scholarly journals Avaliação da estabilidade de agregados e a vulnerabilidade à erosão ao longo de uma vertente no município de Araruna, região noroeste do Paraná-Brasil / Evaluation of aggregates stability and vulnerability to erosion along a shed in the municipality of Araruna, northwest region of Paraná-Brazil

2018 ◽  
Vol 28 (55) ◽  
pp. 845-862
Author(s):  
Fabiana Barros Medeiros ◽  
Francieli Sant'ana Marcatto ◽  
Hélio Silveira ◽  
MariaTeresa De Nóbrega
Keyword(s):  
Structural Analysis ◽  
Soil Cover ◽  
Morphological Characteristics ◽  
Soil Horizons ◽  
Water Flows ◽  
Sandstone Formation ◽  
The Stability ◽  
Northwest Region

Esta pesquisa tem como objetivo estudar a vulnerabilidade à erosão dos solos da zona de contato do arenito da Formação Caiuá com o basalto da Formação Serra Geral, no município de Araruna, Mesorregião Noroeste Paranaense, dando enfoque ao papel da estabilidade da estrutura atual dos solos, considerando-se as alterações produzidas pelas formas de uso e ocupação da área. A análise realizada também considerou as variações das características morfológicas dos solos em perfil e ao longo da litossequência (sistema pedológico), assim como os seus reflexos na geração de setores mais ou menos suscetíveis à erosão na vertente. Para o levantamento dos solos ao longo da vertente foram utilizados os procediments propostos pela Análise Estrutural da Cobertura Pedológica e a coleta de amostras para a determinação da granulometria e estabilidade de agregados. Os resultados indicaram a ação dos fluxos de água laterais e verticais, atuando na transformação dos horizontes dos solos ao longo da vertente e uma variação da estabilidade estrutural associada as características morfológicas dos solos e ao tipo de uso e manejo empregado. Os Argissolos apresentaram agregados pequenos e um gradiente textural entre o horizonte superficial e subsuperficial, lhe conferindo uma forte suscetibilidade a erosão. O Nitossolo não apresentou grande diferenciação no tamanho dos agregados, exceto no horizonte Bw, onde a redução no tamanho dos agregados se associaram a mudança morfológica da estrutura do solo.AbstractThis research aims to study the vulnerability to soil erosion of the contact zone of the sandstone Formation Caiuá with basalt of the Serra Geral Formation, in the municipality of Araruna, Paraná Northwest Region, giving focus to the role of the stability of the current structure of soils, considering the changes produced by the forms of use and occupation of the area. The analysis also considered variations of morphological characteristics of soils in profile and along the lithosactivity (pedological system), as well as your reflexes in the generation of sectors more or less susceptible to erosion in the shed. For the survey of the soils along the strand, the procedures proposed by the Structural Analysis of the Pedological Coverage and the collection of samples for the determination of the granulometry and stability of aggregates were used. The results indicated the action of the lateral and vertical water flows, acting on the transformation of the soil horizons along the slope and a variation of the structural stability associated with the morphological characteristics of the soils and the type of use and management used. The Argisols presented small aggregates and a textural gradient between the surface and subsurface horizon, giving it a strong susceptibility to erosion. The Nitossolo did not show great differentiation in the size of the aggregates, except in the Bw horizon, where the reduction in the size of the aggregates was associated to the morphological change of the soil structure.Keywords: structural analysis of the soil cover, stability of aggregates, susceptibility to erosion, pedological systems.

Determination of the Role of the Carboxyl-terminal Leucine-122 in FMN-binding Protein by Mutational and Structural Analysis

2007 ◽  
Vol 141 (4) ◽  
pp. 459-468 ◽  
Author(s):  
M. Kitamura ◽  
K. Terakawa ◽  
H. Inoue ◽  
T. Hayashida ◽  
K. Suto ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Binding Protein ◽  
Carboxyl Terminal

scholarly journals The contribution of methionine to the stability of the Escherichia coli MetNIQ ABC transporter-substrate binding protein complex

