322 research outputs found
Simultaneous interval regression for K-nearest neighbor
International audienceIn some regression problems, it may be more reasonable to predict intervals rather than precise values. We are interested in finding intervals which simultaneously for all input instances x ∈X contain a β proportion of the response values. We name this problem simultaneous interval regression. This is similar to simultaneous tolerance intervals for regression with a high confidence level γ ≈ 1 and several authors have already treated this problem for linear regression. Such intervals could be seen as a form of confidence envelop for the prediction variable given any value of predictor variables in their domain. Tolerance intervals and simultaneous tolerance intervals have not yet been treated for the K-nearest neighbor (KNN) regression method. The goal of this paper is to consider the simultaneous interval regression problem for KNN and this is done without the homoscedasticity assumption. In this scope, we propose a new interval regression method based on KNN which takes advantage of tolerance intervals in order to choose, for each instance, the value of the hyper-parameter K which will be a good trade-off between the precision and the uncertainty due to the limited sample size of the neighborhood around each instance. In the experiment part, our proposed interval construction method is compared with a more conventional interval approximation method on six benchmark regression data sets
Псориаз: клинико-эпидемиологические особенности и вопросы терапии
Aim. This study sets out to establish the demographic and clinical features of psoriasis and its co-morbidities; to describe approaches to treating patients in Russia, to whom the systemic therapy of drugs has been recommended; to assess the effects of this dermatosis on the patients' quality of life and work productivity; to assess the degree of consistency between dermatologists' and patients' estimates concerning the severity of the disease, complaints/objective manifestations and treatment satisfaction.Methods. Data from the GfK Disease Atlas was used. This ATLAS was filed within a global programme Growth from Knowledge that collected reliable data in the context of everyday clinical practice in 9 countries. The paper presents the results solely for the Russian sample. The study involved patients with moderate or severe psoriasis who were receiving systemic therapy for this disease. Using specially developed forms, ATLAS specialists registered data about patients, their disease and received treatment. The patients affected by psoriasis, who participated in the study, were questioned about their disease. Dermatologists assessed the severity of psoriasis, the patients' complaints, co-morbidities and received treatment. The patients completed questionnaires aimed at assessing the quality of their life [Dermatology Life Quality Index, DLQI] and their work productivity [Work Productivity and Activity Impairment, WPAI]. The concordance between the patients' and the dermatologists' estimates was assessed using Cohen's kappa coefficient.Results. Overall, 3,821 patients participated in the ATLAS programme, out of whom 300 patients were Russians. The average time since psoriasis diagnosis amounted to 9.9 years. 51 % of the patients complained about itching in the lesion areas. Psoriatic arthritis was registered in 19 % of the cases. Among co-morbidities, anxiety or depression was most often recorded (11 %, respectively). The proportion of patients with pruritus and related comorbid conditions increased with psoriasis severity. The disease negatively affected the quality of patients’ life (the average value of DLQI was 7.1) and their work productivity (a decrease in the work productivity reached 33.2 %), with these indicators deteriorating with psoriasis severity. Despite the dominance of moderate and severe psoriasis forms among the participants, 60 % of the patients received therapy only with topical medications. The concordance rate between the patients and the dermatologists concerning the estimation of psoriasis severity and treatment satisfaction was low.Conclusion. Despite the therapy with systemic drugs, the patients' quality of life affected by severe or moderate psoriasis forms remained low. The consistency between the views on the treatment success between the patients and the dermatologists was low.Цель: Установить демографические и клинические характеристики псориаза, коморбидных ему состояний и подходы к лечению российских пациентов, которым была показана терапия системными препаратами; оценить влияние данного дерматоза на качество жизни и работоспособность пациентов, а также оценить степень согласованности оценок о тяжести заболевания, жалоб/объективных проявлений и удовлетворенности лечением псориаза между пациентами и дерматологами.Методы. Использовались данные, полученные в Глобальной программе сбора доказательных данных в условиях повседневной клинической практики Growth from Knowledge (GfK) Disease ATLAS, проводившейся в девяти странах. В работе представлены результаты только по российской выборке. В исследовании участвовали пациенты со среднетяжелым или тяжелым псориазом, которые получали системную терапию по поводу данного заболевания. В рамках наблюдательной программы ATLAS специалисты регистрировали данные о пациентах, их заболевании и проводимом лечении в специально разработанных формах. Больные псориазом, участвовавшие в исследовании, самостоятельно отвечали на вопросы о своем заболевании. Дерматологами оценивались тяжесть псориаза, имеющиеся жалобы, коморбидности и проводимое лечение, в то время как пациенты заполняли опросники по оценке качества жизни и работоспособности (дерматологический индекс качества жизни [Dermatology Life Quality Index, DLQI] и опросник производительности труда и повседневной активности [Work Productivity and Activity Impairment, WPAI] соответственно). Конкордантность оценок пациентов и дерматологов оценивалась по каппа-коэффициенту Коэна.