961 resultados para Risk aversion
Resumo:
Recommendations - 1 To identify a person with diabetes at risk for foot ulceration, examine the feet annually to seek evidence for signs or symptoms of peripheral neuropathy and peripheral artery disease. (GRADE strength of recommendation: strong; Quality of evidence: low) - 2 In a person with diabetes who has peripheral neuropathy, screen for a history of foot ulceration or lower-extremity amputation, peripheral artery disease, foot deformity, pre-ulcerative signs on the foot, poor foot hygiene and ill-fitting or inadequate footwear. (Strong; Low) - 3 Treat any pre-ulcerative sign on the foot of a patient with diabetes. This includes removing callus, protecting blisters and draining when necessary, treating ingrown or thickened toe nails, treating haemorrhage when necessary and prescribing antifungal treatment for fungal infections. (Strong; Low) - 4 To protect their feet, instruct an at-risk patient with diabetes not to walk barefoot, in socks only, or in thin-soled standard slippers, whether at home or when outside. (Strong; Low) - 5 Instruct an at-risk patient with diabetes to daily inspect their feet and the inside of their shoes, daily wash their feet (with careful drying particularly between the toes), avoid using chemical agents or plasters to remove callus or corns, use emollients to lubricate dry skin and cut toe nails straight across. (Weak; Low) - 6 Instruct an at-risk patient with diabetes to wear properly fitting footwear to prevent a first foot ulcer, either plantar or non-plantar, or a recurrent non-plantar foot ulcer. When a foot deformity or a pre-ulcerative sign is present, consider prescribing therapeutic shoes, custom-made insoles or toe orthosis. (Strong; Low) - 7 To prevent a recurrent plantar foot ulcer in an at-risk patient with diabetes, prescribe therapeutic footwear that has a demonstrated plantar pressure-relieving effect during walking (i.e. 30% relief compared with plantar pressure in standard of care therapeutic footwear) and encourage the patient to wear this footwear. (Strong; Moderate) - 8 To prevent a first foot ulcer in an at-risk patient with diabetes, provide education aimed at improving foot care knowledge and behaviour, as well as encouraging the patient to adhere to this foot care advice. (Weak; Low) - 9 To prevent a recurrent foot ulcer in an at-risk patient with diabetes, provide integrated foot care, which includes professional foot treatment, adequate footwear and education. This should be repeated or re-evaluated once every 1 to 3 months as necessary. (Strong; Low) - 10 Instruct a high-risk patient with diabetes to monitor foot skin temperature at home to prevent a first or recurrent plantar foot ulcer. This aims at identifying the early signs of inflammation, followed by action taken by the patient and care provider to resolve the cause of inflammation. (Weak; Moderate) - 11 Consider digital flexor tenotomy to prevent a toe ulcer when conservative treatment fails in a high-risk patient with diabetes, hammertoes and either a pre-ulcerative sign or an ulcer on the distal toe. (Weak; Low) - 12 Consider Achilles tendon lengthening, joint arthroplasty, single or pan metatarsal head resection, or osteotomy to prevent a recurrent foot ulcer when conservative treatment fails in a high-risk patient with diabetes and a plantar forefoot ulcer. (Weak; Low) - 13 Do not use a nerve decompression procedure in an effort to prevent a foot ulcer in an at-risk patient with diabetes, in preference to accepted standards of good quality care. (Weak; Low)
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Uncertainty plays an important role in water quality management problems. The major sources of uncertainty in a water quality management problem are the random nature of hydrologic variables and imprecision (fuzziness) associated with goals of the dischargers and pollution control agencies (PCA). Many Waste Load Allocation (WLA)problems are solved by considering these two sources of uncertainty. Apart from randomness and fuzziness, missing data in the time series of a hydrologic variable may result in additional uncertainty due to partial ignorance. These uncertainties render the input parameters as imprecise parameters in water quality decision making. In this paper an Imprecise Fuzzy Waste Load Allocation Model (IFWLAM) is developed for water quality management of a river system subject to uncertainty arising from partial ignorance. In a WLA problem, both randomness and imprecision can be addressed simultaneously by fuzzy risk of low water quality. A methodology is developed for the computation of imprecise fuzzy risk of low water quality, when the parameters are characterized by uncertainty due to partial ignorance. A Monte-Carlo simulation is performed to evaluate the imprecise fuzzy risk of low water quality by considering the input variables as imprecise. Fuzzy multiobjective optimization is used to formulate the multiobjective model. The model developed is based on a fuzzy multiobjective optimization problem with max-min as the operator. This usually does not result in a unique solution but gives multiple solutions. Two optimization models are developed to capture all the decision alternatives or multiple solutions. The objective of the two optimization models is to obtain a range of fractional removal levels for the dischargers, such that the resultant fuzzy risk will be within acceptable limits. Specification of a range for fractional removal levels enhances flexibility in decision making. The methodology is demonstrated with a case study of the Tunga-Bhadra river system in India.
