Megaripple Migration on Mars.

Aeolian megaripples, with 5- to 50-m spacing, are abundant on the surface of Mars. These features were repeatedly targeted by high-resolution orbital images, but they have never been observed to move. Thus, aeolian megaripples (especially the bright-toned ones often referred as Transverse Aeolian Ridges-TARs) have been interpreted as relict features of a past climate. In this report, we show evidence for the migration of bright-toned megaripples spaced 1 to 35 m (5 m on average) in two equatorial areas on Mars indicating that megaripples and small TARs can be active today. The moving megaripples display sand fluxes that are 2 orders of magnitudes lower than the surrounding dunes on average and, unlike similar bedforms on Earth, can migrate obliquely and longitudinally. In addition, the active megaripples in the two study areas of Syrtis Major and Mawrth Vallis show very similar flux distributions, echoing the similarities between dune crest fluxes in the two study areas and suggesting the existence of a relationship between dune and megaripple fluxes that can be explored elsewhere. Active megaripples, together with high-sand flux dunes, represent a key indicator of strong winds at the surface of Mars. A past climate with a denser atmosphere is not necessary to explain their accumulation and migration.

Antimicrobial resistance in N'Djamena (Chad): Four-year experience of the French Forward Medical and Surgical Team engaged in the "Barkhane Operation".

OBJECTIVES: Knowledge of local antimicrobial resistance (AMR) patterns is required for effective empirical treatment of bacterial diseases. Very little is known about current resistance patterns of common pathogenic bacteria in the African region and particularly in the Sahel region. We aimed to describe the local bacterial epidemiology and to determine whether French recommendations for empirical treatment could be implemented. PATIENTS AND METHODS: We performed a single-center observational study. Data was collected retrospectively from the Forward Medical and Surgical Center (FFMSC) bacterial database from January 2015 to December 2018. All bacteriological analyses, negative or positive, were included. RESULTS: A total of 2194 samples were analyzed. Infectious diseases were urinary tract infections (20.8%), bone and joint infections (20.4%), skin infections of chronic wounds (13.4%), soft tissue abscesses (13%), and gastroenteritis (10.8%). The most frequent infections were enterobacterial infections (43.6%) and staphylococcal infections (31.1%). The prevalence of AMR was 32.1%. Significantly more ESBL-producing bacteria (41.3%) were observed in the Chadian population than in the French population in N'djamena (6.3%) (P<0.001). CONCLUSIONS: We reported a high rate of ESBL-producing bacteria in N'Djamena. The use of empirical antibiotic therapies in the FFMSC may thus be questioned: French recommendations cannot be implemented in such setting and the use of carbapenems or new anti-ESBL antibiotics should be considered. Prospective studies are required to conclude.

Impact of high-dose norepinephrine during intra-hospital damage control resuscitation of traumatic haemorrhagic shock: A propensity-score analysis.

INTRODUCTION: The use of norepinephrine (NE) during uncontrolled haemorrhagic shock (HS) has mostly been investigated in experimental studies. Clinical data including norepinephrine dose and its impact on fluid resuscitation and organ function are scarce. We hypothesized that there is great variability in NE use and that high doses of NE could lead to increased organ dysfunction as measured by the sequential organ failure assessment (SOFA). METHOD: We included patients with HS (systolic blood pressure < 90 mmHg in severely injured patients) who required haemostasis surgery and a transfusion of more than 4 packed red blood cells (PRBC) in the first 6 h of admission and the used of norepinephrine infusion to maintain the blood pressure goal, between admission and the end of haemostasis surgery in a prospective trauma database. A ROC curve determined that, using Youden's criterion, a dose of NE ≥ 0.6 µg/kg/min was the optimal threshold associated with intrahospital mortality. Patients were compared according to this threshold in a propensity score (PS) model. In a generalized linear mixed model, we searched for independent factors associated with a SOFA ≥ 9 at 24 h RESULTS: A total of 89 patients were analysed. Fluid infusion rate ranged from 1.43 to 57.9 mL/kg/h and norepinephrine infusion rate from 0.1 to 2.8 µg/kg/min. The HDNE group received significantly less fluid than the LDNE group. This dose is associated with a higher SOFA score at 24h: 9 (7-10) vs. 7 (6-9) (p = 0.003). Factors independently associated with a SOFA score ≥ 9 at 24 h were maximal norepinephrine rate ≥ 0.6 µg/kg/min (OR 6.69, 95% CI 1.82 - 25.54; p = 0.004), non-blood resuscitation volume < 9 mL/kg/h (OR 3.98, 95% CI 1.14 - 13.95; p = 0.031) and lactate at admission ≥ 5 mmol/L (OR 5.27, 95% CI 1.48 - 18.77; p = 0.010) CONCLUSION: High dose of norepinephrine infusion is associated with deleterious effects as attested by a higher SOFA score at 24 h and likely hypovolemia as measured by reduced non-blood resuscitation volume. We did not find any significant difference in mortality over the long term.

