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201.
Santiago Bonachela Melchor Juan J. Jesús Casas Francisca Fuentes-Rodríguez Irene Gallego María Antonia Elorrieta 《Irrigation Science》2013,31(4):769-780
The influence of pond management on water quality for drip-irrigated crops was studied throughout a field survey and a mesocosm experiment. Water sources were pooled into two groups: ground or surface water (GW/SW) and recycled wastewater. Pond covering, which was limited to about a quarter of them, improved water quality by reducing phytoplankton biomass. However, biocide applications and pond dredging were ineffective at improving in-pond water quality. Dredging did not reduce the concentrations of planktonic chlorophyll a or total suspended solids (TSS) in GW/SW fed ponds, whereas biocide applications increased both parameters. Field and experimental data proved that the two predominant taxa of submerged aquatic vegetation (SAV) found in ponds (Potamogeton pectinatus and Chara spp.) improved water quality by increasing water oxygenation and decreasing chlorophyll a and TSS concentrations. Preserving SAV (especially Chara spp.) appears to be an environment-friendly, cost-effective and recommendable alternative strategy for irrigation pond management. 相似文献
202.
Caro MR Buendía AJ Del Rio L Ortega N Gallego MC Cuello F Navarro JA Sanchez J Salinas J 《Veterinary microbiology》2009,135(1-2):103-111
Chlamydophila (C.) abortus is an obligate intracellular bacterium able to colonize the placenta of several species of mammals, which may induce abortion in the last third of pregnancy. The infection affects mainly small ruminants resulting in major economic losses in farming industries worldwide. Furthermore, its zoonotic risk has been reported in pregnant farmers or abattoir workers. Mouse models have been widely used to study both the pathology of the disease and the role of immune cells in controlling infection. Moreover, this animal experimental model has been considered a useful tool to evaluate new vaccine candidates and adjuvants that could prevent abortion and reduce fetal death. Future studies using these models will provide and reveal information about the precise mechanisms in the immune response against C. abortus and will increase the knowledge about poorly understood issues such as chlamydial persistence. 相似文献
203.
204.
Pecoits E Konhauser KO Aubet NR Heaman LM Veroslavsky G Stern RA Gingras MK 《Science (New York, N.Y.)》2012,336(6089):1693-1696
Based on molecular clocks and biomarker studies, it is possible that bilaterian life emerged early in the Ediacaran, but at present, no fossils or trace fossils from this time have been reported. Here we report the discovery of the oldest bilaterian burrows in shallow-water glaciomarine sediments from the Tacuarí Formation, Uruguay. Uranium-lead dating of zircons in cross-cutting granite dykes constrains the age of these burrows to be at least 585 million years old. Their features indicate infaunal grazing activity by early eumetazoans. Active backfill within the burrow, an ability to wander upward and downward to exploit shallowly situated sedimentary laminae, and sinuous meandering suggest advanced behavioral adaptations. These findings unite the paleontological and molecular data pertaining to the evolution of bilaterians, and link bilaterian origins to the environmental changes that took place during the Neoproterozoic glaciations. 相似文献
205.
206.
Different management practices are commonly applied to increase pasture yield of Mediterranean open woodlands, but the consequences of increasing competition for soil resources with these practices on tree recruitment are still unknown. In a greenhouse study, belowground competition of Quercus suber L. seedlings growing together with natural (OakNP) or improved pasture (OakIP) was evaluated, and their root systems compared with those of seedlings growing in bare soil (OakBS). Two watering levels and two regimes of P2O5 fertilisation were also tested. Because of competition, the OakIP seedlings had their fine root mass density, coarse root length, and shoot mass reduced by up to 40, 36, and 39%, respectively, when compared to OakNP seedlings. OakNP and OakBS seedlings showed similar average root density parameters and shoot mass values, indicating that Q. suber seedlings growing with natural pasture is a low competitive system. High availability of water and phosphorus did not mitigate the strength of competition between herbaceous plants and oak seedlings, and favoured the pasture to the detriment of the trees. Our findings suggest that P2O5 fertilisation and irrigation practices performed to improve herbaceous productivity will negatively influence recruitment of Q. suber seedlings. 相似文献
207.
