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11.
Dannylo O. Sousa Hanne H. Hansen Ola Hallin Luiz G. Nussio Elisabet Nadeau 《Grass and Forage Science》2020,75(1):76-85
Red clover (Trifolium pratense) and lucerne (Medicago sativa) are among the most common legume species used for ruminant feeding systems. Besides the greater nutritive quality and first-year ley yield compared to lucerne, red clover decreases its yield over the years. However, under unfavourable soil conditions the persistency of lucerne can be compromised, not performing as expected. This study compared yield and chemical composition of eight lucerne cultivars and one tetraploid red clover cultivar, with similar growth capacity as lucerne, replicated over two years. In the second year, four lucerne cultivars and the red clover cultivar were analysed for crude protein (CP) fractions, dry matter and neutral detergent fibre (NDF) digestibility. A randomized block design was used with three field blocks per cultivar for the multiple comparisons within each year. There were differences in DM yield, concentrations of CP and NDF and CP fractions among the lucerne cultivars, but the differences were inconsistent between years and between growth cycles within year. The red clover cultivar had lower CP and NDF concentrations than a majority of the lucerne cultivars, and greater in vitro organic matter digestibility compared to all of the lucerne cultivars. Also, the red clover cultivar had greater rumen undegradable-to-degradable CP ratio but confirmed its lower yield persistency compared to the lucerne cultivars. 相似文献
12.
Hamed Elsayed Rasha Attia Ola Mohamed Ahmed Haroun Nabil El-Sayed 《Fibers and Polymers》2018,19(4):832-842
Leather finishing processes using toxic organic solvent based produce volatile organic compounds (VOC), chronic exposure to this chemicals effect on workers' health causing many diseases especially lung cancer. So, polyurethane waterbased was synthesized for application in leather finishing instead of organic solvent based because it’s economic and safety for industry and workers. Preparation of water-based polyurethane (PU) depends on the reaction of polyethylene glycol (PEG, 300) with isophorone diisocyanate (IPDI) and the reaction of IPDI-1,4-butanediol (BDO) together with dimethylolpropionic acid (DMPA), was synthesized by poly-addition polymerization reaction. PU was then modified with different amounts of silicon dioxide nanoparticles (1-5 % SiO2), used as a binder in leather finishing. Leather coated was characterized physically, chemically and thermally by FTIR, GPC, DLS, TEM, SEM and TGA. The results revel that, water vapor permeability (WVP) of leather coated with PU modified with SiO2 showed improvement due to the existence of SiO2 particles which increases the interspaces of the polyurethane coating. SEM showed that when the amount of SiO2 nanoparticles increases, there is uniform nanoparticles accumulated can be observed. EDX prove the presence of Si and O2 elements and the formation of SiO2 nanoparticles. Mechanical properties discussed that tensile strength; tear strength and elongation at break % increase with increase SiO2 concentration until 3 % SiO2 nanoparticles. TGA showed an improvement of thermal stability of coated leather modified with SiO2. Therefore, this study succeeded in preparation of safe, ecofriendly of water-based polyurethane binders which modified with SiO2 for using in leather finishing. 相似文献
13.
Structure and receptor specificity of the hemagglutinin from an H5N1 influenza virus 总被引:3,自引:0,他引:3
Stevens J Blixt O Tumpey TM Taubenberger JK Paulson JC Wilson IA 《Science (New York, N.Y.)》2006,312(5772):404-410
The hemagglutinin (HA) structure at 2.9 angstrom resolution, from a highly pathogenic Vietnamese H5N1 influenza virus, is more related to the 1918 and other human H1 HAs than to a 1997 duck H5 HA. Glycan microarray analysis of this Viet04 HA reveals an avian alpha2-3 sialic acid receptor binding preference. Introduction of mutations that can convert H1 serotype HAs to human alpha2-6 receptor specificity only enhanced or reduced affinity for avian-type receptors. However, mutations that can convert avian H2 and H3 HAs to human receptor specificity, when inserted onto the Viet04 H5 HA framework, permitted binding to a natural human alpha2-6 glycan, which suggests a path for this H5N1 virus to gain a foothold in the human population. 相似文献
14.
