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231.
The effects of stand stem density (SSD), orientation and distance with respect to shelter trees, and fertilisation on planted
Pinus sylvestris and Picea abies seedlings were examined at two sites, one with a southerly aspect (64°14′N, 19°46′E, 225 m
a.s.l.) and one with a northerly aspect (64°09′N, 19°36′E, 274 m a.s.l.) in boreal forests in Sweden. The damage and growth
were compared at these sites in stands with three SSD’s and different light regimes: uncut forest (SSD 500, ~500 stems/ha),
shelterwood (SSD 150,~150 stems/ha), and clear-cut (SSD, 0 stems). Half of the seedlings were irrigated with fertiliser (10 mM N).
Fertilisation and SSD affected the height growth of P. abies, since fertilised seedlings in SSD 0 grew the most (22.2 cm).
Fertilised seedlings in SSD 0 also generally had the greatest biomass (twigs, leading shoot and needles), even P. sylvestris
seedlings on the North slope, where fertilised and unfertilised pine seedlings in SSD 0 had 62.6 and 39.7 g biomass, respectively.
P. sylvestris increased about 150% in dry mass of leading shoot of the increase of P. abies with equal height growth, when
comparing SSD 150 and SSD 0. The results indicate that the general conditions of the stand have stronger effects on the growth
of planted seedlings than their orientation and distance with respect to the nearest tree and that light requirements cannot
be moderated by fertilisation. We postulate that a system in which forest gaps are formed under a shelterwood could provide
a way to regenerate forests that exploits the beneficial features of both shelter trees and clear-cuts. 相似文献
232.
Sergey Hegay Mulatu Geleta Tomas Bryngelsson Abdybek Asanaliev Larisa Garkava-Gustavsson Helena Persson Hovmalm Rodomiro Ortiz 《Genetic Resources and Crop Evolution》2014,61(3):555-566
Common bean (Phaseolus vulgaris) is an important export crop in Kyrgyzstan since the end of the twentieth century. Genetic diversity analysis of common bean populations is useful for breeding programs, as it helps to select genetic material to be used for further crossing. Twenty-seven common bean accessions were analyzed using 13 qualitative morphological traits. In some cases, obtained morphological data were combined with previously published results based on microsatellite markers. The similarity matrices generated from the molecular and morphological data were significantly correlated (r = 0.49, P < 0.01). Cluster analyses based on Dice’s similarity coefficient were constructed based on morphological data and the combined data set of morphology and microsatellite, and both grouped the 27 accessions according to their origin: 15 belonged to the Andean and 12 to the Mesoamerican gene pool. On average, the Andean accessions were less diverse than the Mesoamerican accessions. The average diversity based on the Shannon diversity index for the 13 qualitative morphological traits was 0.05. Overall, this study revealed that qualitative morphological markers are efficient in assigning modern cultivars to their gene pools of origin. 相似文献
233.
Davídek T Devaud S Robert F Blank I 《Journal of agricultural and food chemistry》2006,54(18):6667-6676
The formation of acetic acid was elucidated based on volatile reaction products and related nonvolatile key intermediates. The origin and yield of acetic acid were determined under well-controlled conditions (90-120 degrees C, pH 6-8). Experiments with various 13C-labeled glucose isotopomers in the presence of glycine revealed all six carbon atoms being incorporated into acetic acid: C-1/C-2 ( approximately 70%), C-3/C-4 ( approximately 10%), and C-5/C-6 (approximately 20%). Acetic acid is a good marker of the 2,3-enolization pathway since it is almost exclusively formed from 1-deoxy-2,3-diulose intermediates. Depending on the pH, the acetic acid conversion yield reached 85 mol % when using 1-deoxy-2,3-hexodiulose (1) as a precursor. Hydrolytic beta-dicarbonyl cleavage of 1-deoxy-2,4-hexodiuloses was shown to be the major pathway leading to acetic acid from glucose without the intermediacy of any oxidizing agents. The presence of key intermediates was corroborated for the first time, i.e., tetroses and 2-hydroxy-3-oxobutanal, a tautomer of 1-hydroxy-2,3-butanedione, also referred to as 1-deoxy-2,3-tetrodiulose. The hydrolytic beta-dicarbonyl cleavage represents a general pathway to organic acids, which corresponds to an acyloin cleavage or a retro-Claisen type reaction. Although alternative mechanisms must exist, the frequently reported hydrolytic alpha-dicarbonyl cleavage of 1 can be ruled out as a pathway forming carboxylic acids. 相似文献
234.
