Effect of group size and structure on the welfare and performance of pregnant sows in pens with electronic sow feeders          下载免费PDF全文

Leena Anil  Sukumarannair S. Anil  John Deen  Samuel K. Baidoo    Roger D. Walker 《Canadian journal of veterinary research》2006,70(2):128-136

Pregnant sows were housed in dynamic, twice-mixed, and static groups of different sizes in pens with electronic sow feeders (ESFs) to study the effect of group size and structure on sow welfare and performance. The total injury score (TIS) was significantly higher (P < 0.05) in the dynamic group than in the other groups in general and 2 wk after mixing. The salivary cortisol concentrations were similar in the 3 groups. The frequency of queuing was significantly higher (P < 0.05) in the twice-mixed group and the frequency of nonagonistic social interactions significantly lower (P < 0.05) in the dynamic group. The total number of aggressive acts was positively and significantly correlated (P < 0.05) with the frequency and duration of queuing in all the groups. Farrowing performance and longevity did not differ between the groups. The higher TIS and lower number of nonagonistic social interactions indicated that welfare was compromised in the dynamic group as compared with the other groups.  相似文献   

Sexual Reproduction of European Aspen (Populus tremula L.) at Prescribed Burned Site: The Effects of Moisture Conditions     

Tarja Latva-Karjanmaa  Leena Suvanto  Kari Leinonen  Hannu Rita 《New Forests》2006,31(3):545-558

Aspen (Populus tremula) is capable of reproducing both sexually and asexually from root suckers, the latter being more common. Seedlings are rare even though potential seed production is enormous. The aim of this study was to find out how different moisture conditions affect emergence and survival of aspen seedlings on burned soil. We set up a sowing experiment on mineral soil and on humus. The sowing was done at 240 microsites (θ7 cm) in 15 blocks (1×1 m). Treatments were sowing time, watering and sowing shelter. A total of 1463 seedlings emerged on mineral soil and 26 on humus. Watering, covering, their interaction, block and sowing time had significant effects on the number of seedlings. The largest numbers of seedlings were recorded at microsites that were watered and covered. The survival of seedlings was 20% during the growing season and 45% over winter. We conclude that seedbed conditions and moisture are the most essential factors for sexual reproduction of aspen. Short-term weather conditions have an important effect on seedling emergence and are likely to greatly affect field studies.  相似文献   

The effect of red wood ant (<Emphasis Type="Italic">Formica rufa</Emphasis> group) mounds on root biomass,density, and nutrient concentrations in boreal managed forests   总被引：2，自引：1，他引：2  

Mizue Ohashi  Jouni Kilpeläinen  Leena Finér  Anita C. Risch  Timo Domisch  Seppo Neuvonen  Pekka Niemelä 《Journal of Forest Research》2007,12(2):113-119

Red wood ants (Formica rufa group, RWAs) are common insects in boreal forests in Fennoscandia, and they build large, long-lived mounds as their nests. RWA mounds are enriched with carbon and nutrients, but little information is available about how they affect root distribution and the nutrient uptake of trees. In this study, we investigated the biomass, biomass density, nutrient concentrations, and amounts of fine (<2 mm) and coarse (>2 mm) roots in RWA mounds, and compared them with those of surrounding forest soil in mixed coniferous stands of different age classes in Finland. Neither fine nor coarse root biomasses differed significantly between the aboveground parts of the mounds and the organic layer of the soil. Root biomass density was lower in mounds than in the organic layer. However, fine root biomass and biomass density were higher in the belowground parts of mounds than in the surrounding mineral soil. Macroelement (N, Ca, K, P, S, Mg) and Zn and Cu concentrations in roots in the mounds were significantly higher than those in the organic layer. Root biomass and biomass density did not differ between stands of different age classes. The results of this study indicate that RWA mounds increase heterogeneity in root distribution in forest ecosystems, and also increase the availability of nutrients for plants that extend their roots inside RWA mounds.  相似文献   

Irreversible diameter change of wood segments correlates with other methods for estimating frost tolerance of living cells in freeze-thaw experiment: a case study with seven urban tree species in Helsinki     

