Broodstock spawning and larviculture of whiting (Merlangius merlangus L.) reared in captivity

In recent years, an increasing interest in the farming of marine ‘white’ fish, such as cod, has been observed in the aquaculture industry. One species being considered for aquaculture development is whiting (Merlangius merlangus L.). With little data being available on the domestication of this species, our study aimed to characterize spawning behaviour and rhythmicity in captive broodstock and provide original data on egg incubation, embryonic development and larval rearing. The results observed through video recording showed that spawning mainly occurred at night with active courtship behaviour. Daily egg batches were collected from two separate spawning seasons, with an average fertilization success declining from 77% to 53%. Time to hatch was inversely related to the incubation temperature and occurred after 78 degree‐days (9 days at 8 °C), with emerging larvae ranging in size from 3.3 to 3.46 mm total length and hatch success ranging from 48.3% to 99.9%. In comparison with a clear water environment, a green water regime during the first days of larval rearing significantly improved larval growth and survival. These results are the first to describe spawning activity, early development and larval performances in whiting and are promising for the potential future development of whiting aquaculture.     

Inverse Modeling to Quantify Irrigation System Characteristics and Operational Management

Remotely sensed (RS) data is a major source to obtain spatialdata required for hydrological models. The challenge for thefuture is to obtain besides the more direct observable data(landcover, leaf area index, digital elevation model andevapotranspiration), non-visible data such as soilcharacteristics, groundwater depth and irrigation practices.In this study we have explore the option of using inversemodeling to obtain these non-RS-visible data. For a commandarea in Haryana, India, we applied for the 2000–2001 rabiseason a RS-GIS-combined inverse modeling approach to derivenon-RS-visible data required in the regional application ofhydrological models. A Genetic Algorithm loaded stochasticphysically based soil-water-atmosphere-plant model (SWAP) wasdeveloped for the inverse problem and used in the study. Theresults showed good agreement with the inventoried data suchas soil hydraulic properties, sowing dates, groundwaterdepths, irrigation practices and water quality. The deriveddata could be used to predict the state of the system at anytime in the cropping season, which can be used to evaluateoperational management strategies.     

Determination of the activity of acidic phytate-degrading enzymes in cereal seeds

Five different methods were compared to elucidate the total activity of the acidic phytate-degrading enzymes present in the seeds of rye, wheat, and barley. Phytate-degrading activity was studied at pH 5.0 by quantifying the liberated phosphate. Rye showed the highest acid phytate-degrading activity among the cereals studied. Using an aqueous extract, only 30-50% of the activity was found (rye, 3443 mU g(-1) of grain; wheat, 1026 mU g(-1) of grain; barley, 1032 mU g(-1) of grain) compared to that found by the direct incubation of the dry-milled cereal grains in a buffered phytate-containing solution (rye, 6752 mU g(-1) of grain; wheat, 2931 mU g(-1) of grain; barley, 2093 mU g(-1) of grain). Extending the extraction time resulted in an increase in extractable phytate-degrading activity by, at maximum, 10-15%. Extraction of phytate-degrading activity is strongly enhanced in the presence of Triton X-100 and the protease inhibitor phenylmethylsulfonyl fluoride (rye, 6536 mU g(-1) of grain; wheat, 2873 mU g(-1) of grain; barley, 2023 mU g(-1) of grain), suggesting at least a partial association with membrane structures and a degradation by proteolytic activity during extraction. In addition, it was shown that determining phytate-degrading activity by quantification of the liberated inorganic phosphate is more robust and precise than determining phytate-degrading activity by quantification of the residual phytate.     

Novel application of square-wave adsorptive-stripping voltammetry for the determination of xanthohumol in spent hops

This paper reports the development of a novel electrochemical assay for xanthohumol (XN) by square-wave adsorptive-stripping voltammetry (SWAdSV) with a hanging mercury drop electrode. The method showed good repeatability (CV < 2%) and linearity (between 10 and 250 μg L(-1)), as well as suitable limits of detection (2.6 μg L(-1)) and quantification (8.8 μg L(-1)). The method was applied for the quantification of this compound in spent hops, and the results obtained were compared with the HPLC-UV method. XN contents determined by the SWAdSV method were 16 ± 1 and 100 ± 4 μg L(-1) for aqueous and methanolic extracts, respectively. The developed new methodology considerably reduces the analysis time, approximately from 25 min (HPLC-UV method) to 7 min, enabling a high sample throughput. In addition, the detection and quantification limits were approximately 5-fold lower than those obtained with the chromatographic method.     

Microbial activity and community structure in two drained fen soils in the Ljubljana Marsh

Fen peatlands are specific wetland ecosystems containing high soil organic carbon (SOC). There is a general lack of knowledge about the microbial communities that abound in these systems. We examined the microbial activity and community structure in two fen soils differing in SOC content sampled from the Ljubljana Marsh under different seasonal conditions. Substrate-induced respiration and dehydrogenase activity were used as indicators of total microbial activity. Both methods indicated higher microbial activities in the fen soil with the higher SOC content on all dates of sampling. To determine whether the differences in microbial activity were associated with differences in the microbial community structures, terminal restriction fragment length polymorphism (T-RFLP) of bacterial 16S rRNA genes was performed. Comparison of the T-RFLP profiles revealed very similar community structures in both fens and in the two seasonal extremes investigated. This suggested a stable community structure in the two fens, which is not affected by the SOC content or seasonal variation. In addition, a bacterial 16S ribosomal RNA gene based clone library was prepared from the fen soil with the higher SOC content. Out of 114 clones analysed, approximately 53% belonged to the Proteobacteria, 23% to the Acidobacteria, 21% to a variety of other taxa, and less than 3% were affiliated with the Firmicutes.     

