PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Dynamic risk”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources
PubMed1993

[Does a hypertensive reaction to dynamic exercise imply an increased risk of developing essential hypertension?].

Early diagnosis of essential hypertension, preferably in the pre-hypertensive stage, is very important for the prognosis of affected subjects. Based on sporadic information in the literature it seems that people who are normotensive at rest but have an exaggerated hypertensive reaction to exercise have a greater risk of developing essential hypertension in future. The authors selected from protocols of ECG exercise tests a group of subjects with normal blood levels at rest but an exaggerated hypertensive reaction to a dynamic exercise. The control group was formed by people with a normal pressure reaction to a exercise the control group was matched as regards age, sex and basic anthropometric parameters. After a mean period of 7.8 years (range 5-10 years) it was revealed that while in the control group hypertension was manifested in 10%, in the group with an exaggerated hypertensive reaction to an exercise it was manifested in 33.3%. The mean original blood pressure readings at rest were significantly higher in people with a normal blood pressure reaction to an exercise and this difference persisted also at the end of the investigation. An exaggerated hypertensive reaction to a dynamic exercise is one of the prognostic factors for the development of essential hypertension and should be a reason for follow-up.

Adult↗
PubMedDate not supplied

Rotator cuff ultrasonography: diagnostic capabilities.

Dynamic shoulder ultrasonography is a noninvasive, accurate method used to assess the rotator cuff tendons. It can be incorporated into the in-office physical examination of patients at risk for rotator cuff problems. The low cost, convenience, and lack of risk make dynamic ultrasonography an excellent imaging tool for evaluating the biceps, subscapularis, infraspinatus, teres minor, and supraspinatus tendons. In-office ultrasound also provides an opportunity for patient education and explanation of management options.

Diagnosis, Differential↗
PubMed2002

Health risk escalators and the rehabilitation of offenders with learning disabilities.

This paper presents a study of risk management in a hospital within the UK. National Health Service which attempts to rehabilitate offenders with learning disabilities. Analysis is based on the metaphor of a 'risk escalator'. Health and social care systems can be characterised as risk escalators if they possess three attributes. Firstly, risk managers should agree the rough ordering of the severity of a set of related risks. Secondly, a repertoire of responses which provide different trade-offs between autonomy and safety, and which can be calibrated against risk severity, should be available. Thirdly, the potential for positive and/or negative feedback, which give risk escalators their dynamic character, should be identified. Risk escalators may be deliberately designed, or may, like the hospital regime discussed in this paper, coalesce from pre-existing sub-systems offering different autonomy/safety balances. They may carry service users upwards towards greater safety if needed, as in health screening systems, or downward towards greater autonomy if justified, for instance in rehabilitation systems. Their therapeutic status is contestable. Upward risk escalators can be accused of generating positive feedback, with iatrogenic effect. Downward risk escalators may be criticised for pushing service users too strongly towards less intense interventions, causing neglect. The present case study brings out emergent properties of a downward risk escalator, including: organisational disruption to system functioning; preferencing of safety over autonomy; active and reflexive system management by clients; multiple, organisational risk rationalities; and the reification of riskiness as a generic attribute of individuals.

Crime↗
PubMed2003

Comparative survival of Cryptosporidium, coxsackievirus A9 and Escherichia coli in stream, brackish and sea waters.

Discharge of inadequately treated wastewater into streams may result in the dissemination of pathogens and the contamination of surface water sources. Determining the die-off rate of pathogenic microorganisms in stream and sea waters may serve as the basis for evaluating the health risks posed by the presence of pathogens in seawater. This study was conducted to determine the effect of microbial load, temperature, salinity and turbidity on the die-off of oocysts of Cryptosporidium as compared to that of coxsackie A9 virus (Cox A9) and E. coli. The test microorganisms were seeded into stream, outfall or sea waters and incubated at either 30 degrees C (summer) or 15 degrees C (winter). At 30 degrees C, the fastest die-off was observed for Cox A9 where < 5-log was reduced regardless of the water quality. At 1 degrees C Cox A9 persistence was similar to that of Cryptosporidium where no change was detected in the concentration of either throughout the study period. E. coli die-off reached 5 orders of magnitude within 10d then its concentration remained unchanged. The die-off of E. coli was faster than observed for Cox A9 at 15 degrees C regardless of the water quality. No decrease was observed in the viability of Cryptosporidium under all tested conditions throughout the study period indicating the unsuitability of E. coli to serve as an indicator for the presence of parasites and viruses in stream and marine waters. The prolonged persistence of pathogenic microorganisms in marine waters suggested that discharge of contamination into streams may present a serious environmental health risk.

