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The population dynamics of shrimp Pleoticus muelleri was used as a model to verify if the trend of continuous reproduction periodicity, shorter body size and longevity, and early sexual maturity found in tropical regions is corroborated in upwelling regions. Shrimps were sampled in a region under the influence of upwelling (northern coast of Rio de Janeiro State, Brazil). Characteristics of bottom water were registered, and shrimps were measured (carapace length – CL) and classified by sex and gonadal development stages. Reproduction was seasonal, from September to December, and favoured by water mass intrusions of low temperatures and high chlorophyll concentrations. The greatest number of reproductive females preceded periods with the highest chlorophyll concentrations in the water column (cross-correlation; P < 0.05, lag (month) = −3, r = 0.50), suggesting greater developmental success of larval stage due to increase of food availability. Von Bertalanffy growth models resulted in asymptotic carapace length estimates of CL∞ = 40.21 mm and CL∞ = 36.78 mm for females and males, respectively. The reproductive and growth characteristics of the P. muelleri population studied herein were similar to that of populations from higher latitudes, demonstrating that the latitudinal pattern rule cannot be applied in regions influenced by an upwelling phenomenon.
The aim of this study was to compare the effects of cowpea green manure and inorganic nitrogen (N) fertilizers on yields of winter wheat and soil emissions of nitrous oxide (N2O). The comparisons included cowpea grown solely as green manure where all biomass was terminated at maturity by tillage, summer fallow treatments with 90 kg N ha−1 as urea (90-N), and no fertilization (control) at planting of winter wheat. Fluxes of N2O were measured by closed chamber methods after soil incorporation of cowpea in autumn (October–November) and harvesting of winter wheat in summer (June–August). Growth and yields of winter wheat and N concentrations in grain and straw were also measured. Cowpea produced 9.5 Mg ha−1 shoot biomass with 253 kg N ha−1 at termination. Although soil moisture was favorable for denitrification after soil incorporation of cowpea biomass, low concentrations of soil mineral N restricted emissions of N2O from cowpea treatment. However, increased concentrations of soil mineral N and large rainfall-induced emissions were recorded from the cowpea treatment during summer. Growth of winter wheat, yield, and grain N concentrations were lowest in response to cowpea treatment and highest in 90-N treatment. In conclusion, late terminated cowpea may reduce yield of winter wheat and increase emissions of N2O outside of wheat growing seasons due to poor synchronization of N mineralization from cowpea biomass with N-demand of winter wheat.
The savannah enclaves (i.e. patches) in the southern Brazilian Amazonia are among the most threatened and poorly surveyed sites in Amazonia. As part of an extensive mammal survey, we set camera traps in three of these savannah enclaves. We obtained 23 independent records of pampas deer Ozotoceros bezoarticus, a medium sized Neotropical cervid that is strongly associated with open habitats and categorized as Vulnerable on the Brazilian Red List of threatened species. These savannah enclaves with confirmed populations of pampas deer lie outside the species’ previously presumed historical range and are at least 350 km from any known extant population. Together, these savannah enclaves add c. 4,000 km2 to the pampas deer's currently known range. The small pampas deer populations in these enclaves are probably isolated by a matrix of Amazon forest, raising questions about spatial genetic structure and meta-population dynamics, and making them vulnerable to local extinction. We highlight the need for further studies, particularly genetic, to assess the conservation status of these populations, the results of which could potentially inform management decisions in other areas of the heavily fragmented range of this species.
Prehospital identification of large vessel occlusion (LVO) stroke may expedite treatment by direct transport to comprehensive stroke centers (CSCs) with endovascular capabilities. The Cincinnati Prehospital Stroke Scale (CPSS) is commonly used for prehospital stroke detection. We aimed to assess whether (1) a high CPSS score can identify LVO and (2) an Emergency Medical Service (EMS) redirection protocol based on high CPSS accelerated endovascular treatment (EVT).