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Depending on how they perceive risk, consumers may not always act according to their ethical beliefs, exposing a gap between beliefs and behavior. We investigate the effect of moral potency on perceived psychological risk of committing an unacceptable behavior. The results suggest that perceived risk is triggered by moral ownership.
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Physicochemical characterization of freshwater samples from Finland, Sweden, the Netherlands, and Spain revealed that water hardness and pH decreased and the quantity and quality of humic substances changed considerably in this geographical series from south to north. Since the ambient water chemistry may affect the availability of chemicals, the total aqueous concentration of a chemical may be insufficient to predict the bioconcentration, subsequent biological response, and thus risk. In addition, organisms could be affected directly by water quality characteristics. In this context the main objective of this thesis was to investigate the bioavailability of selected ecotoxicologically relevant chemicals (cadmium, benzo(a)pyrene, and pyrene) in various European surface waters and to show the importance of certain water chemistry characteristics in interpreting the bioavailability and toxicity results. The bioavailability of cadmium to Daphnia magna was examined in very soft humic lake water. Humic substances as natural ligands decreased the free and bioavailable proportion of cadmium in soft lake water. As a consequence the uptake rate and the acute toxicity decreased compared with the humic-free reference. When the hardness of humic lake water was artificially elevated, the acute toxicity of cadmium decreased, although the proportion of free cadmium increased. The decreased bioavailability of cadmium in hard water was a result of effective competition for uptake by the hardness cations, especially calcium ions. The protective role of humic substances and water hardness against cadmium toxicity was also observed in Lumbriculus variegatus, although D. magna was more sensitive to cadmium. The bioavailability of two polycyclic aromatic hydrocarbons (PAHs), pyrene and benzo(a)pyrene, was studied in European surface waters of varying water chemistry. Humic substances acted as complexing ligands with both PAHs, but the bioavailability of the more lipophilic benzo(a)pyrene to D. magna was affected more by humic substances than that of pyrene. In addition, not only the quantity of humic substances, but also their quality affected the bioavailability of benzo(a)pyrene. Nevertheless, the humic substances played a protective role in the photo-enhanced toxicity of pyrene under UV-B radiation. Water hardness had no effect on pyrene toxicity. Results indicate that the typical physicochemical characteristics of boreal freshwaters should be considered carefully in local and regional risk assessment of chemicals concerning the Fennoscandian region.
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The paper presents an innovative approach to modelling the causal relationships of human errors in rail crack incidents (RCI) from a managerial perspective. A Bayesian belief network is developed to model RCI by considering the human errors of designers, manufactures, operators and maintainers (DMOM) and the causal relationships involved. A set of dependent variables whose combinations express the relevant functions performed by each DMOM participant is used to model the causal relationships. A total of 14 RCI on Hong Kong’s mass transit railway (MTR) from 2008 to 2011 are used to illustrate the application of the model. Bayesian inference is used to conduct an importance analysis to assess the impact of the participants’ errors. Sensitivity analysis is then employed to gauge the effect the increased probability of occurrence of human errors on RCI. Finally, strategies for human error identification and mitigation of RCI are proposed. The identification of ability of maintainer in the case study as the most important factor influencing the probability of RCI implies the priority need to strengthen the maintenance management of the MTR system and that improving the inspection ability of the maintainer is likely to be an effective strategy for RCI risk mitigation.
