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Kinds of Prerequisite Selected AbstractsEPISTEMOLOGICAL CONSIDERATIONS ON NEUROIMAGING , A CRUCIAL PREREQUISITE FOR NEUROETHICSBIOETHICS, Issue 6 2009CHRISTIAN G. HUBER ABSTRACT Purpose: Whereas ethical considerations on imaging techniques and interpretations of neuroimaging results flourish, there is not much work on their preconditions. In this paper, therefore, we discuss epistemological considerations on neuroimaging and their implications for neuroethics. Results: Neuroimaging uses indirect methods to generate data about surrogate parameters for mental processes, and there are many determinants influencing the results, including current hypotheses and the state of knowledge. This leads to an interdependence between hypotheses and data. Additionally, different levels of description are involved, especially when experiments are designed to answer questions pertaining to broad concepts like the self, empathy or moral intentions. Interdisciplinary theoretical frameworks are needed to integrate findings from the life sciences and the humanities and to translate between them. While these epistemological issues are not specific for neuroimaging, there are some reasons why they are of special importance in this context: Due to their inferential proximity, ,neuro-images' seem to be self-evident, suggesting directness of observation and objectivity. This has to be critically discussed to prevent overinterpretation. Additionally, there is a high level of attention to neuroimaging, leading to a high frequency of presentation of neuroimaging data and making the critical examination of their epistemological properties even more pressing. Conclusions: Epistemological considerations are an important prerequisite for neuroethics. The presentation and communication of the results of neuroimaging studies, the potential generation of new phenomena and new ,dysfunctions' through neuroimaging, and the influence on central concepts at the foundations of ethics will be important future topics for this discipline. [source] Is Self-Determined Functioning a Universal Prerequisite for Motive,Goal Congruence?JOURNAL OF PERSONALITY, Issue 2 2010Examining the Domain of Achievement in Three Cultures ABSTRACT Research has shown that capacity for accessing implicit motives promotes congruence between the implicit and the explicit motivational system: Individuals able to test a conscious goal for its fit with their implicit motivation commit themselves more fully to self-congruent goals. However, it has not yet been shown whether this is a universal phenomenon or limited to Euro-American cultures in which individual needs are less strictly constrained by the social environment than in other cultural contexts. Thus, the present study examined whether self-determination interacts with the implicit achievement motive to predict how much importance individuals from Cameroon, Germany, and Hong Kong ascribe to achievement goals. Moreover, the importance ascribed to goals should indirectly predict life satisfaction via success in goal realization. Results showed that the associations described above are valid in all three cultural groups and are discussed in terms of their implications for the universal processes characterizing motivation. [source] Soil- and plant-based nitrogen-fertilizer recommendations in arable farmingJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 4 2005Hans-Werner Olfs Abstract Under- as well as overfertilization with nitrogen (N) will result in economic loss for the farmer due to reduced yields and quality of the products. Also from an ecological perspective, it is important that the grower makes the correct decision on how much and when to apply N for a certain crop to minimize impacts on the environment. To aggravate the situation, N is a substance that is present in many compartments in different forms (nitrate, ammonium, organic N, etc.) in the soil-plant environment and takes part in various processes (e.g., mineralization, immobilization, leaching, denitrification, etc.). Today, many N-recommendation systems are mainly based on yield expectation. However, yields are not stable from year to year for a given field. Also the processes that determine the N supply from other sources than fertilizer are not predictable at the start of the growing season. Different methodological approaches are reviewed that have been introduced to improve N-fertilizer recommendations for arable crops. Many soil-based methods have been developed to measure soil mineral N (SMN) that is available for plants at a given sampling date. Soil sampling at the start of the growing period and analyzing for the amount of NO -N (and NH -N) is a widespread approach in Europe and North America. Based on data from field calibrations, the SMN pool is filled up with fertilizer N to a recommended amount. Depending on pre-crop, use of organic manure, or soil characteristics, the recommendation might be modified (±10,50,kg N ha,1). Another set of soil methods has been established to estimate the amount of N that is mineralized from soil organic matter, plant residues, and/or organic manure. From the huge range of methods proposed so far, simple mild extraction procedures have gained most interest, but introduction into practical recommendation schemes has been rather limited. Plant-analytical procedures cover the whole range from quantitative laboratory analysis to semiquantitative "quick" tests carried out in the field. The main idea is that the plant itself is the best indicator for the N supply from any source within the growth period. In-field methods like the nitrate plant sap/petiole test and chlorophyll measurements with hand-held devices or via remote sensing are regarded as most promising, because with these methods an adequate adjustment of the N-fertilizer application strategy within the season is feasible. Prerequisite is a fertilization strategy that is based on several N applications and not on a one-go approach. Boden- und Pflanzenanalyse zur Stickstoff-Düngebedarfsprognose in Ackerkulturen Unter- und Überdüngung mit N führen zu deutlichen ökonomischen Verlusten für Landwirte, da sowohl der Ertrag als auch die Qualität der Erzeugnisse vermindert