Hongos queratinofílicos en suelos de parques de la ciudad de Corrientes,Argentina

BackgroundThe soil is a natural reservoir of keratinophilic fungi, which are a small but important group of filamentous fungi, some of which typically develop on keratinized tissues of living animals. There are numerous species of saprophytic fungi with recognized keratinophilic abilities, and several studies have been undertaken in order to link their presence to possible human disease.AimsTo know the biota of geophilic fungi in general and of keratinophilic fungi particularly in soils from two public parks.MethodsSoil samples from two public parks of Corrientes city, Argentina, were studied during two seasons, using the hook technique and serial dilutions for fungal isolation.ResultsUsing the hook technique, 170 isolates were classified into 17 genera and 21 species, among which it is worth mentioning the presence of Microsporum canis. Shannon index for keratinophilic fungi in autumn was 2.27, and 1.92 in spring. By means of the serial dilutions technique, 278 fungi isolated were identified into 33 genera and 71 species. Shannon index in autumn was 3.9, and 3.5 in spring.ConclusionsThe soils studied have particularly favorable conditions for the survival of pathogens and opportunistic geophilic fungi for humans and animals.     

Vegetación briofítca de las sierras de Filabres,Cabrera, Alhamilla y Cabo de Gata (Almería,SE de España)

The bryophyte vegetation of the Almería Province (SE Spain) has been studied according to the Braun-Blanquet method. Twenty-nine communities have been recognized, of which four are aquatic (classes Montio-Cardaminetea Braun-Blanquet & Tiixen 1943 and Platyhypnidio-Fontinalietea antipyreticae Philippi 1956), five terricolous acidophilous (classes Ceratodonto-Polytrichetea piliferi Mohan 1978 and Dicranelletea heteromallae Mohan 1978), 15 terricolous basiphilous (class Barbuletea unguiculatae Mohan 1978), four saxicolous (classes Racomitrietea heterostichi Neumayr 1971, Grimmietea anodontis Hadac & Vondraček in Jezek & Vondraček 1962 and Neckeretea complanatae Marstaller 1986) and one epiphytic (class Frullanio-Leucodontetea sciuroidis Mohan 1978 emend. Marstaller 1985). Three associations have been described as new: Rhizomnio punctati-Fissidentetum taxifolii (meso-hygrophilous, sciophilous, terri-humicolous, edaphically indifferent, on slopes close to running water), Plagiochasmo rupestris-Athalamietum spathysii (xerophilous, photo-sciophilous, chasmo-comophytic, basiphilous, in deep cavities of volcanic and sedimentary rocks) and Homalothecio aurei-Scleropodietum touretii (meso-xerophilous, photo-sciophilous, terricolous, edaphically indifferent, in rocks and humiferous slopes). Studies of the dynamics of the communities were undertaken.     

Lutte biologique contre les mollusques vecteurs de Bilharziose. Action predatrice de Tilapia rendalli,Boulenger et de Sarotherodon mossambica,Peters a l'égard de Biomphalaria glabrata,Say

Laboratory experiments indicate that the Cichlidae Sarotherodon mossambica and, mainly, Tilapia rendalli may be promising biological control agents of Schistosomiasis by acting as predators of eggs and young Biomphalaria glabrata less than 10 mm diameter.

     

Influence comparée de l'(±)-acide abscissique,de la coumarine,de l'acide p-coumarique et de certains de leurs dérivés sur la croissance de la première feuille de blé

Summary The activities of (±)-abscisic acid and a number of compounds derived from p-coumaric acid and coumarin and their interaction with gibberellic acid in the control of the elongation of the first wheat leaf are examined. (±)-Abscisic acid strongly inhibits leaf growth in the presence as well as in the absence of gibberellic acid, but the inhibition is greater in the presence of gibberellic acid (3 g/l already have an observable effect). Among other compounds, only ferulic acid and coumarin significantly reduce leaf elongation, and they are effective only at high concentrations (1.44 · 10^-4 M/l).     

