Lower Permian bivalves from central Patagonia, Argentina

The earliest Permian faunal successions of central Patagonia show compositional changes that probably reflected the environmental warming at the end of the Gondwana glaciations. Bivalves of Asselian to probably Early Tastubian age are described. A new genus,Sueroa, is proposed to reunite a previously known species and a new species,Sueroa andreisi n. sp. Another five new species:Parallelodon? quichaurensis n. sp.,Heteropecten cortignasi n. sp.,Etheripecten saraviae n. sp.,Streblopteria montgomeryi n. sp. andPraeundulomya moreli n. sp. are described. Two previously known species:Malimania patagoniensis (González) andEuchondria sabattiniae González are revised and new occurrences are reported. A further eleven species are described, but they are left in open nomenclature being because they are insufficiently known; these are:Phestia? n. sp.,Modiolus sp.,Palaeoneilo sp.,Stutchburia sp.,Schizodus sp.,Vacunella? sp.,Edmondia sp.,Myonia? n. sp.,Myonia? sp. andPachymyonia? n. sp.     

Silurian radiolarians from the Jenolan Caves region,New South Wales,Australia

Moderately-preserved Silurian radiolarians have been recovered from the Jenolan Caves region, eastern NSW, Australia. Radiolarians were first reported from this area in the late 19th Century by T.W. Edgeworth David, but were not described in detail, neither were they illustrated. Nearly 120 years later, the first images of these fossils are presented. The radiolarians reported include: ?Futobari cf. solidus Furutani, ?Zadrappolus sp., Haplentactiniid gen. and sp. indet, Borisella sp., ?Palaeoephippium sp., ?Insolitignum vivanima MacDonald and ?Helenifore speciosus (Furutani). The fauna is similar to others described from Upper Silurian strata in Japan.     

PEP car☐ykinase containing species in the Brachiaria group of the subfamily panicoideae

In the Gramineae, a survey of species among the Brachiaria group of the subfamily Panicoideae, tribe Paniceae revealed that they are PEP car?ykinase containing species. This group includes the genera Brachiaria, Eriochloa and Urochloa. With the exception of the genus Panicum, these are the only genera within the Panicoideae found to contain PEP car?ykinase species. It is suggested that the PEP car?ykinase species of the genus Panicum, P. fasciculatum, P. maximum, P. molle and P. texanum, might be best placed in the Brachiaria group.     

The Antennal Sensilla of Oxelytrum erythrurum (Blanchard) and Oxelytrum apicale (Brullé) (Coleoptera: Silphidae)

The typology and placement of antennal sensilla of the carrion beetles Oxelytrum erythrurum (Blanchard) and Oxelytrum apicalis (Brullé) (Coleoptera: Silphidae) were studied using scanning electron microscopy. Two types of sensilla chaetica, two types of sensilla trichodea, four types of sensilla basiconica, one type of sensilla coeloconica, and an unidentified type of sensillum were found in both species. Sensilla chaetica type 1 are found on the antennomeres proximal to antennal club (A1?CA8); chaetica type 2 are found on the club (A9?CA11). Sensilla trichodea are found on A9?CA11; one type (T1) is found on the proximal portion of the club, the other type (T2) on the apical portion. Basiconica type 1 are found on the dorsal surface of A9?CA11; they are much denser on the apical portion of the antennal club than on the proximal. In O. erythrurum, a nocturnal species of the Chaco-Pampean plain, T2 two are found on A10 and A11. In Oxelytrum apicale, a mountain species, probably diurnal, only A11 bears T2, but they are denser than in the other species. It is suggested that O. apicale depends more on contact chemoreception than O. erythrurum. The ventral surface of the antennal clubs shows no remarkable difference between species.     

Carbohydrates Production and Bio-flocculation Characteristics in Cultures of Arthrospira (Spirulina) platensis: Improvements Through Phosphorus Limitation Process

Carbohydrates are a desirable biomass compound for the generation of several biofuels. Phosphorus nutrient limitation causes a significant increase in the carbohydrate content of the cyanobacterium Arthrospira (Spirulina) platensis. Carbohydrates accumulated up to a content of 63.09?±?3.43?% (±SD) in both batch and semi-continuous cultures. In order the production of carbohydrate-rich biomass through nutrient limitation to be maximized, it is suggested that the limited nutrients have to be supplied in amounts that they on one hand can support the biomass production while on the other hand they alter the composition of the biomass. In this study, phosphorus of 1.82?±?0.16?mg g^?1 of dry biomass was the optimized amount for the maximization of carbohydrates production by A. platensis. Regarding the need to decrease the application amounts of nutrients for biomass production, this study demonstrates that the phosphorus supply could be decreased an order of magnitude with no significant decrease in biomass production. In addition, it was observed that biomass rich in carbohydrates bio-flocculates, during settling without the addition of any flocculation agent or any other intervention. The bio-flocculation efficiency appears to be related with the carbohydrate content of the biomass. In maximum carbohydrate content (60?%), the biomass bio-flocculated at 68.49?±?7.73?% the first 15?min and reached 80.25?±?5.58?% 60?min after settling. The produced carbohydrates might be used as feedstock for biofuel generation, while the bio-flocculation and the overall settling characteristics of the carbohydrate-rich biomass could make its harvesting process much easier.     

