The choice of definition has a large effect on reported quantities of dead wood in boreal forest     

Ulf Söderberg  Sören Wulff  Göran Ståhl 《Scandinavian Journal of Forest Research》2014,29(3):252-258

A survey was conducted to assess the impact of the choice of definition on reported quantities of dead wood in Swedish forests, which to more than 90% are located in the boreal zone. The data collection was made on a subsample of the permanent plots of the Swedish national forest inventory. The objects included were standing dead trees and snags down to 5-cm diameter at breast height, dead lying stems and branches down to a threshold diameter of 1 cm and stumps down to a threshold diameter of 5-cm at normal stump height. Standing trees, snags and stumps were inventoried on 10-m radius circular plots while the downed objects were inventoried using both circular plots and line intersect sampling; thin objects (diameter 1–5 cm) were assessed only through line intersect sampling. The results showed that the estimated volume of dead wood was as high as 25 m³ ha^?1 when all components were included. With the standard Swedish definition, the corresponding estimate was only 10.9 m³ ha^?1, or 43% of the total value. Since definitions of dead wood vary greatly between countries we conclude that great caution must be exercised when figures are compared in connection with international reporting. For example, adding stumps to the Swedish definition would increase the amounts of dead wood from 10.9 to 15.7 m³ ha^?1, i.e. with 44%.  相似文献   

Significance of ossificated ungular cartilages regarding the performance of cold-blooded trotters     

Ulf O Hedenstr?m  Ove S Wattle 《Acta veterinaria Scandinavica》2014,56(1)

Background

Ossification of the ungular cartilages (OUC) in the foot of horses has been studied for more than 100 years. There is a high heritability of this condition but its clinical relevance has remained questionable. Nevertheless, modern equine orthopedic literature ranks OUC as one of top 10 causes of lameness in cold-blooded trotters and stallions of these breeds are excluded from breeding if they have more than mild levels of side bones. Cold-blooded trotters have been used for racing for many decades and official sports data have been available since 1923. A decreased performance is often the only obvious clinical sign noticed by trainers and owners motivating them to seek professional help from veterinarians and farriers. By comparing various performance parameters in Swedish-Norwegian cold-blooded trotters without and with different grades of OUC, we aimed to determine the clinical relevance of ossified hoof cartilages in a population of high-performance horses.Front hooves from 649 Swedish-Norwegian cold-blooded trotters were evaluated radiologically regarding OUC. Breeding index and official sports data originating from strict protocols kept by groups of officials in trotting associations was used for comparison of performance of these horses that together had competed in more than 23,000 races between 1973 and 2009. Generalized linear mixed models were used for the statistical analyses. The response variable was modeled using ordinal logistic models with a multinomial distribution and a cumulative logit link function. The horse was used as a random factor.

Results

Significant effects of gender on performance were demonstrated, but no correlations were found between different positions nor grades of ossified ungular cartilage and number of starts, running pace, race winnings, number of races completed in a regular gait.

Conclusions

Ossification of the ungular cartilages does not cause decreased performance in cold-blooded trotters and is therefore most likely not a cause of clinical or subclinical lameness in this breed. Results from this study can assist equine professionals in evaluating and interpreting the clinical relevance of radiological findings on ossified hoof cartilage among heavy and high-performing horses.  相似文献   

Phenological shifts compensate warming-induced drought stress in southern Siberian Scots pines     

Arzac  Alberto  Tychkov  Ivan  Rubtsov  Alexey  Tabakova  Maria A.  Brezhnev  Ruslan  Koshurnikova  Natalia  Knorre  Anastasia  Büntgen  Ulf 《European Journal of Forest Research》2021,140(6):1487-1498

European Journal of Forest Research - Global climate change impacts the functioning and productivity of forest ecosystems at various spatiotemporal scales across a wide range of biomes. Although...  相似文献   

Neuroscience. Illusions and perceived images in the primate brain     

Eysel UT 《Science (New York, N.Y.)》2003,302(5646):789-791

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Ecology: managing evolving fish stocks     

Jørgensen C  Enberg K  Dunlop ES  Arlinghaus R  Boukal DS  Brander K  Ernande B  Gardmark A  Johnston F  Matsumura S  Pardoe H  Raab K  Silva A  Vainikka A  Dieckmann U  Heino M  Rijnsdorp AD 《Science (New York, N.Y.)》2007,318(5854):1247-1248

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Genome-wide association analysis identifies loci for type 2 diabetes and triglyceride levels     

Diabetes Genetics Initiative of Broad Institute of Harvard  MIT  Lund University    Novartis Institutes of BioMedical Research  Saxena R  Voight BF  Lyssenko V  Burtt NP  de Bakker PI  Chen H  Roix JJ  Kathiresan S  Hirschhorn JN  Daly MJ  Hughes TE  Groop L  Altshuler D  Almgren P  Florez JC  Meyer J  Ardlie K  Bengtsson Boström K  Isomaa B  Lettre G  Lindblad U  Lyon HN  Melander O  Newton-Cheh C  Nilsson P  Orho-Melander M  Råstam L  Speliotes EK  Taskinen MR  Tuomi T  Guiducci C  Berglund A  Carlson J  Gianniny L 《Science (New York, N.Y.)》2007,316(5829):1331-1336

