#DeOlhoNosCorais: a polygonal annotated dataset to optimize coral monitoring.

Corals are colonial animals within the Phylum Cnidaria that form coral reefs, playing a significant role in marine environments by providing habitat for fish, mollusks, crustaceans, sponges, algae, and other organisms. Global climate changes are causing more intense and frequent thermal stress events, leading to corals losing their color due to the disruption of a symbiotic relationship with photosynthetic endosymbionts. Given the importance of corals to the marine environment, monitoring coral reefs is critical to understanding their response to anthropogenic impacts. Most coral monitoring activities involve underwater photographs, which can be costly to generate on large spatial scales and require processing and analysis that may be time-consuming. The Marine Ecology Laboratory (LECOM) at the Federal University of Rio Grande do Norte (UFRN) developed the project "#DeOlhoNosCorais" which encourages users to post photos of coral reefs on their social media (Instagram) using this hashtag, enabling people without previous scientific training to contribute to coral monitoring. The laboratory team identifies the species and gathers information on coral health along the Brazilian coast by analyzing each picture posted on social media. To optimize this process, we conducted baseline experiments for image classification and semantic segmentation. We analyzed the classification results of three different machine learning models using the Local Interpretable Model-agnostic Explanations (LIME) algorithm. The best results were achieved by combining EfficientNet for feature extraction and Logistic Regression for classification. Regarding semantic segmentation, the U-Net Pix2Pix model produced a pixel-level accuracy of 86%. Our results indicate that this tool can enhance image selection for coral monitoring purposes and open several perspectives for improving classification performance. Furthermore, our findings can be expanded by incorporating other datasets to create a tool that streamlines the time and cost associated with analyzing coral reef images across various regions.

Oligomeric α-Synuclein induces skin degeneration in reconstructed human epidermis.

Aged and photoaged skin exhibit fine wrinkles that are signs of epidermal inflammation and degeneration. It has been shown that healthy elderly skin expresses amyloidogenic proteins, including α-Synuclein, which are known to oligomerize and trigger inflammation and neurodegeneration. However, little is known about their putative role in skin physiology and sensitivity. To unravel this possible role, we investigated the impact of oligomeric α-Synuclein (Oα-Syn) in 2D and 3D keratinocyte human models. Exogenous Oα-Syn caused degeneration of reconstructed human epidermis (RHE) by diminishing proliferation and thickness of the stratum basale. Oα-Syn also increased NF-kB nuclear translocation in keratinocytes and triggered inflammation in the RHE, by increasing expression of interleukin-1ß and tumor necrosis factor-alpha, and the release of tumor necrosis factor-alpha in a time-dependent manner. Dexamethasone and an IL-1ß inhibitor partially diminished RHE degeneration caused by Oα-Syn. These findings suggest that Oα-Syn induces epidermal inflammation and decreases keratinocyte proliferation, and therefore might contribute to epidermal degeneration observed in human skin aging.

WIN 55,212-2 shows anti-inflammatory and survival properties in human iPSC-derived cardiomyocytes infected with SARS-CoV-2.

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which can infect several organs, especially impacting respiratory capacity. Among the extrapulmonary manifestations of COVID-19 is myocardial injury, which is associated with a high risk of mortality. Myocardial injury, caused directly or indirectly by SARS-CoV-2 infection, can be triggered by inflammatory processes that lead to damage to the heart tissue. Since one of the hallmarks of severe COVID-19 is the "cytokine storm", strategies to control inflammation caused by SARS-CoV-2 infection have been considered. Cannabinoids are known to have anti-inflammatory properties by negatively modulating the release of pro-inflammatory cytokines. Herein, we investigated the effects of the cannabinoid agonist WIN 55,212-2 (WIN) in human iPSC-derived cardiomyocytes (hiPSC-CMs) infected with SARS-CoV-2. WIN did not modify angiotensin-converting enzyme II protein levels, nor reduced viral infection and replication in hiPSC-CMs. On the other hand, WIN reduced the levels of interleukins six, eight, 18 and tumor necrosis factor-alpha (TNF-α) released by infected cells, and attenuated cytotoxic damage measured by the release of lactate dehydrogenase (LDH). Our findings suggest that cannabinoids should be further explored as a complementary therapeutic tool for reducing inflammation in COVID-19 patients.

