224 research outputs found
Distributed Estimation with Information-Seeking Control in Agent Network
We introduce a distributed, cooperative framework and method for Bayesian
estimation and control in decentralized agent networks. Our framework combines
joint estimation of time-varying global and local states with
information-seeking control optimizing the behavior of the agents. It is suited
to nonlinear and non-Gaussian problems and, in particular, to location-aware
networks. For cooperative estimation, a combination of belief propagation
message passing and consensus is used. For cooperative control, the negative
posterior joint entropy of all states is maximized via a gradient ascent. The
estimation layer provides the control layer with probabilistic information in
the form of sample representations of probability distributions. Simulation
results demonstrate intelligent behavior of the agents and excellent estimation
performance for a simultaneous self-localization and target tracking problem.
In a cooperative localization scenario with only one anchor, mobile agents can
localize themselves after a short time with an accuracy that is higher than the
accuracy of the performed distance measurements.Comment: 17 pages, 10 figure
Cooperative Simultaneous Localization and Synchronization in Mobile Agent Networks
Cooperative localization in agent networks based on interagent time-of-flight
measurements is closely related to synchronization. To leverage this relation,
we propose a Bayesian factor graph framework for cooperative simultaneous
localization and synchronization (CoSLAS). This framework is suited to mobile
agents and time-varying local clock parameters. Building on the CoSLAS factor
graph, we develop a distributed (decentralized) belief propagation algorithm
for CoSLAS in the practically important case of an affine clock model and
asymmetric time stamping. Our algorithm allows for real-time operation and is
suitable for a time-varying network connectivity. To achieve high accuracy at
reduced complexity and communication cost, the algorithm combines particle
implementations with parametric message representations and takes advantage of
a conditional independence property. Simulation results demonstrate the good
performance of the proposed algorithm in a challenging scenario with
time-varying network connectivity.Comment: 13 pages, 6 figures, 3 tables; manuscript submitted to IEEE
Transaction on Signal Processin
Cooperative localization with information-seeking control
We propose a Bayesian method for cooperative localization and control in mobile agent networks. Distributed, cooperative self-localization of each agent is supported by an information-seeking control of the movement of the agents. For cooperative localization, the SPAWN message passing scheme is used. Cooperative control is achieved by maximizing the negative joint posterior entropy of the agent states via a gradient ascent. The localization part of our method provides the control part with sample-based probabilistic information. Simulation results demonstrate intelligent behavior of the agents and excellent localization accuracy
An Intervention Program to Reduce Medication-Related Problems Among Polymedicated Home-Dwelling Older Adults (OptiMed): Protocol for a Pre-Post, Multisite, Pilot, and Feasibility Study.
BACKGROUND
Effective medication management is one of the essential preconditions for enabling polymedicated home-dwelling older adults with multiple chronic conditions to remain at home and preserve their quality of life and autonomy. Lack of effective medication management predisposes older adults to medication-related problems (MRPs) and adverse health outcomes, which can lead to the degradation of a patient's acute clinical condition, physical and cognitive decline, exacerbation of chronic medical conditions, and avoidable health care costs. Nonetheless, it has been shown that MRPs can be prevented or reduced by using well-coordinated, patient-centered, interprofessional primary care interventions.
OBJECTIVE
This study aimed to explore the feasibility and acceptability of an evidence-based, multicomponent, interprofessional intervention program supported by informal caregivers to decrease MRPs among polymedicated home-dwelling older adults with multiple chronic conditions.
METHODS
This quasi-experimental, pre-post, multisite pilot, and feasibility study will use an open-label design, with participants knowing the study's objectives and relevant information, and it will take place in primary health care settings in Portugal and Switzerland. The research population will comprise 30 polymedicated, home-dwelling adults, aged ≥65 years at risk of MRPs and receiving community-based health care, along with their informal caregivers and health care professionals.
RESULTS
Before a projected full-scale study, this pilot and feasibility study will focus on recruiting and ensuring the active collaboration of its participants and on the feasibility of expanding this evidence-based, multicomponent, interprofessional intervention program throughout both study regions. This study will also be essential to projected follow-up research programs on informal caregivers' multiple roles, enhancing their coordination tasks and their own needs. Results are expected at the end of 2024.
CONCLUSIONS
Designing, establishing, and exploring the feasibility and acceptability of an intervention program to reduce the risks of MRPs among home-dwelling older adults is an underinvestigated issue. Doing so in collaboration with all the different actors involved in that population's medication management and recording the first effects of the intervention will make this pilot and feasibility study's findings very valuable as home care becomes an ever more common solution.
