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The constant search for the improvement of the performance of materials of industrial application, evaluated under aspects of weight reduction, greater resistance, greater resistance to wear and better thermal stability, among others, associated with the search for the development of ecologically viable products, that convert the context of environmental degradation in preservation and sustainability, reflects the need to conduct research that results in new materials. The objective of this work is to obtain composites of the AA6061 aluminum alloy reinforced with different contents of coke coal blast-furnace slag by powder metallurgy. The processing of these materials was done by sieving, mixing and compacting powders of reinforced aluminum alloy with 5, 10 and 15% of blast-furnace slag. The cold uniaxial compaction was realized at a pressure of 500MPa. The obtained materials were sintered at 580°C for 3h under inert atmosphere. Unreinforced aluminum alloy samples were also produced. The characterization of the materials was realized by density and hardness measurements and three-point bending tests. The analysis of its microstructure was realized by scanning electron microscopy. As results, the composites presented a homogeneous distribution of the reinforcing particles and also a progressive improvement of the hardness and the bending strength with the increase of the slag content, producing an increase of 79% in hardness and 128% in flexural strength, when compared to the material without reinforcement obtained by the same process. Such results give the coke coal blast-furnace slag a new possibility of exploitation in the metal-mechanical sector, besides contributing with the environmental issue.
Over recent decades, biomass gains in remaining old-growth Amazonia forests have declined due to environmental change. Amazonia’s huge size and complexity makes understanding these changes, drivers, and consequences very challenging. Here, using a network of permanent monitoring plots at the Amazon–Cerrado transition, we quantify recent biomass carbon changes and explore their environmental drivers. Our study area covers 30 plots of upland and riparian forests sampled at least twice between 1996 and 2016 and subject to various levels of fire and drought. Using these plots, we aimed to: (1) estimate the long-term biomass change rate; (2) determine the extent to which forest changes are influenced by forest type; and (3) assess the threat to forests from ongoing environmental change. Overall, there was no net change in biomass, but there was clear variation among different forest types. Burning occurred at least once in 8 of the 12 riparian forests, while only 1 of the 18 upland forests burned, resulting in losses of carbon in burned riparian forests. Net biomass gains prevailed among other riparian and upland forests throughout Amazonia. Our results reveal an unanticipated vulnerability of riparian forests to fire, likely aggravated by drought, and threatening ecosystem conservation at the Amazon southern margins.
There is a long history of exploitation of the South American river turtle Podocnemis expansa. Conservation efforts for this species started in the 1960s but best practices were not established, and population trends and the number of nesting females protected remained unknown. In 2014 we formed a working group to discuss conservation strategies and to compile population data across the species’ range. We analysed the spatial pattern of its abundance in relation to human and natural factors using multiple regression analyses. We found that > 85 conservation programmes are protecting 147,000 nesting females, primarily in Brazil. The top six sites harbour > 100,000 females and should be prioritized for conservation action. Abundance declines with latitude and we found no evidence of human pressure on current turtle abundance patterns. It is presently not possible to estimate the global population trend because the species is not monitored continuously across the Amazon basin. The number of females is increasing at some localities and decreasing at others. However, the current size of the protected population is well below the historical population size estimated from past levels of human consumption, which demonstrates the need for concerted global conservation action. The data and management recommendations compiled here provide the basis for a regional monitoring programme among South American countries.
The fraction of organic matter present affects the fragmentation behavior of sialoliths; thus, pretherapeutic information on the degree of mineralization is relevant for a correct selection of lithotripsy procedures. This work proposes a methodology for in vivo characterization of salivary calculi in the pretherapeutic context. Sialoliths were characterized in detail by X-ray computed microtomography (μCT) in combination with atomic emission spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Correlative analysis of the same specimens was performed by in vivo and ex vivo helical computed tomography (HCT) and ex vivo μCT. The mineral matter in the sialoliths consisted essentially of apatite (89 vol%) and whitlockite (11 vol%) with average density of 1.8 g/cm3. In hydrated conditions, the mineral mass prevailed with 53 ± 13 wt%, whereas the organic matter, with a density of 1.2 g/cm3, occupied 65 ± 10% of the sialoliths’ volume. A quantitative relation between sialoliths mineral density and X-ray attenuation is proposed for both HCT and μCT.