Non-permissive SARS-CoV-2 infection in human neurospheres.

Coronavirus disease 2019 (COVID-19) was initially described as a viral infection of the respiratory tract. It is now known, however, that several other organs are affected, including the brain. Neurological manifestations such as stroke, encephalitis, and psychiatric conditions have been reported in COVID-19 patients, but the neurotropic potential of the virus is still debated. Herein, we sought to investigate SARS-CoV-2 infection in human neural cells. We demonstrated that SARS-CoV-2 infection of neural tissue is non-permissive, however, it can elicit inflammatory response and cell damage. These findings add to the hypothesis that most of the neural damage caused by SARS-CoV-2 infection is due to a systemic inflammation leading to indirect harmful effects on the central nervous system despite the absence of local viral replication.

Non-permissive SARS-CoV-2 infection in human neurospheres.

Coronavirus disease 2019 (COVID-19) was initially described as a viral infection of the respiratory tract. It is now known, however, that several other organs are affected, including the brain. Neurological manifestations such as stroke, encephalitis, and psychiatric conditions have been reported in COVID-19 patients, but the neurotropic potential of the virus is still debated. Herein, we sought to investigate SARS-CoV-2 infection in human neural cells. We demonstrated that SARS-CoV-2 infection of neural tissue is non-permissive, however, it can elicit inflammatory response and cell damage. These findings add to the hypothesis that most of the neural damage caused by SARS-CoV-2 infection is due to a systemic inflammation leading to indirect harmful effects on the central nervous system despite the absence of local viral replication.

Inhibition of SARS-CoV-2 infection in human iPSC-derived cardiomyocytes by targeting the Sigma-1 receptor disrupts cytoarchitecture and beating.

SARS-CoV-2 infects cardiac cells and causes heart dysfunction. Conditions such as myocarditis and arrhythmia have been reported in COVID-19 patients. The Sigma-1 receptor (S1R) is a ubiquitously expressed chaperone that plays a central role in cardiomyocyte function. S1R has been proposed as a therapeutic target because it may affect SARS-CoV-2 replication; however, the impact of the inhibition of S1R in human cardiomyocytes remains to be described. In this study, we investigated the consequences of S1R inhibition in iPSC-derived human cardiomyocytes (hiPSC-CM). SARS-CoV-2 infection in hiPSC-CM was productive and reduced cell survival. S1R inhibition decreased both the number of infected cells and viral particles after 48 hours. S1R inhibition also prevented the release of pro-inflammatory cytokines and cell death. Although the S1R antagonist NE-100 triggered those protective effects, it compromised cytoskeleton integrity by downregulating the expression of structural-related genes and reducing beating frequency. Our findings suggest that the detrimental effects of S1R inhibition in human cardiomyocytes' integrity may abrogate its therapeutic potential against COVID and should be carefully considered.

Identification of arthropathy and myopathy of the temporomandibular syndrome by biomechanical facial features.

BACKGROUND: Temporomandibular disorders (TMDs) are pathological conditions affecting the temporomandibular joint and/or masticatory muscles. The current diagnosis of TMDs is complex and multi-factorial, including questionnaires, medical testing and the use of diagnostic methods, such as computed tomography and magnetic resonance imaging. The evaluation, like the mandibular range of motion, needs the experience of the professional in the field and as such, there is a probability of human error when diagnosing TMD. The aim of this study is therefore to develop a method with infrared cameras, using the maximum range of motion of the jaw and four types of classifiers to help professionals to classify the pathologies of the temporomandibular joint (TMJ) and related muscles in a quantitative way, thus helping to diagnose and follow up on TMD. METHODS: Forty individuals were evaluated and diagnosed using the diagnostic criteria for temporomandibular disorders (DC/TMD) scale, and divided into three groups: 20 healthy individuals (control group CG), 10 individuals with myopathies (MG), 10 individuals with arthropathies (AG). A quantitative assessment was carried out by motion capture. The TMJ movement was captured with camera tracking markers mounted on the face and jaw of each individual. Data was exported and analyzed using a custom-made software. The data was used to identify and place each participant into one of three classes using the K-nearest neighbor (KNN), Random Forest, Naïve Bayes and Support Vector Machine algorithms. RESULTS: Significant precision and accuracy (over 90%) was reached by KNN when classifying the three groups. The other methods tested presented lower values of sensitivity and specificity. CONCLUSION: The quantitative TMD classification method proposed herein has significant precision and accuracy over the DC/TMD standards. However, this should not be used as a standalone tool but as an auxiliary method for diagnostic TMDs.

