Discocilia—A new type of kinocilia in the larvae of Lanice conchilega (Polychaeta,Terebellomorpha)

A modified type of kinocilia has been found in the Aulophora-Iarva of the sedentarian polychaete Lanice conchilega. For this newly described cilium type the term "discocilium" is proposed. The only structural difference from usual locomotory cilia is the tip, which possesses a discoidal head. The head is formed from the terminal part of the cilium shaft, which is bent to give rise to a loop-like ring covered by the ciliary membrane. Three types of discocilia can be distinguished: a) discocilia having swollen, bulblike heads with a central straight axoneme; b) discocilia having heads with a curved lateral axoneme and c) discocilia in which the axoneme forms a loop. The internal structure shows the usual 9 + 2 arrangement of the filaments. The head shows no sign of secretion; it appears structureless in electron microscopical examination. There are two kinds of discocilia arrangements: 1) isolated bunches of cilia especially at the tentacles and in the frontal region, and 2) segmental dorsal rows of cilia. The possible formation of discocilia is described.     

How localized are the distributions of Australian scarabs (Coleoptera,Scarabaeoidea)?

The degree of localization in the distribution of Australian scarabaeine (320 spp.), aphodiine (160 spp.), geotrupid (166 spp.) and dynastine (182 spp.) scarabs is analysed. Localization differs among these groups, appearing to increase marginally from the Dynastinae, to the Aphodiinae, to the Scarabaeinae, to the Geotrupidae, but with significant differences within groups, e.g. the scarabaeine tribes Onthophagini and Scarabaeini. However, the Australian fauna lacks the high proportion of widespread species characteristic of the West Palaearctic Scarabaeinae, Aphodiinae and Geotrupidae. This difference reflects the different ecological histories of the two regions.     

When and how did the Mikrotia fauna reach Gargano (Apulia,Italy)?

The time and mode of colonization of Gargano have been a subject of debate. Taking into account the temporal distribution of the ancestors of the Mikrotia fauna, a Late Tortonian age represents the best fit for the time of migration. How these animals reached the island is even harder to decide. In the past some scholars embraced rafting as an important mechanism enabling small mammals to reach the islands, whereas others rejected this hypothesis, considering it an improbable mode of colonization. The recent record of oceanic rafts indicates that rafting is indeed a very plausible method for small-sized animals to reach islands, and the most probable method for the colonization of Gargano. A polyphasic model, as proposed by Masini and colleagues, is rejected in the case of Gargano, as it is based on a misinterpretation of the adaptive radiations within the Mikrotia fauna.     

What are the maximum size and live body coloration of opah (Teleostei: Lampridae: Lampris species)?

Validity of the largest size accounts is not well documented and most published accounts of body coloration describe dead specimens lacking scales instead of the color of freshly caught opah. Maximum length is at least 163?cm fork length and maximum weight about 89?kg. The body color of fresh specimens is vermilion with white spots.     

Models of human genetic disease: how biased are the standard formulae?

Standard theory provides a simple prediction for the frequency of a recessive lethal allele conferring heterozygous protection against an infectious disease (the best-known example being sickle cell protection against malaria). This relationship allows historic disease mortality rates to be estimated. There are, however, hidden biases in this approach. Reproductively active human females in archaic societies normally produce children at intervals of around 4 years. If death of the fetus or young infant (less than around 3 years of age) occurs, then the mother re-enters oestrus and produces another child. This 'reproductive compensation' reduces selection against the agent causing early mortality (the recessive allele or infective agent) and biases our estimates of historic mortality rates. The magnitude of these biases is investigated. Re-conception also constitutes a demographic selective pressure acting alongside natural selection: lethal genetic diseases (or tightly linked loci) will be selected to become ever more virulent, killing at ever decreasing ages, to allow the mother to re-enter oestrus and re-conceive a (hopefully unaffected) sibling; this effect also invalidates statistical tests using the number of alleles to distinguish overdominance from drift as explanations for high allele frequency. The same bias affects calculations of mutation/selection balance: for any given mutation rate, syndromes which kill early in life will reach much higher frequencies than those killing at later ages. An intriguing consequence is that lethal recessive disorders in humans will increase in frequency by up to 45% as a consequence of the recent demographic transition to planned family size.     

