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Diatoms are generally the dominant contributors to the Arctic Ocean spring bloom, which is a key event in regional food webs in terms of capacity for secondary production and organic matter export. Dissolved silicic acid is an obligate nutrient for diatoms and has been declining in the European Arctic since the early 1990s. The lack of regional silicon cycling information precludes understanding the consequences of such changes for diatom productivity during the Arctic spring bloom. This study communicates the results from a cruise in the European Arctic around Svalbard, which reports the first concurrent data on biogenic silica production and export, export of diatom cells, the degree of kinetic limitation by ambient silicic acid, and diatom contribution to primary production. Regional biogenic silica production rates were significantly lower than those achievable in the Southern Ocean and silicic acid concentration limited the biogenic silica production rate in 95 % of samples. Compared to diatoms in the Atlantic subtropical gyre, regional diatoms are less adapted for silicic acid uptake at low concentration, and at some stations during the present study, silicon kinetic limitation may have been intense enough to limit diatom growth. Thus, silicic acid can play a critical role in diatom spring bloom dynamics. The diatom contribution to primary production was variable, ranging from

The ice-covered central Arctic Ocean is characterized by low primary productivity due to light and nutrient limitations. The recent reduction in ice cover has the potential to substantially increase phytoplankton primary production, but little is yet known about the fate of the ice-associated primary production and of the nutrient supply with increasing warming. This study presents results from the central Arctic Ocean collected during summer 2012, when sea-ice extent reached its lowest ever recorded since the onset of satellite observations. Net primary productivity (NPP) was measured in the water column, sea ice and melt ponds by 14CO2 uptake at different irradiances. Photosynthesis vs. irradiance (PI) curves were established in laboratory experiments and used to upscale measured NPP to the deep Eurasian Basin (north of 78° N) using the irradiance-based Central Arctic Ocean Primary Productivity (CAOPP) model. In addition, new annual production has been calculated from the seasonal nutrient drawdown in the mixed layer since last winter. Results show that ice algae can contribute up to 60% to primary production in the central Arctic Ocean at the end of the productive season (August–September). The ice-covered water column has lower NPP rates than open water due to light limitation in late summer. As indicated by the nutrient ratios in the euphotic zone, nitrate was limiting primary production in the deep Eurasian Basin close to the Laptev Sea area, while silicate was the main limiting nutrient at the ice margin near the Atlantic inflow. Although sea-ice cover was substantially reduced in 2012, total annual new production in the Eurasian Basin was 17 ± 7 Tg C yr−1, which is within the range of estimates of previous years. However, when adding the contribution by sub-ice algae, the annual production for the deep Eurasian Basin (north of 78° N) could double previous estimates for that area with a surplus of 16 Tg C yr−1. Our data suggest that sub-ice algae are an important component of the productivity in the ice-covered Eurasian Basin of the central Arctic Ocean. It remains an important question whether their contribution to productivity is on the rise with thinning ice, or whether it will decline due to overall sea-ice retreat and be replaced by phytoplankton.

Abstract To investigate the association between three selected pain polymorphisms and clinical, functional, sensory-related, psychophysical, psychological or cognitive variables in a sample of women with fibromyalgia (FMS). One hundred twenty-three (n = 123) women with FMS completed demographic (age, height, weight), clinical (years with pain, intensity of pain at rest and during daily living activities), functional (quality of life, physical function), sensory-related (sensitization-associated and neuropathic-associated symptoms), psychophysical (pressure pain thresholds), psychological (sleep quality, depressive and anxiety level) and cognitive (pain catastrophizing, kinesiophobia) variables. Those three genotypes of the OPRM1 rs1799971, HTR1B rs6296 and COMT rs4680 single nucleotide polymorphisms were obtained by polymerase chain reactions from no-stimulated whole saliva collection. No significant differences in demographic, clinical, functional, sensory-related, psychophysical, psychological and cognitive variables according to OPRM1 rs1799971, HTR1B rs6296 or COMT rs4680 genotype were identified in our sample of women with FMS. A multilevel analysis did not either reveal any significant gene-to-gene interaction between OPRM1 rs1799971 x HTR1B rs6296, OPRM1 rs1799971 x COMT rs4680 and HTR1B rs6296 x COMT rs4680 for any of the investigated outcomes. This study revealed that three single nucleotide polymorphisms, OPRM1 rs1799971, HTR1B rs6296 or COMT rs4680, mostly associated with chronic pain were not involved in phenotyping features of FMS. Potential gene-to-gene interaction and their association with clinical phenotype in women with FMS should be further investigated in future studies including large sample sizes.

