Existing Knowledge (existing + knowledge)

Distribution by Scientific Domains


Selected Abstracts


Colonization of an island volcano, Long Island, Papua New Guinea, and an emergent island, Motmot, in its caldera lake.

JOURNAL OF BIOGEOGRAPHY, Issue 11-12 2001

Abstract Biogeographical context Long Island, in Vitiaz Strait, is 55 km north of New Guinea, 60 km from Umboi Island and 125 km from New Britain. After its explosive caldera-forming eruption in about 1645, Long is being recolonized by animals and plants. Through renewed volcanic activity in the 1950s a new island emerged from Long's caldera lake, 4 km from the nearest lake shore and was recreated by eruptions in 1968. Long Island thus provides the opportunity to study a nested pair of natural colonization sequences. The geological background, eruptive history, course and results of the seventeenth century eruption, and the geographical features and climate of Long Island are summarized. Existing knowledge of Long's recolonization, confined almost entirely to surveys of its avifauna in 1933 and 1972, is reviewed. The geological history of Motmot is outlined, and published knowledge of its colonization by animals and plants from 1968 to 1988 is summarized. The 1999 expedition and aims An expedition to Long Island and Motmot in 1999 set out to investigate the hitherto little-known flora and present vertebrate fauna of Long Island and to survey the entire flora and fauna of Motmot for comparison with the results of previous surveys. The methods used in the 1999 survey are described, and the papers setting out the results briefly introduced. [source]


Adverse outcome pathways: A conceptual framework to support ecotoxicology research and risk assessment

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2010
Gerald T. Ankley
Abstract Ecological risk assessors face increasing demands to assess more chemicals, with greater speed and accuracy, and to do so using fewer resources and experimental animals. New approaches in biological and computational sciences may be able to generate mechanistic information that could help in meeting these challenges. However, to use mechanistic data to support chemical assessments, there is a need for effective translation of this information into endpoints meaningful to ecological risk,effects on survival, development, and reproduction in individual organisms and, by extension, impacts on populations. Here we discuss a framework designed for this purpose, the adverse outcome pathway (AOP). An AOP is a conceptual construct that portrays existing knowledge concerning the linkage between a direct molecular initiating event and an adverse outcome at a biological level of organization relevant to risk assessment. The practical utility of AOPs for ecological risk assessment of chemicals is illustrated using five case examples. The examples demonstrate how the AOP concept can focus toxicity testing in terms of species and endpoint selection, enhance across-chemical extrapolation, and support prediction of mixture effects. The examples also show how AOPs facilitate use of molecular or biochemical endpoints (sometimes referred to as biomarkers) for forecasting chemical impacts on individuals and populations. In the concluding sections of the paper, we discuss how AOPs can help to guide research that supports chemical risk assessments and advocate for the incorporation of this approach into a broader systems biology framework. Environ. Toxicol. Chem. 2010;29:730,741. © 2009 SETAC [source]


Calcium homeostasis and signaling in yeast cells and cardiac myocytes

FEMS YEAST RESEARCH, Issue 8 2009
Jiangjun Cui
Abstract Calcium ions are the most ubiquitous and versatile signaling molecules in eukaryotic cells. Calcium homeostasis and signaling systems are crucial for both the normal growth of the budding yeast Saccharomyces cerevisiae and the intricate working of the mammalian heart. In this paper, we make a detailed comparison between the calcium homeostasis/signaling networks in yeast cells and those in mammalian cardiac myocytes. This comparison covers not only the components, structure and function of the networks but also includes existing knowledge on the measured and simulated network dynamics using mathematical models. Surprisingly, most of the factors known in the yeast calcium homeostasis/signaling network are conserved and operate similarly in mammalian cells, including cardiac myocytes. Moreover, the budding yeast S. cerevisiae is a simple organism that affords powerful genetic and genomic tools. Thus, exploring and understanding the calcium homeostasis/signaling system in yeast can provide a shortcut to help understand calcium homeostasis/signaling systems in mammalian cardiac myocytes. In turn, this knowledge can be used to help treat relevant human diseases such as pathological cardiac hypertrophy and heart failure. [source]


Interpreting the Viking Age to Medieval period transition in Norse Orkney through cultural soil and sediment analyses

GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 4 2005
Ian A. Simpson
The transition from the Viking Age (ca. A.D. 800,1050) to the Medieval period (ca. A.D. 1050,1500) saw the development of widening trade activities that incorporated peripheral North Atlantic polities into mainstream Europe and contributed to the intensification of marineresource exploitation and agricultural production in these localities. As yet, there is only limited understanding of these intensification processes and their interrelationships, particularly at a local, site-based level. Through the micromorphological analysis of cultural soils and sediments at Quoygrew, Westray, Orkney, we explore the characteristics of farming and fishing activity during the Viking Age,Medieval transition period and establish their chronological relationships. The study demonstrates: (1) that intensification took place from ca. A.D. 966,1162 on an already existing Viking Age settlement, (2) that intensification of fishing activity occurred prior to the intensification of arable agriculture, and (3) that the Quoygrew site continued throughout this period as an economically diverse permanent settlement. When viewed in a wider North Atlantic context, these findings indicate that intensification of different economic activities proceeded at different rates and that intensification of specialized economic activities during the transition from the Viking Age to the Medieval period was dependent on existing knowledge of local environments. © 2005 Wiley Periodicals, Inc. [source]


Prevention and treatment of hepatitis C in injection drug users

HEPATOLOGY, Issue 5B 2002
Brian R. Edlin 3180 18th St.
Injection drug users constitute the largest group of persons infected with the hepatitis C virus (HCV) in the United States, and most new infections occur in drug users. Controlling hepatitis C in the U.S. population, therefore, will require developing, testing, and implementing effective prevention and treatment strategies for persons who inject drugs. Fortunately, a substantial body of research and clinical experience exists on the prevention and management of chronic viral diseases among injection drug users. The need to implement interventions to stop the spread of HCV among drug users is critical. The capacity of substance-use treatment programs need to be expanded to accommodate all who want and need treatment. Physicians and pharmacists should be educated in how to provide access to sterile syringes and to teach safe injection techniques, both of which are lifesaving interventions. The treatment of hepatitis C in drug users requires an interdisciplinary approach that brings together expertise in treating hepatitis and caring for drug users. Treatment decisions should be made individually by patients with their physicians, based on a balanced assessment of risks and benefits and the patient's personal values. Physicians should carefully assess, monitor, and support adherence and mental health in all patients, regardless of whether drug use is known or suspected. Research is needed to better understand how best to prevent and treat hepatitis C in substance users. In the meantime, substantial progress can be made if existing knowledge and resources are brought to bear. [source]


Development of a knowledge-based system for nonpowered hand tools (Tool Expert): Part I,The scientific basis

HUMAN FACTORS AND ERGONOMICS IN MANUFACTURING & SERVICE INDUSTRIES, Issue 3 2004
Berman Kayis
The need for developing a clear and concise guide for designing, selecting, and using hand tools would minimize if not eliminate acute,chronic trauma exposure factors and help improve efficiency, well-being, and morale. Despite several research efforts devoted to the exploration and understanding of the interrelation between human capabilities, task requirements, nature of tasks, and ergonomically designed hand tools, there appear to be several problems in utilizing existing knowledge in practical use. One of the most important barriers is the lack of interaction of several specialists from different backgrounds. In this article, TOOL-EXPERT, a knowledge-based system developed to assert the ergonomical nonpowered hand tool design, selection, and use, is explained, which will provide a guideline to several users from various backgrounds. The system is designed to run in any IBM-compatible personal computer system. Knowledge from several domains was included. The type of knowledge used in the research was selected to be a declarative knowledge. Altogether it includes 423 goals, 35 questions, and 40 rules. © 2004 Wiley Periodicals, Inc. Hum Factors Man 14: 257,268, 2004. [source]


Primary health care nursing staff in Crete: an emerging profile

INTERNATIONAL NURSING REVIEW, Issue 1 2006
A. Markaki rn
Background:, In 2001, the newly established Regional Health and Welfare System of Crete commissioned the first needs' assessment study of nursing personnel employed in the public sector of primary health care (PHC). Aim:, To capture the profile and professional needs of nursing staff working in Health Centers throughout the island of Crete and explore variations in nursing practice by educational preparation. Methods:, A newly developed, psychometrically tested questionnaire, was administered to all nursing staff in 14 rural Health Centers. Findings:, Vacancy rates are high, indicating a serious staffing deficit. The type of degree earned (2-year vs. 3 or 4-year program) does not differentiate nursing practice, with only two exceptions (obtaining a patient's history and counselling patients). The majority of respondents assess their existing knowledge and skills as ,adequate' while indicating a strong desire for continuing education. Job satisfaction is high in terms of interactions with clients and community recognition, while it is rated ,low' in terms of daily interactions with colleagues and support from work environment. Conclusion:, Cretan nursing staff in PHC operate within a restricted and task-orientated framework. Their educational preparation has little effect in practice role variations and professional needs. The Regional Health and Welfare System of Crete should address daily supervision and support issues, on-the-job training, continuing education needs, while taking immediate action to avoid potential turnover of existing staff and to aggressively recruit young, qualified nursing staff who will choose a career in PHC nursing. [source]


Modelling the efficacy of entomopathogenic nematodes in the regulation of invertebrate pests in glasshouse crops

