Crucial Point (crucial + point)

Distribution by Scientific Domains


Selected Abstracts


Modified Hadamard transform microchip electrophoresis

ELECTROPHORESIS, Issue 16 2005
Renato Guchardi
Abstract Sensitivity is a crucial point in the development applications for medicine or environmental samples in which the analytes are present in the nanomolar range. Besides further technical development of detection systems, the multiplex sample injection technique can be applied for enhancing the signal-to-noise ratio. Hadamard transform is easily applied to microchip electrophoresis due to the fact that sample injection is generally achieved through cross, double-tee, or tee injector structures. This paper reports the first demonstration of a modified Hadamard transform electrophoresis on a microchip by using an amperometric detector. Contrary to the previous Hadamard applications, the resolution (number of points per unit of time) of electropherograms obtained is independent of the number of injections. [source]


Recrystallization Modeling of AA8XXX Alloys with Cellular Automata Considering Recovering Kinetics,

ADVANCED ENGINEERING MATERIALS, Issue 3 2010
Carmen Schäfer
A through-process modeling scheme for the prediction of recrystallization textures and microstructures after final annealing, subsequent to cold rolling is proposed and applied to a commercial AlFeSi alloy. The heart of the setup is a cellular automaton for modeling of recrystallization which considers changes in dislocation density by recovery and changes in Zener and solute drag due to microchemistry evolution. However, recrystallization is the crucial point in the whole setup, since it leads to significant changes in microstructure and texture. The simulated results are compared to experiments. [source]


A method for fast simulation of multiple catastrophic faults in analogue circuits

INTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 3 2010
Micha, Tadeusiewicz
Abstract The paper offers an efficient method for simulation of multiple catastrophic faults in linear AC circuits. The faulty elements are either open circuits or short circuits. The method exploits the well-known Householder formula in matrix theory to find the node voltages deviations due to the perturbations of some circuit elements. The main achievement of the paper is a systematic method for performing the simulation of all combinations of the multiple catastrophic faults. The method includes two new procedures enabling us to find very efficiently the node impedance matrix of the nominal circuit and inverses of some matrices corresponding to different fault combinations. The procedures are the crucial point of this approach and make it very efficient. Consequently, the amount of the computing power needed to carry out all the simulations is significantly reduced. Numerical examples illustrating the proposed approach are provided. Copyright © 2008 John Wiley & Sons, Ltd. [source]


Issues in pension system design

INTERNATIONAL SOCIAL SECURITY REVIEW, Issue 1 2002
Maria Augusztinovics
External conditions for pension system design and demographic and labour market trends are briefly considered and the latter found decisive. Basic concepts, e.g. social assistance and insurance, redistribution and actuarial fairness, are then introduced. Then it is argued that the "public PAYG versus private funded" dichotomy has attracted an unduly large share of attention in recent pension reform debates, as such institutional changes do not really address the basic problems, while quantitative aspects, the relationship between contribution and replacement rates, have been improperly neglected or shielded by the paradigmatic controversy. The next, crucial point is that traditional, employment-based, earnings-related forms of pension insurance are endangered by new trends on the labour market; hence, new solutions will have to be sought to ensure pension coverage for the entire population. A brief plea for more, relevant and comparative information on pension issues follows. The paper concludes with a concise summary and by contemplating what could and should be expected from the Second World Assembly on Ageing. [source]


Nondestructive characterization of ferrofluids by wide-angle synchrotron light diffraction: crystalline structure and size distribution of colloidal nanoparticles

JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 5 2008
Alexei Vorobiev
The combination of magnetic and nonmagnetic interactions between the colloidal particles in ferrofluids results in various local inter-particle correlations that, in turn, change the macroscopic properties of the whole system. Therefore, characterization of the particle ensemble is a crucial point, allowing optimization of a ferrofluid for a particular application. Here it is shown how the crystal structure of the particles can be easily obtained in a fast synchrotron light diffraction experiment without any special treatment of the ferrofluid sample. Moreover, from the same diffraction patterns, such important parameters as particle mean size and dispersion are retrieved; these are compared with the corresponding parameters obtained from electron microscopy data. A particular problem of magnetite,maghemite transformation in nanoparticles stabilized by the surfactant shell is pointed out. [source]