The aim of this study was to quantify the multivariate relationships between clinical, cognitive performance, executive functioning, and psychological outcomes in women with fibromyalgia (FMS) using network analyses. Demographic (age, height, weight), clinical (pain history, pain intensity, and related disability), neurocognitive (D2 Attention test, Rey-Osterrieth Complex Figure for visual perception, “Digits D/R/I” tests of the WAIS-IV battery for working memory, the 5-Digit Test for mental inhibition, the Symbol Search for processing speed and the Zoo Test for planning/decision making) and psychological (depressive symptoms, anxiety levels, sleep quality, pain hypervigilance) variables were collected in 129 women with FMS and 111 healthy women. Network analyses were conducted separately for each group to quantify the adjusted correlations between the modeled variables and to assess their centrality indices (i.e., connectivity with other symptoms in the network and their importance in the network). The network identified 74 associations in FMS women and 46 associations in controls with small differences. The strongest correlations in both groups were found between different attention variables: d2_CON with d2_C, d2_O with d_2TR, and d2_CON with d2_TA. The most central variables were d2_TA, d2_C, and d2_CON (highest strength centrality in both groups) and anxiety levels and pain hypervigilance (highest harmonic centrality in FMS women). The strength centrality of the network was stable for women with FMS (CScor0.7: 0.68) but not for healthy women (CScor0.7: 0.28). This study found that attention variables are most relevant within a neurocognitive network and that psychological variables are most important for the treatment of women with FMS. The clinical implications of the current findings, such as the development of treatments targeting these variables, are discussed.

The coronavirus pandemic has a high impact on mental health, as for example, anxiety. It was the main goal of this study to investigate if rumination and worry mediate the possible relation of self-compassion and fear of the future in females and males of three European and three Middle Eastern countries during the coronavirus pandemic. 2765 men and women participated and answered questions regarding their fear of the future on the one hand and completed the reflection-rumination questionnaire, the Penn-state worry questionnaire, and the self-compassion scale. The results of a mediation analysis demonstrated a relation between self-compassion and fear of the future, which was mediated by worry but not by rumination, independent of gender and country. Furthermore, the fear of the future variable was predicted by different factors in each country. The only clear difference between the participants of the European and the Middle Eastern countries was that women show more fear of the future only in the European countries but not in the Middle Eastern countries. However, there were also differences between the three European and the three Middle Eastern countries. The results indicate that in general, psychological consequences of the coronavirus pandemic should be investigated for each country separately. It does not to seem possible to infer results from one country to another country even on the same continent.

Previous studies on metacognitive performance have explored children’s abilities during primary school (7–11 years) in abstract and mathematical reasoning tasks. However, there have been no studies evaluating the metamemory processes with spatial tasks in primary school children, and even more generally, only a few studies have explored spatial metacognition in adults. Taking as a preliminary study a Spanish school, the present work explores the validity of the confidence judgment model when thinking about one’s own performance in a spatial test, for boys and girls in Second Year of Primary Education (mean age of 7 years). A total of 18 boys and 15 girls applied a 4-point scale to evaluate, item by item, the confidence of their responses in the Spatial aptitude test “E” of the EFAI-1 (Factorial Assessment of Intellectual Abilities to mentally process visual stimuli). Accessibility and Accuracy Indexes were calculated for each item of the spatial task. The effect of gender was analyzed too. The tasks were administered in small groups; at the end examiners interviewed each participant, performing the confidence judgment task, item by item, of the EFAI-1 previously answered. The results (analyses carried out by SPSS) showed a high mean confidence (3 mean points out of a maximum of 4), without finding any significant differences either in the spatial performance or in the mean confidence rating between boys and girls. A significant relationship between confidence judgments and spatial task performance accuracy was found. The relationship between confidence judgments and spatial performance cannot be confirmed. The procedure adapted for testing spatial judgments about the own responses has been useful for showing the well calibrated perception about performance at this stage. The implications of the results of this exploratory study and the potential of the application of the procedure to promote thought about one’s own spatial performance and the development of strategies that modulate the effective approach of this type of spatial tasks are discussed within an educational approach.