Etude histochimique de quelques hydrolases lysosomiques de l'épithélium intestinal,au cours du développement de la larve de Discoglossus pictus Otth,Amphibien Anoure

Résumé Dans l'épithélium intestinal de la larve du discoglosse, nous avons recherché par le microscope électronique les activités de trois enzymes lysosomiques: la phosphatase acide, la thiolacétate-estérase et l'aryl sulfatase.Avant le climax de la métamorphose, l'activité phosphatasique acide se localise dans des corps au diamètre inférieur au micron, présents dans la zone supranucléaire de l'épithélium primaire. Durant la période climacique (émergence du premier membre antérieur), le produit de réaction diffuse depuis ces lysosomes et occupe le hyaloplasme environnant. Des aires d'autolyse aux limites imprécises apparaissent alors dans l'épithélium. A leur voisinage, on reconnaît de nombreuses vacuoles autolytiques, aux dimensions variées et en général phosphatase acide-positives; elles sont accompagnées de leurs formes d'évolution (corps résiduels) enrichis en tourbillons membranaires; les plus grandes de ces vacuoles pourraient naître après encerclement des aires d'autolyse diffuse. En fin de climax, le phosphate de plomb envahit tout le hyaloplasme, cependant que des fragments cellulaires dégénérés se remarquent dans la lumière de l'organe. Au contraire, l'épithélium secondaire de remplacement est toujours dépourvu du produit de réaction.La mise en évidence des activités thiolacétate-estérasique et aryl sulfatasique confirme la nature lysosomique des corps supranucléaires et des vacuoles autolytiques de l'épithélium primaire.

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Histochemical study of some lysosomal hydrolases of the intestinal epithelium during the development of the tadpole of Discoglossus pictus otth, anuran amphibianII. Observation with the electron microscope

Summary In the intestinal epithelium of the tadpole of the discoglosse, we have analysed the activities of three lysosomal enzymes: acid phosphatase, thiolacetate-esterase and arylsulphatase with the electron microscope.Before the climax of the metamorphosis, the acid phosphatase activity is localized in bodies smaller to one micron in diameter, which are observed in the primary epithelium supranuclear cytoplasm. During the climax (emergence of the first fore-leg), the reaction product diffuses itself from these lysosomes and occupies the surrounding hyaloplasm. Then, autolytic unprecise-limited areas appear in the epithelium. In their neighbourhood, many, more or less large and acid phosphatase-positive, autolytic vacuoles are recognized; they are surrounded by their residual bodies enriched with membrane whorls; the larger vacuoles might appear after segregation of diffuse autolytic areas. At the end of the climax, the lead phosphate invades the whole hyaloplasm; in the meanwhile, cellular degenerated bits are to be seen in the intestinal lumen. On the contrary, the secondary epithelium replacing the primary is always devoid of the reaction product.The visualization of the activities of thiolacetate-esterase and arysulphatase confirms the lysosomal nature of the supranuclear bodies and the autolytic vacuoles of the primary epithelium.

     

Effets de la température sur la croissance de deux algues vertes du fleuve St-Laurent,secteur de Gentilly,Québec

Two abundant phytoplankters from the St-Lawrence river: Scenedesmus spinosus Chodat 1913 and Pediastrum boryanum (Turp.) Menegh (Chlorophyta, Chlorococca) were sampled, isolated and cultured in monospecific culture. Growth responses were measured after acclimation to different temperatures and after thermal shock treatments.Post-acclimation specific growth rates followed similar patterns with optimal temperatures at about 24°C (S. spinosus) and 26°C (P. boryanum). Final densities were much less influenced by temperature in S. spinosus than in P. boryanum. Post-treatment responses depended on the temperature level maintained after treatment rather than on treatment conditions. No treatment seemed to delay the exponential growth phase. The time needed to reach final densities corresponding to stationary growth phase was not influenced by any thermal treatment. In situ thermal effects at Gentilly nuclear site could be more severe, due to differences in time-temperature history experienced by the algae.

