Species dispersion profiles of anthropogenic grasslands in the Italian Eastern Pre-Alps

A method is proposed to analyse the dispersion profiles of species in classes of environmental variables, based on the decomposition of the expected frequencies in contingency tables with many interacting species. The method has been applied to data of dominant or very frequent graminoid species in grasslands of the Natisone Valley (Friuli, Italy). It allowed to make predictions by removing the random component of variation.Nomenclature follows: P. Zangheri (1976). Flora Italica, CEDAM, Padua.The authors were recipients of an Italian CNR grant (E. Feoli) and a Canadian NSERC grant (L. Orlóci) during tenure of this project. The results are in partial fulfillment of a commitment to the Centro Regionale per la Sperimentazione Agraria per il Friuli-Venezia Giulia.     

Muscle Tissue Damage Induced by the Venom of Bothrops asper: Identification of Early and Late Pathological Events through Proteomic Analysis

The time-course of the pathological effects induced by the venom of the snake Bothrops asper in muscle tissue was investigated by a combination of histology, proteomic analysis of exudates collected in the vicinity of damaged muscle, and immunodetection of extracellular matrix proteins in exudates. Proteomic assay of exudates has become an excellent new methodological tool to detect key biomarkers of tissue alterations for a more integrative perspective of snake venom-induced pathology. The time-course analysis of the intracellular proteins showed an early presence of cytosolic and mitochondrial proteins in exudates, while cytoskeletal proteins increased later on. This underscores the rapid cytotoxic effect of venom, especially in muscle fibers, due to the action of myotoxic phospholipases A₂, followed by the action of proteinases in the cytoskeleton of damaged muscle fibers. Similarly, the early presence of basement membrane (BM) and other extracellular matrix (ECM) proteins in exudates reflects the rapid microvascular damage and hemorrhage induced by snake venom metalloproteinases. The presence of fragments of type IV collagen and perlecan one hour after envenoming suggests that hydrolysis of these mechanically/structurally-relevant BM components plays a key role in the genesis of hemorrhage. On the other hand, the increment of some ECM proteins in the exudate at later time intervals is likely a consequence of the action of endogenous matrix metalloproteinases (MMPs) or of de novo synthesis of ECM proteins during tissue remodeling as part of the inflammatory reaction. Our results offer relevant insights for a more integrative and systematic understanding of the time-course dynamics of muscle tissue damage induced by B. asper venom and possibly other viperid venoms.     

Un indice che stima il peso dei caratteri per classificazioni monotetiche

Abstract

An « index weighing » characters for monothetic classifications. — The Author, according to the classification principles of maximization, presents an index in order to value in what measure characters may be considered good for monothetic classifications. The index is given by the ratio between the average similarity within a set of entities exhibiting the character whose importance we want to ascertain and the average similarity that such entities have with those not exhibiting it.     

Sero-systematics ofCytisus sect.Trianthocytisus (Fabaceae)

The serological reaction of seed proteins provides evidence for a partly new systematic arrangement ofCytisus sect.Trianthocytisus and ofCytisus s.l. Proposed modifications agree with recent advances in morphological taxonomy. Sect.Trianthocytisus includes only two species,C. villosus andC. aeolicus. Its position is central within the genus, and this fact agrees with the proposed retypification ofCytisus (type species:C. villosus).C. emeriflorus, formerly included in the same section, constitutes the monospecific sect.Emeroides, which is intermediate towards the genusLembotropis. This is serologically isolated and includes onlyL. nigricans. It is confirmed thatC. sessilifolius should be removed from the genusCytisus as a monospecific genus:Cytisophyllum Lang which is closely allied toHesperolaburnum and toPodocytisus, the most primitive genera ofGenisteae.     

Does Ordinal Cover Estimation Offer Reliable Quality Data Structures in Vegetation Ecological Studies?

