The Effect of Spectral Resolution Upon the Accuracy of Brain Tumor Segmentation from Multi-Spectral MRI Data

Ensemble learning methods are frequently employed for brain tumor segmentation from multi-spectral MRI data. These techniques often require involving several hundreds of computed features for the characterization of the voxels, causing a rise in the necessary storage space by two order of magnitude. Processing such amounts of data also represents a serious computational burden. Under such circumstances it is useful to optimize the feature generation process. This paper proposes to establish the optimal spectral resolution of multispectral MRI data based feature values that allows for the best achievable brain tumor segmentation accuracy without causing unnecessary computational load and storage space waste. Experiments revealed that an 8-bit spectral resolution of the MRI-based feature data is sufficient to obtain the best possible accuracy of ensemble learning methods, while it allows for 50% reduction of the storage space required by the segmentation procedure, compared to the usually deployed featured encoding techniques

Brain Tumor Segmentation from MRI Data Using Ensemble Learning and Multi-Atlas

Atlases are frequently employed to assist medical image segmentation with prior information. This paper introduces a multi-atlas architecture that is trained to locally characterize the appearance (average intensity and standard deviation) of normal tissues in various observed and computed data channels of brain MRI records. The multiple atlas is then deployed to enhance the accuracy of an ensemble learning based brain tumor segmentation procedure that uses binary decision trees. The proposed method is validated using the low-grade tumor volumes of the BraTS 2016 train data set. The use of atlases improve the segmentation quality, causing a rise of up to 1.5% in average Dices scores

Brain Tumor Segmentation from Multi-Spectral MRI Data Using Cascaded Ensemble Learning

Ensemble learning methods are frequently employed in medical decision support. In image segmentation problems the ensemble based decisions require a postprocessing, because the ensemble cannot adequately handle the strong correlation of neighbor voxels. This paper proposes a brain tumor segmentation procedure based on an ensemble cascade. The first ensemble consisting of binary decision trees is trained to separate focal lesions from normal tissues based on four observed and 100 computed features. Starting from the intermediary labels provided by the first ensemble, six local features are computed for each voxel that serve as input for the second ensemble. The second ensemble is a classical random forest that enforces the correlation between neighbor pixels, regularizes the shape of the lesions. The segmentation accuracy is characterized by 85.5% overall Dice Score, 0.5% above previous solutions

Consumption response to aggregate shocks and the role of leverage

This paper investigates the relationship between mortgage leverage and consumption around the 2008 financial crisis. Using data from the UK’s Family Expenditure Survey and Wealth and Asset Survey, we first show that high-leveraged households made larger cuts to consumption following the financial crisis, and this was largely driven by young households. Second, using a life-cycle framework, we investigate the channels by which high-leveraged households may have reduced consumption by more than others. Our key finding is that credit supply tightening is the main driver of the empirical co-movement between pre-crisis leverage and consumption growth after 2008

Poreklo i genetička struktura nekoliko mađarskih divljih i domestifikovanih populacija potočne pastrmke na osnovu PCR-RFLP i mikrosatelitskih markera

U Evropi je, na osnovu studija mitohondrijalne DNK, identifikovano pet evolutivnih linija potočne pastrmke (Salmo trutta m. fario L. 1758): Atlanska, Dunavska, Mediteranska, Jadranska i Mramorna. Mađarske linije bi teorijski trebalo da pripadaju Dunavskoj liniji na osnovu hidrogeografije zemlje, ipak, ovo nije potvrđeno genetičkim studijama. Korišćeni su molekularni markeri da bi se ispitalo genetička pozadina populacije potočne pastrmke u Mađarskoj. Istraživanja su uključila jedini matični nasad potočne pastrmke u Mađarskoj, kao i po jedna populacije u planinskim vencima Bükk, Aggtelek, Börzsöny i Visegrádi, po jedna populacija u svakom. Genetička analiza je do sada sprovedena na 533 individue, isečak peraja je uzorkovan sa svake ribe i PCR-RFLP (kontrolni region mitohondrijalne DNK, laktat dehidrogenaza i somatolaktin geni), kao i analiza mikrosatelitnih markeri (BFRO002, OMM1064, Ssa408uos, SsoSL417, SsoSL438) su bili korišćeni da bi se razlikovale Dunavska i Atlanska linija potočne pastrmke. Na osnovu genetičke analize mitohondrijalne DNK divljih populacija, udeo Dunavskog haplotipa je nizak (< 10 %), sa izuzetkom potoka Apátkúti u planinama Visegrádi, gde je nađena relativno visok udeo Dunavskog haplotipa (34%). 401 analizirani primerak matičnog jata farme je skoro u potpunosti Atlanski haplotip, što ukazuje na efekat osnivača. Iako su kasnije prikupljeni primerci iz obližnjeg potoka i pridodati matičnom jatu, njihov broj je bio ograničen jer su uglavnom svi bili mužjaci. Budući da je jedino matično jato u Mađarskoj, ribe sa ove farme se koriste za poribljavanje od strane ribolovaca, što može dovesti do značajnog uticaja na prirodne populacije. Na osnovu analize nuklearnih markera sve populacije su veoma heterogene. Veliki udeo (60-80%) Atlanskih alela primećen za ove markere na svim lokacijama gde je obavljano uzorkovanje ukazuje na efekat intenzivnog poribljavanja mađarskih salmonidnih regiona. Analize mikrosatelitskih markera su ukazale na visoku heterozigotnost i Hardy-Weinberg-ovu ravnotežu svih populacija