Origin of the parasites of an invading species,the Australian cane toad (Bufo marinus): are the lungworms Australian or American?

Phylogeographical analyses that identify the geographical origin of parasites in invading species can clarify the parasites' potential for biological control of the invader and the risks posed by the parasite to native species. Our data on nuclear and mitochondrial genetic sequences show that the nematode lungworms (Rhabdias spp.) in invasive Australian populations of cane toads (Bufo marinus) are Rhabdias pseudosphaerocephala, a South American species. We did not find this lungworm species in any Australian frogs sympatric with cane toads, suggesting that the parasite does not attack Australian frogs and hence may offer potential as a biocontrol agent of the toad.     

Social Play or the Development of Social Behavior in Ferrets (Mustela putorius)?

Ferrets are the domesticated form of the European polecat. Changesin ferret kit, face to face orientation (en face) were describedfor littermate dyads at 46, 62, and 94 days after birth. Enface characteristics were discussed in terms of their appropriatenessfor reported burrow attachment and subsequent dispersal of polecatkits to illustrate both the transactional and the developmentalnature of our approach and to emphasize the neglected developmentalproblem of knowing the organization of kit behavior in its ecologicalsetting. This emphasis brings into question the appropriatenessof play criteria, reduces the heuristic value of play for thoseinterested in development, and suggests the importance of multipleendpoints for developmental investigations. Play also limitsdevelopmental investigations because of the nature of ethologicalbehavioral categories: Their adult, motivational, and evolutionaryemphases direct attention to "functional" rather than "analytic"questions. Although these questions are complementary, theyare not equally appropriate for problems of evolution and developmentbecause the former direct our attention of behavior of youngorganisms while the latter direct our attention to mechanismsof the developmental process. Our evaluation of play appliesequally well to other functional categories of behavior, suchas sexual and aggressive behavior.     

Molting in the Djungarian hamster (Phodopus sungorus Pallas): seasonal or continuous process?

After transfer into a short daylight regimen, the brownish summer pelage of the Djungarian hamster (Phodopus sungorus) changes into the whitish winter phenotype. Although changes in serum prolactin levels are identified as the initiating hormonal signal, morphological data about molting in that species are sparse. The aim of this study was to characterize in detail the summer and winter pelage of the Djungarian hamster and to analyze the alterations in the skin and pelage induced by photoperiodic changes. The main difference between summer and winter hair types is the pattern of pigmentation. In contrast to other mammalian species showing seasonal changes, the winter coat of the Djungarian hamster is not characterized by an increase in hair density. Molting patches were observed at all times, even in the winter coat, showing that the light regimen does not control the process of molting itself but the pattern of pigmentation and eventually the loss of hair during the single molting wave.     

Vascularizing the tissue surrounding a model biosensor: how localized is the effect of a subcutaneous infusion of vascular endothelial growth factor (VEGF)?

Implantable continuous biosensors would improve disease management but long term function of such devices have been limited by a hypovascular foreign body capsule that inhibits influx of analytes. To assess whether capsule vascularity could be increased, we studied the histologic effects of a 28-day continuous infusion of vascular endothelial growth factor (VEGF) (0.45 microg/day) vs. saline from the surface of a model disk biosensor that was implanted subcutaneously in rats. At day 40, tissue was obtained at varying distances from the infusion port and capsular microvessels were counted using two histologic techniques. VEGF treatment led to a marked increase in capillary density. In tissue located 1 mm away from the infusion site, capillary density in VEGF-treated animals was 200-300% higher than in saline controls. Tissue located 13 mm away, but not 25 mm away, also demonstrated neovascularization. Serum obtained from a distant vein during the infusion did not show an elevated concentration of VEGF. These data demonstrate that a subcutaneous infusion of VEGF creates localized neovascularization of the foreign body capsule and suggest that systemic effects of VEGF are avoidable. Vascularization of a foreign body capsule surrounding a subcutaneous biosensor might well extend its useful life.