194 research outputs found

    Reduction of the size of datasets by using evolutionary feature selection: the case of noise in a modern city

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    Smart city initiatives have emerged to mitigate the negative effects of a very fast growth of urban areas. Most of the population in our cities are exposed to high levels of noise that generate discomfort and different health problems. These issues may be mitigated by applying different smart cities solutions, some of them require high accurate noise information to provide the best quality of serve possible. In this study, we have designed a machine learning approach based on genetic algorithms to analyze noise data captured in the university campus. This method reduces the amount of data required to classify the noise by addressing a feature selection optimization problem. The experimental results have shown that our approach improved the accuracy in 20% (achieving an accuracy of 87% with a reduction of up to 85% on the original dataset).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. This research has been partially funded by the Spanish MINECO and FEDER projects TIN2016-81766-REDT (http://cirti.es), and TIN2017-88213-R (http://6city.lcc.uma.es)

    Low income, community poverty and risk of end stage renal disease

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    BACKGROUND: The risk of end stage renal disease (ESRD) is increased among individuals with low income and in low income communities. However, few studies have examined the relation of both individual and community socioeconomic status (SES) with incident ESRD. METHODS: Among 23,314 U.S. adults in the population-based Reasons for Geographic and Racial Differences in Stroke study, we assessed participant differences across geospatially-linked categories of county poverty [outlier poverty, extremely high poverty, very high poverty, high poverty, neither (reference), high affluence and outlier affluence]. Multivariable Cox proportional hazards models were used to examine associations of annual household income and geospatially-linked county poverty measures with incident ESRD, while accounting for death as a competing event using the Fine and Gray method. RESULTS: There were 158 ESRD cases during follow-up. Incident ESRD rates were 178.8 per 100,000 person-years (105 py) in high poverty outlier counties and were 76.3 /105 py in affluent outlier counties, p trend = 0.06. In unadjusted competing risk models, persons residing in high poverty outlier counties had higher incidence of ESRD (which was not statistically significant) when compared to those persons residing in counties with neither high poverty nor affluence [hazard ratio (HR) 1.54, 95% Confidence Interval (CI) 0.75-3.20]. This association was markedly attenuated following adjustment for socio-demographic factors (age, sex, race, education, and income); HR 0.96, 95% CI 0.46-2.00. However, in the same adjusted model, income was independently associated with risk of ESRD [HR 3.75, 95% CI 1.62-8.64, comparing the < 20,000 income group to the > 75,000 group]. There were no statistically significant associations of county measures of poverty with incident ESRD, and no evidence of effect modification. CONCLUSIONS: In contrast to annual family income, geospatially-linked measures of county poverty have little relation with risk of ESRD. Efforts to mitigate socioeconomic disparities in kidney disease may be best appropriated at the individual level

    SPO11-Independent DNA Repair Foci and Their Role in Meiotic Silencing

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    In mammalian meiotic prophase, the initial steps in repair of SPO11-induced DNA double-strand breaks (DSBs) are required to obtain stable homologous chromosome pairing and synapsis. The X and Y chromosomes pair and synapse only in the short pseudo-autosomal regions. The rest of the chromatin of the sex chromosomes remain unsynapsed, contains persistent meiotic DSBs, and the whole so-called XY body undergoes meiotic sex chromosome inactivation (MSCI). A more general mechanism, named meiotic silencing of unsynapsed chromatin (MSUC), is activated when autosomes fail to synapse. In the absence of SPO11, many chromosomal regions remain unsynapsed, but MSUC takes place only on part of the unsynapsed chromatin. We asked if spontaneous DSBs occur in meiocytes that lack a functional SPO11 protein, and if these might be involved in targeting the MSUC response to part of the unsynapsed chromatin. We generated mice carrying a point mutation that disrupts the predicted catalytic site of SPO11 (Spo11YF/YF), and blocks its DSB-inducing activity. Interestingly, we observed foci of proteins involved in the processing of DNA damage, such as RAD51, DMC1, and RPA, both in Spo11YF/YFand Spo11 knockout meiocytes. These foci preferentially localized to the areas that undergo MSUC and form the so-called pseudo XY body. In SPO11-deficient oocytes, the number

