1,362 research outputs found
Parameter-Independent Strategies for pMDPs via POMDPs
Markov Decision Processes (MDPs) are a popular class of models suitable for
solving control decision problems in probabilistic reactive systems. We
consider parametric MDPs (pMDPs) that include parameters in some of the
transition probabilities to account for stochastic uncertainties of the
environment such as noise or input disturbances.
We study pMDPs with reachability objectives where the parameter values are
unknown and impossible to measure directly during execution, but there is a
probability distribution known over the parameter values. We study for the
first time computing parameter-independent strategies that are expectation
optimal, i.e., optimize the expected reachability probability under the
probability distribution over the parameters. We present an encoding of our
problem to partially observable MDPs (POMDPs), i.e., a reduction of our problem
to computing optimal strategies in POMDPs.
We evaluate our method experimentally on several benchmarks: a motivating
(repeated) learner model; a series of benchmarks of varying configurations of a
robot moving on a grid; and a consensus protocol.Comment: Extended version of a QEST 2018 pape
Detecting temporal and spatial effects of epithelial cancers with Raman spectroscopy.
PublishedJournal ArticleResearch Support, N.I.H., ExtramuralResearch Support, Non-U.S. Gov'tThis is the final version of the article. Available from Hindawi Publishing Corporation via the DOI in this record.Epithelial cancers, including those of the skin and cervix, are the most common type of cancers in humans. Many recent studies have attempted to use Raman spectroscopy to diagnose these cancers. In this paper, Raman spectral markers related to the temporal and spatial effects of cervical and skin cancers are examined through four separate but related studies. Results from a clinical cervix study show that previous disease has a significant effect on the Raman signatures of the cervix, which allow for near 100% classification for discriminating previous disease versus a true normal. A Raman microspectroscopy study showed that Raman can detect changes due to adjacent regions of dysplasia or HPV that cannot be detected histologically, while a clinical skin study showed that Raman spectra may be detecting malignancy associated changes in tissues surrounding nonmelanoma skin cancers. Finally, results of an organotypic raft culture study provided support for both the skin and the in vitro cervix results. These studies add to the growing body of evidence that optical spectroscopy, in this case Raman spectral markers, can be used to detect subtle temporal and spatial effects in tissue near cancerous sites that go otherwise undetected by conventional histology.The authors acknowledge the financial support of the
NCI/NIH (R01-CA95405 and R21-CA95995), as well
as the Howard Hughes Medical Institute (pre-doctoral
fellowship for MK). We would also like to thank the
doctors and staff at Vanderbilt University Medical Center
and Tri-state Womenâs Health for all their assistance
The role of external broadcasting in a closed political system
This article investigates the role and impact of external broadcasting (radio and television) on a closed political system, through the example of the two post-war German states: the West German Federal Republic of Germany (FRG) and the East German German Democratic Republic (GDR). The aim is to debunk myths about the influence of external broadcasting on the events that led to German reunification in 1990. The study follows a historical approach and discusses what role external media played during the years of a divided Germany. The findings are based on several historical sources, research reports from the 1950s and 1960s and over 100 biographical interviews with former residents of the German Democratic Republic (GDR). The article analyses the impact of external broadcasting on citizens and the political elite in times of crisis as well as during everyday life
Bounded Model Checking for Probabilistic Programs
In this paper we investigate the applicability of standard model checking
approaches to verifying properties in probabilistic programming. As the
operational model for a standard probabilistic program is a potentially
infinite parametric Markov decision process, no direct adaption of existing
techniques is possible. Therefore, we propose an on-the-fly approach where the
operational model is successively created and verified via a step-wise
execution of the program. This approach enables to take key features of many
probabilistic programs into account: nondeterminism and conditioning. We
discuss the restrictions and demonstrate the scalability on several benchmarks
Add-On Cannabidiol Treatment for Drug-Resistant Seizures in Tuberous Sclerosis Complex A Placebo-Controlled Randomized Clinical Trial
IMPORTANCE Efficacy of cannabidiol has been demonstrated in seizures associated with
Lennox-Gastaut and Dravet syndromes but appears not yet to have been established in
conditions with primarily focal seizures, such as tuberous sclerosis complex (TSC).
OBJECTIVE To evaluate efficacy and safety of 25-mg/kg/day and 50-mg/kg/day cannabidiol
dosages vs placebo against seizures associated with TSC.
DESIGN, SETTING, AND PARTICIPANTS This double-blind, placebo-controlled randomized
clinical trial (GWPCARE6) enrolled patients between April 6, 2016, and October 4, 2018;
follow-up was completed on February 15, 2019. The trial was conducted at 46 sites in
Australia, Poland, Spain, the Netherlands, United Kingdom, and United States. Eligible
patients (aged 1-65 years) were those with a clinical diagnosis of TSC and medicationresistant
epilepsy who had had at least 8 TSC-associated seizures during the 4-week baseline
period, with at least 1 seizure occurring in at least 3 of the 4 weeks, and were currently taking
at least 1 antiepileptic medication.
