General Overview (general + overview)

Distribution by Scientific Domains


Selected Abstracts


Deliberate Practice and Acquisition of Expert Performance: A General Overview

ACADEMIC EMERGENCY MEDICINE, Issue 11 2008
K. Anders Ericsson PhD
Traditionally, professional expertise has been judged by length of experience, reputation, and perceived mastery of knowledge and skill. Unfortunately, recent research demonstrates only a weak relationship between these indicators of expertise and actual, observed performance. In fact, observed performance does not necessarily correlate with greater professional experience. Expert performance can, however, be traced to active engagement in deliberate practice (DP), where training (often designed and arranged by their teachers and coaches) is focused on improving particular tasks. DP also involves the provision of immediate feedback, time for problem-solving and evaluation, and opportunities for repeated performance to refine behavior. In this article, we draw upon the principles of DP established in other domains, such as chess, music, typing, and sports to provide insight into developing expert performance in medicine. [source]


Perfusion-based functional magnetic resonance imaging,

CONCEPTS IN MAGNETIC RESONANCE, Issue 1 2003
Afonso C. Silva
Abstract The measurement of cerebral blood flow (CBF) is a very important way of assessing tissue viability, metabolism, and function. CBF can be measured noninvasively with magnetic resonance imaging (MRI) by using arterial water as a perfusion tracer. Because of the tight coupling between neural activity and CBF, functional MRI (fMRI) techniques are having a large impact in defining regions of the brain that are activated due to specific stimuli. Among the different fMRI techniques, CBF-based fMRI has the advantages of being specific to tissue signal change, a critical feature for quantitative measurements within and across subjects, and for high-resolution functional mapping. Unlike the conventional blood oxygenation level dependent (BOLD) technique, the CBF change is an excellent index of the magnitude of neural activity change. Thus, CBF-based fMRI is the tool of choice for longitudinal functional imaging studies. A review of the principles and theoretical backgrounds of both continuous and pulsed arterial spin labeling methods for measuring CBF is presented, and a general overview of their current applications in the field of functional brain mapping is provided. In particular, examples of the use of CBF-based fMRI to investigate the fundamental hemodynamic responses induced by neural activity and to determine the signal source of the most commonly used BOLD functional imaging are reviewed. © 2003 Wiley Periodicals, Inc. Concepts Magn Reson 16A: 16,27, 2003 [source]


Advances in Biomimetic and Nanostructured Biohybrid Materials

ADVANCED MATERIALS, Issue 3 2010
Eduardo Ruiz-Hitzky
Abstract The rapid increase of interest in the field of biohybrid and biomimetic materials that exhibit improved structural and functional properties is attracting more and more researchers from life science, materials science, and nanoscience. Concomitant results offer valuable opportunities for applications that involve disciplines dealing with engineering, biotechnology, medicine and pharmacy, agriculture, nanotechnology, and others. In the current contribution we collect recent illustrative examples of assemblies between materials of biological origin and inorganic solids of different characteristics (texture, structure, and particle size). We introduce here a general overview on strategies for the preparation and conformation of biohybrids, the synergistic effects that determine the final properties of these materials, and their diverse applications, which cover areas as different as tissue engineering, drug delivery systems, biosensing devices, biocatalysis, green nanocomposites, etc. [source]


Tidal Current Energy Technologies

IBIS, Issue 2006
PETER L FRAENKEL
This paper sets the context for the development of tidal current technology in the face of impending climate change and so called ,peak oil'. Siting requirements are specified for tidal turbines and a general overview of the different technologies under development is given. Specific and detailed descriptions of leading Marine Current Turbine's technology are also highlighted. The paper considers the likely environmental impact of the technology, considering in particular possible (perceived and real) risks to marine wildlife, including birds. It concludes by indicating the planned future developments, and the scale and speed of implementation that might be achieved. [source]


Social Policymaking and Its Institutional Basis: Transition of The Chinese Social Security System