    Comparison of different dosing regimens (once weekly vs. twice weekly, and once weekly vs. once every two weeks) with epoetin delta in patients with chronic kidney disease: a randomized controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Anaemia is a common complication of chronic kidney disease and prevalence increases with declining renal function. Renal anaemia has significant implications for the well-being and quality of life of patients and impacts on morbidity and mortality. Anaemia can be well managed by therapy with erythropoiesis-stimulating agents (ESAs). Previous clinical trials have shown that the only human cell-line-derived ESA, epoetin delta, is well tolerated and effective in maintaining haemoglobin levels in anaemic patients with chronic kidney disease. The half-life of epoetin delta suggests that administration of this agent is feasible once weekly and once every two weeks. We report on the design and rationale of a trial to compare once weekly <it>vs</it>. twice weekly, and once weekly <it>vs</it>. once every two weeks dosing of epoetin delta.</p> <p>Design and methods</p> <p>This is a randomized, open-label, multicentre trial. Patients aged 18 years or above with chronic kidney disease (Stages 3–5) are eligible to enter this trial. Two groups of patients form the trial population, those naïve to ESA therapy and those previously stable on ESA therapy. There are two primary objectives of this trial: 1) to demonstrate non-inferiority between twice weekly and once weekly dosing of epoetin delta in previously naïve patients (assessed by haemoglobin at Week 24); 2) to demonstrate non-inferiority between once weekly and once every two weeks dosing in previously stable patients (assessed by average haemoglobin over Weeks 16–24). Among the secondary analyses will be assessments of haematocrit, number(%) of patients meeting predefined targets for haemoglobin and haematocrit levels, and comparisons of average dose. All patients will receive study medication for 24 weeks and dose will be adjusted according to a predefined algorithm to achieve and maintain haemoglobin ≥ 11 g/dL. All patients completing this trial are eligible to enter a 2-year follow-up study to enable monitoring of emergent adverse events, anti-erythropoietin antibody responses, maintenance of efficacy and changes in diabetic retinopathy status.</p> <p>Discussion</p> <p>To our knowledge, this trial is the first to randomize ESA-naïve patients to different dosing regimens of the same ESA. Data generated will help in guiding the most appropriate dosing frequency for epoetin delta, particularly in those patients new to epoetin delta therapy.</p> <p>Trial registration</p> <p><b>ClinicalTrials.gov: </b>NCT00450333</p

    Early chronic kidney disease: diagnosis, management and models of care

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    Chronic kidney disease (CKD) is prevalent in many countries, and the costs associated with the care of patients with end-stage renal disease (ESRD) are estimated to exceed US$1 trillion globally. The clinical and economic rationale for the design of timely and appropriate health system responses to limit the progression of CKD to ESRD is clear. Clinical care might improve if early-stage CKD with risk of progression to ESRD is differentiated from early-stage CKD that is unlikely to advance. The diagnostic tests that are currently used for CKD exhibit key limitations; therefore, additional research is required to increase awareness of the risk factors for CKD progression. Systems modelling can be used to evaluate the impact of different care models on CKD outcomes and costs. The US Indian Health Service has demonstrated that an integrated, system-wide approach can produce notable benefits on cardiovascular and renal health outcomes. Economic and clinical improvements might, therefore, be possible if CKD is reconceptualized as a part of primary care. This Review discusses which early CKD interventions are appropriate, the optimum time to provide clinical care, and the most suitable model of care to adopt

    Predicting the risk of Chronic Kidney Disease in Men and Women in England and Wales: prospective derivation and external validation of the QKidney® Scores