Anna Lintunen  Teemu Paljakka  Anu Riikonen  Leena Lindén  Lauri Lindfors  Eero Nikinmaa  Teemu Hölttä 《Annals of Forest Science》2015,72(8):1089-1098

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Delayed soil thawing affects root and shoot functioning and growth in Scots pine     

Repo T  Lehto T  Finér L 《Tree physiology》2008,28(10):1583-1591

In boreal regions, soil can remain frozen after the start of the growing season. We compared relationships between root characteristics and water relations in Scots pine (Pinus sylvestris L.) saplings subjected to soil frost treatments before and during the first week of the growing period in a controlled environment experiment. Delayed soil thawing delayed the onset of sap flow or totally blocked it if soil thawing lagged the start of the growing period by 7 days. This effect was reflected in the electrical impedance of needles and trunks and in the relative electrolyte leakage of needles. Prolonged soil frost reduced or completely inhibited root growth. In unfrozen soil, limited trunk sap flow was observed despite unfavorable aboveground growing conditions (low temperature, low irradiance, short photoperiod). Following the earliest soil thaw, sap flow varied during the growing season, depending on light and temperature conditions, phenological stage of the plant and the amount of live needles in the canopy. The results suggest that delayed soil thawing can reduce tree growth, and if prolonged, it can be lethal.  相似文献   

Effect of chemical softening of coconut fibres on structure and properties of its blended yarn with jute     

Leena Mishra  Gautam Basu  Ashish Kumar Samanta 《Fibers and Polymers》2017,18(2):357-368

Coconut fibres were subjected to chemical treatment to obtain softer and finer fibres, suitable to blend with other finer fibre like jute. The chemical softening recipe was optimized using Box-Behnken design of experiments as 40 % Na₂S, 10 % NaOH and 6 % Na₂CO₃, which notably reduced the fineness (33 %) and flexural rigidity (74 %) and improved tensile property of coconut fibre. Effect of softening of coconut fibre on its process performance was studied in high speed mechanized spinning system at different blend ratios with jute. Blending with jute assists in spinning of coconut fibre to produce yarn of 520 tex at production rate of 5-6 kg/h, as compared to 15 kg/day for hand spun 5300 tex raw coconut fibre yarn in manual system. Analysis of blended yarn structure in terms of packing density, radial distribution of fiber components (SEM) and mass irregularity were investigated. SEM shows yarns made from softened coconut fibre -jute blends are more compact than raw coconut fibre -jute blend yarns. Coconut fibres were preferentially migrated to core of the yarn. Major yarn properties viz., tensile strength, and flexural rigidity of raw and chemically softened blended yarns were compared against their finest possible 100 % coconut fibre yarn properties. Yarn made up to 50:50 chemically softened coconut fibre-jute blend showed much better spinning performance, and having superior property in terms of reduced diameter, higher compactness, strength, initial modulus and less flexural rigidity than 100 % raw, 100 % chemically softened coconut fibre rope, and raw coconut fibre-jute blend yarns.  相似文献   

Ovipositional responses of the pulse beetle, Bruchus chinensis (Coleoptera: Bruchidae) to extracts and compounds of Capparis decidua     

Upadhyay RK  Rohatgi L  Chaubey MK  Jain SC 《Journal of agricultural and food chemistry》2006,54(26):9747-9751

Extracts of Capparis decidua stems and flowers showed insecticidal and oviposition inhibitory activities against Bruchus chinensis. The LC50 values of these extracts were found to increase with the increase in the polarity of the extract at different exposure periods. For instance, after 96 h, the LC50 values were found to be 3.619, 7.319, and 10.151 microg for CD1, CD2, and CD3, respectively. Extract CD7 was effective only at higher doses. The toxicity was found to be dose- and time-dependent. The females laid lesser number of eggs, when exposed to sublethal doses of different extracts and pure compounds, as compared to control. The maximum oviposition deterrence index was found for extract CD1 followed in decreasing order by CD2, CD3, and CD7. From extract CD1, two compounds were isolated and characterized as triacontanol (C1) and 2-carboxy-1,1-dimethylpyrrolidine (C2). When the females were exposed to sublethal doses of these compounds, they laid lesser number of eggs as compared to the control. C2 was found to have a slightly greater oviposition inhibition effect than C1. From fraction CD7, one novel compound labeled as CDF1 has been isolated and identified as 6-(1-hydroxy-non-3-enyl)tetrahydropyran-2-one. CDF1 has also shown insecticidal and oviposition inhibitory activities against B. chinensis at low concentrations.  相似文献   

