Search results for "Alpi"

DNA Content and Synthesis in Several Tissues and Variation of Moulting Hormone-Level in Gryllus bimaculatus DEG (Ensifera, Insecta)

1983

The mode of growth of several tissues in Gryllus bimaculatus was investigated during postembryonic development by cytophotometric methods. In contrast to the situation in holo- metabolous insects, the tissues growing by endomitosis reach only moderate levels of polyploidy. In this case the growth of tissues is achieved by mitotic divisions of small cells with subsequent polyploidization. The time courses of DNA synthesis were measured within the 3rd and, for comparison, the 8th larval instar by incorporation of labelled thymidine followed by autoradiography. Hemocytes, cells of the regeneration crypts of the midgut, gonads and nervous tissue showed a continuous incorporation rate; by contra…

Ultrastructure of embryonic envelopes and integument ofOncopeltus fasciatus dallas (Insecta, Heteroptera)

1978

The embryo ofOncopeltus fasciatus forms a typical secondary dorsal organ (SDO). It develops after katatrepsis from the contracting serosa, the cells of which decrease in diameter but increase considerably in height. After 66 h, the SDO represents a protrusion of the serosal epithelium above the head and is then reduced to a disc-shaped formation, which sinks into the yolk, where it disintegrates after 80 h. During its typical expression, between 66 and 78 h, the SDO shows a zonal arrangement of its cell organelles. The nucleus, which is located in the basal cell region, has a very irregular outline and includes several nucleoli and globular inclusion bodies. Rough and smooth ER are well dev…

Lignocellulosic fillers and graphene nanoplatelets as hybrid reinforcement for polylactic acid: Effect on mechanical properties and degradability

2020

Abstract This work investigates the effect of adding relatively low amounts of graphene nanoplatelets (GNP) to a biocomposite based on polylactic acid (PLA) and a lignocellulosic filler achieved by grinding Posidonia Oceanica leaves (Posidonia flour, PF). The ternary composites were prepared by melt extrusion and characterized from a morphological and mechanical point of view. Furthermore, hydrolytic degradation tests were performed under acidic, neutral and alkaline environment up to 900 h. Density measurements enabled to assess the degree of intraphase, i.e. the capability of polymer macromolecules to enter the voids of PF and a modified Halpin-Tsai model was presented and used to fit exp…

Structure-property relationship of PLA-Opuntia Ficus Indica biocomposites

2019

Abstract In this work, a lignocellulosic flour was achieved by grinding the cladodes of Opuntia Ficus Indica and then added to a poly-lactic acid (PLA) in order to prepare biocomposites by melt processing. The influence of filler content and size on the morphological, rheological, and mechanical properties of the green composites was assessed. Moreover, solvent-aided filler extraction enabled to evaluate the homogeneity of filler dispersion, as well as the effect of processing on the geometrical features of the fillers. The experimental data obtained by tensile tests proved to be remarkably higher than those predicted by Halpin–Tsai model, presumably due to the capability of the polymer to …

Statistical analysis of inter-arrival times of rainfall events for Italian Sub-Alpine and Mediterranean areas

2012

Abstract. In this work a set of time-series of inter-arrival times of rainfall events, at daily scale, was analysed, with the aim to verify the issue of increasing duration of dry periods. The set consists of 12 time-series recorded at rain gauges in 1926–2005, six of them belong to an Italian Sub-Alpine area (Piedmont) and six to a Mediterranean one (Sicily). In order to overcome the problem related to limited sample size for high values of inter-arrival times, the discrete probability polylog-series distribution was used to fit the empirical data from partial (20 yr) time-series. Moreover, a simple qualitative trend analysis was applied to some high quantiles of inter-arrival times as wel…

The endemic vascular flora of Peloritani Mountains (NE Sicily): Plant functional traits and phytogeographical relationships in the most isolated and …

2014

This study is aimed at (1) producing a complete and updated inventory of the endemic vascular flora of Peloritani Mountains, (2) defining the geographical limits of Peloritani, regarded here as a biogeographical district and (3) highlighting possible paleogeographic connections with other Mediterranean lands. The heterogeneity analysis of the endemic flora was performed by means of contingency tables, through the x 2 test. The endemic flora of this area consists of 129 specific and infraspecific taxa, of which 15 are restricted to the Peloritani Mountains. The analysis of habitats revealed that endemic taxa are most abundant on cliffs, rangelands, woods and garrigues. A large number of surv…

Brief an Karl Axel Christer Freiherr von Bruiningk

1839

Ms. 930a, Nr. 6b, Bl. 19r-19v Merkel, Garlieb H. Brief an Karl Axel Christer Freiherr von Bruiningk, [Depkinshof ?], [bez datuma; ohne Datum, pēc / nach 1839] Autora rokraksts / Autograph, vācu val. / Deutsch, [2] lpp. / S. Attēlu numuri / Bildnummern: 930a-006b-1 – 930a-006b-2 In dem undatierten Entwurf einer Antwort auf einen Brief Bruiningks [womit der unter Ms. 930a, Nr. 6a gemeint wird, bleibt noch unklar] lobt Merkel dessen Einsatz für die Bauernbefreiung. Das Problem des fehlenden Grundbesitzes für die freigelassenen Bauern sei ein Grund für die wirtschaftliche Rückständigkeit der „vaterländische[n] Provinzen“. Selbst in Posen (Preußen) und Galizien (Österreich) hätte die wirtschaftl…

Serpent and a hibris reporter are co-expressed in migrating cells during Drosophila hematopoiesis and Malpighian tubule formation

2006

Motile mesodermal cells contribute several cell types to developing embryos. In Drosophila, blood cell precursors or prohemocytes, are first detected in the procephalic mesoderm by the expression of the GATA transcription factor Serpent. Once specified, a subset of prohemocytes migrate posteriorly to populate most of the embryo and further differentiate as plasmatocytes. Similarly, Drosophila nephrogenesis involves integration of posterior mesodermal cells into the Malpighian tubule primordia where these cells differentiate as stellate cells. Here we investigated the possibility that the immunoglobulin-domain protein Hibris and the GATA factor Serpent were co-expressed in motile mesodermal …

An anomalous case in the evolution of the Mesozoic sedimentary basins between Alpine and Ionian Tethys: the Panormide Carbonate Platform (Sicily).

2007

Pseudosteppes and related grassland vegetation in the Pamir-Alai and western Tian Shan Mts – the borderland of the Irano-Turanian and Euro-Siberian r…

2020

The aim of our study was to complete the syntaxonomical scheme for grassland vegetation of the lowland, montane and alpine zones in the Pamir-Alai and western Tian Shan Mts in Tajikistan and Kyrgyzstan with some remarks on its environmental predictors. A total of 198 relevés were sampled in 2013–2018 using the seven-degree cover-abundance scale of the Braun-Blanquet approach. They were classified with k-means algorithm with tranforming cover values to three level scale of the following intervals 0%, 5% and 25% and total inertia as a measure of cluster heterogeneity. Diagnostic species were identified using the phi coefficient as a fidelity measure. Non-metric Multidimensional Scaling (NMDS)…