Early evidence of Prunus and Prunus cf. amygdalus from Palaeolithic sites in the Khorramabad Valley,western Iran

Along with the early age obtained for the cultural remains attributed to anatomically modern humans from Kaldar Cave, the archaeological assemblages recovered from both Kaldar and Gilvaran Cave located in the Khorramabad Valley (Iran), have yielded charcoal remains that allow the identification of Prunus spp. These remains correspond to the Middle and Upper Palaeolithic, which are the earliest finds attesting to the presence of this taxa in the area. Our anatomical observation of the samples revealed the presence of Prunus spp. (plums) and Prunus cf. amygdalus (cf. almond). This also reflects specific plant communities in the area, characteristic of open forest growing in cool, dry conditions. These results provide new insights into the arboreal cover in this area during an Upper Pleistocene period. Furthermore, anthracological evidence together with other contextual materials provides new clues to assess how Neanderthals and early modern humans adapted to their surrounding landscape, and their relationship with their environment in this region and beyond.     

Dehydrogenases reducing NAD+ in the presence of D (-) 3- phosphoglycerate in mycobacteria (BCG, H37Ra, M. phlei)]

Referring to the elution volume on a Sephadex G-150 column only one specific peak is obtained, the same for the BCG, H37Ra and Mycobacterium phlei strains grown on Sauton synthetic medium. Some properties of these partially purified dehydrogenases are studied (conservation and dialysis in media of different salt concentrations, equilibrium constant, Km, heat stability). All enzyme preparations from tubercle bacilli (BCG, H37Ra) are readily inactivated by heat and are very unstable in solutions of low ionic strength. In contrast, under the same experimental conditions, all enzyme samples from M. phlei are, comparatively, much more stable towards these factors [heat, salt (potassium phosphate, NaCl) concentration].     

Ostracodes from the Early Cenomanian of Jordan.A preliminary report

Ostracode faunas have been identified for the firsttime in Early marine Cenomanian sediments of the Ajlun Group (Jordan) outcropping East of the Jordan Rift Valley. The faunal assemblages contain 14 genera and 17 species. Sediments indicate the internal part of a carbonate platform. The Ostracodes are closely related to those of neighbouring regions; accordingly, in the Tethyan context, Jordan belongs to the North Africa — Middle East bioprovince.     

Truyolsodontos estauni n. gen., n. sp., Truyolsodontidae,a new family of lamniform sharks from the Cenomanian of northern Spain

Truyolsodontos estauni n. gen., n. sp. is described based on fossil teeth from the middle and upper Cenomanian of northern Spain. The species Protoscyliorhinus magnusLandemaine, 1991 is withdrawn from the genus Protoscyliorhinus and placed in this new one. For the new genus, the new family Truyolsodontidae is proposed.     

Quaternary structure and proteolysis of the polynucleotide phosphorylase from C. perfringens]

This report describes structural studies on purified polynucleotide phosphorylase from C. perfringens. A method is described for the purification of the enzyme which yields a product equivalent in activity to the native polynucleotide phosphorylase from E. coli. These studies revealed a molecular heterogeneity arising from successive stages of proteolysis, to which this enzyme is especially sensitive; unusally, the enzyme is obtained as a mixture of variable proportions of the native and proteolysed forms. We found in all cases a trimeric basic structure composed of the native (alpha) or proteolysed (lapha) or proteolysed (alpha', alpha") catalytic sub-units, However, the enzyme is rather easily dissociated into its sub-units, a phenomenon which seems to accompany proteolysis (Table). Under the action of either endogenous proteases or trypsin, two enzymatic forms are obtained: their quaternary structures seem analogous, but they differ in their catalytic properties from each other and from the initial enzyme. With some care at each step of purification, the polynucleotide phosphorylase of E. coli can be obtained exclusively in its native form. The greater susceptibility to proteolysis of the enzyme from C. perfrigens and the relationship between such degradation and quaternary structure seem to be at the origin of the peculiar behavior of this polynucleotide phosphorylase.     

Woody macroremains from the Acheulian site of Torralba: Occurrence and palaeoecology of Pinus cf. sylvestris in the Middle Pleistocene of the Iberian Peninsula

The pieces of wood extracted by the Marquis of Cerralbo at the Acheulian site of Torralba constitute one of the few materials from this famous locality that have not been subjected to detailed study by researchers. Over a century after their extraction, the present paper provides the first anatomical results of these 34 woody remains. The results highlight the presence of the taxon Pinus sylvestris–nigra group (Pinus cf. sylvestris) at the site, thus constituting one of the few and oldest references attributable to the aforementioned taxon for the Iberian Peninsula. The anatomical diagnosis confirms the existence of Middle Pleistocene landscapes with pine woods at elevations at least 200 m lower than at present in the site area. From a taphonomic point of view, the wood samples exhibit the typical morphologies of woody macroremains preserved in continental sedimentary environments, and there was no evidence at all that they had previously been manipulated by man.     

