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Showing papers by "Spanish National Research Council published in 1969"


Journal ArticleDOI
TL;DR: The equations have been used to predict the distribution of dendritic spines corresponding to age-groups of mice not previously studied and to find out the age of mice from the data of their known spine distribution resolving the inverse equations of IF (T) and B(T).
Abstract: A set of equations which define the distribution of spines along the apical dendrites have been developed. They are satisfied by the distribution of spines and its evolution with the age in the apicals of the layer V pyramidal cells of the visual cortex in normal and dark raised mice. The principal equation describes the distribution of the spines with three coefficients IF, B and K whose values have a functional relation with the age T of the animal. This relation has been defined by three additional equations whose coefficients were calculated. The equations have been used to predict the distribution of dendritic spines corresponding to age-groups of mice not previously studied and to find out the age of mice from the data of their known spine distribution resolving the inverse equations of IF (T) and B(T).

135 citations


Journal ArticleDOI
TL;DR: A quantitative model of the metabolic crossroads of D-glyceraldehyde has been developed that permits a prediction of the relative contributions of the phosphorylative, oxidative and reductive pathways in different conditions.
Abstract: quantitative model of the metabolic crossroads of D-glyceraldehyde has been developed. This model permits a prediction of the relative contributions of the phosphorylative, oxidative and reductive pathways in different conditions. The main pathway for D-glyceraldehyde metab- olism in liver is phosphorylation by triokinase. Many investigations have been directed to look for the pathway(s) of incorporation of fructose into the common glycolytic pathway.

110 citations


Journal ArticleDOI
TL;DR: The results of a nutritional approach involving diets rich in fructose and/or showed that pyruvate carboxykinase levels were high, consistent with the hypothesis of induction by insulin of the enzymes that catalyze these two irreversible steps of glycolysis in liver.
Abstract: pyruvate carboxykinase were low. A metabolic bifurcation to glycolysis and gluconeogenesis, below and above the trioscphosphates level respectively, has then been shown to be easily maintained in liver. It is suggested that the induction of glucokinase and pyruvate kinase in diabetic animals after insulin administration is a sequential process that involves hormonal induction of glucokinase by insulin and secondary metabolite induction of the L isoenzyme of pyruvate kinase by some glycolytic intermediate. The occurrence of independent mechanisms for the regulation in liver of the activity of enzymes which catalyze irreversible steps of glycolysis and gluconeogenesis affords a valuable metabolic plasticity. Changes in the apparent concentration of a number of enzymes in liver have been observed in relation to the nutritional and hormonal conditions of the animal. Some of these changes could be of considerable significance in the regulation of major metabolic pathways. Glucose-6-phosphatase [l], fructosediphosphatase [a], phosphoenolpyruvate carboxykinase [3] and pyruvate carboxylase [4] had been reported to be increased in gluconeogenic conditions, like fasting, diabetes, or corticosteroids administration. In 1963, an insulin-dependent glucokinase was identified [5-71. After the finding of the induction of glucokinase in rat liver by insulin, Weber et al. [S] postulated the hypothesis that the key steps of glycolysis and gluconeogenesis could depend on two functional genic units, with insulin as inducer of the glycolytic unit and repressor of the gluconeogenic one. Shortly afterwards a number of observations were reported on the behaviour of pyruvate kinase [9- 111 and phosphofructokinase [12], consistent with the hypothesis of induction by insulin of the enzymes that catalyze these two irreversible steps of glycolysis in liver. This paper presents the results of a nutritional approach involving diets rich in fructose and/or

69 citations


Journal ArticleDOI
TL;DR: In this article, dual ac Hall effect measurements of the chemisorption of oxygen on gallium-doped zinc oxide have shown that oxygen is mainly O 2 − between 100 ° and about 180 °C, and as O − above about 230 °C.

