215 research outputs found

    Technical Note: Design of a large variable temperature chamber for heat stress studies in rabbits

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    [EN] One of the major constraint factors for rabbit production consists of the environmental conditions and especially high temperatures that negatively affect reproduction and growth performance. For this reason, several studies have addressed the effects of heat stress and possible solutions to alleviate its impact on rabbit performance. This article describes the design and operating features of a large temperature chamber (13x4.7x3.1 m) configured to house 42 rabbits. The probes consisted of temperature sensor model DS2438 and humidity sensor model HIH-5031. The system was controlled by an Arduino platform programmed by its Integrated Development Environment (IDE) software. The system takes a decision every minute: it connects the heating if the temperature is lower than programmed and connects exhaust fans if the temperature is over the programmed setting. To renew the indoor air, every 5 min the system switches off the heating and switches on the exhaust fans for 15 sec. Two experiments (with and without animals) were carried out to test the temperature control accuracy. Firstly, without animals, two tests were performed: (i) adjusting the temperature of the climatic chamber to the control house temperature plus 10ÂșC and (ii) based on daily minimum (32ÂșC) and maximum (37ÂșC) temperatures. Secondly, with animals, does were maintained (i) between a daily minimum (32ÂșC) and maximum (37ÂșC) for 48 h and (ii) between a daily minimum (25ÂșC) and maximum (35ÂșC) temperatures for 105 d. Mortality rates were noted in both tests. The results of comparing the measured temperature deviation from programmed temperature reported a coefficient of determination of 0.9850 and 0.9947, for plus 10ÂșC and 32-37ÂșC curves, respectively. In the animal tests, the determination coefficients were 0.9926 and 0.9928 for programmed curve in the range of 32 to 37ÂșC and 0.9859, 0.9900 and 0.9901 for programmed curve in the range of 25 to 35ÂșC. Survival of females in the temperature chamber was as expected for reproductive rabbit does: 100 and 82% in the 2 and 105 d trials, respectively. Results indicate that the chamber provided precise temperature control for the development of heat stress studies in rabbits.This work was supported by the Spanish Research Project (CICYT AGL2008-03274) and the Spanish "Ministry of Science and Innovation" HAR2010-21944-C02-01 and HAR2010-21944-C02-02.GarcĂ­a Diego, FJ.; Pascual AmorĂłs, JJ.; Marco JimĂ©nez, F. (2011). Technical Note: Design of a large variable temperature chamber for heat stress studies in rabbits. World Rabbit Science. 19(4). https://doi.org/10.4995/wrs.2011.938SWORD19

    Effect of UV-Absorbing Nets on the Performance of the Aphid Predator Sphaerophoria Rueppellii (Diptera: Syrphidae)

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    Photoselective nets have proven to be effective for aphid pest control as they limit their dispersal ability. However, little is known on the impact of such nets on natural enemies of aphids. In this work, we study the effect of UV-absorbing nets on the syrphid fly Sphaerophoria rueppellii Wiedemann (Diptera: Syrphidae), a commercially available aphid biocontrol agent in Mediterranean horticultural crops. First, we released mature syrphid adults and evaluated density and dispersal of the resulting immatures in a turnip crop grown under either UV-blocking (Bionet) or standard net. Second, we assessed, under controlled conditions, the impact of UV radiation on fitness-related parameters, and on flight behavior of S. rueppellii adults. Results showed that, while syprhid immature density was higher, their dispersion was reduced under Bionet. UV-absorbing nets are known to influence the dispersion pattern of aphids, which may have indirectly conditioned the distribution of their predator S. rueppellii. On the other hand, the type of net had no influence on the performance of adults. We conclude that the use of photoselective nets and the release of syrphid predators such S. rueppellii are compatible strategies to be used in IPM aphid-control programs.This research was funded by the Spanish Ministry of Science and Education (AGL2005-01449/AGR project). R.A.J was supported by JAE Predoc CSIC scholarship (JAEPre_08_00457)

    Coverage and invariance for the biological control of pests in mediterranean greenhouses

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    A major problem related to the treatment of ecosystems is that they have no available mathematical formalization. This implies that many of their properties are not presented as short, rigorous modalities, but rather as long expressions which, from a biological standpoint, totally capture the significance of the property, but which have the disadvantage of not being sufficiently manageable, from a mathematical standpoint. The interpretation of ecosystems through networks allows us to employ the concepts of coverage and invariance alongside other related concepts. The latter will allow us to present the two most important relations in an ecosystem – predator–prey and competition – in a different way. Biological control, defined as “the use of living organisms, their resources or their products to prevent or reduce loss or damage caused by pests”, is now considered the environmentally safest and most economically advantageous method of pest control (van Lenteren, 2011). A guild includes all those organisms that share a common food resource (Polis et al., 1989), which in the context of biological control means all the natural enemies of a given pest. There are several types of intraguild interactions, but the one that has received most research attention is intraguild predation, which occurs when two organisms share the same prey while at the same time participating in some kind of trophic interaction. However, this is not the only intraguild relationship possible, and studies are now being conducted on others, such as oviposition deterrence. In this article, we apply the developed concepts of structural functions, coverage, invariant sets, etc. (Lloret et al., 1998, Esteve and Lloret, 2006a, Esteve and Lloret, 2006b and Esteve and Lloret, 2007) to a tritrophic system that includes aphids, one of the most damaging pests and a current bottleneck for the success of biological control in Mediterranean greenhouses

