804 research outputs found

    State of the art in carbon taxes: a review of the global conclusions

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    Carbon taxes have been advocated as a key economic measure for the reduction of greenhouse gas emissions. The basis of this proposition, is the economic theory that applying a tax on carbon dioxide emissions is the "optimal" solution to addressing the market failure of externalities. In moving from theory to practice, the evidence from comprehensive global assessments, over the last three decades, covering actual policy experience and empirical study of policy effects, requires evolution and refinement of the theory. Carbon taxes are not adopted at the scale, coverage or price level necessary to effectively reduce emissions in line with the Paris Agreement. A persistent "implementation gap" has arisen, largely due to the political and social challenges that accompany taxation. Assessments of policy experience in key sectors of built environment, transport and industry, highlight the critical role of regulation, standards and technology among broader policy programmes. While a carbon tax can provide simplicity and scope, it is not sufficient on its own. Consistent with this finding, recent modelling innovations show that taxes can be employed as part of a portfolio of best practice policies and measures, for deep reduction of emissions. Portfolios can facilitate application of a lower, more "moderate" carbon tax, which enhances the social acceptability and political feasibility of the tax itself. When designing a tax, revenue recycling can help with policy resistance, delivering the "double dividend" of economic and climate gains, and addressing distributional considerations. A carbon tax may be useful to complement the broader portfolio of policies and measures accepted as necessary for long-term transition and transformation. It can offer support and prevent rebounds, but is not a substitute for the fundamental systems change that is at the core of addressing urgent sustainability crises

