Southern Brazil Research Articles

Fertilizer and Lime Impacts on Edaphic Mesofauna in a Southern Brazil Loblolly Pine System

Fertilizer and Lime Impacts on Edaphic Mesofauna in a Southern Brazil Loblolly Pine System

Contribution to the taxonomy of Oxytrigona Cockerell, 1917 (Apidae, Meliponini)

The stingless bees of the genus Oxytrigona Cockerell are popularly known as “fire bees”, due to their unique habit of spitting a caustic secretion when disturbed. Currently, this neotropical genus includes 11 valid species distributed from southern Brazil, throughout most of South and Central America, reaching southern Mexico. They are especially diverse in the Amazon, where five species are recorded. Although Oxytrigona exhibits a very distinctive morphology in relation to other stingless bees, species are often difficult to identify, having blurred limits due to intraspecific variation. In the present contribution the taxonomy of Oxytrigona is revisited, based on novel findings since the last taxonomic accounts were made. Oxytrigona tataira (Smith, 1863) is reinterpreted on the basis of new evidence regarding the provenance of its type material. The whereabouts of the type material of Oxytrigona cagafogo (Müller, 1874) sp. ressur. are discussed, and the species is resurrected from synonymy, representing a common bee occurring in the Atlantic rainforest of Brazil. Oxytrigona huaoranii Gonzalez & Roubik, 2008 is considered a junior synonym of Oxytrigona mellicolor (Packard, 1869) syn. nov., and the identity of the species is clarified. The whereabouts of the type material of Oxytrigona flaveola (Friese, 1900) are discussed. Three new species are described: Oxytrigona banana sp. nov. from Brazil and Paraguay; Oxytrigona pallida sp. nov. from northern South America and Central America; and Oxytrigona sauronica sp. nov. from Colombia. Distribution maps and a revised key are provided. Although the taxonomy of Oxytrigona species has been improved, questions remain about some species complexes. Implementation of tools from phylogeography is encouraged in order to improve our understanding of the species boundaries.

Contamination by potentially toxic metals from urban rivers located in an area covered by the Guarani Aquifer in Southern Brazil

The present study aimed to evaluate the concentration of heavy metals considered globally alarming, such as cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb) and zinc (Zn), in the surface water and in the sediment of urban rivers located in an area covered by the Guarani Aquifer, in Lages, southern Brazil. The water and sediment samples were collected in September and October 2016 in three urban rivers. The quantification of the metals was performed through an atomic absorption spectrometer. The levels of Cd, Cr, Cu, Pb and Zn in the control points (P1 and P7) presented a concentration below the level I proposed by Brazilian legislation 344/2004 of the National Environment Council (CONAMA), while the other points presented concentrations higher and above level I, evidencing an increase of metals in the rivers from upstream to downstream of the urban area of ​​Lages. Cr concentrations above level II proposed by Brazilian legislation at the mouth of the Carahá River were also found, and this value may have adverse effects on aquatic biota. The results show that urban rivers in the area covered by the Guarani Aquifer in Lages have been contaminated by toxic elements associated with anthropogenic activities.

Mazaceae in the state of Rio Grande do Sul (Brazil): new records of Mazus pumilus (Burm.f) Steenis

Mazaceae in the state of Rio Grande do Sul (Brazil): new records of Mazus pumilus (Burm.f) Steenis. This work contributes to the knowledge about the naturalized species existing in Brazil, with a historical review of the records of Mazus pumilus in the national territory and with the report of the news records of the Mazaceae family for the Pampa biome and the state of Rio Grande do Sul, Southern Brazil, with the occurrence of M. pumilus in the municipalities of Santa Maria and Pelotas. The material was photographed in situ, collected, and registered in herbaria SMDB and ECT.

