Mechanische Fruchtbehangsregulierung verringerte den Junifruchtfall und verbesserte die Fruchtqualität und Fruchtgröße bei ‚Conference‘- und ‚Alexander Lucas‘-Birnen     

Dipl.-Ing. Claudia Seehuber  Dr. Lutz Damerow  Achim Kunz  Dr. Michael Blanke 《Erwerbs-Obstbau》2010,52(2):45-53

In the absence of any chemicals approved for thinning pears but market demand for large particularly cv. ‘Conference’ fruit, the objective of the present study as part of a MSC thesis was to improve fruit quality i.e. achieve these fruit sizes by mechanical blossom thinning. Therefore, 18-year-old cv. ‘Conference’ pear trees, trained as super spindles, on quince A rootstock with a spacing of 4?×?0.4 m were used in Klein-Altendorf near Bonn, Germany; cv. ‘A. Lucas’ and un-thinned trees served as control. These pear trees with intense flowering were blossom-thinned on 15 April 2009 with rotor speeds of either 300 rpm or 400 rpm both at 5 km/h tractor speed with the new mechanical thinning device developed at the University of Bonn in 2004–2006. Therein, a vertical mast supports three horizontal rotors, whose vertically rotating tines remove excessive flowers; the device is mounted on the front three point hitch of the tractor. In 2009, a year with severe June drop, mechanical thinning reduced the intensity of the natural June drop with increasing rotor speed and was stronger reduced in cv. ‘A. Lucas’ (by ?38%) than in cv. ‘Conference’ (by ?27% relative to the control). In cv. ‘A. Lucas’, the natural June drop was as strong as mechanical thinning and resulted in large-sized 80 mm pear fruit in the control; mechanical thinning with 400 rpm further increased fruit mass by 16 g relative to the un-thinned control or 6 g larger than in the thinning with 300 rpm. In cv. ‘Conference’, fruit fell within the next larger fruit size class after the stronger mechanical thinning with 400 rpm at 5 km/h: the portion of pear fruit in the 75/80 mm size class was 2 fold and in the 80/85 mm size class was 6 fold that in the control. The portion of <?60, 60/65 mm and 65/70 mm fruit was halved relative to the control; the average fruit mass was increased by 40 g. Vegetative growth appeared unaffected by mechanical thinning. The risk of both over-sized fruit and over-thinning appears small, since mechanical thinning reduced the natural June drop and did not induce subsequent fruit drop. Mechanical thinning was more efficient in cv. ‘Conference’, as intended, despite more intense flowering in cv. ‘A Lucas’. An economic evaluation proved difficult, since the natural June drop particularly in cv. ‘A. Lucas’ led to large-sized fruit (80 mm) in the control, and any (mechanical) thinning is associated with lower yields (?26% in cv. ‘Conference’ and ?12% in cv. ‘A. Lucas’). Overall, the results indicate the potential of mechanical thinning as a substitute (or combination partner for chemical thinning if approved) in pear.  相似文献   

Impact of formulation and technological factors on the acrylamide content of wheat bread and bread rolls   总被引：2，自引：0，他引：2  

Achim Claus  Melanie Mongili  Georg Weisz  Andreas Schieber  Reinhold Carle 《Journal of Cereal Science》2008,47(3):546-554

This study clearly demonstrates that formulation and baking technology have strong influence on the acrylamide content in the baked products. NaCl plays an ambiguous role: Whereas low doses up to 2% lowered acrylamide by inhibition of the enzyme activities, higher addition remarkably increased the contents due to growth inhibition of the yeast. The results of previous model studies concerning the influence of cysteine could be confirmed in pilot plant experiments. Its addition to the dough resulted in significantly lower acrylamide content whereas its application to the crust proved to be ineffective. Furthermore, it was demonstrated that enzyme-bearing bakery improvers had no influence on acrylamide formation. In pilot plant experiments acrylamide was reduced with increasing fermentation time, and minimum acrylamide levels were already reached after 60 min thus avoiding flattened breads due to prolonged amylase activity. Besides formulation and fermentation also process technology is crucial. As shown by our data, reduced baking temperature and prolonged heat treatment is favorable. Furthermore, convection ovens seem to enhance acrylamide formation compared to deck oven.  相似文献   

