Home About us Contact
|
Home About us Contact | ||
|
|
||
Special Challenges (special + challenge)
Selected AbstractsCommunicating with Subjects: Special Challenges for Resuscitation ResearchACADEMIC EMERGENCY MEDICINE, Issue 11 2005Ilene Wilets PhD Abstract In May 2005, Academic Emergency Medicine sponsored a one-day consensus conference held in association with the 2005 Society for Academic Emergency Medicine meeting in New York City. The conference, entitled "Ethical Conduct of Resuscitation Research," addressed a variety of issues regarding the successful conduct of research in acute care settings. A number of important breakout sessions were convened based on challenges specific to resuscitation research. "Communicating with Subjects" was one such session, dedicated toward perfecting the conduct of informed consent for research. The breakout session was attended by 15 insightful emergency medicine investigators, administrators, and ethicists. Issues of research information disclosure, subject comprehension, and the voluntariness of research participation were addressed. Consensus statements were developed and are discussed within this report. [source] The interim chair: Special challenges and opportunitiesNEW DIRECTIONS FOR HIGHER EDUCATION, Issue 126 2004Anthony G. Rud Jr. A substantial number of individuals serve as interim chairs each academic year. This chapter addresses their unique needs and provides suggestions on serving in this difficult role. [source] Analysis of integral membrane proteins by heat gel-embedment combined with improved in-gel digestionsELECTROPHORESIS, Issue 23 2009Jian Zhou Abstract Analysis of integral membrane proteins (IMPs) presents a special challenge because of their hydrophobic nature and low abundance. Here, a new method was developed, which involved heat gel-embedment and improved in-gel digestion of the proteins. Membrane protein lysate containing detergents was mixed with acrylamide solution and the proteins were embedded when the gel polymerized. For comparison, the protein embedment was made at different temperatures (25, 35 or 45°C), and the in-gel digestions were performed in the presence of 0.1% RapiGest reagent (ALS), 0.1% sodium deoxycholate and 10% ACN, respectively. The resultant peptides were extracted and analyzed by capillary liquid chromatography coupled with tandem mass spectrometry. Compared with that at 25°C, gel-embedment at 45°C improved the protein embedment and thus protein identification, with the identified IMPs increased by 27%. 0.1% sodium deoxycholate was more efficient than 0.1% ALS and 10% ACN in terms of improving the digestion and tryptic digest recovery of the gel-embedded proteins particularly the hydrophobic IMPs. Out of the 326 IMPs identified by heat gel-embedment combined with improved in-gel digestion strategies, 149 (46%) proteins had at least two mapped transmembrane domains. These results indicate that our newly developed protocol could facilitate the high throughput analysis of integral membrane proteome. [source] Vitamin D and calcium deficits predispose for multiple chronic diseasesEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 5 2005M. Peterlik Abstract There is evidence from both observational studies and clinical trials that calcium malnutrition and hypovitaminosis D are predisposing conditions for various common chronic diseases. In addition to skeletal disorders, calcium and vitamin D deficits increase the risk of malignancies, particularly of colon, breast and prostate gland, of chronic inflammatory and autoimmune diseases (e.g. insulin-dependent diabetes mellitus, inflammatory bowel disease, multiple sclerosis), as well as of metabolic disorders (metabolic syndrome, hypertension). The aim of the present review was to provide improved understanding of the molecular and cellular processes by which deficits in calcium and vitamin D cause specific changes in cell and organ functions and thereby increase the risk for chronic diseases of different aetiology. 1,25-dihydroxyvitamin D3 and extracellular Ca++ are both key regulators of proliferation, differentiation and function at the cellular level. However, the efficiency of vitamin D receptor-mediated intracellular signalling is limited by the negative effects of hypovitaminosis D on extrarenal 25-hydroxyvitamin D-1,-hydroxylase activity and thus on the production of 1,25-dihydroxyvitamin D3. Calcium malnutrition eventually causes a decrease in calcium concentration in extracellular fluid compartments, resulting in organ-specific modulation of calcium-sensing receptor activity. Hence, attenuation of signal transduction from the ligand-activated vitamin D receptor and calcium-sensing receptor seems to be the prime mechanism by which calcium and vitamin D insufficiencies cause perturbation of cellular functions in bone, kidney, intestine, mammary and prostate glands, endocrine pancreas, vascular endothelium, and, importantly, in the immune system. The wide range of diseases associated with deficits in calcium and vitamin D in combination with the high prevalence of these conditions represents a special challenge for preventive medicine. [source] On the compensation of non-active current components of three-phase loads with quickly changing unsymmetryEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 5 2001V. Staudt Some