New tricks of an old molecule: lifespan regulation by p53

AGING CELL, Issue 5 2006
Johannes H. Bauer
Summary As guardian of the genome the tumor suppressor p53 controls a crucial point in protection from cellular damage and response to stressors. Activation of p53 can have beneficial (DNA repair) or detrimental (apoptosis) consequences for individual cells. In either case activation of p53 is thought to safeguard the organism at large from the deleterious effects of various stresses. Recent data suggest that the function of p53 might also play a role in the regulation of organismal lifespan. Increased p53 activity leads to lifespan shortening in mice, while apparent reduction of p53 activity in flies leads to lifespan extension. Although the mechanism by which p53 regulates lifespan remains to be determined, these findings highlight the possibility that careful manipulation of p53 activity during adult life may result in beneficial effects on healthy lifespan. [source]


Evaluation of 08CH18N10T stainless steel corrosion in subcritical water by electrochemical noise analysis

MATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 9 2008
P. Ku
Abstract The corrosion behaviour of pressurized water reactor (PWR) steam generator tube material (08CH18N10T steel) was studied by electrochemical noise (EN) measurements and electrochemical impedance spectroscopy in high-temperature water at 280,°C and 8 MPa. Long-term measurements were performed in two electrolytes: (i) deionised water alkalized to pH25,=,9.5 by KOH; (ii) the same electrolyte with 200 ppm of chlorides added (as KCl). The noise data were processed by two filtering methods and the noise resistance and spectral noise resistance values were calculated. Different contributions to the total impedance were identified and the polarization resistance values were calculated from EIS data. Noise and polarization resistances were compared and the influence of filtering methods was discussed. Instantaneous corrosion data were transformed to integral ones and comparison with mean corrosion current estimated from the oxide thickness was made. It was confirmed that the crucial point of EN analysis is selection of proper cut-off frequency in high-pass fast Fourier transform (HP-FFT). [source]


What it takes to get a herbicide's mode of action.

PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 5 2005
Physionomics, a classical approach in a new complexion
Abstract Discovering new herbicides with novel modes of action is a priority assignment in plant protection research. However, for active compounds identified in greenhouse screens, the crucial point is to tread the most efficient path in determining a herbicide's target site, regarding chance of success, time and research costs. Today, in the literature, molecular (functional genomics, transcriptomics), biochemical (proteomics) and analytical (metabolomics) approaches are particularly discussed. So far, less attention has been focused on the comprehensive physiological profiling of the complex plant system as a procedure which enables new herbicides, with an unknown target site for their mode of action, to be screened rapidly. Here, the concept of an array of ,functional' bioassays is presented which has ultimately been developed from the classical tool of mode of action diagnosis by symptoms. These bioassays are designed to differentiate between the distinct responses of the multiple organization units (plant, tissue, meristematic cell, organelle), developmental stages, types of metabolism (phototrophic, heterotrophic) and physiological processes in the plant organism. The response pattern to a herbicide can be viewed as the end result of changes induced in the molecular and biochemical process chain and should be diagnostic of its physiological mode of action. The results can be interpreted directly or a fingerprint database for all known modes of action to be screened for analogy. The term ,physionomics' is proposed for this comprehensive physiological profiling of the plant system, following the parallel terminology of the molecular and biochemical ,omics' technologies. Physionomics procedures provide a first clue to the mode of action of a new herbicide that can direct more time-consuming and costly molecular, biochemical, histochemical or analytical studies to identify a target site more efficiently. Copyright © 2005 Society of Chemical Industry [source]


Improving in vitro Maturation of Oocytes in the Human Taking Lessons from Experiences in Animal Species