JOURNAL OF APPLIED ECOLOGY, Issue 2 2000
A. Fenton
Summary 1. ,Entomopathogenic nematodes belonging to the families Heterorhabditidae and Steinernematidae are lethal obligate parasites of a wide range of invertebrate species. These nematodes exhibit many characteristics that make them ideal candidates as biological control agents of insect pests (rapid host death, high reproductive rates, easily mass-reared in vitro, easy application techniques). 2. ,However, at present, the number of pest species to which these nematodes are applied successfully is small. Clearly, there is a need to develop existing knowledge of the nematode into a more complete understanding of the nematode,pest system as a whole. 3. ,To consider the potential of entomopathogenic nematodes as biological control agents, we adopted a generalized analytical modelling approach and, using realistic parameter estimates, determined the conditions under which these nematodes can regulate a pest population. 4. ,Stability analyses suggested that entomopathogenic nematodes may not be capable of regulating a host population to a stable equilibrium. Long-term persistence of the host and nematode population is unlikely, due to the highly destabilizing effects of the parasite,host relationship. As such, these nematodes may be better suited to short-term control through inundative application techniques rather than long-term regulation. 5. ,This preliminary generalized model highlights areas where further work is needed. This includes estimation of the probability of nematode infection in the field, the effect of host size on the transmission cycle and the influence of spatial heterogeneity on stability. [source]


Biodiversity assessment: a case study in predicting richness from the potential distributions of plant species in the forests of south-western Australia

JOURNAL OF BIOGEOGRAPHY, Issue 5 2000
Paul Gioia
Abstract Distributions were predicted for 1430 native plant species as part of a biodiversity assessment in the forests of south-west Western Australia. From these predicted distributions, an index of plant species richness was generated for the forest area. The most common predictors for distribution were found to be climatic surfaces incorporating some aspect of seasonality in temperature and precipitation. Although coarse, the index confirmed existing knowledge of areas of high biodiversity within the study area and introduced a new area, the Blackwood Plateau, for consideration as a conservation reserve with high species richness. An additional survey was conducted to sample actual species richness in 11 test sites. When actual richness was regressed against predicted richness, a significant correlation was obtained if both annuals and geophytes were excluded from the analysis. With refinement of the model and further data collection targeted at areas of low effort, the species richness index is proposed as a useful tool for conservation planning. [source]


Literature review: considerations in undertaking focus group research with culturally and linguistically diverse groups

JOURNAL OF CLINICAL NURSING, Issue 6 2007
Elizabeth J Halcomb BN, IC Cert
Aims., This integrated literature review seeks to identify the key considerations in conducting focus groups and discusses the specific considerations for focus group research with culturally and linguistically diverse groups. Background., The focus group method is a technique of group interview that generates data through the opinions expressed by participants. Focus groups have become an increasingly popular method of data collection in health care research. Although focus groups have been used extensively with Western populations, they are a particularly useful tool for engaging culturally and linguistically diverse populations. The success of focus groups in this context is dependent upon the cultural competence of the research team and the research questions. Methods., The electronic databases Medline, CINAHL, Embase, Psychlit and the Internet using the Google Scholar search engine were explored using the search terms ,focus group', ,cultural sensitivity', ,transcultural nursing', ,transcultural care', ,cultural diversity' and ,ethnic groups'. Hand searching of reference lists and relevant journals was also undertaken. English language articles were selected for the review if they discussed the following issues: (i) methodological implications of the focus group method; (ii) strengths and limitations of the focus group method; (iii) recommendations for researchers and (iv) use of the focus group in culturally and linguistically diverse groups. Conclusions were drawn from each of the articles and consensus regarding a summary of recommendations was derived from a minimum of two authors. Results., Findings from this review revealed several key issues involving focus group implementation including recruitment, sample size, data collection, data analysis and use within multicultural populations. Strengths and limitations of the focus group method were also identified. Conclusions., Focus groups are a useful tool to expand existing knowledge about service provision and identify consumer needs that will assist in the development of future intervention programmes, particularly within multicultural populations. Careful planning related to methodological and pragmatic issues are critical in deriving effective data and protecting participants. Relevance to clinical practice., Focus groups can facilitate increased understanding of perspectives of culturally and linguistically diverse groups and thereby shape clinical practice to better meet the needs of these groups. [source]


Patterns of partners' abusive behaviors as reported by Latina and non-Latina survivors