A retrospective comparison of patients transported by EMSs for suspected stroke to a high-volume CSC over a 16-month period, before and after implementation of an EMS redirection protocol based on high CPSS score (3/3). Charts were reviewed to determine the presence of LVO. Time to EVT and 3-month outcomes were compared before and after implementation.
A prehospital CPSS 3/3 score was found in 223 (59%) patients, demonstrating positive and negative predictive values for LVO of 29% and 94%, respectively. CPSS-based EMS redirection increased the proportion of EVT performed after direct transport to CSC [before: 21 (36%), after: 45 (63%), p < 0.01] and decreased median first door-to-groin puncture time by 28 minutes [109 (interquartile range (IQR) 64–116) versus 81 (IQR 56–130), p = 0.03]. At 3 months, the proportion of patients achieving functional independence (modified Rankin score 0–2) went from 20/57 (35%) to 29/68 (43%) (p = 0.39) following implementation.
CPSS-based EMS redirection accelerated identification of LVO strokes in the out-of-hospital setting and decreased time to EVT. Nevertheless, this protocol was also associated with high rates of non-LVO stroke. Impact on clinical outcomes should be evaluated in a larger cohort.
In this study, we measured nitrous oxide (N2O) emissions from plots of fall-planted hairy vetch (HV, Vicia villosa) grown as a green nitrogen (N) source for following summer forage crabgrass (Digitaria sanguinalis). Two treatments were compared: (i) HV grown solely as green manure where all biomass was incorporated by tillage, and (ii) harvesting of aboveground HV biomass prior to planting of crabgrass. Fluxes of N2O were measured with closed chamber systems on 27 dates during a 2-month growth period of crabgrass after the termination of HV in early May. At termination, the average aboveground biomass yield of HV was 4.6 Mg ha−1 with 146 kg N ha−1 content. The N2O emissions were as high as 66 g N2O-N ha−1 day−1 on day 1 after HV incorporation, but reached close to zero within a week. Emissions of N2O increased with subsequent rainfall and irrigation events from both treatments but emission peaks were not observed during the rapid growth of crabgrass. Two-month cumulative emission of N2O (mean ± s.e., n = 4) from HV incorporated plots (921 ± 120 g N2O-N ha−1) was three times (P < 0.05) of HV harvested plots (326 ± 30 g N2O-N ha−1). However, crabgrass biomass yields, N concentrations and total biomass N uptake were decreased significantly by harvesting HV. In conclusion, the results suggested that whereas removal of HV biomass for use as forage may significantly reduce N2O emissions, quantity and quality of the following recipient crops may be constrained.
Tuberculosis (TB) is still a major public health problem in many countries, including Brazil. Primary health care (PHC) services are a set of important services with infrastructure and resources to diagnose, treat, and cure several diseases, including the TB.
The aim of this study is to analyse aspects of the facility infrastructure of Brazilian PHC, regarding the control and treatment of TB from a countrywide perspective.
This is a cross-sectional study based on PHC services. Data were collected from 38,812 health centres and were assessed by means of the National Program for Improving Access and Quality Primary Care. The outcome was obtained by the presence and availability of the following infrastructure items: air circulation in the consultation room, refrigerator, individual protective equipment, plastic jar for sputum examination, and TB notification form of the primary care information system. Poisson regression was used to calculate the prevalence ratio.
Of the 38,812 evaluated centres, only 1628 (4.2%) presented a positive result regarding the outcome. Primary health centres, among all types of centres, presented the highest quality of facility infrastructure for TB control. Centres with large workloads, as well as those that presented a list of offered services and a welcoming consulting room, also presented the highest quality infrastructure. The present study shows that major improvements should be made to the infrastructure to reach a satisfactory TB control in Brazil.
