Houston-Galveston Area Council and The Abaris Group using a self-administered 2002-2006 survey completed by administrators of the region's hospitals, EMS providers, and select fire departments that provide EMS services. Data from both studies were combined and matched to examine trends. Results. Volume increased among the reporting hospitals within the Houston-Galveston region from 2002 to 2006; however, capacity remained relatively unchanged. EMS providers reported higher average off load times in 2007 compared to 2005, but the increases were not statistically significant. Hospitals reported transferring a statistically significant greater percentage of patients in 2006 than 2004. There was no statistically significant change in any of the other measures. Conclusion. These findings indicate an increase in demand for the Houston-Galveston region's emergency healthcare services with no change in supply. Additional studies within the area are needed to fully assess and evaluate the impact of these changes on system performance. ^

An analysis of the RightCare policy at Ben Taub General Hospital, Houston, Texas

Introduction. This study is a two-part evaluation of the RightCare policy, a policy implemented to reduce crowding at the Emergency Center (EC) at Ben Taub General Hospital in Houston, Harris County, Texas. This research includes an evaluation of the policy's impact on specific hospital measures, along with a description of the policy's demise from the point of view of hospital staff. Objective. The purpose of this study is two-fold: (1) To determine whether RightCare policy affected the level of crowding in the Emergency Center and (2) to identify the conditions that may have led to the policy's demise. Methods. For the policy impact portion of this research, hospital measures were collected from existing databases. Analysis included a pre-post comparative design in which the 12 months preceding the policy's implementation were compared with the 12 months following the policy's implementation. For the policy perception portion, employees were surveyed using an on-line questionnaire. Results. The results of the study are mixed. Some measures improved, including time spent on ambulance diversion and the proportion of those who left without being seen, while others did not, such as return visits and total length of stay. Employees generally supported the policy, but expressed concerns over insufficient training and funding. Conclusion. The RightCare policy was a good initial attempt to improve crowded conditions in the EC. The study showed that a clearer policy design, improved training, adequate staffing levels, and better communication would improve operational outcomes in the future.^

THE MEASUREMENT OF HUMANISTIC AND DEHUMANISTIC BEHAVIORS IN HOSPITAL NURSING ENVIRONMENTS

The purpose of this investigation was to develop a reliable scale to measure the social environment of hospital nursing units according to the degree of humanistic and dehumanistic behaviors as perceived by nursing staff in hospitals. The study was based on a conceptual model proposed by Jan Howard, a sociologist. After reviewing the literature relevant to personalization of care, analyzing interviews with patients in various settings, and studying biological, psychological, and sociological frames of reference, Howard proposed the following necessary conditions for humanized health care. They were the dimensions of Irreplaceability, Holistic Selves, Freedom of Action, Status Equality, Shared Decision Making and Responsibility, Empathy, and Positive Affect.^ It was proposed that a scale composed of behaviors which reflected Howard's dimensions be developed within the framework of the social environment of nursing care units in hospitals. Nursing units were chosen because hospitals are traditionally organized around nursing care units and because patients spend the majority of their time in hospitals interacting with various levels of nursing personnel.^ Approximately 180 behaviors describing both patient and nursing staff behaviors which occur on nursing units were developed. Behaviors which were believed to be humanistic as well as dehumanistic were included. The items were classified under the dimensions of Howard's model by a purposively selected sample of 42 nurses representing a broad range of education, experience, and clinical areas. Those items with a high degree of agreement, at least 50%, were placed in the questionnaire. The questionnaire consisted of 169 items including six items from the Marlowe Crowne Social Desirability Scale (Short Form).^ The questionnaire, the Social Environment Scale, was distributed to the entire 7 to 3 shift nursing staff (603) of four hospitals including a public county specialty hospital, a public county general and acute hospital, a large university affiliated hospital with all services, and a small general community hospital. Staff were asked to report on a Likert type scale how often the listed behaviors occurred on their units. Three hundred and sixteen respondents (52% of the population) participated in the study.^ An item analysis was done in which each item was examined in relationship to its correlation to its own dimension total and to the totals of the other dimensions. As a result of this analysis, three dimensions, Positive Affect, Irreplaceability, and Freedom of Action were deleted from the scale. The final scale consisted of 70 items with 26 in Shared Decision Making and Responsibility, 25 in Holistic Selves, 12 in Status Equality, and seven in Empathy. The alpha coefficient was over .800 for all scales except Empathy which was .597.^ An analysis of variance by hospital was performed on the means of each dimension of the scale. There was a statistically significant difference between hospitals with a trend for the public hospitals to score lower on the scale than the university or community hospitals. That the scale scores should be lower in crowded, understaffed public hospitals was not unexpected and reflected that the scale had some discriminating ability. These differences were still observed after adjusting for the effect of Social Desirability.^ In summary, there is preliminary evidence based on this exploratory investigation that a reliable scale based on at least four dimensions from Howard's model could be developed to measure the concept of humanistic health care in hospital settings. ^