66 research outputs found
A numerical study of the development of bulk scale-free structures upon growth of self-affine aggregates
During the last decade, self-affine geometrical properties of many growing
aggregates, originated in a wide variety of processes, have been well
characterized. However, little progress has been achieved in the search of a
unified description of the underlying dynamics. Extensive numerical evidence
has been given showing that the bulk of aggregates formed upon ballistic
aggregation and random deposition with surface relaxation processes can be
broken down into a set of infinite scale invariant structures called "trees".
These two types of aggregates have been selected because it has been
established that they belong to different universality classes: those of
Kardar-Parisi-Zhang and Edward-Wilkinson, respectively. Exponents describing
the spatial and temporal scale invariance of the trees can be related to the
classical exponents describing the self-affine nature of the growing interface.
Furthermore, those exponents allows us to distinguish either the compact or
non-compact nature of the growing trees. Therefore, the measurement of the
statistic of the process of growing trees may become a useful experimental
technique for the evaluation of the self-affine properties of some aggregates.Comment: 19 pages, 5 figures, accepted for publication in Phys.Rev.
Dietary patterns, foods, and food groups : relation to late-life cognitive disorders
The limited efficacy of disease-modifying therapeutic strategies for mild cognitive impairment (MCI) and Alzheimer\u2019s dementia (AD) underscores the need for preventive measures to reduce the burden of late-life cognitive impairment. The aim of the present review article was to investigate the relationship among dietary patterns, foods, and food groups and late-life cognitive disorders considering the results of observational studies published in the last three years (2014-2016). In the last decade, the association between diet and cognitive function or dementia has been largely investigated. However, more recently, the National Institute on Aging-Alzheimer\u2019s Association guidelines for AD and cognitive decline due to AD pathology introduced some evidence suggesting a direct relation between diet and changes in the brain structure and activity. Several studies focused on the role of the dietary patterns on late-life cognition, with accumulating evidence that combinations of foods and nutrients into certain patterns may act synergistically to provide stronger health effects than those conferred by their individual dietary components. In particular, higher adherence to a Mediterranean-type diet was associated with decreased cognitive decline, although the Mediterranean diet (MeDi) combines several foods, micronutrients, and macronutrients already separately proposed as potential protective factors against dementia and MCI. Moreover, also other emerging healthy dietary patterns such as the Dietary Approach to Stop Hypertension (DASH) and the Mediterranean-DASH diet Intervention for Neurodegenerative Delay (MIND) diets were associated with slower rates of cognitive decline and significant reduction in AD rate. Furthermore, some foods or food groups traditionally considered harmful such as eggs and red meat have been partially rehabilitated, while there is still a negative correlation of cognitive functions with added sugars and trans fatty acids, nutrients also increasing the cardiovascular risk. This would suggest a genesis for the same damage for aging brain
Dietary intervention and prevention of cognitive-related outcomes in healthy older adults without cognitive dysfunction
In the last decade, the association between diet and cognitive function/dementia has been largely investigated in observational studies, while there was a lack of evidence from randomized clinical trials (RCTs) on the prevention of late-life cognitive disorders though dietary intervention in cognitively healthy older adults. In the present article, we reviewed RCTs published in the last three years (2014-2016) exploring nutritional intervention efficacy in preventing the onset of late-life cognitive disorders and dementia in cognitively healthy subjects aged over 60 years using different levels of investigation (i.e., dietary pattern changes/ medical food/nutraceutical supplementation/multidomain approach and dietary macro-and micronutrient approaches). From the included RCTs, there was moderate evidence that intervention through dietary pattern changes, medical food/nutraceutical supplementation, and multidomain approach improved specific cognitive domains or cognitive-related blood biomarkers. Moreover, there was high evidence that protein supplementation improved specific cognitive domains. For fatty acid supplementation, mainly long-chain polyunsaturated fatty acids, there was emerging evidence suggesting an impact of this approach in improving specific cognitive domains, MRI findings, and/or cognitive-related biomarkers also in selected subgroups of older subjects although some results were conflicting. Moreover, there was convincing evidence of an impact of non-flavonoid polyphenol and flavonoid supplementations in improving specific cognitive domains and/or MRI findings. Finally, there was only low evidence suggesting efficacy of intervention with homocysteine-related vitamins in improving cognitive functions, dementia incidence, or cognitive-related biomarkers in cognitively healthy older subjects
Multiparticle Biased DLA with surface diffusion: a comprehensive model of electrodeposition
We present a complete study of the Multiparticle Biased Diffusion-Limited
Aggregation (MBDLA) model supplemented with surface difussion (SD), focusing on
the relevance and effects of the latter transport mechanism. By comparing
different algorithms, we show that MBDLA+SD is a very good qualitative model
for electrodeposition in practically all the range of current intensities {\em
provided} one introduces SD in the model in the proper fashion: We have found
that the correct procedure involves simultaneous bulk diffusion and SD,
introducing a time scale arising from the ratio of the rates of both processes.