Animals↗
PubMed2005

Modelling salmon lice dispersal in Loch Torridon, Scotland.

A particle transport model is described that is being used to simulate the dispersal of salmon lice (Lepeophtheirus salmonis) larvae in the waters of Loch Torridon. A hydrodynamic model, forced by tides and winds, drives the transport model. Particle movements are strongly influenced by winds, which can lead to formation of lice concentrations in coastal areas several kilometres from the source. Idealised constant wind simulations have been used to locate areas that larval lice may potentially reach from given source locations. Detailed analysis of simulations forced with real wind data is required to assess areas that larval lice from these sources are likely to reach. Further field and experimental work on the viability of lice is required to assess infection risk.

Animals↗
PubMed2001

The treatment of subcapital humerus fracture with dynamic helix wire and the risk of concommitant lesion of the axillary nerve.

Displaced subcapital fractures of the humerus represent a therapeutic challenge for the surgeon, all the more so because of their high incidence among osteoporotic patients. Open surgical repair involves increased risk of avascular necrosis of the humeral head, while percutaneous reduction and fixation often fails as a result of loosening pins. As a possible solution, a minimally invasive technique was developed in which a dynamic titanium wire helix is inserted into the medullary space of the diaphysis of the humerus and then rotated proximally into the head fragment. This new approach for osteosynthesis was performed in 84 patients, most of whom had suffered two- or three-part fractures. Results were evaluated by the Constant Functional Score, indicating an average 87% rehabilitation. An associated anatomical study of 53 human cadavers investigated the position of the main branches of the axillary nerve relative to the surgical placement of the wire helix. In all cases, the distance between the most vulnerable anterior branch of the axillary nerve (ABAN) and the operative site was sufficient, as long as insertion occurs in the distal third of the distance between the head of the humerus and the deltoid tuberosity. Utilization of the titanium helix results in prompt healing of subcapital fractures while offering minimal risk for the elderly osteoporotic patient and does not endanger branches of the axillary nerve.

Aged↗
PubMed2005

[Impact of population exposure on the risk of bacterial resistance].

Exposure of populations to antibiotics is a condition for the emergence and the diffusion of bacteria resistant to antibiotics. Analysis of epidemiological causality between antibiotic exposure and expansion of antibiotic resistance in human pathogens requires the study of the basis for the emergence and the subsequent epidemic spread of the strains. Emergence of antibiotic resistance under the selective pressure of antibiotics is unavoidable. However, the rapidity of the emergence depends on several parameters including the biochemical mechanism and the genetic support of the resistance and on the couple bacteria/antibiotic considered. Several of these parameters may be studied and measured in vitro. In vivo, relationship between antibiotic exposure and risk for infection or colonisation by pneumococci resistant to beta-lactams or macrolides and methicillin-resistant staphylococci are among the best studied models. In particular for pneumococci, quantitative relationship between antibiotic consumption and resistance, including geographical correlations have been shown but do not allow to establish any causality relationship. Overall, there is no doubt on the question of the impact of antibiotic exposure and the risk of antibiotic resistance. However, the quantification of the risks remains to be accurately studied.

Anti-Bacterial Agents↗
PubMedDate not supplied

[Mortality in patients attending a psychiatric service].

This study followed during 10 years 322 Belgian patients aged between 20 and 39 years living in the district of Anderlecht and who had presented themselves for the first time to the psychosocial sector of this district between 1970 and 1973. Fifteen deaths were observed, 10 of which were among the under 30's. The S.M.R. observed (5.27) is similar to the results obtained in other international studies. The survival curves (Kaplan-Meier method) confirm the more considerable excess of mortality during the first years of the follow-up. The decreased sample was matched to a control sample of patients frequenting the centre and compared by the Mac Nemar test. There was very little difference between the two samples. The deceased had however rarely moved house during their follow-up and had accumulated a series of risk factors from the beginning.

