Evaluation of the Influence of Natural and Antrhopogenic Processes on Water Quality in Karstic Region

This paper presents a comprehensive study on the quality of surface and groundwater in an environmentally sensitive karstic watershed strongly pressed by urban growth. The objective of the study was to assess the integrated effects of human activities and natural characteristics of karstic environments on the quality of surface and groundwater using multivariate statistical techniques. Data from 18 physical, chemical, and microbiological water quality variables obtained throughout a hydrological year were analyzed using principal components analysis (PCA) and cluster analysis. The PCA was carried out individually for surface water and groundwater. Our goal was to study the behavior of the water quality variables at each of these systems, as well as to infer the importance of these variables on the dynamics of the water resources in the region. Our results for surface water showed that the 18 original variables could be reduced to five principal components which together accounted for 69% of the total variation in the data, whereas for groundwater, 70% of the total variation in the data was explained by five principal components. In order to evaluate the impacts of anthropic activities on the water quality at the monitoring locations, the cluster analysis was applied to the ten sampling points. The analysis identified five clusters, two of which are formed by points with low contamination levels and three where the anthropic interference is noticeable. The results suggest the existence of specific contamination sources in many points, including in the groundwater, and highlight the natural vulnerability of the karstic environments.     

Effect of Sperm Cryopreservation on the European Eel Sperm Viability and Spermatozoa Morphology

The main objective of the present work was to study the effect of cryopreservation of European eel sperm both on the sperm viability and the spermatozoa head morphology. Spermatozoa morphology was evaluated with computer-assisted morphology analysis after collection in fresh samples, after adding the freezing medium containing dimethyl sulfoxide as cryoprotectant and, finally, after the cryopreservation process and thawing. Cell viability was assessed, in both fresh and thawed samples, by Hoechst 33258 staining. Computer-assisted sperm analysis (CASA) was used to determine the percentage of motile cells and to measure motility parameters in sperm samples. A significant decrease of head perimeter (12.56%) and area (17.90%) was detected from spermatozoa in fresh to thawed samples, indicating that cells do not recover the original size after the cryopreservation process. CASA was used to measure the percentage of motile cells (51.9%) and spermatozoa motility parameters such as curvilinear, straight line and angular path velocities, as well as beating cross frequency. This technique was employed in the fresh sperm samples but proteins present at the freezing medium (L-alpha-phosphatidylcholine) made impossible to use this last technique in thawed samples. When sperm viability was assessed by Hoechst staining, a significant decrease of approximately 15% (73.10 vs 58.26%) of alive spermatozoa was registered from fresh to thawed samples. The percentage of motile cells measured by CASA in fresh samples (51.9%) was lower than the percentage of alive cells determined by Hoechst stainning, suggesting the existence of different batches of spermatozoa in different stages of development, even during the eight to tenth weeks of treatment, when the highest sperm quality was found.     

谷子新品种朝谷11号特征特性及高产栽培技术

朝谷 1 1号由辽宁省水土保持研究所选育 ,于1 997年经辽宁省品种审定委员会审定通过。1 998年被列为省重点农技推广项目 ,计划在 1 998～ 2 0 0 0年在辽宁省朝阳市、阜新市、葫芦岛市的 8县 2区及赤峰市的宁城县推广 6.7万ｈｍ2 。1　朝谷 11号主要特征特性1 .1　农艺性状朝谷 1 1号的叶片、成株茎均为绿色 ,苗期生长快 ,株型紧凑整齐 ,株高 1 65ｃｍ左右 ,穗长 2 3～ 2 5ｃｍ ,单穗粒重 1 4～ 1 6ｇ ,籽粒圆形、黄色 ,出谷率 83%～ 84%,谷草比 1∶1 .3。1 .2　生育期及抗性朝谷 1 1号为中早熟品种 ,生育期 1 0 4～ 1 1 4ｄ ,4月下旬至 5月…     

