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Search Results: 1 - 10 of 6804 matches for " Clarence;Romero "
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A review of evolution of oviposition guilds in the Bruchidae (Coleoptera)
Dan Johnson, Clarence;Romero, Jesús;
Revista Brasileira de Entomologia , 2004, DOI: 10.1590/S0085-56262004000300017
Abstract: three guilds of bruchid beetles oviposit on seeds at different times and in different ways, i. e., in these guilds some species only oviposit on fruits while on the plant (guild a), other species only oviposit on seeds exposed in fruits while still on the plant (guild b) and some only oviposit on seeds once they are exposed on the substrate (guild c). it has been established that one plant species may be oviposited upon by all three guilds, some only by two guilds and some by only one guild. before and after the inception of this concept many papers have been published that seem to establish that early oviposition behavior of bruchids was probably onto fruits where they burrowed through the fruit wall and fed on seeds (guild a). then, as evolution of the fruits developed for dispersal of seeds and possible escape from bruchid predation, bruchids developed to feed in seeds in various other ways (guilds b and c). our data show that about 78% of extant bruchids oviposit on fruits, and the other 22% with behavior of guilds b and c. a review of these papers and new data on oviposition guilds and bruchid evolution are presented and discussed here.
Using Generalizability Theory to Evaluate the Applicability of a Serial Bayes Model in Estimating the Positive Predictive Value of Multiple Psychological or Medical Tests  [PDF]
Clarence D. Kreiter
Psychology (PSYCH) , 2010, DOI: 10.4236/psych.2010.13026
Abstract: Introduction: It is a common finding that despite high levels of specificity and sensitivity, many medical tests are not highly effective in diagnosing diseases exhibiting a low prevalence within a clinical population. What is not widely known or appreciated is how the results of retesting a patient using the same or a different medical or psychological test impacts the estimated probability that a patient has a particular disease. In the absence of a ‘gold standard’ spe-cial techniques are required to understand the error structure of a medical test. Generalizability can provide guid-ance as to whether a serial Bayes model accurately updates the positive predictive value of multiple test results. Methods: In order to understand how sources of error impact a test’s outcome, test results should be sampled across the testing conditions that may contribute to error. A generalizability analysis of appropriately sampled test results should allow researchers to estimate the influence of each error source as a variance component. These results can then be used to determine whether, or under what conditions, the assumption of test independence can be approximately satisfied, and whether Bayes theorem accurately updates probabilities upon retesting. Results: Four hypothetical generalizability study outcomes are displayed as variance component patterns. Each pattern has a different practical implication related to achieving independence between test results and deriving an enhanced PPV through retesting an individual patient. Discussion: The techniques demonstrated in this article can play an important role in achieving an enhanced positive predictive value in medical and psychological diagnostic testing and can help ensure greater confidence in a wide range of testing contexts.
Cladistics, Bruchids and host plants: evolutionary interactions in amblycerus (Coleoptera: Bruchidae)
Jesús Romero Nápoles,Tina J. Ayers,Clarence Dan Johnson
Acta zoológica mexicana , 2002,
Abstract: Se presenta una análisis cladístico preliminar para 40 especies de Amblycerus Thunberg basado en 29 caracteres morfológicos. Se generaron cuatro árboles igualmente parsimoniosos de 60 pasos de longitud, con una consistencia de 0.63 y un índice de retención de 0.88. Remplazando en el cladograma cada una de las especies de Amblycerus por la familia de la planta huésped, fue posible formular una aproximación de la macroevolución en los taxones de los huéspedes. Al parecer estos brúquidos se han movido de la familia de plantas Fabaceae a 12 familias de otras plantas, principalmente Sterculiaceae y Boraginaceae. Varios factores, incluyendo el comportamiento de oviposición, se han citado para explicar algunos de los cambios de huésped. La bioquímica de la planta es especialmente importante, aunque solamente contamos con datos correlativos para soportar estas conclusiones. Para nosotros, la explicación más parsimoniosa sobre los cambios de huésped que observamos es por macroevolución durante ciertos periodos en la diversificación de los brúquidos en la época reciente.