REPRODUCTION IN DOMESTIC ANIMALS, Issue 1 2001
J Smitz
One to three per cent of infertile women develop severe ovarian hyperstimulation syndrome after superovulation for assisted reproduction treatment (ART). This severe complication can be avoided when oocytes are obtained at an immature stage (germinal vesicle stage) out of small or medium-sized follicles. This hypothesis has been tested in several infertile women, but clinical pregnancies are disappointlingly low. This new approach in ART is still at an experimental phase and this treatment has still to be improved before routine clinical application. Experimental work in animals and humans suggest a beneficial effect in providing a short preliminary pretreatment with follicle-stimulating hormone to select for a developing cohort of follicles. The aspiration of oocyte cumulus complexes is carried out with a short needle applying reduced aspiration pressure. A crucial point is to provide the appropriate culture environment for the immature oocytes. An optimal cumulus-enclosed human oocyte culture system needs to be defined. The composition of the culture medium could be suggested by in vitro work carried out in animal models. As developmental competence is established during the latest phases of oocyte growth and is dependent on the storage of RNA, a prolonged in vitro maturation period (before inducing nuclear maturation) could provide the necessary transcriptional and translational changes. The conditions to achieve this improved cytoplasmic maturation by prolonging the in vitro culture remain to be defined. More objective noninvasive parameters for oocyte maturity are also needed to pursue research in this field. [source]


Distribution and ecophysiology of the nitrifying bacteria emphasizing cultured species

FEMS MICROBIOLOGY ECOLOGY, Issue 1 2001
Hans-Peter Koops
Abstract Nitrification is an important factor in the global nitrogen cycle. Therefore, an increasing number of publications deal with in situ studies of natural bacterial populations participating in this process. However, some crucial points complicate suchlike investigations. At the time being, a total of 25 species of ammonia-oxidizers and eight species of nitrite-oxidizers are cultured but the existence of many more species has been indicated by molecular in situ investigations. With that, only a part of the existing nitrifiers has been defined via isolation and subsequent physiological and molecular characterization. Furthermore, the distribution patterns of the distinct species of nitrifiers depend on various environmental parameters. Hence the composition of nitrifying bacterial communities is complex and divers in heterogeneous habitats. In consequence of the above-mentioned problems, the representation of nitrifying community structures obtained from in situ investigations often has been incomplete and unbalanced in many respects. Polyphasic approaches, applying a combination of classical as well as molecular methods in parallel, could help to find the way for overcoming these problems in the future. Isolation and characterization of as many as possible new species seems to be one of the most important missing steps to advance at this way. [source]


HOW TO ANALYZE IMMEDIATE EXPERIENCE:

METAPHILOSOPHY, Issue 3 2008
AND THE IDEA OF PHENOMENOLOGY, HINTIKKA, HUSSERL
Abstract: This article discusses Jaakko Hintikka's interpretation of the aims and method of Husserl's phenomenology. I argue that Hintikka misrepresents Husserl's phenomenology on certain crucial points. More specifically, Hintikka misconstrues Husserl's notion of "immediate experience" and consequently fails to grasp the functions of the central methodological tools known as the "epoché" and the "phenomenological reduction." The result is that the conception of phenomenology he attributes to Husserl is very far from realizing the philosophical potential of Husserl's position. Hence if we want a fruitful rapprochement between analytical philosophy and Continental phenomenology of the kind that is Hintikka's ultimate aim, then Hintikka's account of Husserl needs correcting on a number of crucial points. [source]


A Buddhist Colonization?: A New Perspective on the Attempted Alliance of 1910 Between the Japanese S,t,sh, and the Korean W,njong

RELIGION COMPASS (ELECTRONIC), Issue 5 2010
Hwansoo Kim
One of the most infamous events in modern Japanese and Korean Buddhist history was the alliance attempted between the Japanese S,t,sh, (S,t, Sect) and the Korean Wo,njong (Complete Sect) in late 1910, 46 days after Japan annexed Korea. The Japanese Buddhist priests involved have been characterized as colonialists and imperialists trying to conquer Korean Buddhism on behalf of their imperial government while the Korean monks orchestrating the initiative have been cast as traitors, collaborators, and sellers of Korean Buddhism. All the key figures,Takeda (1863,1911), Yi Hoegwang (1862,1933), clergy from the Wo,njong and S,t,sh,, and colonial government officials,are portrayed in historiographies as villains. But the politicized narrative of the alliance has neglected two crucial points among others. First, behind Yi and Takeda was a bilingual Korean monk named Kim Yo,nggi (1878,?) who played a key role in this movement. Second, the S,t,sh, was not enthusiastic about the alliance, which reveals that Takeda's vision for the alliance was at odds with that of the heads of his sect. This article draws upon these two findings in overlooked primary sources,about the influential players, the Japanese and Korean sects' conflicted motives, and the governments' responses,to draw out the complex power relationships and discourses surrounding the attempted alliance. [source]