Currently, there is evidence that spatial skills training leads to an improvement of such skills, although studies with children in the Preschool stage are very scarce. This paper aims to examine the effectiveness of mental rotation (MR) training and sex differences in preschool children. Two experiments were carried out. Experiment 1 included 59 children of 1st course (aged between 3 and 4 years) and Experiment 2, 61 children of 2nd course (aged between 4 and 5 years) of Preschool Education, distributed into control and training groups. The results showed a significant improvement in the MR ability of the training group (measured through a different test than the one used for training) only in the older children, and a tendency toward significance in the younger participants. Moreover, no sex differences in MR or group differences across age groups were found. These results regarding MR training support the malleability of spatial skills approach, particularly in 4–5 year-old preschoolers. This malleability should be enhanced in our educational system, as well as the implementation of educational and social policies that tend toward equality between sexes in the development of spatial skills. This can promote an equitable access to academic careers requiring high spatial skills such as engineering, science, technology or mathematics, in which nowadays women are underrepresented.

Objective: The aim of this study was to analyze the feasibility of a new resuscitation strategy in which breaths are provided during automated external defibrillator (AED) rhythm analysis, and to evaluate its impact on chest compressions (CC) quality and the peri -analysis time., Method: A randomized simulation study, comparing two cardiopulmonary resuscitations strategies, has been conducted: the standard strategy (S1) with strategy involving ventilation during AED analysis (S2). Thirty lifeguards have performed both strategies in a cross-over study design during 10 min of CPR., Results: The number of ventilations per 10 min increases from 47 (S1) to 72 (S2) ( p  < 0.001). This results in the delivery of an additional 17.1 L of insufflated air in S2 compared to S1 ( p  < 0.001). There have been no significant changes in frequency and total number of CC. These findings correspond to a reduction of the non-ventilation period from 176 s (S1) to 48 s (S2)., Conclusions: This simulation study suggests that it is feasible to increase the number of ventilations during resuscitation following drowning, without affecting the quantity and quality of chest compressions. The results of this study may serve as a foundation for further investigation into optimal ventilation strategies in this context., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Enhancing ocean productivity by artificial upwelling is evaluated as a nature-based solution for food security and climate change mitigation. Fish production is intended through diatom-based plankton food webs as these are assumed to be short and efficient. However, our findings from mesocosm experiments on artificial upwelling in the oligotrophic ocean disagree with this classical food web model. Here, diatoms did not reduce trophic length and instead impaired the transfer of primary production to crustacean grazers and small pelagic fish. The diatom-driven decrease in trophic efficiency was likely mediated by changes in nutritional value for the copepod grazers. Whilst diatoms benefitted the availability of essential fatty acids, they also caused unfavorable elemental compositions via high carbon-to-nitrogen ratios (i.e. low protein content) to which the grazers were unable to adapt. This nutritional imbalance for grazers was most pronounced in systems optimized for CO 2 uptake through carbon-to-nitrogen ratios well beyond Redfield. A simultaneous enhancement of fisheries production and carbon sequestration via artificial upwelling may thus be difficult to achieve given their opposing stoichiometric constraints. Our study suggest that food quality can be more critical than quantity to maximize food web productivity during shorter-term fertilization of the oligotrophic ocean., (© 2024. The Author(s).)

(1) Objective: The objective was to evaluate the quality of cardiopulmonary resuscitation (CPR, chest compressions and ventilations) when performed by a lone first responder on an infant victim via the over-the-head technique (OTH) with bag-mask ventilation in comparison with the standard lateral technique (LAT) position. (2) Methods: A randomized simulation crossover study in a baby manikin was conducted. A total of 28 first responders performed each of the techniques in two separate CPR tests (15:2 chest compressions:ventilations ratio), each lasting 5 min with a 15 min resting period. Quality CPR parameters were assessed using an app connected to the manikin. Those variables were related to chest compressions (CC: depth, rate, and correct CC point) and ventilation (number of effective ventilations). Additional variables included perceptions of the ease of execution of CPR. (3) Results: The median global CPR quality (integrated CC + V) was 82% with OTH and 79% with LAT ( p = 0.94), whilst the CC quality was 88% with OTH and 80% with LAT ( p = 0.67), and ventilation quality was 85% with OTH and 85% with LAT ( p = 0.98). Correct chest release was significantly better with OTH (OTH: 92% vs. LAT: 62%, p < 0.001). There were no statistically significant differences in the remaining variables. Ease of execution perceptions favored the use of LAT over OTH. (4) Conclusions: Chest compressions and ventilations can be performed with similar quality in an infant manikin by lifeguards both with the standard recommended position (LAT) and the alternative OTH. This option could give some advantages in terms of optimal chest release between compressions. Our results should encourage the assessment of OTH in some selected cases and situations as when a lone rescuer is present and/or there are physical conditions that could impede the lateral rescue position.

