82 research outputs found
Timing attack detection on BACnet via a machine learning approach
Building Automation Systems (BAS), alternatively known as Building Management Systems (BMS), which centralise the management of building services, are often connected to corporate networks and are routinely accessed remotely for operational management and emergency purposes. The protocols used in BAS, in particular BACnet, were not designed with security as a primary requirement, thus the majority of systems operate with sub-standard or non-existent security implementations. As intrusion is thus likely easy to achieve, intrusion detection systems should be put in place to ensure they can be detected and mitigated. Existing intrusion detection systems typically deal only with known threats (signature-based approaches) or suffer from a high false positive rate (anomaly-based approaches). In this paper we present an overview of the problem space with respect to BAS, and suggest that state aware machine learning techniques could be used to discover threats that comprise a collection of legitimate commands. We provide a first step showing that the concept can be used to detect an attack where legitimate write commands being sent in rapid succession may cause system failure. We capture the state as a ‘time since last write’ event and use a basic artificial neural network classifier to detect attacks
Clean Kinematic Samples in Dwarf Spheroidals: An Algorithm for Evaluating Membership and Estimating Distribution Parameters When Contamination is Present
(abridged) We develop an algorithm for estimating parameters of a
distribution sampled with contamination, employing a statistical technique
known as ``expectation maximization'' (EM). Given models for both member and
contaminant populations, the EM algorithm iteratively evaluates the membership
probability of each discrete data point, then uses those probabilities to
update parameter estimates for member and contaminant distributions. The EM
approach has wide applicability to the analysis of astronomical data. Here we
tailor an EM algorithm to operate on spectroscopic samples obtained with the
Michigan-MIKE Fiber System (MMFS) as part of our Magellan survey of stellar
radial velocities in nearby dwarf spheroidal (dSph) galaxies. These samples are
presented in a companion paper and contain discrete measurements of
line-of-sight velocity, projected position, and Mg index for ~1000 - 2500 stars
per dSph, including some fraction of contamination by foreground Milky Way
stars. The EM algorithm quantifies both dSph and contaminant distributions,
returning maximum-likelihood estimates of the means and variances, as well as
the probability that each star is a dSph member. Applied to our MMFS data, the
EM algorithm identifies more than 5000 probable dSph members. We test the
performance of the EM algorithm on simulated data sets that represent a range
of sample size, level of contamination, and amount of overlap between dSph and
contaminant velocity distributions. The simulations establish that for samples
ranging from large (N ~3000) to small (N~30), the EM algorithm distinguishes
members from contaminants and returns accurate parameter estimates much more
reliably than conventional methods of contaminant removal (e.g., sigma
clipping).Comment: Accepted for publication in The Astronomical Journal. Download pdf
with full-resolution figures from
http://www.ast.cam.ac.uk/~walker/dsph_em.pd
Disease transmission promotes evolution of host spatial patterns
Ecological dynamics can produce a variety of striking patterns. On ecological time scales, pattern formation has been hypothesized to be due to the interaction between a species and its local environment. On longer time scales, evolutionary factors must be taken into account. To examine the evolutionary robustness of spatial pattern formation, we construct a spatially explicit model of vegetation in the presence of a pathogen. Initially, we compare the dynamics for vegetation parameters that lead to competition induced spatial patterns and those that do not. Over ecological time scales, banded spatial patterns dramatically reduced the ability of the pathogen to spread, lowered its endemic density and hence increased the persistence of the vegetation. To gain an evolutionary understanding, each plant was given a heritable trait defining its resilience to competition; greater competition leads to lower vegetation density but stronger spatial patterns. When a disease is introduced, the selective pressure on the plant's resilience to the competition parameter is determined by the transmission of the disease. For high transmission, vegetation that has low resilience to competition and hence strong spatial patterning is an evolutionarily stable strategy. This demonstrates a novel mechanism by which striking spatial patterns can be maintained by disease-driven selection
The R-Process Alliance: Abundance Universality among Some Elements at and between the First and Second R-Process Peaks
We present new observational benchmarks of rapid neutron-capture process
(r-process) nucleosynthesis for elements at and between the first (A ~ 80) and
second (A ~ 130) peaks. Our analysis is based on archival ultraviolet and
optical spectroscopy of eight metal-poor stars with Se (Z = 34) or Te (Z = 52)
detections, whose r-process enhancement varies by more than a factor of 30
(-0.22 <= [Eu/Fe] <= +1.32). We calculate ratios among the abundances of Se, Sr
through Mo (38 <= Z <= 42), and Te. These benchmarks may offer a new empirical
alternative to the predicted solar system r-process residual pattern. The Te
abundances in these stars correlate more closely with the lighter r-process
elements than the heavier ones, contradicting and superseding previous
findings. The small star-to-star dispersion among the abundances of Se, Sr, Y,
Zr, Nb, Mo, and Te (<= 0.13 dex, or 26%) matches that observed among the
abundances of the lanthanides and third r-process-peak elements. The concept of
r-process universality that is recognized among the lanthanide and third-peak
elements in r-process-enhanced stars may also apply to Se, Sr, Y, Zr, Nb, Mo,
and Te, provided the overall abundances of the lighter r-process elements are
scaled independently of the heavier ones. The abundance behavior of the
elements Ru through Sn (44 <= Z <= 50) requires further study. Our results
suggest that at least one relatively common source in the early Universe
produced a consistent abundance pattern among some elements spanning the first
and second r-process peaks.Comment: 16 pages, 3 figures, including 4 appendices. Published in the
Astrophysical Journa
Palliative care early in the care continuum among patients with serious respiratory illness an official ATS/AAHPM/HPNA/SWHPN policy statement
Background:
Patients with serious respiratory illness and their caregivers suffer considerable burdens, and palliative care is a fundamental right for anyone who needs it. However, the overwhelming majority of patients do not receive timely palliative care before the end of life, despite robust evidence for improved outcomes.