A rare Foreign Body in the bladder: a surgical dressing as a bladder stone.

We report an unusual case of a foreign body removed from the urinary bladder of an 11-year-old boy, which had mimicked a recurrent bladder stone. The diagnosis was suspected by ultrasound. As the clinical presentation appeared typical, no other examination was performed. Open surgery revealed that this foreign body was a surgical dressing forgotten during the first surgery eight years earlier. The absence of clinical evidence or infectious complications related to this foreign body over such a long period was surprising.

Screening, plant growth promotion and root colonization pattern of two rhizobacteria (Pseudomonas fluorescens Ps006 and Bacillus amyloliquefaciens Bs006) on banana cv. Williams (Musa acuminata Colla).

Banana is the second largest export crop in Colombia. To meet the demand of international markets, high amounts of chemical fertilizers are required, which represent high costs and can be hazardous to the environment. Plant growth promoting rhizobacteria (PGPR) can, at least partially, replace chemical fertilizers. In this paper, we evaluated the effect of nine PGPR of the genera Bacillus and Pseudomonas on banana growth. Banana seedlings were produced through tissue culture and acclimatized in the greenhouse core. Plants were inoculated with the rhizobacteria and growth parameters (plant height, leaf number, leaf area, pseudostem thickness, root and shoot fresh weight, root and shoot dry weight) were assessed after 55 days. The two best performing PGPR, Bs006 and Ps006 previously identified as Bacillus amyloliquefaciens and Pseudomonas fluorescens, respectively, promoted banana growth similarly or even slightly superior to 100% chemical fertilization, and were selected for further characterization of root colonization by both eletron microscopy and confocal microscopy of fluorescence in situ hybridization (FISH)-stained root tissues. Both P. fluorescens Ps006 and B. amyloquifaciens Bs006 showed ability to colonize banana roots, but Bs006 appeared faster than Ps006 in the colonization dynamics. This work demonstrated that inoculation of rhizobacteria Bacillus amyloliquefaciens Bs006 and Pseudomonas fluorescens Ps006 could partially replace the chemical fertilization of tissue cultured banana plants, and therefore could be used for the formulation of a new biofertilizer.

Video analysis of acute injuries and referee decisions during the 24th Men's Handball World Championship 2015 in Qatar.

Although handball is a contact sport with a high risk of acute match injuries, their mechanisms have not yet been investigated. We aimed to describe the mechanisms of acute match injuries in elite male handball and evaluate referee performance in injury situations. Based on injury surveillance from the 24th Men's Handball World Championship 2015 in Qatar, injury situations and the referee decisions were identified on video footage. A total of 55 injury situations and 37 referee decisions were included for analysis. The injury situations were analyzed individually by five handball experts, followed by a consensus meeting. An expert referee panel performed individual blinded evaluation of the referee decisions, followed by an online consensus meeting. Injuries were evenly distributed among attackers (n = 29) and defenders (n = 26). The most frequent injury cause was contact trauma due to a tackle (n = 27). At the time of injury, attackers were most frequently performing a jump shot (n = 9), while defenders were completing a tackle (n = 10). Defenders most commonly tackled the throwing arm (n = 7) or toward the head/face region (n = 6) of injured attackers, while attackers most frequently hit injured defenders with the knee during jump shots (n = 5). Agreement between the referees and the expert panel was weak (kappa: 0.22, 95% CI 0.07 to 0.36), with substantially more lenient rule interpretation by the referees. Our results suggest that stricter refereeing and rule amendments should be considered to prevent acute match injuries in elite handball, especially in relation to tackling episodes when an attacker is performing a jump shot.

