Linear response in the uniformly heated granular gas

We analyse the linear response properties of the uniformly heated granular gas. The intensity of the stochastic driving fixes the value of the granular temperature in the non-equilibrium steady state reached by the system. Here, we investigate two specific situations. First, we look into the ``direct'' relaxation of the system after a single (small) jump of the driving intensity. This study is carried out by two different methods. Not only do we linearise the evolution equations around the steady state, but also derive generalised out-of-equilibrium fluctuation-dissipation relations for the relevant response functions. Second, we investigate the behaviour of the system in a more complex experiment, specifically a Kovacs-like protocol with two jumps in the driving. The emergence of anomalous Kovacs response is explained in terms of the properties of the direct relaxation function: it is the second mode changing sign at the critical value of the inelasticity that demarcates anomalous from normal behaviour. The analytical results are compared with numerical simulations of the kinetic equation, and a good agreement is found.Comment: 14 pages, 10 figures; major revision; completely new section on non-equilibrium FDR; accepted for publication in PR

Non-equilibrium memory effects: granular fluids and beyond

In this perspective paper, we look into memory effects in out-of-equilibrium systems. To be concrete, we exemplify memory effects with the paradigmatic case of granular fluids, although extensions to other contexts such as molecular fluids with non-linear drag are also considered. The focus is put on two archetypal memory effects: the Kovacs and Mpemba effects. In brief, the first is related to imperfectly reaching a steady state -- either equilibrium or non-equilibrium, whereas the second is related to reaching a steady state faster despite starting further. Connections to optimal control theory thus naturally emerge and are briefly discussed.Comment: Perspective paper for EPL, 7 pages, 6 figure

Multimorbidity among registered immigrants in Norway: the role of reason for migration and length of stay

Objectives International migration is rapidly increasing worldwide. However, the health status of migrants differs across groups. Information regarding health at arrival and subsequent periodic follow-up in the host country is necessary to develop equitable health care to immigrants. The objective of this study was to determine the impact of the length of stay in Norway and other sociodemographic variables on the prevalence of multimorbidity across immigrant groups (refugees, labour immigrants, family reunification immigrants and education immigrants). Methods This is a register-based study merging data from the National Population Register and the Norwegian Health Economics Administration database. Sociodemographic variables and multimorbidity across the immigrant groups were compared using Persons’ chi-square test and anova as appropriate. Several binary logistic regression models were conducted. Results Multimorbidity was significantly lower among labour immigrants (OR (95% CI) 0.23 (0.21–0.26) and 0.45 (0.40–0.50) for men and women, respectively) and education immigrants (OR (95% CI) 0.40 (0.32–0.50) and 0.38 (0.33–0.43)) and higher among refugees (OR (95% CI) 1.67 (1.57–1.78) and 1.83 (1.75–1.92)), compared to family reunification immigrants. For all groups, multimorbidity doubled after a five-year stay in Norway. Effect modifications between multimorbidity and sociodemographic characteristics across the different reasons for migration were observed. Conclusions Multimorbidity was highest among refugees at arrival but increased rapidly among labour immigrants, especially females. Health providers need to ensure tailor-made preventive and management strategies that take into account pre-migration and post-migration experiences for immigrants in order to address their needs

Multimorbidity and its patterns according to immigrant origin. A nationwide register-based study in Norway

Introduction As the flows of immigrant populations increase worldwide, their heterogeneity becomes apparent with respect to the differences in the prevalence of chronic physical and mental disease. Multimorbidity provides a new framework in understanding chronic diseases holistically as the consequence of environmental, social, and personal risks that contribute to increased vulnerability to a wide variety of illnesses. There is a lack of studies on multimorbidity among immigrants compared to native-born populations. Methodology This nationwide multi-register study in Norway enabled us i) to study the associations between multimorbidity and immigrant origin, accounting for other known risk factors for multimorbidity such as gender, age and socioeconomic levels using logistic regression analyses, and ii) to identify patterns of multimorbidity in Norway for immigrants and Norwegian-born by means of exploratory factor analysis technique. Results Multimorbidity rates were lower for immigrants compared to Norwegian-born individuals, with unadjusted odds ratios (OR) and 95% confidence intervals 0.38 (0.37–0.39) for Eastern Europe, 0.58 (0.57–0.59) for Asia, Africa and Latin America, and 0.67 (0.66–0.68) for Western Europe and North America. Results remained significant after adjusting for socioeconomic factors. Similar multimorbidity disease patterns were observed among Norwegian-born and immigrants, in particular between Norwegian-born and those from Western European and North American countries. However, the complexity of patterns that emerged for the other immigrant groups was greater. Despite differences observed in the development of patterns with age, such as ischemic heart disease among immigrant women, we were unable to detect the systematic development of the multimorbidity patterns among immigrants at younger ages. Conclusions Our study confirms that migrants have lower multimorbidity levels compared to Norwegian-born. The greater complexity of multimorbidity patterns for some immigrant groups requires further investigation. Health care policies and practice will require a holistic approach for specific population groups in order to meet their health needs and to curb and prevent diseases