Climate change mitigation through increased wood use in the European construction sector—towards an integrated modelling framework     

Ljusk Ola Eriksson  Leif Gustavsson  Riitta H?nninen  Maarit Kallio  Henna Lyhyk?inen  Kim Pingoud  Johanna Pohjola  Roger Sathre  Birger Solberg  Jarle Svanaes  Lauri Valsta 《European Journal of Forest Research》2012,131(1):131-144

Using wood as a building material affects the carbon balance through several mechanisms. This paper describes a modelling approach that integrates a wood product substitution model, a global partial equilibrium model, a regional forest model and a stand-level model. Three different scenarios were compared with a business-as-usual scenario over a 23-year period (2008?C2030). Two scenarios assumed an additional one million apartment flats per year will be built of wood instead of non-wood materials by 2030. These scenarios had little effect on markets and forest management and reduced annual carbon emissions by 0.2?C0.5% of the total 1990 European GHG emissions. However, the scenarios are associated with high specific CO₂ emission reductions per unit of wood used. The third scenario, an extreme assumption that all European countries will consume 1-m³ sawn wood per capita by 2030, had large effects on carbon emission, volumes and trade flows. The price changes of this scenario, however, also affected forest management in ways that greatly deviated from the partial equilibrium model projections. Our results suggest that increased wood construction will have a minor impact on forest management and forest carbon stocks. To analyse larger perturbations on the demand side, a market equilibrium model seems crucial. However, for that analytical system to work properly, the market and forest regional models must be better synchronized than here, in particular regarding assumptions on timber supply behaviour. Also, bioenergy as a commodity in market and forest models needs to be considered to study new market developments; those modules are currently missing.  相似文献   

沙棘油对过敏性皮炎患者皮肤表层粗糙程度的影响     

杨宝茹  Kirsti O.Kalimo  Leena M.Mattila  Heikki P.Kallio 《国际沙棘研究与开发》2004,2(1):44-47

为验证沙棘籽油和沙棘果油对过敏性皮炎患者皮肤表层粗糙程度的影响，进行了有安慰剂对照的平行性研究。16位患者在4个月内每日分别服用5g沙棘籽油，沙棘果油或石蜡油。本研究包括皮肤表面粗糙程度的测量方法和测量参数的优化选择以及服油前、后手背和肩部非病变区皮肤表面的粗糙程度的测量。实验结果表明，服油前后皮肤表面的粗糙程度无明显统计学变化，说明沙棘油对过敏性皮炎患者非病变区皮肤的影响小于对病变区皮肤的影响。由于本研究中患者人数有限，此结论有待进一步验证。用表面光度测量仪可明显指示不同部位皮肤表层结构和粗糙程度的差异，在对皮肤的研究方面有广泛的应用前景。  相似文献   

Enhanced separation and characterization of gluten polymers by asymmetrical flow field-flow fractionation coupled with multiple detectors     

Leena Pitkänen  Tuula Sontag-Strohm  Päivi Kanerva 《Journal of Cereal Science》2014

Asymmetrical flow field-flow fractionation (AsFlFFF) coupled with refractive index (RI) and multi-angle light scattering (MALS) detectors was used for macromolecular characterization of four different industrial wheat protein preparations (native, enzymatically hydrolyzed, physically separated, and denatured). The fractionation conditions were optimized separately for each protein sample and molar masses were determined from RI and MALS signals. Decaying cross-flow gradient seemed to produce best results for most of the gluten samples in terms of resolution and sample recovery. Sonication of the samples enabled the solubilization of the high-molar mass components with molar mass ranging from 8 × 10⁶ to 3.5 × 10⁸ g/mol. In case of lower-molar mass glutenins (α-gliadins, ω-gliadins, and high molecular weight glutenin subunits), AsFlFFF results were also compared with the results obtained with capillary gel electrophoresis.  相似文献