Constructal Design Applied to an Overtopping Wave Energy Converter Locate on Paraná Coast in Brazil

This research aims a numerical and geometrical investigation about an Overtopping Device Wave Energy Converter (OTD-WEC). Constructal Design method was employed to perform a geometric evaluation of this OTD-WEC submitted to ocean waves with similar characteristics of the coastal region of Paraná State – Pontal do Paraná city in southern Brazil, located 41 km from the coast and 30 m water deep. It was analyzed two different significant wave heights, HS1 = 1.25 m and HS2 = 1.50 m. In each set, it were simulated 10 cases with different ramp angles, totaling 20 numerical simulations. The main goal was to evaluate the influence of the ramp angle on the water mass flow rate entering the reservoir. Therefore, through the Construtal Design, the degree of freedom (DOF) H1/L1 (ratio between the height and length of the ramp) was varied, considering a constant area of the ramp. For the numerical analysis, a two-dimensional computational model was employed using the commercial software Ansys Fluent, which is based on the Finite Volume Method (FVM). The multiphase Volume of Fluid (VOF) model was applied to tackle with the water-air interaction. The results showed that the best geometric configurations happened for those cases with smaller ramp angles. In addition, a reconfiguration of the ramp angles, keeping the area fixed, allowed a significant improvement in the OTD-WEC available power.

Constructal Design Applied to an Overtopping Wave Energy Converter Locate on Paraná Coast in Brazil

This research aims a numerical and geometrical investigation about an Overtopping Device Wave Energy Converter (OTD-WEC). Constructal Design method was employed to perform a geometric evaluation of this OTD-WEC submitted to ocean waves with similar characteristics of the coastal region of Paraná State – Pontal do Paraná city in southern Brazil, located 41 km from the coast and 30 m water deep. It was analyzed two different significant wave heights, HS1 = 1.25 m and HS2 = 1.50 m. In each set, it were simulated 10 cases with different ramp angles, totaling 20 numerical simulations. The main goal was to evaluate the influence of the ramp angle on the water mass flow rate entering the reservoir. Therefore, through the Construtal Design, the degree of freedom (DOF) H1/L1 (ratio between the height and length of the ramp) was varied, considering a constant area of the ramp. For the numerical analysis, a two-dimensional computational model was employed using the commercial software Ansys Fluent, which is based on the Finite Volume Method (FVM). The multiphase Volume of Fluid (VOF) model was applied to tackle with the water-air interaction. The results showed that the best geometric configurations happened for those cases with smaller ramp angles. In addition, a reconfiguration of the ramp angles, keeping the area fixed, allowed a significant improvement in the OTD-WEC available power.

Fuscoporia nebularis, (Hymenochaetaceae) a new endemic and threatened species from the cloud forests of southern Brazil

A new and threatened species of Fuscoporia from the cloud forests of southern Brazil is described. This species, associated with hardwood species of Myrtaceae, differs from other Fuscoporia species by having broadly ellipsoid basidiospores (2.9–3.8 × 2.3–3.1 µm) and hymenial setae that occasionally have a bifurcate and curved apex. Additionally, molecular analysis based on ITS and nrLSU sequences supports the new species. The conservation status of this new species of Fuscoporia is assessed as ‘Endangered’ based on IUCN criteria. We present the new species with illustrated morphological description, phylogenetic analyses and comparison with morphologically similar or related species. A key to the neotropical species of Fuscoporia is provided.

Association between obesity and common mental disorders in women: a population-based study in Southern Brazil.

The study aimed to investigate the relationship between obesity and common mental disorders (CMD) among women. This is a cross-sectional population-based study with a representative sample of 981 adult women (20-60years of age) living in the urban area of the municipality of São Leopoldo, RS, Brazil, in 2015. The presence of CMD was assessed using the Self-Reporting Questionnaire (SRQ-20 ≥ 8). Obesity was defined by body mass index (BMI ≥ 30.0kg/m2). Prevalence ratios (PRs) for the association between obesity and CMD were measured by Poisson regression with robust variance, including their respective 95% confidence intervals (CIs). The mean age of the sample was 40.3years (standard deviation = 11.4years). The prevalence of CMD was 33.7% (95% CI 30.8-36.7), while obesity was 31.2% (95% CI 28.3-34.1). The occurrence of CMD was higher in women with low levels of education and belonging to lower economic class, as well as smokers and those who were insufficiently active. Obesity was more prevalent in older women (50-60years old) with less schooling, who did not consume alcohol, and those who were insufficiently active. After adjusting for potential confounding factors, women with obesity were 22% more likely to have CMD when compared to those without obesity (PR = 1.22; 95% CI 1.02-1.45; p = 0.030). This study demonstrated a significant association between obesity and the presence of CMD among women. Additionally, the prevalence of obesity and CMD were high in this population group.