We discuss in detail the different morphologies obtained and compare them to
the available experimental data with very satisfactory results. We also
characterize the aggregates thus obtained by means of the dynamic scaling
exponents of the interface height, allowing us to distinguish several regimes
in the mentioned interface growth. Our asymptotic scaling exponents are again
in good agreement with recent experiments. We conclude by discussing a global
picture of the influence and consequences of SD in electrodeposition.Comment: 15 pages, 20 figures, accepted for publication in Physical Review
Nutritional interventions in patients with Alzheimer’s disease and other late-life cognitive disorders
Given the impact of nutrition on neuroprotection largely investigated in observational studies, in the present article, we reviewed evidence from randomized clinical trials (RCTs) published in the last three years (2014-2016) exploring nutritional intervention efficacy in slowing cognitive impairment progression and achieving cognitive-related outcomes in patients aged 60 years and older with mild cognitive impairment (MCI), preclinical Alzheimer\u2019s disease (AD), prodromal AD, AD, unspecified dementia, and vascular dementia using different levels of investigation (i.e., medical food/nutraceutical supplementation/multidomain approach and dietary food/macro-and micronutrient approaches). From the reviewed RCTs, there was emerging evidence that nutritional intervention through medical food/nutraceutical supplementation (Fortasyn Connect\uae and another similar nutraceutical formulation) and multidomain approach improved magnetic resonance imaging findings and other cognitive-related biomarkers, but without clear effect on cognition in mild AD and MCI. Moreover, there was some evidence of a positive effect of antioxidant-rich foods (nuts) in improving specific cognitive domains and cognitive-related outcomes in MCI and mild-to-moderate dementia, but only in small samples. There was also convincing evidence for fatty acid supplementation, mainly n-3 polyunsaturated fatty acids (PUFAs), in improving specific cognitive domains and/or cognitive-related biomarkers in MCI and AD. Furthermore, antioxidant vitamin and trace element supplementations improved only cognitive-related outcomes and biomarkers, without effect on cognitive function in AD and MCI patients. Finally, high-dose B vitamin supplementation in AD and MCI patients improved cognitive outcomes but only in the subjects with a high baseline plasma n-3 PUFA, while folic acid supplementation had positive impact on specific cognitive domains
Clinical features and outcomes of elderly hospitalised patients with chronic obstructive pulmonary disease, heart failure or both
Background and objective: Chronic obstructive pulmonary disease (COPD) and heart failure (HF) mutually increase the risk of being present in the same patient, especially if older. Whether or not this coexistence may be associated with a worse prognosis is debated. Therefore, employing data derived from the REPOSI register, we evaluated the clinical features and outcomes in a population of elderly patients admitted to internal medicine wards and having COPD, HF or COPD + HF. Methods: We measured socio-demographic and anthropometric characteristics, severity and prevalence of comorbidities, clinical and laboratory features during hospitalization, mood disorders, functional independence, drug prescriptions and discharge destination. The primary study outcome was the risk of death. Results: We considered 2,343 elderly hospitalized patients (median age 81 years), of whom 1,154 (49%) had COPD, 813 (35%) HF, and 376 (16%) COPD + HF. Patients with COPD + HF had different characteristics than those with COPD or HF, such as a higher prevalence of previous hospitalizations, comorbidities (especially chronic kidney disease), higher respiratory rate at admission and number of prescribed drugs. Patients with COPD + HF (hazard ratio HR 