55 research outputs found

    The transparency challenge of blockchain in organizations

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    This position paper discusses the challenges of blockchain applications in businesses and the public sector related to an excessive degree of transparency. We first point out the types of sensitive data involved in different patterns of blockchain use cases. We then argue that the implications of blockchains’ information exposure caused by replicated transaction storage and execution go well beyond the often-mentioned conflicts with the GDPR’s “right to be forgotten” and may be more problematic than anticipated. In particular, we illustrate the trade-off between protecting sensitive information and increasing process efficiency through smart contracts. We also explore to which extent permissioned blockchains and novel applications of cryptographic technologies such as self-sovereign identities and zero-knowledge proofs can help overcome the transparency challenge and thus act as catalysts for blockchain adoption and diffusion in organizations

    Trehalose Biosynthesis Promotes Pseudomonas aeruginosa Pathogenicity in Plants

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    Pseudomonas aeruginosa strain PA14 is a multi-host pathogen that infects plants, nematodes, insects, and vertebrates. Many PA14 factors are required for virulence in more than one of these hosts. Noting that plants have a fundamentally different cellular architecture from animals, we sought to identify PA14 factors that are specifically required for plant pathogenesis. We show that synthesis by PA14 of the disaccharide trehalose is required for pathogenesis in Arabidopsis, but not in nematodes, insects, or mice. In-frame deletion of two closely-linked predicted trehalose biosynthetic operons, treYZ and treS, decreased growth in Arabidopsis leaves about 50 fold. Exogenously co-inoculated trehalose, ammonium, or nitrate, but not glucose, sulfate, or phosphate suppressed the phenotype of the double ΔtreYZΔtreS mutant. Exogenous trehalose or ammonium nitrate does not suppress the growth defect of the double ΔtreYZΔtreS mutant by suppressing the plant defense response. Trehalose also does not function intracellularly in P. aeruginosa to ameliorate a variety of stresses, but most likely functions extracellularly, because wild-type PA14 rescued the in vivo growth defect of the ΔtreYZΔtreS in trans. Surprisingly, the growth defect of the double ΔtreYZΔtreS double mutant was suppressed by various Arabidopsis cell wall mutants that affect xyloglucan synthesis, including an xxt1xxt2 double mutant that completely lacks xyloglucan, even though xyloglucan mutants are not more susceptible to pathogens and respond like wild-type plants to immune elicitors. An explanation of our data is that trehalose functions to promote the acquisition of nitrogen-containing nutrients in a process that involves the xyloglucan component of the plant cell wall, thereby allowing P. aeruginosa to replicate in the intercellular spaces in a leaf. This work shows how P. aeruginosa, a multi-host opportunistic pathogen, has repurposed a highly conserved “house-keeping” anabolic pathway (trehalose biosynthesis) as a potent virulence factor that allows it to replicate in the intercellular environment of a leaf

    Soluble amyloid beta levels are elevated in the white matter of Alzheimer’s patients, independent of cortical plaque severity

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    Alzheimer’s disease (AD) is the most common neurodegenerative disease and the leading cause of dementia. In addition to grey matter pathology, white matter changes are now recognized as an important pathological feature in the emergence of the disease. Despite growing recognition of the importance of white matter abnormalities in the pathogenesis of AD, the causes of white matter degeneration are still unknown. While multiple studies propose Wallerian-like degeneration as the source of white matter change, others suggest that primary white matter pathology may be due, at least in part, to other mechanisms, including local effects of toxic Aβ peptides. In the current study, we investigated levels of soluble amyloid-beta (Aβ) in white matter of AD patients (n=12) compared with controls (n=10). Fresh frozen white matter samples were obtained from anterior (Brodmann area 9) and posterior (Brodmann area 1, 2 and 3) areas of post-mortem AD and control brains. ELISA was used to examine levels of soluble Aβ -42 and Aβ -40. Total cortical neuritic plaque severity rating was derived from individual ratings in the following areas of cortex: mid-frontal, superior temporal, pre-central, inferior parietal, hippocampus (CA1), subiculum, entorhinal cortex, transentorhinal cortex, inferior temporal, amygdala and basal forebrain. Compared with controls, AD samples had higher white matter levels of both soluble Aβ -42 and Aβ -40. While no regional white matter differences were found in Aβ -40, Aβ -42 levels were higher in anterior regions than in posterior regions across both groups. After statistically controlling for total cortical neuritic plaque severity, differences in both soluble Aβ -42 and Aβ -40 between the groups remained, suggesting that white matter Aβ peptides accumulate independent of overall grey matter fibrillar amyloid pathology and are not simply a reflection of overall amyloid burden. These results shed light on one potential mechanism through which white matter degeneration may occur in AD. Given that white matter degeneration may be an early marker of disease, preceding grey matter atrophy, understanding the mechanisms and risk factors that may lead to white matter loss could help to identify those at high risk and to intervene earlier in the pathogenic process

