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91.
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93.
O. A. A. Lopes de Sá M. A. S. Lara A. R. Evangelista T. F. Bernardes D. R. Casagrande 《Grass and Forage Science》2015,70(2):335-340
Understanding the morpho-physiological responses of forage plants is critical for successfully managing pastures; however, there is no specific method for morphogenetically assessing Arachis pintoi. The present study aimed to develop and validate mathematical models to estimate leaf area in A. pintoi to enable assessments of leaf elongation and senescence. Two experiments were performed. The first experiment used 500 A. pintoi leaves to model leaf area. Three models were used: correlation, mechanistic and empirical. A total of 336 leaflets were collected to validate the models. For the second experiment, 786 leaflet pairs were collected to test the leaf symmetry. Leaf length (L), width (W) and area (A) were measured for each leaflet in both of the experiments. The model identity test was used. The leaflet area can be estimated using the following formula: Â = W ×L × 0·25 × π. Experiment 2 showed that the initial leaflet pairs were equal, as were the terminal leaflet pairs. In conclusion, the mechanistic model should be used to estimate the leaf area for A. pintoi, and only half of each leaf can be measured. 相似文献
94.
JLA Martins AISB Villaverde AFM Lima PVM Steagall JCP Ferreira CA Taconeli MD Lopes 《Reproduction in domestic animals》2009,44(S2):366-368
The aim of this study was to investigate the impact of a 24-h cooling period prior to freezing on domestic cat epididymal sperm viability. Fifteen tomcats were submitted to routine orchiectomy and sperm samples were retrieved from both epididymides in a Tris–glucose–20% egg yolk extender. For each tomcat, the diluted sperm was split into two equal volumes and cooled to 5°C at a rate of 0.5°C/min; one sample for 60 min (control) and the other for 24 h (cooled). After the cooling period, samples from both groups were frozen using an identical freezing protocol. Sperm samples were evaluated in three different periods: immediately after harvesting, after cooling at 5°C for 24 h (cooled group) and after freezing–thawing of control and cooled groups. Evaluations consisted of sperm motility and progressive status, sperm morphology and plasma membrane integrity (PMI) using two fluorescent probes. After cooling for 24 h, a decrease (p < 0.05) in sperm motility, progressive status and PMI was observed when compared to sperm samples immediately after collection. Comparing the results obtained after thawing, no difference (p < 0.05) was found regarding sperm motility, progressive status, PMI and sperm morphology between control and cooled groups. The results from the present study show that cooling cat epididymal spermatozoa at 5°C for 24 h prior to freezing does not lead to major damage of spermatozoa impairing the freeze–thaw process. 相似文献
95.
A.M. Ramos R.H. Pita M. Malek P.S. Lopes S.E.F. Guimarães & M.F. Rothschild 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2009,126(5):404-412
In the mouse, homozygous animals for the high growth mutation show a 30–50% increase in growth without becoming obese. This region is homologous to the distal part of pig chromosome 5 (SSC5). A previous genome scan detected several quantitative trait loci (QTL) in this region for body composition and meat quality using a three generation Berkshire × Yorkshire resource family. In this study, the effects on swine growth, fat and meat quality traits of three genes previously identified within the mouse high growth region were analysed. The genes studied were CASP2 and RIPKI domain containing adaptor with death domain ( CRADD ), suppressor of cytokine signalling 2 ( SOCS2 ) and plexinC1 ( PLXNC1 ). In addition, the influence of two other genes located very close to this region, namely the plasma membrane calcium-transporting ATPase 1 ( ATP2B1 ) and dual specificity phosphatase 6 ( DUSP6 ) genes, was also investigated. Single nucleotide polymorphisms were identified and used to map these genes to the QTL region on SSC5. Results indicate significant associations between these genes and several phenotypic traits, including fat deposition and growth in pigs. The present study suggests associations of these genes with swine fat and growth related traits, but further studies are needed in order to clearly identify the genes involved in the regulation of the QTL located on SSC5. 相似文献
96.
