95 research outputs found

    Brain connectivity analysis: a short survey

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    This short survey the reviews recent literature on brain connectivity studies. It encompasses all forms of static and dynamic connectivity whether anatomical, functional, or effective. The last decade has seen an ever increasing number of studies devoted to deduce functional or effective connectivity, mostly from functional neuroimaging experiments. Resting state conditions have become a dominant experimental paradigm, and a number of resting state networks, among them the prominent default mode network, have been identified. Graphical models represent a convenient vehicle to formalize experimental findings and to closely and quantitatively characterize the various networks identified. Underlying these abstract concepts are anatomical networks, the so-called connectome, which can be investigated by functional imaging techniques as well. Future studies have to bridge the gap between anatomical neuronal connections and related functional or effective connectivities

    Automatic ROI Selection in Structural Brain MRI Using SOM 3D Projection

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    This paper presents a method for selecting Regions of Interest (ROI) in brain Magnetic Resonance Imaging (MRI) for diagnostic purposes, using statistical learning and vector quantization techniques. The proposed method models the distribution of GM and WM tissues grouping the voxels belonging to each tissue in ROIs associated to a specific neurological disorder. Tissue distribution of normal and abnormal images is modelled by a Self-Organizing map (SOM), generating a set of representative prototypes, and the receptive field (RF) of each SOM prototype defines a ROI. Moreover, the proposed method computes the relative importance of each ROI by means of its discriminative power. The devised method has been assessed using 818 images from the Alzheimer's disease Neuroimaging Initiative (ADNI) which were previously segmented through Statistical Parametric Mapping (SPM). The proposed algorithm was used over these images to parcel ROIs associated to the Alzheimer's Disease (AD). Additionally, this method can be used to extract a reduced set of discriminative features for classification, since it compresses discriminative information contained in the brain. Voxels marked by ROIs which were computed using the proposed method, yield classification results up to 90% of accuracy for controls (CN) and Alzheimer's disease (AD) patients, and 84% of accuracy for Mild Cognitive Impairment (MCI) and AD patients.This work was partly supported by the MICINN under the TEC2012-34306 project and the Consejería de Innovación, Ciencia y Empresa (Junta de Andalucía, Spain) under the Excellence Projects P09-TIC-4530 and P11-TIC-7103. Data collection and sharing for this project was funded by the Alzheimer's Disease Neuroimaging Initiative (ADNI) (National Institutes of Health Grant U01 AG024904) and DOD ADNI (Department of Defense award number W81XWH-12-2-0012). ADNI is funded by the National Institute on Aging, the National Institute of Biomedical Imaging and Bioengineering, and through generous contributions from the following: Alzheimer's Association; Alzheimer's Drug Discovery Foundation; BioClinica, Inc.; Biogen Idec Inc.; Bristol-Myers Squibb Company; Eisai Inc.; Elan Pharmaceuticals, Inc.; Eli Lilly and Company; F. Hoffmann-La Roche Ltd and its affiliated company Genentech, Inc.; GE Healthcare; Innogenetics, N.V.; IXICO Ltd.; Janssen Alzheimer Immunotherapy Research & Development, LLC.; Johnson & Johnson Pharmaceutical Research & Development LLC.; Medpace, Inc.; Merck & Co., Inc.; Meso Scale Diagnostics, LLC.; NeuroRxResearch; Novartis Pharmaceuticals Corporation; Pfizer Inc.; Piramal Imaging; Servier; Synarc Inc.; and Takeda Pharmaceutical Company. The Canadian Institutes of Health Research is providing funds to support ADNI clinical sites in Canada. Private sector contributions are facilitated by the Foundation for the National Institutes of Health (www.fnih.org). The grantee organization is the Northern California Institute for Research and Education, and the study is coordinated by the Alzheimer's Disease Cooperative Study at the University of California, San Diego. ADNI data are disseminated by the Laboratory for Neuro Imaging at the University of Southern California

    Blood pressure effects of canagliflozin and clinical outcomes in type 2 diabetes and chronic kidney disease: Insights from the CREDENCE trial