Goals:
This policy statement by the American Thoracic Society (ATS) and partnering societies advocates for improved integration of high-quality palliative care early in the care continuum for patients with serious respiratory illness and their caregivers and provides clinicians and policymakers with a framework to accomplish this.
Methods:
An international and interprofessional expert committee, including patients and caregivers, achieved consensus across a diverse working group representing pulmonary–critical care, palliative care, bioethics, health law and policy, geriatrics, nursing, physiotherapy, social work, pharmacy, patient advocacy, psychology, and sociology.
Results:
The committee developed fundamental values, principles, and policy recommendations for integrating palliative care in serious respiratory illness care across seven domains: 1) delivery models, 2) comprehensive symptom assessment and management, 3) advance care planning and goals of care discussions, 4) caregiver support, 5) health disparities, 6) mass casualty events and emergency preparedness, and 7) research priorities. The recommendations encourage timely integration of palliative care, promote innovative primary and secondary or specialist palliative care delivery models, and advocate for research and policy initiatives to improve the availability and quality of palliative care for patients and their caregivers.
Conclusions:
This multisociety policy statement establishes a framework for early palliative care in serious respiratory illness and provides guidance for pulmonary–critical care clinicians and policymakers for its proactive integration
Varespladib and cardiovascular events in patients with an acute coronary syndrome: the VISTA-16 randomized clinical trial
IMPORTANCE: Secretory phospholipase A2(sPLA2) generates bioactive phospholipid products implicated in atherosclerosis. The sPLA2inhibitor varespladib has favorable effects on lipid and inflammatory markers; however, its effect on cardiovascular outcomes is unknown. OBJECTIVE: To determine the effects of sPLA2inhibition with varespladib on cardiovascular outcomes. DESIGN, SETTING, AND PARTICIPANTS: A double-blind, randomized, multicenter trial at 362 academic and community hospitals in Europe, Australia, New Zealand, India, and North America of 5145 patients randomized within 96 hours of presentation of an acute coronary syndrome (ACS) to either varespladib (n = 2572) or placebo (n = 2573) with enrollment between June 1, 2010, and March 7, 2012 (study termination on March 9, 2012). INTERVENTIONS: Participants were randomized to receive varespladib (500 mg) or placebo daily for 16 weeks, in addition to atorvastatin and other established therapies. MAIN OUTCOMES AND MEASURES: The primary efficacy measurewas a composite of cardiovascular mortality, nonfatal myocardial infarction (MI), nonfatal stroke, or unstable angina with evidence of ischemia requiring hospitalization at 16 weeks. Six-month survival status was also evaluated. RESULTS: At a prespecified interim analysis, including 212 primary end point events, the independent data and safety monitoring board recommended termination of the trial for futility and possible harm. The primary end point occurred in 136 patients (6.1%) treated with varespladib compared with 109 patients (5.1%) treated with placebo (hazard ratio [HR], 1.25; 95%CI, 0.97-1.61; log-rank P = .08). Varespladib was associated with a greater risk of MI (78 [3.4%] vs 47 [2.2%]; HR, 1.66; 95%CI, 1.16-2.39; log-rank P = .005). The composite secondary end point of cardiovascular mortality, MI, and stroke was observed in 107 patients (4.6%) in the varespladib group and 79 patients (3.8%) in the placebo group (HR, 1.36; 95% CI, 1.02-1.82; P = .04). CONCLUSIONS AND RELEVANCE: In patients with recent ACS, varespladib did not reduce the risk of recurrent cardiovascular events and significantly increased the risk of MI. The sPLA2inhibition with varespladib may be harmful and is not a useful strategy to reduce adverse cardiovascular outcomes after ACS. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01130246. Copyright 2014 American Medical Association. All rights reserved
The education effect: higher educational qualifications are robustly associated with beneficial personal and socio-political outcomes
