Comparison of 5 Surgical Techniques for Partial Liver Lobectomy in the Dog for Intraoperative Blood Loss and Surgical Time

Objective: To compare surgical time and intraoperative blood loss for 5 partial liver lobectomy techniques in the dog. Study Design: Experimental in vivo study. Animals: Dogs (n=10). Methods: Five surgical techniques (SurgiTie^?; LigaSure^?; Ultracision^® Harmonic Scalpel [UAS]; Suction+Clip; Suction+thoracoabdominal stapler [TA]) for partial liver lobectomy in dogs were evaluated and compared for total surgical time and intraoperative blood loss. Body weight, activated clotting time (ACT), heart rate, and intraoperative blood pressure (BP) were recorded. Blood loss was determined by adding the weight of the blood soaked sponges during surgery (1 g=1 mL) to the amount of suctioned blood (mL). Surgical time (in seconds) was determined from the start of the lobectomy until cessation of bleeding from the stump. Mean surgical time and mean blood loss for each technique were compared using a Tukey's multiple comparison test. Results: No significant differences were found between dogs for weight, ACT, heart rate, and intraoperative BP. No complications were seen with the SurgiTie^? technique in 9 of 10 cases. There was no significant difference in surgical time between techniques however there was a significant difference for blood loss; the Suction+Clip method had significantly more blood loss than the other techniques. Conclusions: Skeletonization of the lobar vessels before individually clipping them (Suction+Clip) resulted in a higher blood loss than using Suction+TA, UAS, SurgiTie^? or the LigaSure^? device. The SurgiTie^? appears to be an acceptable method for partial liver lobectomy. Clinical Relevance: Although skeletonization and individually clipping the vessels had the highest blood loss, it still was <7.5% of total blood volume. All 5 techniques should be safe for clinical use in small to medium sized dogs up to 26 kg.     

Effect of Ergovaline Ingestion on Recovery of Horses Subjected to an Anaerobic Standard Exercise Test

The objective of this study was to determine whether consumption of tall fescue seed which contained high levels of ergovaline would affect post-exercise recovery of horses subjected to an anaerobic exercise test. Ten Quarter horses were separated into two groups and fed alfalfa hay, commercial sweet feed, and either endophyte-infected (E+) or endophyte-free (E−) ground tall fescue seed. Diets contained 11.8% seed, which resulted in 459 ppb of ergovaline for the E+ diet. During the first 28 days, horses in group A received E+ and group B received E−. Diets were reversed during the next 28 days (crossover design). Horses were ridden for 5 days per week. On day 14, 28 (period 1), 42, and 56 (period 2), they were subjected to a standardized exercise test (SET) that consisted of 41 turns in 4 minutes and was designed to raise the horse’s heart rate (HR) beyond the anaerobic threshold (150 bpm). There was a horse effect (P < .05) on post-SET respiration rate, HR, and post-exercise whole blood lactate level, but not rectal temperature (RT). For these variables or period effects, there was no horse × treatment, period × treatment, or period × horse interactions (P < .05). Treatment had no effect on whole blood lactate level, RT, or HR at any time measured. Respiration rate did not vary by treatment at rest or 1 minute after SET but was higher for the E+ treatment at 5 and 10 minutes after SET (P < .005). Consumption of diets that averaged 450 ppb of ergovaline caused the horses expend more respiratory effort in an attempt to recover to resting RT.     

为猪的矿物质需要设立NRC营养标准

为了理解NRC在公布猪营养标准时其数值为猪养分需要量的最佳估计值的这一事实,了解猪营养需要的评估过程是非常重要的。很明显,当猪的遗传品质得到改善以及更多的研究成果(阐明不同条件下猪的养分需要量)被用于生产时,猪的营养需要将会作出调整。     

Kinetic scaffolding mediated by a phospholipase C-beta and Gq signaling complex

Transmembrane signals initiated by a broad range of extracellular stimuli converge on nodes that regulate phospholipase C (PLC)-dependent inositol lipid hydrolysis for signal propagation. We describe how heterotrimeric guanine nucleotide-binding proteins (G proteins) activate PLC-βs and in turn are deactivated by these downstream effectors. The 2.7-angstrom structure of PLC-β3 bound to activated Gα(q) reveals a conserved module found within PLC-βs and other effectors optimized for rapid engagement of activated G proteins. The active site of PLC-β3 in the complex is occluded by an intramolecular plug that is likely removed upon G protein-dependent anchoring and orientation of the lipase at membrane surfaces. A second domain of PLC-β3 subsequently accelerates guanosine triphosphate hydrolysis by Gα(q), causing the complex to dissociate and terminate signal propagation. Mutations within this domain dramatically delay signal termination in vitro and in vivo. Consequently, this work suggests a dynamic catch-and-release mechanism used to sharpen spatiotemporal signals mediated by diverse sensory inputs.     