types of loads, like arc furnaces, present a special challenge to compensation strategies. They vary quickly and have a very high rated power. For example the arcs of an arc furnace are not burning continuously especially when starting the melting process. This causes variations of the line voltage with frequencies well below the line frequency commonly known as voltage flicker. Because of cost efficiency the energy storage capability of compensators for the mitigation of voltage flicker effects can still only be small compared to the energy taken by the arc furnace during one period of the line voltage. This paper discusses the use of a compensation tool which quickly detects negative sequence current components in comparison to the calculation of an equivalent conductance using the so-called FBD method (Fryze-Buchholz-Depenbrock method). Simulations are used to demonstrate the advantages and disadvantages of the tool for detecting negative sequence current components. It is shown that the quick detection and compensation of negative sequence current components can reduce the amount of voltage flicker considerably. [source] A rating scale for wildness and ease of handling laboratory mice: results for 21 inbred strains tested in two laboratoriesGENES, BRAIN AND BEHAVIOR, Issue 2 2003D. Wahlsten Rating scales for difficulty in capturing and holding mice were devised that proved to be easy to use and highly sensitive to differences among mouse strains on the A and B priority lists of the Mouse Phenome Project. The simplicity of the scales makes it feasible to rate wildness during behavioral test sessions without adding much to testing time or distracting the technician from the principal task at hand. Overall wildness and placidity ratings obtained by combining capture and hold ratings provide a good impression of the difficulties encountered while working with lab mice in the course of complex experiments. Ratings of 21 inbred strains during the course of 15 behavioral tests in two laboratories demonstrated that the SPRET/Ei, PERA/Ei, CAST/Ei and SWR/J strains were particularly difficult to handle. The NOD/LtJ strain posed no special challenge in the Edmonton laboratory but was very difficult to handle in the Portland lab. The rating scales should be useful for judging the difficulties in working with novel targeted or induced mutations in mice as well as effects of a variety of environmental treatments or drugs. [source] Treading on Tradition: Approaches to Teaching International Relations to the Nontraditional UndergraduateINTERNATIONAL STUDIES PERSPECTIVES, Issue 1 2002Nancy E. Wright Nontraditional undergraduates (NTUs), undergraduates who typically are older than average, work full-time, and/or are entrusted with substantial family responsibilities, pose a special challenge to international relations educators. Severe constraints on time and access to library facilities both impede progress and may give an erroneous impression that NTUs are not as committed to their education as more conventional college undergraduates. The lack of continuity in education that typifies the NTU experience often manifests itself in anxiety, frustration, and gaps in fundamental knowledge. At the same time, the maturity and sophistication that come with life experience often far exceed that of the more conventional college student. Furthermore, typical requirements of international relations and international studies majors, such as second and third language proficiency, internships with international organizations, and overseas study are often not feasible for the working student with family responsibilities. Possibilities for meeting the challenges of teaching NTUs include greater use of open-book examinations, research proposals, case studies, simulations, problem-based learning (PBL), use of the Internet, and the development of short-term intensive overseas study opportunities that accommodate the working student's schedule. [source] Perspectives on the Past: A Study of the Spatial Perspectival Characteristics of Recollective MemoriesMIND & LANGUAGE, Issue 2 2007DOROTHEA DEBUS I begin by considering the ,Past-Dependency-Claim', which states that every recollective memory (or ,R-memory') has its spatial perspectival characteristics in virtue of the subject's present awareness of the spatial perspectival characteristics of a relevant past perceptual experience. Although the Past-Dependency-Claim might for various reasons seem particularly attractive, I show that it is false. I then proceed to develop and defend the ,Present-Dependency-Claim', namely the claim that the spatial perspectival characteristics of an R-memory depend on the spatial perspectival characteristics of perceptual experiences that the subject has at the time at which the R-memory occurs. Lastly, I discuss the phenomenon of so-called ,observer-memories', which presents a special challenge for any attempt to account for the spatial perspectival characteristics of R-memories. I argue that we have no good reason to deny that the relevant experiences should count as memories, and I show that we can account for the spatial perspectival characteristics of observer-memories with the help of the ,Present-Dependency-Claim'. More generally, the paper shows that certain events that occur in a subject's mental life (namely, a