Matias Bermann Daniela Lourenco Vivian Breen Rachel Hawken Fernando Brito Lopes Ignacy Misztal 《Journal of animal science》2021,99(4)
The introduction of animals from a different environment or population is a common practice in commercial livestock populations. In this study, we modeled the inclusion of a group of external birds into a local broiler chicken population for the purpose of genomic evaluations. The pedigree was composed of 242,413 birds and genotypes were available for 107,216 birds. A five-trait model that included one growth, two yield, and two efficiency traits was used for the analyses. The strategies to model the introduction of external birds were to include a fixed effect representing the origin of parents and to use unknown parent groups (UPG) or metafounders (MF). Genomic estimated breeding values (GEBV) were obtained with single-step GBLUP using the Algorithm for Proven and Young. Bias, dispersion, and accuracy of GEBV for the validation birds, that is, from the most recent generation, were computed. The bias and dispersion were estimated with the linear regression (LR) method,whereas accuracy was estimated by the LR method and predictive ability. When fixed UPG were fit without estimated inbreeding, the model did not converge. In contrast, models with fixed UPG and estimated inbreeding or random UPG converged and resulted in similar GEBV. The inclusion of an extra fixed effect in the model made the GEBV unbiased and reduced the inflation. Genomic predictions with MF were slightly biased and inflated due to the unbalanced number of observations assigned to each metafounder. When combining local and external populations, the greatest accuracy can be obtained by adding an extra fixed effect to account for the origin of parents plus UPG with estimated inbreeding or random UPG. To estimate the accuracy, the LR method is more consistent among scenarios, whereas the predictive ability greatly depends on the model specification. 相似文献
97.
I. V. Yevdokimov A. A. Larionova M. Schmitt V. O. Lopes de Gerenyu M. Bahn 《Eurasian Soil Science》2010,43(12):1373-1381
The contributions of root and microbial respiration to the total emission of CO2 from the surface of gray forest and soddy-podzolic soils were compared under laboratory and field conditions for the purpose
of optimizing the field version of the substrate-induced respiration method. The magnification coefficients of respiration
upon the addition of saccharose (k
mic) were first determined under conditions maximally similar to the natural conditions. For this purpose, soil cleared from
roots was put into nylon nets with a mesh size of 40 μm to prevent the penetration of roots into the nets. The nets with soil
were left in the field for 7–10 days for the compaction of soil and the stabilization of microbial activity under natural
conditions. Then, the values of k
mic were determined in the root-free soil under field conditions or in the laboratory at the same temperature and water content.
The contribution of root respiration as determined by the laboratory version of the substrate-induced respiration method (7–36%)
was lower compared to two field versions of the method (27–60%). Root respiration varied in the range of 24–60% of the total
CO2 emission from the soil surface in meadow ecosystems and in the range of 7–56% in forest ecosystems depending on the method
and soil type. 相似文献
98.
