Temporary Exclusion Research Articles

Occlusion as a measure for visual workload: an overview of TNO occlusion research in car driving

A process-oriented approach by systematically studying driver performance, distraction, and workload is the way to go for assessing safety effects of new telematics applications in vehicles. These systems may strive for drivers’ attention and possibly lead to distraction from the primary task. Visual occlusion techniques appear to be an effective means of studying drivers’ visual information processing performance. Studies to illustrate this include identifying the minimum visual information drivers need for driving (asking for visual information) and the evaluation of driver support systems such as heading control and adaptive cruise control with respect to visual workload. In other applications the occlusion technique is used to exclude ‘visual array’ information from the optic flow field. The temporary exclusion of part of the visual field of view was applied in evaluating the effects of different types of driver's side rearview mirrors.

Rotation Schemes in Politics - An Experimental Examination

Rotation schemes in political organizations imply the temporary exclusion of some organization's members (outsiders) from decision-making. Consequently, only a fraction of members (insiders) has a direct influence in the decision-making process, whose results, however, concern and affect all members of the organization. Even though rotation schemes have been implemented in some political organizations - and are about to become more important in the European Union in the course of future enlargements - the political and economic consequences of rotation schemes, compared to an encompassing representation system, have not been thoroughly studied. We examine the effects of rotation schemes on the provision of a public good in groups. In particular, we study the degree of cooperation of (rotating) insiders and outsiders in an experiment and compare cooperation in rotation schemes with cooperation levels without rotation.

Role of healthcare workers in outbreaks of methicillin-resistant Staphylococcus aureus: a 10-year evaluation from a Dutch university hospital.

The benefit of screening healthcare workers (HCWs) at risk for methicillin-resistant Staphylococcus aureus (MRSA) carriage and furloughing MRSA-positive HCWs to prevent spread to patients is controversial. We evaluated our MRSA program for HCWs between 1992 and 2002. A university medical center in The Netherlands, where methicillin resistance has been kept below 0.5% of all nosocomial S. aureus infections using active surveillance cultures and isolation of colonized patients. HCWs caring for MRSA-positive patients or patients in foreign hospitals were screened for MRSA. MRSA-positive HCWs had additional cultures, temporary exclusion from patient-related work, assessment of risk factors for persisting carriage, decolonization therapy with mupirocin intranasally and chlorhexidine baths for skin and hair, and follow-up cultures. Fifty-nine HCWs were colonized with MRSA. Seven of 840 screened employees contracted MRSA in foreign hospitals; 36 acquired MRSA after contact with MRSA-positive patients despite isolation precautions (attack rate per outbreak varied from less than 1% to 15%). Our hospital experienced 17 MRSA outbreaks, including 13 episodes in which HCWs were involved. HCWs were index cases of at least 4 outbreaks. In 8 outbreaks, HCWs acquired MRSA after caring for MRSA-positive patients despite isolation precautions. Postexposure screening of HCWs allowed early detection of MRSA carriage and prevention of subsequent transmission to patients. Where the MRSA prevalence is higher, the role of HCWs may be greater. In such settings, an adapted version of our program could help prevent dissemination.

Pneumonia in neutropenic patients.

Radiologists have a special role in the management of neutropenic patients. The appropriate investigational technique, frequently targeted differential diagnosis, and the special needs of these patients, need to be understood. Early detection of a focus is the major goal in febrile neutropenic patients. As pneumonia is the most common focus, chest imaging is a special radiological task. The sensitivity of chest X-ray, especially in supine position, is known to be low; therefore, the very sensitive high-resolution CT (HRCT) became gold standard in neutropenic hosts and will probably be replaced by thin-section multislice CT (MSCT) in the near future. Costs of high-resolution CT are low in comparison to antibiotics. An infiltrate needs to be localised, so that a physician can utilise this information as a guidance for invasive procedures for further microbiological work-up. The radiological characterisation of infiltrates gives a first and rapid hint to differentiate between different sorts of infectious (typical bacterial, atypical bacterial, fungal) and non-infectious aetiologies. Follow-up investigations need careful interpretation according to disease and concomitant treatment. Due to an increased incidence of fungal infiltrates even with appropriate therapy, follow-up of an infiltrate must use further parameters in addition to lesion size. Temporary exclusion of infectious involvement of the lung with high accuracy remains of special interest for clinicians.