Effects of vibration-induced fatigue on the H-reflex.

Vibration exercise (VE) has been suggested as an effective training for improving muscle strength and coordination. However, the underlying physiological adaptation processes are not yet fully understood, limiting the development of safe and effective exercise protocols. To better understand the neuromuscular responses elicited by VE, we aimed at investigating the acute effects of superimposed vibration on the Hoffmann reflex (H-reflex), measured after fatiguing exercise. Twenty-five volunteers performed four isometric contractions of the right Flexor Carpi Radialis (FCR) with baseline load at 80% of their maximal voluntary contraction (MVC), both with no vibration and with superimposed vibration at 15, 30, and 45 Hz. Fatigue was estimated by MVC test and estimation of electromyographic spectral compression. H-reflex suppression was estimated as the relative decrease after exercise. Our results show that fatiguing exercise determined a decrease in H-reflex amplitude compared to rest condition while vibration determined a lower H-reflex suppression as compared to no vibration. The superimposition of 30-Hz vibration determined the largest acute reduction in force generating capacity (36 N, p < 0.05) and the lowest H-reflex suppression (20%, p < 0.05). These results suggest VE to be particularly suitable in rehabilitation programs for rapid restoration of muscle form and function after immobilization periods.

Emergency Medical Service Information System:the ARES 118 experience.

BACKGROUND: In this paper we describe ARES 118, the prehospital Emergency Medical Service of the Region Lazio, Italy, focusing on its data system used to populate a data warehouse and to create ad hoc reports. ARES 118 is a regional public mono-specialized health company, established in 2004, that manages the emergency care throughout the Region Lazio. METHODS: Being a peculiar company in its kind, and being the first experience of this kind in Italy, ARES 118 has begun to equip itself, in an autonomous way, with a corporate information system, starting from what already existed as data collection from the individual provincial operating Centers and then by activating a unique information system at a regional and company level by deploying a data warehouse. All operations were carried out using open source software. RESULTS: Currently, ARES 118 is equipped with a business information system that enables data collection with its storage, management and processing of the same in fairly and easy way. The system allows the production of specific reports and measures modulated on the user requests in order to highlight the different aspects of the activity. CONCLUSIONS: The production of ad hoc reports, with the possibility of developing specific indicators, allows the identification and analysis of critical areas/processes in order to implement any corrective actions and monitor the effectiveness of the sam.

[Inferior myocardial infarction complicated by complete heart block and cardiac arrest following a gadolinium injection: A case of Kounis syndrome]. / Infarctus du myocarde inférieur compliqué de bloc auriculo-ventriculaire complet et d'arrêt cardiocirculatoire dans les suites d'une injection de gadolinium : à propos d'une observation de syndrome de Kounis.

Kounis syndrome is an allergic acute coronary syndrome. It occurs on healthy or pathological arteries. Its complications, although often benign, can lead to cardiac arrest and death. Its triggering factors are multiple and include contrast products used in diagnostic imaging. We report the case of an 81 years old patient affected by hepatocellular carcinoma, who presented a type 2 Kounis syndrome with inferior myocardial infarction, complicated by cardiac arrest related to complete heart block following a gadoteric acid injection.

Characterization of muscle oxygenation response to vascular occlusion: implications for remote ischaemic preconditioning and physical Performance.

Remote ischaemic preconditioning is a non-invasive intervention with potential to protect a number of organs against ischaemia-reperfusion injury and possibly improve athletic performance. Little mechanistic evidence exists to support either limb choice or cuff inflation pressure that is most effective. This preliminary study aimed to establish the dose-response effect of different occlusion pressures on skeletal muscle oxygenation and blood flow in healthy males (n = 6). In a randomized controlled crossover study, cuff inflation pressures (140,160 and 180 mmHg) were used to induce limb ischaemia (× 3 cycles of 5-min) in upper (UL) and lower (LL) limbs on three separate occasions. Muscle oxygenation and blood flow properties of UL (flexor carpi ulnaris) and LL (vastus lateralis) were assessed using near infrared spectroscopy. Higher deoxyhaemoglobin (ΔHHb) values were consistently observed in UL (versus LL; P<0·05), no difference between pressures. Occlusion at 140 mm Hg failed to elicit decreases in tissue oxyhaemoglobin (ΔHbO2 ) from resting baseline (UL and LL), with significant HbO2 decreases only observed at 180 mmHg in LL (P<0·05). Increases in ΔHbO2 and muscle oxygenation index (Hbdiff ) above baseline were observed with cuff deflation, lasting up to 15 min into recovery in LL irrespective of occlusion pressure (P<0·05). Muscle oxygenation properties are influenced by choice of limb occluded and findings show that tissue ischaemia can be induced at much lower absolute pressures than traditionally used in RIPC studies. Blood flow and muscle oxygenation may be enhanced for at least 15 min following the last occlusion.