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    Background: People with type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD) experience a high burden of hypertension but the magnitude and consistency of blood pressure (BP) lowering with canagliflozin in this population is uncertain. Whether the effects of canagliflozin on kidney and cardiovascular outcomes vary by baseline BP or BP lowering therapy is also unknown. Methods: The CREDENCE trial randomized people with T2DM and CKD to canagliflozin or placebo. Post-hoc, we investigated the effect of canagliflozin on systolic BP across subgroups defined by baseline systolic BP, number of BP lowering drug classes, and history of apparent treatment-resistant hypertension (BP ≥130/80 mmHg while receiving ≥3 classes of BP lowering drugs, including a diuretic). We also assessed whether effects on clinical outcomes differed across these subgroups. Results: The trial included 4,401 participants of whom 3,361 (76.4%) had baseline systolic BP ≥130 mmHg, and 1371 (31.2%) had resistant hypertension. By week 3, canagliflozin reduced systolic BP by 3.50mmHg (95% CI, -4.27 to -2.72), an effect maintained over the duration of the trial, with similar reductions across BP and BP lowering therapy subgroups (all P-interaction ≥0.05). Canagliflozin also reduced the need for initiation of additional BP lowering agents during the trial (HR 0.68, 95% CI 0.61-0.75). The effect of canagliflozin on kidney failure, doubling of serum creatinine, or death due to kidney or cardiovascular disease (HR 0.70, 95% CI 0.59-0.82) was consistent across BP and BP lowering therapy subgroups (all P-interaction ≥0.35), as were effects on other key kidney, cardiovascular and safety outcomes. Conclusions: In people with T2DM and CKD, canagliflozin lowers systolic BP across all BP defined subgroups and reduces the need for additional BP lowering agents. These findings support use of canagliflozin for end-organ protection and as an adjunct BP lowering therapy in people with CKD. Clinical Trial Registration: URL: https://clinicaltrials.gov. Unique Identifier: NCT02065791

    POS-255 EFFECT OF DAPAGLIFLOZIN ON BLOOD PRESSURE IN PATIENTS WITH CKD: A PRE-SPECIFIED ANALYSIS FROM DAPA-CKD

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    Introduction: Hypertension is common in patients with chronic kidney disease (CKD). Sodium-glucose cotransporter 2 inhibitors decrease blood pressure in patients with type 2 diabetes, but the consistency and magnitude of blood pressure lowering with dapagliflozin in patients with CKD is unknown. We performed a pre-specified analysis of the DAPA-CKD trial to investigate the effect of dapagliflozin on systolic blood pressure in patients with CKD, with and without type 2 diabetes. Methods: We randomized 4,304 adults with baseline eGFR 25–75 mL/min/1.73m2and urinary albumin-to-creatinine ratio (UACR) 200–5,000 mg/g to either dapagliflozin 10 mg or placebo once daily; median follow-up was 2.4 years. The primary outcome was a composite of sustained ≥50% eGFR decline, end-stage kidney disease, or death from a kidney or cardiovascular cause. Change in systolic blood pressure was a pre-specified endpoint. Subgroup analyses were performed according to baseline type 2 diabetes status. Results: Baseline mean (SD) systolic blood pressure was 137.1 mmHg (17.4); in participants with and without type 2 diabetes 139.2 mmHg (17.3) and 132.6 mmHg (16.7), respectively. By week 2, dapagliflozin compared to placebo reduced systolic blood pressure by 3.6 mmHg (95%CI 2.8, 4.4; p\u3c0.001), an effect maintained over the duration of the trial, with similar reductions in patients with and without type 2 diabetes (Table). The reduction in systolic blood pressure with dapagliflozin explained 7.6% (95%CI 1.8, 20.9) of the effect on the primary composite outcome, with similar proportions explained in patients with and without type 2 diabetes. Conclusions: In participants with CKD, dapagliflozin lowered systolic blood pressure with a consistent effect in participants with and without type 2 diabetes. The modest reduction in blood pressure explained a small proportion of the benefit of dapagliflozin on the primary outcome. Conflict of interest Potential conflict of interest: HLH received grant funding and honoraria for consultancy as a member of the steering committee of the DAPA-CKD trial from AstraZeneca. Honoraria for steering committee membership paid to his institution from Janssen, Gilead, Bayer, Chinook, CSL Pharma honoraria for consultancy paid to his institution from Abbvie, Boehringer Ingleheim, Retrophin, Novo Nordisk honoraria for advisory board participation paid to his institution from Janssen, Merck, Mitsubishi Tanabe and Munipharma lecture fees received from AstraZeneca and Mitsubishi Tanabe and grant support received from Boehringer Ingelheim

    European ADPKD Forum multidisciplinary position statement on autosomal dominant polycystic kidney disease care

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    Autosomal dominant polycystic kidney disease (ADPKD) is a chronic, progressive condition characterised by the development and growth of cysts in the kidneys and other organs and by additional systemic manifestations. Individuals with ADPKD should have access to life-long, multidisciplinary, specialist and patient-centred care involving: 1) A holistic and comprehensive assessment of the manifestations, complications, prognosis and impact of the disease (in physical, psychological and social terms) on the patient and their family; 2) Access to treatment to relieve symptoms, manage complications, preserve kidney function, lower the risk of cardiovascular disease, and maintain quality of life; 3) Information and support to help patients and their families act as fully informed and active partners in care, i.e. to maintain self-management approaches, deal with the impact of the condition, and participate in decision-making regarding healthcare policies, services and research. Building on discussions at an international Roundtable of specialists and patient advocates involved in ADPKD care, this paper sets out 1) The principles for a patient-centred, holistic approach to the organisation and delivery of ADPKD care in practice, with a focus on multi-specialist collaboration and shared-decision making, 2) The rationale and knowledge base for a Route Map for ADPKD care intended to help patients navigate the services available to them and to help stakeholders and decision-makers take practical steps to ensure that all patients with ADPKD can access the comprehensive multi-specialist care to which they are entitled. Further multispecialty collaboration is encouraged to design and implement these services, and to work with patient organisations to promote awareness building, education, and research