2015 ◽  
Vol 396 (9-10) ◽  
pp. 1127-1134 ◽  
Author(s):  
Phong T. Nguyen ◽  
Qi Wen Li ◽  
Neena S. Kadaba ◽  
Jeffrey Y. Lai ◽  
Janet G. Yang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Complex Formation ◽  
Dissociation Constant ◽  
Binding Protein ◽  
Crystallographic Analysis ◽  
E Coli ◽  
Multiple Conformations ◽  
The Stability

Abstract Despite the ubiquitous role of ATP-binding cassette (ABC) importers in nutrient uptake, only the Escherichia coli maltose and vitamin B12 ABC transporters have been structurally characterized in multiple conformations relevant to the alternating access transport mechanism. To complement our previous structure determination of the E. coli MetNI methionine importer in the inward facing conformation (Kadaba et al. (2008) Science 321, 250–253), we have explored conditions stabilizing the outward facing conformation. Using two variants, the Walker B E166Q mutation with ATP+EDTA to stabilize MetNI in the ATP-bound conformation and the N229A variant of the binding protein MetQ, shown in this work to disrupt methionine binding, a high affinity MetNIQ complex was formed with a dissociation constant measured to be 27 nm. Using wild type MetQ containing a co-purified methionine (for which the crystal structure is reported at 1.6 Å resolution), the dissociation constant for complex formation with MetNI is measured to be ∼40-fold weaker, indicating that complex formation lowers the affinity of MetQ for methionine by this amount. Preparation of a stable MetNIQ complex is an essential step towards the crystallographic analysis of the outward facing conformation, a key intermediate in the uptake of methionine by this transport system.

scholarly journals Exploring the Role of L10 Loop in New Delhi Metallo-β-lactamase (NDM-1): Kinetic and Dynamic Studies

Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5489
Author(s):  
Alessandra Piccirilli ◽  
Emanuele Criscuolo ◽  
Fabrizia Brisdelli ◽  
Paola Sandra Mercuri ◽  
Sabrina Cherubini ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Amino Acid ◽  
Double Mutant ◽  
Amino Acid Substitutions ◽  
New Delhi ◽  
Kinetic Behavior ◽  
Dynamic Studies ◽  
The Stability

Four NDM-1 mutants (L218T, L221T, L269H and L221T/Y229W) were generated in order to investigate the role of leucines positioned in L10 loop. A detailed kinetic analysis stated that these amino acid substitutions modified the hydrolytic profile of NDM-1 against some β-lactams. Significant reduction of kcat values of L218T and L221T for carbapenems, cefazolin, cefoxitin and cefepime was observed. The stability of the NDM-1 and its mutants was explored by thermofluor assay in real-time PCR. The determination of TmB and TmD demonstrated that NDM-1 and L218T were the most stable enzymes. Molecular dynamic studies were performed to justify the differences observed in the kinetic behavior of the mutants. In particular, L218T fluctuated more than NDM-1 in L10, whereas L221T would seem to cause a drift between residues 75 and 125. L221T/Y229W double mutant exhibited a decrease in the flexibility with respect to L221T, explaining enzyme activity improvement towards some β-lactams. Distances between Zn1-Zn2 and Zn1-OH- or Zn2-OH- remained unaffected in all systems analysed. Significant changes were found between Zn1/Zn2 and first sphere coordination residues.

scholarly journals The Degree Of Ambiguity Of Homonymous Syntactic Structures In The Bosnian Language

2017 ◽  
Vol 1 ◽  
pp. 127-136
Author(s):  
Jasmin Hodžić
Keyword(s):  
Native Speakers ◽  
Syntactic Ambiguity ◽  
Syntactic Structures ◽  
The Stability

In this paper has been specifi cally considered the issue of the potential and the actual syntactic ambiguity (or syntactic homonymy) which has led to the results indicating that the existence of ambiguity in syntax is not negligible, and that the role of the context in the analysis of the syntactic ambiguity is not as it has been assumed. A selected number of examples have been presented to native speakers in order to assess the meaning. The results of this questionnaire show that the native speakers have confi rmed the ambiguity of all the sentences. Ambiguity has been additionally analyzed through the calculation of the degree of ambiguity (i.e., determination of the stability of meaning) and the index of the degree of ambiguity (i.e., determination of the consistency of meaning).