Thorleifsson G Magnusson KP Sulem P Walters GB Gudbjartsson DF Stefansson H Jonsson T Jonasdottir A Jonasdottir A Stefansdottir G Masson G Hardarson GA Petursson H Arnarsson A Motallebipour M Wallerman O Wadelius C Gulcher JR Thorsteinsdottir U Kong A Jonasson F Stefansson K 《Science (New York, N.Y.)》2007,317(5843):1397-1400
Glaucoma is a leading cause of irreversible blindness. A genome-wide search yielded multiple single-nucleotide polymorphisms (SNPs) in the 15q24.1 region associated with glaucoma. Further investigation revealed that the association is confined to exfoliation glaucoma (XFG). Two nonsynonymous SNPs in exon 1 of the gene LOXL1 explain the association, and the data suggest that they confer risk of XFG mainly through exfoliation syndrome (XFS). About 25% of the general population is homozygous for the highest-risk haplotype, and their risk of suffering from XFG is more than 100 times that of individuals carrying only low-risk haplotypes. The population-attributable risk is more than 99%. The product of LOXL1 catalyzes the formation of elastin fibers found to be a major component of the lesions in XFG. 相似文献
15.
Ola Vahl 《Aquaculture (Amsterdam, Netherlands)》1979,17(3):221-229
An hypothesis on the control of voluntary food intake (appetite) in fish is presented. According to the hypothesis, only two parameters are necessary to design a feeding regime which might result in maximum growth of fish in an aquaculture system. The necessary parameters are maximum voluntary food intake in one meal, and evacuation rate of the stomach. This hypothesis is discussed in relation to empirical data. 相似文献
16.
Anders Foldvik Sigurd Einum Anders G. Finstad Ola Ugedal 《Ecology of Freshwater Fish》2017,26(2):260-270
The spatial scale of environmental factors influencing population dynamics ranges from microhabitat to continental or even global scales. Integration of multiple spatial scales is important in order to understand links between environmental variation and population processes. In the present study, we investigate how multiscale drivers influence the production of stream‐rearing Atlantic salmonids (Atlantic salmon, Salmo salar L. and brown trout, Salmo trutta L.) measured in terms of abundance. Variation in juvenile production was studied using data from single‐pass electrofishing surveys (measured as biomass per m2) from nine rivers. These data were combined with habitat data ranging from an important in‐stream microhabitat variable (shelter availability) to properties of the catchment. Variation in productivity within and among rivers was affected by both properties of in‐stream habitat and catchment properties. Shelter availability and the proportion of the catchment consisting of cultivated land and lakes influenced biomass positively, while catchment area had the opposite effect. For a different set of rivers (N = 20), river gradient and catchment area were shown to positively affect the amount of shelter. Finally, the variables identified in the two preceding analysis were included in the analysis of population productivity using catch statistics from 160 rivers. The proportion of cultivated land and lakes, estimated shelter availability were found to have positive effects. In addition, temperature had a positive effect, while river width had a negative effect. This study shows that combining multiple‐scale environmental factors can explain a substantial proportion of variation in population productivity among and within the populations of Atlantic salmonids. 相似文献
17.
Roald Stre 《海洋水产研究》2001,22(4):21-28
IntroductionThe China Sea is divided into four sea regions(Fig.1) :the Bohai Sea(BS) ,the Yellow Sea(YS) ,theEast China Sea(ECS) and South China Sea(SCS) .The Bohai Sea,the Yellow Sea and the shelf of the EastChina Sea together form a broad epicontinental Sea.The average depth of Bohai Sea is18m and that of Yellow Sea is4 4m.Together,the Bohai Sea and Yel-low Sea form a gulf opening to the ECS.A shallow trough runs through the gulf and can be traced south tothe northern end o… 相似文献
18.
Liska WD Marcellin-Little DJ Eskelinen EV Sidebotham CG Harrysson OL Hielm-Björkman AK 《Veterinary surgery : VS》2007,36(4):293-301
Objective— To report surgical planning, technique, and outcome of custom total knee replacement (TKR) performed to manage a medial femoral condylar nonunion in a dog.
