► Runoff was reduced by 37% by the prairie strips compared to 100% row crop. ► 10% prairie strategically incorporated into watersheds enough to reduce runoff. ► Buffer effectiveness increased along ...the years. ► Greater runoff reductions in spring–fall by prairie strips compared to 100% crops.
Intensively managed annual cropping systems have produced high crop yields but have often produced significant ecosystem services alteration, in particular hydrologic regulation loss. Reconversion of annual agricultural systems to perennial vegetation can lead to hydrologic function restoration, but its effect is still not well understood. Therefore, our objective was to assess the effects of strategic introduction of different amounts and location of native prairie vegetation (NPV) within agricultural landscapes on hydrological regulation. The study was conducted in Iowa (USA), and consisted of a fully balanced, replicated, incomplete block design whereby 12 zero-order ephemeral flow watersheds received four treatments consisting of varying proportions (0%, 10%, and 20%) of prairie vegetation located in different watershed positions (footslope vs. contour strips). Runoff volume and rate were measured from 2008 to 2010 (April–October) with an H-Flume installed in each catchment, and automated ISCO samplers.
Over the entire study period, we observed a total of 129 runoff events with an average runoff volume reduction of 37% based on the three treatments with NPV compared to watersheds with row crops. We observed a progressively greater reduction across the 3years of the study as the perennial strips became established with the greatest differences among treatments occurring in 2010. The differences among the watersheds were attributed mainly to NPV amount and position, with the 10% NPV at footslope treatment having the greatest runoff reduction probably because the portion of NPV filter strip that actually contacted watershed runoff was greater with the 10% NPV at footslope. We observed greater reductions in runoff in spring and fall likely because perennial prairie plants were active and crops were absent or not fully established. High antecedent soil moisture sometimes led to little benefit of the NPV treatments but in general the NPV treatments were effective during both small and large events. We conclude that, small amounts of NPV strategically incorporated into corn-soybean watersheds in the Midwest US can be used to effectively reduce runoff.
The presence of fruits provokes significant modifications in plant water relations and leaf gas exchange. The underlying processes driving these modifications are still uncertain and likely depend on ...the water deficit level. Our objective was to explain and track the modification of leaf-water relations by the presence of fruits and water deficit. With this aim, net photosynthesis rate (AN), stomatal conductance (gs), leaf osmotic potential (Ψπ), leaf soluble sugars and daily changes in a variable related to leaf turgor (leaf patch pressure) were measured in olive trees with and without fruits at the same time, under well-watered (WW) and water stress (WS) conditions. Leaf gas exchange was increased by the presence of fruits, this effect being observed mainly in WW trees, likely because under severe water stress, the dominant process is the response of the plant to the water stress and the presence of fruits has less impact on the leaf gas exchange. Ψπ was also higher for WW trees with fruits than for WW trees without fruits. Moreover, leaves from trees without fruits presented higher concentrations of soluble sugars and starch than leaves from trees with fruits for both WW and WS, these differences matching those found in Ψπ. Thus, the sugar accumulation would have had a dual effect because on one hand, it decreased Ψπ, and on the other hand, it would have downregulated AN, and finally gs in WW trees. Interestingly, the modification of Ψπ by the presence of fruits affected turgor in WW trees, the change in which can be identified with leaf turgor sensors. We conclude that plant water relationships and leaf gas exchange are modified by the presence of fruits through their effect on the export of sugars from leaves to fruits. The possibility of automatically identifying the onset of sugar demand by the fruit through the use of sensors, in addition to the water stress produced by soil water deficit and atmosphere drought, could be of great help for fruit orchard management in the future.