Repeated change-of-direction test for collegiate male soccer players.

AIM: The aim of the study was to investigate the applicability of a repeated change-of-direction (RCoD) test for NCAA Division-I male soccer players. METHODS: The RCoD test consisted of 5 diagonal direction changes per repetition with a soccer ball to be struck at the end. Each player performed 15 repetitions with approximately 10 seconds to jog back between repetitions. Data were collected in two sessions. In the first session, 13 players were examined for heart rate responses and blood lactate concentrations. In the second session, 22 players were examined for the test's ability to discriminate the primary from secondary players (78.0±16.1 and 10.4±13.3 minutes per match, respectively). RESULTS: Heart rate data were available only from 9 players due to artifacts. The peak heart rate (200.2±6.6 beats∙min-1: 99.9±3.0% maximum) and blood lactate concentration (14.8±2.4 mmol∙L-1 immediately after) resulted in approximately 3.5 and 6.4-fold increases from the resting values, respectively. These values appear comparable to those during intense periods of soccer matches. In addition, the average repetition time of the test was found to discriminate the primary (4.85±0.23 s) from the secondary players (5.10±0.24 s) (P=0.02). CONCLUSION: The RCoD test appears to induce physiological responses similar to intense periods of soccer matches with respect to heart rate and blood lactate concentration. Players with better average repetition times tend to be those who play major minutes.

Combination of external load and whole body vibration potentiates the GH-releasing effect of squatting in healthy females.

In recent years, whole body vibration (WBV) has become an efficient complement or alternative to resistance training. Very limited data on the effects of different WBV protocols on anabolic hormones are available. In this study, we compared the growth hormone (GH), blood lactate (LA), and cortisol responses to different protocols involving WBV. Six healthy women recreationally active performed 10 sets of 12 dynamic squats in the following conditions: squatting alone (S), squatting+vibration (SV), squatting+external load (SE), and squatting+external load+vibration (SEV). All responses at the different stimuli determined acute increases in GH, cortisol, and LA. In particular, GH secretion significantly increased in all 4 conditions immediately after the exercise session compared to other time points. Furthermore, a significantly larger increase was identified following SEV as compared to the other conditions. Cortisol concentrations significantly decreased after S, SV and SE whereas they increased significantly following SEV. LA peaks occurred immediately at the end of each condition. However it reached statistical significance only following SEV. The results of our study demonstrate that the combination of squatting+external load+vibration (SEV) could represent the most suitable modality to potentiate the somatotropic function and, indirectly, to obtain an increase in muscle strength and positive changes in the body composition. Further studies are necessary in order to determine the chronic effects of this exercise modality on the hormonal profile.

Activated zeolite--suitable carriers for microorganisms in anaerobic digestion processes?

Plant cell wall structures represent a barrier in the biodegradation process to produce biogas for combustion and energy production. Consequently, approaches concerning a more efficient de-polymerisation of cellulose and hemicellulose to monomeric sugars are required. Here, we show that natural activated zeolites (i.e. trace metal activated zeolites) represent eminently suitable mineral microhabitats and potential carriers for immobilisation of microorganisms responsible for anaerobic hydrolysis of biopolymers stabilising related bacterial and methanogenic communities. A strategy for comprehensive analysis of immobilised anaerobic populations was developed that includes the visualisation of biofilm formation via scanning electron microscopy and confocal laser scanning microscopy, community and fingerprint analysis as well as enzyme activity and identification analyses. Using SDS polyacrylamide gel electrophoresis, hydrolytical active protein bands were traced by congo red staining. Liquid chromatography/mass spectroscopy revealed cellulolytical endo- and exoglucanase (exocellobiohydrolase) as well as hemicellulolytical xylanase/mannase after proteolytic digestion. Relations to hydrolytic/fermentative zeolite colonisers were obtained by using single-strand conformation polymorphism analysis (SSCP) based on amplification of bacterial and archaeal 16S rRNA fragments. Thereby, dominant colonisers were affiliated to the genera Clostridium, Pseudomonas and Methanoculleus. The specific immobilisation on natural zeolites with functional microbes already colonising naturally during the fermentation offers a strategy to systematically supply the biogas formation process responsive to population dynamics and process requirements.