INTERNATIONAL SOCIAL SECURITY REVIEW, Issue 2 2006
Ka Lin
This article discusses Chinese social policy development in response to the growth of the market economy. It provides a general overview of the system's evolution in three stages: (1) the pre-reform period when a system of enterprise welfare was in operation; (2) a period of system transition; (3) the stage when state welfare began to take shape. These developmental trends are interpreted on the basis of three types of institutional relations: the State-enterprise relation, the enterprise- (or employer-) employee relation, and the individual/worker-State relation. Moreover, the discussion deals with policy perceptions at each stage of the developmental process. Based on these analyses, it illustrates the transformation of the Chinese social security system in a broad socioeconomic and political context, where China struggled to establish a modern, market-based enterprise system. The paper thus expounds issues of socialism, market forces and the power of organized labour. [source]


Rhinoceros behaviour: implications for captive management and conservation

INTERNATIONAL ZOO YEARBOOK, Issue 1 2006
M. HUTCHINS
All species of rhinoceros are, to varying degrees, threatened with extinction because of poaching, habitat loss, human-rhinoceros conflict, hunting and civil unrest. Clearly the threats facing the five remaining species (Black rhinoceros Diceros bicornis, White rhinoceros Ceratotherium simum, Greater one-horned rhinoceros Rhinoceros unicornis, Javan rhinoceros Rhinoceros sondaicus and Sumatran rhinoceros Dicerorhinus sumatrensis) are anthropogenic. Although many disciplines are important for conservation, understanding the behaviour characteristics of a species should be considered a key component when developing wildlife-management and conservation strategies. A general overview of the behaviour of rhinoceros is presented, addressing ecology and social organization, activity and habitat use, feeding strategies, courtship and reproduction, and anti-predator behaviour. The implications of behavioural studies for successful management and husbandry of rhinoceros in captivity are discussed in sections on group size and composition, enclosure design and enrichment programmes, activity patterns, introductions, reproduction, hand-rearing, and health and stress. Finally, there is some discussion about the implications of this knowledge for in situ conservation in relation to designing protected areas, further aspects of animal health and stress, and reintroduction and translocation. A detailed understanding of rhinoceros behaviour is important for survival both in range-country protected areas and captivity, and such knowledge should be used to provide the most appropriate animal care and environments for these species. [source]


,Best research practice': in pursuit of methodological rigour

JOURNAL OF ADVANCED NURSING, Issue 3 2001
Frances Maggs-Rapport BA MPhil CertEd FRSA
,Best research practice': in pursuit of methodological rigour Rationale.,This paper is based on the rationale that misuse of methodological notions in research publications lays research studies open to criticism and dismissal. Aim.,In search of ,best research practice', this paper aims to examine the different qualities of four major qualitative methodologies: ethnography, descriptive phenomenology, interpretative phenomenology/hermeneutics and critical social theory. Design.,The study presents a critical overview of methodological decision-making, illustrating the sorts of issues researchers must consider in order to justify to the readership and to themselves the employment of a particular methodology. This is presented alongside a general overview of qualitative research and a précis of each of the major qualitative methodologies. The paper describes the methodologies, salient features, and examines methodological similarities and differences. The paper concludes by examining the need for methodological rigour within the framework of the National Health Service (NHS) Executive's drive for evidence-based practice in health care. Recommendations.,It is hoped that the paper will stimulate a deeper exploration of methodological rigour in future research publications. [source]


Topographical and laminar distribution of cortical input to the monkey entorhinal cortex

JOURNAL OF ANATOMY, Issue 2 2007
A. Mohedano-Moriano
Abstract Hippocampal formation plays a prominent role in episodic memory formation and consolidation. It is likely that episodic memory representations are constructed from cortical information that is mostly funnelled through the entorhinal cortex to the hippocampus. The entorhinal cortex returns processed information to the neocortex. Retrograde tracing studies have shown that neocortical afferents to the entorhinal cortex originate almost exclusively in polymodal association cortical areas. However, the use of retrograde studies does not address the question of the laminar and topographical distribution of cortical projections within the entorhinal cortex. We examined material from 60 Macaca fascicularis monkeys in which cortical deposits of either 3H-amino acids or biotinylated dextran-amine as anterograde tracers were made into different cortical areas (the frontal, cingulate, temporal and parietal cortices). The various cortical inputs to the entorhinal cortex present a heterogeneous topographical distribution. Some projections terminate throughout the entorhinal cortex (afferents from medial area 13 and posterior parahippocampal cortex), while others have more limited termination, with emphasis either rostrally (lateral orbitofrontal cortex, agranular insular cortex, anterior cingulate cortex, perirhinal cortex, unimodal visual association cortex), intermediate (upper bank of the superior temporal sulcus, unimodal auditory association cortex) or caudally (parietal and retrosplenial cortices). Many of these inputs overlap, particularly within the rostrolateral portion of the entorhinal cortex. Some projections were directed mainly to superficial layers (I,III) while others were heavier to deep layers (V,VI) although areas of dense projections typically spanned all layers. A primary report will provide a detailed analysis of the regional and laminar organization of these projections. Here we provide a general overview of these projections in relation to the known neuroanatomy of the entorhinal cortex. [source]