Laparoscopic Gonadectomy in Two Intersex Warmblood Horses     

Mariana Peer  Stefanie Neuhauser  Christoph Klaus  Heidi Kuiper  Achim D. Gruber  Ottmar Distl  Christoph Lischer  Johannes Handler 《Journal of Equine Veterinary Science》2012

Two phenotypically female Warmblood horses were presented at the Clinic for Horses owing to stallion-like behavior. One mare had an enlarged clitoris, whereas the other one showed no signs of ambiguous external genitalia. In both cases, intra-abdominal testicles were removed by laparoscopy. Hormone status, cytogenetic evaluation, and histopathological examination of the gonads were performed. One animal was diagnosed as having XX disorder of sexual development; the other one, as male pseudohermaphrodite.  相似文献   

Myowater dynamics and protein secondary structural changes as affected by heating rate in three pork qualities: a combined FT-IR microspectroscopic and 1H NMR relaxometry study     

Wu Z  Bertram HC  Böcker U  Ofstad R  Kohler A 《Journal of agricultural and food chemistry》2007,55(10):3990-3997

The objective of this study was to investigate the influence of heating rate on myowater dynamics and protein secondary structures in three pork qualities by proton NMR T2 relaxation and Fourier transform infrared (FT-IR) microspectroscopy measurements. Two oven temperatures at 100 degrees C and 200 degrees C corresponding to slow and fast heating rates were applied on three pork qualities (DFD, PSE, and normal) to an internal center temperature of 65 degrees C. The fast heating induced a higher cooking loss, particularly for PSE meat. The water proton T21 distribution representing water entrapped within the myofibrillar network was influenced by heating rate and meat quality. Fast heating broadened the T21 distribution and decreased the relaxation times of the T21 peak position for three meat qualities. The changes in T21 relaxation times in meat can be interpreted in terms of chemical and diffusive exchange. FT-IR showed that fast heating caused a higher gain of random structures and aggregated beta-sheets at the expense of native alpha-helixes, and these changes dominate the fast-heating-induced broadening of T21 distribution and reduction in T21 times. Furthermore, of the three meat qualities, PSE meat had the broadest T21 distribution and the lowest T21 times for both heating rates, reflecting that the protein aggregation of PSE caused by heating is more extensive than those of DFD and normal, which is consistent with the IR data. The present study demonstrated that the changes in T2 relaxation times of water protons affected by heating rate and raw meat quality are well related to the protein secondary structural changes as probed by FT-IR microspectroscopy.  相似文献   

Single-sided and semisingle-sided NMR sensors for highly diffusive samples: application to bottled beverages     

Stork H  Gädke A  Nestle N 《Journal of agricultural and food chemistry》2006,54(15):5247-5252

Single-sided NMR sensors such as the NMR-MOUSE have been very successfully implemented for quality control applications in the rubber and polymer industries. More recently, single-sided NMR was also applied in characterization of the fat components in foods. Both industrial polymers and the fat components in food exhibit relatively low self-diffusion coefficients on the order of 5x10(-11) m2/s or lower. The application of conventional single-sided NMR to highly mobile, watery phases in foods and beverages is hampered by the strong magnetic field gradient present in standard single-sided NMR devices. In this contribution, we present both a single-sided NMR sensor with a reduced magnetic field gradient and another ("semisingle-sided") sensor design with an open sample bay using a single-sided RF coil. The latter design allows much better sensitivity without sacrificing the necessary open access needed for measurements on entire food packages such as bottles. As a first application, the sensors were used for determining the oxygen content in bottles with superoxygenated table water.  相似文献   

