97,303 research outputs found

    Robust Linear Regression Analysis - A Greedy Approach

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    The task of robust linear estimation in the presence of outliers is of particular importance in signal processing, statistics and machine learning. Although the problem has been stated a few decades ago and solved using classical (considered nowadays) methods, recently it has attracted more attention in the context of sparse modeling, where several notable contributions have been made. In the present manuscript, a new approach is considered in the framework of greedy algorithms. The noise is split into two components: a) the inlier bounded noise and b) the outliers, which are explicitly modeled by employing sparsity arguments. Based on this scheme, a novel efficient algorithm (Greedy Algorithm for Robust Denoising - GARD), is derived. GARD alternates between a least square optimization criterion and an Orthogonal Matching Pursuit (OMP) selection step that identifies the outliers. The case where only outliers are present has been studied separately, where bounds on the \textit{Restricted Isometry Property} guarantee that the recovery of the signal via GARD is exact. Moreover, theoretical results concerning convergence as well as the derivation of error bounds in the case of additional bounded noise are discussed. Finally, we provide extensive simulations, which demonstrate the comparative advantages of the new technique

    Twenty years of "Lipid World": a fertile partnership with David Deamer

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    "The Lipid World" was published in 2001, stemming from a highly effective collaboration with David Deamer during a sabbatical year 20 years ago at the Weizmann Institute of Science in Israel. The present review paper highlights the benefits of this scientific interaction and assesses the impact of the lipid world paper on the present understanding of the possible roles of amphiphiles and their assemblies in the origin of life. The lipid world is defined as a putative stage in the progression towards life's origin, during which diverse amphiphiles or other spontaneously aggregating small molecules could have concurrently played multiple key roles, including compartment formation, the appearance of mutually catalytic networks, molecular information processing, and the rise of collective self-reproduction and compositional inheritance. This review brings back into a broader perspective some key points originally made in the lipid world paper, stressing the distinction between the widely accepted role of lipids in forming compartments and their expanded capacities as delineated above. In the light of recent advancements, we discussed the topical relevance of the lipid worldview as an alternative to broadly accepted scenarios, and the need for further experimental and computer-based validation of the feasibility and implications of the individual attributes of this point of view. Finally, we point to possible avenues for exploring transition paths from small molecule-based noncovalent structures to more complex biopolymer-containing proto-cellular systems.711473 - Minerva Foundation; 80NSSC17K0295, 80NSSC17K0296, 1724150 - National Science FoundationPublished versio

    Observational Evidence For Constant Gas Accretion Rate Since z = 5

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    Star formation rate density (SFRD) has not been constant throughout the history of the Universe. The rate at which stars form greatly affects the evolution of the Universe, but the factors which drive SFRD evolution remain uncertain. There must be sufficient amount of gas to fuel the star formation, either as a reservoir within a galaxy, or as inflow from the intergalactic medium (IGM). This work explores how the gas accretion rate onto galaxies over time has affected star formation rate. We propose a novel method of measuring cosmic gas accretion rate. This involves comparing the comoving densities of available Hi and H2 gas and the densities of existing stars at different redshifts. We constrained gas accretion until z = 5, and we found that the gas accretion rate density (GARD) is relatively constant in the range from z = 5 to z = 0. This constancy in the GARD is not reflected by the SFRD, which declines significantly between z = 1.0 and z = 0. This work suggests that the decline is not due to a reduction in GARD.Comment: 7 pages including appendices, 2 figures in main text, 3 further figures in appendice