    Interventions for raising breast cancer awareness in women

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    Background: Breast cancer continues to be the most commonly diagnosed cancer in women globally. Early detection, diagnosis and treatment of breast cancer are key to better outcomes. Since many women will discover a breast cancer symptom themselves, it is important that they are breast cancer aware i.e. have the knowledge, skills and confidence to detect breast changes and present promptly to a healthcare professional.Objectives: To assess the effectiveness of interventions for raising breast cancer awareness in women.Search methods: We searched the Cochrane Breast Cancer Group's Specialised Register (searched 25 January 2016), Cochrane Central Register of Controlled Trials (CENTRAL; 2015, Issue 12) in the Cochrane Library (searched 27 January 2016), MEDLINE OvidSP (2008 to 27 January 2016), Embase (Embase.com, 2008 to 27 January 2016), the World Health Organization’s International Clinical Trials Registry Platform (ICTRP) search portal and ClinicalTrials.gov (searched 27 Feburary 2016). We also searched the reference lists of identified articles and reviews and the grey literature for conference proceedings and published abstracts. No language restriction was applied.Selection criteriaRandomised controlled trials (RCTs) focusing on interventions for raising women’s breast cancer awareness i.e. knowledge of potential breast cancer symptoms/changes and the confidence to look at and feel their breasts, using any means of delivery, i.e. one-to-one/group/mass media campaign(s).Data collection and analysis: Two authors selected studies, independently extracted data and assessed risk of bias. We reported the odds ratio (OR) and 95% confidence intervals (CIs) for dichotomous outcomes and mean difference (MD) and standard deviation (SD) for continuous outcomes. Since it was not possible to combine data from included studies due to their heterogeneity, we present a narrative synthesis. We assessed the quality of evidence using GRADE methods.Main results: We included two RCTs involving 997 women: one RCT (867 women) randomised women to receive either a written booklet and usual care (intervention group 1), a written booklet and usual care plus a verbal interaction with a radiographer or research psychologist (intervention group 2) or usual care (control group); and the second RCT (130 women) randomised women to either an educational programme (three sessions of 60 to 90 minutes) or no intervention (control group).Knowledge of breast cancer symptoms: In the first study, knowledge of non-lump symptoms increased in intervention group 1 compared to the control group at two years postintervention, but not significantly (OR 1.1, 95% CI 0.7 to 1.6; P = 0.66; 449 women; moderate-quality evidence). Similarly, at two years postintervention, knowledge of symptoms increased in the intervention group 2 compared to the control group but not significantly (OR 1.4, 95% CI 0.9 to 2.1; P = 0.11; 434 women; moderate-quality evidence). In the second study, women’s awareness of breast cancer symptoms had increased one month post intervention in the educational group (MD 3.45, SD 5.11; 65 women; low-quality evidence) compared to the control group (MD −0.68, SD 5.93; 65 women; P < 0.001), where there was a decrease in awareness.Knowledge of age-related risk: In the first study, women’s knowledge of age-related risk of breast cancer increased, but not significantly, in intervention group 1 compared to control at two years postintervention (OR 1.8; 95% CI 0.9 to 3.5; P < 0.08; 447 women; moderate-quality evidence). Women's knowledge of risk increased significantly in intervention group 2 compared to control at two years postintervention (OR 4.8, 95% CI 2.6 to 9.0; P < 0.001; 431 women; moderate-quality evidence). In the second study, women’s perceived susceptibility (how at risk they considered themselves) to breast cancer had increased significantly one month post intervention in the educational group (MD 1.31, SD 3.57; 65 women; low-quality evidence) compared to the control group (MD −0.55, SD 3.31; 65 women; P = 0.005), where a decrease in perceived susceptibility was noted.Frequency of Breast Checking: In the first study, no significant change was noted for intervention group 1 compared to control at two years postintervention (OR 1.1, 95% CI 0.8 to 1.6; P = 0.54; 457 women; moderate-quality evidence). Monthly breast checking increased, but not significantly, in intervention group 2 compared to control at two years postintervention (OR 1.3, 95% CI 0.9 to 1.9; P = 0.14; 445 women; moderate-quality evidence). In the second study, women’s breast cancer preventive behaviours increased significantly one month post intervention in the educational group (MD 1.21, SD 2.54; 65 women; low-quality evidence) compared to the control group (MD 0.15, SD 2.94; 65 women; P < 0.045).Breast Cancer Awareness: Women’s overall breast cancer awareness did not change in intervention group 1 compared to control at two years postintervention (OR 1.8, 95% CI 0.6 to 5.30; P = 0.32; 435 women; moderate-quality evidence) while overall awareness increased in the intervention group 2 compared to control at two years postintervention (OR 8.1, 95% CI 2.7 to 25.0; P < 0.001; 420 women; moderate-quality evidence). In the second study, there was a significant increase in scores on the Health Belief Model (that included the constructs of awareness and perceived susceptibility) at one month postintervention in the educational group (mean 1.21, SD 2.54; 65 women) compared to the control group (mean 0.15, SD 2.94; 65 women; P = 0.045).Neither study reported outcomes relating to motivation to check their breasts, confidence to seek help, time from breast symptom discovery to presentation to a healthcare professional, intentions to seek help, quality of life, adverse effects of the interventions, stages of breast cancer, survival estimates or breast cancer mortality rates.Authors' conclusions: Based on the results of two RCTs, a brief intervention has the potential to increase women’s breast cancer awareness. However, findings of this review should be interpreted with caution, as GRADE assessment identified moderate-quality evidence in only one of the two studies reviewed. In addition, the included trials were heterogeneous in terms of the interventions, population studied and outcomes measured. Therefore, current evidence cannot be generalised to the wider context. Further studies including larger samples, validated outcome measures and longitudinal approaches are warranted

    The relationship between tooth size discrepancy and archform classification in orthodontic patients