Determining the predictors of serum retinol at mid-pregnancy is relevant for planning interventions aimed at improving vitamin A status of pregnant women and their offspring. This prospective study assessed predictors of serum retinol at the beginning of the third trimester of pregnancy. We enrolled 442 pregnant women living in the urban area of Cruzeiro do Sul, Western Brazilian Amazon. Demographic, socio-economic, environmental and clinical characteristics as well as obstetric history, anthropometric, dietary and biochemical data, including serum retinol, were gathered between 16 and 20 gestational weeks. Serum retinol also measured at the beginning of the third trimester of pregnancy (approximately 28 gestational weeks) was the outcome of interest. Multiple linear regression models were used to evaluate associations with the outcome. Overall, the following variables explained serum retinol at the beginning of the third trimester of pregnancy in the adjusted model (R2 = 11·1 %): seasonality (winter season – November to April; β=0·134; 95 % CI 0·063, 0·206), weekly consumption of Amazonian fruits (β=0·087; 95 % CI 0·012, 0·162) and retinol concentrations between 16 and 20 gestational weeks (β=0·045; 95 % CI 0·016, 0·074) were positively associated, whereas having a smoker in the house was negatively associated (β=–0·087; 95 % CI: –0·166, –0·009). Consumption of pro-vitamin A-rich fruits by pregnant women should be encouraged. Passive smoking may play a role in decreasing vitamin A status as a proxy of smoking exposure during pregnancy.
Understanding cascading effects of species loss is a major challenge for ecologists. Traditionally, the robustness of ecological networks has been evaluated based on simulation studies where primary extinctions occur at random or as a function of species specialization, ignoring other important biological factors. Here, we estimate the robustness of a seed dispersal network from a grassland–forest mosaic in southern Brazil, simulating distinct scenarios of woody plant species extinction, including scenarios where species are eliminated based on their evolutionary and functional distinctiveness. Our results suggest that the network is more robust when species are eliminated based on their evolutionary uniqueness, followed by random extinctions, the extinction of the most specialist species, functional distinctiveness and, at last, when the most generalist species are sequentially eliminated. Our results provide important information for grassland–forest mosaic management, as they indicate that loss of generalist species and functional diversity makes the system more likely to collapse.
Symbiotic relationships are a common phenomenon among marine invertebrates, forming both obligatory and facultative dependencies with their host. Here, we investigate and compare the population structure of two crustacean species associated with both shallow and mesophotic ecosystems: an obligate symbiont barnacle (Ceratoconcha domingensis), of the coral Agaricia lamarcki and a meiobenthic, free-living harpacticoid copepod (Laophontella armata). Molecular analyses of the Cytochrome Oxidase Subunit I (COI) gene revealed no population structure between mesophotic and shallow barnacle populations within south-west Puerto Rico (ΦST = 0.0079, P = 0.33). The absence of population structure was expected due to the pelagic naupliar larvae of the barnacles and the connectivity patterns exhibited by the coral itself within the same region. Laophontella armata exhibited significant structure based on the mitochondrial COI gene between the mesophotic reef ecosystem of El Seco, Puerto Rico and mangrove sediments of Curaçao (ΦST = 0.2804, P = 0.0). The El Seco and Curaçao copepods shared three COI haplotypes despite the obligatory benthic development of harpacticoid copepods and the geographic distance between the two locations. Three other COI haplotypes from El Seco exhibited higher than expected (up to 7%) intra-species variability, potentially representing three new cryptic species of harpacticoid copepods or rare, deeply divergent lineages of L. armata. This result is evidence for the urgent need of a deeper investigation into the meiofauna diversity associated with mesophotic coral ecosystems (MCEs), arguably the most diverse metazoan component of MCEs.