subject's R-memories) are necessarily dependent on other events that occur in the relevant subject's mental life (namely, on certain perceptual experiences). This more general conclusion in turn should be relevant for any attempt to develop an appropriate account of a subject's mental life as a whole. [source] Australian Federalism Confronts Globalisation: A New Challenge at the CentenaryAUSTRALIAN JOURNAL OF PUBLIC ADMINISTRATION, Issue 3 2002John M Kline Globalisation poses a special challenge for federal systems of government. Despite administrative reforms, Australia has not fully confronted crucial questions regarding the role of states and territories when international issues overlap areas of subnational government authority. This challenge emerged with controversies over environmental regulations, import quarantines and Aboriginal policies. Initial reforms focused mainly on treaty approval processes, leaving broader policy questions largely unexamined. Subnational governments sometimes react protectively when facing dislocation threats from global forces; conversely, they can carry out constituency representation and education functions in ways that promote Australia's competitiveness and counter public distrust of globalisation. Federalism's new challenge is to devise political processes that foster positive state and territorial participation in Australia's response to globalisation. [source] Monopilegründungen von Offshore-Windenergieanlagen , Zum Ansatz der BettungBAUTECHNIK, Issue 1 2005Jürgen Grabe Univ.-Prof. Bei der Gründung von Offshore-Windenergieanlagen mit Monopiles stellt die große Momenten- und Horizontalkraftbelastung und deren zyklisches Auftreten eine besondere Herausforderung an die Prognose der Pfahlverformungen dar. Für ein System mit beispielhaften Abmessungen, Baugrundverhältnissen und Belastungen werden die konventionellen Verfahren zur Berechnung der horizontalen Pfahltragfähigkeit und -verformung, Bettungsmodulverfahren und API-Verfahren, mit den Ergebnissen einer 3D-FE-Analyse verglichen. Es zeigt sich, daß die konventionellen Verfahren für die Prognose der Verformungen im Gebrauchszustand, also deutlich unterhalb der Grenzlast, für dieses Beispiel unzureichend sind. Die Verteilung des Bettungsmoduls über die Tiefe wird mit keinem der Verfahren zutreffend abgebildet. Des weiteren wird die Veränderung des Bettungsmoduls über mehrere Zyklen für Schwell- und Wechselbelastungen untersucht. Vor allem bei einer Schwellast wird der auf den Ausgangszustand bezogene Bettungsmodul mit jedem Zyklus verändert. Die Verschiebung des Pfahlkopfs steigt auch nach 20 Belastungszyklen noch an. Der aus der ödometrischen Steifigkeit des Bodens abgeleitete Bettungsmodul ist zur Prognose der Pfahlverformungen insbesondere bei zyklischer Last fragwürdig. Hierfür besteht insbesondere in Anbetracht der geplanten Investitionen erheblicher Forschungsbedarf. Monopile foundations for Offshore-Wind Power Plants , approach of subgrade reaction. The large moments and horizontal forces and their cyclic occurrence represent a special challenge to the prognosis of the deformations of Monopiles as a foundation of offshore wind energy plants. The conventional procedures for the computation of the horizontal pile bearing capacity and deformation, subgrade reaction procedure and API procedure, are compared with the results of a 3D-FE analysis for a system with exemplary dimensions, soil conditions and loads. It is shown that the conventional procedures for the prognosis of the deformations in the serviceability limit state, thus clearly underneath the maximum load, for this example are insufficient. The distribution of the subgrade reaction modulus over the depth is sufficiently approximated with none of these procedures. Moreover the change of the subgrade reaction modulus is investigated for several cycles swelling and alternated loads. The modulus of subgrade reaction, referred to the initial pile position, changes especially under swelling loads for each loading cycle. The displacement of the pilehead still increases after 20 cycles. The modulus of subgrade reaction derived from the oedometric soil stiffness does not produce an accurate prognosis of the pile deformation particularly for cyclic loads. For this purpose further investigations are necessary. [source] Creating your policy governance tool kitBOARD LEADERSHIP: POLICY GOVERNANCE IN ACTION, Issue 50 2000Caroline Oliver The Board that is working hard to use Policy Governance faces a special challenge when searching for tools to help it do its work. It needs to make sure that the tools it chooses and the tools it develops on its own are truly a help and not a hindrance in getting the full benefits of Policy Governance. Caroline Oliver, a governance consultant based in Canada and editor of The Policy Governance Fieldbook Practical Lessons, Tips, and Tools from the Experiences of Real-World Boards (San Francisco: Jossey-Bass, 1999), sheds some light on what kind of tools are helpful and how to choose wisely. [source] Development, Productivity, and Sustaining Natural CapitalCANADIAN JOURNAL OF AGRICULTURAL ECONOMICS, Issue 1 2008Terrence S. Veeman The elimination of hunger, the reduction of poverty, and the wiser management of natural capital remain as critical, but elusive, objectives of society worldwide. In this