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    Background: To determine the relationship between clinically significant tooth size discrepancies (TSD) and archform classification in orthodontic patients. Material and Methods: Two hundred and forty consecutive sets of pre-treatment orthodontic study models were scanned and landmarked. All models had permanent teeth erupted from first molar to first molar in both arches. Sixty sets of images were classified into two groups of 30 according to the presence (group 1) or absence (group 2) of a clinically significant overall or anterior TSD (>2 SD from Bolton’s original means). Mean upper and lower archforms were created for each group using a fourth degree polynomial curve. Upper and lower archforms in each group were classified as square, tapering or ovoid; their distribution was analysed using the Fisher test with a 5% level of significance. To evaluate the intra-operator error when determining archform type, the 60 archforms were re-classified by the same operator two weeks later. The unweighted Kappa statistic at 95% confidence intervals was used to determine the similarity of the classification on the two occasions. Results: Reproducibility of the classification of archform was very good (unweighted Kappa statistic of 0.83 with a 95% confidence interval of 0.73, 0.93). There was no statistically significant difference in the distribution of archform type between group 1 and group 2 for the upper ( p =0.3305) or lower ( p =0.6310) arches. Conclusions: The presence of a clinically significant TSD and archform classification do not appear to be related

    Dealing with Time in Health Economic Evaluation: Methodological Issues and Recommendations for Practice

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    Time is an important aspect of health economic evaluation, as the timing and duration of clinical events, healthcare interventions and their consequences all affect estimated costs and effects. These issues should be reflected in the design of health economic models. This article considers three important aspects of time in modelling: (1) which cohorts to simulate and how far into the future to extend the analysis; (2) the simulation of time, including the difference between discrete-time and continuous-time models, cycle lengths, and converting rates and probabilities; and (3) discounting future costs and effects to their present values. We provide a methodological overview of these issues and make recommendations to help inform both the conduct of cost-effectiveness analyses and the interpretation of their results. For choosing which cohorts to simulate and how many, we suggest analysts carefully assess potential reasons for variation in cost effectiveness between cohorts and the feasibility of subgroup-specific recommendations. For the simulation of time, we recommend using short cycles or continuous-time models to avoid biases and the need for half-cycle corrections, and provide advic

    Neuroendocrine Liver Metastases and Orthotopic Liver Transplantation: The US Experience

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    Liver transplantation remains a controversial therapy for Neuroendocrine liver metastases (NLM), with coflicting suvival data reported. The aim was to assess the evolution of outcomes for patients transplanted for NLM in the US, both before and after the introduction of the MELD scoring system in 2002. The UNOS/OPTN database was reviewed to identify patients diagnosed with NLM who subsequently underwent a liver transplantation from 1988 to March 2011 (n = 184); Patient survival was determined using Kaplan-Meier methods and log-rank tests, and cox regression analysis was performed, using SPSS 15.0 (SPSS, Inc, Chicago, IL). The overall NLM patient survivals in the pre-MELD era were 79.5%, 61.4%, and 49.2% at 1, 3, and 5 years, respectively. After the introduction of the MELD score, NET/NLM patients had improved overall patient survivals at 1, 3, and 5 years of 84.7%, 65%, and 57.8%. Patients transplanted after 2002 had an improved survival outcome. Notably, the overall patient survival for NET is not significantly different when compared to the outcomes of patients transplanted for HCC, in the current era. This progress acknowleges the significant improvement in outcomes for NLM patients after liver transplantation and the potential for further gain in the survival of otherwise nonsurgical, terminal patients

    A systematic review of blockchain hardware acceleration architectures

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    The aim of this paper is to provide a systematic literature review of blockchain hardware acceleration. Blockchain technology has achieved significant attention in recent years particularly in the area of cryptocurrency however it is gaining popularity in other applications such as supply chain management and e-government. Based on a structured, systematic review of the relevant literature, we present a classification of the primary areas in blockchain technology that make use of heterogeneous hardware for accelerating certain blockchain functions. Based on these findings, we identify various research gaps and future exploratory directions that are anticipated to be of significant value both for academics and industry practitioners

    The influence of temperature on filtration performance and fouling during cold microfiltration of skim milk

