Estimation of the carbon pool in soil and above-ground biomass within mangrove forests in Southeast Mexico using allometric equations

We report the results of carbon stored in soil and aboveground biomass from the most important area of mangroves in Mexico,with dominant vegetation of Red mangrove(Rhizophora mangle L.),Black mangrove(Avicennia germinans L.),white mangrove(Laguncularia racemosa Gaertn.)and button mangrove(Conocarpus erectus L.).We sampled soils with high fertility during the dry season in 2009 and 2010at three sites on Atasta Peninsula,Campeche.We used allometric equations to estimate above ground biomass(AGB)of trees.AGB was higher in C.erectus(253.18±32.17 t·ha-1),lower in A.germinans(161.93±12.63t·ha-1),and intermediate in R.mangle(181.70±16.58 t·ha-1)and L.racemosa(206.07±19.12 t·ha-1).Of the three studied sites,the highest absolute value for AGB was 279.72 t·ha-1in button mangrove forest at any single site.Carbon stored in soil at the three sites ranged from36.80±10.27 to 235.77±66.11 t·ha-1.The Tukey test(p0.05)made for AGB was higher for black mangrove showed significant differences in soil carbon content between black mangrove and button mangrove.C.erectus had higher AGB compared with the other species.A.germinans trees had lower AGB because they grew in hypersaline environments,which reduced their development.C.erectus grew on higher ground where soils were richer in nutrients.AGB tended to be low in areas near the sea and increased with distance from the coast.A.germinans usually grew on recently deposited sediments.We assumed that all sites have the same potential to store carbon in soil,and then we found that there were no significant differences in carbon content between the three samples sites:all sites had potential to store carbon for long periods.Carbon storage at the three sampling sites in the state of Campeche,Mexico,was higher than that reported for other locations.     

Comparative performance of the red flour beetle Tribolium castaneum (Coleoptera: Tenebrionidae) on different plant diets

Tribolium castaneum is a pest of stored foods that causes serious economic losses. Understanding insect nutritional requirements and the effects of different diets on insect development can provide tools for developing strategies to control insect and integrated pest management systems. In this work we studied the performance of the T. castaneum on different plant diets composed of Vigna unguiculata, Phaseolus vulgaris and wheat flours. The diets interfered differentially with development and insect survival. Larvae size was reduced about 60 % in larvae fed with V. unguiculata flour. A delay in pupae formation was also observed. The larval mortality of 100 % was observed in the P. vulgaris diet. Carbohydrate and triglyceride showed variations during development and with different diets. Larvae fed with wheat diets showed a high concentration of carbohydrates 21 days after hatching (DAH) and triglyceride at 15 and 21 DAH. Larvae fed with wheat diets showed α-amylase activity during development. At 15 DAH the activity of larvae fed with V. unguiculata increased about 50 %. Cysteine protease activity in larvae fed with wheat remained high throughout development. Serine protease activity also varied according to diets. These results show that the nutritional state of developing larvae varies greatly with respect to triglycerides, carbohydrate and digestive enzymes depending on the diet and larval stage. Altogether, these results show that changes in dietary nutrients can interfere with insect physiology. Therefore changes in diet composition that may deprive insects of essential nutrients or include toxic compounds might be a good control strategy for stored product pests.     

Coffee quality and its relationship with Brix degree and colorimetric information of coffee cherries

Coffee is a product whose value is stipulated according to its quality, which in turn depends on the stage of maturity of its fruits—the more mature its fruits, the higher the coffee value. The objective of this work was to analyze the level of soluble solids in coffee samples, determine the spectral signature of the fruits and their chromatic information, and correlate this information with the global quality of the beverage. Coffee cherry samples were collected from four plantations in the municipality of Araponga, Minas Gerais, Brazil. They were submitted to spectral and colorimetric analyses and used to determine the Brix degree. The samples were submitted to a quality test to determine the global coffee quality. The results were submitted to Pearson’s analysis of correlation followed by spatial variability mapping of each variable in each plantation. A linear regression analysis was also conducted to generate models capable of explaining the relationship between variables. Global coffee quality has significant correlation only with R band and fruit reflectance values. It is possible to use information from these variables to predict coffee quality while still in the plantation field.     

Antiproliferative effect of Canavalia brasiliensis lectin on B16F10 cells

Lectins are proteins or glycoproteins with the ability to link to carbohydrates at the cell surface in a specific and reversible manner. Studies have showed that lectins are demonstrate immunomodulatory and antitumor agents. This study aims to evaluate the effect of lectin extracted from the seeds of Canavalia brasiliensis (ConBr) on murine melanoma B16F10 cells by analyzing cell viability, apoptosis index, cell migration, production of cytokines and nitric oxide (NO). Results showed that ConBr was able to reduce cell viability and thwart apoptosis, which could be observed by decrease in cell migration. ConBr also induced NO and IL-12 synthesis. Altogether, these data demonstrate the potential of ConBr as a therapeutic agent for melanoma.     

