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221.
Objective To determine the effect of ocular blinkers on driving horses’ reactions to visual and audible stimuli. Design Balanced crossover trial with horses randomly assigned to either wear blinkers or not wear blinkers first or second, then subjected to repeated sequences of four distinct stimuli (chain rattle, cap gun, umbrella opening, and shaking of an aluminum can containing coins). Two weeks later, this process was repeated with the ordering of wearing blinkers reversed. Animal studied Eight driving horses of various breeds. Procedures Responses were recorded quantitatively as inter‐beat times (the time between each heart beat in msec) and qualitatively via video recording. Statistical analysis of the first 10 s of inter‐beat times poststimulus assessed the effect of the presence of blinkers, order of blinker application and stimulus type using a linear regression model with a random effect for horse. Results Wearing blinkers is significantly associated with a decrease in the inter‐beat times (increase in heart rate) when they are worn by horses experiencing an unfamiliar sound. However, wearing blinkers is significantly associated with an increase in the inter‐beat times (decrease in heart rate) when worn by horses experiencing a primarily visual, familiar stimulus. Conclusions and Clinical Relevance Trained driving horses, when they wear blinkers, have a decrease in inter‐beat time (an increase in heart rate) when there is an unfamiliar sound. This may have relevance to horses who have limited vision caused by trauma or disease. 相似文献
222.
Joan Casals Laura Pascual Joaquín Cañizares Jaime Cebolla-Cornejo Francesc Casañas Fernando Nuez 《Scientia Horticulturae》2011
Following consumer complaints about the quality of modern varieties of tomato, landraces have strengthened their quality markets. In Spain, two tomato landraces, ‘Montserrat’ and ‘Pera Girona’, are grown in contiguous areas and have different market niches. We used amplified fragment length polymorphism (AFLP) to characterize 13 accessions of Montserrat, 14 accessions of Pera Girona, and 4 control varieties. We found a narrow genetic base for ‘Montserrat’ and ‘Pera Girona’ (8.5% of polymorphic loci) and no differences between the landraces. We studied agronomical and sensory traits to determine why the two landraces continue to have separate market niches. We found high variability among accessions within each landrace and overlapping among accessions of both landraces for all traits except fruit morphology. Consumers probably came to associate the organoleptic quality of these landraces with their external traits, but due to spontaneous crossings and introgressions these relations have been lost. Selection within landraces will be necessary to reestablish the link between morphology and sensory value and to consolidate these quality markets. 相似文献
223.
Webber JM 《Science (New York, N.Y.)》1934,80(2073):268-269
224.
Variations in the distribution pattern of soil water repellency (SWR) and soil moisture are of major importance for the hydrological and geomorphological processes in Mediterranean burned areas, and also for their ecological implications concerning to re-establishment of the vegetation cover. This paper studies the influence of Rosmarinus officinalis L. and Quercus coccifera L. vegetated patches on SWR and their relationships with soil moisture content (SMC) and soil organic matter (SOM) in burned and unburned calcareous soils of a Mediterranean shrubland ecosystem, considering the first rainfall event occurred after the wildfire in Les Useres (Castellón, eastern Spain). 相似文献
225.
C??sar Valderrama Joan I. Barios Adriana Farran Jos?? Luis Cortina 《Water, air, and soil pollution》2011,215(1-4):285-297
This work was conducted to evaluate the sorption performance of hyper-cross-linked Macronet resin (MN200) compared to the granular activated carbon in order to remove phenol and aniline from aqueous solution in both single and binary solutions. Fixed-bed column experiments were used to obtain the breakthrough curves. The experimental data were fitted to the Thomas, Bed Depth Service Time and Yoon?CNelson models, well-established fixed-bed sorption models. The theoretical sorption capacities obtained by the Thomas model were in good agreement to the breakthrough capacities determined from the sorption data. The sorption capacity decreased in binary sorption for resin MN200, while activated carbon reported similar (aniline) or higher (phenol) sorption performance indicating a synergistic effect between both solutes on the activated carbon surface. A good prediction of the breakthrough curves in binary solution was obtained by using an approach that considers a simple model to describe a breakthrough curve (Thomas) and modified isotherm equilibrium. The resin MN200 fixed-bed columns were easily regenerated by using a methanol solution, reporting more above of 90% of recovery for both solutes, while about 50% was the recovery of activated carbon after single experiments. The regeneration after the binary sorption experiments reported a decrease in the solute recovery, effect that was especially evident for activated carbon. 相似文献
226.
227.
Bernhard JM 《Science (New York, N.Y.)》2003,299(5608):861
228.
229.
Pelling AE Sehati S Gralla EB Valentine JS Gimzewski JK 《Science (New York, N.Y.)》2004,305(5687):1147-1150
We demonstrate that the cell wall of living Saccharomyces cerevisiae (baker's yeast) exhibits local temperature-dependent nanomechanical motion at characteristic frequencies. The periodic motions in the range of 0.8 to 1.6 kHz with amplitudes of approximately 3 nm were measured using the cantilever of an atomic force microscope (AFM). Exposure of the cells to a metabolic inhibitor causes the periodic motion to cease. From the strong frequency dependence on temperature, we derive an activation energy of 58 kJ/mol, which is consistent with the cell's metabolism involving molecular motors such as kinesin, dynein, and myosin. The magnitude of the forces observed ( approximately 10 nN) suggests concerted nanomechanical activity is operative in the cell. 相似文献
230.
Selection can favor reproductive altruism if an altruism allele aids copies of itself by helping relatives. The alternative "greenbeard" mechanism, in which an allele directly recognizes and aids copies of itself in others, is generally thought to be too complex for a single gene to carry out. The csA gene in Dictyostelium discoideum acts as a single-gene greenbeard. When wild-type cells are mixed with csA-knockout cells, the wild type is more altruistic, but is also able preferentially to direct the benefits to other wild-type cells. Both properties derive directly from homophilic cell adhesion of the protein encoded by csA. 相似文献