Pyopneumothorax à Candida albicans révélant une perforation spontanée de l’œsophage

Oesophagus perforation, despite an often-loud symptomatology, is lately diagnosed. A similar course is illustrated by the observation of a patient who presented a Candida albicans-induced empyema. The oesophagus rupture was diagnosed by thoracoscopy made because of extensive hydropneumothorax on the thoracic CT 3 days after ablation of the thoracic drain. Temporary oesophagus exclusion and pleural drainage in close proximity of the perforation were performed. A nosocomial pneumonia complicated the development but the patient could endly issue from ICU. This mode of revelation was unusual and the authors recommend thinking of the diagnosis of oesophagus rupture when a patient is admitted for a candidosis empyema.

Maintaining cognitive function with diet.

The issue of postoperative disorders of cognitive functions is a highly topical problem as more and more elderly people undergo medical treatments. Patients may lose the ability of assimilating information and their linguistic functions may deteriorate. Cognitive disorders may result in the temporary exclusion of the patient from social activity.The purpose of the paper was to assess the incidence of certain cognitive disorders in the elderly after urological surgeries.The study was conducted in a group of 218 patients aged over 65, male and female, after an urological surgery under different types of anesthesia. Standardized neuropsychological tests of cognitive functions were employed in the study.Analysis of the data showed that in the control group were obtained similar results in the study of the first and second. However, in the test group demonstrated a reduction cognitive function in all the tests in a second study.The reduction of cognitive functions in the study group was observed in all the domains but it was the most marked in visual memory tests. Postoperative reduction of cognitive functions is correlated with the patient's age, education and mood. Postoperative reduction of cognitive functions is not correlated with the type of surgery, anesthesia and its duration.

Temporary neurological dysfunction after deep hypothermic circulatory arrest: a clinical marker of long-term functional deficit

Background. With increasing clinical experience, it has become clear that two distinct forms of neurological injury occur after operations on the thoracic aorta that require temporary exclusion of the cerebral circulation. Traditionally, evaluation of neurological outcome was limited to reporting the incidence of postoperative stroke related to ischemic infarcts due to particulate embolization. More recently, the symptom complex defined as “temporary neurological dysfunction” (TND) was recognized as a functional manifestation of subtle and presumably transient brain injury, but whether this early postoperative syndrome is associated with long-term deficits of cognitive and intellectual functions has not been established. Methods. With Institution Review Board approval, 105 patients undergoing elective thoracic aortic surgery were entered into a protocol involving neuropsychological evaluation with a battery of tests preoperatively, and 1 and 6 weeks postoperatively. Patients who could not be tested adequately or had documented strokes were eliminated from final analysis. Seventy-one patients completed the neuropsychological evaluation, which consisted of eight tests consolidated into five domains: attention, cognitive speed, memory, executive function, and fine motor function. Independent observers also determined whether temporary dysfunction was present, and graded its severity based on a fixed but subjective clinical scale, ranging from simple disorientation and lethargy or confusion (grade 1–2) to prolonged extreme agitation or psychotic behavior requiring treatment with psychotropic drugs (grade 3–5). Data were normalized to baseline values, and were analyzed using analysis of variance, analysis of covariance (ANCOVA), and χ 2 as necessary. Results. A previous analysis had shown that patients who could not be tested or had poor scores 1 week postoperatively were more likely to perform poorly at 6 weeks (odds ratio 5.27, p < 0.01). In the current study, in order to determine the clinical relevance of TND, patients were analyzed retrospectively according to their performance in neuropsychological testing: patients with no change or a decline of less than 50% in tests of memory, motor function, and attention 1 week postoperatively (group 1, n = 49) were compared with those with a negative change exceeding 50% in the same functions at 1 week (group 2, n = 22). The overall incidence of TND was 28.1% (20/71). The incidence of TND in group 2 (14/22, 63%) was significantly higher than in group 1 (6/49, 12%; p = 0.0006). Similarly, the severity of TND (as assessed by clinical score > 2) was also significantly higher in group 2 (11/14) compared with group 1 (0/6; p = 0.006.) Conclusions. The incidence and severity of clinically apparent temporary neurological dysfunction correlates significantly with poor performance on neuropsychological tests 1 week postoperatively. Such poor performance predicts continued deficits in memory and motor function at 6 weeks. Thus, TND may not be a benign self-limited condition as previously supposed, but rather a clinical marker for insidious but significant neurological injury associated with measurable long-term deficits in cerebral function. A concerted effort to reduce the incidence of this complication is therefore necessary.