TRIAL REGISTRATION
Swiss National Clinical Trials Portal 000004654; https://tinyurl.com/mr3yz8t4
A counterion study of a series of [Cu(P^P)(N^N)][A] compounds with bis(phosphane) and 6-methyl and 6,6'-dimethyl-substituted 2,2'-bipyridine ligands for light-emitting electrochemical cells
The syntheses and characterisations of a series of heteroleptic copper(i) compounds [Cu(POP)(Mebpy)][A], [Cu(POP)(Me(2)bpy)][A], [Cu(xantphos)(Mebpy)][A] and [Cu(xantphos)(Me(2)bpy)][A] in which [A](-) is [BF4](-), [PF6](-), [BPh4](-) and [BAr4F](-) (Mebpy = 6-methyl-2,2 '-bipyridine, Me(2)bpy = 6,6 '-dimethyl-2,2 '-bipyridine, POP = oxydi(2,1-phenylene)bis(diphenylphosphane), xantphos = (9,9-dimethyl-9H-xanthene-4,5-diyl)bis(diphenylphosphane), [BAr4F](-) = tetrakis(3,5-bis(trifluoromethyl)phenyl)borate) are reported. Nine of the compounds have been characterised by single crystal X-ray crystallography, and the consequences of the different anions on the packing interactions in the solid state are discussed. The effects of the counterion on the photophysical properties of [Cu(POP)(NN)][A] and [Cu(xantphos)(NN)][A] (NN = Mebpy and Me(2)bpy) have been investigated. In the solid-state emission spectra, the highest energy emission maxima are for [Cu(xantphos)(Mebpy)][BPh4] and [Cu(xantphos)(Me(2)bpy)][BPh4] (lambda emmax = 520 nm) whereas the lowest energy lambda emmax values occur for [Cu(POP)(Mebpy)][PF6] and [Cu(POP)(Mebpy)][BPh4] (565 nm and 563 nm, respectively). Photoluminescence quantum yields (PLQYs) are noticeably affected by the counterion; in the [Cu(xantphos)(Me(2)bpy)][A] series, solid-state PLQY values decrease from 62% for [PF6](-), to 44%, 35% and 27% for [BF4](-), [BPh4](-) and [BAr4F](-), respectively. This latter series of compounds was used as active electroluminescent materials on light-emitting electrochemical cells (LECs). The luminophores were mixed with ionic liquids (ILs) [EMIM][A] ([EMIM](+) = [1-ethyl-3-methylimidazolium](+)) containing the same or different counterions than the copper(i) complex. LECs containing [Cu(xantphos)(Me(2)bpy)][BPh4] and [Cu(xantphos)(Me(2)bpy)][BAr4F] failed to turn on under the LEC operating conditions, whereas those with the smaller [PF6](-) or [BF4](-) counterions had rapid turn-on times and exhibited maximum luminances of 173 and 137 cd m(-2) and current efficiencies of 3.5 and 2.6 cd A(-1), respectively, when the IL contained the same counterion as the luminophore. Mixing the counterions ([PF6](-) and [BF4](-)) of the active complex and the IL led to a reduction in all the figures of merit of the LECs
Unplanned nursing home admission among discharged polymedicated older inpatients: a single-centre, registry-based study in Switzerland.
OBJECTIVE
To investigate patient characteristics and the available health and drug data associated with unplanned nursing home admission following an acute hospital admission or readmission.
DESIGN
A population-based hospital registry study.
SETTING
A public hospital in southern Switzerland (Valais Hospital).
PARTICIPANTS
We explored a population-based longitudinal dataset of 14 705 hospital admissions from 2015 to 2018.
OUTCOME MEASURES
Sociodemographic, health and drug data, and their interactions predicting the risk of unplanned nursing home admission.
RESULTS
The mean prevalence of unplanned nursing home admission after hospital discharge was 6.1% (n=903/N=14 705). Our predictive analysis revealed that the oldest adults (OR=1.07 for each additional year of age; 95% CI 1.05 to 1.08) presenting with impaired functional mobility (OR=3.22; 95% CI 2.67 to 3.87), dependency in the activities of daily living (OR=4.62; 95% CI 3.76 to 5.67), cognitive impairment (OR=3.75; 95% CI 3.06 to 4.59) and traumatic injuries (OR=1.58; 95% CI 1.25 to 2.01) had a higher probability of unplanned nursing home admission. The number of International Classification of Diseases, 10th version diagnoses had no significant impact on nursing home admissions, contrarily to the number of prescribed drugs (OR=1.17; 95% CI 1.15 to 1.19). Antiemetics/antinauseants (OR=2.53; 95% CI 1.21 to 5.30), digestives (OR=1.78; 95% CI 1.09 to 2.90), psycholeptics (OR=1.76; 95% CI 1.60 to 1.93), antiepileptics (OR=1.49; 95% CI 1.25 to 1.79) and anti-Parkinson's drugs (OR=1.40; 95% CI 1.12 to 1.75) were strongly linked to unplanned nursing home admission.