There is a controversy regarding when it is appropriate to apply the irrigation restriction in almond trees (Prunus dulcis Mill.) to save water without penalizing yield. We hypothesized that knowing ...when plants demand fewer photoassimilates would be a good indicator of less sensitivity of the crop to water deficit. One parameter that defines the photosynthetic capacity is the triose phosphate utilization (TPU). Due to its connection to the export of sugars from the leaves to other sink organs, it is a good candidate for being such an indicator. The objective was to analyze the seasonal evolution of the photosynthetic capacity of three almond cultivars (cvs Guara, Marta and Lauranne) subjected to water stress during vegetative, kernel-filling and postharvest stages. Two sustained deficit irrigation (SDI) treatments (SDI75 and SDI65 with water reductions of 25 and 35%, respectively) and a control treatment (FI) consisting of fully irrigated trees were applied. The response of curves AN-Ci was analyzed to assess the maximum carboxylation rate (Vcmax), maximum rate of electron transport (Jmax), TPU and mesophyll conductance to CO2. In addition, leaf water potential and yield were measured. Our experimental findings showed any significant differences in the variables analyzed among cultivars and irrigation treatments. However, consistent differences arose when the results were compared among the phenological stages. During the kernel-filling and the postharvest stages, a progressive limitation by TPU was measured, suggesting that the demand for photoassimilates by the plant was reduced. This result was supported by the correlation found between TPU and fruit growth rate. As a consequence, a downregulation in Jmax and Vcmax was also measured. This study confirms that the kernel-filling stage might be a good time to apply a reduction in the irrigation and suggests a method to detect the best moments to apply a regulated deficit irrigation in almond trees.
One of the main tools for including decision maker (DM) preferences in the multiobjective optimization (MO) literature is the use of reference points and achievement scalarizing functions A.P. ...Wierzbicki, The use of reference objectives in multiobjective optimization, in: G. Fandel, T. Gal (Eds.), Multiple-Criteria Decision Making Theory and Application, Springer-Verlag, New York, 1980, pp. 469–486.. The core idea in these approaches is converting the original MO problem into a single-objective optimization problem through the use of a scalarizing function based on a reference point. As a result, a single efficient point adapted to the DM’s preferences is obtained. However, a single solution can be less interesting than an approximation of the efficient set around this area, as stated for example by Deb in K. Deb, J. Sundar, N. Udaya Bhaskara Rao, S. Chaudhuri, Reference point based multiobjective optimization using evolutionary algorithms, International Journal of Computational Intelligence Research, 2(3) (2006) 273–286. In this paper, we propose a variation of the concept of Pareto dominance, called
g-dominance, which is based on the information included in a reference point and designed to be used with any MO evolutionary method or any MO metaheuristic. This concept will let us approximate the efficient set around the area of the most preferred point without using any scalarizing function. On the other hand, we will show how it can be easily used with any MO evolutionary method or any MO metaheuristic (just changing the dominance concept) and, to exemplify its use, we will show some results with some state-of-the-art-methods and some test problems.
Over the past century, agricultural landscapes worldwide have increasingly been managed for the primary purpose of producing food, while other diverse ecosystem services potentially available from ...these landscapes have often been undervalued and diminished. The incorporation of relatively small amounts of perennial vegetation in strategic locations within agricultural landscapes dominated by annual crops—or perennialization—creates an opportunity for enhancing the provision of a wide range of goods and services to society, such as water purification, hydrologic regulation, pollination services, control of pest and pathogen populations, diverse food and fuel products, and greater resilience to climate change and extreme disturbances, while at the same time improving the sustainability of food production. This paper synthesizes the current scientific theory and evidence for the role of perennial plants in balancing conservation with agricultural production, focusing on the Midwestern USA as a model system, while also drawing comparisons with other climatically diverse regions of the world. Particular emphasis is given to identifying promising opportunities for advancement and critical gaps in our knowledge related to purposefully integrating perennial vegetation into agroecosystems as a management tool for maximizing multiple benefits to society.
•Sap flux density (Js) correlated well with stomatal conductance (gs).•Profiles of Js were explained by gs of leaves with different light exposure and age.•Dynamics of Js were related to atmospheric ...and soil water deficit.•A method to estimate gs automatically in the field is presented.•The method proposed is a powerful tool as water stress indicator.
Water scarcity in semiarid regions of Europe threatens the sustainability of fruit tree orchards unless irrigation water is optimized and scheduled in deficit irrigation strategies. Stomatal conductance (gs) is one of the best indicators of plant water stress, since it is placed in the crossroad between water and CO2 fluxes at the leaf level. Unfortunately, it is not possible to measure gs automatically and continuously, which reduces its potential for irrigation scheduling. In this work we examined the use of sap flux density (Js) in the outer rings of the sapwood of olive trees as a surrogate of gs. The working hypothesis was that as olive trees are well-coupled to atmosphere because of their small leaves, the ratio of Js to air vapor pressure deficit (D) should correlate well with the dynamics of gs in the canopy. It was also expected that current year, sun exposed leaves were mainly connected to the outer rings of the sapwood, and the oldest, shaded leaves to the inner rings. This was tested by measuring gs in new, sun-exposed leaves vs gs in old, shaded leaves. Both hypotheses were contrasted and our results confirmed that gs can be estimated from Js/D (R2 of the relationships were always higher than 0.8). A wide range of estimated gs values (0.350–0.025molm−2s−1) were derived from Js measurements in an olive orchard under three different irrigation regimes. Results were satisfactory and open the possibility of applying this method to estimate gs and use it either as a reliable water stress indicator or in transpiration and photosynthesis models applied to fruit tree orchards under a wide range of water stress conditions.
