Risk assessment of ionizing radiation and radiological thresholds to compound an environmental baseline for the unconventional gas industry.

The exploration of unconventional hydrocarbons may be very effective in promoting economic development and confronting energy crisis around the world. However, the environmental risks associated with this practice might be an impediment if not adequately dimensioned. In this context, naturally occurring radioactive materials and ionizing radiation are sensitive aspects in the unconventional gas industry that may compromise the environmental sustainability of gas production and they should be properly monitored. This paper provides a radioecological assessment of the São Francisco Basin (Brazil) as part of an environmental baseline evaluation regarding the Brazilian potential for exploring its unconventional gas reserves. Eleven and thirteen samples of surface waters and groundwater were analyzed for gross alpha and beta using a gas flow proportional counter. A radiological background range was proposed using the ± 2 Median Absolute Deviation method. Using geoprocessing tools, the annual equivalent doses and lifetime cancer risk indexes were spatialized. Gross alpha and beta background thresholds in surface water ranged from 0.04-0.40 Bq L-1 to 0.17-0.46 Bq L-, respectively. Groundwater radiological background varies from 0.006-0.81 Bq L-1 to 0.06-0.72 Bq L-1 for gross alpha and beta, respectively. All environmental indexes are relatively higher in the south of the basin, probably a direct response to the local volcanic formations. Traçadal fault and local gas seepages might also influence the gross alpha and beta distribution. All samples have radiological indexes below the environmental thresholds, and should remain at acceptable levels with the development of the unconventional gas industry in Brazil.

Modeling functional network topology following stroke through graph theory: functional reorganization and motor recovery prediction.

The study of functional reorganization following stroke has been steadily growing supported by advances in neuroimaging techniques, such as functional magnetic resonance imaging (fMRI). Concomitantly, graph theory has been increasingly employed in neuroscience to model the brain's functional connectivity (FC) and to investigate it in a variety of contexts. The aims of this study were: 1) to investigate the reorganization of network topology in the ipsilesional (IL) and contralesional (CL) hemispheres of stroke patients with (motor stroke group) and without (control stroke group) motor impairment, and 2) to predict motor recovery through the relationship between local topological variations of the functional network and increased motor function. We modeled the brain's FC as a graph using fMRI data, and we characterized its interactions with the following graph metrics: degree, clustering coefficient, characteristic path length, and betweenness centrality (BC). For both patient groups, BC yielded the largest variations between the two analyzed time points, especially in the motor stroke group. This group presented significant correlations (P<0.05) between average BC changes and the improvements in upper-extremity Fugl-Meyer (UE-FM) scores at the primary sensorimotor cortex and the supplementary motor area for the CL hemisphere. These regions participate in processes related to the selection, planning, and execution of movement. Generally, higher increases in average BC over these areas were related to larger improvements in UE-FM assessment. Although the sample was small, these results suggest the possibility of using BC as an indication of brain plasticity mechanisms following stroke.

Modeling functional network topology following stroke through graph theory: functional reorganization and motor recovery prediction

The study of functional reorganization following stroke has been steadily growing supported by advances in neuroimaging techniques, such as functional magnetic resonance imaging (fMRI). Concomitantly, graph theory has been increasingly employed in neuroscience to model the brain's functional connectivity (FC) and to investigate it in a variety of contexts. The aims of this study were: 1) to investigate the reorganization of network topology in the ipsilesional (IL) and contralesional (CL) hemispheres of stroke patients with (motor stroke group) and without (control stroke group) motor impairment, and 2) to predict motor recovery through the relationship between local topological variations of the functional network and increased motor function. We modeled the brain's FC as a graph using fMRI data, and we characterized its interactions with the following graph metrics: degree, clustering coefficient, characteristic path length, and betweenness centrality (BC). For both patient groups, BC yielded the largest variations between the two analyzed time points, especially in the motor stroke group. This group presented significant correlations (P<0.05) between average BC changes and the improvements in upper-extremity Fugl-Meyer (UE-FM) scores at the primary sensorimotor cortex and the supplementary motor area for the CL hemisphere. These regions participate in processes related to the selection, planning, and execution of movement. Generally, higher increases in average BC over these areas were related to larger improvements in UE-FM assessment. Although the sample was small, these results suggest the possibility of using BC as an indication of brain plasticity mechanisms following stroke.

On the (in)efficacy of motor imagery training without feedback and event-related desynchronizations considerations.