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Purpose The object of this paper is to examine whether the improvements in technology that enhance community understanding of the frequency and severity of natural hazards also increased the risk of potential liability of planning authorities in negligence. In Australia, the National Strategy imposes a resilience based approach to disaster management and stresses that responsible land use planning can reduce or prevent the impact of natural hazards upon communities. Design/methodology/approach This paper analyses how the principles of negligence allocate responsibility for loss suffered by a landowner in a hazard prone area between the landowner and local government. Findings The analysis in this paper concludes that despite being able to establish a causal link between the loss suffered by a landowner and the approval of a local authority to build in a hazard prone area, it would be in the rarest of circumstances a negligence action may be proven. Research limitations/implications The focus of this paper is on planning policies and land development, not on the negligent provision of advice or information by the local authority. Practical implications This paper identifies the issues a landowner may face when seeking compensation from a local authority for loss suffered due to the occurrence of a natural hazard known or predicted to be possible in the area. Originality/value The paper establishes that as risk managers, local authorities must place reliance upon scientific modelling and predictive technology when determining planning processes in order to fulfil their responsibilities under the National Strategy and to limit any possible liability in negligence.
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Indoor air quality is a critical factor in the classroom due to high people concentration in a unique space. Indoor air pollutant might increase the chance of both long and short-term health problems among students and staff, reduce the productivity of teachers and degrade the student’s learning environment and comfort. Adequate air distribution strategies may reduce risk of infection in classroom. So, the purpose of air distribution systems in a classroom is not only to maximize conditions for thermal comfort, but also to remove indoor contaminants. Natural ventilation has the potential to play a significant role in achieving improvements in IAQ. The present study compares the risk of airborne infection between Natural Ventilation (opening windows and doors) and a Split-System Air Conditioner in a university classroom. The Wells-Riley model was used to predict the risk of indoor airborne transmission of infectious diseases such as influenza, measles and tuberculosis. For each case, the air exchange rate was measured using a CO2 tracer gas technique. It was found that opening windows and doors provided an air exchange rate of 2.3 air changes/hour (ACH), while with the Split System it was 0.6 ACH. The risk of airborne infection ranged between 4.24 to 30.86 % when using the Natural Ventilation and between 8.99 to 43.19% when using the Split System. The difference of airborne infection risk between the Split System and the Natural Ventilation ranged from 47 to 56%. Opening windows and doors maximize Natural Ventilation so that the risk of airborne contagion is much lower than with Split System.
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Type 1 diabetes (T1D) is considered to be an autoimmune disease. The cause of T1D is the destruction of insulin-producing β-cells in the pancreatic islets. The autoimmune nature of T1D is characterized by the presence of autoreactive T-cells and autoantibodies against β-cell molecules. Insulin is the only β-cell-specific autoantigen associated with T1D but the insulin autoantibodies (IAAs) are difficult to measure with proper sensitivity. T-cell assays for detection of autoreactive T-cells, such as insulin-specific T-cells, have also proven to be difficult to perform. The genetic risk of T1D is associated with the HLA gene region but the environmental factors also play an important role. The most studied environmental risk factors of T1D are enteroviruses and cow's milk which both affect the immune system through the gut. One hypothesis is that the insulin-specific immune response develops against bovine insulin in cow's milk during early infancy and later spreads to include human insulin. The aims of this study were to determine whether the separation of immunoglobulin (Ig)G from plasma would improve the sensitivity of the IAA assay and how insulin treatment affects the cellular immune response to insulin in newly diagnosed patients. Furthermore, the effect of insulin concentration in mother's breast milk on the development of antibodies to dietary insulin in the child was examined. Small intestinal biopsies were also obtained from children with T1D to characterize any immunological changes associated with T1D in the gut. The isolation of the IgG fraction from the plasma of T1D patients negative for plasma IAA led to detectable IAA levels that exceeded those in the control children. Thus the isolation of IgG may improve the sensitivity of the IAA assay. The effect of insulin treatment on insulin-specific T-cells was studied by culturing peripheral blood mononuclear cells with insulin. The insulin stimulation induced increased expression of regulatory T-cell markers, such as Foxp3, in those patients treated with insulin than in patients examined before initiating insulin treatment. This finding suggests that insulin treatment in patients with T1D stimulates regulatory T-cells in vivo and this may partly explain the difficulties in measuring autoantigen-specific T-cell responses in recently diagnosed patients. The stimulation of regulatory T-cells by insulin treatment may also explain the remission period often seen after initiating insulin treatment. In the third study we showed that insulin concentration in mother's breast milk correlates inversely with the levels of bovine insulin-specific antibodies in those infants who were exposed to cow's milk proteins in their diet, suggesting that human insulin in breast milk induces tolerance to dietary bovine insulin. However, in infants who later developed T1D-associated autoantibodies, the insulin concentration in their mother's breast milk was increased. This finding may indicate that in those children prone to β-cell autoimmunity, breast milk insulin does not promote tolerance to insulin. In the small intestinal biopsies the presence of several immunological markers were quantified with the RT-PCR. From these markers the expression of the interleukin (IL)-18 cytokine was significantly increased in the gut in patients with T1D compared with children with celiac disease or control children. The increased IL-18 expression lends further support for the hypothesis that the gut immune system is involved in the pathogenesis of T1D.
