The effect of ultraviolet rays and climatic conditions (solar radiation and temperature) on the calcinogenic activity of Trisetum flavescens and Nierembergia veitchii]

Cholecalciferol (Vitamin D3) and its metabolites participate in the regulation of Ca and P metabolism in vertebrates. The intermediate (6,7-cis-precalciferol) is formed by a photoreaction at wave length of 250-310 nm from 7-dehydrocholecalciferol in skin tissues. Vitamin D3, 1,25(OH)2 D3 and other metabolites, previously known to be synthesized only in mammalians and avians, have been detected also in plants. The influence of the UV light (6 hrs radiation with 254 nm) in the calcinogenic activity of T. flavescens and N. veitchii was tested. The extracts of the plants were administered to rachitic chicks in two research models: "Alimentation without Vitamin D" and "Strontium added Alimentation". After 25 days the extracts were administered (per os) and the serum was analyzed to determine the level of Ca, P and alkaline phosphatase. The results were compared with those obtained in chicks with standards of vitamin D3, 1,25(OH)2 D3, T. flavescens and N. veitchii not irradiated and also with T. flavescens that has grown in Rio Grande do Sul/Brazil.     

Growth of <Emphasis Type="Italic">Euterpe edulis</Emphasis> Mart. (Arecaceae) under forest and agroforestry in southern Brazil

The palm Euterpe edulis has high ecological and economic importance in Brazil. Currently, this species is being cultivated and managed for spontaneous regeneration in banana plantations. However, there are no data comparing its plantation growth performance to its native forest growth. We evaluated growth and mortality (M) of individuals of E. edulis planted in secondary dense ombrophilous forest and in banana plantations, as well as their relationships with site variables (canopy opening, soil nutrient availability, density of existing E. edulis, and herbivory). Twelve banana plantation sites and 12 sites in secondary dense ombrophilous forests were selected. At each site, 25 young individuals of E. edulis were planted in 2003. Annually until 2008, morphometric, herbivory, and M of the individuals were evaluated. In 2008, canopy and soil variables were measured at each plot. E. edulis growth was five times higher in banana plots compared to forest plots; current annual increment on height reached 38.9 cm in banana plots, compared to 7.3 cm in forest plots. M was relatively low and similar at both sites, presenting an intraspecific density-dependence pattern. Significant correlations were found between morphometric variables, M, and herbivory of E. edulis and canopy and soil variables. Euterpe edulis presented plasticity that allows for its establishment in banana plantations, indicating high potential for management in agroforestry consortia. Such management may be a useful conservation strategy for this and other shade-tolerant species.     

Immunohistochemical Detection of Retinoid Receptors in Tumors from 30 Dogs Diagnosed with Cutaneous Lymphoma

Background: Retinoids exert their effects by binding to retinoid receptors. Two types of retinoid receptors have been described: retinoic acid receptor (RAR) and retinoid X receptor (RXR), and their subtypes α, β, and γ. The expression of subtypes varies depending on the disease process. This study intended to detect the pattern of retinoid receptor expression in cutaneous lymphomas in dogs. Hypothesis: Cutaneous lymphomas in dogs have variable expression of retinoid and retinoid X receptors. Animals: Biopsy specimens from 30 dogs with cutaneous lymphoma. Methods: Tissues of dogs with cutaneous lymphoma were evaluated by immunohistochemistry for expression of retinoid receptors. The tissues were tested for the presence of 3 RAR and RXR subtypes (α, β, and γ). Lymphoma immunophenotype was determined by the use of the immunohistochemical markers CD79a (B‐cell) and CD3 (T‐cell) in all cases. Results: Twenty‐nine of 30 dogs were CD3 positive. The retinoid receptors expressed with the greatest frequency were RARβ (87% of cases), and RXRα and RXRγ (77% of cases). The expression of RARγ was not observed. Conclusions and Clinical Relevance: Retinoid and rexinoid receptor binding drugs may have an impact on the treatment of dogs with cutaneous lymphoma.     

Observations anatomiques sur l''épididyme de la sarigue Sud-Americaine (Didelphis azarae)

The epididymides of eight South American Didelphis azarae were examined gross anatomically after in situ preservation with formalin. The shape and division into head, body and tail correspond to those of domestic mammals. The attachment of the vascular portion of the spermatic cord to the middle of the body of the epididymis is similar to conditions in other marsupials. The runica vaginalis parietalis is pigmented as found in other species of didelphis.     

