16 resultados para Risk sources
Resumo:
Lead (Pb) is a non-threshold toxin capable of inducing toxic effects at any blood level but availability of soil screening criteria for assessing potential health risks is limited. The oral bioaccessibility of Pb in 163 soil samples was attributed to sources through solubility estimation and domain identification. Samples were extracted following the Unified BARGE Method. Urban, mineralisation, peat and granite domains accounted for elevated Pb concentrations compared to rural samples. High Pb solubility explained moderate-high gastric (G) bioaccessible fractions throughout the study area. Higher maximum G concentrations were measured in urban (97.6 mg kg−1) and mineralisation (199.8 mg kg−1) domains. Higher average G concentrations occurred in mineralisation (36.4 mg kg−1) and granite (36.0 mg kg−1) domains. Findings suggest diffuse anthropogenic and widespread geogenic contamination could be capable of presenting health risks, having implications for land management decisions in jurisdictions where guidance advises these forms of pollution should not be regarded as contaminated land.
Resumo:
Digital dermatitis (DD) is a bacterial disease that primarily affects the skin on the heels of cattle. It is a major cause of lameness in dairy cows and a significant problem for the dairy industry in many countries, causing reduced animal welfare and economic loss. A wide range of infection levels has been found on infected farms, prompting investigations into both farm level and animal level risk factors for DD occurrence. There also appears to be individual variation between animals in susceptibility to the disease. The identification of factors affecting individual variation in susceptibility to DD might allow changes in breeding policies or herd management which could be used to reduce DD prevalence. Factors mentioned in the literature as possibly influencing individual variation in susceptibility to DD include physical factors such as hoof conformation and properties of the skin, physiological factors such as the efficacy of the immune response, and behavioural factors such as standing half in cubicles. Further work is required to determine the influence of these factors, identify the genetic basis of variation, clarify the level of heritability of DD susceptibility and to determine how this is correlated with production and health traits currently used in breeding programmes.
Resumo:
Objective: To assess the role of plasma total homocysteine (tHcy) concentrations and homozygosity for the thermolabile variant of the methylenetetrahydrofolate reductase (MTHFR) C677T gene as risk factors for retinal vascular occlusive disease.
Design: Retinal vein occlusion (RVO) is an important cause of vision loss. Early meta-analyses showed that tHcy was associated with an increased risk of RVO, but a significant number of new studies have been published. Participants and/or Controls: RVO patients and controls.
Methods: Data sources included MEDLINE, Web of Science, and PubMed searches and searching reference lists of relevant articles and reviews. Reviewers searched the databases, selected the studies, and then extracted data. Results were pooled quantitatively using meta-analytic methods.
Main Outcome Measures: tHcy concentrations and MTHFR genotype.
Results: There were 25 case-control studies for tHcy (1533 cases and 1708 controls) and 18 case-control studies for MTHFR (1082 cases and 4706 controls). The mean tHcy was on average 2.8 mol/L (95% confidence
interval [CI], 1.8 –3.7) greater in the RVO cases compared with controls, but there was evidence of between-study heterogeneity (P0.001, I2 93%). There was funnel plot asymmetry suggesting publication bias. There was no evidence of association between homozygosity for the MTHFR C677T genotype and RVO (odds ratio [OR] 1.20; 95% CI, 0.84–1.71), but again marked heterogeneity (P 0.004, I2 53%) was observed.
Conclusions: There was some evidence that elevated tHcy was associated with RVO, but not homozygosity for the MTHFR C677T genotype. Both analyses should be interpreted cautiously because of marked heterogeneity between the study estimates and possible effect of publication bias on the tHcy findings.
Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.