Adult↗
PubMed1998

[The future of public health].

As the results of the structural reform policy regulating the health care sector, the paper presents the possible path of increasing intrasectoral risk selection and intersectoral risk externalization (especially between the law of health care insurance, the law of statutory nursing insurance, and the German poverty law). Particularly the new developments in the hospital sector will be analyzed regarding the dynamics of risk selection and risk externalization. The new economic ways of financing the hospital sector are inducing the need of systematic integration of the different branches of social law, especially more developed networks of the health care, the nursing system, and the social care services.

Aged↗
PubMed1997

Adaptation and extinction in changing environments.

The extinction risk of a population is determined by its demographic properties, the environmental conditions to which it is exposed, and its genetic potential to cope with and adapt to its environment. All these factors may have stochastic as well as directional components. The present chapter reviews several types of models concerned with the vulnerability of small populations to demographic stochasticity and to random and directional changes of the environment. In particular, the influence of mutation and genetic variability on the persistence time of a population is explored, critical rates for environmental change are estimated beyond which extinction on time scales of tens to a few thousand generations is virtually certain, and the extinction risks caused by the above mentioned factors are compared.

Adaptation, Physiological↗
PubMed2005

A risk-based predictive tool to prevent accidental introductions of nonindigenous marine species.

Preventing the introduction of nonindigenous species (NIS) is the most efficient way to avoid the costs and impacts of biological invasions. The transport of fouling species on ship hulls is an important vector for the introduction of marine NIS. We use quantitative risk screening techniques to develop a predictive tool of the abundance and variety of organisms being transported by ocean-going yachts. We developed and calibrated an ordinal rank scale of the abundance of fouling assemblages on the hulls of international yacht hulls arriving in New Zealand. Fouling ranks were allocated to 783 international yachts that arrived in New Zealand between 2002 and 2004. Classification tree analysis was used to identify relationships between the fouling ranks and predictor variables that described the maintenance and travel history of the yachts. The fouling ranks provided reliable indications of the actual abundance and variety of fouling assemblages on the yachts and identified most (60%) yachts that had fouling on their hulls. However, classification tree models explained comparatively little of the variation in the distribution of fouling ranks (22.1%), had high misclassification rates (approximately 43%), and low predictive power. In agreement with other studies, the best model selected the age of the toxic antifouling paint on yacht hulls as the principal risk factor for hull fouling. Our study shows that the transport probability of fouling organisms is the result of a complex suite of interacting factors and that large sample sizes will be needed for calibration of robust risk models.

Animals↗
PubMed2002

Application of an ecosystem model for aquatic ecological risk assessment of chemicals for a Japanese lake.

The Lake Suwa version of the comprehensive aquatic systems model (CASM-SUWA) was developed using field data from Lake Suwa and evaluated to examine the utility of CASM-SUWA for assessing the ecological risk of chemicals for aquatic ecosystems. The calibration of the parameters for the model provided that the established reference model simulation could reproduce complex seasonal biomass behavior of populations that were not significantly different from the general seasonal pattern for the Lake Suwa ecosystem. The sensitivity analyses revealed the potential importance of indirect effects and demonstrated that the parameter values of all the trophic levels were important in determining the biomass of each trophic level in the model. The risk estimation of linear alkylbenzene sulfonates (LAS) demonstrated that the model estimated the risks of direct toxic effects on each population and the indirect ecological effects that propagate through the food-web in the model ecosystem. The CASM-SUWA-derived benchmark levels were approximately one order of magnitude less than the field-derived NOECs in literature. The analyses of the comparison implied that the model could provide a good basis in determining an ecological protective level of a chemical of concern in aquatic ecosystem. This modeling study demonstrated that the model can be used to provide additional information for the decision-making process in the management of the aquatic ecological risk of chemicals.