Wilt and die‐back of Eucalyptus spp. caused by Erwinia psidii in Brazil

A new disease of unknown bacterial aetiology has been observed in eucalyptus stands since 2009. It is characterized by die‐back, wilting and lesions on the branches, petiole and midrib in association with macroscopic and microscopic bacterial ooze. To date, this disease has been observed in stands of clonal Eucalyptus saligna, E. grandis and E. urophylla x E. grandis hybrids and in E. dunnii seedling plantations in the states of São Paulo, Rio Grande do Sul and Mato Grosso do Sul. Considering the economic importance of eucalyptus plantations and the potential losses caused by this disease, this study aimed to identify and characterize the causal agent. Thirty‐four strains were obtained from infected plants, which were collected in the field from four locations. The inoculation of detached leaves and intact rooted cuttings supported pathogenicity in eucalyptus. The phylogenetic analysis of four housekeeping genes (16S rDNA, gapA, recA and rpoB) as well as biochemical tests confirmed the identity of strains belonging to the species Erwinia psidii. This is the first report of E. psidii as the cause of wilt and die‐back in Eucalyptus spp. in Brazil.     

Is the Santa Inês sheep a typical non-seasonal breeder in the Brazilian Southeast?

This study aimed to characterize the annual reproductive cycle of Santa Inês sheep in the Fluminense lowland region (latitude 22° 27′ 45″ south, Rio de Janeiro, Brazil) between September 2011 and August 2012. Ten ewes were maintained in a semi-intensive system under natural photoperiods with access to pasture and shelter. Blood samples were collected every 2 weeks to determine plasma progesterone concentrations. The body condition score (BCS) was determined each month. There was no seasonal variation in the plasma progesterone concentration from the months of September to January, April, and May to August. In the months of February and April, the plasma hormone levels were higher than August to November. Seventy percent (7/10) of the sheep studied had short seasonal anestrus. The periods of anestrus were concentrated between the months of September and December (spring season) in 85.7 % (6/7) of the cases evaluated. In these cases, 57.1 % (4/7) also had short periods of reproductive inactivity during other months of the year. The progesterone values obtained in the spring corroborate the higher reproductive anestrus observed in this season. Higher plasma progesterone values were found in summer and autumn with reduction in the winter to lower values in the spring. No changes in the BCS during the study period were observed. Under the studied conditions, the Santa Inês sheep showed a low degree of reproductive seasonality. However, some individual ewes had seasonal anestrus during the spring. Further studies that include management techniques are needed to improve reproductive efficiency without hormone therapy in this breed under tropical conditions.     

Genetic parameter estimation for pre- and post-weaning traits in Brahman cattle in Brazil

Beef cattle producers in Brazil use body weight traits as breeding program selection criteria due to their great economic importance. The objectives of this study were to evaluate different animal models, estimate genetic parameters, and define the most fitting model for Brahman cattle body weight standardized at 120 (BW120), 210 (BW210), 365 (BW365), 450 (BW450), and 550 (BW550) days of age. To estimate genetic parameters, single-, two-, and multi-trait analyses were performed using the animal model. The likelihood ratio test was verified between all models. For BW120 and BW210, additive direct genetic, maternal genetic, maternal permanent environment, and residual effects were considered, while for BW365 and BW450, additive direct genetic, maternal genetic, and residual effects were considered. Finally, for BW550, additive direct genetic and residual effects were considered. Estimates of direct heritability for BW120 were similar in all analyses; however, for the other traits, multi-trait analysis resulted in higher estimates. The maternal heritability and proportion of maternal permanent environmental variance to total variance were minimal in multi-trait analyses. Genetic, environmental, and phenotypic correlations were of high magnitude between all traits. Multi-trait analyses would aid in the parameter estimation for body weight at older ages because they are usually affected by a lower number of animals with phenotypic information due to culling and mortality.     