Outclassed by Former Outcasts: Petty Trading in Varna

People caught in circumstances of social upheaval differ in the ways in which they adjust to instability and change. Occasionally individuals at less privileged socioeconomic levels engage in socially devalued practices such as the small‐scale trading enterprises that have been degraded ideologically during 45 years of communist rule in Bulgaria. In this article we explore the ways in which people adjust to change by examining ethnographically the practice of trader tourism in Bulgaria. We argue that such an examination supports a rethinking of the concept of boundaries, if boundaries are fluid sets of constraints that individuals negotiate when reacting to monumental stress. Specifically, we consider the reactions of population groups within Bulgaria to the post‐1989 economic crisis. We also suggest that members of each group react in group‐specific strategies of temporary inclusion, permanent inclusion, and exclusion, [economic anthropology, survival strategies, markets and trader tourism, capitalism con. communism, Roma/Indo‐Roma/Gypsies, Eastern Europe/Balkan/Bulgaria, transition/boundaries]

Experiments on the effects of water availability and exclusion of fungal hyphae on nutrient uptake and establishment of Pinus sylvestris seedlings in carpets of the moss Pleurozium schreberi

The feathermoss Pleurozium schreberi has the capacity to suppress tree seedling regeneration in late successional northern boreal forests. We investigated, through a field experiment in a P. schreberi-dominated old-growth Norway spruce forest in northern Sweden, the effects of three precipitation regimes representing the range of natural July precipitation amounts (28, 112 and 256 mm), and extra influences of temporary exclusion of fungal hyphae in senescent shoots of P. schreberi, on seedling establishment, growth and nutrient acquisition of Pinus sylvestris. Seedling establishment of Pinus sylvestris was enhanced by increased amounts of artificial precipitation. Seedlings in plots with the lowest precipitation had a much lower mortality and significantly higher total nutrient content, higher specific absorption rate (SAR) and lower nutrient use efficiency (NUE) compared to seedlings grown in plots with the highest precipitation. Seedling nutrient (especially N and P) content was also significantly higher when fungal hyphae were excluded, and this was most evident in treatments with the intermediate precipitation level. Seedlings in plots without hyphal isolation but with intermediate precipitation levels had much lower total contents of N, P and Mg after one growing season than were initially present in the seeds, indicative of a net nutrient loss during the early establishment phase. Possible rhizosphere interactions, causing immobilisation of nutrients and seedling nutrient losses are discussed in relation to results from greenhouse experiments where no such nutrient losses were found in seedlings. We hypothesize that P. schreberi, in association with ericaceous plants and fungal hyphae, is a powerful controller of tree regeneration from seeds over wide precipitation gradients, due to its inhibition of seedling establishment and strong interference with nutrient acquisition of new seedling cohorts.

MEGAPLANT: a simulation model of the dynamics of submerged plants

A generic simulation model for the dynamics of submerged macrophytes is presented, called MEGAPLANT (‘Model Evaluating General Aquatic Pland Laws And New Theories’). Although the model is kept relatively simple, it includes many aspects that have an effect on vegetation dynamics during the seasonal cycle, such as grazing, overwintering strategies, wave action and seed dispersal. The characteristics of both the plant and the environment can be adjusted by the user. The model is meant as an aid to enhance insight into the interplay of processes that influence vegetation dynamics. As an example, it is used to analyze mechanisms that determine the survival of vegetation in turbid eutrophic lakes. The following results were found. (1) Hot spots of propagule-producing vegetation can permanently maintain vegetation stands at sites that would otherwise be devoid of macrophytes. (2) Moderate fluctuations in environmental factors that normally have little impact on the vegetation can cause large year-to-year fluctuations in biomass of vegetation growing under suboptimal conditions. (3) Grazing by herbivores such as coots can cause the existence of two alternative stable states: under-exploited and overgrazed. This implies that herbivores may prevent the recovery of submerged macrophytes in lakes that are recovering from eutrophication, but also that temporary exclusion of herbivores can trigger permanent recovery of the vegetation.It is shown that the quantitative simulation results are sensitive to the setting of several parameters but that the qualitative results presented are quite robust against changes in parameter setting. It is argued that although the prospects of accurate predictive simulation of aquatic vegetation are poor, relatively simple models like the one presented can be a useful tool to improve the theoretical framework for understanding the dominant mechanisms regulating submerged plant dynamics.