CONCLUSIONS
Numerous risk factors for unplanned nursing home admission were identified. To prevent the adverse health outcomes that precipitate acute hospitalisations and unplanned nursing home admissions, ambulatory care providers should consider these risk factors in their care planning for older adults before they reach a state requiring hospitalisation
Prenatal smoke exposure induces persistent Cyp2a5 methylation and increases nicotine metabolism in the liver of neonatal and adult male offspring
Prenatal smoke exposure (PSE) is a risk factor for nicotine dependence. One susceptibility gene for nicotine dependence is Cytochrome P450 (CYP) 2A6, an enzyme responsible for the conversion of nicotine to cotinine and nicotine clearance in the liver. Higher activity of the CYP2A6 enzyme is associated with nicotine dependence, but no research has addressed the PSE effects on the CYP2A6 gene or its mouse homologue Cyp2a5. We hypothesized that PSE affects Cyp2a5 promoter methylation, Cyp2a5 mRNA levels, and nicotine metabolism in offspring. We used a smoke-exposed pregnant mouse model. RNA, DNA, and microsomal protein were isolated from liver tissue of foetal, neonatal, and adult offspring. Enzyme activity, Cyp2a5 mRNA levels, and Cyp2a5 methylation status of six CpG sites within the promoter region were analysed via HPLC, RT-PCR, and bisulphite pyrosequencing. Our data show that PSE induced higher cotinine levels in livers of male neonatal and adult offspring compared to controls. PSE-induced cotinine levels in neonates correlated with Cyp2a5 mRNA expression and promoter methylation at CpG-7 and CpG+45. PSE increased methylation in almost all CpG sites in foetal offspring, and this effect persisted at CpG-74 in male neonatal and adult offspring. Our results indicate that male offspring of mothers which were exposed to cigarette smoke during pregnancy have a higher hepatic nicotine metabolism, which could be regulated by DNA methylation. Given the detected persistence into adulthood, extrapolation to the human situation suggests that sons born from smoking mothers could be more susceptible to nicotine dependence later in life
Postnatal Smoke Exposure Further Increases the Hepatic Nicotine Metabolism in Prenatally Smoke Exposed Male Offspring and Is Linked with Aberrant Cyp2a5 Methylation
Prenatal smoke exposure (PreSE) is a risk factor for nicotine dependence, which is further enhanced by postnatal smoke exposure (PostSE). One susceptibility gene to nicotine dependence is Cytochrome P450 (CYP) 2A6, an enzyme responsible for the conversion of nicotine to cotinine in the liver. Higher CYP2A6 activity is associated with nicotine dependence and could be regulated through DNA methylation. In this study we investigated whether PostSE further impaired PreSE-induced effects on nicotine metabolism, along with Cyp2a5, orthologue of CYP2A6, mRNA expression and DNA methylation. Using a mouse model where prenatally smoke-exposed adult offspring were exposed to cigarette smoke for 3 months, enzyme activity, mRNA levels, and promoter methylation of hepatic Cyp2a5 were evaluated. We found that in male offspring, PostSE increased PreSE-induced cotinine levels and Cyp2a5 mRNA expression. In addition, both PostSE and PreSE changed Cyp2a5 DNA methylation in male groups. PreSE however decreased cotinine levels whereas it had no effect on Cyp2a5 mRNA expression or methylation. These adverse outcomes of PreSE and PostSE were most prominent in males. When considered in the context of the human health aspects, the combined effect of prenatal and adolescent smoke exposure could lead to an accelerated risk for nicotine dependence later in life.</p
Comparison of LDL fatty acid and carotenoid concentrations and oxidative resistance of LDL in volunteers from countries with different rates of cardiovascular disease
Within Europe there are differences in cardiovascular disease (CVD) risk between countries and this might be related to dietary habits. Oxidative modification of LDL is suggested to increase the risk of CVD and both the fatty acid and antioxidant content of LDL can affect its oxidation. In the present study, concentration of LDL fatty acid and antioxidant micronutrients (tocopherols and carotenoids) and ex vivo oxidative resistance of LDL (lag phase) was compared in volunteers from five countries with different fruit and vegetable intakes and reported rates of CVD. Eighty volunteers (forty males, forty females per centre), age range 25-45 years, were recruited from France, Northern Ireland, UK, Republic of Ireland, The Netherlands, and Spain, and their LDL composition and lag phase were measured. There were some differences in LDL carotenoid and α-tocopherol concentrations between countries. α-Tocopherol was low and β- + γ-tocopherol were high (P<0·001) in the Dutch subjects. β-Carotene concentrations were significantly different between the French and Spanish volunteers, with French showing the highest and Spanish the lowest concentration. LDL lycopene was not different between centres in contrast to lutein, which was highest in French (twofold that in the Dutch and Spanish and threefold that in Northern Ireland and the Republic of Ireland, P<0·001). However absolute LDL saturated, monounsaturated, polyunsaturated and total unsaturated fatty acid concentrations were different between countries (P<0·001, total unsaturated highest in Northern Ireland) there was little difference in unsaturated:saturated fatty acid concentration ratios and no difference in polyunsaturated:saturated fatty acid concentration ratios. LDL from the Republic of Ireland (a region with a high rate of CVD) had greater resistance to Cu-stimulated oxidation than samples obtained from volunteers in other countries. In conclusion, LDL composition did not predict resistance to Cu-stimulated oxidation, nor is there evidence that LDL from volunteers in countries with lower rates of CVD have greater resistance to oxidatio
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