Результаты: Всего в программе ATLAS в мире участвовали 3821 пациент, из которых 300 были российскими. Среднее время с момента постановки диагноза псориаза составило 9,9 года. 51 % пациентов предъявляли жалобы на зуд в очагах поражения. Псориатический артрит зарегистрирован в 19 % случаев. Среди коморбидностей наиболее часто регистрировали тревожность либо депрессия (11 % соответственно). Доля пациентов с зудом и сопутствующими коморбидными состояниями увеличивалась по мере нарастания тяжести псориаза. Заболевание отрицательно сказывалось на качестве жизни пациентов (среднее значение DLQI 7,1) и работоспособности (снижение работоспособности составило 33,2 %), причем данные показатели ухудшались по мере нарастания тяжести заболевания. Несмотря на доминирование среднетяжелых и тяжелых форм псориаза у участников исследования, 60 % пациентов получали только терапию топическими лекарственными средствами. Установленная степень конкордантности между пациентами и дерматологами по оценке тяжести псориаза и общей удовлетворенности достигнутыми результатами проводимой терапии была низкой.Вывод. Несмотря на проводимую терапию системными препаратами, качество жизни пациентов с тяжелым и среднетяжелым псориазом оставалась сниженной. Согласованность представлений об успешности результатов лечения данного дерматоза между пациентами и дерматологами была низкой
LD Hub:a centralized database and web interface to perform LD score regression that maximizes the potential of summary level GWAS data for SNP heritability and genetic correlation analysis
Motivation: LD score regression is a reliable and efficient method of using genome-wide association study (GWAS) summary-level results data to estimate the SNP heritability of complex traits and diseases, partition this heritability into functional categories, and estimate the genetic correlation between different phenotypes. Because the method relies on summary level results data, LD score regression is computationally tractable even for very large sample sizes. However, publicly available GWAS summary-level data are typically stored in different databases and have different formats, making it difficult to apply LD score regression to estimate genetic correlations across many different traits simultaneously. Results: In this manuscript, we describe LD Hub - a centralized database of summary-level GWAS results for 173 diseases/traits from different publicly available resources/consortia and a web interface that automates the LD score regression analysis pipeline. To demonstrate functionality and validate our software, we replicated previously reported LD score regression analyses of 49 traits/diseases using LD Hub; and estimated SNP heritability and the genetic correlation across the different phenotypes. We also present new results obtained by uploading a recent atopic dermatitis GWAS meta-analysis to examine the genetic correlation between the condition and other potentially related traits. In response to the growing availability of publicly accessible GWAS summary-level results data, our database and the accompanying web interface will ensure maximal uptake of the LD score regression methodology, provide a useful database for the public dissemination of GWAS results, and provide a method for easily screening hundreds of traits for overlapping genetic aetiologies
Glyphosate, Other Herbicides, And Transformation Products In Midwestern Streams, 2002
The use of glyphosate has increased rapidly, and there is limited understanding of its environmental fate. The objective of this study was to document the occurrence of glyphosate and the transformation product aminomethylphosphonic acid (AMPA) in Midwestern streams and to compare their occurrence with that of more commonly measured herbicides such as acetochlor, atrazine, and metolachlor. Water samples were collected at sites on 51 streams in nine Midwestern states in 2002 during three runoff events: after the application of pre-emergence herbicides, after the application of post-emergence herbicides, and during harvest season. All samples were analyzed for glyphosate and 20 other herbicides using gas chromatography/mass spectrometry or high performance liquid chromatography/mass spectrometry. The frequency of glyphosate and AMPA detection, range of concentrations in runoff samples, and ratios of AMPA to glyphosate concentrations did not vary throughout the growing season as substantially as for other herbicides like atrazine, probably because of different seasonal use patterns. Glyphosate was detected at or above 0.1 μg/l in 35 percent of pre-emergence, 40 percent of post-emergence, and 31 percent of harvest season samples, with a maximum concentration of 8.7 μg/l. AMPA was detected at or above 0.1 μg/l in 53 percent of pre-emergence, 83 percent of post-emergence, and 73 percent of harvest season samples, with a maximum concentration of 3.6 μg/l. Glyphosate was not detected at a concentration at or above the U.S. Environmental Protection Agency’s maximum contamination level (MCL) of 700 μg/l in any sample. Atrazine was detected at or above 0.1 μg/l in 94 percent of pre-emergence, 96 percent of postemergence, and 57 percent of harvest season samples, with a maximum concentration of 55 μg/l. Atrazine was detected at or above its MCL (3 μg/l) in 57 percent of pre-emergence and 33 percent of postemergence samples
Astroparticle Physics with a Customized Low-Background Broad Energy Germanium Detector
The MAJORANA Collaboration is building the MAJORANA DEMONSTRATOR, a 60 kg
array of high purity germanium detectors housed in an ultra-low background
shield at the Sanford Underground Laboratory in Lead, SD. The MAJORANA
DEMONSTRATOR will search for neutrinoless double-beta decay of 76Ge while
demonstrating the feasibility of a tonne-scale experiment. It may also carry
out a dark matter search in the 1-10 GeV/c^2 mass range. We have found that
customized Broad Energy Germanium (BEGe) detectors produced by Canberra have
several desirable features for a neutrinoless double-beta decay experiment,
