Non-papilionate and actinomorphic flowers have evolved independently in Papilionoideae, and few ontogeny studies are available about them. The objective of the present study was to better understand ...the ontogenetic processes that result in papilionate and non-papilionate flowers in a sister group of the Pterocarpus clade. Inflorescences, flower buds and flowers of
Discolobium pulchellum
and
Riedeliella graciliflora
were analyzed by scanning electron microscopy, light microscopy and histochemistry of the secretory structures of floral organs. The differentiation of the petals is initiated by the petal standard followed by the keel petals and finally by the wing petals in
Discolobium
, in contrast to a unidirectional development of the petals in the corolla of
Riedeliella
. The order of sepals and antesepalous stamen is unidirectional in
D. pulchellum
and modified unidirectional in
R. graciliflora
; however, the order of petal and antepetalous stamen initiation, stamen symmetry and early appearance of carpel are similar in both species. Hypanthium and floral nectary are present only in
D. pulchellum
and colleters in
R. graciliflora
. Glandular trichomes and idioblasts are present in both species. The presence of secretory structures is possibly related to the protection against herbivores, to pollination and pollinator’s attraction since different secondary compounds are present in reproductive structures. The development of the actinomorphic corolla of
Riedeliella graciliflora
has no similarity in terms of floral development to the other representatives of actinomorphic symmetry in Papilionoideae.
Nitrogen (N) fertilization in durum wheat has traditionally been managed based on yield goals without considering temporal and spatial variability of yield potential related to changes in soil ...properties, weather and crop response to fertilization. In fact, this approach may lead to inefficient N use by the crop, resulting in both economic losses and environmental issues. To overcome these drawbacks, several optical-oriented, site-specific management systems have been developed to consider the effect of the aforementioned sources of variability and modulate N applications to the actual crop nutrient status and requirements. In this study, a novel approach that integrates proximal sensing, seasonal weather forecasts and crop modelling to manage site-specific N fertilization in durum wheat is proposed. This approach is based on four successive steps: (1) optimal N supply is estimated by means of a crop model fed with a mix of observed and forecast weather data; (2) actual crop N uptake is estimated using proximal sensing; (3) N prescription maps are created merging crop model and proximal sensing information; (4) N-Variable Rate Application (N-VRA). The aforementioned approach was implemented in a 13.6-ha field characterized by large soil variability in texture and organic matter content. Results indicated that the system was able to capture spatial variability in crop N uptake and manage N distribution through N-VRA leading to a substantial reduction of the spatial variability in yield and protein content while reducing the total amount of N supplied compared to uniform treatments. However, further advances are necessary to improve model performances.
Two-bladed rotors are emerging as a viable alternative to classic three-bladed ones for driving down the cost of energy of large sized wind turbines. By eliminating a blade one could easily reduce ...the cost of the rotor. However, design challenges arise due to the reduced power output and the resonance typically occurring between the frequency of the tower and the two-per-revolution. In this work, we perform a dedicated design of a two-bladed configuration for a 10 MW wind turbine: the solution is upwind and equipped with a teeter hinge at the hub in order to alleviate the loads on the fixed infrastructure. The rotor and the tower are then optimized by using a holistic design algorithm, and a complete technical and economic assessment of the optimal design is conducted against a reference three-bladed one in order to compare the main performance including loads, energy yielding and the cost of energy.
We use the capabilities of a multi-disciplinary design tool to provide a definition of a 20 MW wind turbine. Starting from an aero-elastic model obtained through a classic scaling procedure, we ...conduct an aero-structural optimization of the rotor through a staged redesign process, in which we optimize primary characteristics of the rotor including the blade shape, the solidity and a certain amount of native structural tailoring. The process is based on a series of parametric analysis, in order to assess the impact of a variation of macro design parameters on the fundamental performance of the turbine. The redesign activity shows remarkable advantages in terms of blade mass reduction and load alleviation, highlighting directions for the development and optimization of very large rotors.
Several remote sensing-based methods have been developed to apply site-specific nitrogen (N) fertilization in crops. They consider spatial and temporal variability in the soil-plant-atmosphere ...continuum to modulate N applications to the actual crop nutrient status and requirements. However, deriving fertilizer N recommendations exclusively from remote proximal and remote sensing data can lead to substantial inaccuracies and new, more complex approaches are needed.
Therefore, this study presents an improved approach that integrates crop modelling, proximal sensing and forecasts weather data to manage site-specific N fertilization in winter wheat. This improved approach is based on four successive steps: (1)
optimal
N supply is estimated through the DSSAT crop model informed with a combination of observed and forecast weather data; (2)
actual
crop N uptake is estimated using proximal sensing; (3) N prescription maps are created merging crop model and proximal sensing information, considering also the contribution of the soil N mineralisation; (4) N-Variable Rate Application (N-VRA) is implemented in the field. A VRA method based on DSSAT fed with historical weather data and a business-as- usual uniform fertilization were also compared.
The methods were implemented in a 23.4 ha field in Northern Italy, cropped to wheat and characterized by large soil variability in texture and organic matter content. Results indicated that the model-based approaches consistently led to higher yields, agronomic efficiencies and gross margins than the uniform N application rate. Furthermore, the proximal sensing-based approach allowed capturing of the spatial variability in crop N uptake and led to a substantial reduction of the spatial variability in yield and protein content. This study grounds the development of web-based software as a friendly tool to optimize the N variable rate application in winter cereals.