Resumo:
Since 1994, Irish cattle have been exposed to greater risks of acquiring Mycobacterium avium subspecies paratuberculosis (MAP) infection as a consequence of the importation of over 70,000 animals from continental Europe. In recent years, there has been an increase in the number of reported clinical cases of paratuberculosis in Ireland. This study examines the prevalence of factors that promote the introduction and within-herd transmission of Mycobacterium avium subspecies paratuberculosis (MAP) on selected Irish dairy farms in the Cork region, and the association between these factors and the results of MAP screening tests on milk sock filter residue (MFR). A total of 59 dairy farms, selected using non-random methods but apparently free of endemic paratuberculosis, were enrolled into the study. A questionnaire was used to collect data about risk factors for MAP introduction and transmission. The MFR was assessed on six occasions over 24 months for the presence of MAP, using culture and immunomagnetic separation prior to polymerase chain reaction (IMS-PCR). Furthermore, blood samples from all entire male and female animals over one year of age in 20 herds were tested by ELISA. Eighteen (31%) farms had operated as closed herds since 1994, 28 (47%) had purchased from multiple sources and 14 (24%) had either direct or indirect (progeny) contact with imported animals. Milk and colostrum were mixed on 51% of farms, while 88% of farms fed pooled milk. Thirty (51%) herds tested negative to MFR culture and IMS-PCR, 12 (20%) were MFR culture positive, 26 (44%) were IMS-PCR positive and seven (12%) were both culture and IMS-PCR positive. The probability of a positive MFR culture was significantly associated with reduced attendance at calving, and with increased use of individual calf pens and increased (but not significantly) if multiple suckling was practised. There was poor agreement between MFR culture and MFR IMS-PCR results, but moderate agreement between MFR culture and ELISA test results. This study highlights a lack of awareness among Irish dairy farmers about the effect of inadequate biosecurity on MAP introduction. Furthermore, within-herd transmission will be facilitated by traditional calf rearing and waste management practices. The findings of viable MAP in the presence of known transmission factors in non-clinically affected herds could be a prelude to long-term problems for the Irish cattle and agri-business generally.
Resumo:
Changes to software requirements occur during initial development and subsequent to delivery, posing a risk to cost and quality while at the same time providing an opportunity to add value. Provision of a generic change source taxonomy will support requirements change risk visibility, and also facilitate richer recording of both pre- and post-delivery change data. In this paper we present a collaborative study to investigate and classify sources of requirements change, drawing comparison between those pertaining to software development and maintenance. We begin by combining evolution, maintenance and software lifecycle research to derive a definition of software maintenance, which provides the foundation for empirical context and comparison. Previously published change ‘causes’ pertaining to development are elicited from the literature, consolidated using expert knowledge and classified using card sorting. A second study incorporating causes of requirements change during software maintenance results in a taxonomy which accounts for the entire evolutionary progress of applications software. We conclude that the distinction between the terms maintenance and development is imprecise, and that changes to requirements in both scenarios arise due to a combination of factors contributing to requirements uncertainty and events that trigger change. The change trigger taxonomy constructs were initially validated using a small set of requirements change data, and deemed sufficient and practical as a means to collect common requirements change statistics across multiple projects.
Resumo:
The nuclear accident in Chernobyl in 1986 is a dramatic example of the type of incidents that are characteristic of a risk society. The consequences of the incident are indeterminate, the causes complex and future developments unpredictable. Nothing can compensate for its effects and it affects a broad population indiscriminately. This paper examines the lived experience of those who experienced biographical disruption as residents of the region on the basis of qualitative case studies carried out in 2003 in the Chernobyl regions of Russia, Ukraine and Belarus. Our analysis indicates that informants tend to view their future as highly uncertain and unpredictable; they experience uncertainty about whether they are already contaminated, and they have to take hazardous decisions about where to go and what to eat. Fear, rumours and experts compete in supplying information to residents about the actual and potential consequences of the disaster, but there is little trust in, and only limited awareness of, the information that is provided. Most informants continue with their lives and do what they must or even what they like, even where the risks are known. They often describe their behaviour as being due to economic circumstances; where there is extreme poverty, even hazardous food sources are better than none. Unlike previous studies, we identify a pronounced tendency among informants not to separate the problems associated with the disaster from the hardships that have resulted from the break-up of the USSR, with both events creating a deep-seated sense of resignation and fatalism. Although most informants hold their governments to blame for lack of information, support and preventive measures, there is little or no collective action to have these put in place. This contrasts with previous research which has suggested that populations affected by disasters attribute crucial significance to that incident and, as a consequence, become increasingly politicized with regard to related policy agendas.
