Fenbendazole and its effect on the immune system of the sheep

Ten parasite-free 6-month-old lambs were drenched on days 0 and 28 with fenbendazole and 1 day after each drench were injected with human erythrocytes and ovalbumin. Ten other lambs injected with the antigens were not drenched with anthelmintic and served as controls. Lymphocytes from the fenbendazole-drenched lambs collected 3 days after the first antigen injections and cultured in vitro in RPM1 1640 plus 5% foetal calf serum, and lymphocytes collected at 3 and 7 days and cultured in RPM1 plus 50% autologous serum, had decreased blastogenic activity compared with lymphocytes from control lambs. Similarly, decreased blastogenesis was observed with lymphocytes collected 7 days after the second antigen injections from drenched lambs and cultured in 50% autologous serum containing concanavalin A. In contrast, increased blastogenesis was seen with lymphocytes collected 14 days after the second antigen injections from the drenched lambs and cultured in 50% autologous serum containing phytohaemagglutinin. Similar antibody responses were seen for the drenched and control lambs in response to the injections of both antigens except that, after the second injection, there was a significant reduction in antibody response to human erythrocytes in the fenbendazole-treated lambs. Decreased serum complement levels were seen particularly 3 and 7 days after the second antigen injections in drenched lambs. These serum samples had increased conglutinin activity. At the end of the experiment, the fenbendazole-drenched lambs were significantly heavier than the control lambs. However, this did not appear to be related to any effects of fenbendazole on levels of growth promoting hormones.     

Changes in the spleen and liver of pregnant sows and full-term piglets after feeding diets naturally contaminated with deoxynivalenol and zearalenone

Wheat contaminated naturally with the Fusarium toxins deoxynivalenol (DON) and zearalenone (ZON) was fed to pregnant Landrace sows for 35days. On day 110, caesarean section was carried out, the offspring were killed immediately after birth, and their livers and spleens examined. At necropsy there were no macroscopic lesions observed in any organ of either sows or piglets. Histopathological evaluation of tissues from sows of the treated group revealed changes in liver and spleen tissues, whereas no significant changes were observed in these tissues in their piglets. Liver damage, as measured by prominent elevated transaminase activities, was not detected in the serum of the sows. In pregnant sows there were individual variations in sensitivity to the Fusarium toxins. In conclusion, it can be assumed that there are no adverse effects on the liver and spleen of full-term piglets when their mothers consumed diets containing up to 9570 and 358mug DON/ZON per kg diet.     

People and pines 1555<Emphasis Type="Bold">–</Emphasis>1910: integrating ecology,history and archaeology to assess long-term resource use in northern Fennoscandia

Context

Past human land use has received increasing attention as an important driver of ecosystem change also in seemingly natural landscapes. Quantification of historical land use is therefore critical for assessing the degree of human impact and requires integration of ecology, history and archaeology.

Objective

This study aims to assess and compare levels of resource use by different actors during 355 years across a large landscape of northern Sweden.

Method

Data on resource use derived from case studies were extrapolated using demographic data to estimate harvested resources at the landscape scale. Here, we examined the use of the key-specie Scots pine by native Sami peoples and farmers and through commercial logging, and reconstructed historical forest conditions in order to interpret harvest levels and sustainability.

Results

We show that (1) the pre-industrial use of Scots pine resources in Pite Lappmark was sustainable from a landscape perspective, and (2) that the early commercial logging, in contrast, was not sustainable. Large and old Scots pine trees were logged at a very high rate, reaching up to 300 % of the annual ingrowth.

Conclusion

We suggest that historical landscape studies should incorporate analysis at different spatial scales, as such an approach can mirror the overall use of resources. Only then can land use data be applied across larger spatial scales, function as reference values and be compared to those of other regions, time-periods and types of human impact.

     

Estimating Grazing Potentials in Sudan Using Daily Carbon Allocation in Dynamic Vegetation Model

Livestock production is important for local food security and as a source of income in sub-Saharan Africa. The human population of the region is expected to double by 2050, and at the same time climate change is predicted to negatively affect grazing resources vital to livestock. Therefore, it is essential to model the potential grazing output of sub-Saharan Africa in both present and future climatic conditions. Standard tools to simulate plant productivity are dynamic vegetation models (DVMs). However, as they typically allocate carbon to plant growth at an annual time step, they have a limited capability to simulate grazing. Here, we present a novel implementation of daily carbon allocation for grasses into the DVM Lund-Potsdam-Jena General Ecosystem Simulator (LPJ-GUESS) and apply this to study the grazing potential for the Kordofan region in Sudan. The results show a latitudinal split in grazing resources, where the northern parts of Kordofan are unexploited and southern parts are overused. Overall, we found that the modeled grazing potential of Kordofan is 16% higher than the livestock usage reported in the Food and Agricultural Organization of the United Nations, indicating a mitigation potential in the form of a spatial relocation of the herds.     

A pericyte origin of spinal cord scar tissue

There is limited regeneration of lost tissue after central nervous system injury, and the lesion is sealed with a scar. The role of the scar, which often is referred to as the glial scar because of its abundance of astrocytes, is complex and has been discussed for more than a century. Here we show that a specific pericyte subtype gives rise to scar-forming stromal cells, which outnumber astrocytes, in the injured spinal cord. Blocking the generation of progeny by this pericyte subtype results in failure to seal the injured tissue. The formation of connective tissue is common to many injuries and pathologies, and here we demonstrate a cellular origin of fibrosis.