Supplementation of suckling beef calves with different levels of crude protein on tropical pasture

The effects of supplementation with different levels of crude protein on performance, intake and nutrient digestibility and efficiency of microbial protein synthesis in suckling beef calves on pasture were assessed. Fifty-five calves, with an average age of 100 days and an initial average body weight of 110?±?7.5 kg and their respective dams, were used. The experimental design was completely randomised with five treatments and 11 replications. The experimental treatments for calves were as follows: control = calves received only mineral mixture; supplementation levels = calves received supplement containing 8, 19, 30 or 41 % of crude protein (CP, at a rate of 0.5 % of body weight (BW)). The cows received only mineral mixture ad libitum. Supplemented calves had higher (P?<?0.1) average daily gain (ADG). Protein levels showed a quadratic effect (P?<?0.1) on average daily gain (ADG) of calves. There was no difference in total dry matter (DM) intake (P?>?0.1). However, intake of dry matter forage (DMF) presented cubic profiles (P?<?0.1), with CP levels in the supplements. Supplementation increased (P?<?0.1) the digestibility of nutrients, except for the digestibility of neutral detergent fibre. Supplementation increased (P?<?0.1) the production of microbial nitrogen and N losses in urine. It can be concluded that multiple supplementations optimise the performance of beef calves on creep feeding. The intake of supplements with CP levels between 8 and 30 % partially replaces of the pasture ingested by calves and increases the digestibility of the diet.     

Tuberculosis prevalence and risk factors for water buffalo in Pará, Brazil

The prevalence of and possible risk factors for tuberculosis were studied in water buffalo from Pará, Brazil. In this study, 3,917 pregnant and nonpregnant female Murrah and Mediterranean buffaloes were studied; 2,089 originated from Marajó Island, and 1,108 were from the mainland. The comparative cervical tuberculin test was used as a diagnostic test for tuberculosis in these animals. The prevalence of positive buffaloes was 3.5 % (100/2,809) on Marajó Island and 7.2 % (80/1,108) on the mainland. The municipalities with the highest tuberculosis prevalence rates in animals were Ipixuna do Pará (10.1 %), Marapanim (9.8 %), Chaves (9.4 %), Paragominas (8.6 %), and Cachoeira do Arari (6.7 %). The tuberculosis prevalence was not significantly different between the Murrah (4.3 %) and Mediterranean (4.8 %) breeds or between pregnant (5 %) and nonpregnant (4.3 %) buffaloes. Tuberculosis was detected in water buffaloes from Pará, Brazil; the mainland buffalo exhibited the highest tuberculosis prevalence. These results indicate that this disease is dangerous to public health and buffalo farming in Pará.     

NEAR's flyby of 253 mathilde: images of a C asteroid

On 27 June 1997, the Near Earth Asteroid Rendezvous (NEAR) spacecraft flew within 1212 kilometers of asteroid 253 Mathilde. Mathilde is an irregular, heavily cratered body measuring 66 kilometers by 48 kilometers by 46 kilometers. The asteroid's surface is dark (estimated albedo between 0.035 and 0.050) and similar in color to some CM carbonaceous chondrites. No albedo or color variations were detected. The volume derived from the images and the mass from Doppler tracking of the spacecraft yield a mean density of 1.3 +/- 0.2 grams per cubic centimeter, about half that of CM chondrites, indicating a porous interior structure.     

Habitat split and the global decline of amphibians

The worldwide decline in amphibians has been attributed to several causes, especially habitat loss and disease. We identified a further factor, namely "habitat split"-defined as human-induced disconnection between habitats used by different life history stages of a species-which forces forest-associated amphibians with aquatic larvae to make risky breeding migrations between suitable aquatic and terrestrial habitats. In the Brazilian Atlantic Forest, we found that habitat split negatively affects the richness of species with aquatic larvae but not the richness of species with terrestrial development (the latter can complete their life cycle inside forest remnants). This mechanism helps to explain why species with aquatic larvae have the highest incidence of population decline. These findings reinforce the need for the conservation and restoration of riparian vegetation.