2,928 research outputs found
Radiocarbon Date List XI: Radiocarbon Dates from Marine Sediment Cores of the Iceland, Greenland, and Northeast Canadian Arctic Shelves and Nares Strait
Radiocarbon Date List XI contains an annotated listing of 178 AMS radiocarbon dates on samples from marine (169 samples) and lake (9 samples) sediment cores. Marine sediment cores, from which the samples for dating were taken, were collected on the Greenland Shelf, Baffin Bay, and the Eastern Canadian Arctic shelf. About 80% of the marine samples for dating were collected on the SW to N Icelandic shelf. The lake sediment cores were collected in northwestern Iceland. For dating of the marine samples, we submitted molluscs (117 samples), benthic and planktic foraminifera (45 samples), plant macrofauna (3 samples), and one serpulid worm. For dating of the lake cores, we submitted wood (8 samples) and one peat sample. The Conventional Radiocarbon Ages range from 294±9114C yr BP to 34,600±640 14C yr BP. The dates have been used to address a variety of research questions. The dates constrain the timing of high northern latitude late Quaternary environmental fluctuations, which include glacier extent, sea level history, isostatic rebound, sediment input, and ocean circulation. The dates also allowed assessment of the accuracy of commonly used reservoir correction. The samples were submitted by INSTAAR and affiliated researchers
Benchmarking Adversarially Robust Quantum Machine Learning at Scale
Machine learning (ML) methods such as artificial neural networks are rapidly
becoming ubiquitous in modern science, technology and industry. Despite their
accuracy and sophistication, neural networks can be easily fooled by carefully
designed malicious inputs known as adversarial attacks. While such
vulnerabilities remain a serious challenge for classical neural networks, the
extent of their existence is not fully understood in the quantum ML setting. In
this work, we benchmark the robustness of quantum ML networks, such as quantum
variational classifiers (QVC), at scale by performing rigorous training for
both simple and complex image datasets and through a variety of high-end
adversarial attacks. Our results show that QVCs offer a notably enhanced
robustness against classical adversarial attacks by learning features which are
not detected by the classical neural networks, indicating a possible quantum
advantage for ML tasks. Contrarily, and remarkably, the converse is not true,
with attacks on quantum networks also capable of deceiving classical neural
networks. By combining quantum and classical network outcomes, we propose a
novel adversarial attack detection technology. Traditionally quantum advantage
in ML systems has been sought through increased accuracy or algorithmic
speed-up, but our work has revealed the potential for a new kind of quantum
advantage through superior robustness of ML models, whose practical realisation
will address serious security concerns and reliability issues of ML algorithms
employed in a myriad of applications including autonomous vehicles,
cybersecurity, and surveillance robotic systems.Comment: 10 pages, 5 Figure
Improving Rates of Influenza Vaccination Through Electronic Health Record Portal Messages, Interactive Voice Recognition Calls and Patient-Enabled Electronic Health Record Updates: Protocol for a Randomized Controlled Trial
BACKGROUND: Clinical decision support (CDS), including computerized reminders for providers and patients, can improve health outcomes. CDS promoting influenza vaccination, delivered directly to patients via an electronic health record (EHR) patient portal and interactive voice recognition (IVR) calls, offers an innovative approach to improving patient care.
OBJECTIVE: To test the effectiveness of an EHR patient portal and IVR outreach to improve rates of influenza vaccination in a large multispecialty group practice in central Massachusetts.
