Beitrag zur kenntnis der waldgesellschaften der kleinen karpaten,slowakei I. Phytozönologische verhältnisse

In diesem Beitrag ist eine kurze Übersicht der Waldgesellschaften des Südteils der Kleinen Karpaten enthalten. Die ziemlich verschiedenen Standortsverhältnisse in diesem verhältnismässig kleinen Gebiete bedingen das Entstehen einer Reihe von Laubwaldgesellschaften mit sehr abweichenden Standortsansprüchen, wieCarici pilosae-Carpinetum, sekundärerPrimula-Eichen-Hainbuchenwald,Festuco heterophyllae-Quercetum, Stellario-Alnetum, Carici remotae-Fraxinetum, Dentario-Fagetum, Cephalanthero-Fagetum, Phyllitidi-Aceretum, Luzulo-Fagetum, Cotino-Quercetum pubescentis, Ceraso (mahaleb)-Quercetum undLuzulo-Quercetum. Den einzelnen Gesellschaften sind ihre phytozönotische Charakteristik und ein Schriftenvergleich beigefügt.     

Die Laubwaldgesellschaften des östlichen Teiles der Elbeebene,Tschechoslowakei

Diese Arbeit bringt Ergebnisse phytozönologisch-ökologischer Forschungen der Waldgesellschaften NO-Böhmens, des am rechten Elbeufer zwischen Hradec Králové-Městec Králové-Ji?ín und Ho?ice gelegenen Gebietes. Folgende Syntaxa wurden untersucht: dasGalio-Carpinetum Oberd. 1957 mit fünf Subassoziationen (colchicetosum, typicum, primuletosum veris, luzuletosum albidae, molinietosum arundinaceae), dasPotentillo albae-Quercetum Libb. 1933 (Ausbildungsform vonFestuca heterophylla), dasLuzulo albidae-Quercetum (Hilitzer 1932)Pass. 1953 emend. R. etZ. Neuh. 1967 und dasMolinio ar.-Quercetum R. etZ. Neuh. 1967 mit zwei Varianten (typische Var., Var. vonSphagnum). Eine besondere Aufmerksamkeit wurde den Standortsverhältnissen der unterschiedenen Syntaxa (bes. den physikalischen und chemischen Bodeneigenschaften) gewidmet.     

Effect of anatomical structure on the buoyancy of achenes of two subspecies ofBolboschoenus maritimus

Differences between two subspecies ofBolboschoenus maritimus (L.)Palla (=Scirpus maritimus L.) in different habitats (littoral and terrestrial) are partly due to variations in the buoyancy of their achenes, caused by different anatomical structure of the fruits. This hypothesis was tested by comparing fruit buoyancy and anatomy of both subspecies at several localities. Plants were sampled fromBolboschoenus maritimus subsp.maritimus (plants with branched inflorescences and triangular fruits, 4 localities) andB. maritimus subsp.compactus (Hoffm.)Hejný (plants with compact inflorescences and prevailing concave fruits, 4 localities) in the Czech and Slovak Republics, andB. maritimus subsp.compactus (plants with compact inflorescences and convex fruits, 1 locality) from the coast of South Sweden. From each locality a plant with several tubers connected by rhizomes was taken and transferred into the experimental garden; from these cultivated plants (clones) mixed samples of fruits collected from each clone were used for buoyancy tests and a study of their anatomy. Fruit buoyancy was found to depend on the anatomical structure of the pericarp—the presence of aeriferous tissue in the exocarp serves as the main floating organ. This differentiated all plants studied into two groups: short-floating subsp.maritimus, with a thin or none acriferous tissue in the exocarp, and long-floating subsp.compactus with well developed aeriferous tissue. Differences in fruit buoyancy corresponds to differences in the prevailing habitat types of both subspecies studied in the inland sites: the frequent occurrence of subsp.compactus in temporarily flooded terrestrial habitats contrasts with the prevalence of subsp.maritimus in the littoral of water bodies. This is an example of intra-specific ecological differentiation leading to differentiation in wetland communities.     

Vegetation of the Birjučij Island spit in the Azov Sea. Sand steppe vegetation

The syntaxa of the near-natural sand steppes (classFestucetea vaginatae) and their substitutes due to trampling (Chenopodietea) were studied in 1991 during the Ukrainian-Czech expedition to the Birju?ij Island Spit (Azov Sea, Ukraine). Within the allianceFestucion beckeri Vicherek 1972 (classFestucetea vaginatae Soó 1968 emend.Vicherek 1972, orderFestucetalia vaginatae Soó 1957) three associations and five communities without rank are described, covering the vegetation variability along gradients of sand stabilization/soil development and salinization/moisture. Further, two associations of the classChenopodietea, due to deer influence, are described. Four associations (Centaureo odessanae-Stipetum capillatae, Poo bulbosae-Caricetum colchicae, Secali-Cynodontetum dactyli andHeliotropio dolosi-Brometum japonici) are described as new.     

Weitere Versuche mit der Rauhverzwergung und Streifenkrankheit des Maises

P?i velmi pozdním setí (5. VI. 1964) a opakovaném p?enosu k?ísaCalligypona pellucida sOriganum vulgare aPlantato major, nemocných ?loutenkou aster, bylo u kuku?ice docíleno velmi ?etné a tě?ké napadení jmenovanou virosou. Onemocnění mělo za následek tmavou barvu list?, někdy jejich pruhovitost, ?asto zakrsání rostlin, nevyvinutí saměích květenství nebo jejich zlistnatění, rudimentární vývoj někdy nadměrně ?etných sami?ích květenství, jejich nedokonalé opylení, velmi silné sní?ení sklizně zrna. Na této lokalitě (Praha-Dejvice, Na Karlovce) nebylo docíleno ?ádné virové onemocnění p?enosemCalligypona pellucida na oves a je?men, jestli?e p?ed tím k?ísi sáli naOriganum vulgare z té?e lokality, nemocném ?loutenkou aster. Virosní sterilita a zakrslost ovsa je p?sobena jiným virem nebo jinou skupinou virových kmen? ne? virová zakrslost a pruhovitost kuku?ice.     

