The effect of chest compression frequency on the quality of resuscitation by lifeguards. A prospective randomized crossover multicenter simulation trial

BACKGROUND: The ability to perform high-quality cardiopulmonary resuscitation is one of the basic skills for lifeguards. The aim of the study was to assess the influence of chest compression frequency on the quality of the parameters of chest compressions performed by lifeguards. METHODS: This prospective observational, randomized, crossover simulation study was performed with 40 lifeguards working in Warsaw, Wroclaw, and Poznan, Poland. The subjects then participated in a target study, in which they were asked to perform 2-min cycles of metronome-guided chest compressions at different rates: 80, 90, 100, 110, 120, 130, 140, and 150 compressions per minute (CPM). RESULTS: The study involved 40 lifeguards. Optimal chest compression score calculated by manikin software was achieved for 110-120 CPM. Chest compression depth achieved 53 (interquartile range [IQR] 52-54) mm, 56 (IQR 54-57) mm, 52.5 (IQR 50-54) mm, 53 (IQR 52-53) mm, 50 (IQR 49-51) mm, 47 (IQR 44-51) mm, 41 (IQR 40-42) mm, 38 (IQR 38-43) mm for 80, 90, 100, 110, 120, 130, 140 and 150 CPM, respectively. The percentage of chest compressions with the correct depth was lower for rates exceeding 120 CPM. CONCLUSIONS: The rate of 100-120 CPM, as recommended by international guidelines, is the optimal chest compression rate for cardiopulmonary resuscitation performed by lifeguards. A rate above 120 CPM was associated with a dramatic decrease in chest compression depth and overall chest compression quality. The role of full chest recoil should be emphasized in basic life support training

The drivers of change for the contribution of small farms to regional food security in Europe

The capacity of the food system to respond to the economic, demographic and environmental challenges ahead has become a topic of increasing interest, with particular attention to the roles and responsibilities of the different actors to ensure more sustainable food systems that can guarantee food and nutrition security for all. In this paper we approach the need to better understand the factors that can condition the potential contribution of small farms to regional food and nutrition security in Europe, acknowledging the role that small farms play in Europe at present. The analysis is based on a survey to 94 experts from 17 regions (NUTS3 level) in 11 different European countries, which identified the drivers of change according to the regional experts. These drivers were then categorized and their relative relevance assessed. The results indicate that some relevant drivers in the European context are linked to the capacity to adopt technologies and practices allowing adaptation to climate change, and the capacity to connect to food markets, with emphasis in the need for cooperation and collective action. The weight of other more European-specific drivers such as ‘consumer values and habits’ reveal that the future role of small farms will be very dependent on a societal change, with equity becoming a relevant component of consumers’ choice

Vacuolar organization in the nodule parenchyma is important for the functioning of pea root nodules

Different models have been proposed to explain the operation of oxygen diffusion barrier in root nodules of leguminous plants. This barrier participates in protection of oxygen-sensitive nitrogenase, the key enzyme in nitrogen fixation, from inactivation. Details concerning structural and biochemical properties of the barrier are still lacking. Here, the properties of pea root nodule cortical cells were examined under normal conditions and after shoot removal. Microscopic observations, including neutral red staining and epifluorescence investigations, showed that the inner and outer nodule parenchyma cells exhibit different patterns of the central vacuole development. In opposition to the inner part, the outer parenchyma cells exhibited vacuolar shrinkage and formed cell wall infoldings. Shoot removal induced vacuolar shrinkage and formation of infoldings in the inner parenchyma and uninfected cells of the symbiotic tissue, as well. It is postulated that cells which possess shrinking vacuoles are sensitive to the external osmotic pressure. The cells can give an additional resistance to oxygen diffusion by release of water to the intercellular spaces

Density functional theory based screening of ternary alkali-transition metal borohydrides: A computational material design project

The dissociation of molecules, even the most simple hydrogen molecule, cannot be described accurately within density functional theory because none of the currently available functionals accounts for strong on-site correlation. This problem led to a discussion of properties that the local Kohn-Sham potential has to satisfy in order to correctly describe strongly correlated systems. We derive an analytic expression for the nontrivial form of the Kohn-Sham potential in between the two fragments for the dissociation of a single bond. We show that the numerical calculations for a one-dimensional two-electron model system indeed approach and reach this limit. It is shown that the functional form of the potential is universal, i.e., independent of the details of the two fragments.We acknowledge funding by the Spanish MEC (Grant No. FIS2007-65702-C02-01), “Grupos Consolidados UPV/EHU del Gobierno Vasco” (Grant No. IT-319-07), and the European Community through e-I3 ETSF project (Grant Agreement No. 211956).Peer reviewe

Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial

Background: Many patients with COVID-19 have been treated with plasma containing anti-SARS-CoV-2 antibodies. We aimed to evaluate the safety and efficacy of convalescent plasma therapy in patients admitted to hospital with COVID-19. Methods: This randomised, controlled, open-label, platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]) is assessing several possible treatments in patients hospitalised with COVID-19 in the UK. The trial is underway at 177 NHS hospitals from across the UK. Eligible and consenting patients were randomly assigned (1:1) to receive either usual care alone (usual care group) or usual care plus high-titre convalescent plasma (convalescent plasma group). The primary outcome was 28-day mortality, analysed on an intention-to-treat basis. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936. Findings: Between May 28, 2020, and Jan 15, 2021, 11558 (71%) of 16287 patients enrolled in RECOVERY were eligible to receive convalescent plasma and were assigned to either the convalescent plasma group or the usual care group. There was no significant difference in 28-day mortality between the two groups: 1399 (24%) of 5795 patients in the convalescent plasma group and 1408 (24%) of 5763 patients in the usual care group died within 28 days (rate ratio 1·00, 95% CI 0·93–1·07; p=0·95). The 28-day mortality rate ratio was similar in all prespecified subgroups of patients, including in those patients without detectable SARS-CoV-2 antibodies at randomisation. Allocation to convalescent plasma had no significant effect on the proportion of patients discharged from hospital within 28 days (3832 [66%] patients in the convalescent plasma group vs 3822 [66%] patients in the usual care group; rate ratio 0·99, 95% CI 0·94–1·03; p=0·57). Among those not on invasive mechanical ventilation at randomisation, there was no significant difference in the proportion of patients meeting the composite endpoint of progression to invasive mechanical ventilation or death (1568 [29%] of 5493 patients in the convalescent plasma group vs 1568 [29%] of 5448 patients in the usual care group; rate ratio 0·99, 95% CI 0·93–1·05; p=0·79). Interpretation: In patients hospitalised with COVID-19, high-titre convalescent plasma did not improve survival or other prespecified clinical outcomes. Funding: UK Research and Innovation (Medical Research Council) and National Institute of Health Research

Tocilizumab in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Background: In this study, we aimed to evaluate the effects of tocilizumab in adult patients admitted to hospital with COVID-19 with both hypoxia and systemic inflammation. Methods: This randomised, controlled, open-label, platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing several possible treatments in patients hospitalised with COVID-19 in the UK. Those trial participants with hypoxia (oxygen saturation <92% on air or requiring oxygen therapy) and evidence of systemic inflammation (C-reactive protein ≥75 mg/L) were eligible for random assignment in a 1:1 ratio to usual standard of care alone versus usual standard of care plus tocilizumab at a dose of 400 mg–800 mg (depending on weight) given intravenously. A second dose could be given 12–24 h later if the patient's condition had not improved. The primary outcome was 28-day mortality, assessed in the intention-to-treat population. The trial is registered with ISRCTN (50189673) and ClinicalTrials.gov (NCT04381936). Findings: Between April 23, 2020, and Jan 24, 2021, 4116 adults of 21 550 patients enrolled into the RECOVERY trial were included in the assessment of tocilizumab, including 3385 (82%) patients receiving systemic corticosteroids. Overall, 621 (31%) of the 2022 patients allocated tocilizumab and 729 (35%) of the 2094 patients allocated to usual care died within 28 days (rate ratio 0·85; 95% CI 0·76–0·94; p=0·0028). Consistent results were seen in all prespecified subgroups of patients, including those receiving systemic corticosteroids. Patients allocated to tocilizumab were more likely to be discharged from hospital within 28 days (57% vs 50%; rate ratio 1·22; 1·12–1·33; p<0·0001). Among those not receiving invasive mechanical ventilation at baseline, patients allocated tocilizumab were less likely to reach the composite endpoint of invasive mechanical ventilation or death (35% vs 42%; risk ratio 0·84; 95% CI 0·77–0·92; p<0·0001). Interpretation: In hospitalised COVID-19 patients with hypoxia and systemic inflammation, tocilizumab improved survival and other clinical outcomes. These benefits were seen regardless of the amount of respiratory support and were additional to the benefits of systemic corticosteroids. Funding: UK Research and Innovation (Medical Research Council) and National Institute of Health Research

Towards a reliable star formation history of the galactic disk in the Gaia era

International audienceA new tool is being developed to derive the star formation and chemical enrichment history of the galactic disc through comparison of future Gaia data with synthetic color magnitude diagrams. First steps are being conducted joining two powerful algorithms: IAC-pop/MinnIAC, a code that has widely and very successfully being applied to external galaxies, and the new version of the Besançon Galaxy Model, which allows a good control of the Initial Mass Function, the Star Formation History and the chemical enrichment. A first tuning of these algorithms to the main characteristics of the Gaia data is described, emphasizing the role of the accurate parallaxes, the astrometric and photometric uncertainties and the Gaia observational constraints of the Gaia data. Preliminary tests demonstrate that the methodology proposed here has huge capabilities, although ingredients such as the stellar evolutionary models are critical in the process. The strategy to incorporate higher complexity in the process is discussed

How do small farms contribute to food and nutrition security? Linking European small farms, strategies and outcomes in territorial food systems

Despite a longstanding literature on small farm-households, there is limited consideration of small farms’ role in food and nutrition security (FNS) at territorial level. The purpose of this study is to provide insights about how small farms contribute to FNS at different territorial scales, by focusing on farmers' strategies and consequential FNS outcomes. Analysis is based on two years (2017–2019) of field work done with farmers and food system actors in SALSA reference regions culminating in a workshop done with research partners. We find that small farms deliver food and nutrition security and other socio-economic and environmental outcomes for the farm-household, at local, regional and global levels. The regional level is shown to be critical for small farms, as it provides the scale at which their diversity is realised. Understanding this diversity is a goal for both research and for effective support mechanisms for small farm integration, and the multiple public and private functions small farms can deliver should be higher on the policy agenda