Variable rate fertilization and precision harvesting could increase the potential for meeting durum wheat quality standards. Field spatial distribution of yield and protein content, and their ...interactions with soil properties and N fertilization were evaluated in an experiment on durum wheat in North Italy in 2011 and 2012. Variable rate fertilization was adopted in three management zones (MZs) with increasing soil fertility, and a foliar N was applied at flowering to investigate differences in protein quantity and quality. During the crop cycle, changes in crop biomass and N status were monitored through NDVI measurement, and grain was sampled in each MZ and gluten proteins extracted at harvest. Spatial variability of yield and protein content was mainly driven by soil texture and base fertilization in both the years, while foliar fertilization was not efficient in enhancing grain protein content. Variable rate fertilization partially mitigated the weather impact; however, unpredictable weather conditions resulted in low N use efficiency. High N rates were confirmed to provide high protein levels and enhance gluten proteins technological quality, but with a risk for the environment. The marked spatial variability in grain quality in terms of total protein and gluten protein content, and the ratio between glutenin/gliadin and high and low-molecular weight glutenin sub-units, suggested the implementation of zone harvesting as a strategy to exploit the positive interaction between grain quality and soil fertility.
Abstract Background and aims Serum uric acid (SUA) is the end-product of purine metabolism in humans, and its levels often increase in subjects with metabolic syndrome (MetS). Despite several studies ...demonstrating a relationship between increased SUA levels and the prevalence of MetS, prospective data on SUA as a predictor of the incidence of MetS in the elderly are limited. Our aim was to conduct a prospective study on the association between SUA concentrations and the onset of MetS in an elderly Italian cohort. Methods and results This is a cohort study (Progetto Veneto Anziani; Pro.V.A.) involving community-dwelling subjects aged ≥65 years and followed up for a mean 4.4 years. We included 1128 participants (aged 74.7 ± 7.1 years) without MetS at the baseline. Gender-specific SUA groups according to the standard deviation (SD) from the mean were considered, taking the incidence of MetS as the main outcome. The mean SUA level was significantly higher in men than in women (5.4 ± 1.2 vs. 4.5 ± 1.2 mg/dl; p < 0.0001). Over the 4.4-year follow-up, 496 individuals developed MetS. After adjusting for potential confounders, Cox's regression analysis revealed no relationship between higher baseline SUA concentrations and the incidence of MetS in men or in the sample as whole, while women with SUA levels more than 1 SD above the mean (≥5.7 mg/dl) carried a 58% higher risk (95%CI: 1.03–2.40; p = 0.03) of being newly diagnosed with MetS during the follow-up. Conclusion High SUA levels significantly and independently predicted MetS in older women, but not in men, over a 4.4-year follow-up.
In this work, we investigate the impact of different wind farm control techniques on the structural design of a 10MW reference wind turbine. Active wake mixing and wake redirection have been recently ...proposed as a way to reduce wake-turbine interference in a wind farm and both show potential for improving the overall power production. However, such controllers modify the dynamic behaviour of the individual turbine, so that a thorough assessment of the resulting loads and displacements becomes necessary. In fact, as most wind turbines are designed according to international standards, one or more structural constraints are active on the final design, meaning that an increase of the sizing loads, or deflections, would make necessary to modify the structural layout. To investigate these aspects, we compare three redesigns of the same rotor: the first is equipped with a standard controller, while the second and the third integrate different wind farm controllers. All the solutions are optimized with our in-house design tool so that the three configurations emerge from the same design process. Results are then compared in terms of ultimate and fatigue loads, displacements and blade mass.
Agricultural soil roughness is pertinent to important agricultural phenomena, such as evaporation, infiltration or compression. Monitoring roughness variations would make possible the improvement of ...tillage operations. In the present work, implementation of the Microsoft Kinect™ RGB-depth camera for dynamic characterization of soil micro-relief is proposed and discussed. The metrological performance and the effect of the operating conditions on three-dimensional reconstruction was analyzed considering both laboratory tests on calibrated reference surfaces and field tests on different agricultural soil surfaces. Data set analysis was made on the basis of surface roughness parameters, as defined by ISO 25178 (2012) series: average roughness, root mean square roughness, skewness and kurtosis. Correlation between different tillage conditions and roughness parameters describing soil morphology was finally discussed.
Various factors, such as habitat availability, competition for space, predation, temperature, nutrient supplies, presence of waterfalls, flow variability and water quality, control the abundance, ...distribution and productivity of stream-dwelling organisms. Each of these factors can influence the response of the density of organisms to a specific environmental gradient, inflating variability and making difficult to understand the possible causal relationship. In our study, we used quantile regression mixed models and Akaike’s information criterion as an indicator of goodness to examine two different datasets, one belonging to Italy and one belonging to Finland, and to detect the limiting action of selected environmental variables. In the Italian dataset, we studied the relationships among five macroinvertebrate families and three physical habitat characteristics (water velocity, depth and substratum size); in the Finnish dataset the relationships between taxa richness and 16 environmental characteristics (chemical and physical). We found limiting relationships in both datasets and validated all of them on different datasets. These relationships are quantitative and can be used to predict the range of macroinvertebrate densities or taxa richness as a function of environmental characteristics. They can be a tool for management purposes, providing the basis for habitat-based models and for the development of ecological indices.
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