Transmission of Escherichia coli 0157:H7 Infection in Minnesota Child Day-care Facilities

Escherichia coli O157:H7 infection can cause hemorrhagic colitis and hemolytic uremic syndrome. Since 1988 the Minnesota Department of Health has carried out surveillance for this infection. To assess the occurrence of person-to-person transmission within day-care facilities, we investigated facilities where an infected child attended after onset of symptoms. Parents of children less than 5 years old with E coli O157:H7 infection were interviewed from July 1988 through December 1989. If the child attended day care after onset, stool cultures were obtained from other children in attendance and their parents were interviewed. If there was presumptive evidence of ongoing E coli O157:H7 transmission in a facility, all preschool children were excluded from attending day-care facilities until two consecutive stool cultures were negative. Sixty-eight cases of E coli O157:H7 infection were identified in Minnesota during the 18-month period, including 29 cases identified through investigations at nine day-care facilities. There was evidence of person-to-person transmission in all nine facilities. The median number of infected children per facility was two (range, two to 18), and the median attack rate was 22% (range, 3% to 38%). The median age of the primary case at each facility was 26 months (range, 12 to 59 months). There was no evidence of further transmission at facilities where children were temporarily excluded until two consecutive stool cultures were negative. Person-to-person transmission of E coli O157:H7 is common when infected preschool children attend day care while symptomatic. The number of unrecognized day-care outbreaks in the United States may be substantial due to the lack of routine testing for this pathogen in stool cultures, the absence of public health surveillance in many regions, and incomplete follow-up of infected children. Temporary exclusion of all children was an effective control strategy in this population, but additional investigations are needed to determine the optimal intervention.

Acute Unilateral Renal Failure and Contralateral Ureteral Obstruction

After obstetrical surgery, a young woman developed an acute renal failure of one kidney, the other having been protected by a fortuitous ureteral ligation. The possible effects of a temporary kidney exclusion on itself and on the other kidney are discussed.

Conjunctivitis in Clean Room Workers

Conjunctivitis, in the industrial setting, can be attributed to eye contact with contaminated microscope oculars. Establishing a simple, convenient process for cleaning microscope oculars as well as educating employees and their management is important to reduce risk of contamination. Early identification and treatment of an isolated infection by the occupational health nurse and temporary exclusion from microscope work is essential in controlling the spread of infection and preventing a potential epidemic. The occupational health nurse plays a pivotal role in the recognition of and response to workplace health concerns and development of targeted strategies to promote and maintain health in the workplace.

A Model for Determining the Influence of Hepatic Uptake of Nondepolarizing Muscle Relaxants in the Pig

Hepatic uptake and distribution of nondepolarizing muscle relaxants in pigs was investigated. A portocaval shunt preparation enabled the determination of the pharmacodynamics of nondepolarizing muscle relaxants both during temporary liver exclusion and intraportal injection in the same animal. To demonstrate the validity of the model in pigs, in a pilot study the influence of hepatic uptake on neuromuscular blockade by pancuronium (n = 3) and its congener Org 6368 (n = 3) was determined. Thereafter, the influence of hepatic uptake on neuromuscular blockade by gallamine (3.4 mg/kg, n = 5), Org 6368 (0.3 mg/kg, n = 5), and vecuronium (0.1 mg/kg, n = 4 and 0.15 mg/kg, n = 5) was studied in pigs anesthetized with pentobarbital. Each pig received one relaxant, which was injected four consecutive times under different conditions. The first injection was into the jugular vein (iv) the second into the portal vein, the third was iv while the liver was excluded for 10 min and the fourth was iv (control). After each injection the onset time, intensity, recovery rate, and total duration of neuromuscular blockade were measured. These variables were compared between the four injections for each relaxant. In the pilot study the influence of hepatic uptake on neuromuscular blockade was similar for pancuronium and Org 6368. For gallamine the onset time, intensity, recovery rate, and duration of action were similar after all four injections. For Org 6368 the variables of neuromuscular blockade were similar after iv and intraportal injection, but exclusion of the liver prolonged the neuromuscular block.(ABSTRACT TRUNCATED AT 250 WORDS)

Recovery of forelimb voluntary movement following reinnervation of forelimb muscles by respiratory nerve in the cat

A study of spontaneous head posture and of righting of the head after hemilabyrinthectomy appears to be a good way to describe the time course of postural compensation. This chapter uses this index in animals recovering in normal conditions, and in animals submitted to a temporary exclusion of visual input during the postoperative stage. By varying the duration of the visual deprivation period, and its position in time with respect to the operation, it becomes possible to alter the normal process of recovery and consequently to assess the role of vision in re-acquisition and/or in maintenance of the new postural compensation. Compensation in normal postoperative conditions begins during the first week with a strong inhibition of the resting activity in the vestibular nuclei on both sides. The evolution is then marked by a progressive regeneration of activity in the vestibular nuclei on the deafferented side (presumably via an increase in excitatory synaptic efficacy of the commissural system), and later by a disinhibition on the normal side. It is inferred that static visual input is a necessary condition for compensation of the postural deficits of hemilabyrinthectomy in animals. Maintenance of a stable head posture also depends upon continuous availability of visual input.