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    Changes in the physicochemical properties and distribution of constituents in skim milk during microfiltration (MF) at low temperature influence filtration performance and product composition. In this study, the influence of processing temperature within the cold MF range (4, 8 and 12 °C) on filtration performance, fouling and partitioning of proteins was investigated. MF at 4 °C required the greatest energy input due to the significantly higher (p < 0.05) viscosity of feed and retentate streams, compared to processing at 8 and 12 °C. The greatest and lowest extents of reversible and irreversible fouling during MF were observed on filtration at 12 and 4 °C, respectively. Chemical analysis of the cleaning solutions post-processing demonstrated that protein was the major foulant; the lowest protein content in the recovered cleaning solutions (50 °C water and 55 °C alkali) was measured after MF at 4 °C. The concentration of β-casein, β-lactoglobulin and ι-lactalbumin in the permeate all decreased throughout MF, due to fouling of the membrane. The greatest decrease in concentration of β-casein in the permeate during MF was observed at 12 °C (18.1%) followed by 8 °C (17.1%) and 4 °C (13.6%). The results of this study provide valuable information on processing efficiency (i.e., energy consumption and protein yield) and membrane fouling during the processing of skim milk in the cold MF range

    Development and validation of colorectal cancer risk prediction tools:A comparison of models

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    Background: Identification of individuals at elevated risk can improve cancer screening programmes by permitting risk-adjusted screening intensities. Previous work introduced a prognostic model using sex, age and two preceding faecal haemoglobin concentrations to predict the risk of colorectal cancer (CRC) in the next screening round. Using data of 3 screening rounds, this model attained an area under the receiver-operating-characteristic curve (AUC) of 0.78 for predicting advanced neoplasia (AN). We validated this existing logistic regression (LR) model and attempted to improve it by applying a more flexible machine-learning approach. Methods: We trained an existing LR and a newly developed random forest (RF) model using updated data from 219,257 third-round participants of the Dutch CRC screening programme until 2018. For both models, we performed two separate out-of-sample validations using 1,137,599 third-round participants after 2018 and 192,793 fourth-round participants from 2020 onwards. We evaluated the AUC and relative risks of the predicted high-risk groups for the outcomes AN and CRC. Results: For third-round participants after 2018, the AUC for predicting AN was 0.77 (95% CI: 0.76–0.77) using LR and 0.77 (95% CI: 0.77–0.77) using RF. For fourth-round participants, the AUCs were 0.73 (95% CI: 0.72–0.74) and 0.73 (95% CI: 0.72–0.74) for the LR and RF models, respectively. For both models, the 5% with the highest predicted risk had a 7-fold risk of AN compared to average, whereas the lowest 80% had a risk below the population average for third-round participants. Conclusion: The LR is a valid risk prediction method in stool-based screening programmes. Although predictive performance declined marginally, the LR model still effectively predicted risk in subsequent screening rounds. An RF did not improve CRC risk prediction compared to an LR, probably due to the limited number of available explanatory variables. The LR remains the preferred prediction tool because of its interpretability.</p

    Influence of pH adjustment on physicochemical properties of microfiltration retentates of skim milk and rehydration properties of resulting powders

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    Effects of pH adjustment on physicochemical properties of microfiltration retentates of skim milk and rehydration of resulting micellar casein concentrate (MCC) powders were investigated. Aliquots of retentate (pH 6.9) were adjusted to pH 7.3, 7.6 or 7.6 followed by readjustment to pH 6.9 (6.9R) prior to powder preparation. The retentates with pH 6.9, 7.3, and 7.6 had casein micelle size of 179, 189 and 197 nm, respectively, while sample 6.9R had size of 183 nm, similar to retentate at pH 6.9. Higher retentate pH resulted in lower ionic calcium and higher conductivity, with sample 6.9R having higher values for both parameters than the pH 6.9 sample. The MCC powders displayed poorer wettability and enhanced dispersibility with increasing retentate pH. Interestingly, the 6.9R powder had the best wettability and dispersibility. This study demonstrated that pH-mediated modifications of the physicochemical properties of retentates improve the rehydration properties of resultant MCC powders
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