    Think globally, measure locally: The MIREN standardized protocol for monitoring plant species distributions along elevation gradients

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    Climate change and other global change drivers threaten plant diversity in mountains worldwide. A widely documented response to such environmental modifications is for plant species to change their elevational ranges. Range shifts are often idiosyncratic and difficult to generalize, partly due to variation in sampling methods. There is thus a need for a standardized monitoring strategy that can be applied across mountain regions to assess distribution changes and community turnover of native and non-native plant species over space and time. Here, we present a conceptually intuitive and standardized protocol developed by the Mountain Invasion Research Network (MIREN) to systematically quantify global patterns of native and non-native species distributions along elevation gradients and shifts arising from interactive effects of climate change and human disturbance. Usually repeated every five years, surveys consist of 20 sample sites located at equal elevation increments along three replicate roads per sampling region. At each site, three plots extend from the side of a mountain road into surrounding natural vegetation. The protocol has been successfully used in 18 regions worldwide from 2007 to present. Analyses of one point in time already generated some salient results, and revealed region-specific elevational patterns of native plant species richness, but a globally consistent elevational decline in non-native species richness. Non-native plants were also more abundant directly adjacent to road edges, suggesting that disturbed roadsides serve as a vector for invasions into mountains. From the upcoming analyses of time series, even more exciting results can be expected, especially about range shifts. Implementing the protocol in more mountain regions globally would help to generate a more complete picture of how global change alters species distributions. This would inform conservation policy in mountain ecosystems, where some conservation policies remain poorly implemented

    Design and baseline characteristics of the finerenone in reducing cardiovascular mortality and morbidity in diabetic kidney disease trial

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    Background: Among people with diabetes, those with kidney disease have exceptionally high rates of cardiovascular (CV) morbidity and mortality and progression of their underlying kidney disease. Finerenone is a novel, nonsteroidal, selective mineralocorticoid receptor antagonist that has shown to reduce albuminuria in type 2 diabetes (T2D) patients with chronic kidney disease (CKD) while revealing only a low risk of hyperkalemia. However, the effect of finerenone on CV and renal outcomes has not yet been investigated in long-term trials. Patients and Methods: The Finerenone in Reducing CV Mortality and Morbidity in Diabetic Kidney Disease (FIGARO-DKD) trial aims to assess the efficacy and safety of finerenone compared to placebo at reducing clinically important CV and renal outcomes in T2D patients with CKD. FIGARO-DKD is a randomized, double-blind, placebo-controlled, parallel-group, event-driven trial running in 47 countries with an expected duration of approximately 6 years. FIGARO-DKD randomized 7,437 patients with an estimated glomerular filtration rate >= 25 mL/min/1.73 m(2) and albuminuria (urinary albumin-to-creatinine ratio >= 30 to <= 5,000 mg/g). The study has at least 90% power to detect a 20% reduction in the risk of the primary outcome (overall two-sided significance level alpha = 0.05), the composite of time to first occurrence of CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure. Conclusions: FIGARO-DKD will determine whether an optimally treated cohort of T2D patients with CKD at high risk of CV and renal events will experience cardiorenal benefits with the addition of finerenone to their treatment regimen. Trial Registration: EudraCT number: 2015-000950-39; ClinicalTrials.gov identifier: NCT02545049

    Mudança científica: modelos filosóficos e pesquisa histórica

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    Autism or autisms? The clinical manifestations and classification of autism spectrum disorders

