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51.
Cristina Rodríguez-García Fernando Montes Federico Ruiz Isabel Cañellas Pilar Pita 《European Journal of Forest Research》2014,133(5):895-904
Sustainable forest management requires knowledge of forest structure and dynamics as well as an estimation of growing stock. The forest inventory provides the data for estimating stand variables. The measurement device MU2005-01738, patented by the Center for Forest Research (INIA-CIFOR), provides stereoscopic hemispherical images which can allow the 3D restoration of the stand around the sampling point. The aim of this study is to develop a methodology for forest stand mapping as well as tree diameter and height measurement along with volume estimation from the stereoscopic hemispherical images provided by the MU2005-01738. Using the MU2005-01738, Eucalyptus globulus Labill. plantations were sampled. Distance, diameter, height and volume were derived from the stereoscopic hemispherical images of 30 trees located at distances ranging from 0 to 15 m from the device. These variables were then compared with field measurements and the estimation errors analyzed. The (root-mean-squared error) RMSE was 0.23 m (8.95 %) for tree position and 1.51 cm (10.43 %) for diameter at breast height measurement at distances of less than 8 m. In the case of stem height and individual tree volume estimation, the RMSE was 2.59 m (23.05 %) and 0.025 m3 (17.94 %), respectively. The analysis of measurement errors indicated that the measurement precision decreases beyond 8 m from the device as well as for directions close to the baseline (the line between the optical centers of the two images), whereas the precision was highest for directions near to the line which is perpendicular to the base line. Future research should focus on improving measurement accuracy and possible applications in the field of forestry of the techniques presented in this study. 相似文献
52.
Sofia Knapic Vanda Oliveira Marika Makkonen Isabel Pinto-Seppä Helena Pereira 《European Journal of Forest Research》2014,133(6):1007-1014
Maritime pine (Pinus pinaster Ait.) is an important timber and pulpwood species covering about 4 million ha in Portugal, Spain and France. This work studied the cross-sectional distribution of heartwood and sapwood along the stem using 3D modelling on 20 trees. The target was to assess the potential of this species for the industrial production of heartwood sawn products. The maritime pine stems were characterized by wide sapwood of 10 cm, in average, and the presence of heartwood at all height levels with constant diameter up to 35 % tree height, decreasing afterwards. In the radial section, the heartwood follows a circumferential-like shape which changes along the stem. Pith eccentricity index values were low and homogeneous regarding to stem and higher for heartwood. Heartwood cross-sectional shape was constant up to 45 % of total height of the tree and more elongated upwards. The constant heartwood diameter, low taper and pith eccentricity index, and an approximate circular shape up to 10 m height indicated these species’ potential to produce solid wood products made out of heartwood. 相似文献
53.
Some aspects of the reproductive biology of Charybdis feriatus (Linnaeus) were investigated to identify suitable techniques for broodstock management and seed production. Likewise, factors such as ablation, water depth and light requirements affecting survival or reproductive performance were tested. Production of megalops in tanks and juveniles in net cages installed in earthen ponds was conducted. Wild‐caught berried females produced a significantly higher number of zoeae per gram body weight (BW) of the female (3300±600) than captive spawners (867±58). Ablated and unablated crabs spawned after a month and ovaries of both had oocytes in all developmental stages after spawning, indicating that ablation was not necessary. Broodstock survived higher when stocked in 1 m‐deep water and kept in dark conditions compared with shallow (0.5 m depth) water or ambient lighting. There were six zoea and one megalopa stage. Megalops were produced (survival of 2–22% in 1 tonne or 23–55% in 3 L tanks) when methods for the mud crab Scylla serrata (Forsskål) were used, but feeding with Artemia started only at the Z4 stage. Survival of megalops after 1 month was higher when stocked in net cages installed in an earthen pond (32–82%) than when reared continuously in land‐based tanks (5–11%). 相似文献
54.