BackgroundLaryngeal paralysis is a common idiopathic degenerative neurological disease in older medium-to-large breed dogs, with surgical correction of the obstruction being the treatment of choice.ObjectivesThis study evaluated the use of laryngeal silicone stents to treat canine laryngeal paralysis in dogs where classic surgical treatment was not accepted by the owners.MethodsDogs diagnosed with laryngeal paralysis, for which the owners refused arytenoid lateralization surgery as a first-line treatment, were treated with laryngeal silicone stents.ResultsSix dogs with bilateral laryngeal paralysis were included in the study. All dogs showed improvement in clinical signs immediately after the procedure. No clinical signs or radiographic changes were noted in four out of six dogs in the follow-up visit performed 1 wk later. One dog was suspected of aspirating water while drinking, but the signs disappeared after repositioning the stent. Another dog had a relapse of stridor due to caudal migration of the stent. This dog underwent arytenoid lateralization surgery because larger stents are not commercially available. At the time of writing, between seven and 13 mon after stent placement, no significant incidents have occurred in four dogs, and all owners report a satisfactory quality of life.ConclusionsLaryngeal silicone stenting is an interesting alternative for treating dogs with acquired laryngeal paralysis when the owners refuse classic arytenoid lateralization surgery. Furthermore, stent placement can be a temporary solution to stabilize these dogs until a permanent surgical treatment can be performed. 相似文献
235.
Ivana Hyrslova Gabriela Krausova Iva Mrvikova Barbora Stankova Tomas Branyik Hana Malinska Martina Huttl Antonin Kana Ivo Doskocil 《Marine drugs》2022,20(12)
The unicellular green microalga Dunaliella is a potential source of a wide range of nutritionally important compounds applicable to the food industry. The aim of this study was to assess the effect of Dunaliella salina dried biomass on the growth and adherence of 10 strains of Lactobacillus, Lacticaseibacillus, and Bifidobacterium. The immunomodulatory, antioxidant, and cytotoxic effects of D. salina on human peripheral mononuclear cells and simulated intestinal epithelial cell lines Caco-2 and HT-29 were evaluated. Furthermore, the hypocholesterolemic effects of the microalgae on lipid metabolism in rats fed a high-fat diet were analyzed. The addition of D. salina biomass had a positive effect on the growth of nine out of 10 probiotics and promoted the adherence of three bifidobacteria strains to human cell lines. The antioxidant and immunomodulatory properties of D. salina were concentration-dependent. The inflammatory cytokines (TNF-α and IL-6) were significantly increased following Dunaliella stimulation at the lowest concentration (0.5% w/v). Eight week supplementation of D. salina to the diet of hypercholesteromic rats significantly decreased the serum concentrations of LDL-C, VLDL, IDL-B, and IDL-C. D. salina is not cytotoxic in intestinal cell models; it promotes adherence of selected bifidobacteria, it affords immunomodulatory and antioxidant effects, and its addition to diets may help decrease atherosclerosis risk factors. 相似文献
236.
基于ALR-GMM的群养猪攻击行为识别算法研究 总被引:2,自引:0,他引:2
群养猪攻击行为是评估猪群对微环境适应性的重要指标.活动指数模型能够描述猪群行为模式,已经在群养猪攻击行为识别研究中得到初步验证.然而,养殖设施的差异性和动态背景环境等因素所导致的环境适应性差是限制其商业化应用的主要障碍.本文基于递归背景建模思想,在高斯混合模型(GMM)中引人双曲正切函数,提出了一种自适应学习率GMM的... 相似文献