Resumo:
The aim of our study was to investigate whether dietary fat and meat intakes are associated with reflux esophagitis (RE), Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC). In this all-Ireland case-control study, dietary intake data were collected using a food frequency questionnaire in 219 RE patients, 220 BE patients, 224 EAC patients and 256 frequency-matched controls between 2002 and 2005. Unconditional multiple logistic regression analysis was used to examine the association between dietary variables and disease risk using quartiles of intake, to attain odds ratios (ORs) and 95% confidence intervals (95% CIs), while adjusting for potential confounders. Patients in the highest quartile of total fat intake had a higher risk of RE (OR = 3.54; 95% CI = 1.32-9.46) and EAC (OR = 5.44; 95% CI = 2.08-14.27). A higher risk of RE and EAC was also reported for patients in the highest quartile of saturated fat intake (OR = 2.79; 95% CI = 1.11-7.04; OR = 2.41; 95% CI = 1.14-5.08, respectively) and monounsaturated fat intake (OR = 2.63; 95% CI = 1.01-6.86; OR = 5.35; 95% CI = 2.14-13.34, respectively). Patients in the highest quartile of fresh red meat intake had a higher risk of EAC (OR = 3.15; 95% CI = 1.38-7.20). Patients in the highest category of processed meat intake had a higher risk of RE (OR = 4.67; 95% CI = 1.71-12.74). No consistent associations were seen for BE with either fat or meat intakes. Further studies investigating the association between dietary fat and food sources of fat are needed to confirm these results.
Resumo:
Dioxin contamination of the food chain typically occurs when cocktails of combustion residues or polychlorinated biphenyl (PCB) containing oils become incorporated into animal feed. These highly toxic compounds are bioaccumulative with small amounts posing a major health risk. The ability to identify animal exposure to these compounds prior to their entry into the food chain may be an invaluable tool to safeguard public health. Dioxin-like compounds act by a common mode of action and this suggests that markers or patterns of response may facilitate identification of exposed animals. However, secondary co-contaminating compounds present in typical dioxin sources may affect responses to compounds. This study has investigated for the first time the potential of a metabolomics platform to distinguish between animals exposed to different sources of dioxin contamination through their diet. Sprague-Dawley rats were given feed containing dioxin-like toxins from hospital incinerator soot, a common PCB oil standard and pure 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (normalized at 0.1 µg/kg TEQ) and acquired plasma was subsequently biochemically profiled using ultra high performance liquid chromatography (UPLC) quadropole time-of-flight-mass spectrometry (QTof-MS). An OPLS-DA model was generated from acquired metabolite fingerprints and validated which allowed classification of plasma from individual animals into the four dietary exposure study groups with a level of accuracy of 97-100%. A set of 24 ions of importance to the prediction model, and which had levels significantly altered between feeding groups, were positively identified as deriving from eight identifiable metabolites including lysophosphatidylcholine (16:0) and tyrosine. This study demonstrates the enormous potential of metabolomic-based profiling to provide a powerful and reliable tool for the detection of dioxin exposure in food-producing animals.
Resumo:
Hyperglycemia plays a pivotal role in the development and progression of vascular complications, which are the major sources of morbidity and mortality in diabetes. Furthermore, these vascular complications often persist and progress despite improved glucose control, possibly as a result of prior episodes of hyperglycemia. Epigenetic modifications mediated by histone methyltransferases are associated with gene-activating events that promote enhanced expression of key proinflammatory molecules implicated in vascular injury. In this study, we investigated genetic polymorphisms of the SETD7, SUV39H1, and SUV39H2 methyltransferases as predictors of risk for micro- and macrovascular complications in type 1 diabetes.