Novel tools and resources for evidence-based practice in psychology

JOURNAL OF CLINICAL PSYCHOLOGY, Issue 7 2007
Barbara B. Walker
Given the vast proliferation of scientific research in the behavioral and social sciences, there is a growing need for psychologists to be able to access the most current, clinically relevant research quickly and efficiently and integrate this information into patient care. In response to a similar need within the field of medicine, evidence-based medicine took hold in the early 1990s to provide both a framework and set of skills for translating research into practice. Since then, this method has been adopted by every major health care profession including psychology, and is now widely known as evidence-based practice (EBP). In this article, the authors present a general overview of the skills required for EBP along with an introduction to some of the tools and resources that have been developed in other health care professions to support EBP. Using a case example, we illustrate how these tools and resources can be applied in psychological settings. © 2007 Wiley Periodicals, Inc. J Clin Psychol 63: 633,642, 2007. [source]


Joining the dots: The links between education and health and implications for Indigenous children

JOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 12 2009
Vanessa Johnston
Abstract This paper provides a general overview of the literature investigating the nexus between education and health; discussing the relationship between these domains at individual, family and community levels. We then briefly examine the programme and research implications of such a framework for interventions aimed at improving education and health, with specific reference to young Indigenous Australians. We find that while education and health are inextricably linked, throughout the life course and at different levels of influence, there is less empirical work exploring this relationship in an Indigenous context. Given the gravity of literacy and numeracy failure rates in school-based education and its potential impact on Indigenous health, we assert an urgent case for rigorous research into interventions that address the barriers to effectiveness in implementing quality educational experiences and opportunities for Indigenous children. [source]


Drug substances presented as sulfonic acid salts: overview of utility, safety and regulation

JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 3 2009
David P. Elder
Abstract Objectives Controlling genotoxic impurities represents a significant challenge to both industry and regulators. The potential for formation of genotoxic short-chain alkyl esters of sulfonic acids during synthesis of sulfonic acid salts is a long-standing regulatory concern. This review provides a general overview of the utility of sulfonic acids as salt-forming moieties and discusses strategies for effectively minimizing the potential for alkyl sulfonate formation during the synthesis and processing of sulfonate salt active pharmaceutical ingredients. The potential implications of the recent establishment of a substantial human threshold dose for ethyl methanesulfonate for the safety assessment of alkyl sulfonates in general are also discussed. Key findings The formation of alkyl sulfonates requires highly acidic conditions, possibly combined with long reaction times and/or elevated temperatures, to generate significant amounts, and these conditions are most unlikely to be present in the synthesis of active pharmaceutical ingredient sulfonate salts. It is possible to design salt formation conditions, using a short-chain alcohol as solvent, to manufacture sulfonate salts that are essentially free of alkyl sulfonate impurities. Processes using non-acidic conditions such as ethanol recrystallization or wet granulation should not raise any concerns of alkyl sulfonate formation. Summary An understanding of the mechanism of formation of alkyl sulfonates is critical in order to avoid restricting or over-controlling sulfonic acid salts, which have many technical advantages as pharmaceutical counterions. Recent regulatory acceptance of a human threshold limit dose of 2 mg/kg per day for ethyl methanesulfonate, indicating that its toxicological risks have previously been considerably overestimated, could signal the beginning of the end over safety concerns on alkyl sulfonate residues, thus removing a major constraint from the exploitation of sulfonic acid counterions. [source]


