Variazioni delle popolazioni di microfunghi del suolo durante il post-incendio di Monte Argentario

Abstract

Post-fire sequences in microfungal soil populations in Mount Argentario (Toscana region). A research program was conducted to investigate the post-fire sequences of microfungal populations in Thyrrenian Coastal soils. This paper reports the results of the first year of that study. An initial reduction of fungi was followed by a gradual reconstruction process characterized by a constant increase of colonies and species. The periodic after fire analysis permitted an initial understanding of the possible selective role of the fire and its consequences on some microfungal species.     

Microfunghi del suolo di aree floristicamente omogenee di tre cenosi boschive delle Prealpi bellunesi

Abstract

Soil microfungi in homogeneous areas of three plant communities of North Italy.—The soil microfungi associated with three different community types in Prealpine region of North Italy were investigated. Frequency values for the taxonomic entities isolated were calculated, based on occurrence at sampling sites, in each community. Most of the entities were quantitatively rare. The microfungal communities associated with Acer pseudoplatanus and Fraxinus excelsior, with Ostrya carpinifolia and with Fagus sylvatica appeared to be a distinctive group, even if many of them contained a substantial number of species wich are common with other vegetation types.     

Costanza numerica delle cellule di purkinje del cervelletto dell'uomo in individui di varia eta'

Zusammenfassung Es wurde an mikrotomischen Schnitten des Kleinhirns die Zahl der Purkinjeschen Zellen pro mm Länge bei 10 Menschen von verschiedenem Alter (von 6–88 Jahren) berechnet; für jeden Fall wurden etwa 16000–18000 Zellen berechnet. Im Gegensatz zu den Ergebnissen von Ellis habe ich keine Abnahme der Zellenzahl mit fortschreitendem Alter beobachtet; die Variationen der Zellenzahl waren unbedeutend und standen jedenfalls keineswegs in Beziehung zu dem Alter; bei 6jährigen Kindern waren die erhaltenen Werte etwas höher, d. h. waren die Zellen dichter; dies ist erklärlich, wenn man bedenkt, daß bei Kindern trotz der geringeren Größe des Kleinhirns die Zahl der Neuronen ebenso groß ist als beim Erwachsenen.     

I muscoli metamerici delle larve di anuri e la teoria segmentale del Loeb

Il presente lavoro è stato eseguito nell' Istituto di Anatomia e Fisiologia Comparate dell' Università di Palermo, diretto dal prof. F.Raffaele. Il manoscritto relativo era pronto fin dall' ottobre dell' anno passato, ma il mio trasferimento da Palermo a Pavia e varie altre circostanze mi avevano finora impedito dal darvi l'ultima mano.Al prof.Raffaele che ha seguito con efficace interessamento queste ricerche e che ha voluto adesso gentilmente rivedere anche il manoscritto, i miei più cordiali ringraziamenti.     

Analisi polliniche di depositi lacustri delle pendici del M. Vulture in Basilicata

Abstract

Pollen analysis of lake sediments on Mt. Vulture in Basilicata (Southern Italy).—A marshy sediment, about 7 meters thick, containing fossil pollen, has been discovered in a little lake of volcanic origin on a slope of Mount Vulture in Lucania at 656 m above sea level.

The sediment shows four distinct layers from the top to the bottom. The deepest layer, from 7 to 5.75 m, consisting of clay containing Betula and Ostrya, indicates a rather arid climate; the next layer, from 5.75 to 3.75 m, made up of mud rich in organic substance and containing pollen of Fagus and Abies, is witness of a damp and warmer climate; the following layer, from 3.75 to 2.25 m, with clay containing Betula, Ulmus, Ostrya and Corylus suggests a return to a more arid climate; lastly, the upper layer, from 2.25 m to the surface, with marshy mud rich in organic substance and pollen of plants with greater water requirements leads us to think of a return to a damper climate.     

Modificazioni isto-fisiologiche delle cellule vescicolose di bizzozero del midollo osseo in seguito a salassi

Zusammenfassung Die sogenannten serösen oder bläschenförmigen Zellen des Knochenmarks (Bizzozero) des stark verhungernden Kaninchens sind bekanntlich Fettzellen, in denen das Fett verbraucht wurde; in denselben habe ich nie weder Speicherung vitaler Farbstoffe, beobachtet, noch andere Merkmale, welche auf eine Umwandlung in Histiozyten hindeuten. Wenn dagegen bei diesen Tieren mehrfach Blut entnommen wurde, wandeln sich die serösen Zellen in typische Histiozyten; ihre Form wird unregelmäßig, mit zahlreichen Fortsätzen, in Beziehung mit dem Reticulum des Knochenmarks; das Zytoplasma dieser Zellen speichert Trypanblau in erheblicher Menge und erscheint mit Hämosiderinkörnchen beladen. Ich vermute deshalb, daß in den serösen Zellen des Knochenmarks die latenten histiozytären Eigenschaften durch den hämopoietischen Reiz erweckt werden.     

