60 resultados para Intellectual and developmental difficulties
Resumo:
Extracts from Piper guineense, Aframomum melegueta, Aframomum citratum and Afrostyrax kamerunensis were investigated for their antifeedant, lethal and developmental effects against Plutella xylostella larvae through laboratory dual-choice tests and topical application. Water and ethanol extracts of P. guineense were dose-dependent antifeedants at concentrations ≥300 and 500 ppm, respectively, whilst methanol extracts required ≥1,000 ppm. Methanol and hexane extracts of A. melegueta acted at ≥100 ppm and water extracts at ≥300 ppm, but ethanol extracts were deterring feeding only slightly at ≥1,000 ppm. Hexane and methanol extracts of A. citratum inhibited feeding at ≥300 ppm and water extracts did so at ≥500 ppm. None of the Afrostyrax kamerunensis extracts deterred feeding at any of the concentrations tested. No mortality was observed at any of the concentrations after topical application of the extracts on the larvae. However, the effects on larval development varied with extract concentration and larval age. Ingestion of the water and ethanol extracts of P. guineense caused 100% mortality of second instars at ≥100 ppm two to three days after infestation (DAI). Methanol and water extracts of A. melegueta and A. citratum, respectively, achieved ≥80% mortality of larvae at concentrations of ≥500 ppm and ≥1,000 ppm, respectively. With third instars, the mortalities were significantly lower; however, the P. guineense water or ethanol extracts caused 100% mortality two to four DAI. Larvae that survived till pupation had significantly longer larval periods compared with the control after application of A. melegueta extracts. We concluded that potent extracts from Aframomum melegueta, Aframomum citratum and especially P. guineense could be used as complementary measures in the management of P. xylostella by subsistence farmers.
Resumo:
Traditionally representation of competencies has been very difficult using computer-based techniques. This paper introduces competencies, how they are represented, and the related concept of competency frameworks and the difficulties in using traditional ontology techniques to formalise them. A “vaguely” formalised framework has been developed within the EU project TRACE and is presented. The framework can be used to represent different competencies and competency frameworks. Through a case study using an example from the IT sector, it is shown how these can be used by individuals and organisations to specify their individual competency needs. Furthermore it is described how these representations are used for comparisons between different specifications applying ontologies and ontology toolsets. The end result is a comparison that is not binary, but tertiary, providing “definite matches”, possible / partial matches, and “no matches” using a “traffic light” analogy.
Resumo:
This paper probes the public dimensions of the work of the twentieth-century Scottish poet W. S. Graham. It draws upon the public contacts and contexts that Graham's lyrics structure and reconfigure, in texts that have appeared to critics to demonstrate the poet's textual aloneness, his intellectual and geographical banishment. Repeatedly addressing his St Ives community of artists and writers, lovers and companions, Graham's work sets up strategic routes through a succession of publicly-minded verbal engagements. Refusing to allow one passively to listen in to the poet's isolation, the lyrics invite, rebuff, tease, avoid, dally with, and proposition audiences and interlocutors. Graham's poetry speaks from within and without tradition, location and heritage, subtly attuning readers to the politics of its handling of national allegiance, identity, class and patronage.
Resumo:
This paper examines the phenomenon of cross-border property lending and examines a number of issues regarding lending procedures and decision making processes in the context of the relationship between lender and professional advisor. It commences by placing these procedures and processes in the context of the development of cross border European property investment and finance. The UK has been a popular destination for overseas investors and lenders over the last decade and is therefore used as a case study to examine the additional institutional risk that overseas lenders may face when operating outside of their own country and obtaining advice from home professionals. The UK market was the subject of a boom period during the late 1980s, followed by a recession in the early 1990s. The losses triggered a number of professional negligence actions by lenders against valuers. These include a number of overseas lenders mainly from Europe and these cases have been examined for any particular features which, coupled with other data gained from overseas lenders as part of an interview survey, could be used to isolate any significant problems for European lenders in overseas markets. The research identified a lack of clarity in roles and relationships between lender and advisor, difficulties in communications both internally and between overseas branches and headquarters and failures in provision and interpretation of advice. The paper concludes by identifying the issues which may need to be addressed generally by lenders and their advisors, when the lenders are operating in overseas markets.
