Effect of increasing densities of Urochloa brizantha cv. Marandu on Eucalyptus urograndis initial development in silvopastoral system     

Michel Anderson Almeida Colmanetti  Allan Lopes Bacha  Pedro Luis da Costa Aguiar Alves  Rinaldo Cesar de Paula 《林业研究》2019,(2):537-543

In silvopasture system, the coexistence of eucalyptus seedlings with other species may result in growth reduction, especially during eucalyptus early development.Therefore, studies elucidating how forage species affect the eucalyptus growth can provide important information for their rational management aiming to obtain the maximum gain of the system. The aim of this work was to evaluate the effect of increasing densities of Urochloa brizantha cv.Marandu in the early development of Eucalyptus urograndis. An experiment was conducted in 20 L pots, in an open and semi-controlled area, during 90 days after planting of eucalyptus. A completely randomized design with four replications was used, in a 6 9 7 factorial system, meaning six evaluation periods and seven densities of U. brizantha: 0(control), 22, 33, 44, 67, 89 and111 plants m^-2. Fortnightly, eucalyptus height, stem diameter and chlorophyll fluorescence(Fv/Fm) were evaluated. At the end of experimental period, the net assimilation rate, stomatal conductance and transpiration rate of eucalyptus plants were determined, in addition to the dry matter of eucalyptus(leaves and stem) and U. brizantha (leaves). In coexistence with 111 plants m^-2, eucalyptus had reduction of 63.9% on total dry matter and 72.7% on leaf area, compared to the control. From the density of22 plants m^-2, U. brizantha negatively interfere significantly the growth of E. urograndis. Up to 8 plants m^-2 there are no reductions greater than 5% in eucalyptus height and stem diameter.  相似文献   

Assessment and prediction of changes in the reserves of organic carbon in abandoned soils of European Russia in 1990–2020     

I. N. Kurganova  V. O. Lopes de Gerenyu 《Eurasian Soil Science》2008,41(13):1371-1377

Experimental studies and the analysis of published data have shown that carbon reserves in soils generally increase upon soil exclusion from agricultural use. The rate of carbon accumulation in the abandoned soils depends on the soil type, the time elapsed since the soil abandoning (the restoration period), and the thickness of the layer for which the rate of carbon accumulation is determined. For the upper 20-cm-thick layer, it varies from 66 to 175 g C/m² per year in dependence on the type of soil and averages 111 g C/m² per year. The highest rate is typical of the first 10–15 years of soil restoration. According to our calculations, the carbon sequestration in the upper 20-cm-thick layer of Russian soils due to changes in land use was 184–673 Mt C in 1990–2005 and may reach 282–1030 Mt C by 2020.  相似文献   

Secondary Stress Responses in Juvenile Brazilian Flounder,Paralichthys orbignyanus,throughout and after Exposure to Sublethal Levels of Ammonia and Nitrite     

Lucas C. Maltez  Luis A. L. Barbas  Marcelo H. Okamoto  Diogo L. de Alcantara Lopes  Luis A. Romano  Luís A. Sampaio  Luciano Garcia 《Journal of the World Aquaculture Society》2019,50(2):346-358

This study investigated the secondary stress responses of Paralichthys orbignyanus exposed to ammonia and nitrite and after recovery. Fish were exposed to 0.12, 0.28, and 0.57 mg NH₃‐N/L, or 5.72, 10.43, and 15.27 mg NO₂‐N/L for 10 d followed by the same time length for recovery. Ammonia‐ and nitrite‐free water was used as a control treatment. Blood samples were collected after 1, 5, and 10 d of exposure and after recovery. Fish exposed to ammonia presented lower and higher glucose levels after 10 d of exposure and recovery, respectively. Ammonia induced initial and transient ionic disturbances and metabolic alkalosis. Nitrite exposure caused hyperglycemia, increased plasma K⁺ levels, and respiratory alkalosis, whereas metabolic acidosis was observed after recovery. Increased proportion of monocytes and/or granulocytes and reduced number of lymphocytes were demonstrated in fish exposed to 0.28 mg NH₃‐N/L (Day 1) and 10.43 mg NO₂‐N/L (Day 5) and after recovery in the 0.28 and 0.57 mg NH₃‐N/L treatments. Exposure to ammonia decreased the proportion of granulocytes on Day 5. In conclusion, exposure to concentrations at 0.12 mg NH₃‐N/L and 5.72 mg NO₂‐N/L provoked physiological disorders in Brazilian flounder. Nonetheless, fish exposed to 5.72 mg NO₂‐N/L following a 10‐d recovery period showed complete resumption of homeostasis.  相似文献   