    A new strategy to maximize organic matter valorization in municipalities: combination of urban wastewater with kitchen food waste and its treatment with AnMBR technology

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    [EN] The aim of this study was to evaluate the feasibility of treating the kitchen food waste (FW) jointly with urban wastewater (WW) in a wastewater treatment plant (WWTP) by anaerobic membrane technology (AnMBR). The experience was carried out in six different periods in an AnMBR pilot-plant for a total of 536 days, varying the SRT, HRT and the food waste penetration factor (PF) of food waste disposers. The results showed increased methane production of up to 190% at 70 days SRT, 24 hours HRT and 80% PF, compared with WW treatment only. FW COD and biodegradability were higher than in WW, so that the incorporation of FW into the treatment increases the organic load and the methane production and reduces sludge production (0.142 vs 0.614 kg VSSkg removed COD-1, at 70 days SRT, 24 hours HRT and 80% PF, as compared to WW treatment only).This research work was possible thanks to financial support from Generalitat Valenciana (project PROMETE0/2012/029) which is gratefully acknowledged. Besides, support from FCC Aqualia participation in INNPRONTA 2011 IISIS IPT-20111023 project (partially funded by The Centre for Industrial Technological Development (CDTI) and from the Spanish Ministry of Economy and Competitiveness) is gratefully acknowledged.Moñino Amorós, P.; Aguado García, D.; Barat, R.; Jiménez, E.; Giménez, J.; Seco, A.; Ferrer, J. (2017). A new strategy to maximize organic matter valorization in municipalities: combination of urban wastewater with kitchen food waste and its treatment with AnMBR technology. Waste Management. 62:274-289. https://doi.org/10.1016/j.wasman.2017.02.006S2742896

    Trace Elements Distribution in Red Soils under Semiarid Mediterranean Environment

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    This study states the potential trace elements (TE’s) content of red soils located at the centre region of Spain, characterized by low rainfall and slight acidity over prolonged weathering periods. For this purpose, three soil profiles from a catena were described, sampled and analyzed. The most notable characteristics are the low organic matter content and the predominantly acidic pH. Illite and kaolinite are the predominant clay minerals. The fertility of the soils is sufficient to provide most of the nutrients required, with very suitable potassium levels. The geochemical characters of this soil are: only few elements remain almost invariable across the profiles and over time, however the majority of them were directly linked with the clay content. These soils are characterized by relatively low levels of some trace elements such as Sr (64.35 mg?kg–1), Ba (303.67 mg?kg–1) and Sc (13.14 mg?kg–1); high levels of other trace elements such as V (103.92 mg?kg–1), Cr (79.9 mg?kg–1), Cu (15.18 mg?kg–1), Hf (10.26 mg?kg–1), Ni (38 mg?kg–1) and Zr (337 mg?kg–1); while the levels for rare earth elements (REE’s) such as La (48.36 mg?kg–1), Ce (95.07 mg?kg–1), Th (13.33 mg?kg–1) and Nd (42.65 mg?kg–1) are significantly high. The distribution of mayor and trace elements was directly re- lated to weathering processes, parent material and anthropogenic activities

    Contents and Spatial Distribution of Arsenic in Vineyard Soils in Mediterranean Environment

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    This study presents the contents and spatial distribution of arsenic (As) in vineyard soils from the Valdepeñas Protected Designation Origin (PDO) in central Spain. As content varies within the 108.40–0.03 mg·kg−1 range in surface horizons, and within 151.00–0.03 mg·kg−1 in subsurface horizons. The mean value of both horizons is similar: 4.25 and 4.88 mg·kg−1, respectively. Based on optimal spatial interpolation, the spatial distribution of As in soils was mapped by the IDV method. A simple data and map analysis suggests that pedogeogenic sources are the main sources for As (the As distribution tends to match the lithology and soil types), which indicates minor anthropogenic sources, mainly by agricultural sector activities. Only a high As concentration appears in the NE area, where sporadic moderate contamination is estimated based on Dutch criteria. The data obtained from the study area provide a broader view of the concentration, distribution, enrichment, sources, and the potential environmental contamination by As in the vineyard soils of this large winegrowing zone. The assessment of the results indicates that As does not afect agriculture (vineyards) in the study area because its concentrations are low in the soil types used by agriculture. These data can be employed as a guide to learn the range of values in vineyard soils in the European Mediterranean Region that are relatively unpolluted from industrial sources to make comparisons to more polluted areasOpen Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This research was supported by the Valdepeñas Protected Designation of Origin (PDO) “DenominaciĂłn de Origen Valdepeñas AsociaciĂłn Interprofesional” (project number UCTR180065