La partecipazione del mesenchima alla morfogenesi delle ghiandole. Ricerche sperimentali sulla ghiandola di Harder

Zusammenfassung Durch frühzeitige Zerstörung der ganzen primären Augenblase, bzw. des oberflächlichen Abschnittes der Augenanlage mit dem anliegenden Ektoderm, wurde beim Hühnerembryo die Entwicklung des ektodermalen Bestandteiles derHarderschen Drüse verhindert. Trotzdem legte sich der mesenchymale Bestandteil der Drüse an normaler Stelle an und entwickelte sich normal bis zum Ausschlüpfen; nur war die ausschließlich aus Mesenchym zusammengesetzte Anlage etwas kleiner als die normale Drüse. Vom 10. Tage der Bebrütung ab erscheint bei den operierten Embryonen der bindegewebige Bestandteil der Drüse als eine scharf konturierte, von den anliegenden Geweben gesonderte Masse von länglicher Form. Vom 16. Tage der Bebrütung ab dringen in die bindegewebige Masse kleine runde, stark granulierte Wanderzellen (vielleicht Makrophagen) ein; dasselbe wurde in der normalen Drüse beobachtet.Dadurch wird das Bestehen einer relativen Unabhängigkeit zwischen den beiden Bestandteilen derHarderschen Drüse, dem epithelialen und dem mesenchymalen Anteil, bewiesen; die Vermutung liegt also nahe, daß eine gewisse Unabhängigkeit in der Determination der beiden bestehe.     

Analisi informazionale degli schemi di dinamica della vegetazione. Un esempio sul popolamento vegetale delle dune del litorale di Venezia

Abstract

A method to quantify the dynamic schemes of vegetation based on information functions.—The dynamic schemes of vegetation as proposed by Braun-Blanquet have been never quantified with the aim to give indirect measures of the probability of transition between the types. This work presents a method that quantifies the arrows between the types by means of a redundancy measure. This is calculated by comparing the phytosociological types two by two. Redundancy, as proposed here, measures the similarity between the tables not only based on species composition but also on the basis of species cooccurrence. The method relies on the assumption that in a succession the higher is the redundancy between the types, that are presumably in sequence, the higher is the probability and then the velocity of transition from one type to another one. An example is given with data from coastal dune grasslands of the Venice Lagoon.     

Ricerche ultrastrutturali sulla distribuzione del glicogeno nelle cellule dell'embrione di pollo in rapporto alla presenza delle inclusioni vitelline

Riassunto L'autore ha condotto uno studio al microscopio elettronico sulla distribuzione e sulla genesi del glicogeno nelle cellule dell'embrione di pollo nei primi stadi dello sviluppo.L'autore riscontra che nelle prime ore di incubazione il glicogeno è presente in pressochè tutte le cellule del blastoderma, dove coesiste con inclusioni vitelline. Al 2° giorno di incubazione il glicogeno scompare in tutte le cellule che hanno interamente digerito le inclusioni vitelline, rimanendo invece solo in quelle che sono ancora rieche di vitello. Fanno eccezione le cellule del miotoma che, pur essendo sprovviste di vitello, nella terza giornata di incubazione accumulano glicogeno in notevole quantità, in coincidenza con la comparsa in esse délie miofibrille.L'autore ritiene ehe il glicogeno che si trova inizialmente nelle cellule embrionali si formi in gran parte per attività neoglicogenetica, a partire dal vitello contenuto nelle cellule medesime, Egli conclude che tale attività neoglicogenetica dapprima sia propria di tutte le cellule embrionali, fino a quando hanno inclusioni vitelline, e che poi essa rimane localizzata al solo epitelio del sacco vitellino che sempre contiene vitello.

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Ultrastructural investigations on the distribution of glycogen in the cells of chick embryo in relation to the presence of yolk inclusions

Summary The distribution and genesis of glycogen in the embryonic cells of chickens in the first stages of development has been investigated electronmicroscopically.In the first hours of incubation the glycogen is present in almost all the cells of the blastoderm where it coexists with yolk inclusions. On the second day of incubation the glycogen disappears in all the cells that have completely digested the yolk inclusions and remains only in those that are still rich in yolk. The only exceptions are the myotome cells that, being that they do not have yolk in the third day of incubation, accumulate glycogen in notable quantities coincidental to the appearance of myofibrils.The author holds that the glycogen that is found initially in the embryonic cells has its origin, for the most part, from neoglycogenetic activity, starting from the yolk contained in the cells themselves. It is concluded that this neoglycogenetic activity initially is present in all the embryonic cells, while they still have inclusions, and then remains localized only in the epithelium of the yolk sac that always contains yolk.