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    Thesis (M.A.)--Boston University PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at [email protected]. Thank you.Individuals with Autism Spectrum Disorders (autistic disorder, Asperger's disorder, childhood disintegrative disorder, and pervasive developmental disorder - not otherwise specified) are a very heterogeneous group. The disorders on the spectrum are behaviorally defined (according to the American Psychiatric Association's Diagnostic and Statistical Manual-IV, Text Revision) with specific behaviors falling within categories. For autistic disorder, the categories reflect the core deficits of social interaction, communication, and restricted or repetitive behaviors or interests ("CDC- Autism Spectrum Disorder (ASDs)- NCBDDD," n.d.). The behaviors that fall within these categories have been carefully researched and described in order to allow for uniformity in diagnosis and the discussion of causality in research. The diagnosis of Autism Spectrum Disorders (ASD) relies on established thresholds within these categories, with the clinician responsible for characterizing and counting the number of behaviors that are present and in which category they fall. Other associated symptoms (low IQ, language impairments, epilepsy, and others) are often present, and while not diagnostic of ASD, can contribute much to the phenotypic heterogeneity. As a result, individuals who exhibit different behavioral symptoms might be diagnostically indistinguishable. This thesis is intended to be a critical review of the current state of autism research. In the different sections (Phenotype, Epidemiology, Genetics, Cellular/Molecular Mechanisms, Neural Circuits, and Therapeutics), the discussion is focused on what has been firmly established in the field. In many cases, what is known about autism leads to a better understanding of how to subdivide the population. Genetics, for instance, can divide autism into syndromic or idiopathic cases (those associated with a comorbid genetic condition such as Rett's Syndrome or Fragile X and those that have no apparent genetic etiology, respectively). Epidemiology research has shown that a host of chemical, social, and emotional exposures are correlated with varied risks of developing autism (leading to possible distinctions between autism caused by teratogens or autism caused by other mechanisms). Molecular research has revealed a subset of autistic individuals who have various causes of synaptic dysfunction, and within this group there have been certain proteins implicated, offering additional points of differentiation between individuals. The study of therapeutics, however, has largely left the population as a whole in research. As a result, the comparisons (based on mean differences between controls and ASD subjects) are not fine-grained enough to show benefits within certain subgroups of ASD individuals. What the research shows is that the autism spectrum can (and should) be subdivided. Establishing multiple well-defined "autisms" allows for much more targeted research. The first step is creating clear boundaries to the spectrum, and the proposed revisions to the Fifth Edition of the Diagnostic and Statistical Manual is intended to do just this (collapsing the spectrum disorders into one diagnosis with a streamlined set of common behavioral features). The answer to the "autism or autisms?" questions is both: once the spectrum is clearly distinguished from the non-spectrum, research will establish the points at which autism should be subdivided. Homogeneous subgroups (however they are defined) will allow for more robust study of the underlying pathophysiology and possible treatment options

    Data from: The NBS-LRR architectures of plant R-proteins and metazoan NLRs evolved in independent events

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    There are intriguing parallels between plants and animals, with respect to the structures of their innate immune receptors, that suggest universal principles of innate immunity. The cytosolic nucleotide binding site–leucine rich repeat (NBS-LRR) resistance proteins of plants (R-proteins) and the so-called NOD-like receptors of animals (NLRs) share a domain architecture that includes a STAND (signal transduction ATPases with numerous domains) family NTPase followed by a series of LRRs, suggesting inheritance from a common ancestor with that architecture. Focusing on the STAND NTPases of plant R-proteins, animal NLRs, and their homologs that represent the NB-ARC (nucleotide-binding adaptor shared by APAF-1, certain R gene products and CED-4) and NACHT (named for NAIP, CIIA, HET-E, and TEP1) subfamilies of the STAND NTPases, we analyzed the phylogenetic distribution of the NBS-LRR domain architecture, used maximum-likelihood methods to infer a phylogeny of the NTPase domains of R-proteins, and reconstructed the domain structure of the protein containing the common ancestor of the STAND NTPase domain of R-proteins and NLRs. Our analyses reject monophyly of plant R-proteins and NLRs and suggest that the protein containing the last common ancestor of the STAND NTPases of plant R-proteins and animal NLRs (and, by extension, all NB-ARC and NACHT domains) possessed a domain structure that included a STAND NTPase paired with a series of tetratricopeptide repeats. These analyses reject the hypothesis that the domain architecture of R-proteins and NLRs was inherited from a common ancestor and instead suggest the domain architecture evolved at least twice. It remains unclear whether the NBS-LRR architectures were innovations of plants and animals themselves or were acquired by one or both lineages through horizontal gene transfer

    Urbach_and_Ausubel_PNAS_2017_20170104

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    Scripts and data files associated with Urbach and Ausubel PNAS 201
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