werden. Auch aus ökologischer Sicht ist die richtige Entscheidung des Anbauers über Höhe und Zeitpunkt der N-Düngung von Bedeutung, um die Auswirkungen auf die Umwelt so gering wie möglich zu halten. Erschwerend kommt hinzu, dass N in sehr vielen Umweltkompartimenten in verschiedenen Bindungsformen (Nitrat, Ammonium, organisch gebundener N) vorkommt und dass N in verschiedenste Umsetzungsprozesse involviert ist (Mineralisation, Immobilisation, Auswaschung, Denitrifikation). Auch heutzutage orientieren sich viele Systeme, die zur N-Düngebedarfsprognose eingesetzt werden, im Wesentlichen an der Ertragserwartung. Dabei ist jedoch zu bedenken, dass weder der Ertrag als von Jahr zu Jahr stabil angesehen werden kann, noch dass die Prozesse, die das bodenbürtige N-Angebot bestimmen, zu Beginn der Vegetationsperiode hinreichend gut vorausgesagt werden können. Daher werden im Folgenden verschiedene methodische Ansätze erläutert, die zur Verbesserung der N-Düngebedarfsprognose für Ackerkulturen geeignet erscheinen. Viele Bodenanalyse-Methoden zielen darauf ab, den mineralischen N-Vorrat des Bodens, der an einem bestimmten Beprobungstermin als pflanzenverfügbarer N vorliegt, zu erfassen. Die Bodenprobeentnahme zu Beginn der Vegetationsperiode und die Bestimmung der Menge an Nitrat (und Ammonium) ist ein in Europa und Nord-Amerika weitverbreiteter Ansatz. Anhand der Daten aus Kalibrierversuchen kann dann abgeleitet werden, wie viel Dünger-N zum Auffüllen des N-Vorrats eingesetzt werden soll. In Abhängigkeit von Vorfrucht, Einsatz von Wirtschaftsdüngern oder weiteren Bodeneigenschaften kann diese Empfehlung modifiziert werden (± 10 bis 50,kg N ha,1). Weitere Bodenuntersuchungsmethoden wurden entwickelt, um die Menge des während der Vegetationszeit aus der organischen Bodensubstanz, aus Ernteresten und/oder aus Wirtschaftsdüngern mineralisierten N zu bestimmen. Obwohl aus der Vielzahl der vorgeschlagenen Methoden einfache "milde" Extraktionsverfahren eine gewisse Bedeutung erlangt haben, werden diese in der Praxis bei der Ermittlung des N-Düngebedarfs als zusätzliche Information nur selten berücksichtigt. Verfahren der Pflanzenanalyse umfassen einen weiten Bereich von quantitativen Laboranalysen bis zu halbquantitativen Schnelltests, die direkt auf dem Acker eingesetzt werden können. Die wesentliche Idee beim Einsatz der Pflanzenanalyse ist die Vorstellung, dass die Pflanze an sich der beste Indikator ist, die N-Verfügbarkeit aus den verschiedenen Quellen gewissermaßen kumulativ innerhalb der Wachstumszeit anzuzeigen. Methoden, die auf dem Acker eingesetzt werden können, wie z.,B. der Nitrat-Pflanzensaft- (oder Blattstiel-)Test sowie die Chlorophyll-Messung mit Handgeräten oder berührungslose Messverfahren haben den klaren Vorteil, dass sie eine schnelle Anpassung der N-Düngestrategie während der Vegetation ermöglichen. Voraussetzung dazu ist allerdings, dass die N-Düngestrategie nicht auf einer Einmal-Applikation beruht, sondern dass die N-Düngermenge auf mehrere Teilgaben verteilt wird. [source] MAMPs and MIMPs: proposed classifications for inducers of innate immunityMOLECULAR MICROBIOLOGY, Issue 6 2006David Mackey Summary Plants encode a sophisticated innate immune system. Resistance against potential pathogens often relies on active responses. Prerequisite to the induction of defences is recognition of the pathogenic threat. Significant advances have been made in our understanding of the non-self molecules that are recognized by plants and the means by which plants perceive them. Established terms describing these recognition events, including microbe-associated molecular pattern (MAMP), MAMP-receptor, effector, and resistance (R) protein, need clarification to represent our current knowledge adequately. In this review we propose criteria to classify inducers of plant defence as either MAMPs or microbe-induced molecular patterns (MIMPs). We refine the definition of MAMP to mean a molecular sequence or structure in ANY pathogen-derived molecule that is perceived via direct interaction with a host defence receptor. MIMPs are modifications of host-derived molecules that are induced by an intrinsic activity of a pathogen-derived effector and are perceived by a host defence receptor. MAMP-receptors have previously been classified separately from R-proteins as a discrete class of surveillance molecules. However, MAMP-receptors and R-proteins cannot be distinguished on the basis of their protein structures or their induced responses. We propose that MAMP-receptors and MIMP-receptors are each a subset of R-proteins. Although our review is based on examples from plant pathogens and plants, the principles discussed might prove applicable to other organisms. [source] Prerequisites for recombinant factor VIIa-induced thrombin generation in plasmas deficient in factors VIII, IX or XIJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 1 2006T. LIVNAT Summary.,Background:,Recombinant factor VIIa (rFVIIa) used for the treatment of hemophilia A or B patients with an inhibitor is hemostatically effective because it induces thrombin generation (TG), despite grossly impaired FVIII- and FIX-dependent amplification of FX activation. Tissue factor (TF) and or activated platelets were shown to be essential for the rFVIIa activity. Objective: To evaluate the relative effects of TF and phospholipids on rFVIIa-induced TG in FVIII-, FIX- and FXI-deficient plasmas. Methods: Phospholipids had an independent effect that was augmented by TF. The contribution of blood-borne TF in FVIII-, FIX- and FXI-deficient plasma to rFVIIa-induced TG was demonstrated by removing microparticles and use of anti-TF antibodies. Results: At increasing concentrations of rFVIIa, the dependence of rFVIIa-induced TG on TF declined, but the presence of phospholipids was essential. rFVIIa was also shown to activate purified FIX and FX in the presence of phospholipids and absence of TF. rFVIIa-induced TG was dramatically augmented in FVIII- or FIX-deficient plasma in which the level of FVIII or FIX was increased to 1 or 2 U dL,1. Conclusions: The data indicate that rFVIIa-induced TG is affected by TF, phospholipids, rFVIIa concentration, and the presence of FVIII and FIX. [source] Public Sector Banks in India: Rationale and Prerequisites for