Wetland habitats of the Sabana de Bogotá Andean Highland Plateau and their birds

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生物拮抗菌Trichoderma harzianum处理玉米种子诱导实生苗的抗病性分析

 本文研究了生物拮抗菌Trichoderma harzianum(T22)处理对玉米(Mo17)实生苗生长的影响,以及对病原菌Colletrichonum graminicola的抗病性。试验结果表明:用拮抗菌T.harzianum处理后能明显地提高玉米苗根系发育和叶片生长,显著的诱导玉米叶片和根系中防御相关的酶活性和蛋白含量。用病原菌C.graminicola接种玉米叶片后观测发现,处理的实生苗叶片上病斑直径明显小于不处理的对照。尽管拮抗菌T.harzianum诱导植物抗病性的作用已被证实,但该研究更进一步揭示了T.harzianum处理玉米种子后植株的抗性应答与促进实生苗根系发育和叶片生长,以及诱导抗性相关的酶。     

Eight hundred years of clonal forestry in China: II. mass production of rooted cuttings of Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.)

Since 1986 a novel type of shoot orchard has been under development. Lower portions of the donor stems are buried horizontally in the soil and cuttings are taken from shoots that arise from them. This process apparently rejuvenates, so that mature trees of various ages can be propagated vegetatively. Seedlings of superior provenances, open-pollinated, and control-pollinated families, stump sprouts and upper branches of plus trees were used to establish the orchard, which contains about 40,000 donors and occupies 1.3 ha. Cuttings produced in this orchard can be rooted to about 85% success without hormones or shading. This shoot orchard provides more planting stock, and provides it five to six years earlier, than a seed orchard. The height and root-collar diameter of the rooted cuttings are greater than those of seedlings at outplant, and production costs are 15–20% lower than those associated with seedling production. Test plantations demonstrated that four-year height and diameter of cuttings and genetically similar seedlings are equivalent. This paper reports the details of this orchard, and summarizes other work on propagation and storage of Chinese fir cuttings.     

Modelling tillage translocation using step, linear-plateau and exponential functions

The distance over which soil is displaced and mixed during tillage has important implications for the understanding the dynamics of soil variability within complex soil-landscapes. In two preceding studies of tillage translocation, tillage was observed to displace soil over a length of approximately 1 m following single passes of four tillage implements (chisel plough, mouldboard plough, tandem disc and field cultivator), and over a length of approximately 2 m per sequence of conventional tillage (one pass of mouldboard plough, two passes of tandem disc and one pass of field cultivator). Using data from these studies step, linear-plateau and exponential functions were assessed for their ability to estimate the magnitude of translocation and the redistribution pattern of soil within the till-layer, and to predict the redistribution pattern of soil within the till-layer. On average, step, linear-plateau and exponential models estimated 100.0%, 100.2% and 102.5% of the magnitude of translocation and 76%, 88% and 93% of the soil redistribution pattern, respectively. Based on these results, it was concluded that linear-plateau and exponential functions are suitable models of tillage translocation. The exponential model was superior to the step and linear-plateau models, and an improvement over the existing diffusion model.     

Fecundity trends of Chinook salmon in the Pacific Northwest

Fecundity is an important demographic parameter that contributes to the productivity of anadromous fish stock dynamics. Yet, studies on fecundity patterns in Pacific salmon (Oncorhynchus spp.) often only include a few years of data, limiting our ability to understand spatio-temporal trends. Here, we used data on 43 hatchery Chinook salmon (O. tshawytscha, Salmonidae) populations in Washington State to evaluate whether average fecundity changed over the past three decades. We then used data from a subset of stocks (18) to evaluate the relationship between fecundity and body length. Our results revealed significant changes in fecundity across the 25-year study period with most stocks showing declines in fecundity over the past decade. Results further showed that Chinook salmon have decreased in length over this same period and that annual variation in mean length explains a majority (62%) of annual variation in mean fecundity. Specifically, we estimated that a 1-mm reduction in length results in 7.8 fewer eggs (95% CI = 6.6–8.9). Given that the majority of Pacific Northwest Chinook salmon in the environment and harvested in fisheries originate from hatchery releases and that nearby hatchery and wild populations generally have similar ocean distributions, these results likely reflect patterns for many populations not included. Combined, our results highlight the need to consider changes in body size and egg production when assessing the dynamics of anadromous fish populations and designing management or conservation plans, particularly for depressed populations.     

The large-effect drought-resistance QTL qtl12.1 increases water uptake in upland rice

Drought stress is the most important abiotic factor limiting upland rice yields. Identification of quantitative trait loci (QTL) conferring improved drought resistance may facilitate breeding progress. We previously mapped a QTL with a large effect on grain yield under severe drought stress (qtl12.1) in the Vandana/Way Rarem population. In the current paper, we present results from a series of experiments investigating the physiological mechanism(s) by which qtl12.1 affects grain yield under drought conditions. We performed detailed plant water status measurements on a subset of lines having similar crop growth duration but contrasting genotypes at qtl12.1 under field (24 genotypes) and greenhouse (14 genotypes) conditions. The Way Rarem-derived allele of qtl12.1 was confirmed to improve grain yield under drought mainly through a slight improvement (7%) in plant water uptake under water-limited conditions. Such an apparently small increase in water uptake associated with this allele could explain the large effect on yield observed under field conditions. Our results suggest that this improvement of plant water uptake is likely associated with improved root architecture.