Resumo:
Models which define fitness in terms of per capita rate of increase of phenotypes are used to analyse patterns of individual growth. It is shown that sigmoid growth curves are an optimal strategy (i.e. maximize fitness) if (Assumption 1a) mortality decreases with body size; (2a) mortality is a convex function of specific growth rate, viewed from above; (3) there is a constraint on growth rate, which is attained in the first phase of growth. If the constraint is not attained then size should increase at a progressively reducing rate. These predictions are biologically plausible. Catch-up growth, for retarded individuals, is generally not an optimal strategy though in special cases (e.g. seasonal breeding) it might be. Growth may be advantageous after first breeding if birth rate is a convex function of G (the fraction of production devoted to growth) viewed from above (Assumption 5a), or if mortality rate is a convex function of G, viewed from above (Assumption 6c). If assumptions 5a and 6c are both false, growth should cease at the age of first reproduction. These predictions could be used to evaluate the incidence of indeterminate versus determinate growth in the animal kingdom though the data currently available do not allow quantitative tests. In animals with invariant adult size a method is given which allows one to calculate whether an increase in body size is favoured given that fecundity and developmental time are thereby increased.
Resumo:
Surface-based GPS measurements of zenith path delay (ZPD) can be used to derive vertically integrated water vapor (IWV) of the atmosphere. ZPD data are collected in a global network presently consisting of 160 stations as part of the International GPS Service. In the present study, ZPD data from this network are converted into IWV using observed surface pressure and mean atmospheric water vapor column temperature obtained from the European Centre for Medium-Range Weather Forecasts' (ECMWF) operational analyses (OA). For the 4 months of January/July 2000/2001, the GPS-derived IWV values are compared to the IWV from the ECMWF OA, with a special focus on the monthly averaged difference (bias) and the standard deviation of daily differences. This comparison shows that the GPS-derived IWV values are well suited for the validation of OA of IWV. For most GPS stations, the IWV data agree quite well with the analyzed data indicating that they are both correct at these locations. Larger differences for individual days are interpreted as errors in the analyses. A dry bias in the winter is found over central United States, Canada, and central Siberia, suggesting a systematic analysis error. Larger differences were mainly found in mountain areas. These were related to representation problems and interpolation difficulties between model height and station height. In addition, the IWV comparison can be used to identify errors or problems in the observations of ZPD. This includes errors in the data itself, e.g., erroneous outlier in the measured time series, as well as systematic errors that affect all IWV values at a specific station. Such stations were excluded from the intercomparison. Finally, long-term requirements for a GPS-based water vapor monitoring system are discussed.
Resumo:
The Pax Americana and the grand strategy of hegemony (or “Primacy”) that underpins it may be becoming unsustainable. Particularly in the wake of exhausting wars, the Global Financial Crisis, and the shift of wealth from West to East, it may no longer be possible or prudent for the United States to act as the unipolar sheriff or guardian of a world order. But how viable are the alternatives, and what difficulties will these alternatives entail in their design and execution? This analysis offers a sympathetic but critical analysis of alternative U.S. National Security Strategies of “retrenchment” that critics of American diplomacy offer. In these strategies, the United States would anticipate the coming of a more multipolar world and organize its behavior around the dual principles of “concert” and “balance,” seeking a collaborative relationship with other great powers, while being prepared to counterbalance any hostile aggressor that threatens world order. The proponents of such strategies argue that by scaling back its global military presence and its commitments, the United States can trade prestige for security, shift burdens, and attain a more free hand. To support this theory, they often look to the 19th-century concert of Europe as a model of a successful security regime and to general theories about the natural balancing behavior of states. This monograph examines this precedent and measures its usefulness for contemporary statecraft to identify how great power concerts are sustained and how they break down. The project also applies competing theories to how states might behave if world politics are in transition: Will they balance, bandwagon, or hedge? This demonstrates the multiple possible futures that could shape and be shaped by a new strategy. viii A new strategy based on an acceptance of multipolarity and the limits of power is prudent. There is scope for such a shift. The convergence of several trends—including transnational problems needing collaborative efforts, the military advantages of defenders, the reluctance of states to engage in unbridled competition, and hegemony fatigue among the American people—means that an opportunity exists internationally and at home for a shift to a new strategy. But a Concert-Balance strategy will still need to deal with several potential dilemmas. These include the difficulty of reconciling competitive balancing with cooperative concerts, the limits of balancing without a forward-reaching onshore military capability, possible unanticipated consequences such as a rise in regional power competition or the emergence of blocs (such as a Chinese East Asia or an Iranian Gulf), and the challenge of sustaining domestic political support for a strategy that voluntarily abdicates world leadership. These difficulties can be mitigated, but they must be met with pragmatic and gradual implementation as well as elegant theorizing and the need to avoid swapping one ironclad, doctrinaire grand strategy for another.
