Effekte moderner Verfahren der Bodenbewirtschaftung auf die Aktivität epigäischer Raubarthropoden     

Christa Volkmar  Marita Lübke-Al Hussein  Thomas Kreuter 《Gesunde Pflanzen》2003,55(2):40-45

  相似文献   

The domestic animal in heraldry; Part 3, the horse     

Mache C 《Historia medicinae veterinariae》2003,28(3):84-88

The author presents in her paper the historical background of the heraldic. In the coming four papers she will discuss the use and position of different domestic animals in heraldic.  相似文献   

Ticks and tick borne pathogens in domestic animals in the Netherlands     

Bodaan C  Nihof AM  Postigo M  Nieuwenhuijs H  Opsteegh M  Franssen L  Jebbink F  Jansen S  Jongejan F 《Tijdschrift voor diergeneeskunde》2007,132(13):517-523

  相似文献   

Influence of soil temperature and soil compaction on growth and P uptake of sugar beet     

Christa Hoffmann  Albrecht Jungk 《植物养料与土壤学杂志》1996,159(3):263-270

Sugar beet growth is often impaired by cold and compacted soil. The aim of this study was to determine the effect of soil temperature and soil compaction on the growth and function of sugar beet roots. For this purpose a pot experiment with sugar beet (Beta vulgaris) was conducted in a growth chamber in which the soil temperature was kept constant either at 10°C or 20°C and air temperature at 20°C. The soil was uncompacted (1.30 g cm^?3) or compacted to a bulk density of 1.65 g cm^?3. In order to find out whether growth restriction was caused by insufficient P supply of the plant the experiment was run without and with P application (300 mg per kg soil). Root growth was much smaller at 10°C compared to 20°C, whereas root/shoot ratio was not affected by soil temperature. Hence, root and shoot growth was inhibited to the same extent. P content of the plants was not reduced, neither by cold nor by compacted soil, although parameters of acquisition such as root length and morphological root properties were altered. Soil temperature strongly affected P influx, whereas compaction did not. The calculation with a simulation model showed that at 10°C soil temperature the predicted P uptake of the plants agreed with the measured P uptake irrespective of compaction and P application. However, at 20°C the model underestimated the P influx at low soil P availability even if allowance was made for root hairs. It is concluded that under conditions of high shoot P demand and low P availability in soil P has been mobilized by mechanisms not taken into account by the model.  相似文献   

Geomagnetic polarity change and faunal extinction in the southern ocean   总被引：1，自引：0，他引：1  

Watkins ND  Goodell HG 《Science (New York, N.Y.)》1967,156(3778):1083-1087

Paleomnlagnietic polarity changes have been detected in nine deep-sea sedimentary cores (from the Pacific-Antarctic Basin) in which an extinction horizon of a radiolarian assemblage was previously independently determined. The depths of the polarity change 0.7 million years ago and the faunal boundary are closely correlated, confirming that the faunal extinction was locally virtually synchronous. Although the reason for the faunal extinction is unknown. the possibility of causal relationships between faunal extinction and factors directly involved with sedimentation rate, sedimentation rate variation, and sediment type appears to be excluded.  相似文献   

A predator unmasked: life cycle of Bdellovibrio bacteriovorus from a genomic perspective     

Rendulic S  Jagtap P  Rosinus A  Eppinger M  Baar C  Lanz C  Keller H  Lambert C  Evans KJ  Goesmann A  Meyer F  Sockett RE  Schuster SC 《Science (New York, N.Y.)》2004,303(5658):689-692

Predatory bacteria remain molecularly enigmatic, despite their presence in many microbial communities. Here we report the complete genome of Bdellovibrio bacteriovorus HD100, a predatory Gram-negative bacterium that invades and consumes other Gram-negative bacteria. Its surprisingly large genome shows no evidence of recent gene transfer from its prey. A plethora of paralogous gene families coding for enzymes, such as hydrolases and transporters, are used throughout the life cycle of B. bacteriovorus for prey entry, prey killing, and the uptake of complex molecules.  相似文献   

UNIFORMITY OF THE PAIN THRESHOLD IN MAN     

Schumacher GA  Goodell H  Hardy JD  Wolff HG 《Science (New York, N.Y.)》1940,92(2379):110-112

  相似文献   

Failure of bone marrow cells to transdifferentiate into neural cells in vivo     

Castro RF  Jackson KA  Goodell MA  Robertson CS  Liu H  Shine HD 《Science (New York, N.Y.)》2002,297(5585):1299

  相似文献   

Complex multicolor tilings and critical phenomena in tetraphilic liquid crystals     

Zeng X  Kieffer R  Glettner B  Nürnberger C  Liu F  Pelz K  Prehm M  Baumeister U  Hahn H  Lang H  Gehring GA  Weber CH  Hobbs JK  Tschierske C  Ungar G 《Science (New York, N.Y.)》2011,331(6022):1302-1306

T-shaped molecules with a rod-like aromatic core and a flexible side chain form liquid crystal honeycombs with aromatic cell walls and a cell interior filled with the side chains. Here, we show how the addition of a second chain, incompatible with the first (X-shaped molecules), can form honeycombs with highly complex tiling patterns, with cells of up to five different compositions ("colors") and polygonal shapes. The complexity is caused by the inability of the side chains to separate cleanly because of geometric frustration. Furthermore, a thermoreversible transition was observed between a multicolor (phase-separated) and a single-color (mixed) honeycomb phase. This is analogous to the Curie transition in simple and frustrated ferro- and antiferromagnets; here spin flips are replaced by 180° reorientations of the molecules.  相似文献   

Erratum To: Susceptibility of winter wheat cultivars to wheat ear insects in Central Germany     

Nawal Gaafar  Christa Volkmar  Hilmar Cöster  Joachim Spilke 《Gesunde Pflanzen》2011,84(1):49

  相似文献