Address, the issues of development, productivity, and the use of natural capital are explored and important linkages among these three areas are drawn. A special challenge is the identification of the conditions under which the productive base of a nation or region would increase on a sustainable basis, enhancing well-being of its citizens over time. Policy reforms are identified, which would help to ensure that development is more sustainable, that productivity growth is adequate and appropriate, and that natural capital, particularly its critical components, is managed more wisely. L'élimination de la faim, la réduction de la pauvreté et la gestion judicieuse du capital naturel demeurent, pour les sociétés de partout dans le monde, des objectifs extrêmement importants, mais difficiles à atteindre. Le présent exposé analyse les questions liées au développement, à la productivité et à l'utilisation du capital naturel, et établit d'importants liens entre ces trois domaines. La détermination des conditions qui contribueraient à augmenter de façon viable la base productive d'une nation ou d'une région, et ainsi accroître le bien-être de tous ses citoyens au fil du temps, pose un défi de taille. Les réformes politiques qui aideraient à assurer un développement durable, une croissance de la productivité adéquate et appropriée ainsi qu'une gestion judicieuse du capital naturel, particulièrement des éléments essentiels, sont mises en lumière. [source] Conservation biogeography , foundations, concepts and challengesDIVERSITY AND DISTRIBUTIONS, Issue 3 2010David M. Richardson Abstract Conservation biogeography involves the application of biogeographical principles, theories, and analyses to problems regarding biodiversity conservation. The field was formally defined in 2005, and considerable research has been conducted in the ensuing 5 years. This editorial sets the context for 16 contributions in a special issue of Diversity and Distributions on developments and challenges in conservation biogeography. Papers are grouped into the following main themes: species distribution modelling; data requirements; approaches for assigning conservation priorities; approaches for integrating information from numerous disparate sources; special challenges involving invasive species; and the crucial issue of determining how elements of biodiversity are likely to respond to rapid climate change. One paper provides a synthesis of requirements for a robust conservation biogeography for freshwater ecosystems. Conservation biogeography is well poised to make a significant contribution to the process of providing policy makers with objectively formulated scenarios and options for the effective management of biodiversity. The editorial, and the papers in the special issue, deliberate on many of the exciting developments in play in the field, and the many complex challenges that lie ahead. [source] Comparative Analysis of Adult versus Adolescent Sexual Assault: Epidemiology and Patterns of Anogenital InjuryACADEMIC EMERGENCY MEDICINE, Issue 8 2003Jeffrey S. Jones MD Abstract Objectives: To compare the characteristics of sexual assault in pubertal girls (<18 years old) and adults in a community-based population of women presenting to an urban sexual assault clinic. Methods: This case-series analysis evaluated consecutive female patients presenting to a sexual assault clinic during a three-year study period. The clinic is associated with a university-affiliated emergency medicine residency program and is staffed by forensic nurses trained to perform medicolegal examinations using colposcopy with nuclear staining. Patient demographics, assault characteristics, and injury patterns were recorded using a standardized classification system. Data from the two patient groups (adolescents vs. women ,18 years of age) were analyzed using chi-square test and t-test. Results: A total of 766 cases were identified: 43% of the victims were 13 to 17 years old (mean 15.0 years old), and 57% were older than 17 years old (mean 30.8 years old). Adolescents were more likely to be assaulted by an acquaintance or relative (84% vs. 50%, p < 0.001) and to delay medical evaluation (17 hours vs. 12 hours, p < 0.001) than were older women. Adolescent sexual assault was less likely to involve weapons or physical coercion (29% versus 57%, p < 0.001) and was associated with fewer nongenital injuries (33% vs. 55%, p < 0.001). Adolescents had a greater frequency of anogenital injuries (83% vs. 64%, p < 0.001), however, compared with older women. Common sites of injury in adolescents were posterior, including the fossa navicularis, hymen, fourchette, and labia minora. The injuries showed consistent topologic features, varying with the site and nature of tissue. Adult victims of sexual assault had a less consistent pattern of anogenital injuries with fewer hymenal injuries, greater injury to the perianal area, and widespread erythema. Conclusions: Of women presenting to an urban sexual assault clinic, 43% were adolescents. The epidemiology of sexual trauma and the pattern of anogenital trauma in this age group are unique and may pose special challenges to emergency health care providers. [source] Mass-independent fractionation of sulfur isotopes in sulfides from the pre-3770 Ma Isua Supracrustal Belt, West GreenlandGEOBIOLOGY, Issue 4 