Effect of the inhibitors phenylalanine arginyl ß-naphthylamide (PAßN) and 1-(1-naphthylmethyl)-piperazine (NMP) on expression of genes in multidrug efflux systems of Escherichia coli isolates from bovine mastitis

The multidrug efflux system in bacteria can reduce antibiotic concentration inside the cell, leading to failure in the treatment of bacterial diseases. This study evaluated the influence of two efflux pump inhibitors (EPIs), phenylalanine arginyl ß-naphthylamide (PAßN) and 1-(1-naphthylmethyl)-piperazine (NMP), on the gene expression of three multidrug efflux systems, AcrAB, AcrEF and EmrAB in Escherichia coli bovine mastitis isolates resistant to ampicillin and sulfamethoxazole/trimethoprim simultaneously. Each isolate had at least three multidrug efflux system genes. The acrA and acrB had the lowest expression levels in all treatments, while the emrA or emrB showed the highest expression levels in the presence of ampicillin, sulfamethoxazole/trimethoprim, PAβN and NMP. EPIs also contributed to the decrease in arcF expression when used in combination with ampicillin treatment. Since PAßN showed stronger effects than NMP, it may serve as an alternative to assist in the antimicrobial therapy of mastitis.     

Identification,occurrence and clinical findings of canine hemoplasmas in southern Brazil

Hemoplasmas are ubiquitous pleomorphic and epicellular bacteria detected in erythrocytes in several species. In Brazil, studies on hemoplasmas have not included information on occurrence, clinical signs, and risk factors in dogs. This paper investigates the occurrence of hemoplasmas in dogs, focusing on risk factors and clinical status. Conventional PCR for the four types of canine hemoplasmas was performed in 331 blood samples collected from dogs clinically treated at a teaching veterinary hospital. Of all samples, 17/331 (5.1%) were positive for Mycoplasma haemocanis and 6/331 (1.8%) were positive for a ‘Candidatus Mycoplasma haemominutum-like’ organism. Risk factors included the presence of vectors, old age, dog bite wounds, and neoplastic diseases. In the multivariate analysis, a 4.40 odds ratio in dogs with vector-borne diseases indicated risk for hemoplasmosis. There was correlation between hemoplasma infection and neoplastic disease, suggesting that neoplastic conditions are a risk factor for hemoplasma infection in dogs.     

Prevalence and molecular identification of Chlamydia abortus in commercial dairy goat farms in a hot region in Mexico

The aim of this study was to determine the seroprevalence and presence of Chlamydia abortus in Saanen breed female goats from commercial dairy goat farms under intensive production in the municipality of Guanajuato, Mexico. Sera were collected to determine the prevalence of anti-C. abortus IgG antibodies using recombinant enzyme-linked immunosorbent assay (rELISA) and cell culture. Polymerase chain reaction (PCR) was used to prove the presence of the pathogen in swab samples collected from the vagina and rectum of selected animals. Additionally, foetal tissue samples from a sudden abortion were collected. C. abortus prevalence in female goats of commercial milking farms sampled in Guanajuato, Mexico, was 4.87 % (n?=?246). Seropositive animals were found in six out of nine (66.6 %) dairy goat farms sampled, and prevalence among animals in individual farms ranged between 3.44 and 13.51 %. C. abortus was detected using PCR in spleen tissue from the aborted foetus. PCR-based detection, as well as isolation from vaginal and rectal swabs, was not possible in the present study. Isolation through cell culture was also unsuccessful from aborted foetal tissue samples. In conclusion, the results from rELISA and PCR show that C. abortus is present in dairy goat farms in the state of Guanajuato, Mexico.     

Herd-of-origin effect on the post-weaning performance of centrally tested Nellore beef cattle

The objective of a performance test station is to evaluate the performance of potential breeding bulls earlier in order to decrease the generation interval and increase genetic gain as well. This study evaluates the herd-of-origin influence on end-of-test weight (ETW), average daily weight gain during testing (ADG), average daily weight gain during the adjustment period (ADG_adj), rib eye area (REA), marbling (MARB), subcutaneous fat thickness (SFT), conformation (C), early finishing (EF), muscling (M), navel (N) and temperament (T) scores, and scrotal circumference (SC) of Nellore cattle that underwent a performance test. We evaluated 664 animals that participated in the performance tests conducted at the Center for Performance CRV Lagoa between 2007 and 2012. Components of variance for each trait were estimated by an animal model (model 1), using the restricted maximum likelihood method. An alternative animal model (model 2) included, in addition to the fixed effects present in S1, the non-correlated random effect of herd-year (HY). A significant HY effect was observed on ETW, REA, SFT, ADG_adj, C, and C_w (p?相似文献