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    <p>Abstract</p> <p>Background</p> <p>Chronic Kidney Disease is a major cause of morbidity and interventions now exist which can reduce risk. We sought to develop and validate two new risk algorithms (the QKidney<sup>® </sup>Scores) for estimating (a) the individual 5 year risk of moderate-severe CKD and (b) the individual 5 year risk of developing End Stage Kidney Failure in a primary care population.</p> <p>Methods</p> <p>We conducted a prospective open cohort study using data from 368 QResearch<sup>® </sup>general practices to develop the scores. We validated the scores using two separate sets of practices - 188 separate QResearch<sup>® </sup>practices and 364 practices contributing to the THIN database.</p> <p>We studied 775,091 women and 799,658 men aged 35-74 years in the QResearch<sup>® </sup>derivation cohort, who contributed 4,068,643 and 4,121,926 person-years of observation respectively.</p> <p>We had two main outcomes (a) moderate-severe CKD (defined as the first evidence of CKD based on the earliest of any of the following: kidney transplant; kidney dialysis; diagnosis of nephropathy; persistent proteinuria; or glomerular filtration rate of < 45 mL/min) and (b) End Stage Kidney Failure.</p> <p>We derived separate risk equations for men and women. We calculated measures of calibration and discrimination using the two separate validation cohorts.</p> <p>Results</p> <p>Our final model for moderate-severe CKD included: age, ethnicity, deprivation, smoking, BMI, systolic blood pressure, diabetes, rheumatoid arthritis, cardiovascular disease, treated hypertension, congestive cardiac failure; peripheral vascular disease, NSAID use and family history of kidney disease. In addition, it included SLE and kidney stones in women. The final model for End Stage Kidney Failure was similar except it did not include NSAID use.</p> <p>Each risk prediction algorithms performed well across all measures in both validation cohorts. For the THIN cohort, the model to predict moderate-severe CKD explained 56.38% of the total variation in women and 57.49% for men. The D statistic values were high with values of 2.33 for women and 2.38 for men. The ROC statistic was 0.875 for women and 0.876 for men.</p> <p>Conclusions</p> <p>These new algorithms have the potential to identify high risk patients who might benefit from more detailed assessment, closer monitoring or interventions to reduce their risk.</p

    Anemia and chronic kidney disease are associated with poor outcomes in heart failure patients

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    BACKGROUND: Chronic kidney disease (CKD) has been linked to higher heart failure (HF) risk. Anemia is a common consequence of CKD, and recent evidence suggests that anemia is a risk factor for HF. The purpose of this study was to examine among patients with HF, the association between CKD, anemia and inhospital mortality and early readmission. METHODS: We performed a retrospective cohort study in two Swiss university hospitals. Subjects were selected based the presence of ICD-10 HF codes in 1999. We recorded demographic characteristics and risk factors for HF. CKD was defined as a serum creatinine ≥ 124 956;mol/L for women and ≥ 133 μmol/L for men. The main outcome measures were inhospital mortality and thirty-day readmissions. RESULTS: Among 955 eligible patients hospitalized with heart failure, 23.0% had CKD. Twenty percent and 6.1% of individuals with and without CKD, respectively, died at the hospital (p < 0.0001). Overall, after adjustment for other patient factors, creatinine and hemoglobin were associated with an increased risk of death at the hospital, and hemoglobin was related to early readmission. CONCLUSION: Both CKD and anemia are frequent among older patients with heart failure and are predictors of adverse outcomes, independent of other known risk factors for heart failure

    Low documentation of chronic kidney disease among high-risk patients in a managed care population: a retrospective cohort study