Uncontrolled external bleeding is a common cause of preventable death, and due to the environment in which these events often occur, e.g., in hostile environments, the state security forces are usually the first responders, and in many cases, if they are injured their partners provide the initial assistance. The tourniquet is a fast, effective, and easy-to-learn intervention, although there is a knowledge gap concerning training techniques. The objective is to evaluate the effectiveness of a bleeding control training program on a high-fidelity mannequin in a simulated critical situation in a law enforcement training environment. A quasi-experimental study was carried out with 27 members of the state security forces. They underwent brief theoretical-practical training and were evaluated via a scenario involving a critically ill patient in a hostile environment. The results showed that no member of the state security forces completed all the tourniquet placement steps, 26 (96%) prepared the tourniquet correctly, 21 (77.8%) placed it on the leg, and all the participants adjusted the band to the thickness of the injured limb and secured the windlass to the triangular flange of the device. However, only 23 (85.2%) of the participants placed it effectively. The participants, who were members of the state security forces, were able to effectively resolve a critical situation with active bleeding in a simulation scenario with a high-fidelity mannequin after completing theoretical-practical training.

Background: There are few studies that analyze ventilation volume and pressure during CPR carried out on infants. The aim of this study was to evaluate the quality of the ventilations administered using a self-inflating bag with an endotracheal tube and a face mask in manikins. Methods: a quasi-experimental simulation study with a randomized case crossover design [endotracheal tube (ET) vs. face mask (FM)] was performed. Sixty participants who were previously trained nursing students participated in the study. The estimated air volumes breathed, and the pressure generated during each ventilation were assessed and the quality of the chest compressions was recorded. Results: the ET test presented a higher percentage of ventilations that reached the lungs (100% vs. 86%; p < 0.001), with adequate volume (60% vs. 28%; p < 0.001) in comparison to FM. Both tests presented peak pressures generated in the airway greater than 30 cm H2O (ET: 22% vs. FM: 31%; p = 0.03). Conclusions: performing quality CPR ventilations on an infant model is not an easy skill for trained nursing students. Both tests presented a significant incidence of excessive peak pressure during ventilations. Specific training, focused on quality of ventilations guided by a manometer attached to the self-inflating bag, must be considered in life support training for pediatric providers.

The Arctic is warming 2-3 times faster than the global average, leading to a decrease in Arctic sea ice extent, thickness, and associated changes in sea ice structure. These changes impact sea ice habitat properties and the ice-associated ecosystems. Sea-ice algal blooms provide various algal-derived carbon sources for the bacterial and archaeal communities within the sea ice. Here, we detail the transition of these communities from winter through spring to early summer during the Norwegian young sea ICE (N-ICE2015) expedition. The winter community was dominated by the archaeon Candidatus Nitrosopumilus and bacteria belonging to the Gammaproteobacteria ( Colwellia , Kangiellaceae, and Nitrinocolaceae ), indicating that nitrogen-based metabolisms, particularly ammonia oxidation to nitrite by Cand. Nitrosopumilus was prevalent. At the onset of the vernal sea-ice algae bloom, the community shifted to the dominance of Gammaproteobacteria ( Kangiellaceae, Nitrinocolaceae ) and Bacteroidia ( Polaribacter ), while Cand. Nitrosopumilus almost disappeared. The bioinformatically predicted carbohydrate-active enzymes increased during spring and summer, indicating that sea-ice algae-derived carbon sources are a strong driver of bacterial and archaeal community succession in Arctic sea ice during the change of seasons. This implies a succession from a nitrogen metabolism-based winter community to an algal-derived carbon metabolism-based spring/ summer community.