METHODS: We describe a nonblinded, randomized controlled trial of EHR patient portal messages and IVR calls designed to promote influenza vaccination. In our preparatory phase, we conducted qualitative interviews with patients, providers, and staff to inform development of EHR portal messages with embedded questionnaires and IVR call scripts. We also provided practice-wide education on influenza vaccines to all physicians and staff members, including information on existing vaccine-specific EHR CDS. Outreach will target adult patients who remain unvaccinated for more than 2 months after the start of the influenza season. Using computer-generated randomization and a factorial design, we will assign 20,000 patients who are active users of electronic patient portals to one of the 4 study arms: (1) receipt of a portal message promoting influenza vaccines and offering online appointment scheduling; (2) receipt of an IVR call with similar content but without appointment facilitation; (3) both (1) and (2); or (4) neither (1) nor (2) (usual care). We will randomize patients without electronic portals (10,000 patients) to (1) receipt of IVR call or (2) usual care. Both portal messages and IVR calls promote influenza vaccine completion. Our primary outcome is percentage of eligible patients with influenza vaccines administered at our group practice during the 2014-15 influenza season. Both outreach methods also solicit patient self-report on influenza vaccinations completed outside the clinic or on barriers to influenza vaccination. Self-reported data from both outreach modes will be uploaded into the EHR to increase accuracy of existing provider-directed EHR CDS (vaccine alerts).
RESULTS: With our proposed sample size and using a factorial design, power calculations using baseline vaccination rate estimates indicated that 4286 participants per arm would give 80% power to detect a 3% improvement in influenza vaccination rates between groups (alpha=.05; 2-sided). Intention-to-treat unadjusted chi-square analyses will be performed to assess the impact of portal messages, either alone or in combination with the IVR call, on influenza vaccination rates. The project was funded in January 2014. Patient enrollment for the project described here completed in December 2014. Data analysis is currently under way and first results are expected to be submitted for publication in 2016.
CONCLUSIONS: If successful, this study\u27s intervention may be adapted by other large health care organizations to increase vaccination rates among their eligible patients.
CLINICALTRIAL: ClinicalTrials.gov NCT02266277; https://clinicaltrials.gov/ct2/show/NCT02266277 (Archived by WebCite at http://www.webcitation.org/6fbLviHLH)
Microbial impacts on 99mTc migration through sandstone under highly alkaline conditions relevant to radioactive waste disposal
Geological disposal of intermediate level radioactive waste in the UK is planned to involve the use of cementitious materials, facilitating the formation of an alkali-disturbed zone within the host rock. The biogeochemical processes that will occur in this environment, and the extent to which they will impact on radionuclide migration, are currently poorly understood. This study investigates the impact of biogeochemical processes on the mobility of the radionuclide technetium, in column experiments designed to be representative of aspects of the alkali-disturbed zone. Results indicate that microbial processes were capable of inhibiting 99mTc migration through columns, and X-ray radiography demonstrated that extensive physical changes had occurred to the material within columns where microbiological activity had been stimulated. The utilisation of organic acids under highly alkaline conditions, generating H2 and CO2, may represent a mechanism by which microbial processes may alter the hydraulic conductivity of a geological environment. Column sediments were dominated by obligately alkaliphilic H2-oxidising bacteria, suggesting that the enrichment of these bacteria may have occurred as a result of H2 generation during organic acid metabolism. The results from these experiments show that microorganisms are able to carry out a number of processes under highly alkaline conditions that could potentially impact on the properties of the host rock surrounding a geological disposal facility for intermediate level radioactive waste
From programme theory to logic models for multispecialty community providers: a realist evidence synthesis
BackgroundThe NHS policy of constructing multispecialty community providers (MCPs) rests on a complex set of assumptions about how health systems can replace hospital use with enhanced primary care for people with complex, chronic or multiple health problems, while contributing savings to health-care budgets.ObjectivesTo use policy-makers’ assumptions to elicit an initial programme theory (IPT) of how MCPs can achieve their outcomes and to compare this with published secondary evidence and revise the programme theory accordingly.DesignRealist synthesis with a three-stage method: (1) for policy documents, elicit the IPT underlying the MCP policy, (2) review and synthesise secondary evidence relevant to those assumptions and (3) compare the programme theory with the secondary evidence and, when necessary, reformulate the programme theory in a more evidence-based way.Data sourcesSystematic