Deforestation and fragmentation trends of seasonal dry tropical forest in Ecuador: impact on conservation

Background:Fragmentation and deforestation are one of the greatest threats to forests,and these processes are of even more concern in the tropics,where the seasonal dry forest is possibly one of the most threatened ecosystems with the least remaining surface area.Methods:The deforestation and fragmentation patterns that had occurred in Ecuadorian seasonal dry forests between 1990 and 2018 were verified,while geographic information systems and land cover shapes provided by the Ecuadorian Ministry of the Environment were employed to classify and evaluate three types of seasonal dry forests:deciduous,semi-deciduous,and transition.The study area was tessellated into 10 km2 hexagons,in which six fragmentation parameters were measured:number of patches,mean patch size,median patch size,total edge,edge density and reticular fragmentation index(RFI).The RFI was also measured both outside and inside protected natural areas(unprotected,national protected areas and protected forest).Moreover,the areas with the best and worst conservation status,connectivity and risk of disappearance values were identified by means of a Getis-Ord Gi*statistical analysis.Results:The deforestation of seasonal dry forests affected 27.04%of the original surface area still remaining in 1990,with an annual deforestation rate of−1.12%between 1990 and 2018.The RFI has increased by 11.61%as a result of the fact that small fragments of forest have tended to disappear,while the large fragments have been fragmented into smaller ones.The semi-deciduous forest had the highest levels of fragmentation in 2018.The three categories of protection had significantly different levels of fragmentation,with lower RFI values in national protected areas and greater values in protected forests.Conclusions:The seasonal dry forest is fragmenting,deforesting and disappearing in some areas.An increased protection and conservation of the Ecuadorian seasonal dry forest is,therefore,necessary owing to the fact that not all protection measures have been effective.

Extracellular vesicles from oviductal and uterine fluids supplementation in sequential in vitro culture improves bovine embryo quality

Background:In vitro production of bovine embryos is a well-established technology,but the in vitro culture(IVC)system still warrants improvements,especially regarding embryo quality.This study aimed to evaluate the effect of extracellular vesicles(EVs)isolated from oviductal(OF)and uterine fluid(UF)in sequential IVC on the development and quality of bovine embryos.Zygotes were cultured in SOF supplemented with either BSA or EVs-depleted fetal calf serum(dFCS)in the presence(BSA-EV and dFCS-EV)or absence of EVs from OF(D1 to D4)and UF(D5 to D8),mimicking in vivo conditions.EVs from oviducts(early luteal phase)and uterine horns(mid-luteal phase)from slaughtered heifers were isolated by size exclusion chromatography.Blastocyst rate was recorded on days 7-8 and their quality was assessed based on lipid contents,mitochondrial activity and total cell numbers,as well as survival rate after vitrification.Relative mRNA abundance for lipid metabolism-related transcripts and levels of phosphorylated hormonesensitive lipase(pHSL)proteins were also determined.Additionally,the expression levels of 383 miRNA in OF-and UF-EVs were assessed by qRT-PCR.Results:Blastocyst yield was lower(P<0.05)in BSA treatments compared with dFCS treatments.Survival rates after vitrification/warming were improved in dFCS-EVs(P<0.05).EVs increased(P<0.05)blastocysts total cell number in dFCS-EV and BSA-EV compared with respective controls(dFCS and BSA),while lipid content was decreased in dFCSEV(P<0.05)and mitochondrial activity did not change(P>0.05).Lipid metabolism transcripts were affected by EVs and showed interaction with type of protein source in medium(PPARGC1B,LDLR,CD36,FASN and PNPLA2,P<0.05).Levels of pHSL were lower in dFCS(P<0.05).Twenty miRNA were differentially expressed between OF-and UF-EVs and only bta-miR-148b was increased in OF-EVs(P<0.05).Conclusions:Mimicking physiological conditions using EVs from OF and UF in sequential IVC does not affect embryo development but improves blastocyst quality regarding survival rate after vitrification/warming,total cell number,lipid content,and relative changes in expression of lipid metabolism transcripts and lipase activation.Finally,EVs miRNA contents may contribute to the observed effects.

Circulating leptin and its muscle gene expression in Nellore cattle with divergent feed efficiency

Background： Leptin has a strong relation to important traits in animal production, such as carcass composition,feed intake, and reproduction. It is mainly produced by adipose cells and acts predominantly in the hypothalamus.In this study, circulating leptin and its gene expression in muscle were evaluated in two groups of young Nellore bulls with divergent feed efficiency. Individual dry matter intake（DMI） and average daily gain（ADG） of 98 Nellore bulls were evaluated in feedlot for 70 d to determinate the residual feed intake（RFI） and select 20 animals for the high feed efficient（LRFI） and 20 for the low feed efficient（HRFI） groups. Blood samples were collected on d 56 and at slaughter（80 d） to determine circulating plasma leptin. Samples of Longissimus dorsi were taken at slaughter for leptin gene expression levels.Results： DMI and RFI were different between groups and LRFI animals showed less back fat and rump fat thickness,as well as less pelvic and kidney fat weight. Circulating leptin increased over time in all animals. Plasma leptin was greater in LRFI on 56 d and at slaughter（P = 0.0049）. Gene expression of leptin were greater in LRFI animals（P = 0.0022） in accordance with the plasma levels. The animals of the LRFI group were leaner, ate less, and had more circulating leptin and its gene expression.Conclusion： These findings demonstrated that leptin plays its physiological role in young Nellore bulls, probably controlling food intake because feed efficient animals have more leptin and lower residual feed intake.