65 citations



Journal ArticleDOI
TL;DR: A high glucose diet fed ad libitum decreased the activities in rat liver of histidase, serine dehydratase, homoserine dehydRatase, ornithinetransaminase, mitochondrial aspartate transaminase and cytoplasmic alanine transaminases, as compared to normal fed animals.
Abstract: A high glucose diet fed ad libitum decreased the activities in rat liver of histidase, serine dehydratase, homoserine dehydratase, ornithine transaminase, mitochondrial aspartate transaminase and cytoplasmic alanine transaminase, as compared to normal fed animals. Casein hydrolysate or tryptophan alone given to protein deplted rats increased the hepatic levels of serine dehydratase, alanine transaminase and tyrosine transaminase. Histidase and homoserine dehydratase were increased by casein hydrolysate but not by tryptophan. Aspartate transaminase was increased by tryptophan, but not by casein hydrolysate. Glucose administered intragastrically partly or totally counteracted the induction of serine dehydratase, tyrosine transaminase, cytoplasmic alanine transaminase by cortisol of glucagon administration to protein depleted rats. The similar induction of ornithine transaminase and cytoplasmic aspartate transaminase by cortisol was also counteracted by glucose.

46 citations


Journal ArticleDOI
TL;DR: Test the hypothesis that the glucokinase, being an enzyme apparently unique to the liver, would be restricted to the parenchymal cells of this organ, while the common hexokinase found in homogenates could be contributed, at least mainly, by the mesenchymatous tissue, and results indicate that indeed these two enzymes have essentially different cellular location in liver.

39 citations



Journal ArticleDOI
TL;DR: In contrast to amphi-AtlanticGammarus faunas of northern glaciated coastlines, the Gammarus species of the Middle Atlantic States are North American endemic.
Abstract: Gammarus daiberi n. sp. andGammarus palustris n. sp. are newly described from estuaries of the Chesapeake and Delaware Bay regions, and further tide-water records ofGammarus tigrinus Sexton,G. fasciatus Say, andG. mucronatus Say are given. A key to American Atlantic species ofGammarus (sens. lat.) is included. In contrast to amphi-AtlanticGammarus faunas of northern glaciated coastlines, theGammarus species of the Middle Atlantic States are North American endemic.

31 citations


Journal ArticleDOI
01 Jan 1969
TL;DR: In practice, palladium is acted upon by water only at high temperatures [2] and it does not tarnish when exposed to moist air, and at ordinary temperatures this metal is not attacked by nonoxidizing acidic solutions as mentioned in this paper.
Abstract: As the theoretical corrosion (potential-pH) diagram shows, palladium metal is thermodynamically stable at all pH's in the presence of aqueous solutions free from strong oxidizing, reducing, or com-plexing agents [1]. In practice, palladium is acted upon by water only at high temperatures [2] and it does not tarnish when exposed to moist air. Moreover, at ordinary temperatures this metal is not attacked by nonoxidizing acidic solutions.

24 citations


Journal ArticleDOI
TL;DR: El efecto de la macroalga Caulerpa sertular ;oides sobre el crecimiento, sobrevivencia y produccion en cautiverio del carnaron cafe Penaeus a temperaturas invernales se estudio en La Paz, Bolivia.
Abstract: The effect of the macroalga Caulerpa sertularioides on the growth, survival and yield of captive yellowleg shrimp Penaeus californiensis (Holmes, 1900) at winter temperatures (14 to 21°C) was studied at La Paz, B.C.S., Mexico. Nine experimental units (three per treatment) c()nsisting in 150 l-fiberglass tanks were used; Shrimp growth with macroalgal presence was 3.98 ± 0.4 gafter 10 weeks, survival was 100% and yield 36.24 ± 4.3 g. These results were better than those obtained with indirect presence, and absence of the macroalga, which were not different among themselves. Under indirect rnacroalgal presence growth. survival and yield were 0.73 ± 0.4 g, 75± 10% and 7.8 ± 1.2 g. Without macroalgae, corresponding values were 0.46 ± 0.4 g, 68.7 ± 12% and 5.6 ±1.1 g. Significailt differences were found between "absence" a1id "indirect presence".The macroalgae possitively affect the development of tpis shrimp in captivity

Journal ArticleDOI
TL;DR: Several v-triazoles were synthesized by 1,3-dipolar cycloaddition of certain α-azido ethers and α -azidothioethers to phenylacetylene.