searches and data extraction using (1) the Health Management Information Consortium (HMIC) database for policy statements and (2) topically appropriate databases, including MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, PsycINFO, the Cumulative Index to Nursing and Allied Health Literature (CINAHL) and Applied Social Sciences Index and Abstracts (ASSIA). A total of 1319 titles and abstracts were reviewed in two rounds and 116 were selected for full-text data extraction. We extracted data using a formal data extraction tool and synthesised them using a framework reflecting the main policy assumptions.ResultsThe IPT of MCPs contained 28 interconnected context–mechanism–outcome relationships. Few policy statements specified what contexts the policy mechanisms required. We found strong evidence supporting the IPT assumptions concerning organisational culture, interorganisational network management, multidisciplinary teams (MDTs), the uses and effects of health information technology (HIT) in MCP-like settings, planned referral networks, care planning for individual patients and the diversion of patients from inpatient to primary care. The evidence was weaker, or mixed (supporting some of the constituent assumptions but not others), concerning voluntary sector involvement, the effects of preventative care on hospital admissions and patient experience, planned referral networks and demand management systems. The evidence about the effects of referral reductions on costs was equivocal. We found no studies confirming that the development of preventative care would reduce demands on inpatient services. The IPT had overlooked certain mechanisms relevant to MCPs, mostly concerning MDTs and the uses of HITs.LimitationsThe studies reviewed were limited to Organisation for Economic Co-operation and Development countries and, because of the large amount of published material, the period 2014–16, assuming that later studies, especially systematic reviews, already include important earlier findings. No empirical studies of MCPs yet existed.ConclusionsMultidisciplinary teams are a central mechanism by which MCPs (and equivalent networks and organisations) work, provided that the teams include the relevant professions (hence, organisations) and, for care planning, individual patients. Further primary research would be required to test elements of the revised logic model, in particular about (1) how MDTs and enhanced general practice compare and interact, or can be combined, in managing referral networks and (2) under what circumstances diverting patients from in-patient to primary care reduces NHS costs and improves the quality of patient experience.Study registrationThis study is registered as PROSPERO CRD42016038900.FundingThe National Institute for Health Research (NIHR) Health Services and Delivery Research programme and supported by the NIHR Collaboration for Leadership in Applied Health Research and Care South West Peninsula
Preliminary investigation of the influence of dopamine regulating genes on social working memory
Working memory (WM) refers to mental processes that enable temporary retention and manipulation of information, including information about other people (“social working memory”). Previous studies have demonstrated that nonsocial WM is supported by dopamine neurotransmission. Here, we investigated in 131 healthy adults whether dopamine is similarly involved in social WM by testing whether social and nonsocial WM are influenced by genetic variants in three genes coding for molecules regulating the availability of dopamine in the brain: catechol-O-methyltransferase (COMT), dopamine active transporter (DAT), and monoamine-oxidase A (MAOA). An advantage for the Met allele of COMT was observed in the two standard WM tasks and in the social WM task. However, the influence of COMT on social WM performance was not accounted for by its influence on either standard WM paradigms. There was no main effect of DAT1 or MAOA, but a significant COMT x DAT1 interaction on social WM performance. This study provides novel preliminary evidence of effects of genetic variants of the dopamine neurotransmitter system on social cognition. The results further suggest that the effects observed on standard WM do not explain the genetic effects on effortful social cognition
The Relationship between Therapeutic Alliance and Service User Satisfaction in Mental Health Inpatient Wards and Crisis House Alternatives: A Cross-Sectional Study
Background
Poor service user experiences are often reported on mental health inpatient wards. Crisis houses are an alternative, but evidence is limited. This paper investigates therapeutic alliances in acute wards and crisis houses, exploring how far stronger therapeutic alliance may underlie greater client satisfaction in crisis houses.
Methods and Findings
Mixed methods were used. In the quantitative component, 108 crisis house and 247 acute ward service users responded to measures of satisfaction, therapeutic relationships, informal peer support, recovery and negative events experienced during the admission. Linear regressions were conducted to estimate the association between service setting and measures, and to model the factors associated with satisfaction. Qualitative interviews exploring therapeutic alliances were conducted with service users and staff in each setting and analysed thematically.
