2,178 research outputs found
Understanding the lived experiences of Mexican informal caregivers with Ambient Assisted Living Technologies
Ambient Assisted Living (AAL) Technologies, have the potential to support the people with dementia living in their homes for longer. Dementia is a major public health concern. It currently affects approximately 46.8 million people worldwide and by 2050 this figure will increase to 131.5 million. Low-and-middle income countries (LMIC) will be particularly affected by this situation as their poor health infrastructures and governmental support will mean that they have to rely on the informal caregiver (IC) sector. ICs are people who care for a dependent or disabled family member, commonly spouses or daughters. Mexico was the first Spanish speaking country in the world to recognise dementia as a public health priority. In-home technologies, such as AAL Technologies, are used in dementia care in order to improve patients’ and caregivers’ quality of life. This paper explores the way in which Mexican ICs of people with dementia (PWD) make sense of their lived experiences with AAL technologies
Value signals guide abstraction during learning
The human brain excels at constructing and using abstractions, such as rules, or concepts. Here, in two fMRI experiments, we demonstrate a mechanism of abstraction built upon the valuation of sensory features. Human volunteers learned novel association rules based on simple visual features. Reinforcement-learning algorithms revealed that, with learning, high-value abstract representations increasingly guided participant behaviour, resulting in better choices and higher subjective confidence. We also found that the brain area computing value signals – the ventromedial prefrontal cortex – prioritised and selected latent task elements during abstraction, both locally and through its connection to the visual cortex. Such a coding scheme predicts a causal role for valuation. Hence, in a second experiment, we used multivoxel neural reinforcement to test for the causality of feature valuation in the sensory cortex, as a mechanism of abstraction. Tagging the neural representation of a task feature with rewards evoked abstraction-based decisions. Together, these findings provide a novel interpretation of value as a goal-dependent, key factor in forging abstract representations
Accuracy of Trace Formulas
Using quantum maps we study the accuracy of semiclassical trace formulas. The
role of chaos in improving the semiclassical accuracy, in some systems, is
demonstrated quantitatively. However, our study of the standard map cautions
that this may not be most general. While studying a sawtooth map we demonstrate
the rather remarkable fact that at the level of the time one trace even in the
presence of fixed points on singularities the trace formula may be exact, and
in any case has no logarithmic divergences observed for the quantum bakers map.
As a byproduct we introduce fantastic periodic curves akin to curlicues.Comment: 20 pages, uuencoded and gzipped, 1 LaTex text file and 9 PS files for
figure
Quantum dissipation due to the interaction with chaotic degrees-of-freedom and the correspondence principle
Both in atomic physics and in mesoscopic physics it is sometimes interesting
to consider the energy time-dependence of a parametrically-driven chaotic
system. We assume an Hamiltonian where . The
velocity is slow in the classical sense but not necessarily in the
quantum-mechanical sense. The crossover (in time) from ballistic to diffusive
energy-spreading is studied. The associated irreversible growth of the average
energy has the meaning of dissipation. It is found that a dimensionless
velocity determines the nature of the dynamics, and controls the route
towards quantal-classical correspondence (QCC). A perturbative regime and a
non-perturbative semiclassical regime are distinguished.Comment: 4 pages, clear presentation of the main poin
Surface plasmon resonance biosensors for highly sensitive detection in real samples
In this work we summarize the main results obtained with the portable surface plasmon resonance (SPR) device developed in our group (commercialised by SENSIA, SL, Spain), highlighting its applicability for the real-time detection of extremely low concentrations of toxic pesticides in environmental water samples. In addition, we show applications in clinical diagnosis as, on the one hand, the real-time and label-free detection of DNA hybridization and single point mutations at the gene BRCA-1, related to the predisposition in women to develop an inherited breast cancer and, on the other hand, the analysis of protein biomarkers in biological samples (urine, serum) for early detection of diseases. Despite the large number of applications already proven, the SPR technology has two main drawbacks: (i) not enough sensitivity for some specific applications (where pM-fM or single-molecule detection are needed) (ii) low multiplexing capabilities. In order solve such drawbacks, we work in several alternative configurations as the Magneto-optical Surface Plasmon Resonance sensor (MOSPR) based on a combination of magnetooptical and ferromagnetic materials, to improve the SPR sensitivity, or the Localized Surface Plasmon Resonance (LSPR) based on nanostructures (nanoparticles, nanoholes,...), for higher multiplexing capabilities
Variations of the Vocal Fold Epithelium in a Menopause Induced Model
During menopause, changes occur in the laryngeal structures that have implications for the voice. The purpose of this study was to determine the effect of induced menopause on the morphological parameters of the vocal fold mucosa in rats. Ten adult female Sprague-Dawley rats were used as samples and divided into two groups: 5 were surgically oophorectomized (OVX), and 5 underwent a surgical procedure similar to oophorectomy but without removal of the ovaries (SHAM). After 30 days surgery, the characteristics of the epithelium that forms the vocal fold mucosa in terms of cellular arrangement and organization of the epithelium were observed. Through the Morphometrics XS software, the epithelial height and the number and density of cellular layers were determined. Our results indicate that there were alterations in the number of cell layers that constitute the epithelium, as well as features, such as cellular cohesion and increased extracellular matrix. The number of cell layers was significantly higher (p<0.01) in the SHAM group with 6.66 (SD 1.07), whereas in the OVX was 3.2 (SD 0.83). The average thickness of the epithelium was 534.71 mm (SD 119.89), whereas in the SHAM group was 486.84 mm (SD 82.95); these differences were not statistically significant (p = 0.112). Changes in the characteristics of the epithelium covering the vocal folds can be related to clinical abnormalities, such as reduced voice quality and degeneration of the vocal folds in postmenopausal women