Journal ArticleDOI
01 May 1969-Nature
TL;DR: For example, during two successive cruises to the Pamunkey River in autumn 1968, hydromedusae of the family Olindiidae, never before found in Virginia, were collected in trawls.
Abstract: THE Virginia Institute of Marine Science has recently been studying the biota of waters of low salinity in several Chesapeake Bay tributaries. During two successive cruises to the Pamunkey River in autumn 1968, hydromedusae of the family Olindiidae, never before found in Virginia, were collected in trawls. The specimens were identified as Maeotias inexpectata, a brackish water species originally described from the Don and Kuban estuaries, Sea of Azov1, and known elsewhere only from the Black Sea2. Ten specimens were collected on October 15, 1968, at station P–40 (37° 33′ N, 76° 53′ W, 4.2‰ salinity, 20.1° C water temperature) and one specimen was found on November 14, 1968, at station P–30 (37° 33′ N, 76° 50′ W, 10.7‰ salinity, 11.3° C water temperature. Hydrographic conditions at these two stations vary considerably at different tidal stages as well as seasonally, but salinities are mesohaline or lower at all times. Over a 13 year period, 1955–1967, the mean salinity and temperature during autumn were 9.0‰ and 12.5° C at station P–30, 1.2‰ and 12.2° C at station P–40 (W. A. Van Engel, personal communication).

Journal ArticleDOI
TL;DR: In this article, the helical content of poly(γ-benzyl-L-glutamate) was calculated using the transition from experimental data and its interpretation, and the parameter ΔH obtained was in good agreement with the calorimetric one and v was found to be independent of temperature and solvent.
Abstract: In this paper two points are considered: the methods of evaluating the helical content θ and the calculation of the parameters of the transition from experimental data and its interpretation. The parameter ΔH obtained is in good agreement with the calorimetric one and v is found to be independent of temperature and solvent and in agreement with the ordinarily accepted value for poly(γ-benzyl-L-glutamate). The different methods of estimating θ are discussed for both polypeptides.

Journal ArticleDOI
TL;DR: Results showed that a rapid, normal fermentation always occurred when the proper lye was used, and only in the case of an inappropriate alkaline treatment could pasteurization help the growth of lactobacilli.
Abstract: The effect of lye concentration and pasteurization on the fermentation of Spanish-style Manzanilla green olives was investigated Results showed that a rapid, normal fermentation always occurred when the proper lye was used, and only in the case of an inappropriate alkaline treatment could pasteurization help the growth of lactobacilli Although pasteurization does not seem to affect color of processed olives, texture tests gave lower values for pasteurized samples than for those obtained from nonpasteurized olives

Journal ArticleDOI
01 Jan 1969
TL;DR: A public appeal for closer cooperation between physicists and chemists on the problems raised by chemisorption and catalysis on solid surfaces was made more than 10 years ago.
Abstract: One of the eminent contributors to the field reviewed here launched, more than 10 years ago [1], a public appeal for closer cooperation between physicists and chemists on the problems raised by chemisorption and catalysis on solid surfaces. Enriched by many stimulating remarks, pointing to various directions of surface research, this appeal deserved more success; but solid state physicists, by and large, have been much too busy with clear-cut problems of their own. Besides, it is only very recently that semiconductor surface physics [2] has come of age.

Journal ArticleDOI
TL;DR: Hemidactylus frenatus Schlegel is a nocturnal lizard widely distributed in Southern Asia, the Pacific Islands, tropical Africa, Australia and Polynesia.
Abstract: Hemidactylus frenatus Schlegel is a nocturnal lizard widely distributed in Southern Asia, the Pacific Islands, tropical Africa, Australia and Polynesia (Smith and Taylor 1950, Bustard 1970).