Evidence suggests that skin picking disorder (SPD) could be a prevalent condition associated with comorbidity and psychosocial dysfunction. However, just a few studies have assessed the prevalence and correlates of SPD in samples from low- and middle-income countries. In addition, the impact of SPD on quality of life (QoL) dimension after multivariable adjustment to potential confounders remains unclear.
Data were obtained from a Brazilian anonymous Web-based research platform. Participants provided sociodemographic data and completed the modified Skin Picking–Stanford questionnaire, the Hypomania Checklist (HCL-32), the Patient Health Questionnaire-9 (PHQ-9), the Fagerström Test for Nicotine Dependence, Alcohol Use Disorder Identification Test (AUDIT), Symptom Checklist-90-Revised inventory (SCL-90R), early trauma inventory self report–short form, and the World Health Organization quality of life abbreviated scale (WHOQOL-Bref). Associations were adjusted to potential confounders through multivariable models.
For our survey, 7639 participants took part (71.3% females; age: 27.2±7.9 years). The prevalence of SPD was 3.4% (95% CI: 3.0–3.8%), with a female preponderance (P<0.001). In addition, SPD was associated with a positive screen for a major depressive episode, nicotine dependence, and alcohol dependence, as well as suicidal ideation. Physical and psychological QoL was significantly more impaired in participants with SPD compared to those without SPD, even after adjustment for comorbidity.
In this large sample, SPD was a prevalent condition associated with co-occurring depression, nicotine, and alcohol dependence. In addition, SPD was independently associated with impaired physical and psychological QoL. Public health efforts toward the early recognition and treatment of SPD are warranted.
This article analyzes recent Brazilian scholarship on workers and trade unions during the military dictatorship (1964–1985), emphasizing the relative absence of studies and the neglect of worker organization. By focusing on working-class agency and the dilemmas the labor movement faced due to the regime's economic policies and fierce repression, this essay offers a better understanding of the political scenario after 1964. The second part of the article examines the themes of the most recent studies about workers and the labor movement during the military regime, emphasizing existing blind spots and future challenges for scholarship.
Metal oxides like zinc oxide (ZnO) are promising materials for the active layer of thin-film transistors (TFTs) used in the drive circuit of next-generation large-area active matrix displays due to their high electronic mobility, high transmittance in the optical visible range and processability. Traditional deposition techniques employ RF sputtering or pulsed-laser deposition (PLD), which are relatively sophisticated techniques. The deposition of very thin (less than 50 nm thick) layers of ZnO using soluble organic precursors have been extensively investigated recently as an alternative to traditional deposition methods. Solution-based deposition processes include simple and affordable techniques like dip-coating, spin-coating, spray-pyrolysis and ink-jet printing. Spray-pyrolysis is particularly interesting due to the high film uniformity, low cost and high device performance. We carried out several experiments analyzing the performance of ZnO based devices using zinc acetate as organic precursor to confirm that spray pyrolysis deposition is a suitable technique for production of high-performance and reproducible TFTs. Moreover, we observed that device performance can significantly vary with little modifications on the deposition parameters, even for the same active layer composition and pyrolysis temperature. Electrical parameters, as the electrical mobility and the on/off ratio, varied several orders of magnitude, whereas the threshold voltage varied up to 20 V for the tested devices. Deposition parameters as the nozzle height during the deposition, nozzle air pressure and deposition time were varied until we obtained devices with optimum electrical performance. Optimized devices presented mobilities in the order of 1 cm2.V-1.s-1, on/off ratio of about 106 and relatively low operation voltages. A statistical analysis of a great number of devices manufactured using the same deposition parameters was also carried out to assure the reproducibility of the deposition technique.