Nednaldo Dantas-Santos Jailma Almeida-Lima Arthur Anthunes Jacome Vidal Dayanne Lopes Gomes Ruth Medeiros Oliveira Silvia Santos Pedrosa Paula Pereira Francisco Miguel Gama Hugo Alexandre Oliveira Rocha 《Marine drugs》2012,10(9):2002-2022
Sulfated fucans comprise families of polydisperse natural polysaccharides based on sulfated L-fucose. Our aim was to investigate whether fucan nanogel induces cell-specific responses. To that end, a non toxic fucan extracted from Spatoglossum schröederi was chemically modified by grafting hexadecylamine to the polymer hydrophilic backbone. The resulting modified material (SNFuc) formed nanosized particles. The degree of substitution with hydrophobic chains was close to 100%, as estimated by elemental analysis. SNFfuc in aqueous media had a mean diameter of 123 nm and zeta potential of −38.3 ± 0.74 mV, as measured by dynamic light scattering. Nanoparticles conserved their size for up to 70 days. SNFuc cytotoxicity was determined using the MTT assay after culturing different cell lines for 24 h. Tumor-cell (HepG2, 786, H-S5) proliferation was inhibited by 2.0%–43.7% at nanogel concentrations of 0.05–0.5 mg/mL and rabbit aorta endothelial cells (RAEC) non-tumor cell line proliferation displayed inhibition of 8.0%–22.0%. On the other hand, nanogel improved Chinese hamster ovary (CHO) and monocyte macrophage cell (RAW) non-tumor cell line proliferation in the same concentration range. The antiproliferative effect against tumor cells was also confirmed using the BrdU test. Flow cytometric analysis revealed that the fucan nanogel inhibited 786 cell proliferation through caspase and caspase-independent mechanisms. In addition, SNFuc blocks 786 cell passages in the S and G2-M phases of the cell cycle. 相似文献
99.
Federico Ferreres Graciliana Lopes Angel Gil-Izquierdo Paula B. Andrade Carla Sousa Teresa Mouga Patrícia Valent?o 《Marine drugs》2012,10(12):2766-2781
Purified phlorotannin extracts from four brown seaweeds (Cystoseira nodicaulis (Withering) M. Roberts, Cystoseira tamariscifolia (Hudson) Papenfuss, Cystoseira usneoides (Linnaeus) M. Roberts and Fucus spiralis Linnaeus), were characterized by HPLC-DAD-ESI-MSn. Fucophloroethol, fucodiphloroethol, fucotriphloroethol, 7-phloroeckol, phlorofucofuroeckol and bieckol/dieckol were identified. The antioxidant activity and the hyaluronidase (HAase) inhibitory capacity exhibited by the extracts were also assessed. A correlation between the extracts activity and their chemical composition was established. F. spiralis, the species presenting higher molecular weight phlorotannins, generally displayed the strongest lipid peroxidation inhibitory activity (IC50 = 2.32 mg/mL dry weight) and the strongest HAase inhibitory capacity (IC50 = 0.73 mg/mL dry weight). As for superoxide radical scavenging, C. nodicaulis was the most efficient species (IC50 = 0.93 mg/mL dry weight), followed by F. spiralis (IC50 = 1.30 mg/mL dry weight). These results show that purified phlorotannin extracts have potent capabilities for preventing and slowing down the skin aging process, which is mainly associated with free radical damage and with the reduction of hyaluronic acid concentration, characteristic of the process. 相似文献
100.
Vanessa Dias Capriles Eveline Lopes Almeida Reinaldo Eduardo Ferreira Jos Alfredo Gomes Arêas Caroline Joy Steel Yoon Kil Chang 《Cereal Chemistry》2008,85(5):614-618
The sum of wheat flour and corn starch was replaced by 10, 20, or 30% whole amaranth flour in both conventional (C) and reduced fat (RF) pound cakes, and the effects on physical and sensory properties of the cakes were investigated. RF presented 33% fat reduction. The increasing amaranth levels darkened crust and crumb of cakes, which decreased color acceptability. Fresh amaranth‐containing cakes had similar texture characteristics to the controls, evaluated both instrumentally and sensorially. Sensory evaluation revealed that replacement by 30% amaranth flour decreased C cakes overall acceptability scores, due to its lower specific volume and darker color. Amaranth flour levels had no significant effect on overall acceptability of RF cakes. Hence, the sum of wheat flour and corn starch could be successfully replaced by up to 20% amaranth flour in C and up to 30% in RF pound cakes without negatively affecting sensory quality in fresh cakes. Moisture losses for all the cakes were similar, ≈1% per day during storage. After six days of storage, both C and RF amaranth‐containing cakes had higher hardness and chewiness values than control cakes. Further experiments involving sensory evaluation during storage are necessary to determine the exact limit of amaranth flour replacement. 相似文献