A new “silesaurid” from the oldest dinosauromorph-bearing beds of South America provides insights into the early evolution of bird-line archosaurs

Investigations regarding the early evolutionary history of bird-line archosaurs have undergone significant advancements in recent years. However, controversies remain, especially regarding the phylogenetic position of “silesaurids”. Whereas some hypotheses place these archosaurs as the sister-group to dinosaurs, others suggest that “silesaurids” are early ornithischian dinosaurs. Despite the phylogenetic disputes, “silesaurids” are a crucial group for comprehending the origins and early evolution of dinosaurs. In the present study, a new “silesaurid” from the Middle-Upper Triassic of Southern Brazil is described. Gondwanax paraisensis gen. et sp. nov. comes from the Dinodontosaurus Assemblage Zone of the Santa Maria Formation (Ladinian-Carnian boundary), representing one of the oldest “silesaurids” worldwide. Furthermore, Gondwanax paraisensis gen. et sp. nov is the oldest “silesaurid” with three sacral vertebrae, a feature usually observed in more derived forms. In addition, distinct from any other Triassic Pan-Aves, the new taxon bears an incipient fourth trochanter of the femur. This unique combination of features indicates a high diversity of locomotor strategies among early pan-avians. The co-occurrence of Gondwanax paraisensis gen. et sp. nov. and Gamatavus antiquus in the same Assemblage Zone represents the oldest evidence of sympatry among “silesaurids” in South America. Indeed, the unique combination of sacral and hindlimb features may suggest distinct behaviors for these species, potentially leading to niche differentiation within the same ecosystems.

Comparative study of non-suppurative meningoencephalitis in cattle in Southern Brazil.

Viral neurologic diseases are common in cattle, although most non-suppurative meningoencephalitis (NSM) remains etiologically unknown. We compared the epidemiological, clinical, and pathological data among 79 cases of rabies, 12 cases of NSM of unknown etiology (NSM-UE), and 8 cases of herpetic meningoencephalitis previously diagnosed in cattle in Southern Brazil. Neurological clinical signs were similar among rabies and NSM-UE and different in cattle with herpetic meningoencephalitis. Only two herpetic meningoencephalitis cases had gross lesions in the central nervous system, characterized by malacia and hemorrhage. Histologically, all three groups had mild to severe multifocal infiltrates of lymphocytes, plasma cells, and macrophages/microglial cells in the Virchow-Robin space, neuropil, and leptomeninges, and gliosis. Other findings included malacia and eosinophilic intracytoplasmic inclusion in rabies, and malacia and intranuclear amphophilic inclusion in herpetic meningoencephalitis. By immunohistochemistry, the predominant inflammatory cells in all cases were T lymphocytes, followed by macrophages/microglial cells, B lymphocytes, and astrocytes. The T lymphocyte count showed statistically significant differences between the diseases. Our results revealed few differences between the groups. Although the etiological agent involved has not been identified in cases of NSM-UE, the characteristics observed in this study showed similarity with viral diseases.

A bioeconomic model for a multispecies small-scale fishery system

A fishery encompasses various interconnected systems, including ecological, socioeconomic, and governing systems. Managing fisheries requires the simultaneous consideration of all these systems, making it a challenging endeavor. To address these challenges, fisheries bioeconomic models have emerged as a crucial tool. They are particularly valuable in the context of small-scale fisheries, which are often complex, overlooked and poorly understood. Thus, this paper presents a dynamic multispecies and multigear bioeconomic model that can illuminate the ecological, economic, and social dimensions of small-scale fisheries under different management scenarios. The model was applied to a small-scale fisheries system in Southern Brazil that has as a notable feature a cooperative fishing behavior between dolphins and fishers. Three scenarios were explored: the base scenario (status quo), the optimal management scenario, and the constrained optimal management scenario. The model outputs demonstrated a clear tradeoff between labour effort, species conservation, and economic rent. Shifting from the base to an optimal management scenario would result in a labour employment reduction within the system but concurrently yield higher stock levels, economic rent, and wages. These results illustrate how our model can explore critical management scenarios across the multiple dimensions of fisheries systems. In essence, this research offers a novel contribution in the form of a bioeconomic model tailored for small-scale fisheries involving multiple species.

