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Categorization
Kinds of Categorization Terms modified by Categorization Selected AbstractsAN EFFICIENT MODEL FOR ENHANCING TEXT CATEGORIZATION USING SENTENCE SEMANTICSCOMPUTATIONAL INTELLIGENCE, Issue 3 2010Shady Shehata Most of text categorization techniques are based on word and/or phrase analysis of the text. Statistical analysis of a term frequency captures the importance of the term within a document only. However, two terms can have the same frequency in there documents, but one term contributes more to the meaning of its sentences than the other term. Thus, the underlying model should identify terms that capture the semantics of text. In this case, the model can capture terms that present the concepts of the sentence, which leads to discovering the topic of the document. A new concept-based model that analyzes terms on the sentence, document, and corpus levels rather than the traditional analysis of document only is introduced. The concept-based model can effectively discriminate between nonimportant terms with respect to sentence semantics and terms which hold the concepts that represent the sentence meaning. A set of experiments using the proposed concept-based model on different datasets in text categorization is conducted in comparison with the traditional models. The results demonstrate the substantial enhancement of the categorization quality using the sentence-based, document-based and corpus-based concept analysis. [source] Correlations among Extinction Risks Assessed by Different Systems of Threatened Species CategorizationCONSERVATION BIOLOGY, Issue 6 2004JULIAN J. O'GRADY análisis de viabilidad poblacional; categorías de amenaza; especies en peligro; riesgo de extinción Abstract:,Many different systems are used to assess levels of threat faced by species. Prominent ones are those used by the World Conservation Union, NatureServe, and the Florida Game and Freshwater Fish Commission (now the Florida Fish and Wildlife Conservation Commission). These systems assign taxa a threat ranking by assessing their demographic and ecological characteristics. These threat rankings support the legislative protection of species and guide the placement of conservation programs in order of priority. It is not known, however, whether these assessment systems rank species in a similar order. To resolve this issue, we assessed 55 mainly vertebrate taxa with widely differing life histories under each of these systems and determined the rank correlations among them. Moderate, significant positive correlations were seen among the threat rankings provided by the three systems (correlations 0.58,0.69). Further, the threat rankings for taxa obtained using these systems were significantly correlated to their rankings based on predicted probability of extinction within 100 years as determined by population viability analysis (correlations 0.28,0.37). The different categorization systems, then, yield related but not identical threat rankings, and these rankings are associated with predicted extinction risk. Resumen:,Se utilizan muchos sistemas diferentes para evaluar los niveles de amenaza que enfrentan las especies. Son prominentes los utilizados por World Conservation Union, NatureServe Heritage y Florida Game and Freshwater Fish Commission (ahora Florida Fish and Wildlife Conservation Commission). Estos sistemas asignan una categoría de amenaza a los taxa mediante la evaluación de sus características demográficas y ecológicas. Estas categorías de amenaza sustentan a la protección legislativa de especies y guían la definición de prioridades en programas de conservación. Sin embargo, se desconoce si estos sistemas de evaluación categorizan a las especies en orden similar. Para resolver este tema, evaluamos 55 taxa, principalmente de vertebrados, con historias de vidas muy diferentes con cada uno de estos sistemas y determinamos las correlaciones entre las categorías. Hubo correlaciones positivas moderadas entre las categorías de amenaza proporcionadas por los tres sistemas (correlaciones 0.58-0.69). Más aun, las categorías de amenaza proporcionados por estos sistemas estuvieron correlacionadas significativamente con las categorías definidas con base en la probabilidad de extinción pronosticada en 100 años determinada por análisis de viabilidad poblacional (correlaciones 0.28-0.37). Por lo tanto, los diferentes sistemas de categorización están proporcionando categorías de amenazas relacionadas pero no idénticas, y estas categorías están relacionadas con el riesgo de extinción pronosticado. [source] The relationship between baseline value and its change: problems in categorization and the proposal of a new methodEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 4 2005Yu-Kang Tu Oral health researchers have shown great interest in the relationship between the initial status of diseases and subsequent changes following treatment. Two main approaches have been adopted to provide evidence of a positive association between baseline values and their changes following treatment. One approach is to use correlation or regression to test the relationship between baseline measurements and subsequent change (correlation/regression approach). The second approach is to categorize the lesions into subgroups, according to threshold values, and subsequently compare the treatment effects across the two (or