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Glaucoma, optic neuropathy with excavation in the optic nerve head and corresponding visual field defect, is one of the leading causes for blindness worldwide. However, visual disability can often be avoided or delayed if the disease is diagnosed at an early stage. Therefore, recognising the risk factors for development and progression of glaucoma may prevent further damage. The purpose of the present study was to evaluate factors associated with visual disability caused by glaucoma and the genetic features of two risk factors, exfoliation syndrome (ES) and a positive family history of glaucoma. The present study material consisted of three study groups 1) deceased glaucoma patients from the Ekenäs practice 2) glaucoma families from the Ekenäs region and 3) population based families with and without exfoliation syndrome from Kökar Island. For the retrospective study, 106 patients with open angle glaucoma (OAG) were identified. At the last visit, 17 patients were visually impaired. Blindness induced by glaucoma was found in one or both eyes in 16 patients and in both eyes in six patients. The cumulative incidence of glaucoma caused blindness for one eye was 6% at 5 years, 9% at 10 years, and 15% at 15 years from initialising the treatment. The factors associated with blindness caused by glaucoma were an advanced stage of glaucoma at diagnosis, fluctuation in intraocular pressure during treatment, the presence of exfoliation syndrome, and poor patient compliance. A cross-sectional population based study performed in 1960-1962 on Kökar Island and the same population was followed until 2002. In total 965 subjects (530 over 50 years) have been examined at least once. The prevalence of exfoliation syndrome (ES) was 18% among subjects older than 50 years. Seventy-five of all 78 ES-positives belonged to the same extended pedigree. According to the segregation and family analysis, exfoliation syndrome seemed to be inherited as an autosomal dominant trait with reduced penetrance. The penetrance was more reduced for males, but the risk for glaucoma was higher in males than in females. To find the gene or genes associated with exfoliation syndrome, a genome wide scan was performed for 64 members (28 ES affected and 36 controls) of the Kökar pedigree. A promising result was found: the highest two-point LOD score of 3.45 (θ=0.04) in chromosome18q12.1-21.33. The presence of mutations in glaucoma genes TIGR/MYOC (myocilin) and OPTN (optineurin) was analysed in eight glaucoma families from the Ekenäs region. An inheritance pattern resembling autosomal dominant mode was detected in all these families. Primary open angle glaucoma or exfoliation glaucoma was found in 35% of 136 family members and 28% were suspected to have glaucoma. No mutations were detected in these families.
Resumo:
Objective: To systematically review studies reporting the prevalence in general adult inpatient populations of foot disease disorders (foot wounds, foot infections, collective ‘foot disease’) and risk factors (peripheral arterial disease (PAD), peripheral neuropathy (PN), foot deformity). Methods: A systematic review of studies published between 1980 and 2013 was undertaken using electronic databases (MEDLINE, EMBASE and CINAHL). Keywords and synonyms relating to prevalence, inpatients, foot disease disorders and risk factors were used. Studies reporting foot disease or risk factor prevalence data in general inpatient populations were included. Included study's reference lists and citations were searched and experts consulted to identify additional relevant studies. 2 authors, blinded to each other, assessed the methodological quality of included studies. Applicable data were extracted by 1 author and checked by a second author. Prevalence proportions and SEs were calculated for all included studies. Pooled prevalence estimates were calculated using random-effects models where 3 eligible studies were available. Results: Of the 4972 studies initially identified, 78 studies reporting 84 different cohorts (total 60 231 517 participants) were included. Foot disease prevalence included: foot wounds 0.01–13.5% (70 cohorts), foot infections 0.05–6.4% (7 cohorts), collective foot disease 0.2–11.9% (12 cohorts). Risk factor prevalence included: PAD 0.01–36.0% (10 cohorts), PN 0.003–2.8% (6 cohorts), foot deformity was not reported. Pooled prevalence estimates were only able to be calculated for pressure ulcer-related foot wounds 4.6% (95% CI 3.7% to 5.4%)), diabetes-related foot wounds 2.4% (1.5% to 3.4%), diabetes-related foot infections 3.4% (0.2% to 6.5%), diabetes-related foot disease 4.7% (0.3% to 9.2%). Heterogeneity was high in all pooled estimates (I2=94.2–97.8%, p<0.001). Conclusions: This review found high heterogeneity, yet suggests foot disease was present in 1 in every 20 inpatients and a major risk factor in 1 in 3 inpatients. These findings are likely an underestimate and more robust studies are required to provide more precise estimates.