162 Interactions Between Planktonic Microalgae and Protozoan Grazers

JOURNAL OF PHYCOLOGY, Issue 2003
U. Tillmann
For an algal bloom to develop, the growth rate of the bloom-forming species must exceed the sum of all loss processes. Among these loss processes, grazing is generally believed to be one of the more important factors. Based on numerous field studies it is now recognised that microzooplankton are dominant consumers of phytoplankton in both open ocean and coastal waters. Heterotrophic protists, a major component of microzooplankton communities, constitute a vast complex of diverse feeding strategies and behaviour which allow them access to even the larger phytoplankton species. A number of laboratory studies have shown the capability of different protistan species to feed and grow on bloom forming algal species. Because of short generation times, their ability for fast reaction to short-term variation in food conditions enables phagotrophic protists to fulfil the function of a heterotrophic buffer, which might balances the flow of matter in case of phytoplankton blooms. The importance of grazing as control of microalgae becomes most apparent by its failure; if community grazing controls initial stages of bloom development, there simply is no bloom. However, if a certain algal species is difficult to graze, e.g. due to specific defence mechanisms, a reduced grazing pressure will certainly favour bloom development. The present contribution will provide a general overview on the interactions between planktonic microalgae and protozoan grazers with special emphasis on species-specific interactions and algal defence strategies against protozoan grazers. [source]


Multidisciplinary Teaming to Promote Effective Management of Type 1 Diabetes for Adolescents

JOURNAL OF SCHOOL HEALTH, Issue 6 2001
MaryAnn Tapper Strawhacker BSN, RN Special Education Nursing Consultant
ABSTRACT: Intensive diabetes therapy can reduce the long-term microvascular complications of Type 1 diabetes and improve glucose control. Managing the demands of intensive therapy however, often poses a burden on adolescents and their families. Through multidisciplinary teaming, the school health office can facilitate active participation in treatment, coordinate services, and maximize use of community resources. This paper presents a general overview of intensive diabetes therapy, psychosocial implications of chronic illness in adolescence, effects of chronic illness on the family, and behavior change strategies to improve adherence with disease management guidelines. [source]


Skeletal tissue engineering using silk biomaterials

JOURNAL OF TISSUE ENGINEERING AND REGENERATIVE MEDICINE, Issue 2-3 2008
Ana C. MacIntosh
Abstract Silks have been proposed as potential scaffold materials for tissue engineering, mainly because of their physical properties. They are stable at physiological temperatures, flexible and resist tensile and compressive forces. Bombyx mori (silkworm) cocoon silk has been used as a suture material for over a century, and has proved to be biocompatible once the immunogenic sericin coating is removed. Spider silks have a similar structure to silkworm silk but do not have a sericin coating. This paper provides a general overview on the use of silk protein in biomaterials, with a focus on skeletal tissue engineering. Copyright © 2008 John Wiley & Sons, Ltd. [source]


Thermochemistry, bonding, and reactivity of Ni+ and Ni2+ in the gas phase

MASS SPECTROMETRY REVIEWS, Issue 4 2007
Otilia Mó
Abstract In this review, we present a general overview on the studies carried out on Ni+- - and Ni2+ -containing systems in the gas phase since 1996. We have focused our attention in the determination of binding energies in parallel with an analysis of the structure and bonding of the complexes formed by the interaction of Ni+ with one ligand, or in clusters where this metal ion binds several identical or different ligands. Solvation of Ni2+ by different ligands is also discussed, together with the theoretical information available of doubly charged Ni-containing species. The final section of this review is devoted to an analysis of the gas-phase uni- and bimolecular reactivity of Ni+ and Ni2+ complexes. © 2007 Wiley Periodicals, Inc., Mass Spectrom. Rev. [source]