INTERVENTIONS Patients received oral cannabidiol at 25mg/kg/day (CBD25) or 50
mg/kg/day (CBD50) or a matched placebo for 16 weeks.
MAIN OUTCOMES AND MEASURES The prespecified primary outcomewas the change from
baseline in number of TSC-associated seizures for cannabidiol vs placebo during the
treatment period.
RESULTS Of 255 patients screened for eligibility, 31 were excluded and 224 were randomized.
Of the 224 included patients (median [range] age, 11.4 [1.1-56.8] years; 93 female patients
[41.5%]), 75 were randomized to CBD25, 73 to CBD50, and 76 to placebo, with 201
completing treatment. The percentage reduction from baseline in the type of seizures
considered the primary end point was 48.6%(95%CI, 40.4%-55.8%) for the CBD25 group,
47.5%(95%CI, 39.0%-54.8%) for the CBD50 group, and 26.5%(95%CI, 14.9%-36.5%) for
the placebo group; the percentage reduction from placebo was 30.1% (95%CI, 13.9%-43.3%;
P < .001) for the CBD25 group and 28.5%(95%CI, 11.9%-42.0%; nominal P = .002) for the
CBD50 group. The most common adverse events were diarrhea (placebo group, 19 [25%];
CBD25 group, 23 [31%]; CBD50 group, 41 [56%]) and somnolence (placebo group, 7 [9%];
CBD25 group, 10 [13%]; CBD50 group, 19 [26%]), which occurred more frequently with
cannabidiol than placebo. Eight patients in CBD25 group, 10 in CBD50 group, and 2 in the
placebo group discontinued treatment because of adverse events. Twenty-eight patients
taking cannabidiol (18.9%) had elevated liver transaminase levels vs none taking placebo.
CONCLUSIONS AND RELEVANCE Cannabidiol significantly reduced TSC-associated seizures
compared with placebo. The 25-mg/kg/day dosage had a better safety profile than the
50-mg/kg/day dosage.
TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0254476
Post-streptococcal reactive arthritis in children: a distinct entity from acute rheumatic fever
There is a debate whether post-streptococcal reactive arthritis (PSRA) is a separate entity or a condition on the spectrum of acute rheumatic fever (ARF). We believe that PSRA is a distinct entity and in this paper we review the substantial differences between PSRA and ARF. We show how the demographic, clinical, genetic and treatment characteristics of PSRA differ from ARF. We review diagnostic criteria and regression formulas that attempt to classify patients with PSRA as opposed to ARF. The important implication of these findings may relate to the issue of prophylactic antibiotics after PSRA. However, future trials will be necessary to conclusively answer that question
Trans-eQTLs Reveal That Independent Genetic Variants Associated with a Complex Phenotype Converge on Intermediate Genes, with a Major Role for the HLA
This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Communication in production animal medicine: modelling a complex interaction with the example of dairy herd health medicine
<p>Abstract</p> <p>Background</p> <p>The importance of communication skills in veterinary medicine is increasingly recognised. Appropriate communication skills towards the client are of utmost importance in both companion animal practice and production animal field and consultancy work. The need for building a relationship with the client, alongside developing a structure for the consultation is widely recognised and applies to both types of veterinary practice.</p> <p>Results</p> <p>Veterinary advisory practice in production animal medicine is, however, characterised by a more complex communication on different levels. While the person-orientated communication is a permanent process between veterinarian and client with a rather personal perspective and defines the roles of interaction, the problem-orientated communication deals with emerging difficulties; the objective is to solve an acute health problem. The solution - orientated communication is a form of communication in which both veterinarian and client address longstanding situations or problems with the objective to improve herd health and subsequently productivity performance. All three forms of communication overlap.</p> <p>Conclusions</p> <p>Based on this model, it appears useful for a veterinary practice to offer both a curative and an advisory service, but to keep these two separated when deemed appropriate. In veterinary education, the strategies and techniques necessary for solution orientated communication should be included in the teaching of communication skills.</p
Need for recovery from work in relation to age: a prospective cohort study
To investigate the impact of increasing age on the need for recovery (NFR) over time among day workers The study is based on data from the first 2 years of follow-up of the Maastricht Cohort Study (n = 7,734). To investigate whether age predicted the onset of elevated NFR, multivariate survival analyses were conducted The highest levels of NFR were observed in the age group of 46-55 years. The relative risk for developing elevated NFR was highest in the age groups 36-45 years (RR 1.30; 1.07-1.58) and 46-55 years (RR 1.25; 1.03-1.52) in men and 46-55 years (RR 1.36; 1.04-1.77) in women when compared to the reference group While NFR increased with age until the age of 55, this was followed by decreased levels of NFR among older employees. Explanations for the decreasing levels of NFR in the highest age group can be found in several domains such as the work environment, private situation and compensation strategies
- âŚ