The use of personal protective equipment (PPE) is required for the self-protection of healthcare workers during cardiopulmonary resuscitation (CPR) in patients at risk of aerosol transmission of infectious agents. The aim of this study was to analyze the impact of personal protective equipment on physiological parameters during CPR. A randomized, quasi-experimental, crossover design was used. The study was carried out in a training and simulation emergency box and the total sample consisted of 20 healthcare professionals. Two CPR tests were compared with the recommended sequence of 30 chest compressions and 2 ventilations. The duration of each test was 20 min. One of the CPR tests was carried out without using any PPE (CPR&#95;control), i.e., performed with the usual clothing of each rescuer. The other test was carried out using a CPR test with PPE (i.e., CPR&#95;PPE). The main variables of interest were: CPR quality, compressions, ventilations, maximum heart rate, body fluid loss, body temperature, perceived exertion index, comfort, thermal sensation and sweating. The quality of the CPR was similar in both tests. The maximum heart rate was higher in the active intervals (compressions + bag-valve-mask) of the test with PPE. CPR&#95;PPE meant an increase in the perceived effort, temperature at the start of the thermal sensation test, thermal comfort and sweating, as opposed to CPR performed with usual clothing. Performing prolonged resuscitation with PPE did not influence CPR quality, but caused significant physiological demands. Rescuers were more fatigued, sweated more and their thermal comfort was worse. These results suggest that physical preparation should be taken into account when using PPE and protocols for physiological recovery after use should also be established.

Objective: To assess the differences in the quality and self-perception of CPR performed with foot technique compared to the standard technique with the hands in nursing students., Methods: 65 university nursing students participated in a randomized simulation crossover design study. The participants randomly performed two CPR tests: CPR by foot and CPR by hands techniques. The compression-only protocol with a 2-min test was used with the Resusci Anne QCPR® manikin and Wireless Skill Reporter® software, both from Laerdal., Results: Participants had lower quality when doing CPR by foot (72%) than when doing standard CPR (91%) (p = 0.006). 95% of the participants indicated standard CPR as the technique of choice, while 92% indicated that they would use CPR by foot if it was not possible to perform standard technique., Conclusions: CPR quality was lower when performing foot technique, although with positive results. It would be advisable for people with acquired CPR skills to know that they can do foot compressions in situations where they cannot use their hands., Competing Interests: Declaration of Competing Interest None., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Aim: To analyse the effect of oxygen fraction reduction (O2 14%, equivalent to 3250 m) on Q-CPR and rescuers' physiological demands., Methodology: A quasi-experimental study was carried out in a sample of 9 Q-CPR proficient health care professionals. Participants, in teams of 2 people, performed 10 min CPR on a Laerdal ResusciAnne mannequin (30:2 compression/ventilation ratio and alternating roles between rescuers every 2 min) in two simulated settings: T21-CPR at sea level (FiO2 of 21%) and T14 - CPR at 3250 m altitude (FiO2 of 14%). Effort self-perception was rated from 0 (no effort) to 10 (maximum demand) points., Results: Quality of chest compressions was good and similar in both conditions (T21 vs T14). However, the percentage of ventilations with adequate tidal volume was lower in altitude than at sea level conditions (35.9 ± 25.2% vs. 54.7 ± 23.2%, p = 0.035). The subjective perception of effort was significantly higher at simulated altitude (5 ± 2) than at sea level (3 ± 2) (p = 0.038). Maximum heart rate during the tests was similar in both conditions; however, mean oxygen saturation was significantly lower in altitude conditions (90.5 ± 2.5% vs. 99.3 ± 0.5%, p < 0.001)., Conclusion: Although performing CPR under simulated hypoxic altitude conditions significantly increases the physiological demands and subjective feeling of tiredness compared to sea level CPR, trained rescuers are able to deliver good Q-CPR in such conditions, at least in the first 10 min of resuscitation., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Objective: Lifeguard teams carry out their work in extremely hot conditions in many parts of the world. The aim of this study was to analyze the impact of high temperatures on physiological parameters during cardiopulmonary resuscitation (CPR)., Method: A randomized quasi-experimental cross-over design was used to test physiological lifesaving demands (50 min acclimatization +10 min CPR) in two different thermal environments: Thermo-neutral environment (25 °C) vs Hyperthermic environment (37 °C)., Results: The data obtained from 21 lifeguards were included, this covers a total of 420 min of resuscitation. The CPR performance was constantly maintained during the 10 min. The Oxygen uptake (VO 2) ranged from 17 to 18 ml/min/kg for chest compressions (CC) and between 13 and 14 ml/min/kg for ventilations (V) at both 25 °C and 37 °C, with no significant difference between environments (p > 0.05). The percentage of maximum heart rate (%HR max) increased between 7% and 8% at 37 °C (p < 0.001), ranging between 75% and 82% of HR max. The loss of body fluids (LBF) was higher in the hyperthermic environment; LBF: (37 °C: 400 ± 187 g vs 25 °C: 148 ± 81 g, p < 0.001). Body temperature was 1 °C higher at the end of the test (p < 0.001). The perceived fatigue (RPE) increased by 37° an average of 2 points on a scale of 10 (p = 0.001)., Conclusions: Extreme heat is not a limiting factor in CPR performance with two lifeguards. Metabolic consumption is sustained, with an increase in CC, so V can serve as active rest. Nevertheless, resuscitation at 37 °C results in a higher HR, is more exhausting and causes significant loss of fluids due to sweating., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objective: To evaluate the quality of cardiopulmonary resuscitation (CPR) by lay people when guided by a mobile phone application with real-time feedback, with the comparison of three different mobile phone applications (APPs)., Design: A cross-sectional quasi-experimental study was carried out., Participants: A sample of 113 nursing students participated in the study., Interventions: Three hands-only CPR tests with continuous compressions were performed: (i)without external help; (ii)with the mobile phone turned off; and (iii)guided by APP. Three different APPs were randomly assigned (Pocket CPR®, CPR Pro®> and Massage cardiaque et DSA®). The mannequin Laerdal Resusci Anne QCPR (Stavanger, Norway) 2.0.0.14 software was used., Variables of Primary Interest: APPs used. Demographic variables characterizing the study sample., Independent Variables: mean depth, mean rate, percentage of correct hand positioning, percentage of compressions with correct re-expansion, percentage of compressions with correct depth, percentage of compressions at the correct rate, and overall quality of CPR., Results: Overall CPR quality was 33.3% ± 32.7 using Pocket CPR, 10.9% ± 22.72% using CPR Pro and 7.8% ± 9.2 using Massage cardiaque et DSA. None of the APPs produced a statistically significant improvement. The percentage of time that the resuscitator managed to maintain a correct compression rate improved when using all three APPs., Conclusions: Cardiopulmonary resuscitation guided by phone APPs did not improve the overall quality of compressions during resuscitation, though it improved the percentage of compressions performed at the correct rate., (Copyright © 2018 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.)