2006D. PAPINEAU ABSTRACT Redox chemistry of the coupled atmosphere,hydrosphere system has coevolved with the biosphere, from global anoxia in the Archean to an oxygenated Proterozoic surface environment. However, to trace these changes to the very beginning of the rock record presents special challenges. All known Eoarchean (c. 3850,3600 Ma) volcanosedimentary successions (i.e. supracrustal rocks) are restricted to high-grade gneissic terranes that seldom preserve original sedimentary structures and lack primary organic biomarkers. Although complicated by metamorphic overprinting, sulfur isotopes from Archean supracrustal rocks have the potential to preserve signatures of both atmospheric chemistry and metabolic fractionation from the original sediments. We present a synthesis of multiple sulfur isotope measurements (32S, 33S and 34S) performed on sulfides from amphibolite facies banded iron-formations (BIFs) and ferruginous garnet-biotite (metapelitic) schists from the pre-3770 Ma Isua Supracrustal Belt (ISB) in West Greenland. Because these data come from some of the oldest rocks of interpretable marine sedimentary origin, they provide the opportunity to (i) explore for possible biosignatures of sulfur metabolisms in early life; (ii) assess changes in atmospheric redox chemistry from ,3.8 Ga; and (iii) lay the groundwork to elucidate sulfur biogeochemical cycles on the early Earth. We find that sulfur isotope results from Isua do not unambiguously indicate microbially induced sulfur isotopic fractionation at that time. A significantly expanded data set of ,33S analyses for Isua dictates that the atmosphere was devoid of free oxygen at time of deposition and also shows that the effects of post-depositional metamorphic remobilization and/or dilution can be traced in mass-independently fractionated sulfur isotopes. [source] Home management of haemophiliaHAEMOPHILIA, Issue 2 2004J. M. Teitel Summary., The demonstrated benefits of home care for haemophilia include improved quality of life, less pain and disability, fewer hospitalizations, and less time lost from work or school. Although reduced mortality has not been demonstrated, the substantial increase in longevity since the early 1980s correlates with the introduction of home treatment and prophylaxis programmes. These programmes must be designed and monitored by haemophilia treatment centres (HTC), which are staffed with professionals with broad and complementary expertise in the disease and its complications. In return, patients and their families must be willing to accept the reciprocal responsibilities that come from administering blood products or their recombinant equivalents at home. Patients with inhibitors to factors VIII or IX pose special challenges, but these complications do not obviate participation in home care programmes. Home care was an essential prerequisite to the introduction of effective prophylactic factor replacement therapy. Prophylaxis offers significant improvements in quality of life, but requires a substantial commitment. The use of implantable venous access devices can eliminate some of the difficulty and discomfort of peripheral venous access in small children, but brings additional risks. The future holds the promise of factor concentrates for home use that have longer half-lives, or can be administered by alternate routes. Knowledge of patient genotypes may allow treatments tailored to avoid complications such as inhibitor development. Gene therapy trials, which are currently ongoing, will ultimately lead to gene-based treatments as a complement to traditional protein-based therapy. [source] The structure of dentine in the apical region of human teethINTERNATIONAL ENDODONTIC JOURNAL, Issue 5 2001I. A. Mjör Abstract Aim To study the structure of the apical region of human teeth with emphasis on dentinal tubules and their branches. Methodology This descriptive histological study employed demineralized stained sections for light microscopy, demineralized unstained sections for scanning electron microscopy, and undemineralized, acid-etched specimens for confocal tandem scanning microscopy. Results The apical portion of human teeth showed marked variations in structure, including accessory root canals, areas of resorption and repaired resorptions, occasional attached, embedded and free pulp stones, varied amounts of irregular secondary dentine, and even cementum-like tissue lining the apical root canal wall. The apex often deviated from the long axis of the root canal. Primary dentinal tubules were irregular in direction and density. Some areas were devoid of tubules. Conclusions The irregular and variable structure of the apical region of human teeth represent special challenges during endodontic therapy. Obturation techniques based on the penetration of adhesives into dentinal tubules are unlikely to be successful and adhesive techniques must depend on impregnation of a hybrid layer. [source] The Russian Federation: Confronting the special challenges of ageing and social security policy in an era of demographic crisisINTERNATIONAL SOCIAL SECURITY REVIEW, Issue 3-4 2010Nicholas Eberstadt Abstract This article focuses on the Russian Federation's demographic crisis and the implications it holds for the ability of the Russian government (or the Russian people through their own efforts) to