Resumo:
This thesis aims to investigate the development and functions of public libraries in Rome and the Roman world. After a preface with maps of libraries in Rome, Section I discusses the precursors for public library provision in the private book collections of Republican Rome, and their transfer into the public domain with the first public libraries of Asinius Pollio and Augustus. Section II contains three 'case studies' of public libraries' different roles. The Augustan library programme is used in Ch.II.l to examine the role of imperial public libraries in literary life and the connections between Rome's libraries and those of Alexandria. Chapter II.2 concentrates on the libraries of Trajan's Forum to explore the intersection of imperial public libraries and monumental public architecture. This chapter responds to an important recent article by arguing for the continued identification of the Forum's libraries with twin brick buildings at its northern end, and suggests a series of correspondences between these libraries and its other monumental components. The conclusions of this chapter are important when considering the public libraries of the wider empire, several of which seem to have been inspired by the Trajanic libraries. Chapter II.3 considers imperial public libraries and leisure by looking at the evidence for libraries within bath-house complexes, concluding that their presence there is consistent with the archaeological and epigraphic evidence and fits in well with what we know of the intellectual and cultural life of these structures. Section III examines various aspects of the practical function of Roman public libraries: their contents (books and archives), division into Latin and Greek sections, provisions for shelving and cataloguing, staff, usership, architectural form, decoration, and housing of works of art. The picture that emerges is of carefully designed and functional buildings intended to sustain public, monumental, and practical functions. Section IV uses a variety of texts to examine the way in which libraries were viewed and used. Ch. IV. 1 discusses the evidence for use of libraries by scholars and authors such as Gellius, Galen, Josephus, and Apuleius. Ch. IV.2 examines parallels between library collections and compendious encyclopaedic elements within Roman literature and considers how library collections came to be canon-forming institutions and vehicles for the expression of imperial approval or disapproval towards authors. The channels through which this imperial influence flowed are investigated in Ch. IV.3, which looks at the directors and staff of the public libraries of Rome. The final section (V) of the thesis concerns public libraries outside the city of Rome. Provincial libraries provide a useful case study in 'Romanisation': they reveal a range of influences and are shown to embody local, personal, and metropolitan imperial identities. There follows a brief conclusion, and a bibliography. There are also five appendices of numismatic and epigraphic material discussed in the text. This material has not been adequately or completely gathered elsewhere and is intended to assist the reader; where appropriate it includes illustrations, transcriptions, and translations.
Resumo:
The transcriptome of an organism is its set of gene transcripts (mRNAs) at a defined spatial and temporal locus. Because gene expression is affected markedly by environmental and developmental perturbations, it is widely assumed that transcriptome divergence among taxa represents adaptive phenotypic selection. This assumption has been challenged by neutral theories which propose that stochastic processes drive transcriptome evolution. To test for evidence of neutral transcriptome evolution in plants, we quantified 18 494 gene transcripts in nonsenescent leaves of 14 taxa of Brassicaceae using robust cross-species transcriptomics which includes a two-step physical and in silico-based normalization procedure based on DNA similarity among taxa. Transcriptome divergence correlates positively with evolutionary distance between taxa and with variation in gene expression among samples. Results are similar for pseudogenes and chloroplast genes evolving at different rates. Remarkably, variation in transcript abundance among root-cell samples correlates positively with transcriptome divergence among root tissues and among taxa. Because neutral processes affect transcriptome evolution in plants, many differences in gene expression among or within taxa may be nonfunctional, reflecting ancestral plasticity and founder effects. Appropriate null models are required when comparing transcriptomes in space and time.