Permafrost occupies 20 million square kilometres of Earth’s high-latitude and high-altitude landscapes. These regions are sensitive to climate change and human activities; hence, permafrost research is of considerable scientific and societal importance. However, the results of this research are generally not known by the general public. Communicating scientific concepts is an increasingly important task in the research world. Different ways to engage learners and incorporate narratives in teaching materials exist, yet they are generally underused. Here we report on an international scientific outreach project called “Frozen-Ground Cartoons”, which aims at making permafrost science accessible and fun for students, teachers, and parents through the creation of comic strips. We present the context in which the project was initiated, as well as recent education and outreach activities. The future phases of the project primarily involve a series of augmented reality materials, such as maps, photos, videos, and 3D drawings. With this project we aim to foster understanding of permafrost research among broader audiences, inspire future permafrost researchers, and raise public and science community awareness of polar science, education, outreach, and engagement.
The X-Shooter Spectral Library (XSL) contains more than 800 spectra of stars across the color-magnitude diagram, that extend from near-UV to near-IR wavelengths (320-2450 nm). We summarize properties of the spectra of O-rich Long Period Variables in the XSL, such as phase-related features, and we confront the data with synthetic spectra based on static and dynamical stellar atmosphere models. We discuss successes and remaining discrepancies, keeping in mind the applications to population synthesis modeling that XSL is designed for.
The aim of this study was to establish a functional freezing–thawing protocol for epididymal sperm of collared peccaries (Pecari tajacu L., 1758) by comparing different extenders. The epididymal sperm from 12 sexually mature males was recovered by retrograde flushing using Tris-based or coconut water-based (ACP®-116c) extenders. After initial evaluation, samples were diluted and frozen with the same extenders to which 20% egg yolk and 6% glycerol were added. After 2 weeks, thawing was performed at 37°C/60 s and sperm motility, vigour, morphology, functional membrane integrity, sperm viability, sperm plasma membrane integrity, and a computer-assisted semen analysis (CASA) were assessed. In addition, to evaluate the survival of frozen–thawed sperm, a thermal resistance test (TRT) was executed. Samples preserved using Tris were in better condition compared with those preserved using ACP®, showing higher values for most assessments performed, including CASA and the TRT (P<0.05). After determining Tris to be the better of the two extenders, additional samples were thawed using different thawing rates (37°C/60 s, 55°C/7 s, 70°C/8 s). Sperm thawed at 37°C/60 s had the greatest preservation (P<0.05) of viability (54.1 ± 5.9%) and functional membrane integrity (43.2 ± 5.4%), and had higher values for various CASA parameters. In conclusion, we suggest the use of a Tris-based extender added to egg yolk and glycerol for the cryopreservation of epididymal sperm obtained from collared peccaries. In order to achieve better post-thawing sperm quality, we suggest that samples should be thawed at 37°C/60 s.
We present an application of scanning electron diffraction for the characterisation of crystal defects in olivine, quartz and phase A (a high pressure hydrated phase). In this mode, which takes advantage of the ASTAR™ module from NanoMEGAS, a slightly convergent probe is scanned over the sample with a short acquisition time (a few tens of ms) and the spot patterns are acquired and stored for further post-processing. Originally, orientation maps were constructed from automatic indexing at each probe location. Here we present another application where images are reconstructed from the intensity of diffraction spots, producing either so-called ‘virtual’ bright- or dark-field images. We show that these images present all the characteristics of contrast (perfect crystal or defects) of conventional transmission electron microscopy images. Data are acquired with a very short time per probe location (a few tens of milliseconds), this technique appears very attractive for the characterisation of beam-sensitive materials. However, as the acquisition is done at a given orientation, fine tuning of the diffraction conditions at a given location for each reflection is not possible. This might present a difficulty for some precise, quantitative contrast analysis.