Magnetic resonance imaging in the diagnosis of type 1 dermoid sinus in two Rhodesian ridgeback dogs     

Sheila Rahal  Ana Carolina Mortari  Seizo Yamashita  Miltom Morishin Filho  Eduardo Hatschbac  Júlio Lopes Sequeira 《The Canadian veterinary journal. La revue veterinaire canadienne》2008,49(9):871-876

Two cases of type 1 dermoid sinus in Rhodesian ridgebacks are described, with emphasis on the use of magnetic resonance imaging (MRI) in the diagnosis and delineation of the lesions. Magnetic resonance imaging was useful in identifying fluid-filled structures, fibrous capsules, and sinus tracts, but was not able to identify the termination of the tracts.  相似文献   

E-cadherin expression in canine cutaneous histiocytoma     

Pires I  Alves A  Rodrigues P  Queiroga FL  Lopes CS 《The Veterinary record》2008,163(2):59-60; author reply 60

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Are complex carcinoma of the feline mammary gland and other invasive mammary carcinoma identical tumours? Comparison of clinicopathologic features,DNA ploidy and follow up     

Seixas F  Palmeira C  Pires MA  Lopes C 《Research in veterinary science》2008,84(3):428-433

Feline mammary carcinomas are known for their unfavourable prognosis due to a strong tendency to local recurrence and metastasis. We studied 73 spontaneous primary mammary carcinomas and identified eight cases presenting a biphasic nature, with neoplastic epithelial and myoepithelial cells (complex carcinoma). These cases presented histopathologic features associated with a better prognosis; they were also associated with higher overall survival and disease-free survival rates compared to other common invasive mammary carcinomas of non-specified type. Complex carcinoma appears to be a low-grade malignancy.  相似文献   

Carcass characteristics and meat quality of sheep fed alfalfa hay to replace Bermuda grass hay     

da Silva  José Ricardo Coelho  de Carvalho  Francisco Fernando Ramos  de Andrade Fereira  Marcelo  de Souza  Evaristo Jorge Oliveira  Maciel  Maria Inês Sucupira  Barreto  Lígia Maria Gomes  Lopes  Levi Auto  Cordeiro  Eduardo Henrique Araújo  Véras  Antonia Sherlânea Chaves 《Tropical animal health and production》2019,51(8):2455-2463

Tropical Animal Health and Production - The objective of this study was to evaluate carcass characteristics, meat quality, and organ and viscera weight of forty male sheep, not castrated, initially...  相似文献   

Evaluation of transformation growth factor beta1, interleukin-10, and interferon-gamma in male symptomatic and asymptomatic dogs naturally infected by Leishmania (Leishmania) chagasi     

Corrêa AP  Dossi AC  de Oliveira Vasconcelos R  Munari DP  de Lima VM 《Veterinary parasitology》2007,143(3-4):267-274