JOURNAL OF COMMUNITY PSYCHOLOGY, Issue 2 2009
Nancy Glass
This study builds on the existing knowledge of risk factors for lethal intimate partner violence (IPV) and typologies of IPV abusers by exploring patterns of abusive partners' behaviors among known risk factors for intimate partner femicide (i.e., murder of women) and determines if groups of survivors with similar patterns of abusive behaviors exist. The common patterns are then examined for differences among Latina and non-Latina survivors. Face-to-face interviews were conducted with adult English- and Spanish-speaking survivors of past-year physical and/or sexual IPV using a validated risk assessment instrument, the Danger Assessment (DA) Questionnaire. Two-hundred nine IPV survivors participated, 55% Latina. Unique patterns of abusive behaviors perpetrated by an intimate partner or ex-partner across known risk factors for lethal violence were reported. The patterns clustered into five distinct groups: extreme abuser, physical and sexual violence/controlling abuser, forced sex/controlling abuser, threat/controlling abuser, and low-level tactics abuser. Latina and non-Latina survivors reported mean DA scores (13.0 vs. 18.5, respectively) that place them within the "increased danger" and "extreme danger" level, respectively, for lethal violence by an abusive partner. Although both groups were in extreme danger on average, the patterns of abusive behaviors differed. Latina women were more likely to characterize their partner as using forced sex to control the relationship, whereas non-Latina women were more likely to characterize the use of all types of abusive behaviors (i.e., extreme abuser) or threats to kill them (i.e., threat/controlling abuser) to control the relationship. The findings of this study can be used to develop effective individualized safety plans that include culturally and linguistically competent strategies to reduce violence-related morbidity and mortality. © 2009 Wiley Periodicals, Inc. [source]


Exploring the mathematics of motion through construction and collaboration

JOURNAL OF COMPUTER ASSISTED LEARNING, Issue 2 2006
G. Simpson
Abstract In this paper, we give a detailed account of the design principles and construction of activities designed for learning about the relationships between position, velocity and acceleration, and corresponding kinematics graphs. Our approach is model-based, that is, it focuses attention on the idea that students constructed their own models , in the form of programs , to formalise and thus extend their existing knowledge. In these activities, students controlled the movement of objects in a programming environment, recording the motion data and plotting corresponding position,time and velocity,time graphs. They shared their findings on a specially designed Web-based collaboration system, and posted cross-site challenges to which others could react. We present learning episodes that provide evidence of students making discoveries about the relationships between different representations of motion. We conjecture that these discoveries arose from their activity in building models of motion and their participation in classroom and online communities. [source]


Biology of the European large raspberry aphid (Amphorophora idaei): its role in virus transmission and resistance breakdown in red raspberry

AGRICULTURAL AND FOREST ENTOMOLOGY, Issue 1 2009
Lindsay S. McMenemy
Abstract 1,The European large raspberry aphid Amphorophora idaei Börner is the most important vector of viral diseases afflicting commercially grown red raspberry (Rubus idaeus L.) in Northern Europe, with European raspberry production amounting to 416 000 tonnes per annum. This review synthesizes existing knowledge on its biology and interactions with other organisms, including its host plant and the viral pathogens it vectors. 2,Information about trophic interactions with other insect herbivores and natural enemies is reviewed. Vine weevils Otiorhynchus sulcatus compromise aphid resistance in some raspberry cultivars, increasing A. idaei abundance by 80%. Parasitoids show mixed success in parasitizing A. idaei, although Aphidius ervi attack rates more than doubled when A. idaei fed on a partially susceptible raspberry cultivar, compared with a resistant variety. These findings are discussed in the context of potential biological control as part of an integrated pest and disease management framework. 3,Amphorophora idaei transmits four known viruses: Black raspberry necrosis virus, Raspberry leaf mottle virus, Raspberry leaf spot virus and Rubus yellow net virus, with A. idaei taking as little as 2 min to transmit some viruses. 4,Existing control strategies, including resistant cultivars, insecticides and eradication of disease from parent plants, are described. In particular, strong selection pressures have resulted in A. idaei overcoming genetic resistance in many raspberry cultivars and most insecticides are now ineffective. 5,Future directions for the sustained control of A. idaei are suggested, taking into consideration the possible effects of climate change and also changes in agronomic practices in U.K. agriculture. [source]


Approaches to overcoming constraints to effective health service delivery: a review of the evidence

JOURNAL OF INTERNATIONAL DEVELOPMENT, Issue 1 2003
Valeria Oliveira-Cruz
This paper reviews the current evidence base regarding efforts to overcome constraints to effective health service delivery in low and middle-income countries. A systematic literature review was chosen as the approach to gather and analyse existing knowledge about how to improve the ,close-to-client' health system. We focused on three levels of constraints: community and household, the health services delivery level itself, and health sector policy and strategic management. In total, 116 studies were reviewed and their main findings presented. The results should be interpreted with caution due to the considerable limitations in the existing evidence base. Copyright © 2003 John Wiley & Sons, Ltd. [source]


Contrasting Burns and Bass: Does the transactional-transformational paradigm live up to Burns' philosophy of transforming leadership?