Resumo:
The aim of this paper is to analyse vulnerability and robustness of small and medium size enterprises (SMEs) supply chains and to consider contextual factors that might influence the success of their disturbance management: Risky product and business environment. By using an exploratory case study it is shown how these contextual factors attribute vulnerability sources, contribute to the robustness of a company’s performance and supply chain vulnerability, as well as how a company seeks to manage internal and external vulnerability sources. The exploratory case is based on a fresh food supply chain of a manufacturing SME operating in a developing market.
Case findings suggest that fresh food supply chains of a manufacturing SME in developing markets are prone to disruptions of their logistics and production processes due to ‘riskiness’ of fresh food products, the ‘riskiness’ of developing markets, as well as ‘riskiness’ of SMEs themselves. However, this does not necessarily indicate the vulnerability of an SME and its entire supply chain. Findings indicate that SMEs can be very successful in disturbance management by selective use of redesign strategies that aim to prevent or reduce the impact of disturbances. More precise, it is likely that an SME can achieve robust performance by employing preventive redesign strategies in managing disturbances that result from internal, company related vulnerability sources, while impact reduction strategies are likely to contribute to robust performance of an SME if used to manage disturbances that result from internal, supply chain related vulnerability sources, as well as external vulnerability sources.
Resumo:
BACKGROUND: Assessing methodological quality of primary studies is an essential component of systematic reviews. Following a systematic review which used a domain based system [United States Preventative Services Task Force (USPSTF)] to assess methodological quality, a commonly used numerical rating scale (Downs and Black) was also used to evaluate the included studies and comparisons were made between quality ratings assigned using the two different methods. Both tools were used to assess the 20 randomized and quasi-randomized controlled trials examining an exercise intervention for chronic musculoskeletal pain which were included in the review. Inter-rater reliability and levels of agreement were determined using intraclass correlation coefficients (ICC). Influence of quality on pooled effect size was examined by calculating the between group standardized mean difference (SMD).
RESULTS: Inter-rater reliability indicated at least substantial levels of agreement for the USPSTF system (ICC 0.85; 95% CI 0.66, 0.94) and Downs and Black scale (ICC 0.94; 95% CI 0.84, 0.97). Overall level of agreement between tools (ICC 0.80; 95% CI 0.57, 0.92) was also good. However, the USPSTF system identified a number of studies (n = 3/20) as "poor" due to potential risks of bias. Analysis revealed substantially greater pooled effect sizes in these studies (SMD -2.51; 95% CI -4.21, -0.82) compared to those rated as "fair" (SMD -0.45; 95% CI -0.65, -0.25) or "good" (SMD -0.38; 95% CI -0.69, -0.08).
CONCLUSIONS: In this example, use of a numerical rating scale failed to identify studies at increased risk of bias, and could have potentially led to imprecise estimates of treatment effect. Although based on a small number of included studies within an existing systematic review, we found the domain based system provided a more structured framework by which qualitative decisions concerning overall quality could be made, and was useful for detecting potential sources of bias in the available evidence.
Resumo:
In recent years much attention has been given to systemic risk and maintaining financial stability. Much of the focus, rightly, has been on market failures and the role of regulation in addressing them. This article looks at the role of domestic policies and government actions as sources of global instability. The global financial system is built upon global markets controlled by national financial and macroeconomic policies. In this context, regulatory asymmetries, diverging policy preferences, and government failures add a further dimension to global systemic risk not present at the national level.