Noun Phrase Cohesion in English Discourse: a Corpus-based Analysis of Patterns and Influences
Clarence Green
International Journal of English Linguistics , 2012, DOI: 10.5539/ijel.v2n4p44
Abstract: This study investigated the patterns of noun phrase cohesion in English discourse, with a specific interest in the role of the different clause types. Using corpus methodology, the study synthesized into a single framework for analysis the central features of previous research regarding cohesive devices, preferred argument structure, genre, information packaging and clause structure. A corpus of 1206 noun phrases was coded for factors drawn from previous research, starting with whether or not the NP contained old/cohesive information. Results of frequency cross-tabulations and a factor analysis indicated that preferred argument structure, noun phrase form, and discourse genre were more significant influences on patterns of noun phrase cohesion in English discourse than clause structure. However, patterns of cohesive noun phrases according to the distance to their antecedents revealed that the more grammatically integrated clauses, such embedded infinitival clauses, the fewer cohesive noun phrases with antecedents in the immediate context they tended to have. This indicated that at the local inter-clausal level noun phrase cohesion and the level of grammatical integration of a combined clause existed in somewhat complementary distribution. Conclusions drawn included that clause grammar codes cohesion locally, displacing the need for noun phrases to mark cohesion in the immediate discourse. The study therefore quantitatively supports previous theories that discourse cohesion and the different types of combined clauses in English exist along a continuum from grammar to discourse.
The end of literature: Reflections on literature and ethics
Clarence Walhout
Koers : Bulletin for Christian Scholarship , 1996, DOI: 10.4102/koers.v61i1.583
Abstract: Metaphysical scepticism and historical consciousness have sharpened our awareness of the limitations of language and rational discourse. This emphasis in critical theory offers a challenge to the Christian literary critic. Reflection on the nature and importance of teleology provides a way of refocusing criticism on the centrality of ethics rather than on truth claims in the study of literature. Using Ricoeur as a counter to the scepticism of Derrida, Christian literary theory can find a way to situate itse lf in the postmodern world. By understanding teleology in the context of narrative theory, as opposed to the contexts of eschatology and utopia, Christian theory can find a way of recovering the place of religion and ethics in literary criticism.
A Computational Investigation of Cohesion and Lexical Network Density in L2 Writing
Clarence Green
English Language Teaching , 2012, DOI: 10.5539/elt.v5n8p57
Abstract: This study used a new computational linguistics tool, the Coh-Metrix, to investigate and measure the differences in cohesion and lexical network density between native speaker and non-native speaker writing, as well as to investigate L2 proficiency level differences in cohesion and lexical network density. This study analyzed data from three corpora with the Coh-Metrix: the International Corpus of Learner English (ICLE) as an L2 higher proficiency group, the Louvain Corpus of Native English Essays (LOCNESS) as a native speaker baseline, and a collected EFL corpus from Indonesia for the L2 lower proficiency data. Statistical investigation of the Coh-Metrix results revealed that five out of six Coh-Metrix variables used in this study did not detect proficiency level differences in L2 but the tool was consistently able to distinguish between L2 and native speaker writing. Differences included that L2 writing contains more argument overlap, more semantic overlap, more frequent content words, fewer abstract verb hyponyms and less causal content than native speaker writing.
Derivative-Based Midpoint Quadrature Rule  [PDF]
Clarence O. E. Burg, Ezechiel Degny
Applied Mathematics (AM) , 2013, DOI: 10.4236/am.2013.41A035

A new family of numerical integration formula is presented, which uses the function evaluation at the midpoint of the interval and odd derivatives at the endpoints. Because the weights for the odd derivatives sum to zero, the derivative calculations cancel out for the interior points in the composite form, so that these derivatives must only be calculated at the endpoints of the overall interval of integration. When using N subintervals, the basic rule which uses the midpoint function evaluation and the first derivative at the endpoints achieves fourth order accuracy for the cost of N/2 function evaluations and 2 derivative evaluations, whereas the three point open Newton-Cotes method uses 3N/4 function evaluations to achieve the same order of accuracy. These derivative-based midpoint quadrature methods are shown to be more computationally efficient than both the open and closed Newton-Cotes quadrature rules of the same order. This family of derivative-based midpoint quadrature rules are derived using the concept of precision, along with the error term. A theorem concerning the order of accuracy of quadrature rule using the concept of precision is provided to justify its use to determine the leading order error term.