JOURNAL OF LEADERSHIP STUDIES, Issue 3 2007
Dmitry Khanin
Both proponents and critics view the transactional-transformational paradigm (Bass, 1997, 1998) as the brainchild of Burns' (1978) philosophy of transforming leadership. However, Burns (2003) has criticized the paradigm's narrow managerialist orientation and the claim that it is uniformly applicable to any culture and organization. In this article, I first summarize and articulate Burns' (1978, 2003) and Bass' (1985, 1998) approaches toward leadership, then compare them by using a new four-dimensional framework. Extending previous research (Yukl, 2006), the framework represents a useful tool for detecting the commonalities and differences between leadership theories with respect to the core dimensions, categories, and aspects of leadership. My inspection indicates that Burns' and Bass' conceptions stem from disparate contexts and differ in their applicability. Thus, Burns' (1978) ideas stem from political movements ideally characterized by mutual quest for shared meaning and active collaboration between leaders and followers. Conversely, Bass' (1985) approach springs from military training in which leaders transfer existing knowledge to followers and stimulate their activity by using a variety of tools from inspirational motivation to individualized consideration. This study has important practical implications as it delineates the boundary conditions of the transactional-transformational paradigm and warns against its uncritical adoption in incongruent leadership contexts. [source]


International Sourcing: An Australian Perspective

JOURNAL OF SUPPLY CHAIN MANAGEMENT, Issue 1 2000
Nexhmi Rexha
SUMMARY International sourcing has emerged as an integral part of firms' competitive advantage building. In spite of increasing management attention to international sourcing, the literature is predominately based on U.S. research. Taking into account the impact of a firm's operational environment upon its sourcing strategies, the applicability of the existing knowledge outside the United States is highly questionable. This study provides new insights into the understanding of international sourcing from the unique perspective of Australia-located manufacturers. Intra-firm trade practice among Australian subsidiaries of multinationals is also investigated. While the study found distinctive international sourcing behaviors of Australia-located manufacturers, it also discovered a distinctive pattern of international sourcing practice. [source]


Residual analysis for spatial point processes (with discussion)

JOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES B (STATISTICAL METHODOLOGY), Issue 5 2005
A. Baddeley
Summary., We define residuals for point process models fitted to spatial point pattern data, and we propose diagnostic plots based on them. The residuals apply to any point process model that has a conditional intensity; the model may exhibit spatial heterogeneity, interpoint interaction and dependence on spatial covariates. Some existing ad hoc methods for model checking (quadrat counts, scan statistic, kernel smoothed intensity and Berman's diagnostic) are recovered as special cases. Diagnostic tools are developed systematically, by using an analogy between our spatial residuals and the usual residuals for (non-spatial) generalized linear models. The conditional intensity , plays the role of the mean response. This makes it possible to adapt existing knowledge about model validation for generalized linear models to the spatial point process context, giving recommendations for diagnostic plots. A plot of smoothed residuals against spatial location, or against a spatial covariate, is effective in diagnosing spatial trend or co-variate effects. Q,Q -plots of the residuals are effective in diagnosing interpoint interaction. [source]


Proteinaceous inhibitors of carbohydrate-active enzymes in cereals: implication in agriculture, cereal processing and nutrition,

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 11 2006
Nathalie Juge
Abstract Enzymes that degrade, modify, or create glycosidic bonds are involved in carbohydrate biosynthesis and remodelling. Microbial carbohydrate-active enzymes form the basis of current green technology in the food, feed, starch, paper and pulp industries and the revolution in genomics may offer long-term gains on the quality and quantity of the raw materials. Proteinaceous inhibitors of carbohydrate-active enzymes (,-amylase, limit-dextrinase, polygalacturonase, pectin lyase, pectin methylesterase, invertase and xyloglucan endoglucanase) naturally occur in plants where they are involved in various roles from plant defence to metabolism. Xylanase inhibitors represent the latest addition to this growing family. In this review, we will focus on the inhibitors of carbohydrate-active enzymes present in cereals, mostly represented by ,-amylase and xylanase inhibitors, and summarise the existing knowledge on their structure, function, and implication in cereal processing, agriculture and nutrition. Copyright © 2006 Society of Chemical Industry [source]


On the origin of bladder sensing: Tr(i)ps in urology,

NEUROUROLOGY AND URODYNAMICS, Issue 4 2008
Wouter Everaerts
Abstract The mammalian TRP family consists of 28 channels that can be subdivided into 6 different classes: TRPV (vanilloid), TRPC (canonical), TRPM (Melastatin), TRPP (Polycystin), TRPML (Mucolipin), and TRPA (Ankyrin). TRP channels are activated by a diversity of physical (voltage, heat, cold, mechanical stress) or chemical (pH, osmolality) stimuli and by binding of specific ligands, enabling them to act as multifunctional sensors at the cellular level. Currently, a lot of scientific research is devoted to these channels and their role in sensing mechanisms throughout the body. In urology, there's a growing conviction that disturbances in afferent (sensory) mechanisms are highly important in the pathogenesis of functional problems. Therefore, the TRP family forms an interesting new target to focus on. In this review we attempt to summarize the existing knowledge about TRP channels in the urogenital tract. So far, TRPV1, TRPV2, TRPV4, TRPM8, and TRPA1 have been described in different parts of the urogenital tract. Although only TRPV1 (the vanilloid receptor) has been extensively studied so far, more evidence is slowly accumulating about the role of other TRP channels in the (patho)physiology of the urogenital tract. Neurourol. Urodynam. 27:264,273, 2008. © 2007 Wiley-Liss, Inc. [source]