generate enough funds to provide a reasonable level of old-age economic security. Although Russia's overall population profile structure stands to be broadly similar to that of other more-developed societies, both today and in coming decades, the challenges of providing for an ageing population are far more acute for Russia than for typical Member States of the Organisation for Economic Co-operation and Development. One factor that adds significantly to the problem is that working-age Russians today suffer substantially worse health and higher mortality than residents of other countries at similar , and indeed even at much lower , levels of income. Although the arguments presented focus on pensions, the same factors that will make it difficult to supply adequate pensions also mean that other aspects of social protection will be similarly difficult to fulfil. Successful social security policy for Russia, consequently, will depend upon much more than social programmes alone: it will require the reduction of mortality rates for working-age individuals, the revitalization of higher education, and fundamental reform of the country's institutions and economic policies. [source] The revenge of the Patterson methods.JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 5 2007In the present paper, the third and last of a series (the first two papers were dedicated to the crystal structure solution of proteins), the Patterson superposition method, based on the use of the symmetry minimum function, has been applied to powder diffraction patterns. The method has been modified to take into account the special challenges of this kind of data and to optimize the performance of the approach. The new algorithms have been implemented in a computer program and applied also to single-crystal data of small and medium-size crystal structures. The experimental results have been compared with those obtained via direct methods, so enabling the role and the perspectives of these two approaches in the global phasing problem to be established, no matter what the experimental technique (powder or single-crystal diffraction) or the size of the structures (small, medium or macro-molecules). [source] Grasping at the routes of biological invasions: a framework for integrating pathways into policyJOURNAL OF APPLIED ECOLOGY, Issue 2 2008P. E. Hulme Summary 1Pathways describe the processes that result in the introduction of alien species from one location to another. A framework is proposed to facilitate the comparative analysis of invasion pathways by a wide range of taxa in both terrestrial and aquatic ecosystems. Comparisons with a range of data helped identify existing gaps in current knowledge of pathways and highlight the limitations of existing legislation to manage introductions of alien species. The scheme aims for universality but uses the European Union as a case study for the regulatory perspectives. 2Alien species may arrive and enter a new region through three broad mechanisms: importation of a commodity, arrival of a transport vector, and/or natural spread from a neighbouring region where the species is itself alien. These three mechanisms result in six principal pathways: release, escape, contaminant, stowaway, corridor and unaided. 3Alien species transported as commodities may be introduced as a deliberate release or as an escape from captivity. Many species are not intentionally transported but arrive as a contaminant of a commodity, for example pathogens and pests. Stowaways are directly associated with human transport but arrive independently of a specific commodity, for example organisms transported in ballast water, cargo and airfreight. The corridor pathway highlights the role transport infrastructures play in the introduction of alien species. The unaided pathway describes situations where natural spread results in alien species arriving into a new region from a donor region where it is also alien. 4Vertebrate pathways tend to be characterized as deliberate releases, invertebrates as contaminants and plants as escapes. Pathogenic micro-organisms and fungi are generally introduced as contaminants of their hosts. The corridor and unaided pathways are often ignored in pathway assessments but warrant further detailed consideration. 5Synthesis and applications. Intentional releases and escapes should be straightforward to monitor and regulate but, in practice, developing legislation has proved difficult. New introductions continue to occur through contaminant, stowaway, corridor and unaided pathways. These pathways represent special challenges for management and legislation. The present framework should enable these trends to be monitored more clearly and hopefully lead to the development of appropriate regulations or codes of practice to stem the number of future introductions. [source] Finding the Findings in Qualitative StudiesJOURNAL OF NURSING SCHOLARSHIP, Issue 3 2002Margarete Sandelowski Purpose: To describe the challenges of finding the findings in qualitative studies. Method: Review of literature on representation in qualitative research and analysis of 99 reports of qualitative studies of women with HIV infection. Findings: Factors complicating finding the findings in qualitative studies include varied reporting styles, misrepresentation of data and analytic procedures as