Motor imagery (MI) constitutes a recurrent strategy for signals generation in brain-computer interfaces (BCIs) - systems that aim to control external devices by directly associating brain responses to distinct commands. Although great improvement has been achieved in MI-BCIs performance over recent years, they still suffer from inter- and intra-subject variability issues. As an attempt to cope with this, some studies have suggested that MI training should aid users to appropriately modulate their response for BCI usage: generally, this training is performed based on the sensorimotor rhythms' modulation over the primary sensorimotor cortex (PMC), with the signal being feedbacked to the user. Nonetheless, recent studies have revisited the actual involvement of the PMC into MI, and little to no attention has been devoted to understanding the participation of other cortical areas into training protocols. Therefore, in this work, our aim was to analyze the response induced by hands MI of 10 healthy subjects in the form of event-related desynchronizations (ERDs) and to assess whether features from beyond the PMC might be useful for hands MI classification. We investigated how this response occurs for distinct frequency intervals between 7-30 Hz, and ex0plored changes in their evocation pattern across 12 MI training sessions without feedback. Overall, we found that ERD patterns occur differently for the frequencies encompassed by the µ and ß bands, with its evocation being favored for the first band. Over time, the no-feedback approach was inefficient to aid in enhancing ERD evocation (EO). Moreover, to some extent, EO tends to decrease over blocks within a given run, and runs within an MI session, but remains stable within an MI block. We also found that the C3/C4 pair is not necessarily optimal for data classification, and both spectral and spatial subjects' specificities should be considered when designing training protocols.

Apex predator and the cyclic competition in a rock-paper-scissors game of three species.

This work deals with the effects of an apex predator on the cyclic competition among three distinct species that follow the rules of the rock-paper-scissors game. The investigation develops standard stochastic simulations but is motivated by a procedure which is explained in the work. We add the apex predator as the fourth species in a system that contains three species that evolve following the standard rules of migration, reproduction, and predation, and study how the system evolves in this new environment, in comparison with the case in the absence of the apex predator. The results show that the apex predator engenders the tendency to spread uniformly in the lattice, contributing to destroy the spiral patterns, keeping biodiversity but diminishing the average size of the clusters of the species that compete cyclically.

Exploring disparities in incidence and mortality rates of breast and gynecologic cancers according to the Human Development Index in the Pan-American region.

OBJECTIVE: To evaluate whether a country's Human Development Index (HDI) can help explain the differences in the country's breast cancer and gynecological cancer incidence and mortality rates in the Pan-American region. STUDY DESIGN: Ecological analysis. METHODS: Pan-American region countries with publicly available data both in GLOBOCAN 2012 and the United Nations Development Report 2012 were included (n = 28). Incidence and mortality rates age-standardized per 100,000 were natural log-transformed for breast cancer, ovarian cancer, corpus uteri cancer, and cervical cancer. The mortality-to-incidence ratio (MIR) was calculated for each site. Pearson's correlation test and a simple linear regression were performed. RESULTS: The HDI showed a positive correlation with breast cancer and ovarian cancer incidence and mortality rates, respectively, and a negative correlation with cervical cancer incidence and mortality rates. The HDI and corpus uteri cancer showed no association. MIR and the HDI showed a negative correlation for all tumor types except ovarian cancer. An increment in 1 HDI unit leads to changes in cancer rates: in breast cancer incidence ß = 4.03 (95% confidence interval [CI] 2.61; 5.45) P < 0.001, breast cancer mortality ß = 1.76 (95% CI 0.32; 3.21) P = 0.019, and breast cancer-MIR ß = -0.705 (95% CI 0.704; 0.706) P < 0.001; in cervical cancer incidence ß = -3.28 (95% CI -4.78; -1.78) P < 0.001, cervical cancer mortality ß = -4.63 (95% CI -6.10; -3.17) P < 0.001, and cervical cancer-MIR ß = -1.35 (95% CI -1.83; -0.87) P < 0.001; in ovarian cancer incidence ß = 3.26 (95% CI 1.78; 4.75) P < 0.001, ovarian cancer mortality ß = 1.82 (95% CI 0.44; 3.20) P = 0.012, and ovarian cancer-MIR ß = 5.10 (95% CI 3.22; 6.97) P < 0.001; in corpus uteri cancer incidence ß = 2.37 (95% CI -0.33; 5.06) P = 0.83, corpus uteri cancer mortality ß = 0.68 (95% CI -2.68; 2.82) P = 0.96, and corpus uteri cancer-MIR ß = -2.30 (95% CI -3.19; -1.40) P < 0.001. CONCLUSIONS: A country's HDI should be considered to understand disparities in breast cancer and gynecological cancer in the Pan-American region.