     

Variations de quelques aclivités enzymatiques (peroxydase, catalase, AIA-oxydase) et de la teneur en polyphénols au cours de la germination de I'Orge. Influence de la kinétine

Peroxidase catalase, IAA-oxidase and polyphenol content of growing barley coleoptile. Effect of kinetin. - Kinetin strongly inhibits root and coleoptile growth of germinating barley in the dark. Treated coleoptiles become senescent before the untreated ones. Soluble proteins content, peroxidase, catalase and IAA-oxidase activity were greatly increased in treated coleoptiles while the level of polyphenols was reduced. These biochemical effects joined with the other property of kinetin to diminish α-amylase synthesis in the endosperm are discussed in relation to growth and in connection with the classic view of a cytokinin retarded senescence.     

La photooxydation du cytochrome b-559, en presence de carbonylcyanure-p-trifluorométhoxyphenylhydrazone et de 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone,ou de p-benzoquinone,chez trois mutants non-photosynthétiques de Chlamydomonas reinhardti

Cytochrome b-559 photooxidation in the presence of carbonyl cyanide p-trifluorometh-oxyphenylhydrazone and 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone or p-benzoquinone in three non-photosynthetic mutants of Chlamydomonas reinhardtiStudies of absorbance changes related to the cytochrome b-559 photooxidation induced by FCCP, with and without addition of 3-p-chlorophenyl-1, 1-dimethylurea (CMU), DBMIB or p-benzoquinone, in whole cells and in chloroplast fragments of Chlamydomonas reinhardti, were carried out. In addition to the wild type, three strains of non-photosynthetic mutants were used: Fl 5, which lacks P 700; Fl 9 and Fl 15, which are deficient in bound cytochrome c-553 and in cytochrome b-563.In the presence of FCCP, whole cells and chloroplast fragments of the four strains showed a System II-dependent photooxidation of cytochrome b-559. This photooxidation was inhibited by CMU but it occurred again in presence of FCCP, CMU and DBMIB. In chloroplast fragments, cytochrome b-559 photooxidation was also inhibited by an excess of FCCP; it was recovered, likewise, by addition of DBMIB. In whole cells, the highest measured redox changes were: 1 μmol oxidized cytochrome b-559 per 1 mmol chlorophyll, corresponding approximately to about one seventh (wild type, Fl 5) or one fifth (Fl 9, Fl 15) of the total amount of this cytochrome.Another kind of cytochrome b-559 photooxidation, CMU-insensitive, also occurred in the mutants Fl 9 and Fl 15 and in the wild type, but not in the mutant Fl 5. This latter kind of photooxidation was observed with chloroplast fragments in the presence of FCCP and CMU and also with whole cells in the presence of FCCP, CMU and p-benzoquinone. These reactions can be attributed to the Photosystem I; they do not require the intervention of the cytochrome c-553.A high-potential form of cytochrome b-559, hydroquinone-reducible, was involved in these two kinds of photooxidation. In addition, a lower potential form, reducible only by ascorbate, appeared to be able to interfere also.An interpretation is attempted, taking into consideration the various effects of FCCP and DBMIB, at different concentrations, on photosynthetic electron transport.     

Etude histochimique de quelques hydrolases lysosomiques de l'épithélium intestinal,au cours du développement de la larve de Discoglossus pictus Otth,Amphibien Anoure

Résumé Nous avons étudié au microscope photonique les activités de cinq enzymes lysosomiques de l'épithélium intestinal, lors du développement larvaire d'un Amphibien Anoure, Discoglossus pictus Otth. Nous avons visualisé ces activités par le sulfure de plomb (phosphatase acide et thiolacétate-estérase), le sulfate de baryum en contraste de phase (aryl sulfatase) ou par un colorant azoïque (phosphatase acide, -glucuronidase et N-acétyl--glucosaminidase). Avant le climax de la métamorphose, le produit de réaction reste localisé à de petits granules de l'espace supranucléaire. Il envahit l'épithélium primaire au moment du climax (émergence du premier membre antérieur), durant lequel cette assise subit une histolyse. Ce produit est alors présent dans de nombreux corps aux dimensions élevées, assimilables à des cytolysomes (vacuoles autolytiques) ou à des cellules altérées; parfois on le décèle à l'état diffus dans le hyaloplasme. L'épithélium secondaire qui se substitue au primaire ne montre en général aucune activité enzymatique. L'intensité de la réaction varie aussi selon l'enzyme; en particulier, elle demeure faible pour la -glucuronidase mais élevée pour la N-a--glucosaminidase.