The aim of the study was to investigate changes in volumetric capnography (V(C)) variables during bronchoconstriction in dogs and compare it with total respiratory resistance (R(L)) measured with a Fleisch pneumotachograph. Six dogs were challenged with increasing concentrations of carbachol until obvious signs of bronchoconstriction were seen. All V(C) parameters were obtained before, directly after, 10 and 20 min after maximal bronchoconstriction. The slope of phase III (SIII) and airway and alveolar dead space parameters were significantly different from baseline directly after the challenge. The V(C) curve obtained a typical shape at the time of maximal bronchoconstriction and a trend to return to baseline shape was seen over time. A significant correlation was found for all aforementioned parameters with R(L). We conclude that the shape of the V(C) curve in combination with dead space calculation can be used to verify bronchoconstriction on a breath-to-breath basis. 相似文献
208.
Pablo F. Roncallo Gerardo L. Cervigni Carlos Jensen Rubén Miranda Alicia D. Carrera Marcelo Helguera Viviana Echenique 《Euphytica》2012,185(1):77-92
The aim of this work was to map quantitative trait loci (QTLs) associated with flour yellow color (Fb*) and yellow pigment
content (YPC) in durum wheat (Triticum turgidum L. var. durum). Additionally, QTLs affecting flour redness (Fa*) and brightness (FL*) color parameters were investigated. A population
of 93 RILs (UC1113 × Kofa) was evaluated in three locations of Argentina over 2 years. High heritability values (>94%) were
obtained for Fb* and YPC, whereas FL* and Fa* showed intermediate to high values. The main QTLs affecting Fb* and YPC overlapped
on chromosome arms 4AL (4AL.2), 6AL (6AL.2), 7AS, 7AL, 7BS (7BS.2) and 7BL (7BL.2). The 7BL.1 QTL included the Psy-B1 locus, but one additional linked QTL was detected. A novel minor QTL located on 7AS affected Fb*, with an epistatic effect
on YPC. An epistatic interaction occurred between the 7AL and 7BL.2 QTLs. The 4AL.2 QTL showed a strong effect on Fb* and
was involved in two digenic epistatic interactions. The 6AL.2 QTL explained most of the variation for Fb* and YPC. The main
QTLs affecting FL* and Fa* were located on 2BS and 7BL, respectively. These results confirm the complex inheritance of flour
color traits and open the possibility of developing perfect markers to improve pasta quality in Argentinean breeding programs. 相似文献
209.
Alejandra Pérez-Nava Josué D. Mota-Morales Zaira Y. García-Carvajal Sara E. Herrera-Rodríguez Gerardo Arrevillaga-Boni Cristy L. Azanza-Ricardo Milton O. Vazquez-Lepe J. Betzabe Gonzalez-Campos 《Fibers and Polymers》2018,19(1):156-169
Silver and gold nanoparticles were produced and embedded in poly(vinyl alcohol) (PVA) and chitosan (CTS) solutions by the photoreduction of metallic salt precursors triggered by direct sunlight irradiation, in which the polymers acted as reducing, dispersing and stabilizing agents. Sunlight photoreduction can be standardized using a constant UV index regardless of the season. This strategy was found to be an improvement over other common energy sources used to trigger the reduction of metal ions, including UV light irradiation and high-temperature reduction with mechanical stirring. The resulting PVA/metal nanoparticle and CTS/metal nanoparticle composite solutions were processed into thin films and nanofiber composites. In vitro testing of the cytotoxicity and biocompatibility demonstrates that the film composites are non-toxic and biocompatible with the HT-29 human colon cancer cell line. Promotion of HT-29 cell growth using our hybrid composites was observed, in contrast to other studies in which colloidal NPs were tested. Therefore, a sustainable approach for the onestep preparation of biocompatible polymer/metallic nanoparticle composites is reported. 相似文献
210.
J. Sánchez J. Sánchez-Cara E. Gallego 《European journal of plant pathology / European Foundation for Plant Pathology》2000,106(3):209-214
Ten types of plant baits were tested in the laboratory to assess their capacity to detect pathogenic Pythium species. These were orange tree leaves, tomato leaves, pepper leaves, geranium leaves, Bermuda grass leaves, pine needles, immature carnation petals, hemp-seed cotyledons, pepper and cucumber fruits. The Pythium spp. tested were P. aphanidermatum, P. irregulare and Pythium group F from hydroponic market garden crops in the Poniente region of Almería (south-east Spain). The test consisted of observing the velocity at which five baits were colonized and the day of colonization of the first bait. Results indicated that the slowest baits to be infected were immature carnation petals and pine needles. These two, together with Bermuda grass leaves, were also the baits infected in lowest number, such that practically no further infection was produced in the baits after the fifth day of contact with the inoculated water. The other plant baits tested were equally suitable for detection of Pythium spp. over the first two days, although only orange leaves and hemp-seed cotyledons were infected on the first day. 相似文献