Catching a red herring: autumn colours and aphids

OIKOS, Issue 11 2009
T. C. R. White
The purpose of this note is not to support any particular hypothesis explaining the evolution of red coloured autumn leaves, but to present evidence that shows existing knowledge does not support one such hypothesis , that red coloured leaves evolved as a signal to protect trees from aphids feeding and laying eggs on them in autumn. An alternative hypothesis is that autumn-feeding aphids are senescence-feeders, evolved to feed only on senescing leaves. These aphids are programmed to detect and feed on such leaves when they are still green and yellow and actively exporting their nutrients. Aphids reject or ignore red leaves because they are no longer good food, not because they are protecting the trees from the aphids. [source]


Cystic fibrosis lung disease starts in the small airways: Can we treat it more effectively?

PEDIATRIC PULMONOLOGY, Issue 2 2010
Harm A.W.M. Tiddens MD
Abstract The aims of this article are to summarize existing knowledge regarding the pathophysiology of small airways disease in cystic fibrosis (CF), to speculate about additional mechanisms that might play a role, and to consider the available or potential options to treat it. In the first section, we review the evidence provided by pathologic, physiologic, and imaging studies suggesting that obstruction of small airways begins early in life and is progressive. In the second section we discuss how the relationships between CF transmembrane conductance regulator (CFTR), ion transport, the volume of the periciliary liquid layer and airway mucus might lead to defective mucociliary clearance in small airways. In addition, we discuss how chronic endobronchial bacterial infection and a chronic neutrophilic inflammatory response increase the viscosity of CF secretions and exacerbate the clearance problem. Next, we discuss how the mechanical properties of small airways could be altered early in the disease process and how remodeling can contribute to small airways disease. In the final section, we discuss how established therapies impact small airways disease and new directions that may lead to improvement in the treatment of small airways disease. We conclude that there are many reasons to believe that small airways play an important role in the pathophysiology of (early) CF lung disease. Therapy should be aimed to target the small airways more efficiently, especially with drugs that can correct the basic defect at an early stage of disease. Pediatr Pulmonol. 2010; 45:107,117. © 2010 Wiley-Liss, Inc. [source]


Attachment theory and emotions in close relationships: Exploring the attachment-related dynamics of emotional reactions to relational events

PERSONAL RELATIONSHIPS, Issue 2 2005
Mario Mikulincer
Attachment theory is a powerful framework for understanding affect regulation. In this article, we examine the role played by attachment orientation in shaping emotional reactions to interpersonal transactions within close relationships. Using our recent integrative model of attachment-system activation and dynamics as a guide (M. Mikulincer & P. R. Shaver, 2003), we review relevant evidence, present new findings, and propose hypotheses concerning how people with different attachment styles are likely to react emotionally to relational events. Specifically, we focus on attachment-related variations in the emotional states elicited by a relationship partner's positive and negative behaviors and by signals of a partner's (relationship relevant or relationship irrelevant) distress or pleasure. In so doing, we organize existing knowledge and point the way to future research on attachment-related emotions in close relationships. [source]


Strategies for controlling cassava mosaic virus disease in Africa

PLANT PATHOLOGY, Issue 5 2005
J. M. Thresh
Cassava mosaic disease (CMD) is caused by whiteflyborne viruses of the genus Begomovirus (family Geminiviridae). The disease has long been regarded as the most important of those affecting cassava in sub-Saharan Africa, and has been the subject of much research, especially since the onset of the current very damaging pandemic in eastern and central Africa. This review considers the main features of CMD and the various possible means of control. The main emphasis to date has been on the development and deployment of virus-resistant varieties. These are widely adopted in countries where CMD has caused serious problems, and provided a powerful incentive for farmers to abandon some of the most susceptible of their traditional varieties. Only limited use has been made of phytosanitation involving CMD-free planting material and the removal (roguing) of diseased plants. Cultural methods of control using varietal mixtures, intercrops or other cropping practices have also been neglected, and there is a need for much additional research before they can be deployed effectively. Nevertheless, the severe losses now being caused by CMD in many parts of sub-Saharan Africa could be greatly decreased through the application of existing knowledge. [source]


Understanding the ergonomic risk for musculoskeletal disorders in the United States agricultural sector

AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 7 2007
Kermit G. Davis PhD
Abstract Introduction Farming is a very large industry in the United States. Understanding the risks for injuries and more specifically musculoskeletal disorders in this industry poses a challenge for health officials. Methods A review was conducted of the existing peer-reviewed publications prior to December 2006 about injuries and musculoskeletal disorders for farmers and farm workers. The aim was to review existing knowledge concerning: (1) the prevalence, types, and causes of farm-related injuries, paying particular attention to musculoskeletal disorders and the special populations within the agricultural sector, and (2) interventions that have been developed to reduce risk factors associated with farm-related injuries. Results Farmers and farm workers experience high rates of low back, shoulder, and upper extremity disorders. Musculoskeletal disorders may disproportionately affect farm youth and migrant workers due to the types of farm tasks performed. There is an urgent need for improved and validated interventions to reduce exposures and to improve the health of farmers and farm workers. Discussion Future farm-related musculoskeletal disorder research should emphasize: (1) better identification of exposures for special populations, (2) development of interventions for diverse farm populations, and (3) identification of additional exposures for musculoskeletal disorders. Inadequate understanding of musculoskeletal disorders in farming impedes efforts to prevent this common and important type of occupational injuries on farms. Am. J. Ind. Med. 50:501,511, 2007. © 2007 Wiley-Liss, Inc. [source]


Anterior N2 predicts subsequent viewing time and interest rating for novel drawings

PSYCHOPHYSIOLOGY, Issue 5 2007
Hiroshi Nittono
Abstract Event-related brain potentials (ERPs) in response to novel pictures and subsequent visual exploration were examined. Eighteen undergraduates viewed 120 novel drawings as long as they wished. ERPs were calculated separately for drawings that were viewed longer or shorter than the median viewing time of each participant. The drawings viewed longer elicited a larger anterior negativity (N2) peaking at 245 ms than the shorter viewed drawings. This effect disappeared and the overall amplitude of the N2 decreased when the same set of drawings was presented again in a subsequent interest-rating session. Drawings rated as more interesting elicited a larger N2 than did drawings rated as less interesting. This study demonstrates a type of anterior N2 that is sensitive to stimulus unfamiliarity or difficulty in encoding, which reflects a conflict between stimulus input and existing knowledge and prompts further recognition processes and visual exploration. [source]


Managing innovation in a knowledge intensive technology organisation (KITO)

R & D MANAGEMENT, Issue 5 2002
Audrey Verhaeghe
This study aims to add to the existing knowledge of how innovation works in organisations. By understanding how to assess/evaluate processes that support and enable innovation, managers can better manage innovation as a business process. This paper addresses elements of organisational behaviour that relate to people management where innovation and technology management is concerned. Perception plays a crucial role in driving behaviour and therefore the widely accepted business scorecard methodology has been used to measure innovation practices in the organisation. The research was done in a knowledge intensive technology organisation (KITO) in South Africa. Interviews with managers of R&D were conducted. These interviews were used to adapt an existing audit instrument to suit the technology,based organisation. Thereafter, a comprehensive audit of innovation was conducted at three different management levels using the adapted instrument. Over 100, mostly R&D managers, were asked to complete a scorecard,based questionnaire and to draw a visual representation (VR) of innovation. The results of the interviews, audit and VRs were used to produce a management framework that is not only applicable to a KITO, but can also be used widely to improve innovation through enhanced visual understanding of any technology,based organisation. The results of the study indicate that measuring innovation through a validated instrument is highly valuable. The Holistic System Framework for innovation and the measurement instrument facilitated (1) management of, and (2) organisational learning about innovation. The comprehensive audit indicated, on a strategic level, the strengths and weaknesses of the innovation process as practised in the organisation. The instrument is valuable at a strategic management level as it indicates where in the organisation the gaps exist regarding the management of the process of innovation with the aim to create a competitive advantage. [source]


Practitioner Review: Outcomes for parents and children following non-traditional conception: what do clinicians need to know?

THE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 3 2003
Susan Golombok
Background: The birth of the first ,test-tube' baby in 1978 has led to the creation of family types that would not otherwise have existed. Methods: This paper examines research on the psychological outcomes for parents and children in assisted reproduction families with particular attention to the issues and concerns that have been raised by creating families in this way. Results: Parents of children conceived by assisted reproduction appear to have good relationships with their children, even in families where one parent lacks a genetic link with the child. With respect to the children themselves, there is no evidence of cognitive impairment in singleton children born at full term as a result of assisted reproduction procedures, although the findings regarding the cognitive development of intracytoplasmic sperm injection (ICSI) children are currently unclear. In relation to socioemotional development, assisted reproduction children appear to be functioning well. Conclusions: Few studies have included children at adolescence or beyond, and little is known about the consequences of conception by assisted reproduction from the perspective of the individuals concerned. In addition, there are some types of assisted reproduction family, such as families created through a surrogacy arrangement or through embryo donation, about whom little is known at all. Although existing knowledge about the impact of assisted reproduction for parenting and child development does not give undue cause for concern, there remain a number of unanswered questions in relation to children born in this way. [source]