including low electronic noise, excellent pulse shape analysis capabilities,
and simple fabrication. We have deployed a customized BEGe, the MAJORANA
Low-Background BEGe at Kimballton (MALBEK), in a low-background cryostat and
shield at the Kimballton Underground Research Facility in Virginia. This paper
will focus on the detector characteristics and measurements that can be
performed with such a radiation detector in a low-background environment.Comment: Submitted to NIMA Proceedings, SORMA XII. 9 pages, 4 figure
The absence of QCD -function factorization property of the generalized Crewther relation in the 't Hooft -based scheme
We apply the 't Hooft -based scheme to study the scheme-dependence
of the QCD generalization of Crewther relation for the product of the
normalised non-singlet perturbative contributions to the -annihilation
Adler function and to the Bjorken sum rule of the polarized lepton-nucleon
deep-inelastic scattering process. We prove that after the transformations from
the pure -scheme to the 't Hooft scheme the characteristic
-scheme theoretical property of this relation, namely the
factorization of the -function in its conformal symmetry breaking part,
disappears. Another "non-comfortable" theoretical consequence of the
application of this prescription in SUSY QED model is
mentioned. It is shown, that within the 't Hooft scheme the expansions of Green
functions in terms of the Lambert function is simplified in high orders of
perturbation theory. This may be considered as the attractive feature of the 't
Hooft scheme, which manifest itself in high-order perturbative phenomenological
applications.Comment: LateX, 10 pages, Title a bit modified, comments on the conservation
of vector current in the 't Hooft scheme added, 1 extra reference added,
accepted for publication in Phys. Lett.
iNOS activity is critical for the clearance of Burkholderia mallei from infected RAW 264.7 murine macrophages
Burkholderia mallei is a facultative intracellular pathogen that can cause fatal disease in animals and humans. To better understand the role of phagocytic cells in the control of infections caused by this organism, studies were initiated to examine the interactions of B. mallei with RAW 264.7 murine macrophages. Utilizing modified kanamycin-protection assays, B. mallei was shown to survive and replicate in RAW 264.7 cells infected at multiplicities of infection (moi) of ≤ 1. In contrast, the organism was efficiently cleared by the macrophages when infected at an moi of 10. Interestingly, studies demonstrated that the monolayers only produced high levels of TNF-α, IL-6, IL-10, GM-CSF, RANTES and IFN-β when infected at an moi of 10. In addition, nitric oxide assays and inducible nitric oxide synthase (iNOS) immunoblot analyses revealed a strong correlation between iNOS activity and clearance of B. mallei from RAW 264.7 cells. Furthermore, treatment of activated macrophages with the iNOS inhibitor, aminoguanidine, inhibited clearance of B. mallei from infected monolayers. Based upon these results, it appears that moi significantly influence the outcome of interactions between B. mallei and murine macrophages and that iNOS activity is critical for the clearance of B. mallei from activated RAW 264.7 cells
Equine Protozoal Myeloencephalitis: An Updated Consensus Statement with a Focus on Parasite Biology, Diagnosis, Treatment, and Prevention
Equine protozoal myeloencephalitis (EPM) remains an important neurologic disease of horses. There are no pathognomonic clinical signs for the disease. Affected horses can have focal or multifocal central nervous system (CNS) disease. EPM can be difficult to diagnose antemortem. It is caused by either of 2 parasites, Sarcocystis neurona and Neospora hughesi, with much less known about N. hughesi. Although risk factors such as transport stress and breed and age correlations have been identified, biologic factors such as genetic predispositions of individual animals, and parasite-specific factors such as strain differences in virulence, remain largely undetermined. This consensus statement update presents current published knowledge of the parasite biology, host immune response, disease pathogenesis, epidemiology, and risk factors. Importantly, the statement provides recommendations for EPM diagnosis, treatment, and prevention
Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment
This paper describes an analysis of the angular distribution of W->enu and
W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with
the ATLAS detector at the LHC in 2010, corresponding to an integrated
luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and
the missing transverse energy, the W decay angular distribution projected onto
the transverse plane is obtained and analysed in terms of helicity fractions
f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV
and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw
> 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour,
are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017
+/- 0.030, where the first uncertainties are statistical, and the second
include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables,
revised author list, matches European Journal of Physics C versio
Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS
The chi_b(nP) quarkonium states are produced in proton-proton collisions at
the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS
detector. Using a data sample corresponding to an integrated luminosity of 4.4
fb^-1, these states are reconstructed through their radiative decays to
Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks
corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new
structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is
also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes.
This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table,
corrected author list, matches final version in Physical Review Letter
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