Essai de description phénoménologique de l’hallucination

In this paper we would like to expose Sartre’s conception of hallucinations as discussed in his bookL’Imaginaire, published in 1940 and inspired by Edmund Husserl, the founder of phenomenological philosophy at the beginning of the twentieth century.L’Imaginaire concerns the different types of the imagining consciousness, and considers a hallucination as one of them. A hallucination is not therefore like a perception without anything to be perceived, as it is often defined, but belongs to imagination. Such a conception of hallucinations raises different questions, of which, two are: Why do those who suffer from hallucinations think they really do perceive something? How can it be explained that they come to disregard their own imagining activity to the point of believing to perceive what they imagine?     

An immunocytochemical and ultrastructural study of the nervous and muscular systems of Xenoturbella westbladi (Bilateria inc. sed.)

The phylogenetic position of the Xenoturbellida is highly disputed. Are they primitive flatworms? Are they related to Deuterostomia? Do they form a sister taxon to other Bilateria? Are they bivalve molluscs? In order to provide more data for this discussion, a study of the nervous system of Xenoturbella westbladi and its relation to the musculature was performed, using 5-HT and FMRFamide immunocytochemistry, TRITC-conjugated phalloidin fluorescence for staining of F-actin filaments, confocal scanning laser microscopy and transmission electron microscopy. The nervous system comprises solely an intraepidermal net of nerve cells and processes. No ganglia or any other internal nervous structures could be detected. No evidence of 5-HT- or FMRFamide-immunoreactive innervation below the subepidermal membrane complex was obtained. The 5-HT and FMRFamide immunoreactivity occurs in separate sets of neurones. On the ultrastructural level, three types of neurones were observed: (1) the predominating ”light” neurones, (2) the smaller ”dark” neurones and (3) the bipolar sensory neurones bearing a single cilium with a long bipartite rootlet. Non-synaptic, paracrine, release sites are common and synapses are inconspicuous. In the layer of epidermal cells, close to the lateral furrow, F-actin filaments were observed. They reach from the basal membrane to the surface. The organisation of the nervous system appears very simple. Our results are compatible with the hypothesis of Xenoturbellida forming a sister taxon to Bilateria. No evidence was obtained for inclusion of X. westbladi in either the Mollusca or Plathelminthes.     

Deletion of the mating-type sequences in Podospora anserina abolishes mating without affecting vegetative functions and sexual differentiation

The mating-type locus of Podospora anserina controls fusion of sexual cells as well as subsequent stages of development of the fruiting bodies. The two alleles at the locus are defined by specific DNA regions comprising 3.8 kb for mat+ and 4.7 kb for mat?, which have identical flanking sequences. Here we present the characterization of several mutants that have lost mat+-specific sequences. One mutant was obtained fortuitously and the other two were constructed by gene replacement. The mutants are deficient in mating with strains of either mat genotype but are still able to differentiate sexual reproductive structures. The loss of the mating type does not lead to any discernible phenotype during vegetative growth: in particular it does not change the life span of the strain. The mutants can recover mating ability if they are transformed with DNA containing the complete mat+ or mat? information. The transformants behave in crosses as do the reference mat+ or mat? strains, thus indicating that the transgenic mat+ and mat? are fully functional even when they have integrated at ectopic sites.     

Osmotic values of some plant species from Cuba

The authors give measurements of osmotic values in 35 Cuban plant species, using the cryoscopic method. Osmotic values of plants correspond relatively well with environmental conditions, but in different species of the same habitat they may be different. The lowest values were found inCactaceae (?1.6 to ?6.2 atm.) and in epiphyticBromeliaceae (?4.6 to ?4.7 atm.), the highest in halophytes: ?21 to ?56 atm.     