An analysis of the compensatory process in the hemilaby-rinthectomized cat using the [ 14C] DG method

A study of spontaneous head posture and of righting of the head after hemilabyrinthectomy appears to be a good way to describe the time course of postural compensation. This chapter uses this index in animals recovering in normal conditions, and in animals submitted to a temporary exclusion of visual input during the postoperative stage. By varying the duration of the visual deprivation period, and its position in time with respect to the operation, it becomes possible to alter the normal process of recovery and consequently to assess the role of vision in re-acquisition and/or in maintenance of the new postural compensation. Compensation in normal postoperative conditions begins during the first week with a strong inhibition of the resting activity in the vestibular nuclei on both sides. The evolution is then marked by a progressive regeneration of activity in the vestibular nuclei on the deafferented side (presumably via an increase in excitatory synaptic efficacy of the commissural system), and later by a disinhibition on the normal side. It is inferred that static visual input is a necessary condition for compensation of the postural deficits of hemilabyrinthectomy in animals. Maintenance of a stable head posture also depends upon continuous availability of visual input.

Impact of the artificial lung on medical care

Mechanical systems to oxygenate blood outside of the body were first employed in clinical medicine as a component of the "heart-lung machine". The artificial lung has been an essential component of the technology underlying the progress of cardiovascular surgery since 1950. Its impact on clinical medicine can be measured by the widespread acceptance of cardiac surgery for the treatment first of congenital malformations, then valvular lesions, and more recently, coronary artery disease. Whereas the use of the artificial lung during temporary exclusion of the pulmonary circulation for surgical purposes is now well established, the chronic application of extracorporeal membrane oxygenation and end-stage resporatory failure is still controversial. Internally implantable lung prostheses are still at the conceptual or developmental stage, and are unlikely to impact on clinical medicine for another decade.

Recovery of electrical activity of anterior abdominal wall muscles after prolonged atrophy

In experiments on anesthetised and awake cats the dynamics of the cerebral blood flow was studied by the thermoelectric method in one hemisphere in experimental lesion of the somatosensory zone of the opposite one. Temporary exclusion of the cortical area by cold produced evident hemodynamic changes, i. e. a two-phase vasoreaction and an initial blood flow decrease followed by a prolonged increase of blood supply, in the other hemisphere. Analogous vasoreactions were seen on unilateral extirpation of the cortical layer of the somatosensory zone, as well. Such vasoreactions indicate enhanced activity of the cortical structures in the intact hemisphere and may be considered as a compensatory reaction to the local lesion of certain cortical areas.

Visual Substitution of Labyrinthine Defects

A study of spontaneous head posture and of righting of the head after hemilabyrinthectomy appears to be a good way to describe the time course of postural compensation. This chapter uses this index in animals recovering in normal conditions, and in animals submitted to a temporary exclusion of visual input during the postoperative stage. By varying the duration of the visual deprivation period, and its position in time with respect to the operation, it becomes possible to alter the normal process of recovery and consequently to assess the role of vision in re-acquisition and/or in maintenance of the new postural compensation. Compensation in normal postoperative conditions begins during the first week with a strong inhibition of the resting activity in the vestibular nuclei on both sides. The evolution is then marked by a progressive regeneration of activity in the vestibular nuclei on the deafferented side (presumably via an increase in excitatory synaptic efficacy of the commissural system), and later by a disinhibition on the normal side. It is inferred that static visual input is a necessary condition for compensation of the postural deficits of hemilabyrinthectomy in animals. Maintenance of a stable head posture also depends upon continuous availability of visual input.

The use of pyloric exclusion in the management of severe duodenal injuries

Repair of severe duodenal injuries often constitutes a technical challenge, and a variety of special technics have been described. For the past seven years we have utilized temporary pyloric exclusion and gastrojejunostomy to produce “diverticulization” of the duodenum. This procedure was utilized in seventy-five patients selected from 175 consecutive patients presenting with duodenal trauma. The mortality was 19 per cent and the rate of fistula formation was 5 per cent in this series and 14 per cent and 2 per cent, respectively, in the overall series. Follow-up studies of gastric physiology and functional anatomy show no evidence of alteration of these parameters. We thus believe that patients presenting with severe duodenal trauma and often multiple devastating associated organ injuries can be adequately treated with this procedure with a significant decrease in mortality and with marked improvement of postoperative morbidity.