One of the most prominent manifestations of climate change is the changing Arctic sea-ice regime with a reduction in the summer sea-ice extent and a shift from thicker, perennial multiyear ice towards thinner, first-year ice. These changes in the physical environment are likely to impact microbial communities, a key component of Arctic marine food webs and biogeochemical cycles. During the Norwegian young sea ICE expedition (N-ICE2015) north of Svalbard, seawater samples were collected at the surface (5 m), subsurface (20 or 50 m), and mesopelagic (250 m) depths on 9 March, 27 April, and 16 June 2015. In addition, several physical and biogeochemical data were recorded to contextualize the collected microbial communities. Through the massively parallel sequencing of the small subunit ribosomal RNA amplicon and metagenomic data, this work allows studying the Arctic's microbial community structure during the late winter to early summer transition. Results showed that, at compositional level, Alpha- (30.7%) and Gammaproteobacteria (28.6%) are the most frequent taxa across the prokaryotic N-ICE2015 collection, and also the most phylogenetically diverse. Winter to early summer trends were quite evident since there was a high relative abundance of thaumarchaeotes in the under-ice water column in late winter while this group was nearly absent during early summer. Moreover, the emergence of Flavobacteria and the SAR92 clade in early summer might be associated with the degradation of a spring bloom of Phaeocystis. High relative abundance of hydrocarbonoclastic bacteria, particularly Alcanivorax (54.3%) and Marinobacter (6.3%), was also found. Richness showed different patterns along the depth gradient for prokaryotic (highest at mesopelagic depth) and protistan communities (higher at subsurface depths). The microbial N-ICE2015 collection analyzed in the present study provides comprehensive new knowledge about the pelagic microbiota below drifting Arctic sea-ice. The higher microbial diversity found in late winter/early spring communities reinforces the need to continue with further studies to properly characterize the winter microbial communities under the pack-ice.

In the Arctic Ocean ice algae constitute a key ecosystem component and the ice algal spring bloom a critical event in the annual production cycle. The bulk of ice algal biomass is usually found in the bottom few cm of the sea ice and dominated by pennate diatoms attached to the ice matrix. Here we report a red tide of the phototrophic ciliate Mesodinium rubrum located at the ice-water interface of newly formed pack ice of the high Arctic in early spring. These planktonic ciliates are not able to attach to the ice. Based on observations and theory of fluid dynamics, we propose that convection caused by brine rejection in growing sea ice enabled M. rubrum to bloom at the ice-water interface despite the relative flow between water and ice. We argue that red tides of M. rubrum are more likely to occur under the thinning Arctic sea ice regime.