reformANNALS OF PUBLIC AND COOPERATIVE ECONOMICS, Issue 1 2002T.G. Arun This paper contributes to the debate on public sector banks by suggesting several rationales for government ownership of banks in India. The paper then proceeds to argue that due to high economic costs, the current public sector banking system is unsustainable. Although a policy of wider private ownership was introduced in the 1990s, it is suggested that there are several prerequisites to be met before such a reform can be more fully implemented. It is argued that these prerequisites arise from the rationales for government ownership, and they include a credible bank regulatory regime, and government promotion of co-operative banks and credit unions. [source] Parameters for Successful Implant Integration Revisited Part I: Immediate Loading Considered in Light of the Original Prerequisites for OsseointegrationCLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 2010FACD, Oded Bahat BDS ABSTRACT Purpose: With the increasing popularity and publication of loading implants at the time of placement, including at time of dental extraction and simultaneous with reconstructive procedures, the objective was to evaluate known variables identified for a traditional unloaded healing period and determine the applicability of these variables to immediate loading. Materials: A total of 124 published reports available as of January 2008 that contained information about loading from the time of surgery up to 3 months postsurgically were examined in light of published variables affecting osseointegration based on a 2 stage surgical approach. Methods: The articles were examined to differentiate between immediate loading (within the initial 48 hours) and early/delayed loading of implants. Success or survival criteria were noted, and where reasons for failure were available, categorized according to six variables considered as determinants for maintaining a long-term bone-to-implant contact. Results: Approximately 60 of the 124 reports described immediately loading implants within 48 with single-tooth, partial, and full-arch restorations, as well as implant overdentures. The implant success or survival rates ranged from 70.8% to 100%. Most studies considered implant survival to be the only criterion for success. Conclusions: Of six parameters identified in 1981 as influencing osseointegration, two parameters (the status of the bone/implant site and implant loading conditions) appear to have diagnostic implications, whereas three (implant design, surgical technique, and implant finish) may affect immediate loading positively or adversely. [source] Blood flow rate measurements with indicator techniques revisitedCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 6 2009Per Sejrsen Summary In view of the emerging role, disturbances in regional blood flow rate seem to play in the pathogenesis of the metabolic syndrome; we review the concepts of the classical indicator dilution and washout techniques used for determinations of regional blood flow rate. Prerequisites, assumptions, necessary precautions for the application of these experimental techniques are emphasized. Special attention has been carried out to elucidate the consequence of a choice of indicators having a large distribution volume in the tissues. [source] Time-Adaptive Lines for the Interactive Visualization of Unsteady Flow Data SetsCOMPUTER GRAPHICS FORUM, Issue 8 2009N. Cuntz I.3.3 [Computer Graphics]: Line and Curve Generation; I.3.1 [Computer Graphics]: Parallel Processing Abstract The quest for the ideal flow visualization reveals two major challenges: interactivity and accuracy. Interactivity stands for explorative capabilities and real-time control. Accuracy is a prerequisite for every professional visualization in order to provide a reliable base for analysis of a data set. Geometric flow visualization has a long tradition and comes in very different flavors. Among these, stream, path and streak lines are known to be very useful for both 2D and 3D flows. Despite their importance in practice, appropriate algorithms suited for contemporary hardware are rare. In particular, the adaptive construction of the different line types is not sufficiently studied. This study provides a profound representation and discussion of stream, path and streak lines. Two algorithms are proposed for efficiently and accurately generating these lines using modern graphics hardware. Each includes a scheme for adaptive time-stepping. The adaptivity for stream and path lines is achieved through a new processing idea we call ,selective transform feedback'. The adaptivity for streak lines combines adaptive time-stepping and a geometric refinement of the curve itself. Our visualization is applied, among others, to a data set representing a simulated typhoon. The storage as a set of 3D textures requires special attention. Both algorithms explicitly support this storage, as well as the use of precomputed adaptivity information. [source] Structural information from quadrupolar nuclei in solid state NMRCONCEPTS IN MAGNETIC RESONANCE, Issue 3 2006Sharon E. Ashbrook Abstract Solid-state NMR has become the method of choice for determining details of molecular-level structure in heterogeneous systems. Though spin-1/2 nuclei still form the core of most such studies, quadrupolar nuclei are increasingly being used. This review assesses what is currently possible, from achieving high-resolution spectra for quadrupolar nuclei (a prerequisite for most structure determination work), to forming correlation spectra which give qualitative details of spatial proximity of nuclei and the determination of internuclear distances, between quadrupolar spins and quadrupolar and spin-1/2 nuclei. Examples are given of each method discussed, and the advantages and disadvantages of the various experiments for different possible applications are assessed. © 2006 Wiley Periodicals, Inc. Concepts Magn Reson Part A 28A: 183,248, 2006. [source] Drug-elicited systemic allergic (contact) dermatitis , update and possible pathomechanismsCONTACT DERMATITIS, Issue 4 2008Jacob Pontoppidan Thyssen An allergic dermatitis reaction may develop after systemic exposure to a hapten that reaches the skin through haematogenous