Introduction: Pulse check by manual palpation (MP) is an unreliable skill even in the hands of healthcare professionals. In the context of cardiac arrest, this may translate into inappropriate chest compressions when a pulse is present, or conversely omitting chest compressions when one is absent. To date, no study has assessed the utility of B-mode ultrasound (US) for the detection of a carotid pulse. The primary objective of this study is to assess the time required to detect a carotid pulse in live subjects using US compared to the standard MP method. Methods: This is a prospective randomized controlled cross-over non-inferiority trial. Health care professionals from various backgrounds were invited to participate. They attended a 15 minute focused US workshop on identification of the carotid pulse. Following a washout period, they were randomized to detect a pulse in live subjects either by MP first or by US first. Both pulse check methods were timed for each participant on 2 different subjects. The primary outcome measure was time to carotid pulse detection in seconds. Secondary outcome measures included comfort levels of carotid pulse detection measured on a 100mm visual analog scale (VAS), and rates of prolonged pulse checks (greater than 5 or 10 seconds) for each technique. Mean pulse detection times were compared using Students t-test. The study was powered to determine whether US was not slower than MP by greater than 2 seconds. Results: A total of 93 participants completed the study. Time to detect pulse was 4.2 (SD=3.4) seconds by US compared with 4.7 (SD=6.5) seconds by MP (P=0.43). Seventeen (18%) participants took >5 seconds to identify the carotid pulse using US compared to 19 (20%) by MP (P=0.74). Eight (9%) candidates took >10 seconds to identify the pulse using US compared to 9 (10%) by MP (P=0.81). Prior to training, participants had a higher comfort level using MP than US pulse checks (67 vs 26 mm, P<0.001). Following the study, participants reported higher comfort levels using US than MP (88 vs 78 mm, P<0.001). Conclusion: Carotid pulse detection in live subjects was not slower using US as compared to MP in this study. A brief teaching session was sufficient to improve confidence of carotid pulse identification even in those with little to no previous US training. The preliminary results from this study provide the groundwork for larger studies to evaluate this pulse check method for patients in actual cardiac arrest.
Introduction: Ultrasound-guided intravenous (UGIV) insertion performed by nurses has been shown to be more effective than the blind approach for patients with difficult intravenous (IV) access in the emergency department (ED). While both the single-operator (SO) (where a single operator holds the IV and probe) and dual-operator (DO) (where a second operator holds the probe) techniques have been described, the DO is more resource-intensive, requiring a second operator to be present. The objective of this study is to compare the first-attempt cannulation success rates between a SO and DO technique in ED patients with predicted difficult access. Methods: We conducted a randomized controlled non-inferiority trial using a convenience sample of adult ED patients. Participating ED nurses received a one-hour UGIV training session including didactic and practical training on simulated arms. Patients were enrolled if they met any of three criteria for difficult access: (1) history of difficult access, (2) no visible or palpable veins, or (3) two failed blind attempts. Patients requiring active resuscitation, lack of suitable veins on US, or those unable to consent or comply with the procedure were excluded. Eligible patients were randomized to the SO or DO technique and a maximum of two UGIV attempts were allowed. The primary outcome was first-attempt success rate. Additional outcomes included overall success rate, number of attempts, time to successful cannulation, patient pain scores, operator ease of use scores, and complications 30 minutes after insertion. The chi-square test was used to compare success rates between groups and t-tests used for all other secondary outcomes. Results: 42 eligible patients have been approached for our study. 14 were excluded due to lack of visible veins on US or due to ongoing resuscitation. A total of 33 UGIV attempts were performed on 28 patients (17 in SO group, 16 in DO group). There was no statistically significant difference in first attempt success rates between the SO group of 76.5% (95% CI [50.1% to 93.2%]) and the DO group of 68.8% (95% CI [41.3% to 89%]) (p=0.62). There were also no statistically significant differences between the SO and DO groups in time to cannulation (140 vs 165 seconds, p=0.36), patient preference on a 10-point scale (7.0 vs 7.9, p=0.49), patient pain score (6.3 vs 6.6, p=0.87) or nursing ease of use (5.3 vs 6.5 p=0.23) respectively. There were no complications noted in either arm of the study. Conclusion: To date, the SO technique appears to be non-inferior to the DO technique for successful UGIV cannulation. Our results support the use of the SO technique, reducing the need for additional nursing resources when performing this procedure.