more) subgroups (categorization approach). However, the correlation/regression approach suffers a methodological weakness known as mathematical coupling. Consequently, the statistical procedure of testing the null hypothesis becomes inappropriate. Categorization seems to avoid the problem of mathematical coupling, although it still suffers regression to the mean. We show, first, how the appropriate null hypothesis may be established to analyze the relationship between baseline values and change in the correlation approach and, second, we use computer simulations to investigate the impact of regression to the mean on the significance testing of the differences in the average treatment effects (or average baseline values) in the categorization approach. Data available from previous literature are reanalyzed by testing the appropriate null hypotheses and the results are compared to those from testing the usual (incorrect) null hypothesis. The results indicate that both the correlation and categorization approaches can give rise to misleading conclusions and that more appropriate methods, such as Oldham's method and our new approach of deriving the correct null hypothesis, should be adopted. [source] Categorization is not the only way: a comment on Rodrigo and AtoEUROPEAN JOURNAL OF SOCIAL PSYCHOLOGY, Issue 1 2002Henk A. L. Kiers First page of article [source] Role of Chronic Infection and Inflammation in the Gastrointestinal Tract in the Etiology and Pathogenesis of Idiopathic ParkinsonismHELICOBACTER, Issue 4 2005Part 1: Eradication of Helicobacter in the Cachexia of Idiopathic Parkinsonism ABSTRACT Background., Neuronal damage in idiopathic parkinsonism may be in response to ubiquitous occult infection. Since peptic ulceration is prodromal, Helicobacter is a prime candidate. Aim., To consider the candidature of Helicobacter in parkinsonism with cachexia. Methods., We explore the relationship between being underweight and inflammatory products in 124 subjects with idiopathic parkinsonism and 195 controls, and present the first case-series evidence of efficacy of Helicobacter eradication, in parkinsonism advanced to the stage of cachexia. Results., Association of a low body mass index with circulating interleukin-6 was specific to parkinsonism (p = .002), unlike that with antibodies against Helicobacter vacuolating-toxin and cytotoxicity-associated gene product (p < .04). Marked reversibility in both cachexia and disability of idiopathic parkinsonism followed Helicobacter heilmannii eradication in one case, Helicobacter pylori eradication in another, follow-up being , 3.5 years. The latter presented with postprandial bloating, and persistent nausea: following eradication, radioisotope gastric-emptying returned towards normal, and upper abdominal symptoms regressed. Reversibility of their cachexia/disability contrasts with the outcome of anti- Helicobacter therapy where eradication repeatedly failed (one case), and in non- Helicobacter gastritis (three cases). Anti-parkinsonian medication remained constant. Intestinal absorption and barrier function were normal in all. Conclusion., Categorization, according to presence or absence of Helicobacter infection, was a useful therapeutic tool in late idiopathic parkinsonism. [source] Thermal Rearrangements of Monoterpenes and MonoterpenoidsHELVETICA CHIMICA ACTA, Issue 9 2009Achim Stolle Abstract The thermal conversions of monoterpenes and monoterpenoids are an interesting field of research with respect to mechanistic, kinetic, and theoretical issues. Since the beginning of the 20th century, these reactions have attracted the interest of many research groups, and even today there are sufficient problems and questions to deal with. This review covers the thermal isomerization chemistry of pinanes, pinenes, carenes, and thujenes over the past 70 years. Categorization of these compounds into groups, each of them being represented by a small parent molecule (cyclobutane, vinylcyclobutane, vinylcyclopropane), allows systematization of multitude of publications. [source] Neural bases of categorization of simple speech and nonspeech soundsHUMAN BRAIN MAPPING, Issue 8 2006Fatima T. Husain Abstract Categorization is fundamental to our perception and understanding of the environment. However, little is known about the neural bases underlying the categorization of sounds. Using human functional magnetic resonance imaging (fMRI) we compared the brain responses to a category discrimination task with an auditory discrimination task using identical sets of sounds. Our stimuli differed along two dimensions: a speech,nonspeech dimension and a fast,slow temporal dynamics dimension. All stimuli activated regions in the primary and nonprimary auditory cortices in the temporal cortex and in the parietal and frontal cortices for the two tasks. When comparing the activation patterns for the category discrimination task to those for the auditory discrimination task, the results show that a core group of regions beyond the auditory cortices, including inferior and middle frontal gyri, dorsomedial frontal gyrus, and intraparietal sulcus, were preferentially activated for familiar speech categories and for novel nonspeech categories. These regions have been shown to play a role in working memory tasks by a number of studies. Additionally, the categorization of nonspeech sounds activated left middle frontal gyrus and right