Visual skills and playing positions of Olympic field hockey players.

Many sports require fine spatiotemporal resolution for optimal performance. Previous studies have compared anticipatory skills and the decision-making process in athletes; however, there is little information on visual skills of elite athletes, particularly hockey players. To assess visual skills of Olympic hockey players and analyze differences by playing position, and to analyze improvement of visual skills after training, 21 Olympic field hockey players were pre- and post-tested on 11 visual tasks following a 10-wk. visual training program consisting of computer-based visual exercises. There were no mean differences at pre-test between players of different positions, suggesting that performance on these visual skills was independent of playing position. However, after training, an improvement was seen in all players (when scores were averaged across all 11 visual tasks) with goalkeepers improving significantly more than any other position. This suggests the possibility of improving visual skills even in an elite population.

Analysis of muscle fatigue induced by isometric vibration exercise at varying frequencies.

An increase in neuromuscular activity, measured by electromyography (EMG), is usually observed during vibration exercise. The underlying mechanisms are however unclear, limiting the possibilities to introduce and exploit vibration training in rehabilitation programs. In this study, a new training device is used to perform vibration exercise at varying frequency and force, therefore enabling the analysis of the relationship between vibration frequency and muscle fatigue. Fatigue is estimated by maximum voluntary contraction measurement, as well as by EMG mean-frequency and conduction-velocity analysis. Seven volunteers performed five isometric contractions of the biceps brachii with a load consisting of a baseline of 80% of their maximum voluntary contraction (MVC), with no vibration and with a superimposed 20, 30, 40, and 50 Hz vibrational force of 40 N. Myoelectric and mechanical fatigue were estimated by EMG analysis and by assessment of the MVC decay, respectively. A dedicated motion artifact canceler, making use of accelerometry, is proposed to enable accurate EMG analysis. Use of this canceler leads to better interpolation of myoelectric fatigue trends and to better correlation between mechanical and myoelectric fatigue. In general, our results suggest vibration at 30 Hz to be the most fatiguing exercise. These results contribute to the analysis of vibration exercise and motivate further research aiming at improved training protocols.

Electromyographic assessment of muscle fatigue during isometric vibration training at varying frequencies.

Resistance exercise is essential to improve or maintain muscle performance. Vibration training has been suggested as an alternative option for muscle conditioning, aiming especially at improving muscle strength and power. Several studies link the effects of vibration training to enhanced neuromuscular stimulation, measured by electromyography (EMG) and typically ascribed to involuntary reflex mechanisms. However, the underlying mechanisms are still unclear, limiting the use of vibration training. This paper proposes additional methods to analyze the mechanisms involved in vibration training. A dedicated measurement setup was realized to relate vibration parameters to muscle fatigue in the biceps brachii. Fatigue is estimated by EMG mean frequency and conduction velocity assessments as well as by maximum voluntary contraction (MVC) force measurements. A modified maximum likelihood algorithm is proposed for the conduction velocity estimation based on high-density EMG recording. Five volunteers performed four isometric contractions of 50 s at 80% MVC with no vibration (control) and with superimposed vibration at 20, 30, and 40 Hz. Fatigue was estimated from the decay of force, EMG mean frequency, and EMG conduction velocity. 30-Hz vibrations represented the most fatiguing stimulus. Our preliminary results also show a better correlation between force and conduction velocity decay than between force and mean frequency decay, indicating the former as a better EMG indicator of fatigue. The proposed methods provide important advancements for the analysis of vibration exercise and guidance towards the definition of optimal training protocols.