Parasites of the genus Trypanosoma are unicellular flagellated microorganisms of the Trypanosomatidae. This study describes an isolate of the genus Trypanosoma naturally infecting Rhipicephalus microplus ticks, characterized through molecular, morphological and biological analysis. Trypanosome cultures, designated strain P1RJ, were obtained by isolation from R. microplus haemolymph in cultures of the tick cell line IDE8. After isolation, strain P1RJ grew well axenically in L15B medium at temperatures of 30, 32 and 34 °C. The new trypanosome remained stable in axenic culture over 14 passages in L15B at 30 °C and was successfully cryopreserved and resuscitated. Morphometric analysis was performed on randomly selected developmental forms. 18S rRNA and 24Sα rDNA sequence analyses confirmed that strain P1RJ is a new species of the genus Trypanosoma. The nucleotide sequences described were submitted to Genbank. Pathogenicity, involvement in vertebrate hosts, epidemiology, developmental cycle and transmission mechanisms of strain P1RJ are still unknown. Therefore, more studies will be necessary to determine life cycle aspects of this trypanosome, for which we propose the name Trypanosoma rhipicephalis sp. nov.
The canine golden retriever muscular dystrophy (GRMD) model is the best animal model for studying Duchenne muscular dystrophy in humans. Considering the importance of glucose metabolism in the muscles, the existence of metabolic and endocrine alterations in a wide range of muscular dystrophies, and the pre-existing relationship between blood insulin concentration and muscular atrophy, the present study aimed to evaluate the postprandial glucose and insulin response in GRMD dogs. A total of eighteen golden retriever dogs were randomly distributed into three experimental groups: healthy/control (G1), female GRMD carriers (G2), and male dogs affected by GRMD (G3). Higher plasma resting glucose levels (P = 0·0047) were seen in G2 and G3 compared with G1, as was the case for minimum (P = <0·0001), mean (P = 0·0002) and maximum (P = 0·0359) glucose values for G3 compared with G1. Fructosamine concentrations were in accordance with reference values found in the literature for dogs. Insulin levels were lower in G3 compared with G1 (P = 0·0065); however, there was no evidence of insulin resistance according to the homeostasis model assessment index values obtained. As for the evaluation of postprandial responses, fluctuations of glucose (P = 0·0007) and insulin (P = 0·0149) were observed in G1 and G2, while in G3 the values remained constant. The results allowed us to identify metabolic changes related to carbohydrate metabolism in GRMD dogs, highlighting the importance of adequate food management for these animals.
To report an evaluation of health professionals’ participation in a distance-learning physical activity training course developed in a low socio-economic region of São Paulo city, Brazil.
In countries with public universal health systems, physical activity promotion in primary health care settings can reap results, particularly given that such interventions have the potential to reach a large percentage of the population. However, few studies proposed physical activity training for health professionals in low- and middle-income countries. Brazil is a continental country and has the Unified Health System which incorporates family health teams in over 85% of Brazilian cities.
The physical activity training was part of the fifth module of an educational intervention throughout a distance-learning course focusing on health professionals at M’Boi Mirim district in São Paulo city. The training totaled 3 h and had five themes of physical activity: (1) concepts, definitions benefits; (2) evaluation; (3) recommendation; (4) interventions; (5) physical activity counseling. The opinion of health professionals was evaluated after training by two open questions.
Out of 106 professionals who took part of the course, only 22.6% (n=24) had accessed the fifth module. These professionals were predominantly female (79.2%), nurses (66.7%) and aged 30 years or older. Responses highlighted the course approach focused on physical activity for improving patient’s quality of life and well-being, disease prevention and health improvements. Regarding the themes for improvement, the health professionals identified that there was a need to experience physical activity classes first-hand, and the need to link physical activity counseling to the local venues that provide structured physical activity programs. We recommend that further training courses can be conducted based on this model for health professionals to promote physical activity to the community in Brazil.