Vitamin E nanoemulsion activity on stored red blood cells.

BACKGROUND: Stored red blood cells (RBCs) undergo numerous changes that have been termed RBC storage lesion, which can be related to oxidative damage. Vitamin E is an important antioxidant, acting on cell lipids. Thus, this study aimed to investigate vitamin E activity on stored RBCs. METHODS: We prepared a vitamin E nanoemulsion that was added to RBC units and stored at 4 °C. Controls, without vitamin E, were kept under the same conditions. Reactive oxygen species (ROS) production was monitored for up to 35 days of storage. RBC elasticity was also evaluated using an optical tweezer system. RESULTS: Vitamin E-treated samples presented a significant decrease in ROS production. Additionally, the elastic constant for vitamin E-treated RBCs did not differ from the control. CONCLUSION: Vitamin E decreased the amount of ROS in stored RBCs. Because vitamin E acts on lipid oxidation, results suggest that protein oxidation should also be considered a key factor for erythrocyte elastic properties. Thus, further studies combining vitamin E with protein antioxidants deserve attention, aiming to better preserve overall stored RBC properties.

Determination of VO2-Intensity Relationship and MAOD in Tethered Swimming.

This study aimed to test the reproducibility of the maximal accumulated oxygen deficit (MAOD) values and VO2-intensity relationship parameters as measured during tethered swimming. 9 swimmers performed an incremental test to determine the maximal aerobic force (MAF), 6 submaximal efforts to develop VO2-intensity relationship, and an exhaustive effort to determine MAOD. The tests were performed twice. The reproducibility of the measurements was tested using intraclass correlation (ICC), typical error (TE) and coefficient of variation (CV). High levels of reproducibility were observed for MAF (TE=2.6 N; CV=4.3%; ICC=0.98) and VO2-intensity relationship parameters, as intercept (TE=0.01 L.min(-1); CV=11.4%; ICC=0.97), slope (TE=0.002 L.min(-1).N(-1); CV=3.1%; ICC=0.97) and coefficient of determination (TE=0.02; CV=1.8%; ICC=0.47). The MAOD values measured during the test (2.9±1.1 L and 45.3±14.0 mL.Kg(-1)) and retests (2.9±1.1 L and 45.2±12.6 mL.Kg(-1)) were highly correlated (absolute values: ICC=0.93; relative to body mass values: ICC=0.89) and presented low values of TE (0.3 L and 4.3 mL.Kg(-1)) and CV (9.5% for absolute and 9.6% for relative to body mass values). Thus, we demonstrated the potential use of tethered swimming to assess anaerobic capacity in an aquatic environment.

Effects of acute aerobic exercise on leukocyte inflammatory gene expression in systemic lupus erythematosus.

UNLABELLED: Systemic lupus erythematosus (SLE) is an autoimmune disease with a persistent systemic inflammation. Exercise induced inflammatory response in SLE remains to be fully elucidated. The aim of this study was to assess the effects of acuteexercise on leukocyte gene expression in active (SLEACTIVE) and inactive SLE (SLEINACTIVE) patients and healthy controls(HC). METHODS: All subjects (n = 4 per group) performed a 30-min single bout of acute aerobic exercise (~70% of VO2peak) on a treadmill, and blood samples were collected for RNA extraction from circulating leukocyte at baseline, at the end of exercise, and after three hours of recovery. The expression of a panel of immune-related genes was evaluated by a quantitative PCR array assay. Moreover, network-based analyses were performed to interpret transcriptional changes occurring after the exercise challenge. RESULTS: In all groups, a single bout of acute exercise led to the down-regulation of the gene expression of innate and adaptive immunity at the end of exercise (e.g., TLR3, IFNG, GATA3, FOXP3, STAT4) with a subsequent up-regulation occurring upon recovery. Exercise regulated the expression of inflammatory genes in the blood leukocytes of the SLE patients and HC, although the SLE groups exhibited fewer modulated genes and less densely connected networks (number of nodes: 29, 40 and 58; number of edges: 29, 60 and 195; network density: 0.07, 0.08 and 0.12, for SLEACTIVE, SLEINACTIVE and HC, respectively). CONCLUSION: The leukocytes from the SLE patients, irrespective of disease activity, showed a down-regulated inflammatory geneexpression immediately after acute aerobic exercise, followed by an up-regulation at recovery. Furthermore, less organized gene networks were observed in the SLE patients, suggesting that they may be deficient in triggering a normal exercised-induced immune transcriptional response.