Az ökológiai gazdálkodás hazai helyzete - Trendek és kitörési pontok |Program|Összefoglalók|Résztvevők|

A kiadvány az ÖMKi 2012. február 2-án megrendezett első szakmai konferenciájának programját és előadásainak anyagát tartalmazza. Az ökológiai gazdálkodás hazai helyzete - Trendek és kitörési pontok c. rendezvényt minden várakozást felülmúló érdeklődés övezte, több mint 400-an regisztráltak. A rendezvény fővédnöke Fazekas Sándor vidékfejlesztési miniszter volt, aki megnyitó beszédében elmondta: „Háromszázezer hektárra szeretnénk növelni hazánkban a biogazdálkodás alá vont területek nagyságát 2020-ig, ezért a tárca ökológiai mezőgazdálkodási programot dolgoz ki. Kiemelten támogatjuk a biogazdálkodókat, segítséget nyújtunk az átálláshoz”. A konferencián jelen voltak az ágazat legfontosabb szervezeteinek képviselői, úgy a gazdák, a civil társadalom, mint a közigazgatás és a tudomány világából. Értékes párbeszéd alakult ki a résztvevők között, és lehetőség nyílt a vélemények ütköztetésére is, amit szervezőként kifejezetten hasznosnak tartunk, hiszen hozzátartozik az átlátható, demokratikus biomozgalom megteremtéséhez

Interplay of Structural Disorder and Short Binding Elements in the Cellular Chaperone Function of Plant Dehydrin ERD14.

Details of the functional mechanisms of intrinsically disordered proteins (IDPs) in living cells is an area not frequently investigated. Here, we dissect the molecular mechanism of action of an IDP in cells by detailed structural analyses based on an in-cell nuclear magnetic resonance experiment. We show that the ID stress protein (IDSP) A. thaliana Early Response to Dehydration (ERD14) is capable of protecting E. coli cells under heat stress. The overexpression of ERD14 increases the viability of E. coli cells from 38.9% to 73.9% following heat stress (50 °C × 15 min). We also provide evidence that the protection is mainly achieved by protecting the proteome of the cells. In-cell NMR experiments performed in E. coli cells show that the protective activity is associated with a largely disordered structural state with conserved, short sequence motifs (K- and H-segments), which transiently sample helical conformations in vitro and engage in partner binding in vivo. Other regions of the protein, such as its S segment and its regions linking and flanking the binding motifs, remain unbound and disordered in the cell. Our data suggest that the cellular function of ERD14 is compatible with its residual structural disorder in vivo

Genetic and environmental factors on heart rate, mean arterial pressure and carotid intima–media thickness: A longitudinal twin study

Background: Heart rate (HR), mean arterial pressure (MAP) and carotid intima–media thickness (cIMT) are moderately heritable cardiovascular traits, but the environmental effects on the longitudinal change of their heritability have never been investigated. Methods: 368 Italian and Hungarian twins (107 monozygotic, 77 dizygotic) underwent oscillometric measurement and B-mode sonography of bilateral carotid arteries in 2009/2010 and 2014. Within- -individual/cross-study wave, cross-twin/within-study wave and cross-twin/cross-study wave correlations were estimated, and bivariate Cholesky models were fitted to decompose the total variance at each wave and covariance between study waves into additive genetic, shared and unique environmental components. Results: For each trait, a moderate longitudinal stability was observed, with within-individual/crosswave correlations of 0.42 (95% CI: 0.33–0.51) for HR, 0.34 (95% CI: 0.24–0.43) for MAP, and 0.23 (95% CI: 0.12–0.33) for cIMT. Cross-twin/cross-wave correlations in monozygotic pairs were all significant and substantially higher than the corresponding dizygotic correlations. Genetic continuity was the main source of longitudinal stability, with across-time genetic correlations of 0.52 (95% CI: 0.29–0.71) for HR, 0.56 (95% CI: 0.31–0.81) for MAP, and 0.36 (95% CI: 0.07–0.64) for cIMT. Overlapping genetic factors explained respectively 57%, 77%, and 68% of the longitudinal covariance of the HR, MAP and cIMT traits. Conclusions: Genetic factors have a substantial role in the longitudinal change of HR, MAP and cIMT; however, the influence of unique environmental factors remains relevant. Further studies should better elucidate whether epigenetic mechanisms have a role in influencing the stability of the investigated traits over time

Stakeholders' perspectives on the operationalisation of the ecosystem service concept : Results from 27 case studies

The ecosystem service (ES) concept is becoming mainstream in policy and planning, but operational influence on practice is seldom reported. Here, we report the practitioners' perspectives on the practical implementation of the ES concept in 27 case studies. A standardised anonymous survey (n = 246), was used, focusing on the science-practice interaction process, perceived impact and expected use of the case study assessments. Operationalisation of the concept was shown to achieve a gradual change in practices: 13% of the case studies reported a change in action (e.g. management or policy change), and a further 40% anticipated that a change would result from the work. To a large extent the impact was attributed to a well conducted science-practice interaction process (>70%). The main reported advantages of the concept included: increased concept awareness and communication; enhanced participation and collaboration; production of comprehensive science-based knowledge; and production of spatially referenced knowledge for input to planning (91% indicated they had acquired new knowledge). The limitations were mostly case-specific and centred on methodology, data, and challenges with result implementation. The survey highlighted the crucial role of communication, participation and collaboration across different stakeholders, to implement the ES concept and enhance the democratisation of nature and landscape planning. (C) 2017 Published by Elsevier B.V.Peer reviewe