With the release of dicamba-resistant crops, it is necessary to understand how technical and environmental conditions affect the application of dicamba. This study sought to evaluate drift from dicamba applications through flat-fan nozzles, under several wind speeds in a wind tunnel. Dicamba applications were performed through two standard (XR and TT) and two air induction (AIXR and TTI) 110015 nozzles at 0.9, 2.2, 3.6 and 4.9 ms−1 wind speeds. The applications were made at 276 kPa pressure and the dicamba rate was 561 g ae ha-1. The droplet spectrum was measured using a laser diffraction system. Artificial targets were used as drift collectors, positioned in a wind tunnel from 2 to 12 m downwind from the nozzles. Drift potential was determined using a fluorescent tracer added to solutions, quantified by fluorimetry. The air induction TTI nozzle produced the lowest percentage of dicamba drift at 2.2, 3.6 and 4.9 ms−1 wind speeds at all distances. Dicamba spray drift from XR, TT and AIXR nozzles increased exponentially as wind speed increased, whereas from TTI nozzle drift increased linearly as wind speed increased. Drift did not increase linearly as the volume percentage of droplets smaller than 100 µm and wind speed increased.
The widespread occurrence of Palmer amaranth resistant to acetolactate synthase inhibitors and/or glyphosate led to the increased use of protoporphyrinogen oxidase (PPO)-inhibiting herbicides. This research aimed to: (1) evaluate the efficacy of foliar-applied fomesafen to Palmer amaranth, (2) evaluate cross-resistance to foliar PPO inhibitors and efficacy of foliar herbicides with different mechanisms of action, (3) survey the occurrence of the PPO Gly-210 deletion mutation among PPO inhibitor–resistant Palmer amaranth, (4) identify other PPO target-site mutations in resistant individuals, and (5) determine the resistance level in resistant accessions with or without the PPO Gly-210 deletion. Seedlings were sprayed with fomesafen (263 gaiha−1), dicamba (280 gaiha−1), glyphosate (870 gaiha−1), glufosinate (549 g ai ha−1), and trifloxysulfuron (7.84 gaiha−1). Selected fomesafen-resistant accessions were sprayed with other foliar-applied PPO herbicides. Mortality and injury were evaluated 21 d after treatment (DAT). The PPX2L gene of resistant and susceptible plants from a selected accession was sequenced. The majority (70%) of samples from putative PPO-resistant populations in 2015 were confirmed resistant to foliar-applied fomesafen. The efficacy of other foliar PPO herbicides on fomesafen-resistant accessions was saflufenacil>acifluorfen=flumioxazin>carfentrazone=lactofen>pyraflufen-ethyl>fomesafen>fluthiacet-methyl. With small seedlings, cross-resistance occurred with all foliar-applied PPO herbicides except saflufenacil (i.e., 25% with acifluorfen, 42% with flumioxazin). Thirty-two percent of PPO-resistant accessions were multiple resistant to glyphosate and trifloxysulfuron. Resistance to PPO herbicides in Palmer amaranth occurred in at least 13 counties in Arkansas. Of 316 fomesafen survivors tested, 55% carried the PPO Gly-210 deletion reported previously in common waterhemp. The PPO gene (PPX2L) in one accession (15CRI-B), which did not encode the Gly-210 deletion, encoded an Arg-128-Gly substitution. The 50% growth reduction values for fomesafen in accessions with Gly-210 deletion were 8- to 15-fold higher than that of a susceptible population, and 3- to 10-fold higher in accessions without the Gly-210 deletion.
The IceCube Neutrino Observatory was constructed at the South Pole during the 2004/05 to 2010/11 austral summer seasons. IceCube transforms 1 km3 of Antarctic ice into an astrophysical particle detector composed of 86 cables (strings) of optical sensors buried deep beneath the surface. Each string required drilling a borehole ∼60 cm in diameter to a depth of 2500 m. The 5 MW Enhanced Hot Water Drill was designed and built specifically for this task, capable of producing the required boreholes at a rate of one hole per 48 hours. Hot-water drilling on this scale presented unique challenges and was rich in lessons learned, yielding a collection of notable developments and takeaways (e.g. fuel-saving measures, thermal modeling, firn drilling and closed-loop computer control). Descriptions of system functionality and of lessons learned from IceCube drilling are presented.