Journal ArticleDOI
TL;DR: In this article, die Ultrastruktur von intranuclearen stabformigen Gebilden bei einem Oligodendrogliom beschrieben.
Abstract: Es wird die Ultrastruktur von intranuclearen stabformigen Gebilden bei einem Oligodendrogliom beschrieben.

Journal ArticleDOI
TL;DR: In this article, the structures of these substances are discussed on the basis of their chemical and spectroscopic properties, and they are shown to react with β-diketones and with benzoylacetaldehyde yielding N-glycosyl derivatives of β-amino α, β-unsaturated ketones.

Journal ArticleDOI
TL;DR: In this article, the activity of 4 soil enzymes in farms under different agronomic managements and in different soil types was analyzed The enzymes tested were phosphatase, β-glucosidase, dehydrogenase, and urease.
Abstract: The activity of 4 soil enzymes in farms under different agronomic managements and in different soil types was analyzed The enzymes tested were phosphatase, β-glucosidase, dehydrogenase and urease Soil samples were taken from the first 20 cm in depth, in order to determine the activity of the 4 enzymes and analyze them chemically It was found that Dehydrogenase enzyme activity ranged from 013 to 446 with an average of 117 (μg INTFg - 1 h -1 ); β-glucosidase enzyme ranged from 319 to 2081 with an average of 1081 (μg PNPg -1 h -1 ) Furthermore, phosphatase had values between 4134 and 30436 with an average of 15215 μg PNPg -1 h -1 , while Urease ranged from 125 to 528 with an average of 383 μg N-NH4g -1 h -1 Phosphatase correlated with the percentage of organic matter and carbon in the soil (075 and 076 respectively, p<001); an inverse relationship was found between the activity of this enzyme and the content of available P (-053r, significant at p<010) Urease correlated with phosphatase (r=061 p<005) and with dehydrogenase (r-077 p<001) Multivariate cluster analysis based on the enzymatic activity allowed to make similar groups according to the type of crop, which shows the potential of usage that this property has for undertaking more detailed studies

Journal ArticleDOI
01 Jan 1969
TL;DR: In this article, an infrared study of the short side branching content of a series of commercial low molecular weight polyethylenes crystallized from diluted solution was carried out and the determination of methyl group concentration was based on the band at 1380 cm−1.
Abstract: The present work is concerned with an infrared study of the short side branching content of a series of commercial low molecular weight polyethylenes crystallized from diluted solution. The determination of methyl group concentration was based on the band at 1380 cm−1. Attention was paid to the crystal perfection which is influenced by the branching concentration, by reference to the doublet at 1460 cm−1. Finally reference is made to the depression of crystal melting point which has been found to be influenced mainly by the number of the side branches as well as by the length of the main chains.