Level of education is a predictor of a range of important outcomes, such as political interest and cynicism, social trust, health, well-being, and intergroup attitudes. We address a gap in the literature by analyzing the strength and stability of the education effect associated with this diverse range of outcomes across three surveys covering the period 1986–2011, including novel latent growth analyses of the stability of the education effect within the same individuals over time. Our analyses of the British Social Attitudes Survey, British Household Panel Survey, and International Social Survey Programme indicated that the education effect was robust across these outcomes and relatively stable over time, with higher education levels being associated with higher trust and political interest, better health and well-being, and with less political cynicism and less negative intergroup attitudes. The education effect was strongest when associated with political outcomes and attitudes towards immigrants, whereas it was weakest when associated with health and well-being. Most of the education effect appears to be due to the beneficial consequences of having a university education. Our results demonstrate that this beneficial education effect is also manifested in within-individual changes, with the education effect tending to become stronger as individuals age
Updated Guidance Regarding The Risk ofAllergic Reactions to COVID-19 Vaccines and Recommended Evaluation and Management: A GRADE Assessment, and International Consensus Approach
This guidance updates 2021 GRADE (Grading of Recommendations Assessment, Development and Evaluation) recommendations regarding immediate allergic reactions following coronavirus disease 2019 (COVID-19) vaccines and addresses revaccinating individuals with first-dose allergic reactions and allergy testing to determine revaccination outcomes. Recent meta-analyses assessed the incidence of severe allergic reactions to initial COVID-19 vaccination, risk of mRNA-COVID-19 revaccination after an initial reaction, and diagnostic accuracy of COVID-19 vaccine and vaccine excipient testing in predicting reactions. GRADE methods informed rating the certainty of evidence and strength of recommendations. A modified Delphi panel consisting of experts in allergy, anaphylaxis, vaccinology, infectious diseases, emergency medicine, and primary care from Australia, Canada, Europe, Japan, South Africa, the United Kingdom, and the United States formed the recommendations. We recommend vaccination for persons without COVID-19 vaccine excipient allergy and revaccination after a prior immediate allergic reaction. We suggest against \u3e 15-minute postvaccination observation. We recommend against mRNA vaccine or excipient skin testing to predict outcomes. We suggest revaccination of persons with an immediate allergic reaction to the mRNA vaccine or excipients be performed by a person with vaccine allergy expertise in a properly equipped setting. We suggest against premedication, split-dosing, or special precautions because of a comorbid allergic history
Palliative care early in the care continuum among patients with serious respiratory illness - An official ATS/AAHPM/HPNA/SWHPN policy statement
Background: Patients with serious respiratory illness and their caregivers suffer considerable burdens, and palliative care is a fundamental right for anyone who needs it. However, the overwhelming majority of patients do not receive timely palliative care before the end of life, despite robust evidence for improved outcomes. Goals: This policy statement by the American Thoracic Society (ATS) and partnering societies advocates for improved integration of high-quality palliative care early in the care continuum for patients with serious respiratory illness and their caregivers and provides clinicians and policymakers with a framework to accomplish this. Methods: An international and interprofessional expert committee, including patients and caregivers, achieved consensus across a diverse working group representing pulmonary–critical care, palliative care, bioethics, health law and policy, geriatrics, nursing, physiotherapy, social work, pharmacy, patient advocacy, psychology, and sociology. Results: The committee developed fundamental values, principles, and policy recommendations for integrating palliative care in serious respiratory illness care across seven domains: 1) delivery models, 2) comprehensive symptom assessment and management, 3) advance care planning and goals of care discussions, 4) caregiver support, 5) health disparities, 6) mass casualty events and emergency preparedness, and 7) research priorities. The recommendations encourage timely integration of palliative care, promote innovative primary and secondary or specialist palliative care delivery models, and advocate for research and policy initiatives to improve the availability and quality of palliative care for patients and their caregivers. Conclusions: This multisociety policy statement establishes a framework for early palliative care in serious respiratory illness and provides guidance for pulmonary–critical care clinicians and policymakers for its proactive integration
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