AFLP analysis of the genetic diversity of Meloidogyne chitwoodi and M. fallax, major agricultural pests

M. chitwoodi and M. fallax populations are clustered and separated from the other species studied. The genetic diversity observed for M. incognita, M. arenaria, M. javanica, M. hapla, and M. mayaguensis correlates well with the previously validated species. Two main groups can be identified within the M. chitwoodi/M. fallax cluster, the first group comprises only M. chitwoodi populations whereas the second group is made of M. chitwoodi and M. fallax populations. Moreover, M. chitwoodi displays a higher genetic diversity than M. fallax and is characterised by the presence of several clusters.     

Evaluation of the resistance to two nematodes: Radopholus similis and Meloidogyne spp. in four banana genotypes in Morocco

Radopholus similis and Meloidogyne spp. are the main nematode parasites of banana plants grown under plastic shelters in Morocco. A test was made in pots to evaluate the resistance of four genotypes of banana to these nematodes. Infection by Meloidogyne spp. brought about an increase in root weight in all banana plants tested because of gall formation. The inoculation of R. similis produced a reduction in length and diameter of the pseudo-trunk as well as in root and aerial mass in all genotypes. Pisang jari buaya showed the significantly lowest number of Meloidogyne nematodes per 10 g of roots, whereas for R. similis, the significantly smallest numbers were obtained in Pisang berlin and Pisang jari buaya. Therefore, Pisang jari buaya was the only banana genotype studied to show some degree of resistance to both nematodes.     

New advances on the Aurignacian in the central Iberian Mediterranean basin

This study aims to obtain a chronological and cultural framework of the Evolved Aurignacian in the central Iberian Mediterranean basin and find agreement between this framework and other sequences of the Iberian southeast. Over the last few years, there has been remarkable progress in the research of the Evolved Aurignacian sites in the Valencian area, making a review of the main characteristics of the technocomplex on a regional scale necessary. The recent fieldwork carried out in Cova de les Malladetes (Valencia) and in Cova de les Cendres (Alicante) have been key to understanding the lithic, osseous and ornament assemblages ascribed to the Evolved Aurignacian. Several Bayesian modelled ages have been constructed from the large dataset of chronological dates obtained at Malladetes and Cendres, as well as in other sites. The Bayesian models have allowed us to chronologically place the characteristics of the analysed assemblages. The present research supports the importance of the Aurignacian as the first technocomplex of the Upper Palaeolithic in this area of the Iberian Peninsula.     

Reconsidering the Early Neolithic of Anatolia. Recent recoveries,some excerpts and generalities

In the course of last decades Neolithic research has taken a new pace in Turkey, while projects in the western and the central parts of the of the country have been working mainly on the later stages of the Neolithic era, those in south-eastern Turkey had their focus on the incipient stages of neolithization. Work in the south-eastern parts, highlighted by the results attained at Göbeklitepe has been carrying out large scale excavations at several Pre-Pottery Neolithic sites, most of them having their earliest layers by the very beginning of PPNA, evidence of antecedent stages being highly debatable. Recent recoveries have been greatly elaborating our understanding on the entire span of Neolithic way of living, also displaying the differences among distinct core areas of neolithization. However, more significant is the outcome of new research taking place in the Upper Euphrates-Upper Tigris basins of south-eastern Anatolia, revealing ground breaking results so different from our conventional perceptions that redefining what is implied by the term Neolithic is now stands as an absolute necessity; inevitably some more time is necessary for the newly emerging picture on Neolithic process to sink in. However, some of the recent findings being unexpectedly different is apt to lead to speculative misconceptions, particularly when coupled with deeply rooted biases of research history. In this respect, the paper will present a conspectus on the progressive stages of Neolithic research in Anatolia, touching upon some biases in retrospect. Accordingly, the paper neither intends to cover an exclusive narrative of research history nor to bring the highlights of present research; it is targeted to surface the modalities that patterned past research so as a provide a subtle bases to future prospects.     