Using visual estimation of species cover in ordinal interval classes may reduce costs in vegetation studies. In phytosociology, species cover within plots is usually estimated according to the well-known Braun-Blanquet scale and ordinal data from this scale are usually treated using common exploratory analysis tools that are adequate for ratio-scale variables only. This paper addresses whether the visual estimation of ordinal cover data and the treatment of these data with multivariate procedures tailored for ratio-scale data would lead to a significant loss of information with respect to the use of more accurate methods of data collection and analysis. To answer these questions we used three data sets sampled by different authors in different sites of Tuscany (central Italy) in which the species cover is measured with the point quadrat method. For each data set we used a Mantel test to compare the dissimilarity matrices obtained from the original point-quadrat cover data with those obtained from the corresponding ordinal interval classes. The results suggest that the ordinal data are suitable to represent the plot-to-plot dissimilarity structure of all data sets in a reasonable way and that in using such data there is no need to apply dissimilarity coefficients specifically tailored for ordinal scales.     

A general strategy for the simultaneous classification of variables and objects in ecological data tables

A general iterative algorithm is proposed for the arrangement of data matrices by optimizing X², sum of squares or pooled entropy for blocks determined by clusters of variables and objects. The method includes k-means clustering and constrained block clustering as special cases. Possibilities for evaluating the resulting matrix include calculation of relative contributions to measures of block sharpness, comparison of partitions and construction of consensus tables. A new measure for comparing rearranged data matrices is suggested. The distributional properties of final results produced under different starting conditions are examined. The performance of the algorithm is tested on binary vegetation data from the Italian Alps.     

Fuzzy set ordination and classification of Serengeti short grasslands,Tanzania

Abstract. Species abundance data from 32 representative stands are used to evaluate the vegetation in the heavily grazed Serengeti short grasslands. The abundant species are: Kyllinga nervosa, Sporobolus ioclados, S. kentro-phyllus and Eustachys paspaloides, all occurring in elevated areas, and Hypoestes forskalei, which is found in the drainage areas. Numerical classification and fuzzy set ordination revealed four main grassland communities associated with a topographic gradient. The communities are considered distinct since their niches, as computed in the community and environmental fuzzy system space are not overlapping. Leaching, erosion and animal disturbance effects correlated with the topographic gradient are found to determine species composition and overall community structure in the grasslands.     

Trypanosoma cruzi: immunosuppressed response to different antigens in the infected mouse.

Trypanosoma cruzi: Immunosuppressed response to different antigens in the infected mouse. Experimental Parasitology45, 190–199. Trypanosoma cruzi infection in mice results in functional changes in the normal immunological responses to heterologous antigens. An immunosuppression of the 19 and 7S antibody response is observed in infected animals against both a particulate antigen and against soluble antigens. Furthermore, the immune response to the soluble T-independent antigens, DNP-Ficoll and LPS, was also similarly impaired when antigen was administered to trypanosome-infected animals. The suppression of the immune response to these antigens does not seem to involve an alteration in the macrophage, as evidenced by a normal uptake and handling of soluble ¹³¹I-labeled HSA and by a normal immune response when antigen-exposed peritoneal macrophages from trypanosome-infected mice were transferred to normal mice. These data support the concept that T. cruzi induces an immunosuppression to both T-dependent and T-independent antigens and that the depression observed is not due to an alteration in macrophage function.     

Correlations between capillary microscopy and electrocardiographic results in the diabetic

Ninety-nine diabetics were simultaneously given a capillaroscopic examination of periungual walls and an electrocardiogram evaluated according to the Minnesota Code. From these tests the following data were recorded: a. the number of knobs revealed by capillaroscopy is inferior, in a statistically significant manner, in groups having "major abnormalities"; b. capillaroscopic abnormalities did not seem to be definitely correlated to age, but rather to the length of time diabetes mellitus was present; in particular, these abnormalities were quite evident in subjects diagnosed as diabetics for the first time. This procedure is therefore extremely useful for the early diagnosis of diabetic microangiopathy; c. electrocardiographic abnormalities are correlated to patient's age, whereas are not related to the period of the illness. Although the small sampling obliges us to maintain certain reservations, such abnormalities were more frequent in subjects taking antidiabetic drugs orally.