Bodenkennwerte und Ertrage von Nährstoffmangelvarianten und nach temporärer düngung von Mangelvarianten im Thyrower Statischen Nährstoffmangelversuch

Langjährig unterlassene Kalkung führte bei mineralisch (NPK) und mit Stallmist gedüngtem Boden in den letzten 20 Versuchsjahren zu pH‐Werten von 4,2 bis 3,6. Die Relativerträge nahmen im Vergleich zur mineralischen Volldüngung (NPKCa) ab. Diese Abnahme war von der Pflanzenart abhängig und bei Sommergerste deutlicher als bei Kartoffeln und Mais. Kalkung des mit NPK gedüngten Bodens erhöhte die Erträge bei Mais bereits im ersten Jahr, bei Gerste und Kartoffeln erst nach mehreren Jahren auf das Niveau der Vergleichsvariante. Bei einer Umstellung von Stallmist auf Stallmist + NPKCa glichen sich die Erträge von Mais und Sommergerste im gleichen Jahr, bei Kartoffeln erst nach mehreren Jahren dem langjährig mit Stallmist + NPKCa gedüngten Prüfglied an.

Im langjährig ungedüngten Boden fielen pH‐Wert, K_DL und P_DL in den letzten 20 Versuchsjahren ebenfalls deutlich ab (pH 3,6 bis 4,1; K_DL 2,2 bis 5,0 und P_DL 3,5 bis 5,5 mg/100 g Boden). In deren Folge und durch N‐Mangel kam es bei Gerste zum Totalausfall und bei Mais nahezu zum Totalausfall. Bei Kartoffeln lag der Ertrag noch bei 15% der Vergleichsvariante NPKCa. Eine Düngung der Mangelparzellen mit NPKCa ließ den pH‐Wert bereits im ersten Jahr, K_DL und P_DL erst nach mehrmaliger Düngung in den anzustrebenden Bereich ansteigen. Eine Angleichung der Erträge an die Erträge des durchgehend mit NPKCa gedüngten Prüfgliedes dauerte drei bis vier Jahre.     

Languages evolve in punctuational bursts

Linguists speculate that human languages often evolve in rapid or punctuational bursts, sometimes associated with their emergence from other languages, but this phenomenon has never been demonstrated. We used vocabulary data from three of the world's major language groups-Bantu, Indo-European, and Austronesian-to show that 10 to 33% of the overall vocabulary differences among these languages arose from rapid bursts of change associated with language-splitting events. Our findings identify a general tendency for increased rates of linguistic evolution in fledgling languages, perhaps arising from a linguistic founder effect or a desire to establish a distinct social identity.     

Akkumulation und Mobilisation von Phosphaten in einer Schwarzerde im Statischen Dauerversuch Lauchstädt - Betrachtung der P-Bilanz nach 84 Versuchsjahren

Accumulation and Mobilisation of Phosphate in Haplic chernozem of the Static Long-Term Experiment at Lauchstädt - Consideration of the P-Balance after 84 Years Phosphate balance was calculated and various soil P parameters of a long-term field experiment at Lauchstädt were determined in which mineral fertilizer and farm yard manure were applied in rates of 0 to 54 kg P/ha/year. The various fertilizer treatments resulted in a considerable variation of the P balance sheet ranging from -738 to 2652 kg P/ha. This implies that 59 % of the applied P (cumulated maximum 4477 kgP/ha) remained in the soil, the rest was taken up by crops. Assuming a balanced P supply in which crop P uptake equaled the P fertilizer rate, a rate of 12, 9 kgP/ha/year would be required. This rate was approximately calculated for the various treatments having received farm yard manure. Phosphate mobilized from the soil (up to 738 kg P/ha) was related to factors which had an impact on crop yield. The decrease of total P in the upper soil layer (0 to 25 cm) was lower than the cumulative P uptake of crops. It is therefore assumed that a considerable proportion of P taken up by crops came from the subsoil. The change in the P balance sheet obtained during 84 years was clearly reflected by various soil parameters including the maximum P adsorption capacity which was highest in the treatment with the largest P deficit (NK treatment).     

Changes in the heart beat of puppies in the first twelve weeks of life

In 37 healthy pups and seven pups with congenital pulmonic stenosis ECG were recorded and the heart rate determined. Between the first week of life in healthy pups (mean = 230/min) and the twelfth week of life the heart rate in both groups at six weeks was 195/min and 180/min. At the end of the investigation the averaged heart rate was 167/min or 166/min respectively. In single weeks during the investigation a slightly increased heart rate occurred in a few dogs between the fourth and sixth week of life owing to an increased restlessness during this time span. The heart rate of newborn pups at the first day (mean = 215/min) was a little lower than the average in the first week of life.     