transport. This condition can be observed with and without previous cutaneous sensitization to the hapten but has traditionally been described following topical exposure. A heterogeneous clinical picture, in combination with limited insight to its pathomechanisms, makes such systemic reactions an area in need of further study. This article summarizes knowledge about systemic dermatitis elicited by drugs, with a special emphasis on possible pathomechanisms. A list of putative pathomechanisms is offered for future research. Literature was examined using PubMed,MEDLINE, EMBASE, Biosis, and Science Citation Index. Based on the literature, it is likely that humoral type 3, delayed-type hypersensitivity, and drug-driven (i.e. p-i concept) reactions are involved. As commonly used terms may be misleading because skin contact is not a prerequisite, we suggest that the term ,systemic allergic dermatitis' should be used in the future. [source] The epidemiology of contact allergy in the general population , prevalence and main findingsCONTACT DERMATITIS, Issue 5 2007Jacob Pontoppidan Thyssen A substantial number of studies have investigated the prevalence of contact allergy in the general population and in unselected subgroups of the general population. The aim of this review was to determine a median prevalence and summarize the main findings from studies on contact allergy in the general population. Published research mainly originates from North America and Western Europe. The median prevalence of contact allergy to at least 1 allergen was 21.2% (range 12.5,40.6%), and the weighted average prevalence was 19.5%, based on data collected on all age groups and all countries between 1966 and 2007. The most prevalent contact allergens were nickel, thimerosal, and fragrance mix. The median nickel allergy prevalence was 8.6% (range 0.7,27.8%) and demonstrates that nickel was an important cause of contact allergy in the general population and that it was widespread in both men and women. Numerous studies demonstrated that pierced ears were a significant risk factor for nickel allergy. Nickel was a risk factor for hand eczema in women. Finally, heavy smoking was associated with contact allergy, mostly in women. Population-based epidemiological studies are considered a prerequisite in the surveillance of national and international contact allergy epidemics. [source] Guidelines for the descriptive presentation and statistical analysis of contact allergy dataCONTACT DERMATITIS, Issue 2 2004Wolfgang Uter The present guidelines aim to support clinical researchers in adequately presenting data on contact allergy, and to use statistical tests appropriate for their data. A description of the mode of selection of patients, and of their relevant demographic details, is an essential prerequisite for the correct interpretation of study results. Proportions and rates, if regarded as estimate of these parameters of a target populations, should normally be supplemented with confidence intervals to address precision. Concordance, i.e., agreement between two ratings in a dependent sample, must be quantified with a chance-corrected measure such as Cohen's kappa coefficient. If the diagnostic quality of an outcome is being assessed, standard measures like sensitivity and specificity, as well as the prevalence-dependent positive and negative predictive values should be calculated. Often, contact allergy to a certain substance depends on several factors. In this situation, depending on the research question, techniques like stratification, standardization or multifactorial analysis should be employed. With increasing complexity of statistical description and analysis, consulting with a biostatistician is often mandatory. [source] AMP-activated protein kinase in the regulation of hepatic energy metabolism: from physiology to therapeutic perspectivesACTA PHYSIOLOGICA, Issue 1 2009B. Viollet Abstract As the liver is central in the maintenance of glucose homeostasis and energy storage, knowledge of the physiology as well as physiopathology of hepatic energy metabolism is a prerequisite to our understanding of whole-body metabolism. Hepatic fuel metabolism changes considerably depending on physiological circumstances (fed vs. fasted state). In consequence, hepatic carbohydrate, lipid and protein synthesis/utilization are tightly regulated according to needs. Fatty liver and hepatic insulin resistance (both frequently associated with the metabolic syndrome) or increased hepatic glucose production (as observed in type 2 diabetes) resulted from alterations in substrates oxidation/storage balance in the liver. Because AMP-activated protein kinase (AMPK) is considered as a cellular energy sensor, it is important to gain understanding of the mechanism by which hepatic AMPK coordinates hepatic energy metabolism. AMPK has been implicated as a key regulator of physiological energy dynamics by limiting anabolic pathways (to prevent further ATP consumption) and by facilitating catabolic pathways (to increase ATP generation). Activation of hepatic AMPK leads to increased fatty acid oxidation and simultaneously inhibition of hepatic lipogenesis, cholesterol synthesis and glucose production. In addition to a short-term effect on specific enzymes, AMPK also modulates the transcription of genes involved in lipogenesis and mitochondrial biogenesis. The identification of AMPK targets in hepatic metabolism should be useful in developing treatments to reverse metabolic abnormalities of type 2 diabetes and the metabolic syndrome. [source] Corporate Governance of Banks in Developing Economies: concepts and issuesCORPORATE GOVERNANCE, Issue 3 2004T. G. Arun This paper discusses the corporate governance of banking institutions in developing economies. This is an important issue given the essential role that banks play in the financial systems of developing economies and the widespread banking reforms that these economies have implemented. Based on a theoretical discussion of the corporate governance of banks, we suggest that banking reforms can only be fully implemented once a prudential regulatory system is in place. An integral part of banking reforms in developing economies is the privatisation of banks. We suggest that corporate governance