parietal cortex to a greater extent than did the categorization of speech sounds. Processing the temporal aspects of the stimuli had a greater impact on the left lateralization of the categorization network than did other factors, particularly in the inferior frontal gyrus, suggesting that there is no inherent left hemisphere advantage in the categorical processing of speech stimuli, or for the categorization task itself. Hum Brain Mapp, 2005. © 2005 Wiley-Liss, Inc. [source] Linguistic Labels and Categorization in Infancy: Do Labels Facilitate or Hinder?INFANCY, Issue 3 2007Christopher W. Robinson Although it is generally accepted that labels facilitate categorization in infancy, recent evidence suggests that infants and young children are more likely to process visual input when presented in isolation than when paired with nonlinguistic sounds or linguistic labels. These findings suggest that auditory input (when compared to a no-auditory baseline) may hinder rather than facilitate categorization. This study assessed 8-month-olds' (n = 191) and 12-month-olds' (n = 81) abilities to form categories when images were paired with nonlinguistic sounds, linguistic labels, and when presented in isolation. Overall, infants accumulated more looking when visual stimuli were accompanied by sounds or labels; however, infants were more likely to categorize when the visual images were presented without an auditory stimulus. [source] A Comparison of Visual Familiarization and Object-Examining Measures of Categorization in 9-Month-Old InfantsINFANCY, Issue 3 2003Barbara A. Younger Three studies were conducted to determine whether differential patterns of categorization observed in studies using visual familiarization and object-examining measures hold up as procedural confounds are eliminated. In Experiment 1, we attempted as direct a comparison as possible between visual and object-examining measures of categorization. Consistent with previous reports, 9-month-old infants distinguished a basic-level contrast (dog,horse) in the visual task, but not in the examining task. Experiment 2 was designed to reduce levels of nonexploratory activity in an examining task; 9-month-olds again failed to distinguish categories of dogs and horses. In Experiment 3, we adopted a paired-comparison test format in the object-examining task. Infants did display a novel category preference under paired testing conditions. The results suggest that the different patterns of categorization often seen in looking and touching tasks are a reflection, not of different categorization processes, but of the differential sensitivity of the tasks. [source] The Influence of Labels, Non-Labeling Sounds, and Source of Auditory Input on 9- and 15-Month-Olds' Object CategorizationINFANCY, Issue 3 2003Anne L. Fulkerson This experiment examines the joint influence of auditory and social cues on infants' basic-level and global categorization. Nine- and fifteen-month-olds were familiarized to a series of category exemplars in an object-examining task. Objects were introduced with a labeling phrase, a non-labeling sound, or no sound, and auditory input was presented orally by the experimenter or played on a hidden voice recorder. Novel objects from the familiarized category and a contrasting category were then presented. Results of analyses performed on novelty preference scores indicated that infants demonstrated basic-level categorization in all conditions. However, infants at both age levels only demonstrated global categorization when labeling phrases were introduced. In addition, labels led to global categorization in 9-month-olds regardless of the source of those labels; however, labels only led to global categorization in 15-month-olds when the labels were presented orally by the experimenter. [source] Quasilocal defects in regular planar networks: Categorization for molecular conesINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 4-5 2003D. J. Klein Abstract Graphical networks are cast into structural equivalence classes, with special focus on ones related to two-dimensional regular translationally symmetric nets (or lattices). A quasilocal defect in a regular net is defined as consisting of a finite subnet surrounded outside this region by an infinitely extended network of which arbitrary, simply connected regions are isomorphic to those of the regular undefected net. The global equivalence classes for such quasilocal defects are identified by a "circum-matching" characteristic. One or more such classes are identified as a "turn" number, or equivalently as a discrete "combinatorial curvature" ,, which associates closely to the geometric Gaussian curvature of "physically reasonable" embeddings of the net in Euclidean space. Then for positive ,, geometric cones result; for , = 0, the network is flat overall; and for negative ,, fluted or crenalated cones result. As , or q varies through its discrete range, the number of defect classes varies between 1 and , and repeats with a period depending on the parent regular net. For the square-planar net, the numbers of defect classes at succeeding turn numbers (q) starting at q = 0 are ,, 2, 3, 2, repeating with a period of 4. For the hexagonal and triangular nets, the numbers of classes at suceeding q starting at q = 0 are ,, 1, 2, 2, 2, 1, repeating with a period of 6. A further refinement of the classes of quasilocal defects breaks these classes up into "irrotational" subclasses, as are relevant for multiwall cones. The subclasses are identified via a "quasispin" characteristic, which is conveniently manipulatable for the categorization of multiwall cones. Besides the development of the overall comprehensive topo-combinatoric categorization scheme for quasilocal defects, some consequences are briefly indicated, and combining rules for the characteristics of pairs of such defects are briefly considered. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2003 [source] Copyright Protection for Computer Programs in South Africa: Aspects of Sui Generis CategorizationTHE JOURNAL OF WORLD INTELLECTUAL PROPERTY, Issue 4 2009Lee-Ann Tong This article considers the protection of computer software in South Africa. It deals specifically with copyright of computer programs as provided for in the Copyright Act 98 of 1978 which makes provision for the categorization of computer programs as a sui generis category of works distinct from literary works. It explores the level of copyright protection under this regime with reference to aspects like the subsistence of copyright, authorship, ownership, duration, moral rights and infringement. It also considers the effect of the sui generis categorization on compliance with the Agreement on Trade-Related Aspects of Intellectual Property Rights and the anomalies that arise in the protection of preparatory work and computer programs. The focus is primarily on South African law. [source] Sex Categorization Among Preschool Children: Increasing Utilization of Sexually Dimorphic CuesCHILD DEVELOPMENT, Issue 5 2010Kerri L. Johnson Two studies examined how children between ages 4 and 6 use body shape (i.e., the waist-to-hip-ratio [WHR]) for sex categorization. In Study 1 (N = 73), 5- and 6-year-olds, but not 4-year-olds, selected bodies with increasingly discrepant WHRs to be "most like a man" and "most like a woman." Similarly, sex category judgments made by 5- and 6-year-olds, but not 4-year-olds, varied with WHR. In Study 2 (N = 41), eye movements indicated the functional use of waist and hips in sex categorization. Visual scanning behavior predicted the degree of association between WHR and judgment. Collectively, these results suggest that the ability to exploit sexual dimorphism to compel categorization develops between the ages of 4 and 6. Implications for theories of gender development and psychological essentialism are discussed. [source] Do Novel Words Facilitate 18-Month-Olds' Spatial Categorization?CHILD DEVELOPMENT, Issue 6 2007Marianella Casasola Eighteen-month-olds' spatial categorization was tested when hearing a novel spatial word. Infants formed an abstract categorical representation of support (i.e., placing 1 object on another) when hearing a novel spatial particle during habituation but not when viewing the events in silence. Infants with a productive spatial vocabulary did not discriminate the support relation when hearing the same novel word as a count noun. However, infants who were not yet producing spatial words did attend to the support relation when presented with the novel count noun. The results indicate that 18-month-olds can use a novel particle (possibly assisted by a familiar verb) to facilitate their spatial categorization but that the specificity of this effect varies with infants' acquisition of spatial language. [source] Flexible and Context-Dependent Categorization by Eighteen-Month-OldsCHILD DEVELOPMENT, Issue 1 2007Denis Mareschal One hundred 18-month-olds were tested using sequential touching and following 4 different priming contexts using sets of toys that could be simultaneously categorized at either the basic or global level. An exact expression of the expected mean sequence length for arbitrary categories was derived as a function of the number of touches made, and a finite mixture model analytic method was also used to explore individual variability in categorization. Toddlers could categorize flexibly and spontaneously selected the level of categorization as a function of the prior prime. Perceptual Variability emerged as a predictor of the level at which infants subsequently categorized. The infants were also able to classify objects as members of both basic- and global-level categories simultaneously. [source] Preschool Children's Attention to Environmental Messages About Groups: Social Categorization and the Origins of Intergroup BiasCHILD DEVELOPMENT, Issue 4 2006Meagan M. Patterson This study was designed to examine the effects of adults' labeling and use of social groups on preschool children's intergroup attitudes. Children (N=87, aged 3,5) attending day care were given measures of classification skill and self-esteem and assigned to membership in a novel ("red" or "blue") social group. In experimental classrooms, teachers used the color groups to label children and organize the classroom. In control classrooms, teachers ignored the color groups. After 3 weeks, children completed multiple measures of intergroup attitudes. Results indicated that children in both types of classrooms developed ingroup-biased attitudes. As expected, children in experimental classrooms showed greater ingroup bias on some measures than children in control classrooms. [source] Development of Subordinate-Level Categorization in 3- to 7-Month-Old InfantsCHILD DEVELOPMENT, Issue 3 2004Paul C. Quinn Visual preference