Resumo:
Individuals with Williams syndrome (WS) exhibit striking social behaviour that may be indicative of abnormally low social anxiety. The present research aimed to determine whether social anxiety is unusually low in WS and to replicate previous findings of increased generalised anxiety in WS using both parent and self report. Fifteen individuals with WS aged 12-28 years completed the Spence Children’s Anxiety Scale (SCAS) and the Children’s Automatic Thoughts Scale (CATS). Their responses were compared to clinically anxious and community comparison groups matched on mental age. The findings suggest that WS is not associated with unusually low social anxiety but that generalised anxiety symptoms and physical threat thoughts are increased in WS, relative to typically developing children.
Resumo:
Drawing upon a national database of unimplemented planning permissions and 18 in-depth case studies, this paper provides both a quantitative and qualitative analysis of the phenomenon of stalled sites in England. The practical and conceptual difficulties of classifying sites as stalled are critically reviewed. From the literature, it is suggested that planning permission may not be implemented due to lack of financial viability, strategic behaviour by landowners and house-builders and other problems associated with the development process. Consistent with poor viability, the analysis of the national database indicates that a substantial proportion of the stalled sites is high density apartment development and/or is located in low house value areas. The case studies suggest that a combination of interlinked issues may need to be resolved before a planning permission can be implemented. These include; the sale of the land to house-builders, re-negotiation of the planning permission and, most importantly, improvement in housing market conditions.
Resumo:
According to the weak central coherence (CC) account individuals with autism spectrum disorders (ASD) exhibit enhanced local processing and weak part-whole integration. CC was investigated in the verbal domain. Adolescents, recruited using a 2 (ASD status) by 2 (language impairment status) design, completed an aural forced choice comprehension task involving syntactically ambiguous sentences. Half the picture targets depicted the least plausible interpretation, resulting in longer RTs across groups. These were assumed to reflect local processing. There was no ASD by plausibility interaction and consequently little evidence for weak CC in the verbal domain when conceptualised as enhanced local processing. Furthermore, there was little evidence that the processing of syntactically ambiguous sentences differed as a function of ASD or language-impairment status.
Resumo:
Dystrophin is expressed only in muscle and brain, but is absent from all tissues of the adult mdx mouse, a mutant with a single base substitution in the dystrophin gene. The brains of both normal and mdx mice contain a protein of approximately 230 kDa that is recognised by anti-dystrophin antibodies raised to the N-terminal region of the rod-like domain. Although the N-terminal and central rod regions of dystrophin share structural homologies with spectrin, the 230-kDa protein represents neither of the presently described forms of brain spectrin by a variety of criteria (molecular weight, cerebellar localisation, and developmental regulation) and is distinct from the product of the dystrophin gene. Studies of mdx and normal mouse brain show different postnatal developmental regulation of the 230-kDa dystrophin-immunoreactive protein.
Resumo:
This chapter examines the importance of legitimacy for international organizations, and their efforts to legitimate themselves vis-à-vis different audiences. Legitimacy, which for decades barely featured in the scholarly analysis of international organizations, has since the late 1990s been an increasingly important lens through which the processes, practices, and structures of international organizations have been examined. The chapter makes three main arguments. First, it argues that in most international organizations the most important actors engaging in legitimation efforts are not the supranational bureaucracies, but member states. This has important implications for our understanding of the purposes of seeking legitimacy, and for the possible practices. Second, legitimacy and legitimation serve a range of purposes for these states, beyond achieving greater compliance with their decisions, which has been one of the key functional logics highlighted for legitimacy in the literature. Instead, legitimacy is frequently sought to exclude outsiders from the functional or territorial domains affected by an international organization’s authority, or to maintain external material and political support for existing arrangements. Third, one of the most prominent legitimation efforts, institutional reforms, often prioritizes form over function, signalling to important and powerful audiences to encourage their continued material and political support. To advance these arguments, the chapter is divided into four sections. The first develops the concept of legitimacy and its application to international organizations, and then asks why their legitimacy has become such an important intellectual and political concern in recent years. The second part will look in more detail at the legitimation practices of international organizations, focusing on who engages in these practices, who the key audiences are, and how legitimation claims are advanced. The third section will look in more detail at one of the most common forms of legitimation – institutional reform – through the lens of two such reforms in international organizations: efforts towards greater interoperability in NATO, and the establishment of the African Peace and Security Architecture in the African Union (AU). The chapter will conclude with some reflections of the contribution that a legitimacy perspective has made to our understanding of the practices of international organizations.