Overuse or underuse? Use of healthcare services among irregular migrants in a north-eastern Spanish region

Background: There is little verified information on global healthcare utilization by irregular migrants. Understanding how immigrants use healthcare services based on their needs is crucial to establish effective health policy. We compared healthcare utilization between irregular migrants, documented migrants, and Spanish nationals in a Spanish autonomous community. Methods: This retrospective, observational study included the total adult population of Aragon, Spain: 930, 131 Spanish nationals; 123, 432 documented migrants; and 17, 152 irregular migrants. Healthcare utilization data were compared between irregular migrants, documented migrants and Spanish nationals for the year 2011. Multivariable standard or zero-inflated negative binomial regression models were generated, adjusting for age, sex, length of stay, and morbidity burden. Results: The average annual use of healthcare services was lower for irregular migrants than for documented migrants and Spanish nationals at all levels of care analyzed: primary care (0.5 vs 4 vs 6.7 visits); specialized care (0.2 vs 1.8 vs 2.9 visits); planned hospital admissions (0.3 vs 2 vs 4.23 per 100 individuals), unplanned hospital admissions (0.5 vs 3.5 vs 5.2 per 100 individuals), and emergency room visits (0.4 vs 2.8 vs 2.8 per 10 individuals). The average annual prescription drug expenditure was also lower for irregular migrants (€9) than for documented migrants (€77) and Spanish nationals (€367). These differences were only partially attenuated after adjusting for age, sex, and morbidity burden. Conclusions: Under conditions of equal access, healthcare utilization is much lower among irregular migrants than Spanish nationals (and lower than that of documented migrants), regardless of country of origin or length of stay in Spain

Multimorbidity and weight loss in obese primary care patients: Longitudinal study based on electronic healthcare records

Objective: To analyse the association between cardiovascular and mental comorbidities of obesity and weight loss registered in the electronic primary healthcare records. Design and setting: Longitudinal study of a cohort of adult patients assigned to any of the public primary care centres in Aragon, Spain, during 2010 and 2011. Participants: Adult obese patients for whom data on their weight were available for 2010 (n=62 901), and for both 2010 and 2011 (n=42 428). Outcomes: Weight loss (yes/no) was calculated based on the weight difference between the first value registered in 2010 and the last value registered in 2011. Multivariate logistic regression models were adjusted for individuals' age, sex, total number of chronic comorbidities, type of obesity and length of time between both weight measurements. Results: According to the recorded clinical information, 9 of 10 obese patients showed at least one chronic comorbidity. After adjusting for covariates, weight loss seemed to be more likely among obese patients with a diagnosis of diabetes and/or dementia and less likely among those with hypertension, anxiety and/or substance use problems (p<0.05). The probability of weight loss was also significantly higher in male patients with more severe obesity and older age. Conclusions: An increased probability of weight loss over 1 year was observed in older obese male patients, especially among those already manifesting high levels of obesity and severe comorbidities such as diabetes and/or dementia. Yet patients with certain psychological problems showed lower rates of weight reduction. Future research should clarify if these differences persist beyond potential selective weight documentation in primary care, to better understand the trends in weight reduction among obese patients and the underlying role of general practitioners regarding such trends

Impact of lightning-NO on eastern United States photochemistry during the summer of 2006 as determined using the CMAQ model