procedures were used to investigate development of perceptually based subordinate-level categorization in 3- to 7-month-old infants. Experiments 1 and 2 demonstrated that 3- to 4-month-olds did not form category representations for photographic exemplars of subordinate-level classes of cats and dogs (i.e., Siamese vs. Tabby, Beagle vs. Saint Bernard). Experiments 3 though 5 showed that 6- and 7-month-olds formed a category representation for Tabby that excluded Siamese and a category representation for Saint Bernard that excluded Beagle, but they did not form a category representation for Siamese that excluded Tabby or a category representation for Beagle that excluded Saint Bernard. The findings are consistent with a differentiation-driven view of early perceptual category development from global to basic to subordinate levels. [source] Six-Month-Old Infants' Categorization of Containment Spatial RelationsCHILD DEVELOPMENT, Issue 3 2003Marianella Casasola Six-month-old infants' ability to form an abstract category of containment was examined using a standard infant categorization task. Infants were habituated to 4 pairs of objects in a containment relation. Following habituation, infants were tested with a novel example of the familiar containment relation and an example of an unfamiliar relation. Results indicate that infants look reliably longer at the unfamiliar versus familiar relation, indicating that they can form a categorical representation of containment. A second experiment demonstrated that infants do not rely on object occlusion to discriminate containment from a support or a behind spatial relation. Together, the results indicate that by 6 months, infants can recognize a containment relation from different angles and across different pairs of objects. [source] A Restoratively Driven Ridge Categorization, as Determined by Incorporating Ideal Restorative Positions on Radiographic Templates Utilizing Computed Tomography Scan AnalysisCLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 4 2009Nicolas Elian DDS ABSTRACT Background: The introduction of implants into the field of dentistry has revolutionized the way we evaluate edentulous ridges. In an attempt to evaluate the deficient edentulous ridge, numerous classification systems have been proposed. Each of these classification systems implements a different approach for evaluating and planning treatment for the ridge deficiency. Purpose: The purpose of the present investigation was to propose a restoratively driven ridge categorization (RDRC) for horizontal ridge deformities based on an ideal implant position as determined through implant simulation, utilizing computed tomography (CT) scan images. Materials and Methods: Radiographic templates were developed to capture the ideal restorative tooth position. Measurements were performed using CT scan software in a cross-sectional view and by virtual placement of a parallel-sided implant with a 3.25-mm diameter. Results: Edentulous ridges were divided into five groupings: Group I, simulated implants with at least 2 mm of facial bone, accounted for 19.4% of ridges; Group II, simulated implant completely surrounded by bone, with less than 2 mm of facial plate thickness, accounted for 10.4% of ridges; Group III, wherein dehiscences are detected but no fenestrations are present, accounted for 33.3% of ridges; Group IV, wherein fenestrations are detected but no dehiscence is present, accounted for 6.3% of ridges; and Group V, wherein both dehiscences and fenestrations are present, accounted for 30.6% of ridges. Conclusion: The use of RDRC indicates that a high number of cases in the maxillary anterior area would require augmentation procedures in order to achieve ideal implant placement and restoration. [source] Categorization as causal reasoning,COGNITIVE SCIENCE - A MULTIDISCIPLINARY JOURNAL, Issue 5 2003Bob Rehder Abstract A theory of categorization is presented in which knowledge of causal relationships between category features is represented in terms of asymmetric and probabilistic causal mechanisms. According to causal-model theory, objects are classified as category members to the extent they are likely to have been generated or produced by those mechanisms. The empirical results confirmed that participants rated exemplars good category members to the extent their features manifested the expectations that causal knowledge induces, such as correlations between feature pairs that are directly connected by causal relationships. These expectations also included sensitivity to higher-order feature interactions that emerge from the asymmetries inherent in causal relationships. Quantitative fits of causal-model theory were superior to those obtained with extensions to traditional similarity-based models that represent causal knowledge either as higher-order relational features or "prior exemplars" stored in memory. [source] Categorization of major and minor complications in the treatment of patients with resectable rectal cancer using short-term pre-operative radiotherapy and total mesorectal excision: a Delphi roundCOLORECTAL DISEASE, Issue 4 2006R. Bakx Abstract Background, To properly balance the benefit (reduction of local recurrence) of short-term pre-operative radiotherapy for resectable rectal cancer against its harm (complications), a consensus concerning the severity of complications is required. The aim of this study was to