reforms may be a prerequisite for the successful divestiture of government ownership. Furthermore, we also suggest that the increased competition resulting from the entrance of foreign banks may improve the corporate governance of developing-economy banks. [source] Organizing for Continuous Innovation: On the Sustainability of Ambidextrous OrganizationsCREATIVITY AND INNOVATION MANAGEMENT, Issue 3 2005Bart Van Looy Organizing for innovation does not present itself as a straightforward exercise. The complexities entailed when implementing an innovation strategy can be related directly to the multitude of objectives it comprises. Recently, several scholars have advanced the notions of semi- or quasi-structures and ambidextrous organizations to handle these multiple requirements. These organizational forms imply the simultaneous presence of different activities, exhibiting differences in technology and market maturation. As a consequence, financial returns will reflect this diversified resource allocation pattern. Moreover, as higher levels of complexity are being introduced; ambidextrous organizations will encounter additional, organizational, costs. Compared to organizations that focus on the most profitable part of the portfolio, ambidextrous organizations , ceteris paribus , tend to be inferior in terms of financial returns. Within this contribution we explore under which conditions ambidextrous organizations can outperform focused firms; considered a prerequisite for their sustainability. In order to do so, we develop an analytical framework depicting the differential value dynamics, focused and ambidextrous firms can enact. Our findings reveal the relevancy of adopting extended time frames as well as introducing interface management practices aimed at cross-fertilization. Finally, the synergetic potential of (underlying) technologies comes to the forefront as necessary in order for ambidextrous organizations to become sustainable. [source] Rapid crystal growth without inherent supersaturation induced by nanoscale fluid flows?CRYSTAL RESEARCH AND TECHNOLOGY, Issue 1 2006M. J. Jones Abstract Crystal growth is a process that only takes place under non-equilibrium conditions and a necessary prerequisite is that the crystal is exposed to a phase that is supersaturated in the material the crystal is composed of, be it a solution, a vapour or a supercooled melt. In industrial mass crystallization the growth rate for a population of crystals (in suspension growth processes [1]) rarely exceeds mean linear velocities of 10 -7 ms -1. Here we present a mass crystallization process which is accompanied by rapid crystal growth several orders of magnitude faster and into a region of solution that is without inherent supersaturation. The material investigated is a solid hydrate that exhibits a solution mediated phase transition to its anhydrous form in the presence of methanol [2]. The phase transition is initiated simply by placing an amount of hydrate crystals into the solvent and is characterized by the rapid emergence of needle-shaped crystals. The needles emanate from the crystal faces of the hydrate crystals and grow into the solution, which is nominally free of the substance to be crystallized. The high growth rate of the crystals, which of the order of up to 10 -4 ms -1 is surprising. Although rapid needle growth has been observed before [3-9], to date a satisfactory explanation for needles growing under the abovementioned conditions is still outstanding. Based upon the topology of the crystals we propose a tentative mechanism for this phenomenon capable of explaining the unusually rapid growth and highlight those questions that need addressing in order to verify this mechanism. X-ray powder diffraction is used to characterize the crystal phase of the needles; confocal fluorescence microscopy reveals that the needles are hollow. The width of these needles is between 0.5 and 5 ,m, their length appears to be limited only by the amount of hydrate available for their formation. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] How adhesion, migration, and cytoplasmic calcium transients influence interleukin-1, mRNA stabilization in human monocytesCYTOSKELETON, Issue 3 2004P. Pomorski Abstract We investigated the mechanisms by which primary human monocyte migration and the production of important cytokines are co-regulated. Motile monocytes underwent cyclic morphologic and adhesive changes that were associated with intracellular free calcium changes; in such cells, cytokine transcripts were unstable and translationally repressed. Agents that activate monocytes, including lipopolysacharrides (LPS), cytomegalovirus (CMV), and tumor necrosis factor (TNF,), have been shown to de-repress translation and these agents stabilize adhesion-induced transcripts for IL-l, and IL-8 and markedly diminish cell migration in the presence of autologous serum. LPS suppressed Rho A activity and either this agent or C3 transferase elevated intracellular free calcium, stabilized transcripts, and, in tandem, inhibited cell migration by preventing tail retraction, a prerequisite for cell translocation. These results, therefore, suggest that monocyte activating agents inhibit the RhoA pathway and continuously elevate intracellular calcium leading to a concomitant decrease in monocyte migration and stabilization of cytokine transcripts prior to translation. Cell Motil. Cytoskeleton 57:143,157, 2004. © 2004 Wiley-Liss, Inc. [source] Gadolinium, a mechano-sensitive channel blocker, inhibits osmosis-initiated motility of sea- and freshwater fish sperm, but does not affect human or ascidian sperm motilityCYTOSKELETON, Issue 4 2003Zoltán Krasznai Abstract Exposure to hypo-osmotic or hyperosmotic environment triggers the initiation of fish sperm motility. In this article, we report that calcium and potassium channel blockers do not influence motility of puffer fish sperm but calmodulin antagonists reversibly decrease it, suggesting that calmodulin,Ca2+ interactions are prerequisite for the initiation of sperm motility in this species. Gadolinium (a stretch activated ion channel blocker) decreased the motility of puffer fish sperm from 92 ± 3% to 6 ± 3% and that of carp sperm from 91 ± 7% to 3.5 ± 4.3% in a