Morphological Constraints of Shoot Demography of a Clonal Plant: Extra- and Intravaginal Tillers of Festuca rubra

Abstract Festuca rubra forms tillers in two different ways: extravaginally and intravaginally. Demography of these two tiller types was observed in seventeen selected tussocks of Festuca rubra s.s. over four growing seasons. Extravaginal tillers were bigger at birth and on the average produced twice as many daughter tillers per tiller. In general, the natality and mortality of extravaginal tillers were less regular than that of intravaginal tillers. Overall tillering rate per tiller was correlated with the density of the surrounding vegetation; mortality, natality and tiller life span were not. High density of the surrounding vegetation did not result in increased formation of extravaginal tillers. The proportion of the extravaginal tillers was not correlated with the density of the F. rubra tussocks. There is no evidence for foraging by extravaginal tillers, but they do act as founders of small clusters of tillers.     

The identity of the type-species of Gonatocerus Nees (Hymenoptera: Mymaridae)

The validity of Gonatocerus Nees is discussed, and the identity of the type-species, G.longicornis, is established. Generic and specific synonymy is listed, and the neotype female of G.longicornis is redescribed.     

Rotoitidae, a curious new family of Chalcidoidea (Hymenoptera) from New Zealand

Abstract. A new chalcidoid family, Rotoitidae fam.n., is described from New Zealand. The probable systematic affinities of Rotoitidae are discussed and the type genus and a single included species, Rotoita basalis gen. et sp.n., are described and illustrated.     

Asymmetry in an Ordovician conulariid cnidarian

Sendino, C., Zágor?ek, K. & Taylor, P.D. 2012: Asymmetry in an Ordovician conulariid cnidarian. Lethaia, Vol. 45, pp. 423–431. Conulariids are fossils of the presumed polyps of an extinct scyphozoan cnidarian group. Their cone‐shaped skeletons normally show perfect tetraradial symmetry. However, in the Ordovician species Metaconularia anomala ( Barrande 1867 ) from Drabov (Czech Republic), tetraradial symmetry is compromised in three ways: (1) the skeleton often shows torsion; (2) the four sides may vary in width at the same level within one individual; and (3) one side may be deleted to give a triradial skeleton. Almost 2000 specimens were studied in museum collections. About 56% of analysed specimens are twisted in an anticlockwise direction (sinistral) when viewed from the apex towards the aperture, 28% show no torsion, 1% exhibit clockwise torsion (dextral) and the remaining 15% cannot be classified. Maximum measured torsion rate was 1.5°/mm. A significant negative correlation between torsion rate and length suggests that more highly torted individuals may have survived less well. Almost 5% of individuals show loss of one side for at least part of their lengths. Although many individuals have four sides of equal width, in a significant proportion the sides are of unequal width, up to a maximum/minimum side width ratio of 2 (i.e. widest face twice the width of the narrowest). In the absence of a satisfactory taphonomic model to explain the asymmetries, they are regarded as mirroring asymmetries in the living conulariids, with the strong preference for sinistral torsion interpreted as an example of a fixed asymmetry that was genetically controlled and heritable. It is speculated that the signalling protein Nodal as well as Hox‐like genes were involved in controlling the asymmetries described in M. anomala.     

Feasibility and Safety of Cervical Biopsy Sampling for Mucosal Immune Studies in Female Sex Workers from Nairobi,Kenya

Background

There is an urgent need to improve our understanding of the mucosal immuno-pathogenesis of HIV acquisition in the female genital tract, particularly in high-risk women such as female sex workers (FSWs). Cervical biopsy samples offer technical advantages over cytobrush sampling, but there are concerns that this might increase HIV acquisition, particularly if healing is slow and/or women do not abstain from sex during healing.

Methodology/Principal Findings

Cervical biopsy samples and cervico-vaginal swabs for co-infection diagnostics, prostate specific antigen (PSA) and immune studies were collected from 59 women, including HIV seropositive and HIV-exposed seronegative (HESN) FSWs as well as lower risk women from Nairobi, Kenya. A clinical-demographic questionnaire was administered and women were instructed to avoid sexual intercourse, douching and the insertion of tampons for 14 days. All participants underwent a repeat exam to assess healing within the 14 days, and had HIV diagnostics at six months. Cervical sampling was well tolerated, and 82% of participants had healed macroscopically by 5 days. Both self-report and PSA screening suggested high levels of compliance with pre- and post-procedure abstinence. Delayed healing was associated with vulvovaginal candidiasis (VVC) and HESN status. At six-month follow up all low-risk and HESN participants remained HIV seronegative.

Conclusion

Cervical biopsy sampling is a safe and well-tolerated method to obtain cervical biopsies in this context, particularly if participants with VVC are excluded. As healing could be delayed up to 11 days, it is important to support (both financially and with rigorous counseling) a period of post-procedure abstinence to minimize HIV risk.     

Absence of BoLA class I antigens on bovine spermatozoa

Summary. Forty AI bulls were tested for BoLA class I antigens by means of eight specific polyclonal reagents. By means of immobilization and sperm penetration tests these antigens were not detected on sperm cells. Isoimmunization studies with the use of sperm as antigenic stimuli and insemination of frozen spermatozoa diluted in specific reagents did not prove the presence of BoLA class I antigens on bovine spermatozoa. The cytotoxic tests used in this investigation were not reliable.     

AGE DEPENDENCE OF THE NUMBER OF THE STEM CELLS IN HAEMOPOIETIC TISSUES OF RATS

The number and concentration of haemopoietic stem cells in the femoral bone marrow and spleen of Wistar rats of different ages were investigated. Stem cells were assayed by the spleen colony technique in irradiated rat recipients. The ability of the recipient spleen to harvest transplanted tissue as a macroscopic colony was found to be dependent on the recipient's age. Changes with senescence were observed also in the concentration and the size of the stem cell compartment both in the marrow and spleen. No differences were demonstrated in the seeding of transplanted colony-forming units into the spleen of recipients of 1 and 4 months of age. A rats-mice strain difference in the effect of senescence on the haemopoietic stem cells is discussed.