     

Topografia delle cellule di Kupffer e Thorotrast

Zusammenfassung Verf. erläutert einen noch nicht geschilderten morphologischen Befund. Während der bei Kaninchen mit Thorotrast ausgeführten Speicherungsuntersuchungen des retikulär-endothelialen Systems hat er beobachten können, daß die Kupffer-Sternzellen bei seit langer Zeit behandelten Tieren aus ihrem normalen Sitz im hepatischen Acinus gegen seine zentrale Ader gewandert sind, indem sie um dieselbe einen Umkreis von mit Thorotrast belasteten Kupffer- Sternzellen bildeten und indem sie auch in das Leberaderblut eindrangen. Dagegen findet man bei seit kurzer Zeit behandelten Tieren die mit Thorotrast belasteten Zellen im Acinus, wie gewöhnlich, diffus verteilt. Verf. erörtert diese Befunde im Zusammenhang mit der Bedeutung und dem Wesen der KupfferSternzellen.     

Primi Processi di Germinazione in Pinus Pinea L. var. Fragilis Du Hamel

Abstract

Early stages of germination in PINUS PINEA L. var. FRAGILIS Du Hamel. — The main stages of the hydration process preceeding germination and accompaning root elongation have been observed in Pinus pinea L. seeds, by means of vital colours (Congo red, neutral red, acid fuchsine).

The results are as follows:

a) water penetrates easily through the outer shell of the seed reaching its deepest layer which is less permeable to water. Two or three days were required in our experience for water could overcome this barrier.

b) The inner shell (known as « soft shell ») is almost water-proof and seems to draw water towards the micropilar pole of the seed, so that the first region of the seed which sucks up water is the micropile.

c) Through the micropile water enters the seed and imbibes the column, the pericolumn and the endosperm cells.

The endosperm swells with water until the seed shell blows up, because of the inside pressure. At this time water freely penetrates the seed everywhere.

In natural conditions we may infer that the first tissues which take contact with the soil water are the column and pericolumn. As a certain amount of time is required for penetration of water as far as the column (two or three days in experience conditions) germination starts only after a given amount of water is available in the soil for a certain period of time.

When seed hydration is performed the embryo root starts elongating and gets out of the seed.

The behaviour of the column, the pericolumn and the root cap during the early stages of germination are dexcribed.     

Inquadramento fitosociologico delle leccete dei dintorni di Siena

Abstract

A phytosociological study of the Quercus ilex woods in the surroundings of Siena (Italy). – Numerous stands of Quercus ilex woods around Siena have been studied phytosociologically and compared to the better known similar forests of Southern France. As a rule the Siennese Quercus ilex woods (Table 1) can not be considered to belong to the association Quercetum mediterraneo-montanum Br.-Bl. 1936 because of the absence of various significant central European and montane species, nor to Quercetum galloprovinciale because of the presence of too great a number of Quercetalia pubescenti-petraeae and Querco-Fagetea species. Only rarely communities similar to the first mentioned association have been found: i.e. on Mount Cetona at 1.800 feet and in two particularly cool and humid localities at a lower height (Table 2). Taking into account the way these woods have been managed for centuries it can be concluded that they are mixed formations of Quercetum galloprovinciale and an oakwood association belonging to the order Quercetalia pubescenti-petraeae; the exploitation techniques have caused the evergreen oak to become dominant therefore creating conditions favourable to the more thermophilous and shade loving plants characterics of Q. ilex woods and at the same time bringing about a sharp decrease in the number of the light demanding species typical of deciduous oakwoods.     

Il tipo delle Dicotiledoni e il tipo delle Monocotiledoni nella formazione del vero periplasmodio nella famiglia delle Lauraceae

Raissunto

Nella famiglia delle Lauraceae è stata fino ad oggi riconosciuta la formazione di un vero periplasmodio nei due generi Sassafras e Cinnamomum. Il periodo e le modalità di sviluppo fanno riferire il primo al tipo che si osserva nelle Monocotiledoni, il secondo a quello delle Dicotiledoni. Nei due tipi alcune particolarità morfologiche permettono induzioni sul significato fisiologico del periplasmodio.