reach consensus regarding major and minor complications after short-term radiotherapy followed by total mesorectal excision in the treatment of rectal carcinoma, using the Delphi technique. Methods, A Delphi round was performed in cooperation with 21 colo-rectal surgeons from the Netherlands, United Kingdom and Sweden. The key-question was: ,Which of the predefined complications, caused or substantially aggravated by radiotherapy, are so important (major) that they might lead to the decision to abandon short-term pre-operative radiotherapy (5 × 5Gy) when treating patients with resectable rectal cancer (T1,3N0,2M0)?' Results, After three rounds, consensus was reached for 37 (68%) of 54 complications of which 13 were considered major and 24 considered minor. The following complications were considered to be major: mortality, anastomotic leakage managed by relaparotomy, anastomotic leakage resulting in persisting fistula, postoperative haemorrhage managed by relaparotomy, intra-abdominal abscess without healing tendency, sepsis, pulmonary embolism, myocardial infarction, compartment syndrome of the lower legs, long-term incontinence for solid stool, long-term problems with voiding, pelvic fracture with persisting pain, and neuropathy with persisting pain (legs). Three of 17 complications without consensus showed a tendency to be considered as major: perineal wound dehiscence managed by surgical treatment, small bowel obstruction leading to relaparotomy and long-term incontinence for liquid stool. Conclusion, The 13 major and three ,accepted as major' complications can be used to properly balance the benefit and harm of short-term pre-operative radiotherapy in resectable rectal cancer. This may eventually lead to improved treatment strategies for these patients. [source] A method-level comparison of the Java Grande and SPEC JVM98 benchmark suitesCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 7-8 2005David Gregg Abstract In this paper we seek to provide a foundation for the study of the level of use of object-oriented techniques in Java programs in general, and scientific applications in particular. Specifically, we investigate the profiles of Java programs from a number of perspectives, including the use of class library methods, the size of methods called, the mode of invoke instruction used and the polymorphicity of call sites. We also present a categorization of the nature of small methods used in Java programs. We compare the Java Grande and SPEC JVM98 benchmark suites, and note a significant difference in the nature and composition of these suites, with the programs from the Java Grande suite demonstrating a less object-oriented approach. Copyright © 2005 John Wiley & Sons, Ltd. [source] Temporal Extrapolation of PVA Results in Relation to the IUCN Red List Criterion ECONSERVATION BIOLOGY, Issue 1 2003Oskar Kindvall For a population viability analysis ( PVA) to be useful for assessing a species' threat category, the results must have been expressed as the full extinction probability function over time or at least for the three specified time frames. Often this is not the case, and extrapolations from different kinds of PVA results ( e.g., mean time to extinction ) are often necessary. By means of analytic models, we investigated the possibilities of extrapolation. Based on our results, we suggest that extrapolation is not advisable due to the huge errors that can occur. The extinction probability function is the best kind of summary statistic to use when applying criterion E, but even then the threat categorization may be ambiguous. If the extinction risk is low in the near future but increases rapidly later on, a species may be classified as vulnerable even though it is expected to become extinct within 100 years. To avoid this, we suggest that the guidelines to the IUCN Red List criteria include three reference lines that allow for interpretation of the PVA results in the context of the three threat categories within the entire period of 100 years. If the estimated extinction probability function overshoots one of these functions, the species should be classified accordingly. Resumen: Las categorías de amenaza de la lista roja de la IUCN ( críticamente en peligro, en peligro y vulnerable ) están definidos por un juego de criterios ( A-E ). El criterio E se define cuantitativamente por tres límites especificados de riesgo de extinción ( 50%, 20% y 10% ), cada uno de los cuales se asocia a un marco temporal determinado. Para poder usar el análisis de viabilidad poblacional ( PVA ) durante la evaluación de la categoría de amenaza de una especie, los resultados deben ser expresados en función de probabilidad de extinción total sobre un tiempo o al menos para los tres marcos temporales especificados. Frecuentemente este no es el caso y las extrapolaciones de diferente tipo de resultados de PVA ( tiempo promedio de extinción ) son usualmente necesarias. Por medio de modelos analíticos investigamos las posibilidades de extrapolación. En base a nuestros resultados sugerimos que la extrapolación no es recomendable debido a una enorme cantidad de errores que pueden ocurrir. La función de probabilidad de extinción es el mejor tipo de resumen estadístico a usar cuando se aplica el criterio E, pero, aún así, la categorización de amenaza puede ser ambigua. Si el riesgo de extinción es bajo en un futuro inmediato pero incrementa muy