Evaluation of the Swedish breeding program for cavalier King Charles spaniels
Tobias Lundin, Clarence Kvart
Acta Veterinaria Scandinavica , 2010, DOI: 10.1186/1751-0147-52-54
Abstract: Mitral regurgitation (MR), secondary to myxomatous mitral valve disease (MMVD), is the most common cardiac disorder in dogs and is usually caused by progressive degeneration of the atrioventricular valves. Degeneration of the atrioventricular valves renders the leaflets thicker and irregular, leading to insufficient coaptation of the leaflets and regurgitation of blood with accompanying enlargement of the atria and ventricles. These pathological changes are associated with a characteristic systolic heart murmur when the valves become incompetent and blood is ejected back into the atrium during systole. The mitral valve alone or both the mitral and tricuspid valves may be affected: the tricuspid valve alone, aortic, or pulmonary valves are less commonly affected. The dog can compensate for valvular insufficiency for a period, but with progression of valve degeneration, usually left side, congestive heart failure ultimately develops. MMVD is found in all dogs but is more common in small to medium-size breeds, such as Poodle, Papillon, Dachshund, Chihuahua and CKCS [1,2]. In CKCS onset is early with a high prevalence of MR caused by MMVD, and at the age of 6-7 years, murmur prevalence is approximately 50%. At the age of 11 years, almost 100% of CKCS have developed MMVD [3-8].MMVD is considered highly inheritable with a polygenic threshold, which means that multiple genes influence the trait and a certain threshold has to be reached before MMVD and MR develops [9,10]. Males have a lower threshold than females, meaning in a population of dogs with the same genotype, male dogs will develop MMVD at a lower age than females. If two dogs with late onset MMVD mate, the offspring will, on average, have late onset MMVD, and vice versa [10].Based on this knowledge, the Swedish Kennel club and the Special club for cavalier King Charles spaniels (SCKCS) started a breeding program in 2001 with the aim of reducing MMVD in the Swedish population of CKCS. In this program, dogs are not
Migration and health: fact, fiction, art, politics
Clarence C Tam
Emerging Themes in Epidemiology , 2006, DOI: 10.1186/1742-7622-3-15
Abstract: "Therefore is the name of it called Babel; because the Lord did there confound the language of all the earth: and from thence did the Lord scatter them abroad upon the face of all the earth."Genesis 11: 9.The Whitney Museum of American Art in New York recently held its Biennial 2006 exhibition [1]. Entitled Day for Night, after the Truffaut film in which scenes shot in daylight are made to imply night-time, the exhibition was guided by themes of ambiguity, in the literal (works that are not quite what they appear to be), conceptual (in deconstructing the role of the artist in the current socio-political climate) and practical senses (in trying to define what actually constitutes "American" art). The 2006 Biennial was heavily influenced by the work of appropriationists, artists reclaiming everyday objects to create artistic statements. In that vein, I have "appropriated" three objects of my own in this discussion about migration: one artistic (Mark Bradford's Los Moscos), one literary (Upton Sinclair's The Jungle), and one political (the proposed Immigration Bills currently under consideration in the United States Congress). These three objects make different comments on migration – specifically worker migration – and provide "extra-scientific" perspectives that reveal certain causal truths not immediately apparent from a purely scientific approach. This essay focuses on the intersection between migration and health not to comment on the health of migrant workers, but rather to argue that the issue of migrant health is merely a symptom of a much wider socio-political discussion, from which the public health community is noticeably absent, but in which it must engage if the rights of those most affected by current social and political trends are to be protected. I first describe each of my three appropriations in turn and subsequently comment on the implications for the public health community. Although I focus on the United States (US) context – the source of my thre
The birth of Emerging Themes in Epidemiology: a tale of Valerie, causality and epidemiology
Clarence C Tam
Emerging Themes in Epidemiology , 2004, DOI: 10.1186/1742-7622-1-1
Abstract: "Causality. There is no escape from it, we are forever slaves to it. Our only hope, our only peace is to understand it, to understand the 'why'[1]."- The MerovingianAs far as we know, the Wachowski brothers' Merovingian was not an epidemiologist, but his sentiments should resonate well with those in the field. Probably more than those in any other profession, epidemiologists are slaves to causality. Our professional lives are dedicated to the pursuit of pumphandles, spiderwebs and causal pies [2,3]. Adding to these colourful metaphors are ones proposing frameworks for epidemiologic research that involve Chinese boxes, computer-generated fractals and prison breaks [2,4,5]. But what is the student of epidemiology to make of all these curious abstractions? Lost in a sea of metaphors, they might very likely throw their arms up in the air and, in thorough confusion, decide to take a long and much-needed coffee break [6-8].The epidemiologic literature on causality certainly makes for stimulating reading, but it would be interesting to know how many of us have causal pies and fractals on our minds as we reach for that red folder labelled "Logistic regression 101". Discursive articles on the usefulness of such metaphors are widely regarded as philosophical flights of fancy that we might eventually get around to reading after clearing that backlog of papers waiting to be written in the next two months. Yet what are our alternatives? The newly-qualified epidemiologist leaves their degree with a solid grasp of error, bias, confounding and statistical methodology, but with perhaps a single lecture on Koch-Henlé postulates and Bradford-Hill 'criteria' as the extent of their training into causal thinking. It is interesting to note that Last's Dictionary of Epidemiology does not include the term 'cause', opting instead to give a definition of 'causality' that involves a brief discussion of necessity and sufficiency [9]. Any reasoned assessment will quickly lead to the conclusion t
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