Running-based Anaerobic Sprint Test as a Procedure to Evaluate Anaerobic Power.

The aim of this study was to evaluate the use of the running anaerobic sprint test (RAST) as a predictor of anaerobic capacity, compare it to the maximal accumulated oxygen deficit (MAOD) and to compare the RAST's parameters with the parameters of 30-s all-out tethered running on a treadmill. 39 (17.0±1.4 years) soccer players participated in this study. The participants underwent an incremental test, 10 submaximal efforts [50-95% of velocity correspondent to VO(2MAX) (vVO(2MAX))] and one supramaximal effort at 110% of vVO(2MAX) for the determination of MAOD. Furthermore, the athletes performed the RAST. In the second stage the 30-s all-out tethered running was performed on a treadmill (30-s all-out), and compared with RAST. No significant correlation was observed between MAOD and RAST parameters. However, significant correlations were found between the power of the fifth effort (P5) of RAST with peak and mean power of 30-s all-out (r=0.73 and 0.50; p<0.05, respectively). In conclusion, the parameters from RAST do not have an association with MAOD, suggesting that this method should not be used to evaluate anaerobic capacity. Although the correlations between RAST parameters with 30-s all-out do reinforce the RAST as an evaluation method of anaerobic metabolism, such as anaerobic power.

Glicerina bruta associada à silagem de sorgo em dietas para cordeiros / Crude gliceryn associated with sorghum silagein diets for lambs

Objetivou-se avaliar os níveis de glicerina bruta (GB), 0, 20, 40, 60 e 80g/kg de matéria seca (MS) de silagem de sorgo sobre a cinética da fermentação, 0, 30, 60 e 90g/kg de MS de silagem sobre a cinética de degradação da fibra em detergente neutro (FDN), e os níveis 0, 17, 33, 55 e 70g/kg de MS de silagem sobre o consumo e a digestibilidade da MS, os compostos nutricionais e o balanço de nitrogênio em cordeiros. O volume e a taxa de degradação dos carboidratos não fibrosos (Vcnf) e (Kdcnf), respectivamente, apresentaram comportamento quadrático, sendo estimado Vcnf máximo (126,62mL/g de MS) e Kdcnf mínima (0,0782/h) para inclusão de 54,85g e 58,75g GB/kg de MS, respectivamente. Já o tempo de colonização (L), apresentou um decréscimo linear de 0,013h para cada 10g de GB/kg de MS. Houve redução linear de 0,996% na degradação para fração B. Não houve efeito significativo da inclusão de GB sobre o consumo e a digestibilidade da MS, os compostos nutricionais e o balanço de nitrogênio. A utilização de GB entre 50 e 70g/kg de MS em dietas à base de silagem de sorgo pode ser fonte alternativa de energia para cordeiros.(AU)

This study aimed to assess the levels of crude glycerin (CG) 0, 20, 40, 60 and 80g/kg of dry matter (DM) of sorghum silage on fermentation kinetics, 0, 30, 60 and 90g/kg DM silage on the kinetics of degradation of neutral detergent fiber (NDF), and levels 0, 17, 33, 55 and 70g/kg DM silage on intake and digestibility of DM and nutritional compounds and nitrogen balance in lambs. The volume and rate of digestion of non-fiber carbohydrates (Vcnf) and (Kdcnf), respectively, showed a quadratic Vcnf being estimated maximum (126.62mL/g DM) and Kdcnf minimum (0.0782/h) for inclusion of 54.85 CG 58.75g/kg DM, respectively. Since the time of colonization (L), they presented a linear decrease of 0.013h for each 10g CG/kg. DM linearly decreased from 0.996% degradation for fraction B. There was no significant effect of the inclusion of CG on the intake and dry matter digestibility and nutritional compounds and nitrogen balance. The use of 50CG to 70g/kg DM in diets based on sorghum silage can be an alternative energy source for sheep.(AU)

Relationship of aerobic and anaerobic parameters with 400 m front crawl swimming performance.

