Search results for " ability"
showing 10 items of 240 documents
Impaired parietal magnitude processing in developmental dyscalculia
2007
Summary Developmental dyscalculia (DD) is a specific learning disability affecting the acquisition of school-level mathematical abilities in the context of otherwise normal academic achievement, with prevalence estimates in the order of 3–6% [1] . Behavioural studies show deficits in elementary numerical processing among individuals with pure DD [2,3], indicating that deficits in higher-level mathematical skills may stem from impaired representation and processing of basic numerical magnitude. Adult neuropsychological and neuroimaging research points to the intraparietal sulcus as a key region for the representation and processing of numerical magnitude [4]. This raises the possibility of a…
Isolation and characterization of hydrocarbonoclastic bacteria from Algerian coast
2017
Backgrounds The contamination of marine environments by hydrocarbons represents a global concern with consequences on ecosystems and human health. The removal of HC by physical and/or chemical methods is expensive and disrespectful of the environment. The use of HC degrading bacteria is a good alternative for environmental remediation (bioremediation). Objectives The Algerian coastline is exposed to several types of pollutions, including hydrocarbons. The aim was to explore the bioremediation potential of its contaminated harbors for the first time. Methods To identify the hydrocarbon degrading bacteria seawater samples were collected in Sidi fredj harbor (Algeria) and used to enrichment cu…
Endometrial Receptivity in Natural and Controlled Ovarian-Stimulated Cycles
2011
The development of endometrial receptivity is a prerequisite for successful embryonic implantation in mammals. The receptive status is reached only during a short period of time in the midluteal phase, this being maximal 7 days after the endogenous peak of LH (LH+7), named as the window of implantation (WOI). At this time, the endometrial epithelium acquires the functional ability to support blastocyst adhesion. In ART, controlled ovarian stimulation (COS) induces lower implantation rates per embryo transferred than natural or ovum donation cycles, suggesting suboptimal endometrial development due to the abnormal endocrine/paracrine milieu. Researchers have investigated the functional genom…
A novel thermodynamic approach for the complexation study of toxic metal cations by a landfill leachate
2018
Landfill leachates can contaminate nearby aquifers. The hazards deriving from this contamination also depend on the chemical speciation of various contaminants. A novel approach is proposed here to face this problem from a chemical thermodynamics point of view. The complexing ability of the soluble fraction of a landfill leachate (collected from Bellolampo, Palermo, Italy) towards Pb2+, Cd2+ and Cu2+ has been investigated at T = 298.15 K in NaClaq at I = 0.1 mol dm−3. The soluble fraction of the landfill leachate was first characterized by different analytical techniques. Then, its acid–base properties were studied by ISE-H+ potentiometric titrations and modelled by the so-called diprotic-l…
Sequestration of alkyltin(IV) cations by complexation with amino-polycarboxylic chelating agents
2013
Abstract The binding capacity of four amino-polycarboxylic ligands (APCs) [nitrilotriacetate (NTA), ethylenediamine- N , N , N′ , N′ -tetraacetate (EDTA), (S,S)-ethylenediamine- N , N ′-disuccinic acid (S,S-EDDS) and diethylenetriamine- N , N , N′ , N″ , N″ -pentaacetate (DTPA)] towards mono-, di- and tri-alkyltin(IV) cations [(CH 3 )Sn 3 + , (CH 3 ) 2 Sn 2 + , (C 2 H 5 ) 2 Sn 2 + , (CH 3 ) 3 Sn + or (C 2 H 5 ) 3 Sn + ] was studied, in aqueous solutions, by ISE-H + potentiometry, at I = 0.1 mol L − 1 (NaCl) and at T = 298.15 K. In all the systems R x Sn (4 − x)+ − APC (R = CH 3 or C 2 H 5 ) a strong 1:1 species is formed together with protonated, hydroxo and dinuclear complexes. The valu…
Crystal Structure and Host-Guest Binding Ability of Three Types of Pillar[5]arenes
2015
A systematic research of the structural characterization and the host-guest binding abilities between three types of pillar[5]arenes 3–5 (3 for Structure Type I, 4 for Structure Type II and 5 for Structure Type III) is carried out by 1H NMR measurements and X-ray study. The results show that the configurations or symmetry of their cavities not only have large difference in these three types of pillar[5]arenes, but also have more or less variations even in the same structure type or the same host locked different guests such as crystals of 3a–3b, 4a–4d. On the other hand, the complexation behavior of pillar[5]arenes with 1,4-dibromobutane (DBB) is affected by the different symmetrical struct…
Utilization of water glass as an activator in the manufacturing of cementitious materials from waste by-products
1987
Abstract In the present paper, the possibility of producing new-type cementless building materials is discussed when water glass as an activating agent is used. The experimental data are presented for a set of raw materials which normally do not show any binding ability. However, if they undergo some physico-chemical treatment and water glass is used, a solid structure of the material is formed. According to the method described here, lots of different mineral waste by-products could be activated, thus gaining binding properties.
Calorimetric and viscosimetric investigation of the interaction between α,β-polyasparthydrazide and sodium dodecyl sulfate micelles
1993
Abstract The interaction between α,β-polyasparthydrazide (PAHy) and sodium dodecyl sulfate (SDS) micelles in aqueous solution was investigated by calorimetry and viscosimetry. The dependence of the enthalpic effect due to this interaction upon the surfactant concentration was rationalized in terms of a progressive binding of SDS micelles to the polymeric backbone. The analysis of the calorimetric data allow evaluation of the binding ability of SDS micelles to the polymeric chain. The viscosimetric behavior of SDS plus PAHy aqueous solutions, discussed in terms of the parameter F [F = ηrel(PAHy) + ηrel(PAHy) − ηrel(SDS+PAHy)], confirms the occurence of the interaction between SDS micelles an…
15-years mortality in asthma-COPD overlap syndrome (ACOS) elderly population
2015
Background: The coexistence of asthma and chronic obstructive pulmonary disease (Asthma-COPD Overlap Syndrome: ACOS) is increasingly recognized. Data about the prevalence of ACOS in the elderly and its prognostic implications are unknown. Aim: To evaluate the long-term mortality of ACOS in an elderly population. Methods: 1970 subjects, aged >65 yrs, were enrolled in the population-based SA.R.A. Study. ACOS was defined as: not fully reversible airflow limitation + a) history of asthma or b) very positive bronchodilator test (increase in FEV1 ≥15% and ≥400 ml) + atopy + weezing. The prevalence of ACOS and 15-years mortality rates were assessed in 1063 subjects with complete clinical, lung fun…
Formation and Stability of Cadmium(II)/Phytate Complexes by Different Electrochemical Techniques. Critical Analysis of Results
2010
In the present work the stability constants of various cadmium(II)/phytate (Phy) species were determined at T = 298.15 K in NaNO3(aq) at I = 0.1 mol·L−1 by DP-ASV (Differential Pulse Anodic Stripping Voltammetry) and by potentiometric titrations using an ISE-Cd2+. Cyclic voltammograms were also recorded to check the electrochemical behavior of cadmium in the presence of phytate. The results were analyzed together with previous data determined by ISE-H+ measurements. Data obtained were used to provide an exhaustive speciation scheme for the phytate/cadmium(II) system at different conditions, as well as a comprehensive representation of the binding ability of phytate toward cadmium(II). Diffe…