Andreia Lemos Ana Isabel Freitas Ana Teresa Fernandes Rita Gonçalves José Jesus Carlos Andrade & António Brehm 《Aquaculture Research》2006,37(10):1028-1033
Eight microsatellite loci previously reported were assessed for their utility in parentage assignment in 96 individuals belonging to natural populations of the blackspot seabream Pagellus bogaraveo (Brünnick, 1768) from the Mediterranean and Northeast Atlantic regions. At the mtDNA level, no differentiation was found between these two regions but based on microsatellite data an overall discrete genetic differentiation is perceivable between the two regions separated by the Strait of Gibraltar. The number of alleles per locus ranged from 8 to 30. A database constructed with allele frequency data from six populations was used in a simulation parentage assignment test using the software cervus . The test showed that the number of markers used is enough to perform parentage assignments with real data. The polymorphic information content for each locus was very high (mean value of 0.849), with a total exclusionary power of 0.9995. In summary, seven of the eight microsatellites analysed proved to be sufficient and powerful tools for parentage assignment in hatcheries and the allele frequency data given here can be used to perform pedigree analysis against which real data may be tested. 相似文献
55.
Silvia Carolina Moreno-Rivas Concepción Lorenia Medina-Rodríguez Patricia Isabel Torres-Chávez Benjamín Ramírez-Wong Luis Carlos Platt-Lucero 《Plant foods for human nutrition (Dordrecht, Netherlands)》2014,69(2):148-154
The extrusion process allows the production of nixtamalized corn flour rich in arabinoxylans, which help to prevent cardiovascular and intestinal diseases. During extrusion, physiochemical properties of nixtamalized corn flour are negatively modified. The use of enzymes such as xylanase in order to obtain nixtamalized corn flour using extrusion has been studied as an alternative to reduce these changes in corn flour tortilla. The aim of this research was to evaluate changes in protein solubility of extruded nixtamalized corn flour with and without different concentrations of xylanase enzyme (0.05, 0.075, and 0.1 %, w/w). Soluble proteins of each corn flour were extracted and analyzed by SE-HPLC, while insoluble proteins were determined by the combustion method. In addition, each corn flour was analyzed by scanning electron microscopy (SEM). Results showed that the extruded nixtamalized corn flour, with and without xylanase, increased the protein solubility, and this effect was lower in extruded nixtamalized corn flour with xylanase. Insoluble protein diminished in corn flours either with or without xylanase enzyme. The addition of xylanase reduces the effect that the extrusion process has on the solubility proteins of extruded nixtamalized corn flour. 相似文献
56.
57.
Jesus Mellado Edgar Sepulveda Jose E Garcia Alvaro Rodriguez Maria A De Santiago Francisco G Veliz Miguel Mellado 《中国农业科学(英文版)》2014,(6):1349-1354
Nineteen multiparous barren Holstein cows were subjected to an induction of lactation protocol for 21 d administering estradiol cypionate (2 mg kg-1 of body weight (BW) d-1, on day 1 to 14), progesterone (0.10 mg kg-1 of BW, on day 1 to 7), lfumethasone (0.03 mg kg-1 of BW, on day 18 to 20) and recombinant bovine somatotropin (rbST;500 mg per cow, on day 1, 6, 16 and 21). At the end of lactation and with a minimum of a 2-mon dry period, the same cows were again hormonally induced into lactation. Cows in both lactations were not artiifcially inseminated, they were milked 3 times daily and received rbST throughout lactation. Mean accumulated milk yield at 305 d in milk (DIM) did not differ between the ifrst and second induced lactations ((9 710 ±1 728) vs. (9 309±2 150) kg;mean±SD). Total milk yield ((12 707±3 406) vs. (12 306±4 218) kg;mean±SD) and lactation length ((405±100) vs. (410±91) d;mean±SD) were not different between the ifrst and second induced lactations. In a second study, 15 empirical models including exponential, power law, yield-density, sigmoidal and miscellaneous models were compared for their suitability by modeling 12-mon (n=334), 18-mon (n=164) and 29-mon (n=22) lactation cycles of Holsteins cows induced into lactation and treated with rbST throughout the lactation. Hoerl (Y=ab1/xxc), Wood (Y=axb exp(cx)) and Dhanoa (Y=ax(bc)exp(cx)) models were equally suitable to describe 12-mon lactations. An exponential model with ifve parameters (Y=exp(a+bx+cd2+e/x)) showed the best ift for milk yield for 18-mon lactations. The rational model (Y=a+bx/1+cx+dx2) was found to produce the closest ift for 29-mon lactations. It was concluded that, with the protocol used in the present study, multiparous cows respond favorably to a second cycle of induced lactation, with milk yield similar to that experienced during the ifrst cycle. Thus, dairy producers might be able to lengthen the productive life of infertile high producing cows with a renewal of artiifcial lactation, which would imply an overall reduction in voluntary culling of cows. Also, various equations used to describe the lactation curves demonstrated the potential for iftting monthly milk records of Holstein cows with prolonged lactations and induced hormonally into lactation. 相似文献
58.
