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Tiebel Katharina Huth Franka Frischbier Nico Wagner Sven 《European Journal of Forest Research》2021,140(5):1299-1299
European Journal of Forest Research - The article “Restrictions on natural regeneration of storm-felled spruce sites by silver birch (Betula pendula Roth) through limitations in... 相似文献
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Absorption of calcium fumarate salts is equivalent to other calcium salts when measured in the rat model 总被引：3，自引：0，他引：3
Weaver CM Martin BR Costa NM Saleeb FZ Huth PJ 《Journal of agricultural and food chemistry》2002,50(17):4974-4975
Calcium absorption from fumarate salts (calcium fumarate and calcium malate fumarate), which have recently been considered for use as sources for food and beverage enrichment, was compared to that from calcium citrate malate, calcium citrate, and calcium carbonate. Salts were instrinsically labeled with 45Ca and orally administered to Sprague-Dawley rats. Fractional absorption of calcium from each salt was determined using the femur uptake model. Fractional absorption from the five salts (0.30-0.27) was not significantly different (p > 0.05). Thus, when measured in the rat model, calcium from calcium fumarate and calcium malate fumarate is absorbed equally well as compared to other salts, which are common calcium sources in many foods, beverages, and supplements. 相似文献
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F E McDonough F H Steinke G Sarwar B O Eggum R Bressani P J Huth W E Barbeau G V Mitchell J G Phillips 《Journal of the Association of Official Analytical Chemists》1990,73(5):801-805
Eight laboratories participated in a collaborative study to estimate precision of a standardized rat assay for determining true protein digestibility in selected animal, fish, and cereal products. Each of 7 test protein sources (casein, tuna fish, macaroni/cheese, pea protein concentrate, rolled oats, pinto beans, and nonfat dried milk) was fed as the sole source of protein at a 10% protein level in mixed diets. Each diet was fed to 2 replicate groups of 4 rats each for a 4-day acclimation period and a 5-day balance period. Mean digestibilities ranged from 98.6% for casein to 72.6% for pinto beans. Repeatability standard deviations ranged from 0.5 to 2.0%; the mean relative standard deviation for repeatability was 0.9% (range 0.5-2.8%). Reproducibility standard deviations ranged from 1.2 to 3.2%, and the mean relative standard deviation for reproducibility was 2.4% (range 1.3-4.4%). The method has been approved interim official first action for determining true protein digestibility in foods and ingredients. 相似文献
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Tsivion D Schvartzman M Popovitz-Biro R von Huth P Joselevich E 《Science (New York, N.Y.)》2011,333(6045):1003-1007
The large-scale assembly of nanowires with controlled orientation on surfaces remains one challenge preventing their integration into practical devices. We report the vapor-liquid-solid growth of aligned, millimeter-long, horizontal GaN nanowires with controlled crystallographic orientations on different planes of sapphire. The growth directions, crystallographic orientation, and faceting of the nanowires vary with each surface orientation, as determined by their epitaxial relationship with the substrate, as well as by a graphoepitaxial effect that guides their growth along surface steps and grooves. Despite their interaction with the surface, these horizontally grown nanowires display few structural defects, exhibiting optical and electronic properties comparable to those of vertically grown nanowires. This paves the way to highly controlled nanowire structures with potential applications not available by other means. 相似文献
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An accurate and management sensitive simulation model for tile-drained Midwestern soils is needed to optimize the use of agricultural management practices (e.g., winter cover crops) to reduce nitrate leaching without adversely affecting corn yield. Our objectives were to enhance the Agricultural Production Systems Simulator (APSIM) for tile drainage, test the modified model for several management scenarios, and then predict nitrate leaching with and without winter wheat cover crop. Twelve years of data (1990-2001) from northeast Iowa were used for model testing. Management scenarios included continuous corn and corn-soybean rotations with single or split N applications. For 38 of 44 observations, yearly drain flow was simulated within 50 mm of observed for low drainage (< 100 mm) or within 30% of observed for high drain flow. Corn yield was simulated within 1500 kg/ha for 12 of 24 observations. For 30 of 45 observations yearly nitrate-N loss in tile drains was simulated within 10 kg N/ha for low nitrate-N loss (< 20 kg N/ha) or within 30% of observed for high nitrate-N loss. Several of the poor yield and nitrate-N loss predictions appear related to poor N-uptake simulations. The model accurately predicted greater corn yield under split application (140-190 kg N/ha) compared to single 110 kg N/ha application and higher drainage and nitrate-N loss under continuous corn compared to corn/soybean rotations. A winter wheat cover crop was predicted to reduce nitrate-N loss 38% (341 vs. 537 kg N/ha with and without cover) under 41-years of corn-soybean rotations and 150 kg N/ha applied to corn. These results suggest that the modified APSIM model is a promising tool to help estimate the relative effect of alternative management practices under fluctuating high water tables. 相似文献
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Huth C Russke A Alsleben B Hamann H Distl O 《Berliner und Münchener tier?rztliche Wochenschrift》2004,117(7-8):316-326