Sex-Dependent Changes in Striatal Dopamine Transport in Preadolescent Rats Exposed Prenatally and/or Postnatally to Methamphetamine

Methamphetamine (MA) is the most commonly used psychostimulant drug, the chronic abuse of which leads to neurodegenerative changes in the brain. The global use of MA is increasing, including in pregnant women. Since MA can cross both placental and haematoencephalic barriers and is also present in maternal milk, children of chronically abused mothers are exposed prenatally as well as postnatally. Women seem to be more vulnerable to some aspects of MA abuse than men. MA is thought to exert its effects among others via direct interactions with dopamine transporters (DATs) in the brain tissue. Sexual dimorphism of the DAT system could be a base of sex-dependent actions of MA observed in behavioural and neurochemical studies. Possible sex differences in the DATs of preadolescent offspring exposed to MA prenatally and/or postnatally have not yet been evaluated. We examined the striatal synaptosomal DATs (the activity and density of surface expressed DATs and total DAT expression) in preadolescent male and female Wistar rats (31–35-day old animals) exposed prenatally and/or postnatally to MA (daily 5 mg/kg, s.c. to mothers during pregnancy and lactation). To distinguish between specific and nonspecific effects of MA on DATs, we also evaluated the in vitro effects of lipophilic MA on the fluidity of striatal membranes isolated from preadolescent and young adult rats of both sexes. We observed similar changes in the DATs of preadolescent rats exposed prenatally or postnatally (MA-mediated drop in the reserve pool but no alterations in surface-expressed DATs). However, prenatal exposure evoked significant changes in males and postnatal exposure in females. A significant decrease in the activity of surface-expressed DATs was found only in postnatally exposed females sensitized to MA via prenatal exposure. MA applied in vitro increased the fluidity of striatal membranes of preadolescent female but not male rats. In summary, DATs of preadolescent males are more sensitive to prenatal MA exposure via changes in the reserve pool and those of preadolescent females to postnatal MA exposure via the same mechanism. The combination of prenatal and postnatal MA exposure increases the risk of dopaminergic deficits via alterations in the activity of surface-expressed DATs especially in preadolescent females. MA-mediated changes in DATs of preadolescent females could be still enhanced via nonspecific disordering actions of MA on striatal membranes.     

Exceptions in patterns of arsenic compounds in urine of acute promyelocytic leukaemia patients treated with As<Subscript>2</Subscript>O<Subscript>3</Subscript>

Arsenic trioxide (As(III) in solution) has been shown to be the most active single agent in combating acute promyelocytic leukemia (APL). It is metabolized and excreted via urine as monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) and As(V), along with excess As(III). In our study eight APL patients were treated (intravenously) with 0.15 mg As₂O₃/kg/day. During the therapy As(III) and its metabolites were followed in pre- and post-infusion urine using HPLC for separation followed by on-line detection using hydride generation-atomic fluorescence spectrometry. Five patients had a normal excretion pattern of residual arsenic compounds in morning pre-infusion urine, with 15–25 % of As(III), 35–55 % of DMA, 25–30 % of MMA and 1–5 % of As(V), while three patients showed unexpected exceptions from typical excretion patterns of arsenic compounds (i) a high DMA/MMA ratio (factor 5.3), (ii) severe As(III) oxidation (10.2 % As(III) converted to As(V)) or (iii) the presence of an excessive amount of As(III) (average 30.4 % of total arsenic). Intriguing was the occurrence of post-infusion oxidation of As(III) to As(V) observed in almost all patients and being especially high (>40 %) in patient with increased residual As(V). Results indicate that arsenic metabolites patterns can be unpredictable. Observed high levels of un-metabolised As(III) are a warning signal for side effects and for routine determination of arsenic metabolites during first days of treatment. High or low percentages of MMA or DMA did not show any observable effect on treatment results, while clear presence of post-infusion As(V) supports theoretical claims of in vivo oxidation (detoxification) of As(III) to As(V) associated with various metabolic processes.     

Clustering of the Metabolic Syndrome Components in Adolescence: Role of Visceral Fat

Visceral fat (VF) promotes the development of metabolic syndrome (MetS), which emerges as early as in adolescence. The clustering of MetS components suggests shared etiologies, but these are largely unknown and may vary between males and females. Here, we investigated the latent structure of pre-clinical MetS in a community-based sample of 286 male and 312 female adolescents, assessing their abdominal adiposity (VF) directly with magnetic resonance imaging. Principal component analysis of the five MetS-defining variables (VF, blood pressure [BP], fasting serum triglycerides, HDL-cholesterol and glucose) identified two independent components in both males and females. The first component was sex-similar; it explained >30% of variance and was loaded by all but BP variables. The second component explained >20% of variance; it was loaded by BP similarly in both sexes but additional loading by metabolic variables was sex-specific. This sex-specificity was not detected in analyses that used waist circumference instead of VF. In adolescence, MetS-defining variables cluster into at least two sub-syndromes: (1) sex-similar metabolic abnormalities of obesity-induced insulin resistance and (2) sex-specific metabolic abnormalities associated with BP elevation. These results suggest that the etiology of MetS may involve more than one pathway and that some of the pathways may differ between males and females. Further, the sex-specific metabolic abnormalities associated with BP elevation suggest the need for sex-specific prevention and treatment strategies of MetS.