Metabolism of cholesterol in normal hamster fibroblasts and those transformed by the SV 40 virus. Effect of low density lipoproteins

The amount of cholesterol and the percentage of esterified cholesterol were increased in transformed cells. The cholesterol synthesis from [14C] sodium acetate was reduced and cholesteryl oleate uptake increased by 3 fold in transformed cells. The activity of acyl coenzyme A-cholesterol-acyltransferase, measured in situ was also increased in transformed cells. Studies with 125I-LDL pointed out an increase of binding, and especially of internalization of LDL by transformed cells. Finally, long term culture in a lipoprotein-deficient medium showed that transformed cells exhibited a higher ability (tested by growth rate and cholesterol synthesis) to adapt themselves to lipid depletion.     

Sunflower seed protein: size and charge heterogeneity in subunits of the globulin fraction

The subunit heterogeneity of the globulin fraction of sunflower seeds was investigated by two dimensional electrophoresis, using isoelectric focusing in the first dimension and sodium dodecyl sulphate polyacrylamide gel electrophoresis in the second dimension. Under non reducing conditions, intermediary subunits B, C and D (molecular weight 54 000, 48 000 and 40 000, respectively) were focused within a pI range 5.4-6.0 but intermediary subunits A (molecular weight 60 000) focused within a pI range 6.3-6.8. Under reducing conditions the electrophoretic patterns show that intermediary subunits consist in large "acidic" and small "basic" subunits linked by disulphide bonds. The large subunits of B species are more acidic and less heterogeneous than the corresponding subunits of the A species. These results confirm that helianthinin had a "legumin-type" structure.     

Kinetic cooperativity in the concerted model for allosteric enzymes.

The cooperativity of enzyme-substrate interactions is investigated in the concerted allosteric model of Monod, Wyman and Changeux. The general case of K-V systems is considered, in which the two protomer conformational states R and T postulated in the theory differ in catalytic and binding properties. An expression for the Hill coefficient nH defined with respect to the asymptotic velocity V infinity to is analyzed in conditions which exclude substrate inhibition. Kinetic cooperativity is always positive (nH greater than 1) in the case of a dimer enzyme, and in the case of an inactive T state. Slight kinetic negative cooperativity (nH less than 1) occurs under restrictive conditions for larger numbers of protomers when the substrate binds significantly to the less active state of the enzyme, but the phenomenon remains negligible for trimers and tetramers. These conclusions differ from those obtained [A. Goldbeter, J. Mol.Biol.90 (1974) 185] with the Hill coefficient based on the absolute maximum velocity, which may exceed the experimental value V infinity to in K-V systems. The results extend those of Paulus and DeRiel [J. Mol. Biol. 97 (1975) 667] and support the view that in most cases, negative cooperativity is not compatible with a mechanism based on a concerted and conservative allosteric transition. The Hill coefficients for binding and catalysis are compared in K-V systems.     

Populus nigra L. in the Garonne valley: legacy of the past and present constraints

This study used documents from archives and historical maps to follow the simultaneous change of the riparian woodlands (where Populus nigra is dominant) and the poplar plantations. Results showed that the riparian woodland decreased by 81% over the two last centuries. Each period was characterised by the dominance of only a few number of clones. The risk of introgression due to the massive presence of such a restricted genetic material around P. nigra was discussed. The impact of river management on poplar regeneration was examined as well.     

Reversibility of the effects of cadmium on the growth and nitrogen metabolism in the tomato(Lycopersicon esculentum)

In order to better understand the effects of heavy metals on the growth of plants, we decided to perform recovering experiments by following both chemical and physiological parameters in cadmium pre-stressed tomato seedlings after cadmium had been removed from the nutrient solution. The work shows that cadmium suppression results in resumption of growth activity. The biomass of leaves and stems rose steadily. The increase in root biomass exceeded those of leaves and stems. At the same time, nitrate content was increased to reach the level obtained with unstressed controls. In all the organs studied, the activities of the enzymes involved in the anabolic nitrogen primary assimilation pathways (nitrate reductase (NR), nitrite reductase (NiR) and glutamine synthetase (GS) soared after that cadmium had been removed. While NAD(+)-dependent glutamate dehydrogenase (GDH-NAD+) activity also rose progressively during the recovering time, the cognate NADH-dependent glutamate dehydrogenase (GDH-NADH) activity decreased. This result allows us to propose that the ammonia produced by the stress-induced protein catabolism is detoxified and re-assimilated by the GDH-NADH isoenzyme. On the basis of these results, we will discuss the ability of the plant to dilute the effects of pollutants during the recovering period. An important outcome of this work is that a transient contamination of the culture medium by pollutants is not necessarily followed by a significant depreciation in product yield or quality.