229 research outputs found
A Robust Intelligent Tutoring System for the Integration of People with Intellectual Disabilities into Social and Work Environments
Strong field gravitational lensing in scalar tensor theories
Strong field gravitational lensing in the Brans-Dicke theory has been
studied. The deflection angle for photons passing very close to the photon
sphere is estimated for the static spherically symmetric space-time of the
theory and the position and magnification of the relativistic images are
obtained. Modeling the super massive central object of the galaxy by the
Brans-Dicke space-time, numerical values of different strong lensing observable
are estimated. It is found that against the expectation there is no significant
scalar field effect in the strong field observable lensing parameters. This
observation raises question on the potentiality of the strong field lensing to
discriminate different gravitational theories.Comment: 20 pages, accepted in Class. Quantum Grav., final versio
Influence of atmospheric conditions on the power production of utility-scale wind turbines in yaw misalignment
The intentional yaw misalignment of leading, upwind turbines in a wind farm,
termed wake steering, has demonstrated potential as a collective control
approach for wind farm power maximization. The optimal control strategy, and
resulting effect of wake steering on wind farm power production, are in part
dictated by the power degradation of the upwind yaw misaligned wind turbines.
In the atmospheric boundary layer, the wind speed and direction may vary
significantly over the wind turbine rotor area, depending on atmospheric
conditions and stability, resulting in freestream turbine power production
which is asymmetric as a function of the direction of yaw misalignment and
which varies during the diurnal cycle. In this study, we propose a model for
the power production of a wind turbine in yaw misalignment based on aerodynamic
blade elements which incorporates the effects of wind speed and direction
changes over the turbine rotor area in yaw misalignment. A field experiment is
performed using multiple utility-scale wind turbines to characterize the power
production of yawed freestream operating turbines depending on the wind
conditions, and the model is validated using the experimental data. The
resulting power production of a yaw misaligned variable speed wind turbine
depends on a nonlinear interaction between the yaw misalignment, the
atmospheric conditions, and the wind turbine control system.Comment: 37 pages, 15 figure
Enthalpy and the Mechanics of AdS Black Holes
We present geometric derivations of the Smarr formula for static AdS black
holes and an expanded first law that includes variations in the cosmological
constant. These two results are further related by a scaling argument based on
Euler's theorem. The key new ingredient in the constructions is a two-form
potential for the static Killing field. Surface integrals of the Killing
potential determine the coefficient of the variation of the cosmological
constant in the first law. This coefficient is proportional to a finite,
effective volume for the region outside the AdS black hole horizon, which can
also be interpreted as minus the volume excluded from a spatial slice by the
black hole horizon. This effective volume also contributes to the Smarr
formula. Since the cosmological constant is naturally thought of as a pressure,
the new term in the first law has the form of effective volume times change in
pressure that arises in the variation of the enthalpy in classical
thermodynamics. This and related arguments suggest that the mass of an AdS
black hole should be interpreted as the enthalpy of the spacetime.Comment: 21 pages; v2 references adde
Using Datamining Techniques to Help Metaheuristics: A Short Survey
International audienceHybridizing metaheuristic approaches becomes a common way to improve the efficiency of optimization methods. Many hybridizations deal with the combination of several optimization methods. In this paper we are interested in another type of hybridization, where datamining approaches are combined within an optimization process. Hence, we propose to study the interest of combining metaheuristics and datamining through a short survey that enumerates the different opportunities of such combinations based on literature examples
Potentially inappropriate medication in older participants of the Berlin Aging Study II (BASE-II) - Sex differences and associations with morbidity and medication use
INTRODUCTION:
Multimorbidity in advanced age and the need for drug treatment may lead to polypharmacy, while pharmacokinetic and pharmacodynamic changes may increase the risk of adverse drug events (ADEs).
OBJECTIVE:
The aim of this study was to determine the proportion of subjects using potentially inappropriate medication (PIM) in a cohort of older and predominantly healthy adults in relation to polypharmacy and morbidity.
METHODS:
Cross-sectional data were available from 1,382 study participants (median age 69 years, IQR 67-71, 51.3% females) of the Berlin Aging Study II (BASE-II). PIM was classified according to the EU(7)-PIM and German PRISCUS (representing a subset of the former) list. Polypharmacy was defined as the concomitant use of at least five drugs. A morbidity index (MI) largely based on the Charlson Index was applied to evaluate the morbidity burden.