Prevention, screening and treatment of colorectal cancer: a global and regional generalized cost effectiveness analysis
<p>Abstract</p> <p>Background</p> <p>Regional generalized cost-effectiveness estimates of prevention, screening and treatment interventions for colorectal cancer are presented.</p> <p>Methods</p> <p>Standardised WHO-CHOICE methodology was used. A colorectal cancer model was employed to provide estimates of screening and treatment effectiveness. Intervention effectiveness was determined via a population state-transition model (PopMod) that simulates the evolution of a sub-regional population accounting for births, deaths and disease epidemiology. Economic costs of procedures and treatment were estimated, including programme overhead and training costs.</p> <p>Results</p> <p>In regions characterised by high income, low mortality and high existing treatment coverage, the addition of screening to the current high treatment levels is very cost-effective, although no particular intervention stands out in cost-effectiveness terms relative to the others.</p> <p>In regions characterised by low income, low mortality with existing treatment coverage around 50%, expanding treatment with or without screening is cost-effective or very cost-effective. Abandoning treatment in favour of screening (no treatment scenario) would not be cost effective.</p> <p>In regions characterised by low income, high mortality and low treatment levels, the most cost-effective intervention is expanding treatment.</p> <p>Conclusions</p> <p>From a cost-effectiveness standpoint, screening programmes should be expanded in developed regions and treatment programmes should be established for colorectal cancer in regions with low treatment coverage.</p
Weight gain and dietary intake during pregnancy in industrialized countries - a systematic review of observational studies
Background: Gestational weight gain (GWG) above the recently recommended ranges is likely to be related to adverse pregnancy outcomes and therefore a challenge in industrialized countries. Aims: We conducted a systematic review on observational studies in order to gain more evidence on whether diets with lower caloric/protein content or other diets might be associated with lower GWG. Methods: We searched in MEDLINE and EMBASE for observational studies written in English or German reporting associations between diet and GWG in singleton pregnancies of healthy women in industrialized countries. Results: We identified 12 studies which met the inclusion criteria. Five studies suggested significant positive associations between energy intake and GWG, whereas three found no significant association. Further significant positive associations of GWG were reported with respect to protein intake, animal lipids, energy density and a number of different food servings per day, whereas intake of carbohydrates and vegetarian diet were associated with less GWG. Conclusions: We suggest that GWG might be reduced by lower energy intake in pregnancy
Comparison of therapeutic triiodothyronine versus metoprolol in the treatment of myocardial infarction in rats
© 2018 Mary Ann Liebert, Inc. Background: Beta blockers are standard therapy for myocardial infarction (MI). Preclinical studies have shown efficacy and safety of thyroid hormone (TH) treatment of cardiovascular disorders. Since THs interact with the sympathoadrenergic system, this study aimed to compare triiodothyronine (T3) and metoprolol (Met) in the treatment of rats with MI on pathophysiology and TH-adrenergic signaling. Methods: Female Sprague-Dawley rats aged 12 weeks underwent left anterior descending coronary artery ligation (MI) or sham surgeries. T3 (5 μg/kg/day) or Met (100 mg/kg/day) was given in drinking water immediately after surgery for eight weeks. At the terminal of the experiments, the rats were subjected to morphological, functional, and molecular examination. Results: T3 and Met significantly enhanced left ventricular contractility (left ventricular fractional shortening 21.37 ± 2.58% and 21.14 ± 3.71%, respectively) compared to untreated MI (17.88 ± 1.23%), and decreased the incidence of inducible atrial tachyarrhythmia by 87.5% and 62.5%, respectively. Although both treatments showed efficacy, T3 but not Met showed statistically significant improvements compared to MI in arrhythmia duration, left atrial diameter (T3 vs. MI 4.33 ± 0.63 vs. 5.65 ± 1.32 mm; p \u3c 0.05), fibrosis (6.1 ± 0.6%, 6.6 ± 0.6% vs. 8.2 ± 0.7%, T3, Met vs. MI, respectively), and aortic vasorelaxation responsiveness to acetylcholine (pD2 6.97 ± 0.22, 6.83 ± 0.21 vs. 6.66 ± 0.22, T3, Met vs. MI, respectively). Quantitative polymerase chain reaction showed that T3 and Met attenuated expression of genes associated with inflammation and oxidative stress and restored expression of ion channels and contractile proteins. Conclusion: These results support comparable efficacy of T3 and Met treatments, suggesting that T3 may provide a therapeutic alternative to standard β-receptor blockade, especially for patients intolerant to treatment with β-blockers after MI
Scars of Invariant Manifolds in Interacting Chaotic Few-Body Systems
We present a novel extension of the concept of scars for the wave functions
of classically chaotic few-body systems of identical particles with rotation
and permutation symmetry. Generically there exist manifolds in classical phase
space which are invariant under the action of a common subgroup of these two
symmetries. Such manifolds are associated with highly symmetric configurations.
If sufficiently stable, the quantum motion on such manifolds displays a notable
enhancement of the revival in the autocorrelation function which is not
directly associated with individual periodic orbits. Rather, it indicates some
degree of localization around an invariant manifold which has collective
characteristics that should be experimentally observable.Comment: 4 pages, RevTeX, 4 PS/EPS-figures, uses psfig.sty, quantum
computation changed, to be published in Physical Review Letter
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