监测饲料及其原料以消除霉菌毒素的影响

由于霉菌毒素是一类无色无臭无味的物质,所以测定饲料原料和饲料成品以监测霉菌毒素的污染是非常重要的. 霉菌毒素这一术语源自希腊语单词"mycos"和"toxikon",是指在各种各样环境条件下由真菌产生的次生有毒代谢产物.     

Parallel patterns of evolution in the genomes and transcriptomes of humans and chimpanzees

The determination of the chimpanzee genome sequence provides a means to study both structural and functional aspects of the evolution of the human genome. Here we compare humans and chimpanzees with respect to differences in expression levels and protein-coding sequences for genes active in brain, heart, liver, kidney, and testis. We find that the patterns of differences in gene expression and gene sequences are markedly similar. In particular, there is a gradation of selective constraints among the tissues so that the brain shows the least differences between the species whereas liver shows the most. Furthermore, expression levels as well as amino acid sequences of genes active in more tissues have diverged less between the species than have genes active in fewer tissues. In general, these patterns are consistent with a model of neutral evolution with negative selection. However, for X-chromosomal genes expressed in testis, patterns suggestive of positive selection on sequence changes as well as expression changes are seen. Furthermore, although genes expressed in the brain have changed less than have genes expressed in other tissues, in agreement with previous work we find that genes active in brain have accumulated more changes on the human than on the chimpanzee lineage.     

3 TESLA MAGNETIC RESONANCE IMAGING OF THE OCCIPITOATLANTOAXIAL REGION IN THE NORMAL HORSE

The aim of this study was to describe the appearance of the ligamentous structures of the occipitoatlantoaxial (OAA) region in the normal horse by 3 tesla (3T) magnetic resonance imaging (MRI). The MRI images of the longitudinal odontoid ligament, tectorial membrane, dorsal and ventral atlantoaxial ligaments, dorsal atlantooccipital membrane with its reinforcing ligaments, and the lateral atlantooccipital ligaments of 10 horse cadavers were evaluated. All ligaments and membranes were identified in all planes, except for the lateral atlantooccipital ligament in the sagittal plane due to its cranioventrolateral course. All were iso to mildly hypointense to musculature of the neck in T1W with the exception of the tectorial membrane that was moderately hypointense; moderately hypointense in PD‐SPIR, and markedly hypointense (isointense to cortical bone) in T2W. The PD‐SPIR was the best sequence to identify all ligaments and membranes from their cranial and caudal attachments. The longitudinal odontoid ligament, ventral atlantoaxial ligament, and reinforcing bands of the dorsal atlantooccipital membrane presented a characteristic striped heterogeneous signal behavior thought to be due to fibrocartilaginous content. The remaining ligaments and membranes showed homogeneous signal intensity. Special anatomical features in this species such as the fan‐shaped longitudinal odontoid ligament, absence of the transverse ligament and presence of the ventral atlantoaxial ligament were documented. Ligamentous structures that stabilize the equine OAA region were described with MRI in this study and these findings could serve as an anatomic reference for those cases where instability of this region is suspected.     

Simulating the soil phosphorus dynamics of four long-term field experiments with a novel phosphorus model

Phosphorus is a nonrenewable resource, which is required for crop growth and to maintain high yields. The soil P cycle is very complex, and new model approaches can lead to a better understanding of those processes and further guide to research gaps. The objective of this study was to present a P-submodel, which has been integrated in the existing Carbon Candy Balance (CCB) model that already comprises a C and N module. The P-module is linked to the C mineralization and the associated C-pools via the C/P ratio of fresh organic material. Besides the organic P cycling, the module implies a plant-available P-pool (P_av), which is in a dynamic equilibrium with the nonavailable P-pool (P_na) that comprises the strongly sorbed and occluded P fraction. The model performance was tested and evaluated on four long-term field experiments with mineral P fertilization, farmyard manure as organic fertilizer and control plots without fertilization. The C dynamics and the P_av dynamics were modelled with overall good results. The relative RMSE for the C was below 10% for all treatments, while the relative RMSE for P_av was below 15% for most treatments. To accommodate for the rather small variety of available P-models, the presented CNP-model is designed for agricultural field sites with a relatively low data input, namely air temperature, precipitation, soil properties, yields and management practices. The CNP-model offers a low entry threshold model approach to predict the C-N and now the P dynamics of agricultural soils.     

The Static Fertilization Experiment at the Start and the End of the 20th Century

Changes of yields, nitrogen uptake on the zero plots and nitrogen balances are discussed in the course of the decades at the Static Fertilization Experiment exemplary. 1991-2000 yields of cereals on the fertilized plots were nearly 200% in comparison to 1906-1915. At potatoes and sugar beets increase of yields was smaller. In the middle of all crops 52kg/ha nitrogen were taken up on the unfertilized plots in the years 1959-2000. Since there is a balance in the soil this nitrogen can only derived from the air. On the PK plots the atmogenic nitrogen input is 6kg/ha still higher. Crops with a long vegetation period like winter wheat and sugar beets take up more atmogenic nitrogen than such with a shorter vegetation period like summer barley and potatoes. The atmogenic nitrogen input per day of vegetation period is between 0,24 (winter wheat) and 0,38 (sugar beet)kg/ha and day. Nitrogen balances of the more important variants show that nitrogen uptake is higher than nitrogen input for a long time. In comparison of the decades 1961-1970 and 1991-2000 the best effect is in the case of mineral fertilization alone, also at increasing nitrogen input at the end of the century. The reason is the optimal control of nitrogen amount and time of application. In contrast organic fertilization and nitrogen release from the organic matter you can't control with the result of more unfavourable balances.