dose-dependent manner (10,40 ,M). The effect of gadolinium was reversible, suggesting that stretch activated ion channels participate in the initiation of sperm motility of the two species. Gadolinium inhibits changes in the isoelectric point of certain proteins of puffer fish sperm, which occur when sperm motility is initiated in a hypertonic solution. Anisotropy measurements showed that hypo-osmotic treatment, which initiates carp sperm motility, increased membrane fluidity. When hypo-osmotic treatment was given in the presence of gadolinium, the sperm membrane remained as rigid as in quiescent cells, while motility was blocked. By contrast, gadolinium did not influence the motility parameters of Ciona or human sperm. Based on these lines of evidence, we suggest that conformational changes of mechanosensitive membrane proteins are involved in osmolality-dependent but not osmolality-independent sperm. Cell Motil. Cytoskeleton 55:232,243, 2003. © 2003 Wiley-Liss, Inc. [source] Scaling up Participatory Watershed Development in IndiaDEVELOPMENT AND CHANGE, Issue 2 2002Shashi Kolavalli ,Participation' is widely accepted as a prerequisite to successful watershed development in India, but there is no shared understanding of its meaning, nor of how to make it operational. Meaningful participation, in which communities work collectively, help make decisions and share costs, is limited primarily to projects implemented by non-governmental organizations (NGOs). Participation in government projects is more superficial because staff lack the skills and incentive to engage in meaningful participation. Strategies to scale up meaningful participation require a large number of NGOs. However, the number of NGOs with the necessary skills and values is limited, so a realistic strategy must seek to improve the capabilities and incentives of government agencies. Their performance may improve by making them accountable through transparent processes and participatory monitoring and evaluation. NGO-facilitated access to information for communities can potentially change power relations and initiate political processes that make both community leaders and government agencies more accountable to communities. [source] Regulation of oocyte maturation in fishDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 2008Yoshitaka Nagahama A period of oocyte growth is followed by a process called oocyte maturation (the resumption of meiosis) which occurs prior to ovulation and is a prerequisite for successful fertilization. Our studies using fish models have revealed that oocyte maturation is a three-step induction process involving gonadotropin (LH), maturation-inducing hormone (MIH), and maturation-promoting factor (MPF). LH acts on the ovarian follicle layer to produce MIH (17,, 20,-dihydroxy-4-pregnen-3-one, 17,, 20,-DP, in most fishes). The interaction of ovarian thecal and granulosa cell layers (two-cell type model), is required for the synthesis of 17,,20,-DP. The dramatic increase in the capacity of postvitellogenic follicles to produce 17,,20,-DP in response to LH is correlated with decreases in P450c17 (P450c17-I) and P450 aromatase (oP450arom) mRNA and increases in the novel form of P450c17 (P450c17-II) and 20,-hydroxysteroid dehydrogenase (20,-HSD) mRNA. Transcription factors such as Ad4BP/SF-1, Foxl2, and CREB may be involved in the regulation of expression of these steroidogenic enzymes. A distinct family of G-protein-coupled membrane-bound MIH receptors has been shown to mediate non-genomic actions of 17,, 20,-DP. The MIH signal induces the de novo synthesis of cyclin B from the stored mRNA, which activates a preexisting 35 kDa cdc2 kinase via phosphorylation of its threonine 161 by cyclin-dependent kinase activating kinase, thus producing the 34 kDa active cdc2 (active MPF). Upon egg activation, MPF is inactivated by degradation of cyclin B. This process is initiated by the 26S proteasome through the first cut in its NH2 terminus at lysine 57. [source] Functional regeneration of the olfactory bulb requires reconnection to the olfactory nerve in Xenopus larvaeDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 1 2006Jun Yoshino Larvae of the South African clawed frog (Xenopus laevis) can regenerate the telencephalon, which consists of the olfactory bulb and the cerebrum, after it has been partially removed. Some authors have argued that the telencephalon, once removed, must be reconnected to the olfactory nerve in order to regenerate. However, considerable regeneration has been observed before reconnection. Therefore, we have conducted several experiments to learn whether or not reconnection is a prerequisite for regeneration. We found that the olfactory bulb did not regenerate without reconnection, while the cerebrum regenerated by itself. On the other hand, when the brain was reconnected by the olfactory nerve, both the cerebrum and the olfactory bulb regenerated. Morphological and histological investigation showed that the regenerated telencephalon was identical to the intact one in morphology, types and distributions of cells, and connections between neurons. Froglets with a regenerated telencephalon also recovered olfaction, the primary function of the frog telencephalon. These results suggest that the Xenopus larva requires reconnection of the regenerating brain to the olfactory nerve in order to regenerate the olfactory bulb, and thus the regenerated brain functions, in order to process olfactory information. [source] The epidemiology of attention-deficit/hyperactivity disorder (ADHD): A public health viewDEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 3 2002Andrew S. Rowland Abstract Attention-deficit/hyperactivity disorder (ADHD) is the most common neurodevelopmental disorder of childhood. However, basic information about how the prevalence of ADHD varies by race/ethnicity, sex, age, and socio-economic status remains poorly described. One reason is that difficulties in the diagnosis of ADHD have translated into difficulties developing an adequate case definition for epidemiologic studies. Diagnosis depends heavily on parent and teacher reports; no laboratory tests reliably predict ADHD. Prevalence estimates of ADHD are sensitive to who is asked what, and how information is