Acquisition/Loss of Modules: the Construction Set of Transposable Elements

Phylogenetic analysis of transposable elements (TEs) allows us to define the relationships between the domains or gene(s) that compose them. Moreover, modules of a few amino-acids can be detected within gag, pol, envgenes or within the integrase domain of retrotransposons and transposase of DNA elements. The combination of these observations clearly shows that the evolutionary history of TEs is the outcome of the acquisition and loss of modules with differing origins and histories. This raises the question of the origin of TEs: are they derived from viruses? Do the basic building bricks come from the prokaryotes, and can they be assembled in the eukaryotes? Are the TEs found in prokaryotes the result of the disintegration of complex elements such as retroelements? Do they evolve from the simplest to the more complex, or are they opportunistic sequences evolving by acquiring and/or losing modules which may be either important or superfluous to their fitness (i.e., their ability to transpose). These are some of the questions that are addressed and discussed in the light of the comparative structures of TEs.     

Supercooling and heterogeneous nucleation of freezing in tissues of tender plants.

The extent to which tissue pieces of several frost tender plant species could be supercooled in the absence of external sources of ice nucleation was determined in a small cold chamber. A considerable range among plant species was revealed in their ability to supercool. This could be expressed as a differential nucleus spectrum that derives the minimum concentration of nucleating sites within the samples. French bean (Phaseolus vulgaris L.) was found to contain nucleators effective in the range ?4 to ?8 °C, whereas spring wheat (Triticum aestivum L.) contained sites active between ?8 and ?16 °C. The data indicate that these plant samples can supercool to temperatures below those normally injurious to them when they are frozen.     

Why are cellular switches Boolean? General conditions for multistable genetic circuits

The logic of cellular decision-making is largely controlled by regulatory circuits defining molecular switches. Such switching elements allow to turn a graded input signal into an all-or-nothing output. Traditional studies have focused on this bistable picture of regulation, but higher-order scenarios involving tristable and tetrastable states are possible too. Are these multiswitches allowed in simple gene regulatory networks? Are they likely to be observed? If not, why not? In this paper we present the examination of this question by means of a simple but powerful geometric approach. We examine the relation between multistability, the degree of multimerization of the regulators and the role of autoloops within a deterministic setting, finding that N-stable circuits are possible, although their likelihood to occur rapidly decays with the order of the switch. Our work indicates that, despite two-component circuits are able to implement multistability, they are optimal for Boolean switches. The evolutionary implications are outlined.     

Bioefficacy of novel cyanobacteria-amended formulations in suppressing damping off disease in tomato seedlings

Biological control of plant pathogens is receiving increasing relevance, as compared to chemical methods, as they are eco-friendly, economical and indirectly improve plant quality and yield attributes. An investigation was undertaken to evaluate the potential of antagonistic cyanobacteria (Anabaena variabilis RPAN59 and A. oscillarioides RPAN69) fortified formulations for suppressing damping off disease in tomato seedlings challenged by the inoculation of a fungal consortium (Pythium debaryanum, Fusarium oxysporum lycopersici, Fusarium moniliforme and Rhizoctonia solani). Treatment with A. variabilis amended formulations recorded significantly higher plant growth parameters, than other treatments, including biological control (Trichoderma formulation) and chemical control (Thiram-Carbendazim). The A. variabilis amended compost-vermiculite and compost formulations exhibited 10?C15?% lower disease severity and 40?C50?% higher values than chemical and biological control treatments in terms of fresh weight and height of the plants. In future, in depth analyses regarding the mechanism involved in biocontrol by cyanobacteria and evaluation of these formulations under field conditions are proposed to be undertaken.     

Extraction protocols for the quantification of phycobilins in aqueous phytoplankton extracts

Phycobiliproteins are light harvesting pigments in cryptophytes, cyanobacteria, and rhodophytes that allow these organisms to absorb light in the green and orange regions of the electromagnetic spectrum. Unlike chlorophylls and carotenoids, however, phycobilins are rarely quantified as part of routine photobiological studies because they require different extraction protocols. The objectives of this study were (1) to compare 10 existing methods to determine that with the highest extraction efficiency and (2) to determine the maximum time limit for the storage of phycobilins before degradation. Cells of the cryptophyte Rhodomonas salina and the cyanobacterium Synechococcus bacillaris were harvested either by centrifugation or filtration and then subjected to lyophilization, mechanical disruption, or freeze?Cthaw techniques. The extraction efficiency for pigments in cells collected on glass fiber filters was always <32?±?5% and thus always significantly lower than in samples harvested by centrifugation, which had extraction efficiencies of 53?±?6?C98?±?11%. Disruption of cells by freezing?Cthawing and sonication both resulted in significantly higher (ANOVA, p?<?0.01) extraction efficiencies than disruption with a tissue grinder. Storage of samples at ?80°C showed no significant pigment degradation over the course of 24 weeks.     

Detection of female plants ofPetasites fragrans and their importance for the determination of the indigenous distribution of the species

Female plants ofPetasites fragrans were detected in material imported from Algeria, and they are now cultivated in Pr?honice. Their importance for the determination of the indigenous distribution of the species was evaluated: all localities in Europe are secondary and only male plants grow there.     