Kinematic and electromyographic analysis of school children gait with and without load in the backpack

AbstractIntroduction: Excessive load on the backpacks can lead to musculoskeletal injuries and gait alterations. The objective of this study was to analyze the electromyographic (EMG) activity in association to the kinematic during the stance and balance phases of gait performed with and without the use of the backpack. Methods Twelve volunteers have executed a gait cycle in 3 tasks: without the school backpack (SM), with a backpack with load equivalent to 10% (M10) and 20% (M20) of the body weight (BW). It was evaluated the ankle, knee and hip angular excursion (AE), linear displacement (LD) of the toe and ankle, knee, hip, shoulder, head and EMG activity of the tibialis anterior (TA), vastus medialis (VM), rectus abdominis (RA), gastrocnemius lateral (GL), biceps femoris (BF) and spinal erector (EE) muscles. Results In the LD in the stance phase there was an AP increase for the toe and ankle, hip and head (p<0.043). In the balance phase for VT (vertical) direction, the shoulder presented a smaller displacement as well as the toe, ankle, knee, hip, shoulder and head in the ML direction. In the AP direction, the toe displacement was smaller as well as the ankle (p < 0.038). The AE in both phases was smaller for the hip (p <0.006). In the balance phase the IEMG was higher for the RA (p = 0.034). Conclusion These results suggest that the transport of school backpacks with loads of more than 10%BW causes changes in the kinematic and in the muscular recruitment pattern.

Prevalência do diabetes mellitus associado ao estresse ocupacional em trabalhadores bancários, Minas Gerais, Brasil / Prevalence of diabetes mellitus associated to occupational stress in bank employees, Minas Gerais, Brazil / Prevalencia de la diabetes mellitus asociada al estrés ocupacional en trabajadores bancarios, Minas Gerais, Brasil

INTRODUÇÃO: Estresse ocupacional é considerado fator de risco para o diabetes mellitus. Bancários são submetidos constantemente ao estresse, podendo alterar os níveis glicêmicos e lipêmicos. Objetivo: analisar as alterações nos níveis de glicemia e associa-las ao estresse ocupacional em bancários. MATERIAIS E MÉTODOS: Trata-se de pesquisa descritiva e analítica. Avaliou-se glicemia de jejum capilar, aferição da medida da pressão arterial, peso, altura, circunferência abdominal, cálculo do Índice de Massa Corpórea, aplicação de questionários de perfil diabético e de teste de Inventário de Sintomas de Stress de Lipp, para as análises das fases de estresse. RESULTADOS: Foram16 voluntários, 12 homens, com idade média de 34,92 ± 3,14 anos e 4 mulheres, 30,25 ± 2,63 anos. Entre os homens, 91,60% apresentaram glicemia de jejum alterada (115,71±2,01mg/dl), 41,60% com sobrepeso (28,04±0,26kg/m2) e 16,88% com obesidade (32,35±0,65kg/m2). 58,33% dos homens estavam com estresse, sendo que 85,71% desses homens estavam na fase de resistência e 14,28% na fase de exaustão. Nas mulheres, 75% apresentaram glicemia de jejum alterada (126,44±5,49mg/dl), 25% tinham sobrepeso (26,93±0,13kg/m2) e 25% obesidade (32,30 kg/m2). Na avaliação do estresse foram encontrados 75% das mulheres com estresse, estando todas na fase de resistência. DISCUSSÃO: São necessárias intervenções no ambiente de trabalho que propicia um processo de adoecimento. CONCLUSÕES: Bancários que se encontravam em alguma fase de estresse, apresentavam níveis glicêmicos alterados, sinalizando uma possível ação do cortisol em sua rotina diária.

