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991.
A simple model for chickpea development, growth and yield   总被引:1,自引:0,他引:1  
Chickpea (Cicer arietinum L.) yield is unstable and low in major producer countries. A robust crop model can assist in evaluation of possible genetic improvements and cultural management practices to improve yield. The objectives of this study were to develop and test a chickpea simulation model that could be used across a wide range of environments. This model simulates phenological development, leaf development and senescence, mass partitioning, plant nitrogen balance, yield formation and soil water balance. Responses of crop processes to environmental factors of solar radiation, photoperiod, temperature, nitrogen and water availability, and genotype differences were included in the model. The model uses a daily time step and readily available weather and soil information. The model was tested using independent data from a wide range of growth and environmental conditions. In most cases, simulated grain yield were similar to observed yield (ranging from 20 to 379 g m−2) with a root mean square root of 26 g m−2 (15% of average measured yield). It was concluded that the model generality, i.e., constant parameters for genotypes across locations, and applicability to a wide range of environmental conditions factors made this model especially useful.  相似文献   
992.
Crude dihydroxystearic acid was prepared from palm based oleic acid and was then solvent purified with isopropyl alcohol in a custom fabricated simultaneous batch crystallizer unit. The crystallized dihydroxystearic acid was a functional ingredient that acted as multipurpose intermediate for synthesis of various fine chemicals, cosmetics and personal care products. The effects of solvent quantity and concentration on particle size distribution, crystal habit and morphology, and resultant crystal purity were studied. The crystals were purer but smaller and the span of the distribution curve was wider at higher solvent quantity and concentration. Through scanning electron microscopy and X-ray diffraction, it was observed that the crystals agglomerated into plate-like (flaky) habit with triclinic crystal structure. Solvent crystallization with 80% IPA at 20 °C and solute:solvent ratio of 1.0:1.0 was the most optimized and efficient, producing β-DHSA crystals that has high resistance against fat exudation during vacuum filtration process.  相似文献   
993.
The anesthetic activities of the essential oils (EOs) of Hesperozygis ringens (EOHR) and Lippia alba (EOLA) and their effects in silver catfish (Rhamdia quelen) after anesthesia and recovery were investigated. Fish (32.19 ± 1.24 g) were submitted to one of the following treatments for each EO: basal group, control, or anesthesia (150, 300, or 450 μL L?1 EO). After that the anesthesia was induced or simulated and the biometric measurements were completed, fish were transferred to anesthetic-free aquaria to allow for recovery. Fish were sampled at 0, 15, 30, 60, and 240 min after recovery. At time 0 of recovery, the ventilatory rate was lower in the groups anesthetized with either EO. In comparison with the basal group, control fish showed an increase in plasma glucose, aspartate aminotransferase (AST), and Na+ levels and a reduction in Na+/K+-ATPase activity at 0 min of recovery. Plasma levels of ammonia and Na+ were lower in the fish anesthetized with EOLA (450 μL L?1) and EOHR (all concentrations), respectively, than in the control fish. Additionally, lactate, AST, alanine aminotransferase, K+ plasma levels, and gill Na+/K+-ATPase and H+-ATPase activities were higher in the fish anesthetized with either EOHR or EOLA than in the control fish. The EOs promoted slight changes in silver catfish that enabled both an adaptive response and the recovery of most of the measured parameters after 240 min regardless of concentration or EO that was used. These findings support the use of EOHR and EOLA as anesthetics for fish.  相似文献   
994.
ABSTRACT

Among potential components to construct Technosols for urban greening purposes, the commercially available geogenic coarse porous materials (CPMs) are mainly used in practice because of their high porosity. However, the knowledge of the hydraulic behavior of CPMs as well as of their mixtures with other substrates is limited, provoking their suboptimal usage. Therefore, we determined the water retention characteristics, including the available water capacity (AWC) of six geogenic CPMs: porlith, expanded shale, expanded clay, tuff, pumice, and lava. In order to obtain the water retention characteristics of the CPMs as well as of their mixture with sand (1:4 per volume), the following methods adapted from soil physics were applied over a wide range of pressure heads: Equi-pF apparatus, ceramic tension plates, pressure plate extractors, WP4C apparatus, and water vapor adsorption. The results were used to parametrize the modified Kosugi model (using SHYPFIT 2.0). Porlith and tuff have the highest AWC (0.37 m3 m?3 and 0.17 m3 m?3, respectively) and are the only ones which can be recommended as effective water-retaining materials. Further materials exhibit an AWC less than 0.10 m3 m?3. The CPMs exhibit a bimodal pore size distribution, which can be well described by the applied model, except for pumice and expanded shale. The mixtures present overall low AWCs up to 0.07 m3 m?3, with the pure sand having less than 0.03 m3 m?3. For practical application a quite high ratio of CPM is needed, and the mixing material must be adapted to the hydraulic properties of the CPMs. The water inside the CPMs may be easily available for plant roots able to penetrate in the CPMs’ coarse pores.  相似文献   
995.