Glycoconjugate vaccines provide effective prophylaxis against bacterial infections. To date, however, no commercial vaccine has been available in which the key carbohydrate antigens are produced ...synthetically. We describe the large-scale synthesis, pharmaceutical development, and clinical evaluation of a conjugate vaccine composed of a synthetic capsular polysaccharide antigen of Haemophilus influenzae type b (Hib). The vaccine was evaluated in clinical trials in Cuba and showed long-term protective antibody titers that compared favorably to licensed products prepared with the Hib polysaccharide extracted from bacteria. This demonstrates that access to synthetic complex carbohydrate-based vaccines is feasible and provides a basis for further development of similar approaches for other human pathogens.
Background
Access to drugs with hospital-restricted dispensation, such as those for patients with rheumatoid arthritis or psoriasis, is regulated by healthcare policy. These drugs have the greatest ...cost-effective impact on the healthcare system. This is why a model for Pharmaceutical Care based on follow-up teleconsultations was defined in our hospital to improve patient well-being.
Objective
To evaluate clinical changes on patients when our remote Pharmaceutical Care model is applied and describe the work carried out by pharmacists when applying it.
Setting
Pharmacy Department of a Hospital in Barcelona, Spain.
Method
Cross-sectional observational study of the remote Pharmaceutical Care model developed by Clinical Pharmacists. All patients diagnosed with psoriasis or rheumatoid arthritis who were receiving active treatment with Hospital/Specialist only drugs, during the period from May to December 2018, were included.
Main outcome measures
The corresponding healthcare activity was recorded and to determine the utility of the model, the clinical response to treatment of patients included in the study was recorded.
Results
The implementation of teleconsultation is statistically related to the biological treatment response of patients with psoriasis (
p
= 0.006) and rheumatoid arthritis (
p
= 0.019). In those patients the healthcare activity of calculating and/or recording clinical variables of effectiveness/safety is statistically associated to biological treatment response (65.62%
vs
35%,
p
= 0.015 and 73.14%
vs
53.26%,
p
= 0.003).
Conclusions
The implementation of the model described lends added value to traditional pharmacotherapeutic management of biological treatments in patients with rheumatoid arthritis and psoriasis since response is improved but patient well-being is not diminished.
•We proposed and tested an irrigation scheduling approach for olive orchards under regulated deficit irrigation.•Our approach is based on leaf turgor pressure related measurements made with ZIM ...probes.•We show evidence of our approach being suitable for olive trees of different age growing under a wide range of water conditions.•A comparison with the crop coefficient approach shows that our approach led to greater water savings for the same crop performance.•Our approach is suitable for commercial orchards and users with low training.
Regulated deficit irrigation (RDI) has been proposed as one of the most promising irrigation strategies for hedgerow fruit orchards with high plant densities. Scheduling a RDI strategy, however, is highly demanding, since the targeted water savings must be achieved at the same time that episodes of excessive water stress are avoided when the crop is most sensitive to drought. Here we tested an approach to schedule a RDI strategy supplying 45% of the crop irrigation needs, specially designed for hedgerow olive orchards. Our approach is based on the use of a water stress indicator derived from the shape of the daily curves recorded with ZIM sensors, which are related to the leaf turgor pressure. We worked in a mature, fully productive ‘Arbequina’ olive orchard with 1667 trees ha−1, under both a daily irrigated (FI) treatment and the mentioned RDI strategy. We found that the relation between the shape of the curves and the tree water stress levels holds for olive trees of different age under a wide range of growing conditions. We were able to schedule irrigation just from the visual analysis of the curves derived from the ZIM outputs, without any further data processing. A comparison with the crop coefficient approach showed that, with our approach, we achieved greater water savings without affecting neither the trees water status nor the crop performance. Still, further studies are required to confirm whether empirical aspects of our approach are limiting and, if so, to derive suitable alternatives.
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