Systemic risk is a result of the interplay between two independent variables: an underlying trigger event, in this analysis a domestic policy measure, and a transmission channel. The solution to systemic risk requires tackling one of these variables. In a domestic setting, the centralization of regulatory power into one single authority makes it easier to balance the delicate equilibrium between enhancing efficiency and reducing instability. However, in a global financial system in which national financial policies serve to maximize economic welfare, regulators will be confronted with difficult policy and legal tradeoffs.
We investigate the role that financial regulation plays in addressing domestic policy failures and in controlling the danger of global financial interdependence. To do so we analyse global financial interconnectedness, and explain its role in transmitting instability; we investigate the political economy dynamics at the origin of regulatory asymmetries and government failures; and we discuss the limits of regulation.
Resumo:
INTRODUCTION: A disaster is a serious disruption to the functioning of a community that exceeds its capacity to cope within its own resources. Risk communication in disasters aims to prevent and mitigate harm from disasters, prepare the population before a disaster, disseminate information during disasters and aid subsequent recovery. The aim of this systematic review is to identify, appraise and synthesise the findings of studies of the effects of risk communication interventions during four stages of the disaster cycle.
METHODS: We searched the Cochrane Central Register of Controlled Trials, Embase, MEDLINE, PsycInfo, Sociological Abstracts, Web of Science and grey literature sources for randomised trials, cluster randomised trials, controlled and uncontrolled before and after studies, interrupted time series studies and qualitative studies of any method of disaster risk communication to at-risk populations. Outcome criteria were disaster-related knowledge and behaviour, and health outcomes.
RESULTS: Searches yielded 5,224 unique articles, of which 100 were judged to be potentially relevant. Twenty-five studies met the inclusion criteria, and two additional studies were identified from other searching. The studies evaluated interventions in all four stages of the disaster cycle, included a variety of man-made, natural and infectious disease disasters, and were conducted in many disparate settings. Only one randomised trial and one cluster randomised trial were identified, with less robust designs used in the other studies. Several studies reported improvements in disaster-related knowledge and behaviour.
DISCUSSION: We identified and appraised intervention studies of disaster risk communication and present an overview of the contemporary literature. Most studies used non-randomised designs that make interpretation challenging. We do not make specific recommendations for practice but highlight the need for high-quality randomised trials and appropriately-analysed cluster randomised trials in the field of disaster risk communication where these can be conducted within an appropriate research ethics framework.
Resumo:
Objective: To conduct a systematic review of risk factors associated with the development of Endometrial Hyperplasia (EH).
Data sources: Ovid MEDLINE, EMBASE and Web of Science databases were searched from inception to 30 June 2015.
Study eligibility: Fifteen observational studies that reported on EH risk in relation to lifestyle factors (n=14), medical history (n=11), reproductive and menstrual history (n=9) and measures of socio-economic status (n=2) were identified. Pooled relative risk estimates and corresponding 95% confidence intervals (CI) were able to be derived for EH and Body Mass Index (BMI), smoking, diabetes and hypertension, using random effects models comparing high versus low categories.
Results: The pooled relative risk for EH when comparing women with the highest versus lowest BMI was 1.82 (95% CI 1.22–2.71; n=7 studies, I2=90.4%). No significant associations were observed for EH risk for smokers compared with non-smokers (RR 0.88, 95% CI 0.66-1.17; n=3, I2=0.0%), hypertensive versus normotensive women (RR 1.51, 95% CI 0.72–3.15; n=5 studies, I2=79.1%), or diabetic versus non-diabetic women (RR 1.77, 95% CI 0.79–3.96; n=5 studies, I2=31.8%) respectively although the number of included studies was limited. There were mixed reports on the relationship between age and risk of EH. Too few studies reported on other factors to reach any conclusions in relation to EH risk.
Conclusions: A high BMI was associated with an increased risk of EH, providing additional rationale for women to maintain a normal body weight. No significant associations were detected for other factors and EH risk, however relatively few studies have been conducted and few of the available studies adequately adjusted for relevant confounders. Therefore, further aetiological studies of endometrial hyperplasia are warranted.