Assessing leptospirosis and toxoplasmosis seropositivity in wild boars (Sus scrofa): Implications for public and animal health in Southern Brazil

Leptospirosis and toxoplasmosis are re-emerging zoonosis caused by infection with pathogenic spirochaetes of Leptospira and the protozoa Toxoplasma gondii, respectively. Wild boars (Sus scrofa), an exotic invasive species in Brazil, could play a role in the diseases’ epidemiological cycles, but this issue is still unexplored. This study aimed to evaluate the Leptospira spp. and T. gondii seropositivity in wild boars in Rio Grande do Sul state, south Brazil. Of evaluated animals, 16% (13/80) and 85% (52/61) had antibodies to T. gondii and Leptospira spp., respectively. Sex, weight, age, hunt location and season of hunt were evaluated by their association with seropositivity for both pathogens, but none of them had statistical significance. This study revealed that wild boars should be considered as a potential source of Leptospira spp. and T. gondii dissemination for humans and animal species in shared environments in Rio Grande do Sul state.

Prevalence of muscle atrophy in pediatric patients during ICU hospitalization.

To evaluate the muscle thickness and prevalence of muscle atrophy of the biceps brachii/brachialis (BB) and quadriceps femoris (QF) in critically ill children using ultrasound (US). The prospective longitudinal study was conducted in the pediatric intensive care unit (PICU) of a tertiary hospital in southern Brazil with children and adolescents of both sexes, aged 1month to 12years, on invasive mechanical ventilation for 24h. US measurements were taken up to 24h after admission, 72h after, and weekly until discharge from the PICU. One hundred one patients were selected, of whom 97 underwent two evaluations, 68 three evaluations, and 26 four ultrasound evaluations. The median age was 6months, with 63 (62.4%) < 1year old. The most prevalent clinical diagnosis was respiratory diseases (70.3%). There was a reduction in BB thickness from 1 to 2weeks (- 0.10cm, p = 0.009) and in QF from 24h to 2weeks (- 0.20cm, p = 0.013) and 72h to 2weeks (- 0.18cm, p = 0.045). The prevalence of muscle atrophy (decrease > 10% in thickness) was 41.2% in at least one muscle group between 24 and 72h, 39.7% between 24h and 1week, and 59.3% between 24h and 2weeks. The US allows the evaluation of BB and QF muscle thickness in critically ill children, and monitoring muscles during PICU hospitalization is important. The prevalence of muscle atrophy was 30.8% in the biceps brachii and 46.2% in the quadriceps femoris at the end of 2weeks of PICU hospitalization, regardless of age and diagnosis. What is Known: • Ultrasound has emerged as a promising method, being a clinically valuable tool for bedside muscle monitoring in critical patients. • Using the ultrasound to measure the muscle thickness in adults has demonstrated good sensitivity for detecting muscle atrophy. However, this method has only been previously validated in few studies with small sample of pediatric patients. What is New: • Using the ultrasound, we observed that critically ill children experienced a loss of muscle thickness and muscle atrophy, especially during the second week of intubation. • The significant prevalence of muscle atrophy at the end of PICU hospitalization highlights the importance of ultrasound in identifying muscle loss.

