Due to the dramatic impact of the COVID-19 pandemic, Spain underwent a strict lockdown (March–May 2020). How the lockdown modified older adults’ physical activity (PA) has been poorly described. This research assesses the effect of the lockdown on PA levels and identifies predictors of sufficient/insufficient PA in frail older community-dwellers. Community-dwelling participants from the +ÀGIL Barcelona frailty intervention program, suspended during the pandemic, underwent a phone-assessment during the lockdown. PA was measured before and after the lockdown using the Brief Physical Activity Assessment Tool (BPAAT). We included 98 frail older adults free of COVID-19 (mean age = 82.7 years, 66.3% women, mean Short Physical Performance Battery = 8.1 points). About one third of participants (32.2%) were not meeting sufficient PA levels at the end of the lockdown. Depressive symptoms (OR = 0.12, CI95% = 0.02–0.55) and fatigue (OR = 0.11, CI95% = 0.03–0.44) decreased the odds of maintaining sufficient PA, whereas maintaining social networks (OR = 5.07, CI95% = 1.60–16.08) and reading (OR = 6.29, CI95% = 1.66–23.90) increased it. Living alone was associated with the reduction of PA levels (b = −1.30, CI95% = −2.14–−0.46). In our sample, pre-lockdown mental health, frailty-related symptoms and social relationships were consistently associated with both PA levels during-lockdown and pre-post change. These data suggest considering specific plans to maintain PA levels in frail older community-dwellers.

Exercise is a form of physical activity (PA). PA is an important marker of health and quality of life in older adults. The purpose of this study was to conduct a systematic review of the literature to assess the effect of exercise-based interventions on an at least six-month follow up PA measure, and to describe the specific strategies implemented during the intervention to strengthen the sustainability of PA in community-dwelling 65+ year-old adults. We registered and conducted a systematic review and meta-analysis (PROSPERO: CRD42017070892) of randomized clinical trials (RCT). We searched three electronic databases during January 2018 to identify RCT assessing any type of exercise-based intervention. Studies had to report a pre-, post-, and at least 6-month post-intervention follow-up. To be included, at least one PA outcome had to be assessed. The effect of exercise-based interventions was assessed compared to active (e.g., a low-intensity type of exercise, such as stretching or toning activities) and non-active (e.g., usual care) control interventions at several time points. Secondary analyses were conducted, restricted to studies that reported specific strategies to enhance the sustainability of PA. The intervention effect was measured on self-reported and objective measures of time spent in PA, by means of standardized mean differences. Standardized mean differences of PA level were pooled. Pooled estimates of effect were computed with the DerSimonian–Laird method, applying a random effects model. The risk of bias was also assessed. We included 12 studies, comparing 18 exercise intervention groups to four active and nine non-active control groups. Nine studies reported specific strategies to enhance the long-term sustainability of PA. The strategies were mostly related to the self-efficacy, self-control, and behavior capability principles based on the social cognitive theory. Exercise interventions compared to active control showed inconclusive and heterogeneous results. When compared to non-active control, exercise interventions improved PA time at the six-months follow up (standardized mean difference (SMD) 0.30; 95%CI 0.15 to 0.44; four studies; 724 participants; I2 0%), but not at the one- or two-years follow-ups. No data were available on the mid- and long-term effect of adding strategies to enhance the sustainability of PA. Exercise interventions have small clinical benefits on PA levels in community-dwelling older adults, with a decline in the observed improvement after six months of the intervention cessation.

Bicarbonate plays a fundamental role in the cell pH status in all organisms. In autotrophs, HCO3− may further contribute to carbon concentration mechanisms (CCM). This is especially relevant in the CO2-poor habitats of cyanobacteria, aquatic microalgae, and macrophytes. Photosynthesis of terrestrial plants can also benefit from CCM as evidenced by the evolution of C4 and Crassulacean Acid Metabolism (CAM). The presence of HCO3− in all organisms leads to more questions regarding the mechanisms of uptake and membrane transport in these different biological systems. This review aims to provide an overview of the transport and metabolic processes related to HCO3− in microalgae, macroalgae, seagrasses, and terrestrial plants. HCO3− transport in cyanobacteria and human cells is much better documented and is included for comparison. We further comment on the metabolic roles of HCO3− in plants by focusing on the diversity and functions of carbonic anhydrases and PEP carboxylases as well as on the signaling role of CO2/HCO3− in stomatal guard cells. Plant responses to excess soil HCO3− is briefly addressed. In conclusion, there are still considerable gaps in our knowledge of HCO3− uptake and transport in plants that hamper the development of breeding strategies for both more efficient CCM and better HCO3− tolerance in crop plants.

Background: Delirium research is poorly studied in postacute care, a growing setting due to aging populations, as well as in dementia, a critical risk factor for delirium and particularly prevalent in postacute care. We investigated risk factors for delirium and its outcomes in older adults with and without dementia admitted to a subacute care unit (SCU) after exacerbated chronic conditions. Methods: This is a prospective cohort study including patients ≥65 years old admitted to an SCU for 12 months. We collected demographics, comprehensive geriatric assessments, and presence of dementia and delirium at admission. Outcomes included discharge to previous living situation, mortality, and functional evolution. Due to the high prevalence of dementia, a subgroup analysis was performed to investigate specific risk factors for delirium and related outcomes. Results: Of 909 patients (mean age [±SD] 85.8 ± 6.7; 60% women, 47.5% with dementia), 352 (38.7%) developed delirium. The main risk factor for delirium was dementia (HR [95% CI] 5.2 [3.5–7.7]); age, functional status, and urinary tract infections were also independently associated with delirium. In dementia patients, only age (HR [95% CI] 1.0 [1.004–1.1]) and being male (HR [95% CI] 1.7 [1.04–2.6]) were associated with delirium. Delirium was associated with greater mortality (10.8 vs. 3.9%; p < 0.001) and greater functional decline in the entire sample (–12.3 vs. –6.4 Barthel index points; p < 0.001). In the dementia subgroup, patients with delirium experienced greater functional loss (p = 0.013) and less functional recovery (p = 0.025). Conclusions: In older patients admitted to postacute care, dementia is the main risk factor for delirium, and delirium carries worse clinical and functional outcomes. In patients with dementia, delirium is also relevant, since it entails a functional loss at admission and lower functional recovery.