Organische Substanz und Benetzbarkeit von Bodenproben ‐ eine Interpretation     

Achim Ellies  Karl Heinrich Hartge  Roberto MacDonald  Carlos Ramirez 《植物养料与土壤学杂志》2003,166(1):120-123

Organic matter and wetting properties of soil samples — an interpretation Samples were taken from A horizons of Udands and Humults at four 4 sites under forest and pasture vegetation in Southern Chile. Aggregates of 4—6 and 10—12 mm diameter were obtained by sieving and separated into aggregate surface and core fraction by peeling. The fraction 38—63 μm was separated by sieving. Organic matter was determined in all samples. Wetting angles were determined by direct reading at drops of saturated KCl solution on a layer of particles fixed on microscope glass slides by double‐sided adhesive tape. Values were correlated with contents of organic matter. The results showed an increase of wetting angles with increasing percentage of organic matter in the overall samples as well as in all separate groups (depth, vegetation, size, and parts of aggregates). The correlations, however, were not close (r ～ 0.5), irrespective of the significance level. Wetting angles in soils are caused by combined effect of different relative amounts and properties of free organic matter particles and organic films on mineral particles.  相似文献   

Gefügeänderung bei Andosolen Südchiles als Folge der Nutzung seit der Rodung     

Karl Heinrich Hartge  Achim Ellies 《植物养料与土壤学杂志》1990,153(6):389-393

Changes in soil structure as caused by land use after clearing virgin forest Three groups of volcanic ash soils from southern Chile were investigated to evaluate the change of porosity, penetrometer resistance and packing characteristics of virgin forest soils due to different forms of land use during a variable length of time. The different forms of land use were pasture, arable land and reforestation with Pinus radiata. Afforestation tended to loosen the soil and to increase soil strength, whereas pasture use or a pasture-arable land rotation showed severe compressions. Compressions, as noticed in the ash soils under study, appeared to be more pronounced than is generally observed in mineral soils.  相似文献   

Mechanische Druckfortpflanzung in vulkanischen Aschenböden bei unterschiedlicher Bewirtschaftungsweise     

Achim Ellies  Rainer Horn 《植物养料与土壤学杂志》1996,159(2):113-120

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Verschiedene Materialien zur Lichtreflexion in Apfelanlagen unter Hagelnetzen zur Verbesserung der Fruchtqualit?t und besonders der Fruchtfarbe bei ?Gala??     

Tobias Meinhold  Lutz Damerow  Achim Kunz  Michael Blanke 《Erwerbs-Obstbau》2011,52(3-4):117-128

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Institutional change in the forestry sector—The explanatory potential of New Institutional Economics     

Achim Schlüter   《Forest Policy and Economics》2007,9(8):1090-1099

Due to a changed economic situation and due to a changed understanding about the role of the state in governing forest resources, there is currently a formal institutional change under way in various European countries. It will have far-reaching consequences for the mode of governance of forests. Institutions, as the rules of game, seem to be in need of change on all levels: international and national laws, collective choice arrangements, such as forest associations or contracts between economic actors. Within economics, New Institutional Economics (NIE) is the body of literature dealing with the rules of the game. This paper focuses on those theories within NIE that try to explain them.This paper focuses on those theories within NIE that try to explain institutional change and looks for their applicability to the forestry sector. The paper argues that, because of particular characteristics of the forestry sector, we should avoid applying a too simplified (neoclassical) version of the theory that relies mainly on the explanatory power of competition, transaction costs, efficiency and (bounded) rational actors. Instead, we should extend this theory and analyse carefully the ideologies – a term introduced by Douglas North into NIE – prevailing in the different actors' minds in order to understand the driving forces of institutional change. Ideology comprises on the one hand the mental models individuals use to explain the world and on the other hand the normative value judgements they use for knowing how the world “should be”.  相似文献