INTRODUCTION: Occupational stress is considered a risk factor for diabetes mellitus. Bank workers are constantly exposed to stress, which could alter their glycemic and lipemic levels. OBJECTIVE: The objective of this work was to analyze alterations in glycemia levels and associate them to occupational stress in bank employees. MATERIALS AND METHODS: This was a descriptive and analytic research. The study evaluated capillary fasting glycemia, gauged blood pressure, weight, height, and waist circumference measurements; calculated the body mass index; application of diabetic profile questionnaires, and the Lipp Stress Symptom Inventory test to analyze the stress phases. RESULTS: The study included 16 volunteers, 12 men, with a mean age of 34.92 ± 3.14 years and 4 women, 30.25 ± 2.63 years. Among the men, 91.60% had altered fasting glycemia (115.71±2.01 mg/dl); 41.60% were overweight (28.04±0.26 kg/m2); and 16.88% were obese (32.35±0.65 kg/m2). Reportedly, 58.33% of the men had stress, with 85.71% of these men in the resistance phase and 14.28% in the exhaustion phase. Among the women, 75% had altered fasting glycemia (126.44±5.49 mg/dl); 25% were overweight (26.93±0.13kg/m2); and 25% were obese (32.30 kg/m2). The stress assessment revealed that 75% of the women were under stress, all in the resistance phase. DISCUSSION: Interventions are needed in the workplace that propitiates an illness process. CONCLUSIONS: Bank workers at some stage of stress had altered glycemic levels, signaling a possible cortisol action in their daily routine.

INTRODUCCIÓN: El estrés ocupacional es considerado un factor de riesgo para la diabetes mellitus. Bancarios se someten constantemente al estrés, pudiendo alterar los niveles glucémicos y lipémicos. OBJETIVO: Analizar los cambios en los niveles de glucemia y asociarlos al estrés ocupacional en bancarios. MATERIALES Y MÉTODOS: Se trata de una investigación descriptiva y analítica. Se evaluó la glucemia capilar en ayuno, la toma de la medida de la presión arterial, peso, altura, circunferencia abdominal, cálculo del Índice de Masa Corporal, aplicación de cuestionarios de perfil diabético y de prueba de Inventario de Síntomas de Stress de Lipp, para los análisis de las fases de estrés. RESULTADOS: Fueron16 voluntarios, 12 hombres, con una edad media de 34.92 ± 3.14 años y 4 mujeres, 30.25 ± 2.63 años. Entre los hombres, el 91.60% presentó glucemia de ayuno alterada (115.71 ± 2.01mg / dl), el 41.60% sobrepeso (28.04 ± 0.26 kg/m2) y el 16.88% obesidad (32.35 ± 0,65kg/m2). El 58.33% de los hombres estaban con estrés, mientras que el 85.71% de estos hombres estaban en la fase de resistencia y el 14.28% en la fase de agotamiento. En las mujeres, el 75% presentó glucemia de ayuno alterada (126.44 ± 5.49mg/dl), el 25% sobrepeso (26.93 ± 0.13 kg/m2) y el 25% obesidad (32.30 kg/m2). En la evaluación del estrés se encontró el 75% de las mujeres con estrés, estando todas en la fase de resistencia. DISCUSIÓN: Se necesitan intervenciones en el ambiente de trabajo que favorece un proceso de enfermedad. CONCLUSIONES: Bancarios que se encontraban en alguna fase de estrés, presentaban niveles glucémicos alterados, señalando una posible acción del cortisol en su rutina diaria.

A specialized motion capture system for real-time analysis of mandibular movements using infrared cameras.

BACKGROUND: In the last years, several methods and devices have been proposed to record the human mandibular movements, since they provide quantitative parameters that support the diagnosis and treatment of temporomandibular disorders. The techniques currently employed suffer from a number of drawbacks including high price, unnatural to use, lack of support for real-time analysis and mandibular movements recording as a pure rotation. In this paper, we propose a specialized optical motion capture system, which causes a minimum obstruction and can support 3D mandibular movement analysis in real-time. METHODS: We used three infrared cameras together with nine reflective markers that were placed at key points of the face. Some classical techniques are suggested to conduct the camera calibration and three-dimensional reconstruction and we propose some specialized algorithms to automatically recognize our set of markers and track them along a motion capture session. RESULTS: To test the system, we developed a prototype software and performed a clinical experiment in a group of 22 subjects. They were instructed to execute several movements for the functional evaluation of the mandible while the system was employed to record them. The acquired parameters and the reconstructed trajectories were used to confirm the typical function of temporomandibular joint in some subjects and to highlight its abnormal behavior in others. CONCLUSIONS: The proposed system is an alternative to the existing optical, mechanical, electromagnetic and ultrasonic-based methods, and intends to address some drawbacks of currently available solutions. Its main goal is to assist specialists in diagnostic and treatment of temporomandibular disorders, since simple visual inspection may not be sufficient for a precise assessment of temporomandibular joint and associated muscles.

