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231.
The main purpose of the present investigation is to examine and compare three methods for diameter distribution modeling in
terms of their fitness to predict from stand level variables the diameter distributions of even-aged Austrian black pine (Pinus nigra Arn.) plantations in Bulgaria. The percentile-based projection method involving empirical probability density function based
on 12 percentiles was the first method tested. A new modified approach based on the first method was proposed as the second
alternative. The third method was the 2-parameter Weibull functional model in which parameters were recovered from the first
and the second raw moments and the second central moment of the empirical distributions. The Kolmogorov–Smirnov test was applied
to compare the experimental distributions with the predicted ones, and estimation of the error indices was employed to evaluate
the total absolute deviation of the predicted numbers from the actual ones by diameter class. The two-parameter Weibull function
proved superior to the examined alternative percentile-based projection methods and the newly proposed percentile method,
without a driver percentile showed improved precision compared to the classical percentile method (with a driver percentile).
The parameters of the Weibull frequency distribution function can be easily recovered from the stand quadratic mean diameter.
Consequently, this diameter distribution model could be incorporated as a sub-model for stand horizontal structure characterization
within the Stand Density Management Diagram modeling framework. 相似文献
232.
Julio Beltrame Daleprane Tatiana Silveira Feijó Gilson Teles Boaventura 《Plant foods for human nutrition (Dordrecht, Netherlands)》2009,64(1):1-5
The aim of this study was to evaluate the protein quality of organic and genetically modified soy by feeding specific diets
to rats. Three groups of Wistar rats (n = 10) were used, and each group was named according to the food that they ate. There was an organic soy group (OG), a genetically
modified soy group (GG), and a control group (CG). All animals received water and diet ad libitum for 455 days. At the end of this period, the weight of the GG group was the same as that of the OG, and both were higher
than CG. Protein intake was similar for the OG and GG, which were significantly lower (p < 0.0005) than the CG. The growth rate (GR) of the rats, albumin levels, and total levels of serum protein were comparable
for all groups. Hematocrit (p < 0.04) and hemoglobin (p < 0.03) for the OG and GG were less than the CG. Although the OG and GG demonstrated reduced hematocrit and hemoglobin, both
types of soy were utilized in a way similar to casein. This result suggests that the protein quality of soy is parallel to
the standard protein casein in terms of growth promotion but not hematological indicators. 相似文献
233.
Tatiana M. Minkina Vitaly G. Linnik Dina G. Nevidomskaya Tatiana V. Bauer Saglara S. Mandzhieva Vitaliy Y. Khoroshavin 《Journal of Soils and Sediments》2018,18(6):2217-2228
Purpose
The aim was to study Cu (II), Zn (II), and Pb (II) forms in technogenically transformed soils adjacent to the Karabashmed copper smelter.Materials and methods
Studies were performed in the plume zone of the Karabash smelter and in the floodplains of Ryzhii Brook and Sak-Egla River. Geomorphological and geochemical migration processes prevail in technogenic landscapes. The differentiation of landscape-geochemical conditions plays the dominant role, which determines the localization of metals. The total Mn, Cr, Ni, Cu, Zn, Pb, Cd, and As contents and the macroelement compositions of soils were determined by X-ray fluorescence. The composition of Cu, Pb, and Zn compounds in soils was determined by the Tessier sequential fractionation. The determination of the geochemical fractions of heavy metals in soils is a key issue in the study of their mobility. The metals were fractionated into the following five fractions: exchangeable, bound to carbonates, bound to Fe and Mn oxides, bound to organic matter, and residual fractions.Results and discussion
It is shown that the total Zn and As contents in the 0- to 5-cm layer of soils on monitoring plots exceed their lithosphere clarks in hundreds of times, and the total Cu, Pb, and Cr contents exceed their lithosphere clarks in tens of times. Factors and processes controlling the distribution and transport of Cu, Pb, and Zn forms in soils were determined. According to landscape-geochemical differentiation, the eluvial (automorphic) catena (plot T4) takes the main technogenic load of dust fallouts from the Karabash copper smelter. The accumulation of material brought from above and the geochemical precipitation of discharges from tailings dumps occur in superaqual catenas (plots T1, T2, and T3). In the technogenically transformed soils, the basic stabilizers of the mobility of Cu is organic matter, for Pb it is Fe-Mn (hydro) oxides, and for Zn - it is clay minerals.Conclusions
The distributions of Cu, Zn, and Pb forms in the studied technogenically transformed soils are due to a number of factors: First, these are the composition of technogenic pollutants contaminating ecosystems and the time during which the contamination occurred, and second, this is the combination of physicochemical properties controlling the buffer properties of the polydisperse system of soils and parent materials.234.
Almazán-Sánchez Perla Tatiana Marin-Noriega Paul William González-Mora Eduardo Linares-Hernández Ivonne Solache-Ríos Marcos J. Martínez-Cienfuegos Iván G. Martínez-Miranda Verónica 《Water, air, and soil pollution》2017,228(8):1-26
Water, Air, & Soil Pollution - Biochar presents great promise as a technology that makes a substantial contribution in various fields of environmental research. However, existing knowledge is... 相似文献
235.
