Search

International audience; INTRODUCTION: Traumatic cardiac arrest (TCA) guidelines emphasize specific actions that aim to treat the potential reversible causes of the arrest. The aim of this study was to measure the impact of these recommendations on specific rescue measures carried out in the field, and their influence on short-term outcomes in the resuscitation of TCA patients. METHODS: We conducted a retrospective study of all TCA patients treated in two emergency medical units, which are part of the Northern Alps Emergency Network, from January 2004 to December 2017. We categorised cases into three periods: pre-guidelines (from January 2004 to December 2007), during guidelines (from January 2008 to December 2011), and post-guidelines (from January 2012 to December 2017). Local guidelines, a physician education programme, and specific training were set up during the post-guidelines period to increase adherence to recommendations. Utstein variables, and specific rescue measures were collected: advanced airway management, fluid administration, pelvic stabilisation or tourniquet application, bilateral thoracostomy, and thoracotomy procedures. The primary endpoint was survival rate at day 30 with good neurological status (cerebral performance category scores 1 and 2) in each period, considering the pre-guidelines period as the reference. RESULTS: There were 287 resuscitation attempts in the TCA cases included, and 279 specific interventions were identified with a significant increase in the number of fluid expansions (+16%), bilateral thoracostomies (+75%), and pelvic stabilisations (+25%) from the pre- to post-guidelines periods. However, no improvement in survival over time was found. CONCLUSION: Reversible measures were applied but to a varying degree, and may not adequately capture pre-hospital performance on overall TCA survival.

It has been well established that austenite can partially transform into ferrite during thermomechanical processing. The laboratory-scale strip and plate rolling simulations in the literature suggest that both forward and backward dynamic transformation (DT) can occur above the equilibrium Ae3 temperature. In this work, a five-pass Steckel mill rolling schedule (isothermal deformation) of an X70 high Nb steel was simulated using a torsion testing machine. Four different roughing schedules with a strain of 0.4 per pass were employed at 1100 °C before the application of finishing passes. A total of five finishing passes were simulated at 900 °C with pass strains of 0.3, strain rate of 1.0 s−1, and interpass time of 10 s, followed by isothermal holding varying from 1 to 270 s. The level of the flow curves depicted activation of softening phenomena, which was shown to be the formation of DT ferrite by means of optical and scanning electron microscopy images. The volume fraction of DT ferrite increases with increasing the number of roughing passes due to retained work hardening. Moreover, the DT ferrite retransforms back into austenite during the 10 s pass interval and holding after last strains, as shown by phase fraction measurement before and after each pass. Thus, the interpass time and holding intervals after the simulations play a significant role in reducing the amount of ferrite after the process. It seems that the presence of Nb in the alloy affects both the forward and backward transformation. The present investigation can be used to estimate the amount of formed and retransformed ferrite during Steckel mill operations in order to have a better metallurgical understanding of the process. This may result in better dimensional and quality control during the manufacturing of X70 pipeline steels.

Globally, poorly managed pasture can contribute to increasing greenhouse gas (GHG) emissions. In Brazil, sustainable management systems are being proposed to reduce carbon dioxide (CO2) emissions and increase the soil C stock under degraded pasture. However, despite the potential benefits in the adoption of sustainable management systems, few studies have been carried out seeking to analyze their long-term effects on the soil C cycle. In this study, we used the DayCent model to simulate the effects of converting poorly managed pastures (PMP) to more-intensive and diversified systems of pasture management [fertilized pasture (FP), integrated crop-livestock (ICL) and integrated livestock-forest (ILF)] on long‐term soil C stocks and microbial biomass C (MBC). We also evaluated the effects of different pasture management scenarios for FP (fertilization frequency), ICL (time of implementation of the crop phase) and IFL (spacing between the tree rows). The DayCent model estimated that the conversion of PMP to FP, ICL and ILF increases the soil C stocks by 0.95, 0.04–0.70 and 0.16 Mg ha−1 yr−1, respectively. Similarly, the MBC contents also increased with conversion, mainly for ICL and ILF. In addition, the fertilization of the pasture every year (FP), the implementation of the crop phase within two years (ICL) and the spacing between the tree rows of 15 m (ILF) showed the highest soil C stocks and MBC contents. FP, ICL and IFL were also GHG sinks of 43, 57 and 116 Mg CO2eq ha−1, respectively. These results can help national initiatives associated with the recovery of degraded pasture in Brazil.

Glyphosate based herbicides (GBH) like Roundup(®) are used extensively in agriculture as well as in urban and rural settings as a broad spectrum herbicide. Its mechanism of action was thought to be specific only to plants and thus considered safe and non-toxic. However, mounting evidence suggests that GBHs may not be as safe as once thought as initial studies in frogs suggest that GBHs may be teratogenic. Here we utilize the zebrafish vertebrate model system to study early effects of glyphosate exposure using technical grade glyphosate and the Roundup(®) Classic formulation. We find morphological abnormalities including cephalic and eye reductions and a loss of delineated brain ventricles. Concomitant with structural changes in the developing brain, using in situ hybridization analysis, we detect decreases in genes expressed in the eye, fore and midbrain regions of the brain including pax2, pax6, otx2 and ephA4. However, we do not detect changes in hindbrain expression domains of ephA4 nor exclusive hindbrain markers krox-20 and hoxb1a. Additionally, using a Retinoic Acid (RA) mediated reporter transgenic, we detect no alterations in the RA expression domains in the hindbrain and spinal cord, but do detect a loss of expression in the retina. We conclude that glyphosate and the Roundup(®) formulation is developmentally toxic to the forebrain and midbrain but does not affect the hindbrain after 24 h exposure.