    A critical perspective on stigma in physiotherapy: the example of weight stigma

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    "Manipulating practices is the first ever collection of critical physiotherapy studies and comes at a time of unprecedented change in the profession. Written as a collaboration between 20 authors, many members of the Critical Physiotherapy Network (CPN), the book uncovers the growing body of critical thinking now emerging in physiotherapy. From topics as diverse as 21st century education, ethics, evidence-based practice, touch, and equine therapy; and approaches as varied as disability and performance studies, feminism, logic, narrative theory, new materialism, and phenomenology, the book explores ways of thinking ‘otherwise’ about physiotherapy. Over 16 chapters written by authors from six different countries, Manipulating practices offers insights from some of physiotherapy’s most radical thinkers. The book is also an innovative venture into open source publishing, making it entirely free to download and read. In keeping with the objectives of the CPN, the chapters expose a range of concepts, ideas and practices to critical scrutiny, and reflect the profession’s growing interest in critiquing taken-for-granted ways of practicing and thinking. Manipulating practices will be of interest to clinicians, lecturers, policy-makers, researchers and students, and will provide new impetus to help physiotherapists imagine how the profession might grow and develop into the future.""«Manipulating practices» er den første vitenskapelige antologien som samler kritiske studier innen fysioterapi, og lanseres i en tid der profesjonen er preget av store forandringer. Antologien representerer et samarbeidsprosjekt mellom 20 forskere, hvor majoriteten er medlemmer av Critical Physiotherapy Network (CNP) – et internasjonalt nettverk av forskere og klinikere fra hele verden. Antologien synliggjør den økende tendensen til kritisk tenkning som er i ferd med å vokse frem innenfor fysioterapi. Gjennom å fokusere på varierte tema som utdanning, etikk, evidensbasert praksis, berøring og terapiridning, samt en bred tilnærming som inkluderer funksjonshemming, performance-studier, feminisme, logikk, narrativ teori, ny materialisme og fenomenologi, utforsker antologien nye og annerledes tanker om fysioterapi som fag og profesjon. Antologiens 16 kapitler er skrevet av forskere fra seks ulike land og gir innsikt i forskningen til noen av de mest radikale forskerne i det internasjonale fysioterapimiljøet. Boken er også innovativ gjennom at den publiseres som open access, hvilket betyr at den kan lastes ned og leses gratis og dermed gjøres allment tilgjengelig. I tråd med ambisjonen for CPN, utforskes en rekke ulike begreper, ideer og praktiske tilnærminger relatert til kritisk tenkning innenfor fysioterapi. Slik gjenspeiles også profesjonens økende interesse for å kritisere etablerte måter å praktisere og tenke på, som tidligere har vært tatt for gitt. «Manipulating practices» vil være av interesse for forskere, klinikere, forelesere, politikere og studenter. Antologien vil forhåpentligvis bidra med nye impulser med henblikk på hvordan fysioterapiprofesjonen vil vokse og utvikle seg fremover.

    Anti-transpirant effects on vine physiology, berry and wine composition of cv. Aglianico (Vitis vinifera L.) Grown in South Italy

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    In viticulture, global warming requires reconsideration of current production models. At the base of this need there are some emerging phenomena: modification of phenological phases; acceleration of the maturation process of grapes, with significant increases in the concentration of sugar musts; decoupling between technological grape maturity and phenolic maturity. The aim of our study was to evaluate the effect of a natural anti-transpirant on grapevine physiology, berry, and wine composition of Aglianico cultivar. For two years, Aglianico vines were treated at veraison with the anti-transpirant Vapor Gard and compared with a control sprayed with only water. A bunch thinning was also applied to both treatments. The effectiveness of Vapor Gard were assessed through measurements of net photosynthesis and transpiration and analyzing the vegetative, productive and qualitative parameters. The results demonstrate that the application of antitranspirant reduced assimilation and transpiration rate, stomatal conductance, berry sugar accumulation, and wine alcohol content. No significant differences between treatments were observed for other berry and wine compositional parameters. This method may be a useful tool to reduce berry sugar content and to produce wines with a lower alcohol content

    Synthetic chemistry and biological activity of pentafluorosulphanyl (SF5) organic molecules

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    Acknowledgements We thank the European Commission for financial support (Industry Academia Partnerships and Pathways project “PET BRAIN”, Contract No 251482). S.A. thanks the Northern Research Partnership (www.northscotland-research.ac.uk/) and Pharmaness (www.pharmaness.it) for co-funding a PhD studentship.Peer reviewedPostprin
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