Pseudocatamachilis gen.n., a new genus of Machilidae (Insecta, Apterygota, Microcoryphia) from Spain

A new genus, Pseudocatamachilis gen.n. is established on the basis of a thorough study of many specimens male and female of Catamachilis torquata (Nav#aAs, 1905). All type material was lost during the Spanish civil war (1936-39). A neotype is designated and the species redescribed. Genus Pseudocatamachilis is related to Catamachilis Silvestri and Promesomachilis Silvestri, but distinguished from these genera by the type of ovipositor and the presence of two pairs of parameres, among other characteristics given in the text.     

Population structure and gene flow of the Atlantic walrus (Odobenus rosmarus rosmarus) in the eastern Atlantic Arctic based on mitochondrial DNA and microsatellite variation

The population structure of the Atlantic walrus, Odobenus rosmarus rosmarus , was studied using 11 polymorphic microsatellites and restriction fragment length polymorphism detected in the NADH-dehydrogenase ND1, ND2 and ND3/4 segments in mtDNA. A total of 105 walrus samples were analysed from northwest (NW) Greenland, east (E) Greenland, Svalbard and Franz Joseph Land. Two of the 10 haplotypes detected in the four samples were diagnostic for the NW Greenland sample, which implied that the group of walruses in this area is evolutionary distinct from walruses in the other three areas. One individual sampled in E Greenland exhibited a Pacific haplotype, which proved a connection between the Pacific walrus and walruses in eastern Greenland. The Franz Joseph Land, Svalbard and E Greenland samples shared the most common haplotype, indicating very little differentiation at the mtDNA level. Gene flow ( Nm ) estimates among the four areas indicated a very restricted exchange of female genes between NW Greenland and the more eastern Atlantic Arctic samples, and a closer relationship between the three samples composing the eastern Atlantic Arctic. The genetic variation at 11 polymorphic microsatellite loci grouped individuals into three populations, NW Greenland, E Greenland and a common Franz Joseph Land–Svalbard population, which were connected by moderate gene flow.     

Significance of the White Sea as a stopover for Bewick's Swans Cygnus columbianus bewickii in spring

We searched for a major stopover site of Bewick's Swans Cygnus columbianus bewickii in the White Sea following the suggestion that one should exist on the stretch between Estonia and the breeding grounds (1750 km). We discovered 733 Swans in Dvina Bay during a late aerial survey in spring 1993. Subsequently, ground-based research was carried out in May 1994, 1995 and 1996 in the Dry Sea, a tidal, shallow bay with fresh to brackish water just north of the Dvina Delta. The total number of passing Bewick's Swans was estimated at 10974 (1994), 9593 (1995) and 17 972 (1996) (32–60% of the flyway population). Estimated peak numbers staging were 1500–2000 (9 May 1994), 4937 (17 May 1995) and 4457 (24 May 1996) (> 5–16% of the flyway population). The Swans foraged almost exclusively on submerged water plants apart from some supplemental feeding on emerged food plants around high tide. Stoneworts Chara spp. were an important food in the late spring of 1996, because they grew in places where bog streams quickly melted the ice. At this latitude (65̀N) food alternatives to the submerged macrophytes are rare in spring, but we cannot rule out the possibility that the Swans forage on grass rhizomes on inundated pastures. One bird tracked by satellite staged 15 days in Dvina Bay, of which four days were spent in the Dry Sea, in accordance with other indications that the Dry Sea is part of a larger stopover site within Dvina Bay. Recent evidence shows that the Swans largely skip the White Sea during autumn migration. However, in spring the birds probably need this stopover to be able to carry reserves to the breeding grounds. At present, the preservation of the submerged vegetation in Dvina Bay seems to be crucial to the conservation of this Bewick's Swan population.     

IMPROVEMENT OF TRIANGLE TEST DATA BY USE OF INCENTIVES

The objectives of this study were to determine the distribution of the sensory panelists' ability to detect differences and to improve the triangle test by minimizing unnecessary guessing. The triangle test was modified to include the use of economic incentives through which panelists voluntarily revealed their ability to detect differences. Panelists were asked to estimate their ability to detect differences and the probability of identifying the odd sample in a triangle test. They were then organized into three ability groups according to their responses. Double triangle tests, followed by triangle tests with economic incentives, were used to evaluate a cereal product and a beverage. The ability to detect differences was modeled as a probability, and the distribution of panelists was estimated. The economic incentives test was more effective when used with the beverage in which differences were less difficult to detect. We found that the economic incentive test discouraged the panelists from guessing unnecessarily, thus increasing the motivation of the panelists to detect differences, and allowing researchers to determine the distribution of discrimination ability.     

Experimental infection of wild‐caught European rabbits (Oryctolagus cuniculus) with Sarcoptes scabiei from a naturally infected wild rabbit

Scabies was recently reported for the first time in the European wild rabbit, Oryctolagus cuniculus (Lagomorpha: Leporidae). We experimentally exposed 10 seronegative wild‐caught rabbits to skin from a mangy wild rabbit. Serological, physiological, parasitological and histopathological changes were recorded. Three rabbits developed antibodies at 2–5 weeks post‐infection (w.p.i.), two of which then developed lesions at 7 w.p.i. One of these had a small area of alopecia on the hind limb that healed naturally within 1 week; the other developed more extensive lesions restricted to the hind limbs (as typically observed in wild rabbits) that lasted until the rabbit died (12.5 w.p.i.). The third rabbit died of trauma 5 w.p.i. before developing any lesions. Antibodies in the healed rabbit disappeared from serum at 8 w.p.i., whereas antibody levels in the sick rabbit increased until its death. Disseminated intravascular coagulation and hepatic necrosis, probably arising from a concomitant infection with rabbit haemorrhagic disease virus, were the likely final cause of death in this rabbit. The mangy rabbit that served as a donor died of a multifocal fibrinosuppurative pneumonia that may have been secondary to the skin bacterial pyoderma.     

Comparison of Mitomycin C and X-irradiation as Blocking Agents in One-way Mixed Leucocyte Cultures

THE mixed leucocyte culture (MLC) test^1,2 has been widely used as a measure of histocompatibility in man and as a model for the recognition phase of the homograft response in vitro. Two methods have been proposed to achieve unidirectional stimulation in MLC: treatment of stimulating cells with either mitomycin C³ or X-irradiation³. The mitomycin C method has the advantage of not requiring expensive X-ray equipment and being immediately available in the laboratory; the X-ray method has the advantage of not requiring washing of the cells following treatment. Although much of the quantitative MLC work for histocompatibility testing in man has been done using mitomycin C, the general impression gained from the literature as well as the studies we report here would support the use of either method. A previous study⁴ suggested that irradiation is superior to mitomycin C treatment for a number of reasons, but we question those conclusions.