The aims of the present study were to investigate the relationship of aerobic and anaerobic parameters with 400 m performance, and establish which variable better explains long distance performance in swimming. Twenty-two swimmers (19.1±1.5 years, height 173.9±10.0 cm, body mass 71.2±10.2 kg; 76.6±5.3% of 400 m world record) underwent a lactate minimum test to determine lactate minimum speed (LMS) (i.e., aerobic capacity index). Moreover, the swimmers performed a 400 m maximal effort to determine mean speed (S400m), peak oxygen uptake ([Formula: see text]) and total anaerobic contribution (CANA). The CANA was assumed as the sum of alactic and lactic contributions. Physiological parameters of 400 m were determined using the backward extrapolation technique ([Formula: see text] and alactic contributions of CANA) and blood lactate concentration analysis (lactic anaerobic contributions of CANA). The Pearson correlation test and backward multiple regression analysis were used to verify the possible correlations between the physiological indices (predictor factors) and S400m (independent variable) (p < 0.05). Values are presented as mean ± standard deviation. Significant correlations were observed between S400m (1.4±0.1 m·s-1) and LMS (1.3±0.1 m·s-1; r = 0.80), [Formula: see text] (4.5±3.9 L·min-1; r = 0.72) and CANA (4.7±1.5 L·O2; r= 0.44). The best model constructed using multiple regression analysis demonstrated that LMS and [Formula: see text] explained 85% of the 400 m performance variance. When backward multiple regression analysis was performed, CANA lost significance. Thus, the results demonstrated that both aerobic parameters (capacity and power) can be used to predict 400 m swimming performance.

Mesenchymal stem cells from umbilical cord blood: parameters for isolation, characterization and adipogenic differentiation.

Isolation of mesenchymal stem cells (MSCs) from umbilical cord blood (UCB) from full-term deliveries is a laborious, time-consuming process that results in a low yield of cells. In this study we identified parameters that can be helpful for a successful isolation of UCB-MSCs. According to our findings, chances for a well succeeded isolation of these cells are higher when MSCs were isolated from UCB collected from normal full-term pregnancies that did not last over 37 weeks. Besides the duration of pregnancy, blood volume and storage period of the UCB should also be considered for a successful isolation of these cells. Here, we found that the ideal blood volume collected should be above 80 mL and the period of storage should not exceed 6 h. We characterized UCB-MSCs by morphologic, immunophenotypic, protein/gene expression and by adipogenic differentiation potential. Isolated UCB-MSCs showed fibroblast-like morphology and the capacity of differentiating into adipocyte-like cells. Looking for markers of the undifferentiated status of UCB-MSCs, we analyzed the UCB-MSCs' protein expression profile along different time periods of the differentiation process into adipocyte-like cells. Our results showed that there is a decrease in the expression of the markers CD73, CD90, and CD105 that correlates to the degree of differentiation of UCB-MSCs We suggest that CD90 can be used as a mark to follow the differentiation commitment degree of MSCs. Microarray results showed an up-regulation of genes related to the adipogenesis process and to redox metabolism in the adipocyte-like differentiated MSCs. Our study provides information on a group of parameters that may help with successful isolation and consequently with characterization of the differentiated/undifferentiated status of UCB-MSCs, which will be useful to monitor the differentiation commitment of UCB-MSC and further facilitate the application of those cells in stem-cell therapy.

Characterization of bovine transcripts preferentially expressed in testis and with a putative role in spermatogenesis.

Although the number of genes known to be associated with bovine spermatogenesis has increased in the past few years, regulation of this biological process remains poorly understood. Therefore, discovery of new male fertility genetic markers is of great value for assisted selection in commercially important cattle breeds, e.g., Nelore, that have delayed reproductive maturation and low fertility rates. The objective of the present study was to identify sequences associated with spermatogenesis that could be used as fertility markers. With RT-PCR, the following five transcripts preferentially expressed in adult testis were detected: TET(656) detected only in adult testis; TET(868) and TET(515) expressed preferentially in adult testis but also detected in fetal gonads of both sexes; and TET(456) and TET(262,) expressed primarily in the testis, but also present in very low amounts in somatic tissues. Based on their homologies and expression profiles, we inferred that they had putative roles in spermatogenesis. Detection of sequences differentially expressed in testis, ovary, or both, was a useful approach for identifying new genes related to bovine spermatogenesis. The data reported here contributed to discovery of gene pathways involved in bovine spermatogenesis, with potential for prediction of fertility.