Leandro Cesar Godoy Clarisse Odebrecht Eduardo Ballester Tatiana Germano Martins Wilson Wasielesky Jr. 《Aquaculture International》2012,20(3):559-569
Bio-floc shrimp culture systems have been investigated in an attempt to optimize water use and prevent the discharge of effluent into the environment. The importance of microalgae in maintaining water quality and nutrition of the shrimp is well known in conventional systems; however, its maintenance amid bio-flocs and its role in the shrimp performance in this system are still poorly understood. The aim of this study was to evaluate the contribution of diatoms in the performance of Litopenaeus vannamei reared during the nursery phase in intensive system with minimal water exchange. Shrimp (0.31?±?0.10?g) were reared among diatoms, bio-flocs and the combination of the two forming the mixture medium. The survival of shrimp was high in all treatments (90?C97%). However, the shrimp reared among diatoms showed higher weight gain (P?<?0.05) and feed conversion ratio significantly more efficient, reaching a value of 0.47. The results indicate the importance of diatoms in bio-floc culture systems and points out to future research in an attempt to maintain a constant presence of these microalgae in culture medium without requiring successive inoculations. 相似文献
236.
van Erck E Votion DM Kirschvink N Art T Lekeux P 《American journal of veterinary research》2003,64(11):1414-1420
OBJECTIVE: To compare sensitivity of the impulse oscillometry system (IOS) with that of the conventional reference technique (CRT; ie, esophageal balloon method) for pulmonary function testing in horses. ANIMALS: 10 horses (4 healthy; 6 with recurrent airway obstruction [heaves] in remission). PROCEDURE: Healthy horses (group-A horses) and heaves-affected horses (group-B horses) were housed in a controlled environment. At each step of a methacholine bronchoprovocation test, threshold concentration (TC(2SD); results in a 2-fold increase in SD of a value) and sensitivity index (SI) were determined for respiratory tract system resistance (R(rs)) and respiratory tract system reactance (X(rs)) at 5 to 20 Hz by use of IOS and for total pulmonary resistance (RL) and dynamic lung compliance (C(dyn)), by use of CRT. RESULTS: Bronchoconstriction resulted in an increase in R(rs) at 5 Hz (R(5Hz)) and a decrease in X(rs) at all frequencies. Most sensitive parameters were X(rs) at 5 Hz (X(5Hz)), R(5Hz), and R(5Hz):R(10Hz) ratio; RL and the provocation concentration of methacholine resulting in a 35% decrease in dynamic compliance (PC(35)C(dyn)) were significantly less sensitive than these IOS parameters. The TC(2SD) for X(rs) at 5 and 10 Hz was significantly lower in group-B horses, compared with group-A horses. The lowest TC(2SD) was obtained for X(5Hz) in group-B horses and R(5Hz) in group-A horses. CONCLUSIONS AND CLINICAL RELEVANCE: In contrast to CRT parameters, IOS parameters were significantly more sensitive for testing pulmonary function.The IOS provides a practical and noninvasive pulmonary function test that may be useful in assessing subclinical changes in horses. 相似文献
237.
Maria Alice Schnaider Henrique Mendonça Nunes Ribeiro-Filho Gilberto Vilmar Kozloski Tatiana Reiter Aline Cristina Dall Orsoletta Ademar Luiz Dallabrida 《Tropical animal health and production》2014,46(6):975-980
The aim of this study was to evaluate the effect of the inclusion of peanut (Arachis pintoi cv. Amarillo) hay in diets based on dwarf elephant grass (DEG, Pennisetum purpureum Schum cv. Kurumi) hay of different regrowth ages on forage intake and digestibility in wether lambs. The experimental treatments consisted of DEG hay with an interval of regrowth of 30 or 45 days offered as the only feed or in mixture with peanut hay (300 g/kg of total dry matter (DM)), which were tested in eight Texel?×?Suffolk crossbred wethers in a replicated 4?×?4 Latin square experiment. Both organic matter (OM) and digestible OM intakes were higher (P?<?0.05) in animals receiving the legume forage. Total apparent OM digestibility was higher (P?<?0.05) at an increased grass regrowth age. Ruminal OM digestibility increased (P?<?0.05) with legume inclusion and at a higher grass regrowth age. The nitrogen (N) intake was higher (P?<?0.05) in legume treatments and lower (P?<?0.05) as the grass regrowth age increased, but retention of N was not affected by treatments. Duodenal flow of both, non-ammonia N and microbial N, were not affected by legume inclusion and were lower (P?<?0.05) as grass regrowth age increased. The efficiency of rumen microbial protein synthesis (ERMPS) was negatively affected (P?<?0.05) by legume inclusion and was lower (P?<?0.05) as the grass regrowth age increased. Supplementation of dwarf elephant grass hay cut at the vegetative stage with peanut legume hay improves nutritional supply to wethers due to an increase in the forage intake. 相似文献
238.
239.
Cheng EH Sheiko TV Fisher JK Craigen WJ Korsmeyer SJ 《Science (New York, N.Y.)》2003,301(5632):513-517
The multidomain proapoptotic molecules BAK or BAX are required to initiate the mitochondrial pathway of apoptosis. How cells maintain the potentially lethal proapoptotic effector BAK in a monomeric inactive conformation at mitochondria is unknown. In viable cells, we found BAK complexed with mitochondrial outer-membrane protein VDAC2, a VDAC isoform present in low abundance that interacts specifically with the inactive conformer of BAK. Cells deficient in VDAC2, but not cells lacking the more abundant VDAC1, exhibited enhanced BAK oligomerization and were more susceptible to apoptotic death. Conversely, overexpression of VDAC2 selectively prevented BAK activation and inhibited the mitochondrial apoptotic pathway. Death signals activate "BH3-only" molecules such as tBID, BIM, or BAD, which displace VDAC2 from BAK, enabling homo-oligomerization of BAK and apoptosis. Thus, VDAC2, an isoform restricted to mammals, regulates the activity of BAK and provides a connection between mitochondrial physiology and the core apoptotic pathway. 相似文献
240.