Early infections by myxoma virus of young rabbits (Oryctolagus cuniculus) protected by maternal antibodies activate their immune system and enhance herd immunity in wild populations

The role of maternal antibodies is to protect newborns against acute early infection by pathogens. This can be achieved either by preventing any infection or by allowing attenuated infections associated with activation of the immune system, the two strategies being based on different cost/benefit ratios. We carried out an epidemiological survey of myxomatosis, which is a highly lethal infectious disease, in two distant wild populations of rabbits to describe the epidemiological pattern of the disease. Detection of specific IgM and IgG enabled us to describe the pattern of immunity. We show that maternal immunity attenuates early infection of juveniles and enables activation of their immune system. This mechanism associated with steady circulation of the myxoma virus in both populations, which induces frequent reinfections of immune rabbits, leads to the maintenance of high immunity levels within populations. Thus, myxomatosis has a low impact, with most infections being asymptomatic. This work shows that infection of young rabbits protected by maternal antibodies induces attenuated disease and activates their immune system. This may play a major role in reducing the impact of a highly lethal disease when ecological conditions enable permanent circulation of the pathogen.     

Relationship among GeneSTAR marbling marker, intramuscular fat deposition, and expected progeny differences in early weaned Simmental steers

Research has demonstrated that triiodothyronine and thyroxin are correlated with marbling (MARB) deposition in Wagyu cattle. Polymorphisms in the 5' region of the thyroglobulin gene have been associated with an improvement in overall fattening and could be used as a gene marker for MARB. The commercially available GeneSTAR MARB test measures the specific thyroglobulin gene polymorphism and identifies cattle as having 0, 1, or 2 copies of the allele; these are identified as 0-STAR, 1-STAR, or 2-STAR, respectfully. Early weaned Simmental steers (n = 192) of known genetics were individually fed over a repeated 4-yr trial period to determine the correlations between GeneSTAR MARB test [Genetic Solutions/Bovigen Pty. Ltd. (Australia) in conjunction with Frontier Beef Systems, LLC (Louisville, CO)] results and intramuscular fat (IMF) deposition. Yearling weight, MARB, percent retail cuts, and carcass weight EPD were calculated for each steer. Steers were weaned at 88.0 +/- 1.1 d, pen-fed a high-concentrate diet for 84.5 +/- 0.4 d before allotment, and subsequently individually fed a 90% concentrate diet composed primarily of cracked corn and corn silage for 249.7 +/- 0.7 d. Steers were slaughtered at 423.3 +/- 1.4 d. Deoxyribonucleic acid samples were used by Genetic Solutions/Bovigen (Australia) for GeneSTAR MARB analysis. Steers with allele types of 0-STAR (n = 47), 1-STAR (n = 95), and 2-STAR (n = 33) had no effect (P > 0.10) on MARB score, chemically determined IMF percentage, quality grade, or percent low Choice and better. There were no differences (P > 0.10) in performance or other carcass parameters among the allele types. GeneSTAR results were not associated with MARB (P > 0.10). Conversely, MARB EPD was correlated (P < 0.01) with MARB score (r = 0.44) and IMF percentage (r = 0.27). Thus, in this management system, MARB EPD is an accurate predictor of IMF deposition. These data suggest that the GeneSTAR MARB marker was not an efficacious predictor of IMF deposition in early weaned Simmental steers fed a high-energy diet.     

Understory Response to Repeated Thinning in Douglas-fir Forests of Western Oregon

This study investigated effects of a second-thinning entry on understory vegetation and tree regeneration development and understory vegetation composition. Study sites were located in the Coast Range and Cascade Range mountains of western Oregon and were dominated by Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) forests. Stands were initially thinned between 1975 and 1982 and parts of these same stands were thinned again approximately 20 yr later. Thinning stands a second time resulted in greater amounts of fern, graminoid, and open-site species, but the abundance of tree regeneration was not affected. Despite different site conditions, compositional patterns in the understory consistently shifted toward open-site early seral species following the second thinnings. These results suggest that the initial impacts of a second thinning are not simply predictable from studies in which only a single thinning was implemented. It is important to consider that vegetation trends were already influenced by the previous thinnings, and impacts of the second thinning are thus not as easily detectable. Within these limitations, repeated thinnings may be an effective management tool to maintain early seral species in older forests, while other aspects of understory vegetation and tree regeneration are less influenced in the short term.     

Food value of field beans for chickens and evaluation of various portions with special reference to the tannin-poor sort in broiler fattening food

The investigations were carried out with varieties rich in tannin (Erfordia, Fribo) and one poor in tannin (White Flowering). The protein of the variety poorer in tannin is slightly richer in methionine and is slightly better digested. The studies on the varieties Erfordia, Fribo and White Flowering in quotas of 7.5...45% as component in the fattening feed for broilers resulted in the same fattening performance as in the control group (maize-soybean-fishmeal ration) and had no influence on the chemical composition of the body and the weight of the pancreas. All rations were isonitrogenous and isocaloric. The soybean oilmeal in the ration was replaced gradually resp. completely by the field bean coarse meal in connection with methionine supplements. The variety poorer in tannin did not have nutrition-physiologic advantages in the the growth experiment with young broiler chickens.     

The foot and ankle of Australopithecus sediba

A well-preserved and articulated partial foot and ankle of Australopithecus sediba, including an associated complete adult distal tibia, talus, and calcaneus, have been discovered at the Malapa site, South Africa, and reported in direct association with the female paratype Malapa Hominin 2. These fossils reveal a mosaic of primitive and derived features that are distinct from those seen in other hominins. The ankle (talocrural) joint is mostly humanlike in form and inferred function, and there is some evidence for a humanlike arch and Achilles tendon. However, Au. sediba is apelike in possessing a more gracile calcaneal body and a more robust medial malleolus than expected. These observations suggest, if present models of foot function are correct, that Au. sediba may have practiced a unique form of bipedalism and some degree of arboreality. Given the combination of features in the Au. sediba foot, as well as comparisons between Au. sediba and older hominins, homoplasy is implied in the acquisition of bipedal adaptations in the hominin foot.