Xeno-free production of human embryonic stem cells in stirred microcarrier systems using a novel animal/human-component-free medium.

Currently, stem cell research faces a major bottleneck related to the low efficiency of methods to produce large quantities of human embryonic stem cells (ESC) for use in clinical trials. Most culture media currently employed for human ESC cultivation contain animal compounds, and cells are grown in static flasks. Besides the immediate contamination with nonhuman compounds, cell expansion in flasks tends to be laborious and nonefficient. Here we cultured human ESC in stirred microcarrier (MC) systems using an animal/human-component-free medium, to overcome both issues. The method developed to culture cells on suspended beads combined the use of polymeric MCs in stirred vessels with an optimized culture medium free of supplements of animal and human origin. This approach generated approximately 160 million cells within 6 days, which were shown to remain pluripotent. The process developed herein provides a step forward toward therapy due to the economic advantages in the production of human ESC and to their consequent low immunogenic potential.

Quantification of physiological kinetic tremor and its correlation with aging.

Tremor is the most common movement disorder characterized by repetitive and stereotyped movements. The analysis of hand-drawing movements is commonly used in the evaluation of patients with tremor. The data collection conducted under kinetic conditions and while performing a voluntary movement highlights the kinetic tremor. Most investigations on tremor attempt to understand its relation to neuromuscular dysfunctions. Therefore, there is a lack of studies that aim to investigate the complex relation between the physiological tremor and aging, especially in kinetic conditions. In this context, the main motivation of this research was to generalize the results obtained in Almeida et al., a study that quantified age-related changes in the kinetic tremor of clinically healthy individuals. For this, a number of features extracted from tremor activity, obtained from digitized drawings of Archimedes' spirals, were analyzed. The analyses followed the sequence: Linearization of the Archimedes' spiral; Estimate of tremor activity; Data pre-processing; Feature extraction from the tremor activity; and Application of Linear Discriminant Analysis (LDA) technique as described in Almeida et al.. The generalization of the obtained results showed that the method based on LDA allows for a linear correlation between physiological kinetic tremor and aging.

CK2 phosphorylation of Schistosoma mansoni HMGB1 protein regulates its cellular traffic and secretion but not its DNA transactions.

BACKGROUND: The helminth Schistosoma mansoni parasite resides in mesenteric veins where fecundated female worms lay hundred of eggs daily. Some of the egg antigens are trapped in the liver and induce a vigorous granulomatous response. High Mobility Group Box 1 (HMGB1), a nuclear factor, can also be secreted and act as a cytokine. Schistosome HMGB1 (SmHMGB1) is secreted by the eggs and stimulate the production of key cytokines involved in the pathology of schistosomiasis. Thus, understanding the mechanism of SmHMGB1 release becomes mandatory. Here, we addressed the question of how the nuclear SmHMGB1 can reach the extracellular space. PRINCIPAL FINDINGS: We showed in vitro and in vivo that CK2 phosphorylation was involved in the nucleocytoplasmic shuttling of SmHMGB1. By site-directed mutagenesis we mapped the two serine residues of SmHMGB1 that were phosphorylated by CK2. By DNA bending and supercoiling assays we showed that CK2 phosphorylation of SmHMGB1 had no effect in the DNA binding activities of the protein. We showed by electron microscopy, as well as by cell transfection and fluorescence microscopy that SmHMGB1 was present in the nucleus and cytoplasm of adult schistosomes and mammalian cells. In addition, we showed that treatments of the cells with either a phosphatase or a CK2 inhibitor were able to enhance or block, respectively, the cellular traffic of SmHMGB1. Importantly, we showed by confocal microscopy and biochemically that SmHMGB1 is significantly secreted by S. mansoni eggs of infected animals and that SmHMGB1 that were localized in the periovular schistosomotic granuloma were phosphorylated. CONCLUSIONS: We showed that secretion of SmHMGB1 is regulated by phosphorylation. Moreover, our results suggest that egg-secreted SmHMGB1 may represent a new egg antigen. Therefore, the identification of drugs that specifically target phosphorylation of SmHMGB1 might block its secretion and interfere with the pathogenesis of schistosomiasis.