Results
We found that therapeutic alliances, service user satisfaction and informal peer support were greater in crisis houses than on acute wards, whilst self-rated recovery and numbers of negative events were lower. Adjusted multivariable analyses suggest that therapeutic relationships, informal peer support and negative experiences related to staff may be important factors in accounting for greater satisfaction in crisis houses. Qualitative results suggest factors that influence therapeutic alliances include service user perceptions of basic human qualities such as kindness and empathy in staff and, at service level, the extent of loss of liberty and autonomy.
Conclusions and Implications
We found that service users experience better therapeutic relationships and higher satisfaction in crisis houses compared to acute wards, although we cannot exclude the possibility that differences in service user characteristics contribute to this. This finding provides some support for the expansion of crisis house provision. Further research is needed to investigate why acute ward service users experience a lack of compassion and humanity from ward staff and how this could be changed
Towards quantum enhanced adversarial robustness in machine learning
Machine learning algorithms are powerful tools for data driven tasks such as
image classification and feature detection, however their vulnerability to
adversarial examples - input samples manipulated to fool the algorithm -
remains a serious challenge. The integration of machine learning with quantum
computing has the potential to yield tools offering not only better accuracy
and computational efficiency, but also superior robustness against adversarial
attacks. Indeed, recent work has employed quantum mechanical phenomena to
defend against adversarial attacks, spurring the rapid development of the field
of quantum adversarial machine learning (QAML) and potentially yielding a new
source of quantum advantage. Despite promising early results, there remain
challenges towards building robust real-world QAML tools. In this review we
discuss recent progress in QAML and identify key challenges. We also suggest
future research directions which could determine the route to practicality for
QAML approaches as quantum computing hardware scales up and noise levels are
reduced.Comment: 10 Pages, 4 Figure
Intervention fidelity in the definitive cluster randomised controlled trial of the Healthy Lifestyles Programme (HeLP) trial: findings from the process evaluation.
BACKGROUND: The Healthy Lifestyles Programme (HeLP) was a novel school-located intervention for 9-10Â year olds, designed to prevent obesity by changing patterns of child behaviour through the creation of supportive school and home environments using dynamic and creative delivery methods. This paper reports on both the quantitative and qualitative data regarding the implementation of the HeLP intervention in the definitive cluster randomised controlled trial, which was part of the wider process evaluation. METHODS: Mixed methods were used to collect data on intervention uptake, fidelity of delivery in terms of content and quality of delivery of the intervention, as well as school and child engagement with the programme. Data were collected using registers of attendance, observations and checklists, field notes, focus groups with children and semi-structured interviews with teachers. Qualitative data were analysed thematically and quantitative data were summarized using descriptive statistics. RESULTS: All 16 intervention schools received a complete or near complete programme (94-100%), which was delivered in the spirit in which it had been designed. Of the 676 children in the intervention schools, over 90% of children participated in each phase of HeLP; 92% of children across the socio-economic spectrum were deemed to be engaged with HeLP and qualitative data revealed a high level of enjoyment by all children, particularly to the interactive drama workshops. Further evidence of child engagment with the programme was demonstrated by children's clear understanding of programme messages around marketing, moderation and food labelling. Thirteen of the intervention schools were deemed to be fully engaged with HeLP and qualitative data revealed a high level of teacher 'buy in', due to the programme's compatability with the National Curriculum, level of teacher support and use of innovative and creative delivery methods by external drama practitioners. CONCLUSION: Our trial shows that it is possible to successfully scale up complex school-based interventions, engage schools and children across the socio-economic spectrum and deliver an intervention as designed. As programme integrity was maintained throughout the HeLP trial, across all intervention schools, we can be confident that the trial findings are a true reflection of the effectiveness of the intervention, enabling policy recommendations to be made. TRIAL REGISTRATION: ISRCTN15811706
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