In 58 female calves of the three breeds German Holstein (GH), German Brown (GB) and German Red (GR) the body weight and height were determined at the age of 79 to 188 days. At the right front limb and the left hind limb the following claw measurements were taken: dorsal border length, diagonal length, heel length and height, angle of the dorsal border and hardness of the claw horn. Furthermore, the punctual pressure under the medial and the lateral claw of the right front limb and the left hind limb were determined using an electronic measuring system. The GH calves weighing 136.8 kg were heavier than GB, which was the tallest breed with 106.2 cm height at the sacral bone. GR calves were the smallest (99.1 cm) and weighed 121.1 kg. The length of the diagonal and the angle of the dorsal border were smaller at the hind limb of all breeds which resulted in a smaller area of ground surface for the claw of this limb. The GR calves had the longest and flattest claws. The GB showed the highest pressures per cm2 at the front limb with 25.6 N/cm2 under both claws as well as at the hind limb with 26.7 N/cm2. The AR had the smallest pressure load with 20.8 N/cm2 at the front limb and 20.2 N/cm2 at the hind limb. The animals showed a larger relative weight load and area of ground surface on the medial claws of the front and hind limbs than on the lateral claws. The highest pressures were found underneath the rear part of the medial claw in all breeds. GB calves showed the highest average pressures (33.3 N/cm2 at the front limb) while GR calves had the lowest (26.3 N/cm2 at the hind limb). GR calves had the highest claw hardness at all measuring positions. 相似文献
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Hörz F Bastien R Borg J Bradley JP Bridges JC Brownlee DE Burchell MJ Chi M Cintala MJ Dai ZR Djouadi Z Dominguez G Economou TE Fairey SA Floss C Franchi IA Graham GA Green SF Heck P Hoppe P Huth J Ishii H Kearsley AT Kissel J Leitner J Leroux H Marhas K Messenger K Schwandt CS See TH Snead C Stadermann FJ Stephan T Stroud R Teslich N Trigo-Rodríguez JM Tuzzolino AJ Troadec D Tsou P Warren J Westphal A Wozniakiewicz P Wright I Zinner E 《Science (New York, N.Y.)》2006,314(5806):1716-1719
Particles emanating from comet 81P/Wild 2 collided with the Stardust spacecraft at 6.1 kilometers per second, producing hypervelocity impact features on the collector surfaces that were returned to Earth. The morphologies of these surprisingly diverse features were created by particles varying from dense mineral grains to loosely bound, polymineralic aggregates ranging from tens of nanometers to hundreds of micrometers in size. The cumulative size distribution of Wild 2 dust is shallower than that of comet Halley, yet steeper than that of comet Grigg-Skjellerup. 相似文献
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Context
Field inventory plots which usually have small sizes of around 0.25–1 ha can only represent a sample of the much larger surrounding forest landscape. Based on airborne laser scanning (LiDAR) it has been shown for tropical forests that the bias in the selection of small field plots may hamper the extrapolation of structural forest attributes to larger spatial scales.Objectives
We conducted a LiDAR study on tropical montane forest and evaluated the representativeness of chosen inventory plots with respect to key structural attributes.Methods
We used six forest inventory and their surrounding landscape plots on Mount Kilimanjaro in Tanzania and analyzed the similarities for mean top-of-canopy height (TCH), aboveground biomass (AGB), gap fraction, and leaf-area index (LAI). We also analyzed the similarity in gap-size frequencies for the landscape plots.Results
Mean biases between inventory and landscape plots were large reaching as much as 77% for gap fraction, 22% for LAI or 15% for AGB. Despite spatial heterogeneity of the landscape, gap-size frequency distributions were remarkably similar between the landscape plots.Conclusions
The study indicates that biases in field studies of forest structure may be strong. Even when mean values were similar between inventory and landscape plots, the mostly non-normally distributed probability densities of the forest variable indicated a considerable sampling error of the small field plot to approximate the forest variable in the surrounding landscape. This poses difficulties for the spatial extrapolation of forest structural attributes and for assessing biomass or carbon fluxes at larger regional scales.10.
Seedlings of the native Australian tree species Acacia holosericea, Casuarina cunninghamiana, Eucalyptus argophloia, E. camaldulensis
and Melaleuca bracteata, were raised in nursery containers which were coated with CuCO3 (50 g l-1, in a water-based paint solution) or left uncoated for three months. Seedling growth of all species in the nursery was generally
less in treated containers, although differences were relatively small. More importantly, CuCO3 treatment reduced the occurrence of lateral roots growing down or coiling around container walls for both three- and six-month-old
seedlings. Twenty-four months after planting both three- and six-month-old seedlings on a semiarid site in subtropical southeast
Queensland, there was no effect of CuCO3 treatment on height or basal diameter development of seedlings. However, sample excavations of root systems showed that the
poor root morphology exhibited by untreated seedlings when in the nursery had persisted in the field. As such poor root form
has the potential to reduce tree growth and wind firmness in the longer term, these results suggest that chemical root-pruning
is a helpful nursery practice when raising seedlings for dryland afforestation, and in circumstances where it may be necessary
to retain seedlings in the nursery for longer than normal to take advantage of infrequent rainfall events.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献