Sustainable intensification of livestock production systems has become a global demand. In silvopastoral systems, contrasting shading levels caused by the presence of trees interferes in the productive responses of the pasture under grazing. The environment in which plants develop in a pasture canopy is dynamic and complex due to the nature of soil-plant-animal interactions. These dynamic aspects can be rationalized, evaluated, and explained using mathematical modeling. The objective of the present study was to parameterize the APSIM-Tropical Pasture model to simulate palisadegrass [Brachiaria brizantha (Hochst A Rich) Stapf, syn. Urochloa brizantha] growth under continuous stocking and variable stocking rate, in a full sun system and in contrasting shading conditions of a silvopastoral setting with eucalyptus (Eucalyptus grandis W. Hill ex Maiden × Eucalyptus urophylla S. T. Blake). Trees were planted in triple-row groves, with three groves per 2-ha silvopasture area. The spacing between groves was 30 m, and tree density was 135 ha−1, in East-West orientation. The data used to calibrate and validate the model were collected in a 36-month experiment with full sun and shade treatments of the silvopastoral setting in Sinop, MT, Brazil. Live forage mass estimates had coefficient of determination varying between 0.76 and 0.94, Willmott agreement index ranged from 0.93 to 0.96, and root mean square error between 275 and 610 kg DM ha−1. The APSIM-Tropical Pasture model can simulate Marandu palisadegrass growth under continuous stocking with variable stocking rate, but improvements are needed to better simulate the effect of N fertilizations in different periods on growth. The model can simulate pasture growth under shading levels but our simulations did not consider competition for soil moisture, which should be considered in the future, since it can be an important factor for other silvopastoral designs or microclimatic conditions.

Agroforestry systems can minimize heat stress and improve cattle welfare, but the influence of the forest component in microclimatic changes in the southern Amazon remains unclear. This study aimed to compare the thermal comfort indices in grass monoculture and integrated systems. The three systems were pasture under full sunlight (PFS), integrated (triple-row) livestock-forestry (ILFT), and integrated (single-row) livestock-forestry (ILFs), across four seasons, for two years, from June 2017 to June 2019. We assessed photosynthetically active radiation (PAR), air temperature, relative humidity, black globe temperature, and wind speed. Thermal comfort indices such as temperature-humidity index (THI), black globe temperature-humidity index (BGHI), and radiant thermal load (RTL) were calculated based on microclimate data daily-collected from 8:00 to 16:00. The ILFT mean THI (76.8) was slightly lower than ILFS and PFS. The BGHI and RTL values decreased as shading increased (PFS > ILFs > ILFT). The most challenging heat stress conditions for grazing animals occurred predominately during winter and autumn. In conclusion, the presence of trees in pastures of the southern Amazon improved the microclimate and, consequently, the thermal comfort indices. Agroforestry systems can foster an environment with a more suitable thermal comfort or less restrictive to animal performance, which contribute to mitigating global climate change for forage-livestock systems in Brazilian Amazon.

Lead has been utilized throughout history and is widely distributed and mobilized globally. Although lead in the environment has been somewhat mitigated, the nature of lead and its extensive uses in the past prohibit it from being completely absent from our environment and exposure to lead is still a public health concern. Most studies regarding lead toxicity have focused on the brain. However, little is found in the literature on the effects of lead in other tissues. Here, we utilize the zebrafish model system to investigate effects of lead exposure during early developmental time windows at 24, 48 and 72 h post fertilization in the body. We analyze whole body, notochord and somatic muscle changes, vascular changes of the body, as well as motor neuron alterations. We find lead exposure induces a curved body phenotype with concomitant changes in somite length, decreased notochord staining and abnormal muscle staining using live and in situ approaches. Furthermore, altered vasculature within the somatic regions, loss and/or alternations of motor neuron extension both dorsally and ventrally from the spinal cord, loss of Rohon-Beard sensory neurons, and increased areas of apoptosis were found. We conclude that lead is developmentally toxic to other areas of the developing embryo, not just the brain.

Warm-season grasses are economically important for cattle production in tropical regions, and tools to aid in management and research of these forages would be highly beneficial. Crop simulation models synthesize numerous physiological processes and are important research tools for evaluating production of warm-season grasses. This research was conducted to adapt the perennial CROPGRO Forage model to simulate growth of the tropical species palisadegrass [ Brachiaria brizantha (A. Rich.) Stapf. cv. Xaraes] and to describe model adaptation for this species. In order to develop the CROPGRO parameters for this species, we began with values and relationships reported in the literature. Some parameters and relationships were calibrated by comparison with observed growth, development, dry matter accumulation and partitioning during a 2-year experiment with Xaraes palisadegrass in Piracicaba, SP, Brazil. Starting with parameters for the bahiagrass ( Paspalum notatum Flugge) perennial forage model, dormancy effects had to be minimized, and partitioning to storage tissue/root decreased, and partitioning to leaf and stem increased to provide for more leaf and stem growth and less root. Parameters affecting specific leaf area (SLA) and senescence of plant tissues were improved. After these changes were made to the model, biomass accumulation was better simulated, mean predicted herbage yield per cycle was 3573 kg ha −1 , with a RMSE of 538 kg DM ha −1 ( D -Stat = 0.838, simulated/observed ratio = 1.028). The results of the adaptation suggest that the CROPGRO model is an efficient tool to integrate physiological aspects of palisadegrass and can be used to simulate growth.