Key message

The diversity of forest management systems and the contrasted competition level treatments applied make the experimental networks of the GIS Coop, a nationwide testing program in the field of emerging forestry topics within the framework of the ongoing global changes.

Context

To understand the dynamics of forest management systems and build adapted growth models for new forestry practices, long-term experiment networks remain more crucial than ever.

Aims

Two principles are at the basis of the experimental design of the networks of the Scientific Interest Group Cooperative for data on forest tree and stand growth (GIS Coop): contrasted and extreme silvicultural treatments in diverse pedoclimatic contexts.

Methods

Various forest management systems are under study: regular and even-aged stands of Douglas fir, sessile and pedunculate oaks, Maritime and Laricio pines, mixed stands of sessile oak, European silver fir, and Douglas fir combined with other species. Highly contrasted stand density regimes, from open growth to self-thinning, are formalized quantitatively.

Results

One hundred and eighty-five sites representing a total of 1206 plots have been set up in the last 20 years, where trees are measured regularly (every 3 to 10 years). The major outputs of these networks for research and management are the calibration/validation of growth and yield models and the drawing up of forest management guides.

Conclusion

The GIS Coop adapts its networks so that they can contribute to develop growth models that explicitly integrate pedoclimatic factors and thus also contribute to research on the sustainability of ecosystems under environmental and socio-economic changes.
  相似文献   
996.

Key message

Static site indices determined from stands’ top height are derived from different forest inventory sources with height and age information and thus enable comparisons and modeling of a species’ productivity encompassing large environmental gradients.

Context

Estimating forest site productivity under changing climate requires models that cover a wide range of site conditions. To exploit different inventory sources, we need harmonized measures and procedures for the productive potential. Static site indices (SI) appear to be a good choice.

Aims

We propose a method to derive static site indices for different inventory designs and apply it to six tree species of the German and French National Forest Inventory (NFI). For Norway spruce and European beech, the climate dependency of SI is modeled in order to estimate trends in productivity due to climate change.

Methods

Height and age measures are determined from the top diameters of a species at a given site. The SI is determined for a reference age of 100 years.

Results

The top height proves as a stable height measure that can be derived harmoniously from German and French NFI. The boundaries of the age-height frame are well described by the Chapman-Richards function. For spruce and beech, generalized additive models of the SI against simple climate variables lead to stable and plausible model behavior.

Conclusion

The introduced methodology permits a harmonized quantification of forest site productivity by static site indices. Predicting productivity in dependence on climate illustrates the benefits of combined datasets.
  相似文献   
997.
Drosophila suzukii, a vinegar fly originated from Southeast Asia, has recently invaded western countries, and it has been recognized as an important threat of a wide variety of several commercial soft fruits. This review summarizes the current information about the biology and dispersal of D. suzukii and discusses the current status and prospects of control methods for the management of this pest. We highlight current knowledge and ongoing research on innovative environmental-friendly control methods with emphasis on the sterile insect technique (SIT) and the incompatible insect technique (IIT). SIT has been successfully used for the containment, suppression or even eradication of populations of insect pests. IIT has been proposed as a stand-alone tool or in conjunction with SIT for insect pest control. The principles of SIT and IIT are reviewed, and the potential value of each approach in the management of D. suzukii is analyzed. We thoroughly address the challenges of SIT and IIT, and we propose the use of SIT as a component of an area-wide integrated pest management approach to suppress D. suzukii populations. As a contingency plan, we suggest a promising alternative avenue through the combination of these two techniques, SIT/IIT, which has been developed and is currently being tested in open-field trials against Aedes mosquito populations. All the potential limiting factors that may render these methods ineffective, as well as the requirements that need to be fulfilled before their application, are discussed.  相似文献   
998.
Infratentorial tumors are relatively infrequent in dogs and a lack of data makes it difficult to offer prognostic information. Untreated, dogs with these neoplasms have shorter survival times than those with supratentorial tumors. The role of radiation therapy (RT) in the management of infratentorial tumors is poorly defined and tumoral/peritumoral swelling in this site is a potential cause of serious acute side effects. The aim of this retrospective, cohort study was to describe cases of infratentorial tumors treated with fractionated three‐dimensional conformal RT (3D CRT) and glucocorticoids (GC), and compare outcomes and survival with dogs affected by tumors in the same location that received GC alone. Thirty patients with a MRI diagnosis of infratentorial tumors were recruited (15 received RT and GC and 15 GC alone). None had mentation changes at presentation. For both groups, MRI and medical records were reviewed; and factors associated with survival were evaluated with Kaplan–Meier product limit survival and Cox regression analysis. Overall median survival time (MST) was 294 days (95% CI 42–545). The MST in the RT group was 756 days (95% CI 209–1302) vs. 89 days (95% CI 34.7–143.3 days) for those dogs treated palliatively with GC alone. This difference was statistically significant (P = 0.001). No other factors (including neurological signs, MRI features, tumor volume and total RT dose) were statistically associated with survival in the RT group. This study suggests that 3D CRT offers a survival advantage for dogs with infratentorial tumors compared to GC alone, and significant complications are uncommon.  相似文献   
999.
1000.
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