J. Ruberte J. Y. Sautet J. M. Gine C. Lopez A. Rodriguez 《Anatomia, histologia, embryologia》1990,19(4):347-358
The topography of the lymph drainage was examined by in vivo injections of india ink into the mammary parenchyma of 73 female dogs. Only one gland was injected at a time on each side. Only the cranial abdominal mammary gland had direct drainage to the axillary as well as to the superficial inguinal nodes. The principal routes of drainage differ for each gland. The glands on each side are completely independent as regards their lymph drainage. The cranial thoracic mammary glands on each side had their own collecting duct which led to the sternal lymph nodes. The results of this study suggest to develop a new model for the surgical extirpation of mammary tumors in the bitch. 相似文献
59.
David Fernndez‐Calvio Lorena Prez‐Armada Laura Cutillas‐Barreiro Remigio Paradelo‐Núez Avelino Núez‐Delgado María J. Fernndez‐Sanjurjo Esperanza lvarez‐Rodriguez Manuel Arias‐Estvez 《Land Degradation \u0026amp; Development》2016,27(4):1276-1285
Mining activities are related to relevant environmental pollution issues that should be controlled. We used sequential extractions to fractionate Cd, Cu, Ni, Pb and Zn retained on unamended or mussel shell‐amended mine soil samples, all of them treated with a mixture of the five heavy metals (total metal concentration of 1·57 mmol L−1), after 1, 7 and 30 days of incubation. In addition, we used the stirred flow chamber technique to study the release of each of the five heavy metals from these different unamended and shell‐amended soil samples. The results indicate that the shell amendment caused a decrease in the most soluble fraction, while increasing the most recalcitrant (least mobile) fraction. With equivalent implications, the stirred flow chamber experiments showed that mussel shell amendment was associated to a decrease in heavy metal release and increased retention. The highest mussel shell dose and incubation time caused the most relevant changes in pH values and thus in metal retention, also indicating the importance of pH modifications in the mechanism of retention acting in the amended samples. In view of these results, the use of mussel shell amendment can be encouraged to increase heavy metal retention in acid mine soils, in order to minimise risks of environmental pollution. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
60.
Summary Chromosome number of morphogenic and non-morphogenic calli and regenerated plants of barley were determined. Cultures were obtained from two kinds of explants, immature embryos and seedling leaves from three cultivars, Ingrid, Dissa and Golden Promise. Callus chromosome analyses were carried out during a 12 month period in a medium containing 2 mg/l of 2,4-D. Diploid cells were predominant in all cases; although in leaf-derived cultures, retraploid cells (2n=4x=28) showed a tendency to increase as time in culture increased and after more than six months in culture, diploid cells decreased to percentages of almost 70%. Aneuploid cells were generally infrequent in all cases. The source of explant has been more important than the genotype (cultivar) and the type of callus (morphogenic vs. non-morphogenic) in the chromosomal stability of cultures as time increases. From short term cultures, only 1.85% of the regenerated plants were tetraploid, the remaining were diploids. The ability of morphogenic calli to regenerate plants decreased before any significant reduction of diploid cells were observed. 相似文献