Desertic siliciclastic stromatolites in the Upper Jurassic Guará Formation from southwestern Gondwana: Trapping and binding in a non-marine setting

Siliciclastic stromatolites are rare in the geologic record, and their occurrence recorded in the literature is restricted to marine and coastal environments. The Upper Jurassic Guará Formation, from the Paraná Basin in southern Brazil, hosts unique non-marine siliciclastic stromatolites, providing a rare opportunity to study trapping and binding mechanisms by microbial mats in a continental setting. These microbialites occur interbedded with eolian and fluvial facies. The structural layering of the stromatolite domes is formed by the intercalation of sandy layers, resulting from trapping and binding of siliciclastic grains by microbial mats and in situ precipitation of amorphous to cryptocrystalline silica, which directly replaced the microbial colonies. The silica layers contain partially preserved spherical to ovoid bodies interpreted as colonies of coccoid microorganisms. These siliciclastic stromatolites were formed due to a specific balance of environmental factors, namely water chemistry and sediment supply, which enhanced the processes of trapping and binding and in situ precipitation. They record the presence of microbial life in a non-marine, silica-rich, fluvial-eolian environment in which there were no previous published occurrences of agglutinated stromatolites. These specimens record macroscopically identifiable evidence of microbial life in a continental environment that must be accounted for in the search for ancient life on Earth and Mars.

Soil hydraulic properties, mineralogical alteration and pore formation in Regosols from southern Brazil

ABSTRACT Regosols (Neossolos) are soils with use limitations mainly related to effective depth, abundant presence of rock and saprolite fragments, and frequently high slope gradients; besides that, they represent a new agricultural frontier for grain production in southern Brazil. This study evaluated soil saturated hydraulic conductivity (K sat ) and water retention and availability in Regosols and saprolites derived from volcanic rocks in southern Brazil and the relationship of these variables with porosity in saprolithic horizons characterized by mineralogical weathering. The study was carried out on eight profiles derived from basic and acidic volcanic rocks of the Serra Geral Formation. We evaluated soil morphology, granulometry, porosity, bulk density (BD), K sat , water retention, electronic/ optical microscopy and chemical composition of parent materials, and soil mineralogy. Soil K sat ranged from 0.0 to 6.40 cm h -1 in the evaluated horizons, without significant difference between the A and Cr horizons. Seven soil profiles showed BD equal to or less than 1.28 Mg m -3 for the Cr samples. Total porosity in the Cr horizons was above 0.5 m 3 m -3 and not significantly different from A horizons. In five of the eight soil profiles, one or more Cr horizons presented greater available water than A horizons. Electronic and optical microscopy evidenced abundant cracks and mineralogical weathering in the rock samples. X-rays diffraction data also indicated advanced degree of weathering of Cr horizons, evidencing abundant formation of pores in the saprolite. and justifying the high-water retention in Regosols profiles in southern Brazil.

Splenic rupture in dairy cattle: Report of 24 cases.

Splenic rupture in cattle is scarcely described in the literature. The aim of this work was to report the occurrence of splenic rupture in cattle in southern Brazil as well as to describe the causes of the condition. Between 2013 and 2022, 24 of the 1769 bovine necropsies performed in southern Brazil were due to splenic rupture, accounting for 1.36% of the diagnoses. Animals died due to hemoperitoneum caused by a rupture in the splenic capsule, typically associated with marked splenomegaly and a large hematoma between the capsule and the parenchyma. Clinical signs were described in a subset of cases (11 of 24 cases, 46%) and included apathy, abdominal pain, mucosal pallor, tachycardia, and respiratory distress. However, the majority (13 of 24 cases, 54%) presented as sudden death. The underlying cause of splenic rupture was established as follows: 16 cases (67%) secondary to babesiosis, 4 cases (17%) due to lymphoma, 1 case (4%) due to a thrombus, 1 case (4%) due to external trauma, 1 case due to a ruptured nodular lymphoid hyperplasia (4%), and 1 case of undetermined cause (4%). Hypovolemic shock caused by splenic rupture is an important cause of death of dairy cattle, and babesiosis and bovine leukemia virus-associated lymphoma are among the most common etiologic diagnoses (84% of cases). The description of the causes of this condition is important to clarify the pathogenesis and occurrence of splenic rupture in dairy cattle.