findings, misuse of quotes and theory, and lack of clarity concerning pattern and theme. Theses and dissertations present special challenges because they often contain several of these problems. Conclusions: Given the varied beliefs about findings among qualitative researchers, the challenge is to find ways to present findings that will make them discernible to the diverse audiences for whom they are intended, including researchers and practitioners. [source] Computational methods in authorship attributionJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 1 2009Moshe Koppel Statistical authorship attribution has a long history, culminating in the use of modern machine learning classification methods. Nevertheless, most of this work suffers from the limitation of assuming a small closed set of candidate authors and essentially unlimited training text for each. Real-life authorship attribution problems, however, typically fall short of this ideal. Thus, following detailed discussion of previous work, three scenarios are considered here for which solutions to the basic attribution problem are inadequate. In the first variant, the profiling problem, there is no candidate set at all; in this case, the challenge is to provide as much demographic or psychological information as possible about the author. In the second variant, the needle-in-a-haystack problem, there are many thousands of candidates for each of whom we might have a very limited writing sample. In the third variant, the verification problem, there is no closed candidate set but there is one suspect; in this case, the challenge is to determine if the suspect is or is not the author. For each variant, it is shown how machine learning methods can be adapted to handle the special challenges of that variant. [source] Microarray expression profiling: capturing a genome-wide portrait of the transcriptomeMOLECULAR MICROBIOLOGY, Issue 4 2003Tyrrell Conway Summary The bacterial transcriptome is a dynamic entity that reflects the organism's immediate, ongoing and genome-wide response to its environment. Microarray expression profiling provides a comprehensive portrait of the transcriptional world enabling us to view the organism as a ,system' that is more than the sum of its parts. The vigilance of microorganisms to environmental change, the alacrity of the transcriptional response, the short half-life of bacterial mRNA and the genome-scale nature of the investigation collectively explain the power of this method. These same features pose the most significant experimental design and execution issues which, unless surmounted, predictably generate a distorted image of the transcriptome. Conversely, the expression profile of a properly conceived and conducted microarray experiment can be used for hypothesis testing: disclosure of the metabolic and biosynthetic pathways that underlie adaptation of the organism to chang-ing conditions of growth; the identification of co-ordinately regulated genes; the regulatory circuits and signal transduction systems that mediate the adaptive response; and temporal features of developmental programmes. The study of bacterial pathogenesis by microarray expression profiling poses special challenges and opportunities. Although the technical hurdles are many, obtaining expression profiles of an organism growing in tissue will probably reveal strategies for growth and survival in the host's microenvironment. Identifying these colonization strategies and their cognate expression patterns involves a ,deconstruction' process that combines bioinformatics analysis and in vitro DNA array experimentation. [source] Identity issues in building an ESL community: The Puerto Rican experienceNEW DIRECTIONS FOR ADULT & CONTINUING EDUCATION, Issue 121 2009Betsy Morales English has a unique status in Puerto Rico, giving rise to special challenges in building community and teaching English as a second language on the island. Identity is at the core of these issues. [source] How international students can benefit from a web-based college orientationNEW DIRECTIONS FOR HIGHER EDUCATION, Issue 117 2002Christina Murphy As colleges and universities increasingly seek to recruit more international students, they must also look for ways of preparing those students to meet the special challenges of undertaking a new academic experience in a foreign environment. One way to prepare students is by using Web-based orientation. [source] Factors influencing the performance of English as an Additional Language nursing students: instructors' perspectivesNURSING INQUIRY, Issue 3 2009Tam Truong Donnelly The increasing number of immigrants in Canada has led to more nursing students for whom English is an additional language (EAL). Limited language skills, cultural differences, and a lack of support can pose special challenges for these students and the instructors who teach them. Using a qualitative research methodology, in-depth interviews with fourteen EAL nursing students and two focus group interviews with nine instructors were conducted. In this paper, the instructors' perspectives are presented. Data acquired from the instructors suggest that the challenges experienced by EAL students and instructors reside in a lack of awareness and support at the institutional and structural levels rather than solely on capacities of