scholarly journals IMPORT SUBSTITUTION: THE BOARDERS OF THE ENERGY SECURITY

2016 ◽  
pp. 180-187
Author(s):  
N. N. Shvets
Keyword(s):  
Import Substitution ◽  
Developed Countries ◽  
High Tech ◽  
Interstate Cooperation ◽  
Electric Equipment ◽  
National Production ◽  
The Stability ◽  
Globalized World

The article analyzes issues of import substitution in national production and determination of its effective scale considering the country's involvement to international division of labor and an important role of interstate cooperation in today's globalized world. The relevance of the study relies on the fact, that unfavorable global economic and politic situation in 2014-2015 raised concerns among the Russian authorities and the society in general about the stability of the economy and the necessity to increase its independence and self-sustainability. Sectoral economic sanctions imposed by western developed countries could potentially lead to disruptions in the supply of components and equipment that ensure the operation of power facilities. Currently power companies are influenced by the external economic situation and the devaluation of the national currency. As the result, goods of foreign manufacture have become significantly more expensive and opportunities for power companies to realize their investing and repair programs have been reduced. Thereby there is a high importance of developing the substitution-oriented production of the high-tech electric equipment within the Russian Federation's territory. Import substitution issues are closely related to the governmental industrial policy. The programs of the national production development need huge investments and that's why issues of economic effectiveness evaluation are highly relevant. But balances between economy's specialization and diversification, import substitution and export orientation are also highly important. Such measures directed at artificial import rationing as sanctions against foreign goods, creating favorable competitive environment for national producers, governmental grants could in prospect lead to a stagnation of the economy.

scholarly journals Regulation of phenobarbital-inducible cytochrome P-450s in rat and mouse liver following dexamethasone administration and hypophysectomy

1988 ◽  
Vol 254 (3) ◽  
pp. 789-797 ◽  
Author(s):  
R R Meehan ◽  
L M Forrester ◽  
K Stevenson ◽  
N D Hastie ◽  
A Buchmann ◽  
...  
Keyword(s):  
Species Difference ◽  
Potent Inducer ◽  
The Difference ◽  
The Stability ◽  
And Function ◽  
Synthetic Glucocorticoids ◽  
Cytochrome P 450 ◽  
Hepatic Cytochrome

Cytochrome P-450s are a superfamily of haem-containing proteins involved in the metabolism of foreign compounds, as well as a variety of endogenous molecules. The hepatic levels and function of this diverse group of enzymes are determined by both constitutive and xenobiotic regulators. To examine the role of constitutive factors in cytochrome P-450 regulation, the levels of three distinct groups of phenobarbital-inducible hepatic cytochrome P-450s were studied following dexamethasone-treatment or hypophysectomy. In the mouse, dexamethasone was a potent inducer of proteins within the PB1 (subfamily IIC), PB2c (family III) and PB3 (subfamily IIB) families. These findings were strikingly different from the effects in the rat where essentially no effect on PB3 expression and indeed suppression of proteins related to PB1 was observed. Determination of mRNA concentration indicated that the difference was at the level of transcription. These findings indicate that synthetic glucocorticoids have the potential to be potent phenobarbital-like inducing agents. In the mouse hypophysectomy, like dexamethasone, induced hepatic mRNA of P-450 from families P-450IIB, P-450IIC and P-450III. Again a species difference was observed as this treatment had essentially no effect in the rat. These data in the mouse indicate that factors produced in the pituitary can either affect the transcription rate of phenobarbital and dexamethasone-inducible P-450 genes or influence the stability of their mRNAs.

scholarly journals Composition and stability of complexes of Ephedrine hydrochloride with Ni2+, Zn2+, and Cd2+ as toxic ions

2003 ◽  
Vol 71 (2) ◽  
pp. 75-88
Author(s):  
Nabawia EL Guindi
Keyword(s):  
Metal Ions ◽  
Chelating Agent ◽  
Cadmium Ions ◽  
Nickel Zinc ◽  
Ephedrine Hydrochloride ◽  
Stability Of Complexes ◽  
Different Temperatures ◽  
The Stability