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Placental abruption, one of the most significant causes of perinatal mortality and maternal morbidity, occurs in 0.5-1% of pregnancies. Its etiology is unknown, but defective trophoblastic invasion of the spiral arteries and consequent poor vascularization may play a role. The aim of this study was to define the prepregnancy risk factors of placental abruption, to define the risk factors during the index pregnancy, and to describe the clinical presentation of placental abruption. We also wanted to find a biochemical marker for predicting placental abruption early in pregnancy. Among women delivering at the University Hospital of Helsinki in 1997-2001 (n=46,742), 198 women with placental abruption and 396 control women were identified. The overall incidence of placental abruption was 0.42%. The prepregnancy risk factors were smoking (OR 1.7; 95% CI 1.1, 2.7), uterine malformation (OR 8.1; 1.7, 40), previous cesarean section (OR 1.7; 1.1, 2.8), and history of placental abruption (OR 4.5; 1.1, 18). The risk factors during the index pregnancy were maternal (adjusted OR 1.8; 95% CI 1.1, 2.9) and paternal smoking (2.2; 1.3, 3.6), use of alcohol (2.2; 1.1, 4.4), placenta previa (5.7; 1.4, 23.1), preeclampsia (2.7; 1.3, 5.6) and chorioamnionitis (3.3; 1.0, 10.0). Vaginal bleeding (70%), abdominal pain (51%), bloody amniotic fluid (50%) and fetal heart rate abnormalities (69%) were the most common clinical manifestations of placental abruption. Retroplacental blood clot was seen by ultrasound in 15% of the cases. Neither bleeding nor pain was present in 19% of the cases. Overall, 59% went into preterm labor (OR 12.9; 95% CI 8.3, 19.8), and 91% were delivered by cesarean section (34.7; 20.0, 60.1). Of the newborns, 25% were growth restricted. The perinatal mortality rate was 9.2% (OR 10.1; 95% CI 3.4, 30.1). We then tested selected biochemical markers for prediction of placental abruption. The median of the maternal serum alpha-fetoprotein (MSAFP) multiples of median (MoM) (1.21) was significantly higher in the abruption group (n=57) than in the control group (n=108) (1.07) (p=0.004) at 15-16 gestational weeks. In multivariate analysis, elevated MSAFP remained as an independent risk factor for placental abruption, adjusting for parity ≥ 3, smoking, previous placental abruption, preeclampsia, bleeding in II or III trimester, and placenta previa. MSAFP ≥ 1.5 MoM had a sensitivity of 29% and a false positive rate of 10%. The levels of the maternal serum free beta human chorionic gonadotrophin MoM did not differ between the cases and the controls. None of the angiogenic factors (soluble endoglin, soluble fms-like tyrosine kinase 1, or placental growth factor) showed any difference between the cases (n=42) and the controls (n=50) in the second trimester. The levels of C-reactive protein (CRP) showed no difference between the cases (n=181) and the controls (n=261) (median 2.35 mg/l [interquartile range {IQR} 1.09-5.93] versus 2.28 mg/l [IQR 0.92-5.01], not significant) when tested in the first trimester (mean 10.4 gestational weeks). Chlamydia pneumoniae specific immunoglobulin G (IgG) and immunoglobulin A (IgA) as well as C. trachomatis specific IgG, IgA and chlamydial heat-shock protein 60 antibody rates were similar between the groups. In conclusion, although univariate analysis identified many prepregnancy risk factors for placental abruption, only smoking, uterine malformation, previous cesarean section and history of placental abruption remained significant by multivariate analysis. During the index pregnancy maternal alcohol consumption and smoking and smoking by the partner turned out to be the major independent risk factors for placental abruption. Smoking by both partners multiplied the risk. The liberal use of ultrasound examination contributed little to the management of women with placental abruption. Although second-trimester MSAFP levels were higher in women with subsequent placental abruption, clinical usefulness of this test is limited due to low sensitivity and high false positive rate. Similarly, angiogenic factors in early second trimester, or CRP levels, or chlamydial antibodies in the first trimester failed to predict placental abruption.