individual EAL students or instructors. From this study, identification of supportive activities for nurse educators and education sector decision makers emerged. [source] Regulatory Frameworks for Functional Foods and Dietary SupplementsNUTRITION REVIEWS, Issue 2 2004Christine Lewis Taylor Ph.D. An understanding of the legal and regulatory requirements for foods, including dietary supplements and so-called functional foods, helps to focus attention on the special challenges that exist, which range from safety determinations to claim substantiation and consumer understanding. This article provides an overview of the Food and Drug Administration's regulatory framework for these products; it also highlights issues that are emerging and will require consideration and dialog [source] Confined dynamics of a ribosome-bound nascent globin: Cone angle analysis of fluorescence depolarization decays in the presence of two local motionsPROTEIN SCIENCE, Issue 10 2009Jamie P. Ellis Abstract We still know very little about how proteins achieve their native three-dimensional structure in vitro and in the cell. Folding studies as proteins emerge from the mega Dalton-sized ribosome pose special challenges due to the large size and complicated nature of the ribosome-nascent chain complex. This work introduces a combination of three-component analysis of fluorescence depolarization decays (including the presence of two local motions) and in-cone analysis of diffusive local dynamics to investigate the spatial constraints experienced by a protein emerging from the ribosomal tunnel. We focus on E. coli ribosomes and an all-,-helical nascent globin in the presence and absence of the cotranslationally active chaperones DnaK and trigger factor. The data provide insights on the dynamic nature and structural plasticity of ribosome-nascent chain complexes. We find that the sub-ns motions of the N-terminal fluorophore, reporting on the globin dynamics in the vicinity of the N terminus, are highly constrained both inside and outside the ribosomal tunnel, resulting in high-order parameters (>0.85) and small cone semiangles (<30°). The shorter globin chains buried inside the tunnel are less spatially constrained than those of a reference sequence from a natively unfolded protein, suggesting either that the two nascent chain sequences have a different secondary structure and therefore sample different regions of the tunnel or that the tunnel undergoes local structural adjustments to accommodate the globin sequence. Longer globins emerging out of the ribosomal tunnel are also found to have highly spatially constrained slow (ns) motions. There are no observable spectroscopic changes in the absence of bound chaperones. [source] Lesson plan for protein exploration in a large biochemistry class,BIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION, Issue 5 2003David W. Honey Abstract The teaching of structural concepts plays a prominent role in many chemistry and biology courses. When it comes to macromolecular systems, a thorough understanding of noncovalent interactions lays a strong foundation for students to understand such things as protein folding, the formation of protein-ligand complexes, and the melting of the DNA double helix. The incorporation of computer-based molecular graphics into the biochemistry curriculum has given students unique opportunities in visualizing the structure of biological molecules and recognizing the subtle aspects of noncovalent interactions. This report describes a series of visualization-based assignments developed to facilitate protein exploration in a large biochemistry class. A large enrollment can present special challenges for students to benefit from hands-on use of visualization software. Three of the assignments are described in detail along with a description of an on-line teaching tool used to manage the assignments and to coordinate the student groups participating in these exercises. [source] Status of Microbial Modeling in Food Process ModelsCOMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, Issue 1 2008Bradley P. Marks ABSTRACT:, Food process models are typically aimed at improving process design or operation by optimizing some physical or chemical outcome, such as maximizing processing yield, minimizing energy usage, or maximizing nutrient retention. However, in seeking to achieve these objectives, one of the critical constraints is usually microbiological. For example, growth of pathogens or spoilage organisms must be held below a certain level, or pathogen reduction for a kill step must achieve a certain target. Therefore, mathematical models for microbial populations subjected to food processing operations are essential elements of the broader field of food process modeling. However, the complexity of the underlying biological phenomena presents special challenges in formulating, validating, and applying microbial models to real-world applications. In that context, the narrow purpose of this article is to (1) outline the general terminology and constructs of microbial models, (2) evaluate the state of knowledge/state of the art in application of these models, and (3) offer observations about current limitations and future opportunities in the area of predictive microbiology for food process modeling. [source] | |||||||||||||||||||||||||||||||