Benchmarking↗
PubMed2002

Potential effect of population and climate changes on global distribution of dengue fever: an empirical model.

BACKGROUND: Existing theoretical models of the potential effects of climate change on vector-borne diseases do not account for social factors such as population increase, or interactions between climate variables. Our aim was to investigate the potential effects of global climate change on human health, and in particular, on the transmission of vector-borne diseases. METHODS: We modelled the reported global distribution of dengue fever on the basis of vapour pressure, which is a measure of humidity. We assessed changes in the geographical limits of dengue fever transmission, and in the number of people at risk of dengue by incorporating future climate change and human population projections into our model. FINDINGS: We showed that the current geographical limits of dengue fever transmission can be modelled with 89% accuracy on the basis of long-term average vapour pressure. In 1990, almost 30% of the world population, 1.5 billion people, lived in regions where the estimated risk of dengue transmission was greater than 50%. With population and climate change projections for 2085, we estimate that about 5-6 billion people (50-60% of the projected global population) would be at risk of dengue transmission, compared with 3.5 billion people, or 35% of the population, if climate change did not happen. INTERPRETATION: We conclude that climate change is likely to increase the area of land with a climate suitable for dengue fever transmission, and that if no other contributing factors were to change, a large proportion of the human population would then be put at risk.

Aedes↗
PubMed2004

The influence of seatback characteristics on cervical injury risk in severe rear impacts.

The determination of the optimum seatback characteristics for the mitigation of serious and catastrophic neck injury during high-speed rear-end collisions remains a topic of continued investigation. Despite a number of prior research efforts, both field data and sled test studies have yet to define a single optimal seatback performance criterion. Further, recent developments in seatbacks have introduced new designs into the field that have not been compared to more traditional designs. Analysis of NASS data from 1980 to 1999 demonstrated that at changes in velocity (DeltaV) above 40 kph, rear-end collisions have a dramatically lower risk for catastrophic injury than frontal, near-side or far-side impacts. Unfortunately, owing to the small penetration of newer seatback designs in the automotive fleet, it is not possible to examine the influence of seatback design parameters on serious neck injury using these data alone. Accordingly, seven rear impact HYGE sled tests were conducted using a wide range of seat designs. Upper and lower neck load cells were used to measure neck forces and moments in restrained 50th male Hybrid III anthropomorphic test devices (ATD). Additionally, the neck injury criteria (Nij) was computed. Unlike prior studies that have examined the standard seated ATD or the dramatically out-of-position ATD, these tests were conducted using an ATD seated in non-standard but typical driving position. The results of this study indicate that several descriptions of seatback behavior, such as quasi-static ultimate force are poor predictors of ATD neck loading. It also suggests that, for the severe crash studied, an optimum range of seatback stiffness exists, which appears to be in the mid-range of seatback stiffnesses available in current production vehicles. These data continue to illustrate the complex relationship of seatback design parameters to neck injury risk.

Accidents, Traffic↗
PubMed1986

Epidemiological considerations in the treatment of hypertension.

Cardiovascular disease continues to be the principal cause of death in Western countries. Epidemiological studies have repeatedly demonstrated a striking relationship between blood pressure and the risk of cardiovascular disease in that those with the highest levels of blood pressure are at the greatest risk for subsequent disease or death. However, most blood pressure-related cardiovascular complications occur at much lower levels of blood pressure. Any attempt to substantially reduce the frequency of blood pressure-related cardiovascular disease mandates treatment of large numbers of asymptomatic subjects who are, on average, only exposed to a slight increase in risk. Based on current demographic trends, this requirement will become even more striking in the future. Non-pharmacological interventions provide the most attractive approach to the prevention and treatment of high blood pressure. However, the efficacy and acceptability of long term non-drug treatment is uncertain. Drug treatment remains the best proven and fundamental approach to the treatment of established hypertension. Based on the lifelong nature of antihypertensive therapy and the changing risk profile of those being treated, a desire to recognise and prevent adverse effects of antihypertensive drug administration is now more important than ever. Special care is essential during the treatment of uncomplicated mild hypertensives with few or no other cardiovascular risk factors.

Age Factors↗