A lightning-nitrogen oxide (NO) algorithm is implemented in the Community Multiscale Air Quality Model (CMAQ) and used to evaluate the impact of lightning-NO emissions (LNO&lt;sub&gt;x&lt;/sub&gt;) on tropospheric photochemistry over the United States during the summer of 2006. &lt;br&gt;&lt;br&gt; For a 500 mole per flash lightning-NO source, the mean summertime tropospheric NO&lt;sub&gt;2&lt;/sub&gt; column agrees with satellite-retrieved columns to within −5 to +13%. Temporal fluctuations in the column are moderately well simulated; however, the addition of LNO&lt;sub&gt;x&lt;/sub&gt; does not lead to a better simulation of day-to-day variability. The contribution of lightning-NO to the model column ranges from &amp;sim;10% in the northern US to &gt;45% in the south-central and southeastern US. Lightning-NO adds up to 20 ppbv to upper tropospheric model ozone and 1.5–4.5 ppbv to 8-h maximum surface layer ozone, although, on average, the contribution of LNO&lt;sub&gt;x&lt;/sub&gt; to model surface ozone is 1–2 ppbv less on poor air quality days. LNO&lt;sub&gt;x&lt;/sub&gt; increases wet deposition of oxidized nitrogen by 43% and total deposition of nitrogen by 10%. This additional deposition reduces the mean magnitude of the CMAQ low-bias in nitrate wet deposition with respect to National Atmospheric Deposition monitors to near zero. &lt;br&gt;&lt;br&gt; Differences in urban/rural biases between model and satellite-retrieved NO&lt;sub&gt;2&lt;/sub&gt; columns were examined to identify possible problems in model chemistry and/or transport. CMAQ columns were too large over urban areas. Biases at other locations were minor after accounting for the impacts of lightning-NO emissions and the averaging kernel on model columns. &lt;br&gt;&lt;br&gt; In order to obtain an upper bound on the contribution of uncertainties in NO&lt;sub&gt;y&lt;/sub&gt; chemistry to upper tropospheric NO&lt;sub&gt;x&lt;/sub&gt; low biases, sensitivity calculations with updated chemistry were run for the time period of the Intercontinental Chemical Transport Experiment (INTEX-A) field campaign (summer 2004). After adjusting for possible interferences in NO&lt;sub&gt;2&lt;/sub&gt; measurements and averaging over the entire campaign, these updates reduced 7–9 km biases from 32 to 17% and 9–12 km biases from 57 to 46%. While these changes lead to better agreement, a considerable unexplained NO&lt;sub&gt;2&lt;/sub&gt; low-bias remains in the uppermost troposphere

Visual Function and Brief Cognitive Assessment for Multiple Sclerosis (BICAMS) in Optic Neuritis Clinically Isolated Syndrome Patients

BACKGROUND: In this study, we hypothesized that clinically isolated syndrome–optic neuritis patients may have disturbances in neuropsychological functions related to visual processes. METHODS: Forty-two patients with optic neuritis within 3 months from onset and 13 healthy controls were assessed at baseline and 6 months with MRI (brain volumes, lesion load, and optic radiation lesion volume) and optical coherence tomography (OCT) (peripapillary retinal nerve fiber layer [RNFL], ganglion cell and inner plexiform layers [GCIPLs], and inner nuclear layer). Patients underwent the brief cognitive assessment for multiple sclerosis, high-contrast and low-contrast letter acuity, and color vision. RESULTS: At baseline, patients had impaired visual function, had GCIPL thinning in both eyes, and performed below the normative average in the visual-related tests: Symbol Digit Modalities Test and Brief Visuospatial Memory Test-Revised (BVMT-R). Over time, improvement in visual function in the affected eye was predicted by baseline GCIPL (P = 0.015), RNFL decreased, and the BVMT-R improved (P = 0.001). Improvement in BVMT-R was associated with improvement in the high-contrast letter acuity of the affected eye (P = 0.03), independently of OCT and MRI metrics. CONCLUSION: Cognitive testing, assessed binocularly, of visuospatial processing is affected after unilateral optic neuritis and improves over time with visual recovery. This is not related to structural markers of the visual or central nervous system

Chronic Obstructive Pulmonary Disease and Incidence of Hip Fracture: A Nested Case-Control Study in the EpiChron Cohort

Purpose: To determine whether chronic obstructive pulmonary disease (COPD) is a risk factor for hip fracture and identify other factors associated with hip fracture. Patients and Methods: Observational nested case-control study was conducted in Aragon, Spain in 2010. We included COPD patients aged >40 years, in the EpiChron cohort. Each COPD patient was matched for age, sex, and number of comorbidities with a control subject without COPD. Patients with an existing diagnosis of osteoporosis and those with hip fracture before 2011 were excluded. We collected baseline demographic, comorbidity, and pharmacological treatment data. During a 5-year follow-up period, we recorded the incidence of hip fracture. A logistic regression model was constructed to identify factors associated with hip fracture. Results: The study population consisted of 26, 517 COPD patients and the same number of controls (median [interquartile range] age, 74 [17] years; women, 24.7%). Smoking and heart failure were more frequent in COPD patients, and obesity, hypertension, diabetes, dyslipidemia, stroke, arthritis, and visual or hearing impairment were less frequent (all p<0.001). Consumption of benzodiazepines (p=0.037), bronchodilators (p<0.001), and corticosteroids (p<0.001) was higher in the COPD group, while that of beta-blockers and thiazides was lower (both p<0.001). During follow-up, 898 (1.7%) patients experienced hip fracture, with no differences observed between COPD and control patients. Multivariate analysis revealed that independent of COPD status, age, female sex, chronic liver disease, heart failure, and benzodiazepine use were independently associated with a higher risk of hip fracture, and obesity with a lower risk. In COPD patients, use of inhaled anticholinergics was independently associated with hip fracture (OR, 1.390; 95% CI 1.134-1.702; p=0.001). Conclusion: COPD is not a risk factor for a hip fracture within 5 years. The association between the use of inhaled anticholinergics and risk of hip fracture warrants further study