Search results for "amine"
showing 10 items of 7299 documents
Thermodynamic Parameters for the Protonation of Poly(allylamine) in concentrated LiCl(aq) and NaCl(aq)
2004
The acid-base properties of poly(allylamine) (MW ) 15 kDa) were determined by potentiometry and calorimetry in aqueous solutions at t ) 25 °C. Potentiometric measurements were carried out in a wide range of ionic strengths (0.1 e I/molâL-1 e 5.0) in NaCl(aq) and LiCl(aq), while enthalpy changes for the protonation of poly(allylamine) were determined by calorimetry in the same ionic strength range but only in NaCl(aq). Analysis of the experimental data was carried out using two different models: the first based on a modified Henderson-Hasselbalch two parameter equation and the second on the three parameter equation proposed by Ho¨gfeldt. Protonation constants are given for both models and io…
Talent identification in soccer using a one-class support vector machine
2019
Abstract Identifying potential future elite athletes is important in many sporting events. The successful identification of potential future elite athletes at an early age would help to provide high-quality coaching and training environments in which to optimize their development. However, a large variety of different skills and qualities are needed to succeed in elite sports, making talent identification generally a complex and multifaceted problem. Due to the rarity of elite athletes, datasets are inherently imbalanced, making classical statistical inference difficult. Therefore, we approach talent identification as an anomaly detection problem. We trained a nonlinear one-class support ve…
The composition of data economy : a bibliometric approach and TCCM framework of conceptual, intellectual and social structure
2022
Purpose The data economy mainly relies on the surveillance capitalism business model, enabling companies to monetize their data. The surveillance allows for transforming private human experiences into behavioral data that can be harnessed in the marketing sphere. This study aims to focus on investigating the domain of data economy with the methodological lens of quantitative bibliometric analysis of published literature. Design/methodology/approach The bibliometric analysis seeks to unravel trends and timelines for the emergence of the data economy, its conceptualization, scientific progression and thematic synergy that could predict the future of the field. A total of 591 data between 200…
Grand theories or design guidelines? : Perspectives on the role of theory in computing education research
2022
A rich body of empirically grounded results and a solid theory base have often been viewed as signs of a mature discipline. Many disciplines have frequently debated what they should accept as legitimate kinds of theories, the proper roles of theory, and appropriate reference disciplines. Computing education research (CER) in particular has seen a growing number of calls for the development of domain-specific theories for CER, an adaptation of theories from other fields, and engagement with theory-based experimental and predictive research in CER. Many of those calls share the same concerns and aims, yet they use very different vocabulary and lack a consensus over an essential concept: theor…
Effects of histamine on dentate granule cells in vitro
1990
Abstract Hippocampal slices from rat brain were exposed to histamine and related substances in a perfusion chamber. Granule cells of the dentate gyrus were studied with conventional extra- and intracellular recording and a single electrode voltage clamp. Histamine caused, through activation of H 2 -receptors, a small depolarization, an increase in the number of synaptic and action potentials, a block of the long lasting (but not the early) component of spike afterhyperpolarizations and a reduction of the accommodation of action potential firing. These effects were mimicked by forskolin (suggests activation of adenylate cyclase). In voltage clamp, histamine blocked a long lasting calcium-dep…
The origin of the serpentine endemic Minuartia laricifolia subsp. ophiolitica by vicariance and competitive exclusion.
2013
Serpentine soils harbour a unique flora that is rich in endemics. We examined the evolution of serpentine endemism in Minuartia laricifolia, which has two ecologically distinct subspecies with disjunct distributions: subsp. laricifolia on siliceous rocks in the western Alps and eastern Pyrenees and subsp. ophiolitica on serpentine in the northern Apennines. We analysed AFLPs and chloroplast sequences from 30 populations to examine their relationships and how their current distributions and ecologies were influenced by Quaternary climatic changes. Minuartia laricifolia was divided into four groups with a BAPS cluster analysis of the AFLP data, one group consisted only of subsp. ophiolitica, …
Central cholinergic functions in human amyloid precursor protein knock-in/presenilin-1 transgenic mice.
2004
Alzheimer's disease is characterized by amyloid peptide formation and deposition, neurofibrillary tangles, central cholinergic dysfunction, and dementia; however, the relationship between these parameters is not well understood. We studied the effect of amyloid peptide formation and deposition on central cholinergic function in knock-in mice carrying the human amyloid precursor protein (APP) gene with the Swedish/London double mutation (APP-SL mice) which were crossbred with transgenic mice overexpressing normal (PS1wt) or mutated (M146L; PS1mut) human presenilin-1. APP-SLxPS1mut mice had increased levels of Abeta peptides at 10 months of age and amyloid plaques at 14 months of age while AP…
An operon for histidine biosynthesis in Streptomyces coelicolor
1973
On the assumption that a cluster of five his genes (eight cistrons) in S. coelicolor corresponds to an operon, a genetic analysis of a constitutive mutant was carried out. This strain has a multi-site mutation localized at the (conventional) right end of the his cluster and is derepressed for at least two enzymes coded by genes of the cluster. The study of suitable heterozygous clones (heteroclones), showed the mutation to be cis-dominant, suggesting that the operator region is affected. Most likely the strain has a deletion connecting the his operon to an adjacent amm (ammonium requirement) operon as demonstrated by its inability to utilize nitrate as nitrogen source and to complement or r…
Genetic polymorphism in dopamine receptor D4 is associated with early body condition in a large population of greater flamingos,Phoenicopterus roseus
2012
Body condition is an important determinant of fitness in many natural populations. However, as for many fitness traits, the underlying genes that regulate body condition remain elusive. The dopamine receptor D4 gene (DRD4) is a promising candidate as dopamine is known to play an important role in the regulation of food intake and the metabolism of both glucose and lipids in vertebrates. In this study, we take advantage of a large data set of greater flamingos, Phoenicopterus roseus, to test whether DRD4 polymorphism predicts early body condition (EBC) while controlling for whole-genome effects of inbreeding and outbreeding using microsatellite multilocus heterozygosity (MLH). We typed 670 o…
Functional analysis of yeast gene families involved in metabolism of vitamins B1and B6
2002
In order to clarify their physiological functions, we have undertaken a characterization of the three-membered gene families SNZ1-3 and SNO1-3. In media lacking vitamin B(6), SNZ1 and SNO1 were both required for growth in certain conditions, but neither SNZ2, SNZ3, SNO2 nor SNO3 were required. Copies 2 and 3 of the gene products have, in spite of their extremely close sequence similarity, slightly different functions in the cell. We have also found that copies 2 and 3 are activated by the lack of thiamine and that the Snz proteins physically interact with the thiamine biosynthesis Thi5 protein family. Whereas copy 1 is required for conditions in which B(6) is essential for growth, copies 2 …