IceCube, a cubic-kilometer neutrino detector, was built at the South Pole using a hot-water drill system. Deep holes were drilled into the Antarctic ice sheet and filled with highly sensitive optical instrumentation. For the hot-water drilling, a computer model was developed to predict the hole sizes and hole lifetimes during construction. The goal was to predict ultimate size and freezeback rates based on water flow rate and temperature, drill speed, ice temperature and ream parameters (for a secondary operation where hot water continues to flow as the drill is withdrawn). This model proved to be very successful. It increased confidence that the holes would remain open long enough after drilling to allow the deployment of the necessary instrumentation. It also allowed for a decrease, over the course of the project, in the amount of overdrilling that was used as a margin against a too-rapid freeze-in. This resulted in significant fuel savings.
With the recent introductions of glyphosate- and dicamba-tolerant crops, such as soybean and cotton, there will be an increase in POST-applied tank-mixtures of these two herbicides. However, few studies have been conducted to evaluate drift from dicamba applications. This study aimed to evaluate the effects of dicamba with and without glyphosate sprayed through standard and air induction flat-fan nozzles on droplet spectrum and drift potential in a low-speed wind tunnel. Two standard (XR and TT) and two air induction (AIXR and TTI) 110015 nozzles were used. The applications were made at 276 kPa pressure in a 2.2 ms−1 wind speed. Herbicide treatments evaluated included dicamba alone at 560 gaeha−1 and dicamba+glyphosate at 560+1,260 gaeha−1. The droplet spectrum was measured using a laser diffraction system. Artificial targets were used as drift collectors, positioned in a wind tunnel from 2 to 12 m downwind from the nozzle. Drift potential was determined using a fluorescent tracer added to solutions, quantified by fluorimetry. Dicamba droplet spectrum and drift depended on the association between herbicide solution and nozzle type. Dicamba alone produced coarser droplets than dicamba+glyphosate when sprayed through air induction nozzles. Drift decreased exponentially as downwind distance increased and it was reduced using air induction nozzles for both herbicide solutions.
Blastocystis sp. is a protozoan commonly found in human and animal stool samples. Several pathogenic and zoonotic aspects of this organism are still unknown. The aim of the present study was to investigate Blastocystis subtypes (STs) in samples from patients of the Hospital das Clínicas of the Faculdade de Medicina at the Universidade de São Paulo (HC-FMUSP), Brazil. Blastocystis sp.-positive stool samples diagnosed at the Section of Parasitology of the Central Laboratory (HC-FMUSP) were used for DNA isolation. Polymerase chain reaction (PCR) was performed using specific primers targeting the small-subunit rRNA gene. Direct DNA sequencing of the PCR products was performed and the DNA sequences were then aligned and compared with other sequences obtained from the GenBank database. Phylogenetic analysis was used to identify STs and determine the phylogenetic relationships between the sequences. Four STs were identified: ST1 (22·5%), ST2 (12·5%), ST3 (60%) and ST6 (5%). In conclusion, ST3 was the most prevalent ST among the human isolates followed by ST1. The present study is one of the few providing STs data from the human population in South America. Determining ST prevalence in human samples may contribute to the monitoring of Blastocystis sp. infection transmission in endemic regions.
The control of dengue constitutes a great challenge for public health; however, the methods normally used have shown themselves to be insufficient to keep the indices of infestation of Aedes aegypti under control. Recently, beyond the large number of cases and deaths associated with dengue, new risks have arisen such as those represented by chikungunya fever and Zika. In the light of the great significance of these problems within the public health context, two areas in a municipality in the interior of the State of São Paulo, Brazil were selected in 2014. One of them, Bairro Cidade Nova, was submitted to the conventional method of nebulization with portable equipment, and the other, Bairro Jardim Europa, received the application of the insecticide by means of heavy-equipment coupled to the vehicle. During the project, 1355 mosquito eggs were collected, 1105 of them in Bairro Cidade Nova and 205 in Bairro Jardim Europa. After the applications with heavy-equipment in the months of March and April, the number of cases of the disease reported in the month of April for Bairro Jardim Europa was less than half that of Bairro Cidade Nova, which had received the conventional treatment. The nebulization with the heavy-equipment may constitute a viable and effective strategy for achieving better results in the control of Ae. aegypti.