1.74, 95% confidence intervals CI 1.16–2.61) and patients with dementia (HR 1.75, 95% CI 1.06–2.90) had a higher risk of death at one year. The Kaplan–Meier curves showed a higher mortality risk in the group of patients with COPD + HF for all causes (p = 0.010), respiratory causes (p = 0.006), cardiovascular causes (p = 0.046) and respiratory plus cardiovascular causes (p = 0.009). Conclusion: In this real-life cohort of hospitalized elderly patients, the coexistence of COPD and HF significantly worsened prognosis at one year. This finding may help to better define the care needs of this population
Sex-Differences in the Pattern of Comorbidities, Functional Independence, and Mortality in Elderly Inpatients: Evidence from the RePoSI Register
Background: The RePoSi study has provided data on comorbidities, polypharmacy, and sex dimorphism in hospitalised elderly patients. Methods: We retrospectively analysed data collected from the 2010, 2012, 2014, and 2016 data sets of the RePoSi register. The aim of this study was to explore the sex-differences and to validate the multivariate model in the entire dataset with an expanded follow-up at 1 year. Results: Among 4714 patients, 51% were women and 49% were men. The disease distribution showed that diabetes, coronary artery disease, chronic obstructive pulmonary disease, chronic kidney disease, and malignancy were more frequent in men but that hypertension, anaemia, osteoarthritis, depression, and diverticulitis disease were more common in women. Severity and comorbidity indexes according to the Cumulative Illness Rating Scale (CIRS-s and CIRS-c) were higher in men, while cognitive impairment, mood disorders, and disability in daily life measured by the Barthel Index (BI) were worse in women. In the multivariate analysis, BI, CIRS, and malignancy significantly increased the risk of death in men at the 1-year follow-up, while age was independently associated with mortality in women. Conclusions: Our study highlighted the relevance and the validity of our previous predictive model in the identification of sex dimorphism in hospitalised elderly patients underscoring the need of sex-personalised health-care
Viticulture in Argentina under extreme weather scenarios: Actual challenges, future perspectives
Viticulture in Argentina is an important socioeconomic sector, reflected in a significant wine market and tourism. However, climate change and related extreme events are serious concerns. The main issues are heatwaves, hailstorms, and heavy rainfall, resulting in damage to vineyards. While climate change impacts have already been discussed for regions such as the Mediterranean, the literature lacks an up-to-date overview of Argentine viticulture and potential mitigation solutions. In a country culturally and economically connected to the world of wine, it is strategic to bridge this gap to be prepared for a climatically adverse future. This perspective paper presents an overview of Argentine viticulture and its relationship to climate change. We focus on the Mendoza region, one of the most productive areas and home to cultural landscapes where internationally recognized wines are produced. Climate change is already occurring, a fact we observed by analyzing data from the past decades. We discussed how heatwaves in the lowlands drive farmers to move to the Andes slopes looking for more favorable conditions. But new threats arise, such as extreme rainfall. Due to surface hydrological processes, they can cause land degradation and compromise vineyards. We investigate these phenomena in detail, highlighting how they represent a growing challenge that must be addressed for the sustainable development of future viticulture in the area. Therefore, we propose mitigation strategies for more resilient production, drawing inspiration from the Sustainable Development Goals and suggesting a framework that can be extended to broader contexts worldwide
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