New strategies for prevention and treatment of type 2 diabetes (T2D) require improved insight into disease etiology. We analyzed 386,731 common single-nucleotide polymorphisms (SNPs) in 1464 patients with T2D and 1467 matched controls, each characterized for measures of glucose metabolism, lipids, obesity, and blood pressure. With collaborators (FUSION and WTCCC/UKT2D), we identified and confirmed three loci associated with T2D-in a noncoding region near CDKN2A and CDKN2B, in an intron of IGF2BP2, and an intron of CDKAL1-and replicated associations near HHEX and in SLC30A8 found by a recent whole-genome association study. We identified and confirmed association of a SNP in an intron of glucokinase regulatory protein (GCKR) with serum triglycerides. The discovery of associated variants in unsuspected genes and outside coding regions illustrates the ability of genome-wide association studies to provide potentially important clues to the pathogenesis of common diseases.  相似文献   

Fiber-optical analog of the event horizon     

Philbin TG  Kuklewicz C  Robertson S  Hill S  König F  Leonhardt U 《Science (New York, N.Y.)》2008,319(5868):1367-1370

The physics at the event horizon resembles the behavior of waves in moving media. Horizons are formed where the local speed of the medium exceeds the wave velocity. We used ultrashort pulses in microstructured optical fibers to demonstrate the formation of an artificial event horizon in optics. We observed a classical optical effect: the blue-shifting of light at a white-hole horizon. We also showed by theoretical calculations that such a system is capable of probing the quantum effects of horizons, in particular Hawking radiation.  相似文献   

Nitrogen use efficiency of microalgae application in wheat compared to mineral fertilizer     

Flora Mückschel  Elijah Ollo  Stefanie P. Glaeser  Rolf Düring  Feng Yan  Hermann Velten  Ulf Theilen  Michael Frei 《植物养料与土壤学杂志》2023,186(5):522-531

Background

Wastewater from sewage treatment plants contains high levels of nutrients, which can be used for plant nutrition. Classical wastewater treatment plants use complex microbial consortia of autotrophic and heterotrophic microorganisms for biological wastewater treatment. Certain autotrophic microalgae (e.g., species of the genera Chlorella, Scenedesmus, and Pediastrum) accumulate nutrients from wastewater very effectively.

Aims

We investigated the potential of microalgae biomass obtained from a prototype wastewater treatment plant as a source of nutrients for crops, focusing on nitrogen.

Methods

We provided wheat plants with different levels of algae biomass equivalent to 60, 120, and 180 kg N per hectare or with mineral fertilizer (N, P, and K) equivalent to the amounts contained in the algal biomass. Physiological and phenotypic traits were measured during growth, including vegetation indices, photosynthetic performance, growth, and nitrogen use efficiency (NUE). In addition, the adundances of Bacteria, Archaea and fungi and genes of ammonium oxidizing Bacteria and Archaea were determined in the rhizosphere of differently fertilized plants.

Results

Microalgal application at fertilizer levels of 120 and 180 kg N ha^–1 showed significantly improved physiological performance, growth, yield and nutrient uptake compared to the unfertilized control. Nevertheless, their yields and NUE were lower than with the application of equal amounts of mineral fertilization, while the adundance of rhizosphere microbes and ammonia-oxidizing microorganisms were not significantly affected.

Conclusions

Microalgae from wastewater treatments form a suitable source of organic fertilizer for wheat plants with only moderate reductions in N use efficiency compared to mineral fertilizer.  相似文献   

Electrical stunning of farmed Atlantic cod Gadus morhua L.: a comparison of an industrial and experimental method     

Hanne Digre  Ulf Erikson  Ekrem Misimi  Bert Lambooij  Hans Van De Vis 《Aquaculture Research》2010,41(8):1190-1202

An industrial and experimental electrical method for stunning farmed Atlantic cod in air and seawater (SW), respectively, were compared. The impacts of sedation with AQUI‐S^? and exercise to exhaustion before electrical stunning were also assessed to monitor the possible depletion of rested muscle energy levels by electrical stunning. Stress (blood glucose, haematocrit, muscle pH, muscle excitability, high‐energy phosphates and rigor mortis) and flesh quality (fillet texture, colour, liquid leakage (LL), gaping, residual blood and K‐value) were assessed. For the industrial stunning method, an average of 41 V, 0.2 A dc was applied to individual cod for 18–27 s. For the SW method, a bipolar square wave current (170 Hz, 33% duty cycle) was applied for 5 s. After stunning, recovery was prevented by exsanguination in chilled SW. There were no differences (P>0.05) between the two stunning methods except for a higher ultimate fillet pH for cod stunned in air 8 days postmortem. Exercise before stunning depleted muscle energy levels at slaughter, increased LL and fillets had redder and darker flesh after storage on ice for 8 days. Electrical stunning (in air) of AQUI‐S^?‐treated fish partly depleted muscle energy levels (pH 7.3, ATP 18.7 μmol g^?1, PCr 70.1 μmol g^?1). However, flesh quality was not affected. Unless pre‐rigor filleting is the chosen processing strategy, electrical stunning of cod seems to be a promising stunning method.  相似文献