No adverse effect of genetically modified antifungal wheat on decomposition dynamics and the soil fauna community - a field study

The cultivation of genetically modified (GM) plants has raised several environmental concerns. One of these concerns regards non-target soil fauna organisms, which play an important role in the decomposition of organic matter and hence are largely exposed to GM plant residues. Soil fauna may be directly affected by transgene products or indirectly by pleiotropic effects such as a modified plant metabolism. Thus, ecosystem services and functioning might be affected negatively. In a litterbag experiment in the field we analysed the decomposition process and the soil fauna community involved. Therefore, we used four experimental GM wheat varieties, two with a race-specific antifungal resistance against powdery mildew (Pm3b) and two with an unspecific antifungal resistance based on the expression of chitinase and glucanase. We compared them with two non-GM isolines and six conventional cereal varieties. To elucidate the mechanisms that cause differences in plant decomposition, structural plant components (i.e. C:N ratio, lignin, cellulose, hemicellulose) were examined and soil properties, temperature and precipitation were monitored. The most frequent taxa extracted from decaying plant material were mites (Cryptostigmata, Gamasina and Uropodina), springtails (Isotomidae), annelids (Enchytraeidae) and Diptera (Cecidomyiidae larvae). Despite a single significant transgenic/month interaction for Cecidomyiidae larvae, which is probably random, we detected no impact of the GM wheat on the soil fauna community. However, soil fauna differences among conventional cereal varieties were more pronounced than between GM and non-GM wheat. While leaf residue decomposition in GM and non-GM wheat was similar, differences among conventional cereals were evident. Furthermore, sampling date and location were found to greatly influence soil fauna community and decomposition processes. The results give no indication of ecologically relevant adverse effects of antifungal GM wheat on the composition and the activity of the soil fauna community.

Ruminal drinkers: endocrine and metabolic status and effects of suckling from a nipple instead of drinking from a bucket

In ruminal drinkers (RD) ingested milk is transported into the rumen and not into the abomasum. Because this is followed by changes in digestibility and absorption, we have tested whether this is associated with postprandial metabolic and endocrine changes. Unweaned, bucket-fed calves (one RD, two controls) were studied on seven farms. On d 1, after metabolic and endocrine 12-h profiles were studied, RD and one control calf were fed for 10 d by nipple, whereas the other control calf was fed by bucket. On d 11, metabolic and endocrine 12-h profiles were again studied. On d 1, mean plasma concentrations of glucose, triglycerides, urea, insulin, insulin-like growth factor-1 (IGF-1), 3,5,3'-triiodothyronine (T3), thyroxine (T4) and leptin were significantly different between RD and controls, whereas mean concentrations of non-esterified fatty acids (NEFA), total protein, albumin, and glucagon did not differ significantly among groups. In RD concentrations of glucose, NEFA, insulin, growth hormone, IGF-1, and T4 were higher, and of urea were lower on d 11 than on d 1. Glucose and insulin concentrations increased postprandially in healthy calves on d 1, but barely in RD and remained lower than in controls, and there was no rise of NEFA and triglyceride concentrations on d 1 after the initial postprandial decrease in RD, in contrast to controls. But on d 11 postprandial responses of these four traits were similar in RD and controls and urea and T4 concentrations on d 11 became normalized. However, glucose and T3 concentrations in RD on d 11 were still lower than in one or both control groups. In conclusion, various metabolic and endocrine traits in RD differed from healthy controls. Drinking by floating nipple instead of drinking from bucket for 10 d normalized several metabolic and endocrine traits in RD.

Digestive processes in ruminal drinkers characterized by means of the acetaminophen absorption test

The aim of the present study was to measure transit patterns of nutrients and the absorptive ability in ruminal drinkers (RDs) compared with healthy unweaned calves. The acetaminophen (paracetamol) absorption test was used to characterize the oroduodenal transit rate. Clinical examination and the analysis of various blood parameters provided supplementary information on digestive processes. Three unweaned bucket-fed calves (one RD and two healthy controls) each from seven Swiss dairy farms were included in the study. Measurements (tests 1 and 2) were performed twice at an interval of 10 days. Between tests, the feeding technique of the RDs and one control calf per farm was changed to feeding with a nipple instead of by bucket (without nipple). Acetaminophen appearance in the blood was delayed and reduced in RDs compared with the controls. Acid-base metabolism and several haematological and metabolic parameters differed markedly between RDs and healthy controls. The characteristics of the oroduodenal transit rate, absorptive abilities and clinical status in RDs were nearly normalised within 10 days of reconditioning.

Response of the Lateglacial fauna to climatic change

This study deals with faunal finds from the Swiss Paleolithic, especially from the Late Glacial. Faunal assemblages from archeological sites as well as off-site finds dated by scientific means are included. In the middle of the Oldest Dryas the large glacial species – mammoth, rhinoceros, cave bear, musk ox – become extinct. During the Early Bølling the last arctic species disappear, and are succeeded by animals like red deer and elk, preferring a moderate climate. From the middle of the Allerød, species typical of a denser forest (roe deer and wild boar) are very frequent.

Patterns of the Remnant Cichlid Fauna in Southern Lake Victoria. Patrones de la Fauna de Ciclidos Remanentes en el Sur del Lago Victoria

During the years 1984–1987 Lake Victoria in East Africa experienced what is probably the largest mass extinction of contemporary vertebrates. Within a decade about 200 endemic species of haplochromine cichlids disappeared. The extinctions that occurred in the 1980s have been documented predominantly on species of offshore and sub-littoral waters in the Mwanza Gulf of southern Lake Victoria. Although the littoral fauna of southern Lake Victoria had not been examined in detail, their diversity seemed less affected by the changes in the ecosystem. We give results of the first comprehensive inventory of the littoral cichlid fauna in southern Lake Victoria and discuss its conservation status. We also report on new developments in the sub-littoral fauna after 1990. More than 50 littoral and 15 sub-littoral stations were sampled between the years 1991 to 1995. Of the littoral stations, 34 were sampled for the first time. One hundred sixty three species of haplochromines were collected. Of these, 102 species were previously unknown. About two thirds of them live in rocky areas that were sampled for the first time. Littoral rocky habitats harbored the highest diversity. Since 1990, however, 13 more species disappeared from established sampling stations in littoral habitats. Fishing practices, spreading of exotic fishes, water hyacinth, and eutrophication are considered important threats to the littoral fauna. Also in the upper sub-littoral the number of species declined further. On deeper sub-littoral mud bottoms individual and species numbers increased again, although they are nowhere close to those found before the Nile perch (Lates niloticus) upsurge. This fauna differs from the well studied pre-Nile perch fauna. At well-established sampling stations, the sub-littoral zone is dominated by previously unknown species, and some known species have performed dramatic habitat shifts.