combined. Consequently, recent systematic reviews report ADHD prevalence estimates as wide as 2%,18%. The diagnosis of ADHD is complicated by the frequent occurrence of comorbid conditions such as learning disability, conduct disorder, and anxiety disorder. Symptoms of these conditions may also mimic ADHD. Nevertheless, we suggest that developing an adequate epidemiologic case definition based on current diagnostic criteria is possible and is a prerequisite for further developing the epidemiology of ADHD. The etiology of ADHD is not known but recent studies suggest both a strong genetic link as well as environmental factors such as history of preterm delivery and perhaps, maternal smoking during pregnancy. Children and teenagers with ADHD use health and mental health services more often than their peers and engage in more health threatening behaviors such as smoking, and alcohol and substance abuse. Better methods are needed for monitoring the prevalence and understanding the public health implications of ADHD. Stimulant medication is the treatment of choice for treating ADHD but psychosocial interventions may also be warranted if comordid disorders are present. The treatment of ADHD is controversial because of the high prevalence of medication treatment. Epidemiologic studies could clarify whether the patterns of ADHD diagnosis and treatment in community settings is appropriate. Population-based epidemiologic studies may shed important new light on how we understand ADHD, its natural history, its treatment and its consequences. MRDD Research Reviews 2002;8:162,170. © 2002 Wiley-Liss, Inc. [source] Endothelium-specific Cre recombinase activity in flk-1-Cre transgenic miceDEVELOPMENTAL DYNAMICS, Issue 2 2004Alexander H. Licht Abstract The use of the Cre-loxP recombination system allows the conditional inactivation of genes in mice. The availability of transgenic mice in which the Cre recombinase expression is highly cell type specific is a prerequisite to successfully use this system. We previously have characterized regulatory regions of the mouse flk-1 gene sufficient for endothelial cell-specific expression of the LacZ reporter gene in transgenic mice. These regions were fused to the Cre recombinase gene, and transgenic mouse lines were generated. In the resulting flk-1-Cre transgenic mice, specificity of Cre activity was determined by cross-breeding with the reporter mouse lines Rosa26R or CAG-CAT-LacZ. We examined double-transgenic mice at different stages of embryonic development (E9.5,E16.5) and organs of adult animals by LacZ staining. Strong endothelium-specific staining of most vascular beds was observed in embryos older than E11.5 in one or E13.5 in a second line. In addition, the neovasculature of experimental BFS-1 tumors expressed the transgene. These lines will be valuable for the conditional inactivation of floxed target genes in endothelial cells of the embryonic vascular system. Developmental Dynamics 229:312,318, 2004. © 2004 Wiley-Liss, Inc. [source] T-box gene products are required for mesenchymal induction of epithelial branching in the embryonic mouse lungDEVELOPMENTAL DYNAMICS, Issue 1 2003Judith A. Cebra-Thomas Abstract The regulation of signaling pathways is a prerequisite for coordinating the induction between mesenchymal and epithelial tissues during morphogenesis. Mesenchymal FGF10 is known to be an important paracrine factor regulating the branching morphogenesis of the bronchial epithelium. By using antisense oligonucleotides (AS ODNs) and in vitro culture of embryonic lungs, we demonstrate that the transcription factors Tbx4 and Tbx5 are critical for the expression of mesenchymal FGF10. Treatment of embryonic lung cultures with AS ODNs to Tbx4 and Tbx5 reduces the level of these transcripts, suppresses Fgf10 expression in the mesenchyme, and completely eliminates the formation of new lung branches. If FGF10 is locally replaced in these AS ODN-treated lungs, epithelial branching is restored. These studies provide evidence that the production of branching signals by the lung mesenchyme is mediated by T-box genes. © 2002 Wiley-Liss, Inc. [source] Glutamate drives the touch response through a rostral loop in the spinal cord of zebrafish embryosDEVELOPMENTAL NEUROBIOLOGY, Issue 12 2009Thomas Pietri Abstract Characterizing connectivity in the spinal cord of zebrafish embryos is not only prerequisite to understanding the development of locomotion, but is also necessary for maximizing the potential of genetic studies of circuit formation in this model system. During their first day of development, zebrafish embryos show two simple motor behaviors. First, they coil their trunks spontaneously, and a few hours later they start responding to touch with contralateral coils. These behaviors are contemporaneous until spontaneous coils become infrequent by 30 h. Glutamatergic neurons are distributed throughout the embryonic spinal cord, but their contribution to these early motor behaviors in immature zebrafish is still unclear. We demonstrate that the kinetics of spontaneous coiling and touch-evoked responses show distinct developmental time courses and that the touch response is dependent on AMPA-type glutamate receptor activation. Transection experiments suggest that the circuits required for touch-evoked responses are confined to the spinal cord and that only the most rostral part of the spinal cord is sufficient for triggering the full response. This rostral sensory connection is presumably established via CoPA interneurons, as they project to the rostral spinal cord. Electrophysiological analysis demonstrates that these neurons receive short latency AMPA-type glutamatergic inputs in response to ipsilateral tactile stimuli. We conclude that touch responses in early embryonic zebrafish arise only after glutamatergic synapses connect sensory neurons and interneurons to the contralateral motor network via a rostral loop. This helps define an elementary circuit that is modified by the addition of sensory inputs, resulting in behavioral transformation. © 2009 Wiley Periodicals, Inc. Develop Neurobiol 2009 [source] Polysialic acid controls NCAM-induced differentiation of neuronal precursors into calretinin-positive olfactory bulb interneuronsDEVELOPMENTAL