Beiträge zur Ökologie des Aphano-Matricarietum Tüxen 1937

Zusammenfassung 1. An Hand von 101 Aufnahmen wird das Aphano-Matricarietum typicum and scleranthetosum im Unteren Eichsfeld in eine typische, eineRanunculus repens-, eineGnaphalium uliginosum-und eineJuncus bufonius-Variante gegliedert.2. Durch Bestimmungen des Bodenwassergehaltes und des pflanzenverfügbaren Wassers sowie durch Berechnung des W-Wertes nachEllenberg wird die Reihe der Varianten als Reihe zunehmender Feuchtigkeit charakterisiert.3. Bei zunehmender Dichte des Getreidebestandes nehmen die dominierenden Unkräuter stark ab, die schwach deckenden Unkräuter dagegen zu.4. Aus den Deckungswerten der soziologischen Tabelle werden Konkurrenzwirkungen zwischenMatricaria chamomilla, Aphanes arvensis undStellaria media belegt.

---

Summary 1. In two subassociations of a weed community (Aphano-Matricarietum typicum and scleranthetosum) 101 relevés are used for distinguish three subunits: a var. ofRanunculus repens, ofGnaphalium uliginosum and ofJuncus bufonius.By estimating the water contents and pF values of the soil and by calculating the water figure afterEllenberg this series of subunits is shown to be a series of increasing humidity.2. With increasing density of the cereal grasses, the stronger dominant weeds decrease, while the weaker ones increase.3. A method is described to calculate competition between the dominant weeds from the figures of the sociological relevés. Interactions have been found betweenMatricaria chamomilla at the one side andAphanes arvensis andStellaria media at the other side and vice versa.

     

Sodium Content of Community Water Supplies in California

The amount of sodium ion in water used for ingestion may be critical in effective use of a low sodium dietary regimen. Waters containing not over 20 mg of sodium per liter are provided for in the sodium restricted diets set forth by the American Heart Association. For diets containing more than 500 mg of sodium a day, waters of greater sodium content may be used if proper dietary adjustments are made.While assessment of the long-term average sodium content of a community water supply is difficult, the determined values for sodium lend to classification within range categories. The larger community water supplies in California are presented within several range categories of sodium content.The more commonly used water softeners add sodium to water. The sodium-restricted patient should be cautioned against their use. Similar consideration should probably be given to water supplies of retirement communities where the potential for disorders requiring sodium restriction is greater than in the general population.     

Luciferin derivatives in bioluminescence-enhanced enzyme immunoassays

Ultrasensitive bioluminescence immunoassays for the determination of peptides and proteins (illustrated with human urinary kallikrein, bradykinin and the determination of human urinary kallikrein antibody titres) have been developed. The usable ranges of the standard curves are from 5 pg to 5000 pg per litre. The relative intra-assay coefficients of variation of the tests were between 2% and 6%, and the inter-assay coefficients of variation between 4% and 12%.     

Cuticle ultrastructure of Hesionid polychaetes (Annelida)

Summary The structure of the cuticle in the four species of the family Hesionidae(Microphthalmus cf.listensis, M. cf.similis, Hesionides arenaria, juv.Podarke spec.) investigated basically corresponds to that found in all annelids. It consists of an outer, electron dense layer, epicuticle, basal cuticle with a fibrous layer, and numerous microvilli which penetrate the layers and are covered by a more or less dense glycocalyx. However, a rough collagen grid is not developed, the fibers are much thinner and are arranged in a more irregular manner. This corresponds to structures found in archiannelids and polychaete larvae. We consider them here to be reductions of the typical polychaete cuticle and postulate a correlation to the small body size of the species investigated. The quantitative differences in cuticle dimensions in the various body regions and structures can also be explained on a purely functional basis, especially apparent in the comparison of prostomium and body trunk. The pharynx cuticle shows significant structural differences due to the development of an additional peripherical lamellar layer-known to this extent only in gastrotrichs—as well as differently shaped and unusually long microvilli. This character is discussed as a possible synapomorphy for the family Hesionidae.

---

Zusammenfassung Der Aufbau der Kutikula der 4 untersuchten Species aus der Familie Hesionidae(Microphthalmus cf.listensis, M. cf.similis, Hesionides arenaria, juv.Podarke spec.) entspricht grundsätzlich den Verhältnissen bei allen Anneliden: äußere elektronendichte Schicht, Epikutikula, basale Kutikula mit Faserschicht und zahlreiche Mikrovilli, die diese Schichten durchbrechen und von einem mehr oder weniger dichten Glykokalyx bedeckt sind. Ein derbes Kollagengitter ist jedoch nicht ausgebildet; die Fibrillen der Faserschicht sind wesentlich feiner und unregelmäßiger angeordnet. Dies entspricht Strukturen, wie sie bei Archianneliden und bei Polychaetenlarven gefunden werden. Wir deuten sie hier als Reduktionen der typischen Poly chaetenkutikula und vermuten eine Beziehung zur geringen Körpergröße der untersuchten Arten. Rein funktionell lassen sich auch die quantitativen Unterschiede in den verschiedenen Bereichen der Körperoberfläche deuten, die besonders im Vergleich von Prostomium und Rumpf zum Ausdruck kommen. Die Pharynxkutikula zeigt starke strukturelle Abweichungen durch die Ausbildung einer zusätzlichen peripheren Lamellenschicht (in diesem Ausmaß nur von den Gastrotrichen bekannt) und abweichend geformter, besonders langer Mikrovilli. Dieses Merkmal wird als mögliche Synapomorphie für die Familie Hesionidae diskutiert.

     

Cholinergic Control of Nerve Growth Factor in Adult Rats: Evidence from Cortical Cholinergic Deafferentation and Chronic Drug Treatment

Abstract: It is well documented that nerve growth factor (NGF) plays an important role in maintaining functions of cholinergic basal forebrain neurons. In the present study, we tested the hypothesis that cholinergic activity controls NGF levels in cholinoceptive neurons of the cerebral cortex and hippocampus. To address that question, we used both cholinergic deafferentation of cerebral cortex and hippocampus by cholinergic immunolesion with 192IgG-saporin and chronic pharmacological treatment of sham-treated and immunolesioned rats with the cholinergic agonist pilocarpine and the cholinergic antagonist scopolamine. We observed an increase in NGF protein levels in the cortex and hippocampus after cholinergic immunolesions and also after muscarinic receptor blockade by chronic intracerebroventricular scopolamine infusion in sham-treated rats after 2 weeks. There was no further increase in the accumulation of NGF after scopolamine treatment of immunolesioned rats. Chronic infusion of pilocarpine had no effect on cortical and hippocampal NGF protein levels in sham-treated rats. In rats with cholinergic immunolesions, however, pilocarpine did prevent the lesion-induced accumulation of NGF. There was no effect of cholinergic lesion and drug treatment on cortical or hippocampal NGF mRNA levels, consistent with the importance of NGF retrograde transport as opposed to its de novo synthesis. This study provides strong evidence for the hypothesis that there is cholinergic control of cortical and hippocampal NGF protein but not mRNA levels in adult rats.