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    <p>Abstract</p> <p>Background</p> <p>Early detection of chronic kidney disease (CKD) is sub-optimal among the general population and among high risk patients. The prevalence and impact of major CKD risk factors, diabetes (DM) and hypertension (HTN), on CKD documentation among managed care populations have not been previously reported. We examined this issue in a Kaiser Permanente Georgia (KPG) CKD cohort.</p> <p>Methods</p> <p>KPG enrollees were included in the CKD cohort if they had eGFRs between 60 and 365 days apart that were <90 ml/min during 1999-2006. The current analysis is restricted to participants with eGFR 10-59 ml/min/1.73 m<sup>2</sup>. CKD documentation was defined as a presenting diagnosis of CKD by a primary care physician or nephrologist using ICD-9 event codes. The association between CKD documentation and DM and HTN were assessed with multivariate logistic regression models.</p> <p>Results</p> <p>Of the 50,438 subjects within the overall KPG CKD cohort, 20% (N = 10,266) were eligible for inclusion in the current analysis. Overall, CKD diagnosis documentation was low; only 14.4% of subjects had an event-based CKD diagnosis at baseline. Gender and types 2 diabetes interacted on CKD documentation. The prevalence of CKD documentation increased with the presence of hypertension and/or type 2 diabetes, but type 2 diabetes had a lower effect on CKD documentation. In multivariate analysis, significant predictors of CKD documentation were eGFR, hypertension, type 2 diabetes, congestive heart failure, peripheral artery disease, statin use, age and gender. CKD documentation was lower among women than similarly affected men.</p> <p>Conclusion</p> <p>Among patients with an eGFR 10-59, documentation of CKD diagnosis by primary and subspecialty providers is low within a managed care patient cohort. Gender disparities in CKD documentation observed in the general population were also present among KPG CKD enrollees.</p

    Chronic kidney disease care delivered by US family medicine and internal medicine trainees: results from an online survey

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    BACKGROUND: Complications of chronic kidney disease (CKD) contribute to morbidity and mortality. Consequently, treatment guidelines have been developed to facilitate early detection and treatment. However, given the high prevalence of CKD, many patients with early CKD are seen by non-nephrologists, who need to be aware of CKD complications, screening methods and treatment goals in order to initiate timely therapy and referral. METHODS: We performed a web-based survey to assess perceptions and practice patterns in CKD care among 376 family medicine and internal medicine trainees in the United States. Questions were focused on the identification of CKD risk factors, screening for CKD and associated co-morbidities, as well as management of anemia and secondary hyperparathyroidism in patients with CKD. RESULTS: Our data show that CKD risk factors are not universally recognized, screening for CKD complications is not generally taken into consideration, and that the management of anemia and secondary hyperparathyroidism poses major diagnostic and therapeutic difficulties for trainees. CONCLUSION: Educational efforts are needed to raise awareness of clinical practice guidelines and recommendations for patients with CKD among future practitioners

    Comparative mortality of hemodialysis patients at for-profit and not-for-profit dialysis facilities in the United States, 1998 to 2003: A retrospective analysis

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    <p>Abstract</p> <p>Background</p> <p>Concern lingers that dialysis therapy at for-profit (versus not-for-profit) hemodialysis facilities in the United States may be associated with higher mortality, even though 4 of every 5 contemporary dialysis patients receive therapy in such a setting.</p> <p>Methods</p> <p>Our primary objective was to compare the mortality hazards of patients initiating hemodialysis at for-profit and not-for-profit centers in the United States between 1998 and 2003. For-profit status of dialysis facilities was determined after subjects received 6 months of dialysis therapy, and mean follow-up was 1.7 years.</p> <p>Results</p> <p>Of the study population (<it>N </it>= 205,076), 79.9% were dialyzed in for-profit facilities after 6 months of dialysis therapy. Dialysis at for-profit facilities was associated with higher urea reduction ratios, hemoglobin levels (including levels above 12 and 13 g/dL [120 and 130 g/L]), epoetin doses, and use of intravenous iron, and less use of blood transfusions and lower proportions of patients on the transplant waiting-list (<it>P </it>< 0.05). Patients dialyzed at for-profit and at not-for-profit facilities had similar mortality risks (adjusted hazards ratio 1.02, 95% CI 0.99–1.06, <it>P </it>= 0.143).</p> <p>Conclusion</p> <p>While hemodialysis treatment at for-profit and not-for-profit dialysis facilities is associated with different patterns of clinical benchmark achievement, mortality rates are similar.</p
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