    Understanding the quality of local vineyard soils in distinct viticultural areas: a case study in Alcubillas (La Mancha, central Spain)

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    The essential features of the soils of a pilot zone in La Mancha (Central Spain), namely the Alcubillas municipability, have been characterized. The soil properties that may contribute to a better understanding of the impact of soil on grape production have also, been evaluated. For this, several soil profiles have been described and analyzed and the profiles have been mapped. The soils are mainly Entisols, Inceptisols and Alfisols, with their evolution controlled by the action of a xerophytic Mediterranean climate. Most of these soils have a loamy clay texture, with medium clay contents and sufficient nutrient contents (despite the low content in organic matter 1.39% and 1.04%, and the high concentrations of calcium carbonate 23.7% and 26.9% in the surface and subsurface horizons, respectively). Drainage problems were not observed and it can therefore be stated that the Alcubillas vineyards are based on a ‘terroir’ term for the production of high quality grapes. In general, the soils are not subjected to treatments to control possible diseases or pests and we have therefore postulated that the soils represent the ideal scenario to establish a distinctive zone and for the increasingly valued ecological and natural viticultureThis research was funded by “DenominaciĂłn de origen Valdepeñas” (denomination of origen), grant number UCTR18006

    Characteristics of vineyard soils derived from Plio-Quaternary landforms (raña or rañizo) in southern Europe

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    Soil is an essential component in viticulture. The study reported here concerns the assessment of the morphology chemical and physicochemical features of typical, well-developed and representative evolved Mediterranean soils near Anchuras (Spain, southern Europe), a site with soils that developed on old landforms (Plio-Quaternary) called ‘raña’ and/or ‘rañizo’. The soils under study were described and sampled by conducting soil surveys. Selected soil properties, such as texture, bulk density, pH, electrical conductivity (EC), cation exchange capacity (CEC) and contents of organic matter, nutrients, etc., were analysed using standard procedures. The results showed that these landscape surfaces were, linked with specific soil properties such as low pH (from 4.4 to 5.3) and EC (from 0.15 to 0.02 dSm 1 ), clay contents (20.1%–48.8%), high CEC (26–39 cmol/kg), and low base saturation values (from 11.2% to 17.2%), and have an adequate and singular pedological potential in relation to the ‘terroir’ or ‘terron’ concepts that meet suitability criteria. Furthermore, the information provided by this study, fundamentally through the weathering indices, supports the role of soil-forming factors and their influence on soil properties. In addition, as these landforms and underlying materials have abundant and extensive rock fragments, the role of these soils in the context of vineyard growth and development has been investigatedThis research was supported by the Winerin Eldoze (Project number UCTR180065

    Quantitative characterization of multicomponent polymers by sample-controlled thermal analysis

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    This paper explores the potential of sample-controlled thermal analysis (SCTA) in order to perform compositional analysis of multicomponent polymeric materials by means of thermogravimetric experiments. In SCTA experiments, the response of the sample to the temperature determines the evolution of the temperature by means of a feedback system; thus, what is controlled is not the temperature-time profile, as in conventional analysis, but rather the evolution of the reaction rate with time. The higher resolving power provided by the technique has been used for determining the composition of polymer blends composed of polyvinyl chloride (PVC) and different commercial plasticizers, a system where the individual components have very similar thermal stabilities, thereby rendering useless thermogravimetric experiments run under conventional conditions. Different SCTA procedures, such as constant rate thermal analysis (CRTA), which has received special attention, and high-resolution and stepwise isothermal analysis have been tested, and the results obtained have been compared with linear heating rate technique. It has been proven that CRTA can be used to effectively determine the exact composition of the blend.Junta de AndalucĂ­a TEP-03002Ministerio de Ciencia e InnovaciĂłn MAT 2008- 06619/MA

    Soil and leaf mineral element contents in mediterranean vineyards: bioaccumulation and potential soil pollution

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    The study reported here concerns the geochemical distributions of macro- and trace elements (including potentially toxic elements, PTEs) in the vineyard soils of Alcubillas, which is one of the oldest, albeit not world-renowned, wine-growing areas in La Mancha (Central Spain). Soil and leaf samples were analyzed by X-ray fluorescence spectrometry to ascertain the levels of various elements in the soil and the plant. The potential toxicity of the elements was assessed with regard to the development of the vineyard. Despite the fact that fertilizers and pesticides are employed in the vineyards in this area, the results showed that the levels of trace elements in the soil samples did not exceed the reference values according the pedogeochemical values for the region and Spain. This finding suggests that the study area is not polluted, and therefore, there are hardly any traces of anthropogenic contamination. The Biological Absorption Coefficient (BAC) was calculated to assess the assimilation of various elements from the soil to the leaves, and differences were found in the element absorption capacity of the vines. Some elements were not taken up by Vitis vinifera despite elements like Zr and Rb being present in relatively high concentrations in the soil. The production in these soils does not represent a threat to human health or the ecosystem, because the farmers in this area are extremely careful to preserve the environment and they only farm to achieve moderate yields of grapes per hectar
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