Responsiveness to Progestagen-eCG-Cloprostenol Treatment in Goat Food Restricted for Long Period and Refed

For 6 months, 10 adult Saanen crossbred goats were fed undernutrition diet (70% maintenance), and finally five goats were refed for 6 weeks with 150% maintenance. In all animals oestrus was synchronized using 45 mg FGA vaginal sponge for 11 days, 300 IU eCG and 50 microg cloprostenol 48 h prior to sponge removal. From oestrus onset, during a 24-h period, blood samples were collected for oestradiol and NEFA assay. Ovulation was verified by laparoscopy 3 days after sponge removal. Body mass loss was 18.62 +/- 3.03% of initial weight and in refed goats body weight recovery was 90.63 +/- 3.56%. NEFA level was higher in restricted goats (p < 0.05). Fifty per cent of underfed goats (2/4) and all refed goats (4/4) exhibited oestrus and ovulation. Significant relationship (p < 0.05) was found between weight loss and the interval sponge removal-oestrus onset (r = 0.91) or ovulation rate (r = 0.70). Only in the refed group was the ovulation rate related to the oestradiol amount (r = 0.99) (p < 0.05). Collectively results showed that a short period of improved feeding re-established the responsiveness of oestrus synchronization in chronically fasted goats.     

Río de la Plata voyagers: Deciphering the migration ecology of a vulnerable marine catfish (Genidens barbus) in a large subtropical river (lower Uruguay River)

1. Genidens barbus is a vulnerable marine migrant catfish with low fecundity, a complex life cycle (i.e. mouth breeding), and is the target of industrial and artisanal fisheries of several countries. This species regularly migrates from marine to freshwater environments of the south-western Atlantic.
2. The aim of this work was to delve deeper into the migration ecology of G. barbus, characterizing both its timing and potential environmental drivers. Furthermore, aspects of the population structure and reproduction of migrants in the lower Uruguay River were studied and the presence of juveniles in the adjacent estuarine recruitment area was evaluated.
3. Data from 11 years (2008–2018) of records of adult G. barbus captured by artisanal fisheries were used alongside relevant environmental variables that were recorded monthly. Reproductive biology (i.e. sex ratio, gonadosomatic index, fecundity, and oocyte size) was analysed for a period of 3 years (2016–2018). The juvenile abundance in the Río de la Plata estuary was evaluated seasonally.
4. A total of 935 adult individuals of G. barbus were captured, representing a total biomass of 3,123 kg. The migration timing was from early spring to early summer. The abundance of migrants strongly increased with river discharge, suggesting that this variable regulates the upriver migration. Furthermore, pre- and post-spawn females and males displaying mouth breeding were recorded during the study period, confirming G. barbus reproduction in the lower Uruguay River.
5. The results obtained suggest that G. barbus ascend to spawn in the freshwater environments upstream from the mouth of the Uruguay River. Then, adult males incubate and carry the embryos downstream, releasing juveniles in the Río de la Plata estuary.
6. This relevant information will help with the implementation of effective management polices (e.g. fishing restrictions during the reproductive period) for the presently unregulated fishery of this vulnerable species in the lower Uruguay River.

     

Mesoscale physical processes and the distribution and composition of ichthyoplankton on the southern Brazilian shelf break

The southern Brazilian shelf supports the largest fish stocks in the country, and studies on physical–biological processes in the ecology of ichthyoplankton have been recommended to provide a better understanding of the variability of the recruitment of fishing resources. This study is the first to examine the influence of mesoscale physical processes on the distribution of early life stages of fish in this shelf‐break region. Collections of fish eggs and larvae and measurements of temperature and salinity were made at 13 stations along cross‐shelf transects in December 1997. Myctophidae, Bregmacerotidae, Clupeidae, Synodontidae and Engraulidae were the most abundant larvae in the northern region, while Engraulidae and Bregmacerotidae prevailed further south. In situ hydrographic data, NOAA/AVHRR images and merged TOPEX/POSEIDON + ERS‐1/2 satellite altimetry taken during the cruise revealed an anticyclonic eddy dominating the shelf around 31°S. Larval fish abundance was lower at the centre of this feature, suggesting that the eddy advected poorer offshore waters of tropical origin towards the inner shelf‐concentrating the larvae around the eddy.     

Initial growth and survival of Eucalyptus spp. and Mimosa caesalpiniifolia Benth. in silvopastoral systems and their impact on herbage accumulation of Urochloa decumbens Stapf R. D. Webster

Agroforestry Systems - Silvopastoral systems (SPS) combine tree, herbaceous, and animal components, and may contribute to improve productivity and diversification of activities over time. This...