Left atrium (LA) size has an important role in determining prognosis and risk stratification in hypertrophic cardiomyopathy (HCM). Cardiovascular magnetic resonance myocardial feature tracking (CMR-FT) is a novel technique for the quantification of LA function. Our aim was first to evaluate LA function by CMR-FT and volumetric analysis in patients with HCM; and secondly we sought to determine the association of LA-longitudinal strain (LA-LS) with major cardiovascular outcomes, particularly all cause mortality and heart failure. 75 patients with HCM and 75 control subjects underwent a conventional CMR study including assessment of LA function by CMR-FT (LA-LS) and volumetric analysis. A primary endpoint of all-cause mortality and secondary combined endpoint of hospital admission related to heart failure, lethal ventricular arrhythmias or cardiovascular death were defined. Compared to controls, LA-LS and all volumetric indices of LA function were significantly impaired in HCM even in patients with normal LA volume and normal LV filling pressures. LA-LS showed moderate-high correlation with LA-emptying fraction (total, active and passive LA-EF, r = 0.68, r = 0.67, r = 0.31, p < 0.001 for all) and with parameters of diastolic function (E/é, r = 0.4, p < 0.001). The age, minimum LA volume and % of LGE were independent predictors of LA-LS (p < 0.01 for all). During a mean follow-up of 3.3 ± 1.2 years LA-LS was associated with the primary (HR: 0.85 (0.73-0.98), p = 0.02) and the secondary end-point (HR: 0.88 (0.82-0.96), p = 0.003). LA-LS by CMR-FT provides accurate measurements of LA function in HCM patients. LA-LS may become a novel potential predictor of poor cardiac outcomes, particularly cardiovascular mortality and HF.

In summer 2012, Arctic sea ice declined to a record minimum and, as a consequence of the melting, large amounts of aggregated ice-algae sank to the seafloor at more than 4,000 m depth. In this study, we assessed the composition, turnover and connectivity of bacterial and microbial eukaryotic communities across Arctic habitats from sea ice, algal aggregates and surface waters to the seafloor. Eukaryotic communities were dominated by diatoms, dinoflagellates and other alveolates in all samples, and showed highest richness and diversity in sea-ice habitats (∼400-500 OTUs). Flavobacteriia and Gammaproteobacteria were the predominant bacterial classes across all investigated Arctic habitats. Bacterial community richness and diversity peaked in deep-sea samples (∼1,700 OTUs). Algal aggregate-associated bacterial communities were mainly recruited from the sea-ice community, and were transported to the seafloor with the sinking ice algae. The algal deposits at the seafloor had a unique community structure, with some shared sequences with both the original sea-ice community (22% OTU overlap), as well as with the deep-sea sediment community (17% OTU overlap). We conclude that ice-algal aggregate export does not only affect carbon export from the surface to the seafloor, but may change microbial community composition in central Arctic habitats with potential effects for benthic ecosystem functioning in the future.

Solar panels located on high (Arctic and Antarctic) latitudes combine the harshness of the climate with that of the solar exposure. We report here that these polar solar panels are inhabited by similar microbial communities in taxonomic terms, dominated by Hymenobacter spp., Sphingomonas spp. and Ascomycota. Our results suggest that solar panels, even on high latitudes, can shape a microbial ecosystem adapted to irradiation and desiccation., (© 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.)