rápidamente después, una especie puede ser clasificada como vulnerable aunque se espere que se extinga dentro de los próximos 100 años. Para evitar esto, sugerimos que los lineamientos de los criterios de la Lista Roja de la UICN incluyan tres lineas de referencia que permitan la interpretación de los resultados del PVA en el contexto de las tres categorías dentro de un periodo completo de 100 años. Si la función de probabilidad de extinción estimada se extiende más allá de una de estas funciones, las especies deberán ser clasificadas según sea el caso. [source] Cytomorphological study of soft tissue neoplasms: role of fluorescent immunocytochemistry in diagnosisCYTOPATHOLOGY, Issue 5 2005B. Rekhi Objectives:, Exact categorization of soft tissue tumours (STTs) on smears requires application of various ancillary techniques. This study was aimed at evaluating the role of fluorescent immunocytochemistry (FICC) in cyto-diagnosis of 30 STT cases. Methods:, Thirty cases of soft tissue tumours were included in the present study. All cases were subjected to routine Giemsa and Papanicolaou stain. Extra smears were made and kept for fluorescent immunostaining. A panel of cytoskeletal antibodies, tagged with FITC (Fluorescein isothyocynate), was employed in all these cases. Fluorescent immunostained smears were examined under Zeiss Confocal Laser scanning microscope, using double immunofluorescence (red-green). Finally, all cases were subjected to biopsy and again immunoperoxidase staining. Results:, Among the 30 cases in the present study, unaided cytological diagnoses ranged from ,spindle cell' tumour in four (13.3%) cases, benign and malignant spindle cell tumour in 17 (56.6%) cases, to malignant mesenchymal tumour in nine (30%) cases. FICC helped in further correct categorization of 25/30 (83.3%) cases viz. leiomyoma (three), benign neurogenic tumour (six), schwannoma (one), dermatofibrosarcoma protuberans (three), synovial sarcoma (two), rhabdomyosarcoma (two), malignant fibrous histiocytoma (five) and malignant peripheral nerve sheath tumour (three). Aggressive fibromatosis was found to be a missed diagnosis in two cases. Overall concordance between cyto-diagnosis with FICC, and histopathology results was 83.3% (P < 0.05). Conclusion:, Fluorescent immunocytochemistry is a significant ancillary technique for making a rapid and specific diagnosis of STT, as required for their timely management. Incorporation of a wide panel of antibody markers with clinico-cytological correlation is recommended in forming an exact diagnosis in these cases. [source] An evidence-based appraisal of splinting luxated, avulsed and root-fractured teethDENTAL TRAUMATOLOGY, Issue 1 2008Bill Kahler For this systematic review of splinting of teeth that have been luxated, avulsed or root-fractured, the clinical PICO question is (P) what are splinting intervention decisions for luxated, avulsed and root-fractured teeth (I) considering that the splinting intervention choice may include (i) no splinting, (ii) rigid or functional splinting for the different types of trauma and (iii) different durations of the splinting period (C) when comparing these splinting choices for the different types of trauma and their effect on (O) healing outcomes for the teeth. A keyword search of PubMed was used. Reference lists from identified articles and dental traumatology texts were also appraised. The inclusion criterion for this review was either a multivariate analysis or controlled stratified analyses as many variables have the potential to confound the assessment and evaluation of healing outcomes for teeth that have been luxated, avulsed or root-fractured. A positive statistical test is not proof of a causal conclusion, as a positive statistical relationship can arise by chance, and so this review also appraises animal studies that reportedly explain biological mechanisms that relate to healing outcomes of splinted teeth. The clinical studies were ranked using the ,Centre of Evidence-based Medicine' categorization (levels 1,5). All 12 clinical studies selected were ranked as level 4. The studies generally indicate that the prognosis is determined by the type of injury rather than factors associated with splinting. The results indicate that the types of splint and the fixation period are generally not significant variables when related to healing outcomes. This appraisal identified difficulties in the design of animal experimentation to correctly simulate some dental injuries. Some of the studies employed rigid splinting techniques, which are not representative of current recommendations. Recommended splinting treatment protocols for teeth that have been luxated, avulsed or root-fractured teeth are formulated on the strength of research evidence. Despite the ranking of these studies in this appraisal as low levels of evidence, these recommendations should be considered ,best practice', a core philosophy of evidence-based dentistry. [source] Correlated attributes and categorization in the first half-year of lifeDEVELOPMENTAL PSYCHOBIOLOGY, Issue 2 2004Ramesh S. Bhatt Abstract In two experiments with 36 human infants, we asked whether 3- and 6-month-olds could use correlations between attributes of individual objects to categorize. Infants learned to kick to move block mobiles that simultaneously displayed two categories defined by the figures displayed on them: the colors of the figures and