NEUROBIOLOGY, Issue 9 2008Iris Röckle Abstract Understanding the mechanisms that regulate neurogenesis is a prerequisite for brain repair approaches based on neuronal precursor cells. One important regulator of postnatal neurogenesis is polysialic acid (polySia), a post-translational modification of the neural cell adhesion molecule NCAM. In the present study, we investigated the role of polySia in differentiation of neuronal precursors isolated from the subventricular zone of early postnatal mice. Removal of polySia promoted neurite induction and selectively enhanced maturation into a calretinin-positive phenotype. Expression of calbindin and Pax6, indicative for other lineages of olfactory bulb interneurons, were not affected. A decrease in the number of TUNEL-positive cells indicated that cell survival was slightly improved by removing polySia. Time lapse imaging revealed the absence of chain migration and low cell motility, in the presence and absence of polySia. The changes in survival and differentiation, therefore, could be dissected from the well-known function of polySia as a promoter of precursor migration. The differentiation response was mimicked by exposure of cells to soluble or substrate-bound NCAM and prevented by the C3d-peptide, a synthetic ligand blocking NCAM interactions. Moreover, a higher degree of differentiation was observed in cultures from polysialyltransferase-depleted mice and after NCAM exposure of precursors from NCAM-knockout mice demonstrating that the NCAM function is mediated via heterophilic binding partners. In conclusion, these data reveal that polySia controls instructive NCAM signals, which direct the differentiation of subventricular zone-derived precursors towards the calretinin-positive phenotype of olfactory bulb interneurons. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008 [source] Oxidative stress, nitric oxide, and the mechanisms of cell death in Lurcher Purkinje cellsDEVELOPMENTAL NEUROBIOLOGY, Issue 8 2007Rebecca McFarland Abstract Oxidative stress is postulated to play a role in cell death in many neurodegenerative diseases. As a model of neonatal neuronal cell death, we have examined the role of oxidative stress in Purkinje cell death in the heterozygous Lurcher mutant (+/Lc). Lurcher is a gain of function mutation in the ,2 glutamate receptor (GluR,2) that turns the receptor into a leaky membrane channel, resulting in chronic depolarization of +/Lc Purkinje cells starting around the first week of postnatal development. Virtually, all +/Lc Purkinje cells die by the end of the first postnatal month. To investigate the role of oxidative stress in +/Lc Purkinje cell death, we have examined nitric oxide synthase (NOS) activity and the expression of two markers for oxidative stress, nitrotyrosine and manganese super oxide dismutase (MnSOD), in wild type and +/Lc Purkinje cells at P10, P15, and P25. The results show that NOS activity and immunolabeling for nitrotyrosine and MnSOD are increased in +/Lc Purkinje cells. To determine whether peroxynitrite formation is a prerequisite for +/Lc Purkinje cell death, +/Lc mutants were crossed with an ,-nNOS knockout mutant (nNOS,,/,) to reduce the production of NO. Analysis of the double mutants showed that blocking ,-nNOS expression does not rescue +/Lc Purkinje cells. However, we present evidence for sustained NOS activity and nitrotyrosine formation in the GluR,2+/Lc:nNOS,/, double mutant Purkinje cells, which suggests that the failure to rescue GluR,2+/Lc:nNOS,/, Purkinje cells may be explained by the induction of alternative nNOS isoforms. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007. [source] Early detection and treatment of schizophrenia: how early?ACTA PSYCHIATRICA SCANDINAVICA, Issue 2006A. Riecher-Rössler Objective:, Whereas early detection and therapy of schizophrenic psychoses until some time ago concentrated on frank schizophrenia, during the last years some centres have also started to treat patients even before a clear diagnosis could be established. This paper attempts to discuss if and when this is justified in the light of recent research. Method:, Mini review of literature. Results:, The rationale for early detection and treatment of schizophrenia is based on several observations: diagnosis and treatment of schizophrenia are often seriously delayed. Consequences of the disease are severe already in the early undiagnosed phase of the disorder and early treatment seems to improve the course of the disease. It can therefore be stated quite safely that patients should be treated as early as possible. However, the question of how early has not been sufficiently answered up to now. Conclusion:, We are at the moment in an ethical dilemma between either diagnosing and treating this disorder too late or too early. The only way and prerequisite for solving this dilemma is a more reliable identification of individuals at risk and the beginning disease process. [source] Children's understanding of idioms and theory of mind developmentDEVELOPMENTAL SCIENCE, Issue 5 2008Stéphanie Caillies The aim of this study was to test the hypothesis according to which theory of mind competence was a prerequisite to ambiguous idioms understanding. We hypothesized that the child needs to understand that the literal interpretation could be a false world representation, a false belief, and that the speaker's intention is to mean something else, to correctly process idiomatic expressions. Two kinds of ambiguous idioms were of interest: decomposable and nondecomposable expressions (Titone & Connine, 1999). An experiment was designed to assess the figurative developmental changes that occur with theory of mind competence. Five-, 6- and 7-year-old children performed five theory of mind tasks (an appearance,reality task, three false-belief tasks and a second-order false-belief task) and listened to decomposable and nondecomposable idiomatic expressions inserted in context, before performing a multiple choice task. Results indicated that only nondecomposable idiomatic expression was predicted from the theory of mind scores, and particularly from the second-order competences. Results are discussed with respect to theory of mind and verbal competences. [source] | ||||||||||||||||||||||||||||||||||