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Histochemical study of some lysosomal hydrolases of the intestinal epithelium during the development of the tadpole of Discoglossus pictus Otth, anuran amphibianI. Observation with the light microscope

Summary We have studied with a light microscope the activities of five lysosomal enzymes of the intestinal epithelium, during the development of the tadpole of an Anuran Amphibian, Discoglossus pictus Otth. We have visualized these activities by lead sulfide (acid phosphatase and thiolacetate-esterase), barium sulphate with a phase contrast microscope (arylsulphatase) or by an azo-dye (acid phosphatase, -glucuronidase and N-acetyl--glucosaminidase). Before the climax of the metamorphosis, the reaction product is localized in little granules of the supranuclear cytoplasm. It invades the primary epithelium during the climax (emergence of first fore-leg), while a histolysis of the primary epithelium can be observed. Then this product can be seen in many large bodies which can be explained as cytolysomes (autolytic vacuoles) or as disorganized cells; sometimes too, it can be found in the hyaloplasm. Generally, the secondary epithelium which takes the place of the primary one does not show any hydrolytic activity. The intensity of the reaction also varies with the enzyme; in particular, it remains slight with the -glucuronidase but high with the N-a--glucosaminidase.

     

Reproduction de l'Omble de fontaine,Salvelinus fontinalis (Mitchill), dans des lacs de différents pH

Mn, Fe, Cu, and Cd concentrations are reported for Lake Vanda, a closed-basin, meromictic, Antarctic lake and for its single major inflow, the Onyx River. Trace metal distributions in the upper lake and annual metal fluxes from the Onyx River were used to estimate chemical residence times in the mixed zone above the chemocline. Residence times, based on total metal loads, were 9.4 years for Mn; 1.4 years for iron; 174 years for copper; and 82 years for cadmium. Controls on the steady state concentrations of metals in this system are likely to include: particle settling of Fe and Mn; scavenging of minor elements on metal oxide surfaces; sulfide precipitation from the anoxic brine; and possibly uptake of metals on the surface of benthic algal mats. Model calculations show that metal removal by sinking phytoplankton can account for only a small fraction of the annual loss.     

Una nueva especie de Chusquea (Poaceae: Bambusoideae) de la Cordillera de Mérida, Venezuela

A new species of woody bamboo (Poaceae: Bambusoideae),Chusquea guirigayensis, is described and illustrated. This species is placed inChusquea sect.Swallenochloa (McClure) L. G. Clark because of its shrubby habit, short waxy internodes, intravaginal branching, and linearly arranged subsidiary buds/branches. In addition, we discuss related species, and describe the ecology and distribution of the new species. Separate keys based on sterile and fertile material of the Venezuelan species ofC. sect.Swallenochloa are provided.     

Hemicyon mayorali nov. sp., Ursidae du Miocène moyen de Tarazona de Aragon (bassin de l'Ebre,Aragon, Espagne)

Study of a new species of an ursid, Hemicyon mayorali of Tarazona de Aragon in Spain. This species differs from the other species of the genus by the lengthening of the snout and the morphology of M2.     