Validação comparativa utilizando PCR quantitativo em tempo real (qPCR) e PCR convencional de sêmen bovino centrifugado em gradiente de densidade contínuo / Comparative validation using quantitative real-time PCR (qPCR) and conventional PCR of bovine semen centrifuged in continuous density gradient

The objective of the present study was to determine the sperm enrichment with X-bearing spermatozoa, after one centrifugation in a Percoll or OptiPrep continuous density gradient, using quantitative real-time polymerase chain reaction (qPCR) of sperm DNA and resultant in vitro-produced bovine embryos by PCR. Frozen/thawed sperm was layered on density gradients and the tubes were centrifuged. Supernatants were gently aspirated and the sperm recovered from the bottom of the tubes. Cleavage and blastocyst rates were determined through in vitro production of embryos and PCR was performed to identify the embryos' genetic sex. A difference in blastocyst rate was found in the Percoll treatment compared to OptiPrep (P<0.05). The percentage of female embryos in the Percoll and OptiPrep groups was 62.0 percent and 47.1 percent, respectively. These results were confirmed by qPCR of spermatozoa DNA and underestimation was seen only in the Percoll group. It was possible to sexing sperm using simple approach.

O objetivo do presente estudo foi determinar o enriquecimento de espermatozoides portadores do cromossomo X após a centrifugação em gradiente de densidade contínuo de Percoll ou OptiPrep, utilizando reação em cadeia da polimerase quantitativa em tempo real (qPCR) do DNA do espermatozoide e dos embriões bovinos produzidos in vitro resultantes pela PCR convencional. Espermatozoides descongelado foram depositados em gradientes de densidade e os tubos foram centrifugados. Os sobrenadantes foram gentilmente aspirados e os espermatozoides recuperados do fundo dos tubos. As taxas de clivagem e de blastocisto foram determinadas pela produção in vitro de embriões e a PCR foi realizada para a identificação genética do sexo dos embriões. Verificou-se diferença na taxa de blastocistos entre os grupos Percoll e OptiPrep (P<0,05). A porcentagem de embriões de fêmeas nos grupos Percoll e OptiPrep foi de 62,0 por cento e 47,1 por cento, respectivamente. Estes resultados foram confirmados pela qPCR do DNA de espermatozoides e uma subestimação foi observada no grupo do gradiente de densidade de Percoll. Foi possível a sexagem de espermatozoides utilizando uma metodologia simples.

Development of Y-chromosome-specific SCAR markers conserved in taurine, zebu and bubaline cattle.

Sex pre-selection of bovine offsprings has commercial relevance for cattle breeders and several methods have been used for embryo sex determination. Polymerase chain reaction (PCR) has proven to be a reliable procedure for accomplishing embryo sexing. To date, most of the PCR-specific primers are derived from the few single-copy Y-chromosome-specific gene sequences already identified in bovines. Their detection demands higher amounts of embryonic genomic material or a nested amplification reaction. In order to circumvent this, limitation we searched for new male-specific sequences potentially useful in embryo sexing using random amplified polymorphic DNA (RAPD) analysis. Random amplified polymorphic DNA (RAPD) assay reproducibility problems can be overcome by its conversion into Sequence Characterized Amplified Region (SCAR) markers. In this work, we describe the identification of two bovine male-specific markers (OPC16(323) and OPF10(1168)) by means of RAPD. These markers were successfully converted into SCARs (OPC16(726) and OPF10(984)) using two pairs of specific primers.Furthermore, inverse PCR (iPCR) methodology was successfully applied to elongate OPC16(323) marker in 159% (from 323 to 837 bp). Both markers are shown to be highly conserved (similarity ≥95%) among bovine zebu and taurine cattle; OPC16(323) is also highly similar to a bubaline Y-chromosome-specific sequence. The primers derived from the two Y-chromosome-specific conserved sequences described in this article showed 100% accuracy when used for identifying male and female bovine genomic DNA, thereby proving their potential usefulness for bovine embryo sexing.

210Pb in forage consumed by dairy cows.

The aim of this research was to determine (210)Pb concentrations in forage from farms located in the municipalities of Pedra and Venturosa, in the Brazilian state of Pernambuco, where rolled blocks of mafic rock with a high percentage of U(3)O(8) were found. The concentrations of (210)Pb varied from 2 to 503 Bq kg(-1) in the forage dry matter samples evaluated. Due to the elevated levels of (210)Pb in the forage samples, it is concluded that this radionuclide is highly available to be ingested by dairy cows and this could represent a hazard to the human population due to possible milk contamination.