RESULTS:
Overall, 24.1% of the participants were affected by polypharmacy. On average, men used 2 (IQR 1-4) and women 3 drugs (IQR 1-5). According to PRISCUS and EU(7)-PIM, 5.9% and 22.6% of participants received at least one PIM, while use was significantly more prevalent in females (25.5%) compared to males (19.6%) considering EU(7)-PIM (p = 0.01). In addition, morbidity in males receiving PIM according to EU(7)-PIM was higher (median MI 1, IQR 1-3) compared to males without PIM use (median MI 1, IQR 0-2, p<0.001).
CONCLUSION:
PIM use occurred more frequently in women than in men, while it was associated with higher morbidity in males. As expected, EU(7)-PIM identifies more subjects as PIM users than the PRISCUS list but further studies are needed to investigate the differential impact of both lists on ADEs and outcome.
KEY POINTS:
We found PIM use to be associated with a higher number of regular medications and with increased morbidity. Additionally, we detected a higher prevalence of PIM use in females compared to males, suggesting that women and people needing intensive drug treatment are patient groups, who are particularly affected by PIM use
C3-Cloud personalised care plan development platform for addressing the needs of multi-morbidity and managing poly-pharmacy : protocol for a pilot technology trial
Background:
There is an increasing need to organise the care around the patient and not the disease, as well as taking into account the complex realities of multiple physical, psycho-social conditions and polypharmacy. Integrated patient-centred care delivery platforms have been developed for both patients and clinicians. These platforms could provide a promising way to achieve a collaborative environment that improves the provision of integrated care for patients via enhanced ICT solutions.
Objective:
The C3-Cloud project has developed two collaborative computer platforms for patients and members of the Multi-Disciplinary Team and deployed these in three different European settings. The objective of this study is to pilot test the platforms and evaluate their impact on patients, informal caregivers, healthcare professionals and, in extend, healthcare systems.
Methods:
This paper describes the protocol for conducting an evaluation of the user-centred design, user experience, acceptability, and usefulness of the platforms. For this, four ‘testing and evaluation’ phases have been defined, involving multiple qualitative methods, and advanced impact modelling.
Results:
The technology trial in this 4-year funded project (2016-2020) is currently in its execution phase. The testing and evaluation phase 1 and 2 have been completed with satisfying results on system component tests, and promising results on application and usability tests. The pilot technology trial for evaluation phase 3 and 4 was launched in August 2019. Data collection for these phases is underway and results are forthcoming, approximately in April 2020. We believe that the phased, iterative approach taken is useful as it involves relevant stakeholders at crucial stages in the platform development and allows for a sound user acceptance assessment of the final product.
Conclusions:
Patients with multiple chronic conditions often experience shortcomings in the care they receive. It is hoped that personalised care plan platforms for patients and collaboration platforms for members of Multi-Disciplinary Teams can help to tackle the specific challenges of clinical guideline reconciliation for multimorbid patients and improved the management of poly-pharmacy. The initial evaluative phases have indicated promising results of platform usability. The phased methodology has shown useful results in the first two phases, while results of phase 3 and 4 are pending. Clinical Trial: https://www.clinicaltrials.gov/ct2/show/NCT0383420
Laboratory Diagnosis of SARS
The virologic test results of 415 patients with severe acute respiratory syndrome (SARS) were examined. The peak detection rate for SARS-associated coronavirus occurred at week 2 after illness onset for respiratory specimens, at weeks 2 to 3 for stool or rectal swab specimens, and at week 4 for urine specimens. The latest stool sample that was positive by reverse transcription–polymerase chain reaction (RT-PCR) was collected on day 75 while the patient was receiving intensive care. Tracheal aspirate and stool samples had a higher diagnostic yield (RT-PCR average positive rate for first 2 weeks: 66.7% and 56.5%, respectively). Pooled throat and nasal swabs, rectal swab, nasal swab, throat swab, and nasopharyngeal aspirate specimens provided a moderate yield (29.7%–40.0%), whereas throat washing and urine specimens showed a lower yield (17.3% and 4.5%). The collection procedures for stool and pooled nasal and throat swab specimens were the least likely to transmit infection, and the combination gave the highest yield for coronavirus detection by RT-PCR. Positive virologic test results in patient groups were associated with mechanical ventilation or death (p < 0.001), suggesting a correlation between viral load and disease severity
Treatment challenges in and outside a specialist network setting: Pancreatic neuroendocrine tumours
Pancreatic Neuroendocrine Neoplasms comprise a group of rare tumours with special biology, an often indolent behaviour and particular diagnostic and therapeutic requirements. The specialized biochemical tests and radiological investigations, the complexity of surgical options and the variety of medical treatments that require individual tailoring, mandate a multidisciplinary approach that can be optimally achieved through an organized network. The present study describes currents concepts in the management of these tumours as well as an insight into the challenges of delivering the pathway in and outside a Network
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