Charles de Gerville et les premiers restes de Plesiosauria signalés dans le Jurassique inférieur de France (Hettangien,région de Valognes,Manche)

The historian, archaeologist, and naturalist Charles de Gerville (1769–1853) reported as early as January 1816 the presence of fossil bones in the quarries of the region of Valognes, in the department of Manche. These quarries exploited the “Calcaire de Valognes” and the underlying “Argiles et Calcaires d’Huberville”, both formations dated as Lower Hettangian (Lower Jurassic). De Gerville communicated to Jacques-Louis-Marin Defrance a watercolour drawing of one of these fossil bones, discovered in July 1820, in which it is possible to recognize a plesiosaur femur. This femur, as well as a fragment of rib and three vertebrae of Plesiosauria from de Gerville's collection, was then figured in a publication by Arcisse de Caumont, in 1825. The plesiosaur femur was later acquired by Pierre Tesson of Caen, who owned one of the most important collections of fossils in Normandy. The Tesson collection was later purchased in 1857 by the British Museum (now The Natural History Museum, London), where the femur has been rediscovered. This specimen is the first known plesiosaur specimen ever discovered in the Lower Jurassic of France, before the genus Plesiosaurus was established upon material from the Lias of southwestern England. One of the vertebrae figured by de Caumont has been rediscovered in the “Muséum Emmanuel-Liais” (Cherbourg-en-Cotentin), which had acquired part of de Gerville's collection. The interpretation of the “fossil bones of Valognes” by Georges Cuvier, Henri Marie Ducrotay de Blainville, Arcisse de Caumont, Jacques-Amand Eudes-Deslongchamps and Constant Duméril is revealed through unpublished documents.     

Étude,en cryodécapage,de la morphologie des surfaces lamellaires chloroplastiques de Chlorella pyrenoidosa,en cultures synchrones

Summary The structure of synchronized cells of Chlorella pyrenoidosa was investigated using the freeze-etching method.The report presents some various cell stages showing especially successive aspects of chloroplasts, of the vacuolar system and of some membranous and lamellar structures (nuclear, partition and thylakoid membranes) during the life cycle of the algae.Lamellar surfaces of chloroplasts are visible. These surfaces are beset with two classes of particles, which have an average diameter of 120 Å and 60 Å; the 120 Å particle are generally composed of 3 to 4 subunits having a diameter of 60 Å.These particles were counted on the thylakoid surfaces, where they are the most numerous.During the light period of the synchronous culture, the total number of particles/₂ on lamellar surfaces remains almost constant: an average of 1500 to 2500 units/₂ was observed.During the dark period, on the other hand, a significative increase of the number of particle/₂ occurs in mother cells 2 hrs. before autospore separation. The average values range from 2000 to 4000 units/₂.It appears that the highest concentrations of 120 and 60 Å particles on the thylakoid surfaces are found in cells in which the photosynthetic O₂ evolution per unit of chlorophyll is minimum (according to the publications of other authors). High concentrations of particles seem to characterize the newly synthesized parts of the thylakoids.     

Premiers stades de l'oogenèse de Rhabdophaga saliciperda (Cecidomyiidae,Diptera)

The females of Rhabdophaga saliciperda have in their somatic cells 8 chromosomes and the males 6. The type of sex determination is therefore: X₁X₁X₂X₂—♀; X₁X₂—♂. The cells of the germinal line have 46 chromosomes, but a variation of their number was observed. In the oogonia and spermatogonia the number of heterochromatic chromosomes may exceed the number of E chromosomes, i.e. 8. In the beginning of the growth stage of the oocytes an incorporation of somatic cells was observed. The nuclei of these somatic cells persist in the cytoplasm of the oocytes until the maturation divisions. The possibility of their participation in the reconstruction of the nucleus of the mature egg is envisaged. The metaphase of the I segmentation division has a complex character. During prophase of the first meiotic division the E chromosomes form 4 bunches of 6–8 chromosomes each. Some univalents may also be present. The 8 S chromosomes form 4 regular bivalents. The 4 groups of E chromosomes persist until metaphase I. During metaphase I a phenomenon of expulsion of the majority of E chromosomes from the metaphase spindle was observed. The 4 bivalents remain in the equatorial plain of the spindle with some E Chromosomes. After this expulsion 2 groups of chromosomes are formed. In connection with them 2 spindles develop. An irregular distribution of E chromosomes follows without their division. The bivalents are probably separated in regular manner. These 2 spindles correspond to the I maturation division. The II maturation division was not observed because of lack of respective stages.