Journal ArticleDOI
TL;DR: It is hypothesized that sympatric coexistence of atherinopsids in Lago de Patzcuaro is explained by food resource availability and ontogenetic variation in their diets, and highlights the importance of analyzing ecological patterns and mechanisms as basic elements for designing conservation strategies of species flocks, especially under habitat loss and introduction of exotic species.
Abstract: Since Barbour proposed sympatric speciation to explain evolution of silversides in the Lerma-Santiago basin, relatively little subsequent study has been done. We assessed foraging patterns of four sympatric silversides species ( Chirostoma estor , Chirostoma grandocule , Chirostoma attenuatum and Chirostoma patzcuaro ) in Lago de Patzcuaro to understand resource partitioning and their sympatric coexistence. We assessed the abundance of invertebrate prey in three feeding habitats and measured physical and chemical habitat parameters at two study sites. Fish were collected during the wet (September 1987) and dry (March 1988) seasons; a total of 242 gut contents were analyzed. We evaluated the trophic guild of each species using the index of relative importance (IRI), prey selectivity with the Ivlev Electivity Index (E), dietary diversity using Shannon and Wiener diversity index (H’), and diet overlap using Morisita index. All silverside species were determined to be predacious carnivores that feed mainly on nekton and periphyton. Dietary diversity and prey selectivity patterns were similar among species and diet overlap was >70%. Our data do not support the proposition that coexistence of these four fish species is maintained by dietary specialization. We hypothesize that sympatric coexistence of atherinopsids in Lago de Patzcuaro is explained by food resource availability and ontogenetic variation in their diets. This study highlights the importance of analyzing ecological patterns and mechanisms as basic elements for designing conservation strategies of species flocks, especially under habitat loss and introduction of exotic species. Conservation efforts are urgent to preserve the rare evolutionary process of sympatric speciation (habitat segregation) that is occurring in other lakes in central Mexico, and probably already lost in the Lago de Patzcuaro, as a result of poor management and inadequate conservation strategies. KEY WORDS: Atherinopsidae, feeding interactions, species flocks, evolutionary process, conservation.

Journal ArticleDOI
TL;DR: This paper proposes to study the component elements of the intracerebral vessel wall and to see what analogies the authors can find in them with those of the leptomeninx itself, which has already been considered.
Abstract: Palgrem,5 Rio-Hortega in 1916 and Achucarro7 in 1911 in the matter of silver impregnations. We also spoke of the advantages of each new method when, besides their usefulness in themselves, they enable us to make a new approach to other subjects such as the constitution of the leptomeninx and of the cerebral vessels. In this paper we propose to study the component elements of the intracerebral vessel wall and to see what analogies we can find in them with those of the leptomeninx itself, which we have already considered We will not repeat here the reasons we expounded, or the bibliographic details we gave from References 8 through 76 in the previous paper,1 but in later comments on the findings reported in this paper we will refer to the bibliography and figures of the last study of the leptomeninx when necessary.

Journal ArticleDOI
TL;DR: In this article, a method for the measurement of circular diohroism through different directions in uniaxial crystals is proposed based on the knowledge of two straightforward experimental magnitudes: the circular dichroism of the slab through the optical axis and its powder.

Journal ArticleDOI
TL;DR: Se estudia el periodo reproductivo del camaron de roca Sicyonia penicillata en el area of Bahia Kino, Sonora y postula the idea of un posible patron de migracion de juveniles hacia areas someras de Bahi Kino.
Abstract: Se estudia el periodo reproductivo del camaron de roca Sicyonia penicillata en el area de Bahia Kino, Sonora, de enero a diciembre de 1996 mediante muestreos quincenales efectuados a bordo de embarcaciones de la flota camaronera comercial y un crucero de investigacion durante julio. La actividad reproductiva de la especie inicia a partir de los 25 mm de longitud abdominal, pero la talla de madurez sexual masiva de la especie se ubico en 55 mm de longitud abdominal. Se encontraron organismos maduros todo el ano, pero el patron de reclutamiento indica que existe un periodo reproductivo masivo de agosto a enero; un segundo periodo, menos intenso ocurre en marzo y abril. Estos resultados son coincidentes para los meses en los que se cuenta con datos de madurez gonadica. Se postula la idea de un posible patron de migracion de juveniles hacia areas someras de Bahia Kino.

Journal ArticleDOI
TL;DR: In this paper, from the reaction of benzotriazoles with 2,3-dihydro-4H-pyrane and 2,acetoxymethyl-3,4-dioxymethyl2-tetrahydropyranyl (2-TTRY) compounds, the corresponding 1-(2-to-TTHRY) and cis-and trans-1-(6-acetoxyl-methyl-2-treeyranyl) derivatives were obtained.


Journal ArticleDOI
TL;DR: Antimony electrodeposition from the molten Na2S-Sb2S3 system has been studied in the 800-1000°C temperature range as a function of temp.