The Climate-Species-Matrix to select tree species for urban habitats considering climate change

Two hundred and fifty urban woody species are used in Central European parks and gardens. Based on reliable publications we attempt, for the first time, to extensively classify and assess them with regards to their usability after predicted climate changes. A new Climate-Species-Matrix has been developed for this purpose. In a two-dimensional assessment, four degrees of drought resistance and winter robustness are the decisive criteria. The woody species (divided into trees of more than 10 m in potential height and trees/shrubs of up to 10 m in height) were placed into 16 categories by decreasing tolerance, ranging from 1-1 (very suitable) to 4-4 (very limited usability). For many of these species, as well as many others that are not mentioned in this study, not all questions could be answered. Nonetheless, this categorization provides a sound basis for decisions in planning the use of woody species in cities. This planning process must also include additional criteria, dependent on individual requirements such as, soil parameters, shade resistance, aesthetics, etc. This paper is therefore meant to be a basis for discussion and supplementation for further research.     

Analysis of semen quality from each testis/duct system of a turkey with a duplicated cloaca and vent

A case is described wherein a turkey male (tom) possessed two vent areas with duplicated cloacae served by one large intestine. Both cloacae were functional in that feces were excreted and semen could be collected from each. The left vas deferens and ureter emptied into the left cloaca, and the right vas deferens and ureter emptied into the right cloaca. This allowed semen from each testis/duct to be collected separately from the corresponding cloaca. Thus, a unique opportunity was presented to collect semen separately from the left and right testis/duct system for semen analysis and fertility determination. Sperm concentration and percentage of dead sperm were not significantly different when semen from left vs. right reproductive tract were compared. The concentrations of spermiophages in semen from both reproductive tracts fell into the range reported for normal semen (0-8 x 10(5)/ml); however, semen from the right side had consistently higher spermiophage concentrations than that from the left side. On the basis of observations from one male made possible by an anatomic anomaly, it appears that the fecundities of the left and right testis/duct systems of the turkey male do not significantly differ and that recruitment of spermiophages into one tract (because of immunologic challenge, etc.) does not necessarily mean that the opposite testis/ducts will respond similarly.     

Ras p21 as a potential mediator of insulin action in Xenopus oocytes

The oncogene protein product (p21) of the ras gene has been implicated in mediating the effects of a variety of growth factors and hormones. Microinjection of monoclonal antibody 6B7, which is directed against a synthetic peptide corresponding to a highly conserved region of p21 (amino acids 29 to 44) required for p21 function, specifically inhibited Xenopus oocyte maturation induced by incubation with insulin. The inhibition was dose-dependent and specific since (i) the same antibody had no effect on progesterone-induced maturation, (ii) immunoprecipitation and Western blotting indicated that the antibody recognized a single protein of molecular weight 21,000 in oocyte extracts, and (iii) inhibition was not observed with identical concentrations of normal immunoglobulin. Thus, p21 appears to be involved in mediating insulin-induced maturation of Xenopus oocytes. Furthermore, the mechanism may involve phosphorylation of p21, as p21 was found to be a substrate of the insulin receptor kinase.     

Single-shot channel activation accounts for duration of inhibitory postsynaptic potentials in a central neuron

In the goldfish Mauthner cell, inhibitory postsynaptic currents evoked by intracellular stimulation of presynaptic neurons decay exponentially, with a mean time constant of 6.65 milliseconds. Analysis of membrane conductance fluctuations induced by iontophoresis of glycine and gamma-aminobutyric acid indicates a mean inhibitory channel lifetime of 7.15 milliseconds. The results thus suggest that the relaxation kinetics of activated inhibitory channels are rate-limiting during decay of the inhibitory postsynaptic current.     

Structure of biological membranes

The combined x-ray diffraction and electron microscopic examination of myelin has provided reasonable, but not conclusive, support for its structure as a basically bimolecular leaflet of phospholipid that is partially interspersed with protein. But there is very little basis for extending this concept to biological membranes in general. There is no adequate experimental support for the specific orientation of phospholipids as proposed in the unit membrane theory or for the proposed polar nature of protein-lipid bonds, even in myelin. Membranes differ widely in chemical composition, metabolism, function, enzymatic composition, and even in their electron microscopic image. The only similarity is their general resemblance in electron micrographs, but, until more is known about the chemistry of electron microscopy, this evidence cannot be interpreted with confidence. One positive conclusion to which I have come is that much more chemical evidence must, and can, be obtained. Techniques for the isolation of membranes are improving and protein and lipid chemistry are now highly refined arts. Quantitative analysis of many different membranes is possible and the data can be related in some instances, notably bacterial plasma membranes, to calculations of surface area. Chemical and physical changes induced in membranes of widely different lipid composition by the preparatory procedures of electron microscopy can be determined directly and correlated with the electron microscopic image. Model systems can be assembled whose compositions closely resemble those of biological membranes. Membranes can be disassociated into subunits whose properties can be studied. In particular, x-ray diffraction analysis and electron microscopy by negative staining of reaggregates of lipoproteins isolated from membranes would be very informative. Perhaps most important, the problem of membrane structure must be considered in relation to the problems of membrane function and membrane biosynthesis.     

Animal welfare relevance and the functional and morphological significance of the killing of laboratory animals

Euthanasia of experimental animals at the end of an experiment or when an experiment is terminated is relevant for two reasons: firstly, because of ethical reasons and of animal protection, secondly because of scientific evaluation of experimental results. Functional and morphologic alterations have up to now been inadequately observed and considered. Gradually varying different results depend on the different methods of euthanasia. Additionally single parameters of reactions in isolated organs vary depending on the method of euthanasia. These facts have not yet been respected in the discussion of so called alternate methods. The significance of functional and morphologic effects as seen in different methods of euthanasia is discussed with examples.