Brazilian vaccinia virus strains show a classical orthopoxvirus infection course and cross-protection

【正】Objectives:The purpose of this work was to study the infection course and cross-protection in mice after intradermal injection of Vaccinia virus(VACV) strain Western Reserve and three Brazilian VACV strains: Aracatuba,Muriae and BeAn58058 isolated from cow,human and rodent,respectively.Methods:Balb/c mice were inoculated by footpad and back scarification and daily monitored regarding lesion development and weight loss.To check cross protection after intradermal VACV inoculation,mice were subsequendy infected with different VACV strains and monitored to check lesion development.Serum neutralization assays were performed to check for the presence of antibodies against Orthopoxvirus.Results:After VACV intradermal inoculation the lesion development pattern was similar in mice infected with the different virus strains.By using the footpad scarification model,cross-protection among VACV strains was observed.Moreover,neutralizing antibodies against Orthopoxvirus were detected in sera from mice infected with all VACV strains.Conclusion:Although it was not possible to observe virulence differences among VACV strains isolated from cow,rodent and human using the murine model,this inoculation route showed to be an appropriated model to study lesions development since it mimics natural infections by VACV in nature.

Effect of Citric Acid, Phytase and Calcium Levels on the Calcium and Phosphorus Content in Egg: Yolk-Albumen and Shell, Yolk Color and Egg Quality in Diets of Laying Hens

To evaluate the effect of different levels of citric acid (CA) combined with phytase and calcium levels in the diets of laying hens on the calcium and phosphorus (P) contents of eggs: yolk-albumen and shell, yolk color and egg quality. A study was conducted with 24-week-old laying hens fed with a diet based on sorghum and soybean meal with 2.7 Mcal of EM/kg, 15% crude protein, 3.25% calcium and 0.25% available P. The levels of CA, phytase and calcium were 0%, 0.6% and 1.2%;0 and 300 units of phytase (PHYU)/kg;and 3.0% and 3.25%, respectively. Phytase was added as an ingredient into to the diets, contributing 0.1% P and 0.3% calcium. A completely randomized factorial experiment was performed with a 3 × 2 × 2 design and 4 replications. The CA increased (P < 0.05) the P in the shell, and the combination of 1.2% CA, 300 PHYU phytase and 3.25% calcium increased (P < 0.05) the calcium in the eggshell. There was a CA × phytase × calcium interaction (P < 0.05) affecting egg yolk pigmentation;there were no differences in egg quality. It was concluded that adding CA to the diets of laying hens increases eggshell calcium content, and improves the phytase response. 1.2% CA × Phytase × 3.25% calcium significantly increases shell calcium by 0.56 g. Under the conditions of the present investigation, it would imply greater resistance of the eggs to be broken in the handling from the farm to the sales centers and consumer. Phytase interacts negatively with 0.6% CA at low calcium levels to degrade the yellow pigmentation of the yolk.

Diurnal Rhythm of Antioxidant Biomarkers in Equines

The aim of the present study was to test the hypothesis that glutathione peroxidase, uric acid, and a number of hematological biomarkers do not vary in adult mares, over a 24-hour period. Seven adult (age 10 ± 6 yrs;weight 370 ± 30 kg) Arabian Purebred mares were used. Blood samples were collected every two hours, except during the period after-meals, when samples were collected every 30 minutes, totaling four samples in two hours. These samples were used to analyze glutathione peroxidase (GPx), uric acid (UA), glucose (GLU), total plasma protein (TPP), red blood cells (RBC), hemoglobin (HB), hematocrit (HT), red cell distribution width (RDW), white blood cells (WBC) and lymphocytes (LYM). One-way repeated measures analysis of variance (ANOVA) was used to determine significant differences. Tukey’s test was used for multiple comparisons between the averages. Ρ

The Role of CD4+ and CD8+ T-Cells during Angiostrongylus vasorum Infection in Dogs

A determinant factor in the pathology of canine angiostrongylosis seems to be related to the location of the parasite in the definitive host. Their presence inside the arteries and its branches, promoting mechanical and metabolic action on the wall of the vessels, may alter its homeostasis. Bronchoalveolar lavage (BAL) is a procedure that retrieves cells and other elements from de lungs for evaluation, and helps in the diagnosis of many pulmonary diseases. The aim of this study was to evaluate CD4+/CD8+ lymphocyte profile during the infection by Angiostrongylus vasorum, using cells retrieved using BAL. The identification of subpopulations of T lymphocytes by evaluating the co-expression of CD4 and CD8 receptor proteins has shown that despite the increase in both populations, there was a predominance of CD4+ T-cells, instead of CD8+ T-cells. These increases of CD4+ T-cells associated with the increase of the ratio between CD4+/CD8+ suggest polarization of a Th2 response. However, the immune cells, signaling factors, and cytokines that mediate such immunity and how and where they act within the body remain largely undefined during angiostrongylosis.