The aims of this study were to evaluate the immunomodulatory role of TGF-β₁, IL-10, and INF-γ in spleen and liver extracts and supernatant cultures of white spleen cells from male symptomatic and asymptomatic dogs, naturally infected by Leishmania (Leishmania) chagasi. Thirty dogs from Araçatuba, São Paulo, Brazil, an endemic leishmaniosis area, were selected by positive ELISA serological reaction for Leishmania sp. and divided into two groups: asymptomatic (n = 15) and symptomatic (n = 15) consisting of animals with at least three characteristic signs (fever, dermatitis, lymphoadenopathy, onychogryphosis, weight loss, cachexia, locomotion problems, conjunctivitis, epistaxis, hepatosplenomegaly, edema, and apathy). After euthanasia, spleen and liver fragments were collected for ex vivo quantification of TGF-β₁, IL-10, and INF-γ. Naturally active in vitro produced TGF-β₁ was also evaluated in spleen cell culture supernatant. Spleen and liver extract of asymptomatic dogs had higher mean TGF-β₁ levels than symptomatic dogs. High concentrations of IL-10 were found in spleen, and mainly in liver extract of both groups. Higher INF-γ concentrations were found in spleen extracts of symptomatic dogs, and in liver extracts of asymptomatic dogs. Extract of this cytokine was lower in spleen extract. Although INF-γ is being produced in canine infection, mean levels of TGF-β₁ and IL-10 from spleen and liver extracts were quantitatively much higher; suggesting that immune response in both asymptomatic and symptomatic dogs was predominantly type Th2.  相似文献   

Physicochemical Properties of Maize Starch Obtained from Intermittent Milling and Dynamic Steeping (IMDS) Under Various Steeping Conditions     

E. A. Brandemarte  C. M. L. Franco  J. F. Lopes‐Filho 《Cereal Chemistry》2004,81(3):369-376

Physicochemical properties of maize starch obtained under different steeping conditions by intermittent milling and dynamic steeping process (IMDS) were studied. Brazilian dent maize (hybrid XL 606) was milled using a 2×2×3 factorial experimental design with two lactic acid levels (0.0 and 0.55%, v/v), two SO₂ levels (0.05 and 0.1%, w/v), and three temperatures (52, 60, and 68°C). Properties of starch obtained by conventional wet‐milling process (36 hr at 52°C, 0.55% lactic acid, and 0.2% SO₂) were used for comparison. Starch protein content and solubility increased with presence of lactic acid, while swelling power decreased. Higher SO₂ concentration (0.1%) had the same effect as lactic acid on some properties. Steeping temperatures of 60 and 68°C increased solubility and most of the thermal properties but reduced swelling power, suggesting stronger starch annealing during IMDS at these temperatures. Some thermal changes on starch granules were visualized by scanning electron microscopy (SEM) at 60 and 68°C. Amylose content as well as pasting properties were affected by steeping factors and interactions. Starches from IMDS and conventional wet‐milling processes were similar in most properties, indicating that IMDS provides starch with quality similar to that from conventional milling.  相似文献   

Inheritance of the stay-green trait in tropical maize     

Pedro Radi Belícuas  Aurélio Mendes Aguiar  Dyeme Antonio Vieira Bento  Tassiano Marinho Maxwell Câmara  Cláudio Lopes de Souza Junior 《Euphytica》2014,198(2):163-173

Stay-green maize genotypes have been associated with tolerance to biotic and abiotic stresses, including tolerance to drought, and to stalk and root lodging, but there is limited information on its inheritance. Thus, this research was conducted to study the inheritance of the stay-green trait using both conventional analysis and QTL mapping of the Design III in a tropical maize population developed from two inbred lines genetically divergent for this trait. Two-hundred and fifty F₂ plants were genotyped with 177 microsatellite markers, and their backcrossed progenies to both parental inbreds were evaluated at three locations. Ten plants per plot were assessed 120 days after sowing and the plot means scores for stay-green, adjusted for days to silking emergence, were used for analysis. The additive variance was larger than the dominance variance, the genetic by location interaction variance presented a high magnitude, and the heritability coefficient on a plant-basis a low magnitude. Seventeen QTL were mapped, most of them were clustered on four chromosomes and accounted for by 73.08 % of the genetic variance. About half of the QTL interacted with location, and the average level of dominance was partial dominance. The additive effects were larger than the dominance effects; the latter were not unidirectional, so that heterosis could not be exploited in crosses. Procedures for marker-assisted selection to increase the level of stay-green are discussed and an approach is suggested for using both stable and non-stable QTL in a marker-assisted backcross program.  相似文献