    Real Time QRS Detection Based on M-ary Likelihood Ratio Test on the DFT Coefficients

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    This paper shows an adaptive statistical test for QRS detection of electrocardiography (ECG) signals. The method is based on a M-ary generalized likelihood ratio test (LRT) defined over a multiple observation window in the Fourier domain. The motivations for proposing another detection algorithm based on maximum a posteriori (MAP) estimation are found in the high complexity of the signal model proposed in previous approaches which i) makes them computationally unfeasible or not intended for real time applications such as intensive care monitoring and (ii) in which the parameter selection conditions the overall performance. In this sense, we propose an alternative model based on the independent Gaussian properties of the Discrete Fourier Transform (DFT) coefficients, which allows to define a simplified MAP probability function. In addition, the proposed approach defines an adaptive MAP statistical test in which a global hypothesis is defined on particular hypotheses of the multiple observation window. In this sense, the observation interval is modeled as a discontinuous transmission discrete-time stochastic process avoiding the inclusion of parameters that constraint the morphology of the QRS complexes.This work has received research funding from the Spanish government (www.micinn.es) under project TEC2012 34306 (DiagnoSIS, Diagnosis by means of Statistical Intelligent Systems, 70K€) and projects P09-TIC-4530 (300K€) and P11-TIC-7103 (156K€) from the Andalusian government (http://www.juntadeandalucia.es/organismo​s/economiainnovacioncienciayempleo.html)

    The dapagliflozin and prevention of adverse outcomes in chronic kidney disease (DAPA-CKD) trial: baseline characteristics

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    Background: The Dapagliflozin and Prevention of Adverse outcomes in Chronic Kidney Disease (DAPA-CKD; NCT03036150) trial was designed to assess the effect of the sodium–glucose co-transporter 2 (SGLT2) inhibitor dapagliflozin on kidney and cardiovascular events in participants with CKD with and without type 2 diabetes (T2D). This analysis reports the baseline characteristics of those recruited, comparing them with those enrolled in other trials. Methods: In DAPA-CKD, 4304 participants with a urinary albumin:creatinine ratio (UACR) ≥200 mg/g and estimated glomerular filtration rate (eGFR) between 25 and 75 mL/min/1.73 m2 were randomized to dapagliflozin 10 mg once daily or placebo. Mean eGFR was 43.1 mL/min/1.73 m2 and median UACR was 949 mg/g (108 mg/mmol). Results: Overall, 2906 participants (68%) had a diagnosis of T2D and of these, 396 had CKD ascribed to a cause other than diabetes. The most common causes of CKD after diabetes (n = 2510) were ischaemic/hypertensive nephropathy (n = 687) and chronic glomerulonephritis (n = 695), of which immunoglobulin A nephropathy (n = 270) was the most common. A total of 4174 participants (97%) were receiving an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker, 1882 (43.7%) diuretics, 229 (5.3%) mineralocorticoid receptor antagonists and 122 (2.8%) glucagon-like peptide 1 receptor agonists. In contrast to the Canagliflozin and Renal Events in Diabetes with Established Nephropathy Clinical Evaluation (CREDENCE), the DAPA-CKD trial enrolled participants with CKD due to diabetes and to causes other than diabetes. The mean eGFR of participants in the DAPA-CKD trial was 13.1 mL/min/1.73 m2 lower than in CREDENCE, similar to that in the Finerenone in Reducing Kidney Failure and Disease Progression in DKD (FIDELIO-DKD) trial and the Study Of diabetic Nephropathy with AtRasentan (SONAR). Conclusions: Participants with a wide range of underlying kidney diseases receiving renin–angiotensin system blocking therapy have been enrolled in the DAPA-CKD trial. The trial will examine the efficacy and safety of dapagliflozin in participants with CKD Stages 2–4 and increased albuminuria, with and without T2D

    Social Capital, Network Governance and Social Innovation: Towards a New Paradigm?

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    Limited knowledge and empirical evidence exist so far on how governance is related to social capital, and to comprehensively evaluate the effects of collaborative public-private partnerships in rural development actions, and whether these elements foster socially innovative actions. The book chapter begins to address these knowledge gaps. It highlights the conceptual framework linking social capital and network governance and identifies specific approaches to analysing governance. Moreover, it conceptually identifies the key elements for assessing governance mechanisms in the LEADER approach and explains its adoption in the evaluation method proposed in the book. The chapter concludes by outlining how social capital and governance may support social innovation, a topic which is developed more comprehensively in relation to LEADER's specific contribution in the final chapter of the same book
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