The structure and function of auditory chordotonal organs in insects

MICROSCOPY RESEARCH AND TECHNIQUE, Issue 6 2004
Jayne E. Yack
Abstract Insects are capable of detecting a broad range of acoustic signals transmitted through air, water, or solids. Auditory sensory organs are morphologically diverse with respect to their body location, accessory structures, and number of sensilla, but remarkably uniform in that most are innervated by chordotonal organs. Chordotonal organs are structurally complex Type I mechanoreceptors that are distributed throughout the insect body and function to detect a wide range of mechanical stimuli, from gross motor movements to air-borne sounds. At present, little is known about how chordotonal organs in general function to convert mechanical stimuli to nerve impulses, and our limited understanding of this process represents one of the major challenges to the study of insect auditory systems today. This report reviews the literature on chordotonal organs innervating insect ears, with the broad intention of uncovering some common structural specializations of peripheral auditory systems, and identifying new avenues for research. A general overview of chordotonal organ ultrastructure is presented, followed by a summary of the current theories on mechanical coupling and transduction in monodynal, mononematic, Type 1 scolopidia, which characteristically innervate insect ears. Auditory organs of different insect taxa are reviewed, focusing primarily on tympanal organs, and with some consideration to Johnston's and subgenual organs. It is widely accepted that insect hearing organs evolved from pre-existing proprioceptive chordotonal organs. In addition to certain non-neural adaptations for hearing, such as tracheal expansion and cuticular thinning, the chordotonal organs themselves may have intrinsic specializations for sound reception and transduction, and these are discussed. In the future, an integrated approach, using traditional anatomical and physiological techniques in combination with new methodologies in immunohistochemistry, genetics, and biophysics, will assist in refining hypotheses on how chordotonal organs function, and, ultimately, lead to new insights into the peripheral mechanisms underlying hearing in insects. Microsc. Res. Tech. 63:315,337, 2004. © 2004 Wiley-Liss, Inc. [source]


The properties of the stellar populations in ULIRGs , I. Sample, data and spectral synthesis modelling

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 3 2009
J. Rodríguez Zaurín
ABSTRACT We present deep long-slit optical spectra for a sample of 36 ultraluminous infrared galaxies (ULIRGs), taken with the William Herschel Telescope on La Palma with the aim of investigating the star formation histories and testing evolutionary scenarios for such objects. Here we present the sample, the analysis techniques and a general overview of the properties of the stellar populations; a more detailed discussion will be presented in a forthcoming paper. Spectral synthesis modelling has been used in order to estimate the ages of the stellar populations found in the diffuse light sampled by the spectra in both the nuclear and extended regions of the target galaxies. We find that adequate fits can be obtained using combinations of young stellar populations (YSPs; tYSP, 2 Gyr), with ages divided into two groups: very young stellar populations (VYSPs; tVYSP, 100 Myr) and intermediate-young stellar populations (IYSPs; 0.1 < tIYSP, 2 Gyr). Our results show that YSPs are present at all locations of the galaxies covered by our slit positions, with the exception of the northern nuclear region of the ULIRG IRAS 23327+2913. Furthermore, VYSPs are present in at least 85 per cent of the 133 extraction apertures used for this study, being more significant in the nuclear regions of the galaxies. Old stellar populations (OSPs; tOSP > 2 Gyr) do not make a major contribution to the optical light in the majority of the apertures extracted. In fact they are essential for fitting the spectra in only 5 per cent (seven) of the extracted apertures. The estimated total masses for the YSPs (VYSPs + IYSPs) are in the range 0.18 × 1010,MYSP, 50 × 1010 M,. We have also estimated the bolometric luminosities associated with the stellar populations detected at optical wavelengths, finding that they fall in the range 0.07 × 1012 < Lbol < 2.2 × 1012 L,. In addition, we find that reddening is significant at all locations in the galaxies. This result emphasizes the importance of accounting for reddening effects when modelling the stellar populations of star-forming galaxies. [source]


Modeling of ZnO nanorods for evanescent field optical sensors

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 10 2007
Sandra Börner
Abstract The optical wave guiding properties of ZnO nanorods are simulated and studied in detail using a block-iterative frequency-domain method and the results of a finite difference method as reference data. The simulations are performed for different wavelengths in the infrared spectral region that are related to specific gas absorption lines. Here both single ZnO nanorods and nanorod arrays with varying period lengths are investigated. The evanescent field distributions and penetration depths into the surrounding media are analyzed and compared as a function of wavelength and rod diameter. Our results give a general overview on the size range where ZnO nanorods may be used for evanescent field interaction based sensors for the detection of gas molecules like CO, CO2 or O2. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