Human Dental Pulp Cells: A New Source of Cell Therapy in a Mouse Model of Compressive Spinal Cord Injury

Strategies aimed at improving spinal cord regeneration after trauma are still challenging neurologists andneuroscientists throughout the world. Many cell-based therapies have been tested, with limited success in termsof functional outcome. In this study, we investigated the effects of human dental pulp cells (HDPCs) in a mousemodel of compressive spinal cord injury (SCI). These cells present some advantages, such as the ease of theextraction process, and expression of trophic factors and embryonic markers from both ecto-mesenchymal andmesenchymal components. Young adult female C57/BL6 mice were subjected to laminectomy at T9 andcompression of the spinal cord with a vascular clip for 1 min. The cells were transplanted 7 days or 28 days afterthe lesion, in order to compare the recovery when treatment is applied in a subacute or chronic phase. Weperformed quantitative analyses of white-matter preservation, trophic-factor expression and quantification, andultrastructural and functional analysis. Our results for the HDPC-transplanted animals showed better whitematterpreservation than the DMEM groups, higher levels of trophic-factor expression in the tissue, better tissueorganization, and the presence of many axons being myelinated by either Schwann cells or oligodendrocytes, inaddition to the presence of some healthy-appearing intact neurons with synapse contacts on their cell bodies. Wealso demonstrated that HDPCs were able to express some glial markers such as GFAP and S-100. The functionalanalysis also showed locomotor improvement in these animals. Based on these findings, we propose that HDPCsmay be feasible candidates for therapeutic intervention after SCI and central nervous system disorders inhumans.

Human dental pulp cells: a new source of cell therapy in a mouse model of compressive spinal cord injury.

Strategies aimed at improving spinal cord regeneration after trauma are still challenging neurologists and neuroscientists throughout the world. Many cell-based therapies have been tested, with limited success in terms of functional outcome. In this study, we investigated the effects of human dental pulp cells (HDPCs) in a mouse model of compressive spinal cord injury (SCI). These cells present some advantages, such as the ease of the extraction process, and expression of trophic factors and embryonic markers from both ecto-mesenchymal and mesenchymal components. Young adult female C57/BL6 mice were subjected to laminectomy at T9 and compression of the spinal cord with a vascular clip for 1 min. The cells were transplanted 7 days or 28 days after the lesion, in order to compare the recovery when treatment is applied in a subacute or chronic phase. We performed quantitative analyses of white-matter preservation, trophic-factor expression and quantification, and ultrastructural and functional analysis. Our results for the HDPC-transplanted animals showed better white-matter preservation than the DMEM groups, higher levels of trophic-factor expression in the tissue, better tissue organization, and the presence of many axons being myelinated by either Schwann cells or oligodendrocytes, in addition to the presence of some healthy-appearing intact neurons with synapse contacts on their cell bodies. We also demonstrated that HDPCs were able to express some glial markers such as GFAP and S-100. The functional analysis also showed locomotor improvement in these animals. Based on these findings, we propose that HDPCs may be feasible candidates for therapeutic intervention after SCI and central nervous system disorders in humans.

Índice de cobertura vegetal e sua modelagem para cultivares de soja no sul de Minas Gerais / Index of vegetal cover and its modeling for soybean cultivars in the south of Minas Gerais

A cobertura vegetal do solo é decisiva para redução dos efeitos erosivos do impacto direto das gotas de chuva na superfície do solo. Desta forma, objetivou-se com este estudo determinar o índice de cobertura vegetal (CV) e desenvolver modelos para sua estimativa para a cultura da soja, usando os atributos climáticos no período de chuvas intensas no Sul de Minas Gerais. As determinações da CV foram feitas semanalmente, na área experimental do Departamento de Ciência do Solo, Universidade Federal de Lavras, no período de novembro de 1999 a maio de 2000, em 28 cultivares de soja com potencial para cultivo nesta região. Para avaliação da cobertura vegetal foi utilizada a metodologia descrita por Stocking (1988). Na modelagem procurou-se relacionar a CV com os valores acumulados dos seguintes atributos climáticos: temperatura média (Tmed), precipitação (PREC) e umidade relativa do ar (UR). Os valores de cobertura vegetal apresentaram uma amplitude de variação de 56 a 83 por cento, sendo BR 162, LO 12 L e M. Soy 108 as cultivares mais eficientes e FT Abyara e Tucano as menos eficientes. O hábito diferencial de crescimento das cultivares ajuda a explicar esse comportamento. O modelo ajustado adequado para estimativa da CV foi: CV = 116589,976 + 0,422 . Tmed + 0,132 . PREC - 0,095 . UR + 0,000024 . Tmed², R² = 0,99 (P < 0,01). A determinação da CV nas diferentes fases de desenvolvimento da cultura é de grande importância, uma vez que seu estabelecimento coincide com o período de maior potencial erosivo das chuvas na região estudada.