the colors of the blocks. Two features were correlated, and the third varied across categories. Only 6-month-olds categorized novel category exemplars that preserved the original feature correlations (Experiment 1A), but both 3- and 6-month-olds discriminated feature recombinations that broke the original correlations (Experiment 1B). When category exemplars were presented successively, 6-month-olds also learned the feature correlations and used them to categorize (Experiment 2), but their performance was less robust. Infants' superior learning when stimuli were presented simultaneously may reflect "unitization," a learning disposition unique to immature infants. These experiments reveal that infants' ability to use correlated attributes to categorize emerges months earlier than previously thought. © 2004 Wiley Periodicals, Inc. Dev Psychobiol 44: 103,115, 2004. [source] Toddlers can adaptively change how they categorize: same objects, same session, two different categorical distinctionsDEVELOPMENTAL SCIENCE, Issue 1 2009Jessica S. Horst Two experiments demonstrate that 14- to 18-month-old toddlers can adaptively change how they categorize a set of objects within a single session, and that this ability is related to vocabulary size. In both experiments, toddlers were presented with a sequential touching task with objects that could be categorized either according to some perceptually salient dimension corresponding to a taxonomic distinction (e.g. animals vs. vehicles) or to some less obvious dimension (e.g. rigid vs. deformable). In each experiment, children with larger productive vocabularies responded to both dimensions, showing evidence of sensitivity to each way of categorizing the items. Children with smaller productive vocabularies attended only to the taxonomically related categorical grouping. These experiments confirm that toddlers can adaptively shift the basis of their categorization and highlight the dynamic interaction between the child and the current task in early categorization. [source] Origins of a stereotype: categorization of facial attractiveness by 6-month-old infantsDEVELOPMENTAL SCIENCE, Issue 2 2004Jennifer L. Ramsey Like adults, young infants prefer attractive to unattractive faces (e.g. Langlois, Roggman, Casey, Ritter, Rieser-Danner & Jenkins, 1987; Slater, von der Schulenburg, Brown, Badenoch, Butterworth, Parsons & Samuels, 1998). Older children and adults stereotype based on facial attractiveness (Eagly, Ashmore, Makhijani & Longo, 1991; Langlois, Kalakanis, Rubenstein, Larson, Hallam & Smooth, 2000). How do preferences for attractive faces develop into stereotypes? Several theories of stereotyping posit that categorization of groups is necessary before positive and negative traits can become linked to the groups (e.g. Tajfel, Billig, Bundy & Flament, 1971; Zebrowitz-McArthur, 1982). We investigated whether or not 6-month-old infants can categorize faces as attractive or unattractive. In Experiment 1, we familiarized infants to unattractive female faces; in Experiment 2, we familiarized infants to attractive female faces and tested both groups of infants on novel faces from the familiar or novel attractiveness category. Results showed that 6-month-olds categorized attractive and unattractive female faces into two different groups of faces. Experiments 3 and 4 confirmed that infants could discriminate among the faces used in Experiments 1 and 2, and therefore categorized the faces based on their similarities in attractiveness rather than because they could not differentiate among the faces. These findings suggest that categorization of facial attractiveness may underlie the development of the ,beauty is good' stereotype. [source] German-learning infants' ability to detect unstressed closed-class elements in continuous speechDEVELOPMENTAL SCIENCE, Issue 2 2003Barbara Höhle The paper reports on two experiments with the head turn preference method which provide evidence that already at 7 to 9 months, but not yet at 6 months, German-learning infants do recognize unstressed closed-class lexical elements in continuous speech. These findings support the view that even preverbal children are able to compute at least phonological representations for closed-class functional elements. They also suggest that these elements must be available to the language learning mechanisms of the child from very early on, allowing the child to make use of the distributional properties of closed-class lexical elements for further top-down analysis of the linguistic input, e.g. segmentation and syntactic categorization. [source] Orbital sarcoma in HIV positive patient: A diagnostic dilemmaDIAGNOSTIC CYTOPATHOLOGY, Issue 1 2010D.N.B., Nalini Gupta M.D. Abstract Diagnosis of a high-grade sarcoma on fine needle aspiration cytology (FNAC) may not pose any difficulty; however, further sub-typing is sometimes difficult. The clinical data, investigations, and finer points on cytomorphology may help for proper categorization of the tumor, however, we encountered a case of orbital sarcoma in an Human Immunodeficiency Virus (HIV) positive patient, in which further sub-typing was difficult even on histopathology and immunohistochemistry was helpful. The diagnostic difficulties on FNA cytology smears as well as histopathology are highlighted. Diagn. Cytopathol. 2010. © 2009 Wiley-Liss, Inc. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||