Review of electronic and optical properties of semiconducting ,-conjugated polymers: applications in optoelectronics

POLYMER INTERNATIONAL, Issue 10 2004
André Moliton
Abstract A general overview of the optoelectronic properties of ,-conjugated polymers is presented. Two types of polymer are discerned: interchangeable structures of the same energy (degenerate), such as polyacetylene; and non-degenerate polymers, such as poly(para -phenylene). The band structures of degenerate and non-degenerate polymers are related to their conductivities in doped and non-doped states. In both cases, disorder and impurities play an important role in conductivity. Polarons, bipolarons and excitons are detailed with respect to doping and charge transfers. Given the fibrillic nature of these materials, the variable range hopping (VRH) law for semiconducting polymers is modified to account for metallic behaviours. Optoelectronic properties,electroluminescence and photovoltaic activity,are explained in terms of HOMO and LUMO bands, polaron-exciton and charge movement over one or more molecules. The properties of H- or J-type aggregates and their effects on transitions are related to target applications. Device structures of polymer light-emitting diodes are explicitly linked to optimising polaron recombinations and overall quantum efficiencies. The particularly promising use of ,-conjugated polymers in photovoltaic devices is discussed. Copyright © 2004 Society of Chemical Industry [source]


Epidemiology: Theory, study design, and planning for education

THE JOURNAL OF CONTINUING EDUCATION IN THE HEALTH PROFESSIONS, Issue 3 2000
PhD Assistant Professor, Shelley A. Harris MSc
Abstract Many health professionals have received formal training in epidemiology; however, much of it has been limited to introductory courses at the undergraduate level. Further, continuing education for health professionals has focused historically on substantive rather than methodologic issues in epidemiology. A methodologic focus is recommended to improve continuing education for the health of the public. It is crucial to equip educators and health professionals with the necessary tools or resources to understand study design, conduct research, analyze and interpret data, and critically evaluate published research. Thus, in this article, a general overview of epidemiologic study design and some of the most common methodologic issues are presented. Issues such as confounding, effect modification, measurement error, and power and sample size are highlighted. A broader recognition of these issues by educators and health professionals may ultimately help to improve public health by facilitating effective educational interventions, proper study design, analysis, interpretation, and application of epidemiologic research. [source]


ORIGINAL ARTICLES: Definitions/Epidemiology/Risk Factors for Sexual Dysfunction

THE JOURNAL OF SEXUAL MEDICINE, Issue 4pt2 2010
Ronald W. Lewis MD
ABSTRACT Introduction., Accurate estimates of prevalence/incidence are important in understanding the true burden of male and female sexual dysfunction and in identifying risk factors for prevention efforts. This is the summary of the report by the International Consultation Committee for Sexual Medicine on Definitions/Epidemiology/Risk Factors for Sexual Dysfunction. Aim., The main aim of this article is to provide a general overview of the definitions of sexual dysfunction for men and women, the incidence and prevalence rates, and a description of the risk factors identified in large population-based studies. Methods., Literature regarding definitions, descriptive and analytical epidemiology of sexual dysfunction in men and women were selected using evidence-based criteria. For descriptive epidemiological studies, a Prins score of 10 or higher was utilized to identify population-based studies with adequately stringent criteria. This report represents the opinions of eight experts from five countries developed in a consensus process and encompassing a detailed literature review over a 2-year period. Main Outcome Measures., The study aims to provide state-of-the-art prevalence and incidence rates reported for each dysfunction and stratified by age and gender. Expert opinion was based on the grading of evidence-based medical literature, widespread internal committee discussion, public presentation, and debate. Results., A wealth of information is presented on erectile dysfunction, its development through time, and its correlates. The field is still in need of more epidemiological studies on the other men's sexual dysfunction and on all women's sexual dysfunctions. Conclusions., A review of the currently available evidence from epidemiological studies is provided. Lewis RW, Fugl-Meyer KS, Corona G, Hayes RD, Laumann EO, Moreira ED Jr., Rellini AH, and Segraves T. Definitions/Epidemiology/Risk Factors for Sexual Dysfunction. J Sex Med 2010;7:1598,1607. [source]