Vegetal cover of soil is decisive to reduce the erosive effects of direct impact of raindrops on the soil surface. Therefore, the objective of this study was to determine the vegetal cover (CC) index and to develop models to estimate it for soybean cultivars, using climatic attributes in the period of intense rains in the South of the State of Minas Gerais in Brazil. CC was measured weekly in the experimental area of the Department of Soil Science, Federal University of Lavras, from November 1999 to May 2000, for 28 soybean cultivars with yield potential in this region. To evaluate the vegetal cover, the method described by Stocking (1988) was used. In the modeling, CC was related with the accumulated values of following climatic attributes: medium temperature (Tmed), precipitation (PREC), and relative humidity of the air (RH). Vegetal cover values presented an amplitude from 56 to 83 percent, being BR 162, LO 12 L and M. Soy 108, the more efficient cultivars, and the FT Abyara and Tucano, the least efficient ones. The differential growth habit of the cultivars helps to explain this behavior. The best adjusted model for the estimative of CC was: CC = 116589.976 + 0.422, Tmed + 0.132, PREC - 0.095, RH + 0.000024 Tmed², R² = 0.99 (P < 0.01). The knowledge of CC for different development phases of the crop is of great importance, taking into account that its establishment time coincides with the highest erosive potential of the rains in the studied region.

Cannabinoids modulate cell survival in embryoid bodies.

ESCs (embryonic stem cells) are potentially able to replace damaged cells in animal models of neural pathologies such as Parkinson's disease, stroke and spinal cord lesions. Nevertheless, many issues remain unsolved regarding optimal culturing procedures for these cells. For instance, on their path to differentiation in vitro, which usually involves the formation of EBs (embryoid bodies), they may present chromosomal instability, loss of pluripotency or simply die. Therefore, finding strategies to increase the survival of cells within EBs is of great interest. Cannabinoid receptors have many roles in the physiology of the adult body, but little is known about their role in the biology of ESCs. Herein, we investigated how two cannabinoid receptors, CB1 and CB2, may affect the outcome of ESCs aggregated as EBs. RT-PCR (reverse transcriptase-PCR) revealed that EBs expressed both CB1 and CB2 receptors. Aggregation of ESCs into EBs followed by 2-day incubation with a CB1/CB2 agonist reduced cell death by approximately 45%, which was reversed by a CB1 antagonist. A specific CB2 agonist also reduced cell death by approximately 20%. These data indicate that both cannabinoid receptors, CB1 and CB2, are involved in reducing cell death in EBs mediated by exogenous cannabinoids. No increase in proliferation, neural differentiation or changes in chromosomal stability was observed. This study indicates that cannabinoid signalling is functionally implicated in the biology of differentiating ESCs, being the first to show that activation of cannabinoid receptors is able to increase cell viability via reduction of cell death rate in EBs.

Schistosoma mansoni: SmLIMPETin, a member of a novel family of invertebrate-only regulatory proteins.

Eukaryotic LIM domain proteins contain zinc finger forming motifs rich in cysteine and histidine that enable them to interact with other proteins. A cDNA clone isolated from an adult schistosome cDNA library revealed a sequence that coded for a novel class of proteins bearing 6 LIM domains and an N-terminal PET domain, SmLIMPETin. Phylogeny reconstruction of SmLIMPETin and comparison of its sequence to invertebrate homologues and to the vertebrate four-and-a-half LIM domains protein family (FHLs), uncovered a novel LIM domain protein family, the invertebrate LIM and PET domain protein family (LIMPETin). Northern blots, RT-PCR and Western blot showed that SmLIMPETin gene was less expressed in sexually mature adult females compared to sexually immature adult females and sexually mature and immature adult males, and not expressed in schistosomula.