Hypertrophy and physiological death of equine chondrocytes in vitro

REASON FOR PERFORMING STUDY: Equine osteochondrosis results from a failure of endochondral ossification during skeletal growth. Endochondral ossification involves chondrocyte proliferation, hypertrophy and death. Until recently no culture system was available to study these processes in equine chondrocytes. OBJECTIVE: To optimise an in vitro model in which equine chondrocytes can be induced to undergo hypertrophy and physiological death as seen in vivo. METHODS: Chondrocytes isolated from fetal or older (neonatal, growing and mature) horses were cultured as pellets in 10% fetal calf serum (FCS) or 10% horse serum (HS). The pellets were examined by light and electron microscopy. Total RNA was extracted from the pellets, and quantitative PCR carried out to investigate changes in expression of a number of genes regulating endochondral ossification. RESULTS: Chondrocytes from fetal foals, grown as pellets, underwent hypertrophy and died by a process morphologically similar to that seen in vivo. Chondrocytes from horses age >5 months did not undergo hypertrophy in pellet culture. They formed intramembranous inclusion bodies and the cultures included cells of osteoblastic appearance. Pellets from neonatal foals cultured in FCS resembled pellets from older horses, however pellets grown in HS underwent hypertrophy but contained inclusion bodies. Chondrocytes from fetal foals formed a typical cartilage-like tissue grossly and histologically, and expressed the cartilage markers collagen type II and aggrecan mRNA. Expression of Sox9, collagen type II, Runx2, matrix metalloproteinase-13 and connective tissue growth factor mRNA increased at different times in culture. Expression of fibroblast growth factor receptor-3 and vascular endothelial growth factor mRNA decreased with time in culture. CONCLUSIONS: Freshly isolated cells from fetal growth cartilage cultured as pellets provide optimal conditions for studying hypertrophy and death of equine chondrocytes. POTENTIAL RELEVANCE: This culture system should greatly assist laboratory studies aimed at elucidating the pathogenesis of osteochondrosis.     

The influence of the herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA) on the mineralization of litter-derived alkanes and the abundance of the alkane monooxygenase gene (alkB) in the detritusphere of Pisum sativum (L.)

In the present study, the temporal and spatial variation of the abundance of the alkane monooxygenase gene alkB and 16S rRNA genes in different soil compartments was analysed in the presence or absence of 2-methyl-4-chlorophenoxyacetic acid (MCPA) after the addition of pea litter to soil in a microcosm study. Samples were analysed shortly after litter addition (T0) and 1?week (T1), 3?weeks (T3) and 6?weeks (T6) after the addition of litter. In addition also, the quantity and quality of litter-derived alkanes was analysed and measured. The results revealed a fast and complete degradation of MCPA in all compartments throughout the experiment. Nevertheless, significant changes in the distribution patterns of short- and middle-chained alkanes suggest an interaction of MCPA and alkane degradation. alkB gene copy numbers were highly influenced by the time point of analysis and by the investigated soil compartment. Overall, an increase in alkB gene copy numbers from T0 to T3 was visible in the upper soil compartments whereas a decrease compared to T0 was measured in the deeper soil compartments. MCPA addition resulted in an increase of alkB abundance at T6. Gene copy numbers of 16S rRNA were not influenced by sampling time and soil compartment. In contrast to the control treatments, a slight increase in 16S rRNA gene copy numbers was visible at T1 and T3 compared to T0 in all soil compartments.     

Adsorption of the Bacillus thuringiensis toxin (Cry1Ab) on Na‐montmorillonite and on the clay fractions of different soils

The adsorption of the toxin from Bacillus thuringiensis (Bt‐toxin), which is synthesized in genetically modified maize, on sterilized Na‐montmorillonite and on H₂O₂‐treated and untreated clay fractions of three soils from different sites were studied. All adsorption isotherms can be described by a linear isotherm. Although all clay fractions from the different soils show nearly the same mineralogical composition, we found different affinities ranging from k = 47.7 to k = 366.7 of the adsorbates for the Bt‐toxin. The H₂O₂‐treated clay fractions show no correlation between the adsorption affinity and the amount of soil organic matter. On the other hand, there is a correlation between the content of organic carbon and the adsorption affinity of the untreated clay fractions. This can be explained by the fact that due to the coatings of soil organic matter on aggregates, the Bt‐toxin polymers are not able to adsorb within the clay aggregates.