Hunter feedback of individually marked wild boar <Emphasis Type="Italic">Sus scrofa</Emphasis> L.: dispersal and efficiency of hunting in northeastern Germany

Increasing wild boar (Sus scrofa L.) population densities all over Europe cause severe economic problems. For understanding mechanisms of epidemics, the knowledge of dispersal is required. Thus, we investigated dispersal rates and distances with regard to sex and age of wild boar in southwestern Mecklenburg-Western Pomerania. From 152 marked wild boar, 105 have been registered as dead, of which, 51% were males and 49% females. Forty-five percent were shot as piglets, 41% as yearlings, and 14% as adults. The distance between capture site and site of death ranged between 184 m and 41.5 km. Piglets were shot closer to their capture site (mean distance 1 km) than older animals (mean 4 km), although this difference was only significant for males. In general, males tended to disperse further before being shot (3.8 km) than females (1.6 km). Only 3.8% of all animals were shot at distances larger than 10 km. As most animals (84.6%) were shot inside their natal home range, only a small proportion (15.4%) did actually disperse (shot outside mothers home range), which is 32% of all animals surviving to the age of yearlings. Of those dispersed animals, 25% were females. The low dispersal rate is biased by female philopatry and allows actual dispersal only at very high population densities or in sparsely populated regions. In consideration for the low natural mortality proved by radio-tagged animals, the harvest rate is lower than the net reproduction. We did not detect any sex-biased hunting. The dominating hunting method was single hunt at bait, although drive hunts are highly effective. However, hunting rates on piglets and females were too low for regulating the population.     

Mapping and Genetic Characterization of Loci Controlling the Restoration of Male Fertility in Ogura CMS Radish

Three Raphanus populations (BC1, F2 and R8) each segregating for the restoration of Ogura CMS were used tomap restorer loci. The three restorer loci, Rf1, Rf2 and Rf3, each exhibited dominant restoring alleles and wereeach mutually epistatic. Rf1 was mapped to the upper region of Rs1 using data from each population. Rf2 wasmapped to the middle of Rs2 using both the F2 and R8 populations. Rf3 was mapped to the upper region of Rs7using the R8 population. The marker analysis and linkage mapping of the BC1 and F2 populations were describedpreviously (Bett and Lydiate, 2003). Scoring at 114 marker loci in R8 population allowed a new map ofthe Raphanus genome to be integrated with the consensus map. The complex genetic control of the restoration ofOgura CMS in Raphanus is compared with the more simple genetic control of this trait previously described inB. napus. Markers linked to each of the three restorer loci will allow the routine generation and verification ofdefined restorer and maintainer lines for various combinations of defined restorer loci. Although the restorationof Ogura CMS in Raphanus probably involves additional loci, the identification of three loci and diagnosticmarkers for each provides a solid foundation for the development of a holistic model for the genetic control ofthis trait through mapping in additional populations.     

Resistant invaders can convey benefits to native species

Introduced species are recognized as a major threat to native species. One factor that facilitates their spread is that they are often resistant to natural enemies of their native competitor. Negative effects of the invaders are often documented, but invaders may also convey benefits to the natives if they interfere with the native host-parasite interactions. If invaders act as resistant targets for the native parasites, they may reduce the density of the infectious transmission stages ('dilution effect') and decrease the risk of infection for the natives. We tested this hypothesis by exposing coexisting native and introduced freshwater snails to infectious stages of a native parasite. The native hosts showed a significantly reduced infection rate when exposed together with the resistant invader. A significant amount of the parasite transmission stages was wasted on the resistant invader leading to lower risk of infection for the natives. Our results show that invaders may convey benefits to the native competitors by perturbing the native host-parasite interaction and support the idea that the 'dilution effect' could be important for invaded communities.     

Relationship between thyroid size and urinary concentration of iodine in the population of Bialystok]

The survey carried out in May 1991 in the city of Bia?ystok comprised 308 children of age between 8 and 14 years and 116 young adults. In each of the studied subjects the size of the thyroid was measured by ultrasonography and iodine concentration determined in a randomly voided sample of urine. Body weight and height of the subjects have also been measured. In about 50% of the subjects studied (58.4% of children, 38.5% of men and 58.4% of women) the presence of goiter accompanied by a low urinary iodine concentration (median--2.0 micrograms/ml) was found. A significant negative correlation between the thyroid size and urinary iodine concentration, and lack of relation between the former and TSH concentration, have been found. No relation was observed between the presence of goiter and the inadequate physical development in the children studied. Insignificantly elevated TSH levels without accompanying clinical symptoms of hypothyreosis were observed in 8.7% of children, 3.8% of women and 5.1% of men studied. Higher prevalence of goiter found as compared to the results previously obtained in the same area can be related on the one to the use of more precise methods and on the other to real worsening of the situation due to discontinuation of obligatory iodine prophylaxis in the country more than 10 years ago.     

Breast carcinoma and malignant melanoma metastasis within a single axillary lymph node

A 58 year old lady presented with a right breast cancer and a prior history of malignant melanoma excised from the right chest wall eight years previously. An abnormal axillary lymph node resected contained features of both metastatic breast carcinoma and malignant melanoma. Following oncologic breast cancer management, the patient is well with no evidence of recurrence at three years.     

Natural range expansion and human-assisted introduction leave different genetic signatures in a hermaphroditic freshwater snail

Colonization events like range expansion or biological invasions can be associated with population bottlenecks. Small population size may lead to loss of genetic diversity due to random genetic drift, to loss of heterozygosity due to increased inbreeding and should leave a signature on the genetic polymorphism and genetic structure of populations. The mating system might additionally influence the outcome of such a process. Here, we compare invasive and native populations of the hermaphroditic freshwater snail Lymnaea stagnalis. In the native range we included populations that were ice-free during the last glaciation period and populations that were glaciated and are located at the edge of the species’ native distribution range. The microsatellite data show substantial loss of genetic variation in the introduced range and no signs of high propagule pressure or admixture. The expressed polymorphism was so low that mating system analysis was not possible. In the native region, all populations display strong levels of differentiation (global F _ST: 0.341) independent of colonization history and exhibit no significant pattern of inbreeding. However, the populations in more recently colonized habitats show diminished genetic diversity. Overall, these results illustrate how dramatic the reduction in genetic diversity can be for hermaphroditic animals and that gene flow in the native range can be surprisingly low despite short distances.     

Membrane lymphotoxin-α2β is a novel tumor necrosis factor (TNF) receptor 2 (TNFR2) agonist

In the early 1990s, it has been described that LTα and LTβ form LTα₂β and LTαβ₂ heterotrimers, which bind to TNFR1 and LTβR, respectively. Afterwards, the LTαβ₂–LTβR system has been intensively studied while the LTα₂β–TNFR1 interaction has been ignored to date, presumably due to the fact that at the time of identification of the LTα₂β–TNFR1 interaction one knew already two ligands for TNFR1, namely TNF and LTα. Here, we show that LTα₂β interacts not only with TNFR1 but also with TNFR2. We furthermore demonstrate that membrane-bound LTα₂β (memLTα₂β), despite its asymmetric structure, stimulates TNFR1 and TNFR2 signaling. Not surprising in view of its ability to interact with TNFR2, LTα₂β is inhibited by Etanercept, which is approved for the treatment of rheumatoid arthritis and also inhibits TNF and LTα.Subject terms: Cytokines, Signal transduction