Use and recovery of P reserves in Southern Brazil Oxisols under no-till with low and high P availability

ABSTRACT The accessibility of soil P reserves by plants on highly weathered Brazilian soils remains unclear. In this study, we assessed the contribution of soil P fractions to P uptake by soybean plants in two no-till Oxisols (Latossolos), with low and high initial content of available P. The recommended P rates (viz., 153 and 50 kg ha -1 yr -1 in the low-P and high-P soil, respectively) were applied in the form of triple superphosphate (TSP) or Bayovar rock phosphate (BRP) plus a treatment without fertilizer. Yields of winter cereals and soybean on the studied soils were examined over a period of three years. Soil samples were collected in the 0.00-0.10 m soil layer and subjected to sequential chemical fractionation of P. In the last crop season, the P content of soybean shoot biomass was determined. Soil P fractions and P content of soybean shoots were subjected to path analysis. The addition BRP in the low-P soil resulted in a winter cereal yield of 2.0 Mg ha -1 lower than TSP. In the scenario of high P, it is possible to maintain high crop yields even without phosphate fertilization for three consecutive years. Path analyses demonstrated the addition of P using either TSP or BRP boosted the contribution of the more labile inorganic P fractions. The addition of BRP should be avoided in P-deficient soils. The addition TSP or BRP reduces the pressure of plants to use soil P reserves. Therefore, the soil P legacy should be considered in fertilization recommendations for high-P soils in NT.

Intergenerational income mobility and returns to education in Southern Brazil

This study analyzes intergenerational income mobility in Southern Brazil. Previous research has demonstrated that Brazil continues to be one of the least mobile countries in the world; however, the country has experienced strong socioeconomic advances in recent decades that may have affected mobility. The use of data from the 1982 birth cohort in the city of Pelotas, in the extreme south of Brazil, makes this one of the first studies to estimate mobility using direct observations of parental and filial income in Brazil. Using various estimation techniques, the results reveal relatively high income mobility compared with past Brazilian standards. Mobility is higher for nonwhites, extremely similar across genders, and higher among the poor. The findings indicate that increased government investment in education and reduced returns to education in recent decades are possible channels.

Prevalence and factors associated with probable sarcopenia in southern Brazil: a population-based study.

There are few studies on probable sarcopenia in rural areas. This study aims to assess prevalence of probable sarcopenia and its associated factors in older adults living in the rural area of a municipality in southern Brazil. This cross-sectional study assessed data from the second wave of the EpiRural Cohort Study. Structured questionnaires, handgrip strength, gait speed, and anthropometric measurements were collected from 651 older adults. The criteria from the European Working Group on Sarcopenia in Older People 2 were used in this study. Chi-square test and logistic regression with robust variance were performed. Prevalence of probable sarcopenia was 19.2% (95% confidence interval (CI): 16.3-25.2%). Male sex (prevalence ratio (PR) 1.61; 95%CI 1.17-2.21), age &ge;80 years (PR 4.15; 95%CI 2.65-6.50), underweight (PR 1.90; 95%CI 1.23-2.93), diabetes mellitus (PR 1.80; 95%CI 1.20-2.73), and hospitalization in the past year (PR 2.00; 95%CI 1.36-2.91) were significantly associated with probable sarcopenia. One in five rural older adults have probable sarcopenia. Older adults living in rural areas need frequent measurements of muscle strength, and greater investments should be made to minimize the physical disability caused by sarcopenia among this population.

A new species of the Cambeva variegata group (Siluriformes: Trichomycteridae) from the Serra do Espinhaço, south-eastern Brazil, under severe risk of extinction

The mountain ranges of southeastern and southern Brazil are inhabited by a great diversity of catfishes of the genus Cambeva. The Cambeva variegata group, diagnosed by having a prominent skin crest similar to an adipose fin, an interrupted supraorbital laterosensory canal, with an additional supraorbital S4 pore, and a relatively small premaxilla with an accentuated constriction on its lateral portion, occurs in a broad area of south-eastern Brazil, mostly within the savannah-like Cerrado vegetation at the northern-most part of the genus distribution. The new species described here was collected in streams of the Rio das Velhas drainage, Rio São Francisco basin, draining the Serra do Espinhaço. The new species is diagnosed by having more interopercular odontodes and a combination of morphometric data, colour pattern, relative dorsal-fin origin and vertebra position, and-fin-ray morphology. Field studies indicate that the two localities where the new species occur are being dramatically affected by negative human impacts, putting it in severe risk of extinction.