Neurological disorders in complex humanitarian emergencies and natural disasters

ANNALS OF NEUROLOGY, Issue 3 2010
Farrah J. Mateen MD
Complex humanitarian emergencies include the relatively acute, severe, and overwhelming health consequences of armed conflict, food scarcity, mass displacement, and political strife. Neurological manifestations of complex humanitarian emergencies are important and underappreciated consequences of emergencies in populations worldwide. This review critically assesses the existing knowledge of the range of neurological disorders that accompany complex humanitarian emergencies and natural disasters in both the acute phase of crisis and the "long shadow" that follows. Ann Neurol 2010;68:282,294 [source]


Benchmarking habitat quality: observations using River Habitat Survey on near-natural streams and rivers in northern and western Europe

AQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue S1 2010
Paul J. Raven
Abstract 1.Some ecological effects of physically modifying rivers are still unclear, partly due to scale factors, but also because the character of high quality habitat is poorly understood. 2.Surveys at 278 sites on 141 near-natural streams and rivers in northern and western Europe were carried out between 1994 and 2009 to benchmark the habitat quality assessment system used for River Habitat Survey (RHS). 3.The objectives were to establish if RHS was suitable outside the UK, investigate if 500 m was still valid as the survey length, suggest a benchmarking strategy and recommend improvements to habitat quality assessment protocols. 4.Some modifications to RHS are needed to take account of differences in hydrological conditions, land-use and, most importantly, riparian habitat structure found in mainland Europe. 5.On average, 82,87% of channel attributes and 87,98% of channel and bank features were recorded within the first of consecutive RHS sites, confirming that 500 m is an effective sample length for characterizing small rivers. 6.Stream-flow character appeared to influence the distribution of several in-channel features, with greater diversity and between-site variation associated with rivers of mixed flow-types. To account for local variation and for effective use of survey time, it is recommended that two or more consecutive RHS sites are used for benchmarking purposes. 7.A suite of assessment protocols with agreed criteria and analytical rules, linked to specific objectives (e.g. nature conservation, geomorphic condition), is needed to establish the character and habitat quality of rivers in a consistent fashion. 8.A multi-discipline benchmarking programme using hydro-ecological regions in Europe would build on existing knowledge and help to improve both the inter-calibration and local application of quality assessment protocols. Data-sharing by hydrologists, river ecologists and fluvial geomorphologists would improve the basis for managing rivers in support of the European Water Framework Directive and Habitats Directive. Copyright © 2010 John Wiley & Sons, Ltd. [source]


Perturbation of retinoic acid (RA)-mediated limb development suggests a role for diminished RA signaling in the teratogenesis of ethanol,,§

BIRTH DEFECTS RESEARCH, Issue 9 2007
Corey S. Johnson
Abstract BACKGROUND: A proposed mechanism for ethanol teratogenicity entails ethanol-mediated reductions in retinoic acid (RA). This premise was investigated utilizing a mouse model, with limb reduction defects as the teratogenic end point. METHODS: Ethanol, Disulfiram, or BMS-189453 was administered to C57BL/6J mice on the 9th day of pregnancy. Forelimb morphology was assessed on gestation day 18 using Alcian blue and Alizarin red staining. Nile blue sulfate or LysoTracker Red (LTR) vital staining identified cell death in the limb bud. The ability of RA to prevent ethanol-induced cell death was assessed by coadministration followed by laser scanning confocal microscopic examination of LTR-staining. In situ hybridization and qPCR were used to examine gene expression in treated limb buds. RESULTS: Ethanol, Disulfiram, and BMS-189453 resulted in postaxial ectrodactyly, intermediate ectrodactyly, and other digital defects. Excessive Nile blue sulfate staining was evident in the presumptive AER following each of the three exposures. Ethanol-induced LTR staining was prevented by RA supplementation. Both in situ hybridization and qPCR illustrated decreases in Shh and Tbx5 in ethanol-exposed embryos as compared to control. CONCLUSIONS: Contrary to studies of prolonged RA deficiency, acute exposure to functional antagonists of RA results in limb defects that are morphologically similar to those caused by ethanol. The rescue of ethanol-induced cell death by RA and similar changes in Shh transcription further suggest that RA contributes to ethanol-induced limb dysmorphology. Moreover, the repression of key mediators of limb development soon after ethanol exposure adds to the existing knowledge of the pathogenic effects of ethanol. Birth Defects Research (Part A), 2007. © 2007 Wiley-Liss, Inc. [source]