The complexes of Ephedrine with Nickel, Zinc and Cadmium ions have been investigated spectrophotometricalfy using the method of corresponding solutions [I-3] and pH-metrically using Irving and Rossoti technique [4] Two compositions were observed spectrophotometrically 1 : 1 and 2: 1 (L: M) for concentration of metal ions (0.5 x 10-3 M and 1 x 10-3 M) hile the first composition only predominate at concentration of metal ions (1.5 x 10-3 M and 2 x 10-3 M ). The stability of complexes show that complexes of Ni2+ are more stable than that of Zn2+ an Cd2+, Moreover, the composition and stabilities of complexes were studied pHmetrically in aqueous medium at 0.1 M NaCl and two different temperatures 30°C and 40°C; hence the value of the free energy change (ΔG°), the enthalpy (ΔH°) and the entropy (ΔS°) were calculated at 30°C. Beside the role of Ephedrine as chelating agent to toxic elements, the complexometric method was used for the determination of Ephedrine in its pure form and in tablets.

A Molecular Approach to Immunoscintigraphy: A Study of the T-Antigen Conformation on the Surface of Tumors

1987 ◽  
Vol 26 (01) ◽  
pp. 1-6 ◽  
Author(s):  
S. Selvaraj ◽  
M. R. Suresh ◽  
G. McLean ◽  
D. Willans ◽  
C. Turner ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Tumor Cell ◽  
T Antigen ◽  
Human Carcinomas ◽  
Animal Tumor ◽  
Synthetic Antigens

The role of glycoconjugates in tumor cell differentiation has been well documented. We have examined the expression of the two anomers of the Thomsen-Friedenreich antigen on the surface of human, canine and murine tumor cell membranes both in vitro and in vivo. This has been accomplished through the synthesis of the disaccharide terminal residues in both a and ß configuration. Both entities were used to generate murine monoclonal antibodies which recognized the carbohydrate determinants. The determination of fine specificities of these antibodies was effected by means of cellular uptake, immunohistopathology and immunoscintigraphy. Examination of pathological specimens of human and canine tumor tissue indicated that the expressed antigen was in the β configuration. More than 89% of all human carcinomas tested expressed the antigen in the above anomeric form. The combination of synthetic antigens and monoclonal antibodies raised specifically against them provide us with invaluable tools for the study of tumor marker expression in humans and their respective animal tumor models.

On The Mechanism Of Heparin-Induced Potentiation Of Platelet Aggregation

1981 ◽  
Author(s):  
M Yamamoto ◽  
K Watanabe ◽  
Y Ando ◽  
H Iri ◽  
N Fujiyama ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Platelet Activation ◽  
Coagulation Factors ◽  
Marked Enhancement ◽  
Matrix Bound ◽  
Induced Aggregation ◽  
Aggregation Of Platelets ◽  
Plasma Heparin

It has been suggested that heparin caused potentiation of aggregation induced by ADP or epinephrine. The exact mechanism of heparin-induced platelet activation, however, remained unknown. In this paper, we have investigated the role of anti-thrombin III ( AT ) in heparin-induced platelet activation using purified AT and AT depleted plasma. When ADP or epinephrine was added to citrated PRP one minute after addition of heparin ( 1 u/ml, porcine intestinal mucosal heparin, Sigma Co. USA ), marked enhancement of platelet aggregation was observed, compared with the degree of aggregation in the absence of heparin. However, in platelet suspensions prepared in modified Tyrode’s solution, heparin exhibited no potentiating effect on platelet aggregation induced by epinephrine or ADP. Potentiation of epinephrine- or ADP-induced platelet aggregation by heparin was demonstrated when purified AT was added to platelet suspensions at a concentration of 20 μg/ml. AT depleted plasma, which was prepared by immunosorption using matrix-bound antibodies to AT, retained no AT, while determination of α1-antitrypsinα2- macroglobulin and fibrinogen in AT depleted plasma produced values which corresponded to those of the original plasma when dilution factor was taken into account. The activities of coagulation factors were also comparable to those of the original plasma. Heparin exhibited potentiating effect on ADP- or epinephrine-induced aggregation of platelets in original plasma, but no effect in AT depleted plasma. When purified AT was added back to AT depleted plasma at a concentration of 20 μg/ml, potentiation of platelet aggregation by heparin was clearly demonstrated.Our results suggest that effect of heparin on platelet aggregation is also mediated by anti-thrombin III.

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