Quality in virtual education environments

BRITISH JOURNAL OF EDUCATIONAL TECHNOLOGY, Issue 1 2004
Elena Barbera
The emergence of the Internet has changed the way we teach and learn. This paper provides a general overview of the state of the quality of virtual education environments. First of all, some problems with the quality criteria applied in this field and the need to develop quality seals are presented. Likewise, the dimensions and subdimensions of an empirical instrument to improve and assess the quality of online education are examined. This tool has already been applied to several educational contexts; though not definitive, it aims to improve not only specific areas, but also the whole educational approach as a system. [source]


Adsorptive Behandlung VOC-haltiger Abluftströme , Stand der Technik,

CHEMIE-INGENIEUR-TECHNIK (CIT), Issue 11 2004
D. Bathen PD, Dr.-Ing.
Abstract Um den Stand der Technik bei der adsorptiven Behandlung VOC-haltiger Ströme zu ermitteln, wurden 247 Anlagen analysiert, die in den Jahren 1986 , 2003 gebaut wurden. Insgesamt zeigt diese Analyse, dass nur fünf Kombinationen aus Verfahren und Bautyp im Gebiet der VOC-Behandlung breite Anwendung finden. Es handelt sich um Wechseladsorber, PSA-Festbettadsorber, TSA-Dampf-regenerierte Festbettadsorber, TSA-Abgas-regenerierte Festbettadsorber und TSA-Rotoradsorber. Aufbauend auf diesen Ergebnissen wird anhand von Beispielen aus der Industrie erläutert, welche Stärken und Schwächen die einzelnen Varianten haben und warum in welchen Bereichen welche Adsorbertypen eingesetzt werden. VOC Adsorption Technology , State of the Art This review gives a general overview of the state of the art in VOC adsorption technology. An analysis of 247 plants built between 1986 and 2003 shows that only five combinations of desorption process and adsorber design are widely used in industry. Besides non-regenerated fixed-bed-adsorbers these are PSA-fixed-bed-, TSA-fixed-bed- (steam), TSA-fixed-bed- (purge gas) and TSA-rotating-disc-adsorbers. Moving-bed adsorbers can be found only in specific niches. In the second part of the article advantages as well as disadvantages of each technology are discussed based on typical examples from industry. These properties lead to specific limitations of each technology in industrial applications, which are visualized in a matrix plot. [source]


Small-Molecule Inhibitors of the Hedgehog Signaling Pathway as Cancer Therapeutics

CHEMMEDCHEM, Issue 4 2010
Stefan Peukert Dr.
Abstract Inhibitors of the Hedgehog (Hh) molecular signaling pathway have emerged in recent years as a promising new class of potential therapeutics for cancer treatment. Numerous drug discovery efforts have resulted in the identification of a wide variety of small molecules that target different members of this pathway, including Smoothened (Smo), Sonic hedgehog protein (Shh), and Gli1. Several Smo inhibitors have now entered human clinical trials, and successful proof-of-concept studies have been carried out in patients with defined genetic mutations in the Hh pathway. This review provides a general overview of three main topics in this rapidly expanding area: 1),the various types of biological assays and in,vivo models that have been employed for the identification and optimization of Hh pathway inhibitors; 2),Smo inhibitors reported to date, including recent clinical results where available; and 3),efforts toward the identification and characterization of inhibitors of other members of the Hh pathway. [source]


From behind dikes and dunes: communities that care in the Netherlands

CHILDREN & SOCIETY, Issue 2 2005
Harrie B. Jonkman
This paper will provide a general overview of the implementation of the Communities that Care (CtC) programme in the Netherlands. It outlines the socio-historical development of the initiative and considers the rationale and starting point for the Dutch experiment and the tools used in the process. Attention will also be paid to the implementation of CtC and some of the problems met in trying to introduce the CtC scheme. The final part of this paper will consider the main outcomes of the first (process) evaluation of the experiment. [source]