Study Design— Clinical case report.
Animal— A 3-year-old, 20 kg Karelian Bear Hound.
Methods— Computed tomographic scan of the left pelvic limb was used to build a stereolithography model of the distal portion of the femur. The model was used to create a custom augment to replace the missing medial femoral condyle and a custom stem for intramedullary condylar cemented fixation. The augment and stem were adapted to femoral and tibial components already available. The model was used to rehearse the surgery and then the custom prosthesis was implanted.
Results— Weight bearing returned 8 hours after surgery and improved thereafter. Joint alignment was normal and prosthetic joint motion was 60–165° postoperatively. The dog resumed moose hunting 3 months after surgery. Peak vertical force and impulse of the operated limb measured 17 months after surgery were 65% and 47% of the normal, contralateral limb.
Conclusion— Based on short-term follow-up, cemented canine TKR was successfully achieved for management of a severely abnormal stifle joint.
Clinical Relevance— With further refinement and development of commercially available prostheses, TKR should be possible for canine patients. 相似文献
Study Design— Clinical case report.
Animal— A 3-year-old, 20 kg Karelian Bear Hound.
Methods— Computed tomographic scan of the left pelvic limb was used to build a stereolithography model of the distal portion of the femur. The model was used to create a custom augment to replace the missing medial femoral condyle and a custom stem for intramedullary condylar cemented fixation. The augment and stem were adapted to femoral and tibial components already available. The model was used to rehearse the surgery and then the custom prosthesis was implanted.
Results— Weight bearing returned 8 hours after surgery and improved thereafter. Joint alignment was normal and prosthetic joint motion was 60–165° postoperatively. The dog resumed moose hunting 3 months after surgery. Peak vertical force and impulse of the operated limb measured 17 months after surgery were 65% and 47% of the normal, contralateral limb.
Conclusion— Based on short-term follow-up, cemented canine TKR was successfully achieved for management of a severely abnormal stifle joint.
Clinical Relevance— With further refinement and development of commercially available prostheses, TKR should be possible for canine patients. 相似文献
19.
Ola Syrstad 《Livestock Production Science》1977,4(2):141-151
The day-to-day variation in fat and protein content of milk from individual cows was studied in two series of data. In the second series, variation in milk yield was also investigated. The data were records of single milkings over a period of two weeks.For daily records obtained by combining a.m. and p.m. milkings, the standard deviations found in the first series were 0.39 and 0.10 percentage units for fat and protein content, respectively. In the second series, standard deviations of 1.57 kg for milk, 0.36 units for fat and 0.08 units for protein were computed. Standard deviations between records of consecutive days (second series only) were 1.24 kg for milk, 0.35 units for fat and 0.06 units for protein.Within-cow coefficients of correlation between consecutive a.m. and p.m. milkings were positive but small except for protein. Within-cow coefficients of correlation between pairs of traits at the same milking were consistently small, but highly significant.The interpretation of the results is discussed. 相似文献
20.
Formation of harvest units with genetic algorithms 总被引:6,自引:0,他引:6
Operational planning is normally based on stands as the primary unit of treatment. In recent years, interest has been directed towards the use of smaller area units such that the formation of treatment units becomes part of the operational planning. Here, the method of genetic algorithms was used in order to delineate harvesting units in a forest described as a grid of 20 m × 20 m pixels. Remote sensing data and inventory plots were employed to derive pixel estimates of forest variables. Appropriate parameter settings for the algorithm were investigated for two cases that consisted of 26 × 25 pixels. Based on the experience from these tests, the algorithm was employed in forming treatment units in an area encompassing 100 × 100 grid cells, or 400 ha. Due to the size of the problem, a two-stage procedure was suggested. The solutions of the genetic algorithm were compared with a heuristic, a cell removal algorithm, that was proposed in earlier studies of treatment unit formation. The genetic algorithm performed better than the heuristic for all the cases that were tested. 相似文献