Tissue integrity: hemidesmosomes and resistance to stress.

How do animal tissues resist the shearing forces to which they are exposed during locomotion or harsh encounters with the environment? Genetic analysis in Caenorhabditis elegans is furthering our understanding of the nature and function of the attachments that preserve tissue integrity.     

Adiponectin gene polymorphisms in Egyptian type 2 diabetes mellitus patients with and without diabetic nephropathy

Recently, several reports addressed the associations of adiponectin (ADIPOQ) gene polymorphisms with abnormal adiponectin serum levels, type 2 diabetes mellitus (T2DM), and diabetic nephropathy (DN); however, results are inconsistent. This study aimed to investigate the possible association of ADIPOQ gene polymorphisms with T2DM and/or DN and whether they affect serum adiponectin levels in Egyptian population. Two hundred and ninety-six T2DM patients (100 normoalbuminuric patients, 103 microalbuminuric patients, and 93 macroalbuminuric patients) and 209 controls were enrolled in the present study. Polymorphisms of +45, ?11391, and +276 of the ADIPOQ gene were detected using polymerase chain reaction restriction fragment length polymorphism. Serum adiponectin was measured using ELISA. Our results revealed that ADIPOQ +45 TG and GG genotypes and G allele were significantly associated with T2DM, micro/macroalbuminuria, and decreased serum adiponectin level. ADIPOQ ?11391 AA genotype frequency was significantly increased in T2DM group. Moreover, GA and AA genotypes and A allele of ADIPOQ ?11391 were significantly associated with susceptibility to macroalbuminuria despite increased serum adiponectin concentrations. While, ADIPOQ +276 TT genotype and T allele were protective factors regarding the susceptibility to T2DM and micro/macroalbuminuria, and they were significantly associated with increased adiponectin levels. We observed also that the decrease of the serum Adiponectin level was accompanied by an insulin resistance, albuminuria, as well as an increase of serum creatinine. We concluded that ADIPOQ +45; ADIPOQ ?11391 gene polymorphisms are associated with T2DM and/or DN in Egyptian population. While, ADIPOQ +276 gene polymorphism is a protective factor regarding T2DM and/or DN susceptibility.     

Estimating weight�Clength relationships without individual weight data: an application to the American lobster (Homarus americanus) fishery of Long Island Sound

The estimation of weight?Clength relationship of fish species requires having data on individual weight and length. However, individual weight data are often not available because they are too expensive or not feasible to gather and the relationship cannot be explicitly estimated. Yet, in this paper I develop a simple methodology that allows me to estimate a weight?Clength relationship when only aggregate weight data are available. To show its usefulness, the methodology is applied to the American lobster (Homarus americanus) population of Long Island Sound. Results indicate the existence of isometric growth for American lobsters in this geographical location: W = 0.000924L ^2.9619. The estimated relationship is used to predict individual weight of lobsters which are then used to construct biomass indexes for three size classes of lobsters for the time period 1987?C2006. This analysis suggests that is not necessary to invest efforts in collecting individual weight data to be able to construct meaningful indicators of fish population.     

Study of NAT2 genetic polymorphism in West African subjects: example of an healthy non-smoker Senegalese population

The NAT2 genetic polymorphism determines the individual acetylator status and, consequently, the capacity to metabolize, or not, drugs and xenobiotics which are substrates of NAT2. As the nature and frequency of the NAT2 polymorphisms vary remarkably between populations of different ethnic origins, genotyping strategies used to predict the acetylation phenotype need to be adapted for each particular population regarding their genetic backgrounds at this locus. As few data on the genetic polymorphism of NAT2 are available in the Senegalese population, we performed an extensive identification of NAT2 variants in 105 healthy non-smoker Senegalese subjects by direct PCR sequencing of the coding region. Eleven previously described SNPs were identified in this Senegalese population. Upon allele analysis, the four most frequent alleles were of the NAT2*5- (35.7?%), NAT2*6- (21.0?%), NAT2*12- (16.7?%) and NAT2*14- (10.0?%) type, the remaining alleles, including the wild-type NAT2*4, having each a frequency lower than 10?%. According to the observed genotypes, 51 and 50 subjects were predicted to be of the rapid (48.6?%) and slow (47.6?%) acetylator phenotype, respectively, while four individuals (3.8?%) were considered of unknown phenotype as they carry at least one allele with a yet unknown functional effect. These baseline data would be of particular interest to set up an efficient genotyping strategy to predict the acetylation status of Senegalese patients with tuberculosis and, thus, to optimize their isoniazid treatment.