Purpose: The aim of this study is to compare the effectiveness of active recovery in form of running or foam rolling on clearing blood lactate compared to remain sitting after a water rescue., Method: A quasi experimental cross-over design was used to test the effectiveness of two active recovery methods: foam rolling (FR) and running (RR), compared with passive recovery (PR) on the blood lactate clearance after performing a water rescue. Twelve lifeguards from Marín (Pontevedra) completed the study. The participants performed a 100-meter water rescue and a 25-minute recovery protocol., Results: The post recovery lactate levels were significantly lower for foam rolling (4.4±1.5mmol/l, P=0.005, d=0.94) and running (4.9±2.3mmol/l, P=0.027, d=1.21) compared with resting (7.2±2.5mmol/l); there was no significant difference between foam rolling and running (P=1.000)., Conclusions: We found that surf lifesavers clear out blood lactate more efficient when performing an active recovery protocol. Foam rolling is an effective method of increasing the rate of blood lactate clearance. These two recovery methods are also adequate for surf lifeguards as they do not interfere with the surveillance aspect of their job., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The Arctic icescape is rapidly transforming from a thicker multiyear ice cover to a thinner and largely seasonal first-year ice cover with significant consequences for Arctic primary production. One critical challenge is to understand how productivity will change within the next decades. Recent studies have reported extensive phytoplankton blooms beneath ponded sea ice during summer, indicating that satellite-based Arctic annual primary production estimates may be significantly underestimated. Here we present a unique time-series of a phytoplankton spring bloom observed beneath snow-covered Arctic pack ice. The bloom, dominated by the haptophyte algae Phaeocystis pouchetii, caused near depletion of the surface nitrate inventory and a decline in dissolved inorganic carbon by 16 ± 6 g C m -2 . Ocean circulation characteristics in the area indicated that the bloom developed in situ despite the snow-covered sea ice. Leads in the dynamic ice cover provided added sunlight necessary to initiate and sustain the bloom. Phytoplankton blooms beneath snow-covered ice might become more common and widespread in the future Arctic Ocean with frequent lead formation due to thinner and more dynamic sea ice despite projected increases in high-Arctic snowfall. This could alter productivity, marine food webs and carbon sequestration in the Arctic Ocean.

The Eurasian basin of the Central Arctic Ocean is nitrogen limited, but little is known about the presence and role of nitrogen-fixing bacteria. Recent studies have indicated the occurrence of diazotrophs in Arctic coastal waters potentially of riverine origin. Here, we investigated the presence of diazotrophs in ice and surface waters of the Central Arctic Ocean in the summer of 2012. We identified diverse communities of putative diazotrophs through targeted analysis of the nifH gene, which encodes the iron protein of the nitrogenase enzyme. We amplified 529 nifH sequences from 26 samples of Arctic melt ponds, sea ice and surface waters. These sequences resolved into 43 clusters at 92% amino acid sequence identity, most of which were non-cyanobacterial phylotypes from sea ice and water samples. One cyanobacterial phylotype related to Nodularia sp. was retrieved from sea ice, suggesting that this important functional group is rare in the Central Arctic Ocean. The diazotrophic community in sea-ice environments appear distinct from other cold-adapted diazotrophic communities, such as those present in the coastal Canadian Arctic, the Arctic tundra and glacial Antarctic lakes. Molecular fingerprinting of nifH and the intergenic spacer region of the rRNA operon revealed differences between the communities from river-influenced Laptev Sea waters and those from ice-related environments pointing toward a marine origin for sea-ice diazotrophs. Our results provide the first record of diazotrophs in the Central Arctic and suggest that microbial nitrogen fixation may occur north of 77°N. To assess the significance of nitrogen fixation for the nitrogen budget of the Arctic Ocean and to identify the active nitrogen fixers, further biogeochemical and molecular biological studies are needed.

We investigated 32 net primary productivity (NPP) models by assessing skills to reproduce integrated NPP in the Arctic Ocean. The models were provided with two sources each of surface chlorophyll- a concentration (chlorophyll), photosynthetically available radiation (PAR), sea surface temperature (SST), and mixed-layer depth (MLD). The models were most sensitive to uncertainties in surface chlorophyll, generally performing better with in situ chlorophyll than with satellite-derived values. They were much less sensitive to uncertainties in PAR, SST, and MLD, possibly due to relatively narrow ranges of input data and/or relatively little difference between input data sources. Regardless of type or complexity, most of the models were not able to fully reproduce the variability of in situ NPP, whereas some of them exhibited almost no bias (i.e., reproduced the mean of in situ NPP). The models performed relatively well in low-productivity seasons as well as in sea ice-covered/deep-water regions. Depth-resolved models correlated more with in situ NPP than other model types, but had a greater tendency to overestimate mean NPP whereas absorption-based models exhibited the lowest bias associated with weaker correlation. The models performed better when a subsurface chlorophyll- a maximum (SCM) was absent. As a group, the models overestimated mean NPP, however this was partly offset by some models underestimating NPP when a SCM was present. Our study suggests that NPP models need to be carefully tuned for the Arctic Ocean because most of the models performing relatively well were those that used Arctic-relevant parameters.