Sex between men is the most frequent mode of HIV transmission in industrialised countries. Monitoring risk behaviours among men who have sex with men (MSM) is crucial, especially to understand the drivers of the epidemic. A cross-sectional survey (PREVAGAY), based on time-location sampling, was conducted in 2015 among MSM attending gay venues in 5 metropolitan cities in France. We applied the generalised weight share method (GWSM) to estimate HIV seroprevalence for the first time in this population, taking into account the frequency of venue attendance (FVA). Our objectives were to describe the implementation of the sampling design and to demonstrate the importance of taking into account sampling weights, including FVA by comparing results obtained by GWSM and by other methods which use sample weights not including FVA or no weight. We found a global prevalence of 14.3% (95% CI (12.0–16.9)) using GWSM and an unweighted prevalence of 16.4% (95% CI (14.9–17.8)). Variance in HIV prevalence estimates in each city was lower when we did not take into account either the sampling weights or the FVA. We also highlighted an association of FVA and serological status in the most of investigated cities.
Recently, a new 2D carbon allotrope structure, named phagraphene (PG), was proposed. PG has a densely array of penta-hexa-hepta-graphene carbon rings. PG was shown to present low and anisotropic thermal conductivity and it is believed that this anisotropy should be also reflected in its mechanical properties. Although PG mechanical properties have been investigated, a detailed and comprehensive study is still lacking. In the present work we have carried out fully atomistic reactive molecular dynamics simulations using the ReaxFF force field, to investigate the mechanical properties and fracture patterns of PG membranes. The Young’s modulus values of the PG membranes were estimated from the stress-strain curves. Our results show that these curves present three distinct regimes: one regime where ripples dominate the structure and mechanical properties of the PG membranes; an elastic regime where the membranes exhibit fully planar configurations; and finally am inelastic regime where permanent deformations happened to the PG membrane up to the mechanical failure or fracture.
The study of the mechanical properties of nanostructured systems has gained importance in theoretical and experimental research in recent years. Carbon nanotubes (CNTs) are one of the strongest nanomaterials found in nature, with Young’s Modulus (EY) in the order 1.25 TPa. One interesting question is about the possibility of generating new nanostructures with 1D symmetry and with similar and/or superior CNT properties. In this work, we present a study on the dynamical, structural, mechanical properties, fracture patterns and EY values for one class of these structures, the so-called pentagraphene nanotubes (PGNTs). These tubes are formed rolling up pentagraphene membranes (which are quasi-bidimensional structures formed by densely compacted pentagons of carbon atoms in sp3 and sp2 hybridized states) in the same form that CNTs are formed from rolling up graphene membranes. We carried out fully atomistic molecular dynamics simulations using the ReaxFF force field. We have considered zigzag-like and armchair-like PGNTs of different diameters. Our results show that PGNTs present EY ∼ 800 GPa with distinct elastic behavior in relation to CNTs, mainly associated with mechanical failure, chirality dependent fracture patterns and extensive structural reconstructions.
To investigate the practice of hunting by local people in the southern Bahia region of Brazil and provide information to support the implementation of the National Action Plan for Conservation of the Central Atlantic Forest Mammals, we conducted 351 interviews with residents of three protected areas and a buffer zone. Thirty-seven percent of respondents stated that they had captured an animal opportunistically, 16% hunted actively and 47% did not hunt. The major motivation for hunting was consumption but people also hunted for medicinal purposes, recreation and retaliation. The most hunted and consumed species were the paca Cuniculus paca, the nine-banded armadillo Dasypus novemcinctus and the collared peccary Pecari tajacu; threatened species were rarely hunted. Opinions varied on whether wildlife was declining or increasing; declines were generally attributed to hunting. Our findings suggest there is illegal hunting for consumption in and around protected areas of the region. Management efforts should prioritize fairness in the expropriation process for people who must be relocated, and adopt an approach to wildlife management that involves residents living around the protected areas, and considers their needs.