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1.
J Microbiol Biol Educ ; 24(3)2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38108016

RESUMO

The Microbiology Concept Inventory is an assessment tool derived from the fundamental statements created by the American Society for Microbiology. This two-tier, multiple-choice question inventory requires students to choose the most correct answer for each question and provide a brief justification of their reasoning. Educators can utilize this tool to identify common misconceptions held by students and adjust curriculum to address and prevent the persistence of student misconceptions. Over the course of 5 years, the Microbiology Concept Inventory was annually administered to undergraduate students enrolled in entry-level, mid-level, and senior capstone microbiology courses at a mid-western rural university. Analysis was completed to compare course, year, majors and minors, gender, ethnicity, and cumulative GPA. Results of this study showed a significant difference in Microbiology Concept Inventory scores between students with high cumulative GPAs (3.5-4.0) and students with comparatively lower cumulative GPAs (2.5-2.99, 3.0-3.49). Results between the other demographic categories revealed statistically different scores in favor of white students, but no differences in scores between genders. The results suggest evidence of ethnic bias, but no gender bias as measured by the Microbiology Concept Inventory. Additionally, significant differences in scores across cohorts are indicative of improvements in the curricula due to prior targeted changes. Analysis of concept inventory results can guide curriculum changes for course instructors. Implementation of curriculum changes can enrich students' academic success.

2.
Psychol Rev ; 130(2): 368-400, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-35862077

RESUMO

Understanding the cognitive processes underlying choice requires theories that can disentangle the representation of stimuli from the processes that map these representations onto observed responses. We develop a dynamic theory of how stimuli are mapped onto discrete (choice) and onto continuous response scales. It proposes that the mapping from a stimulus to an internal representation and then to an evidence accumulation process is accomplished using multiple reference points or "anchors." Evidence is accumulated until a threshold amount for a particular response is obtained, with the relative balance of support for each anchor at that time determining the response. We tested this multiple anchored accumulation theory (MAAT) using the results of two experiments requiring discrete or continuous responses to line length and color stimuli. We manipulated the number of options for discrete responses, the number of different stimuli, and the similarity among them, and compared the outcomes to continuous response conditions. We show that MAAT accounts for several key phenomena: more accurate, faster, and more skewed distributions of responses near the ends of a response scale; lower accuracy and slower responses as the number of discrete choice options increases; and longer response times and lower accuracy when alternative responses are more similar to the target response. Our empirical and modeling results suggest that discrete and continuous response tasks can share a common evidence representation, and that the decision process is sensitive to the perceived similarity among the response options. (PsycInfo Database Record (c) 2023 APA, all rights reserved).


Assuntos
Comportamento de Escolha , Cognição , Tempo de Reação , Humanos , Tempo de Reação/fisiologia , Comportamento de Escolha/fisiologia
3.
Rev Sci Instrum ; 93(6): 063905, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35778007

RESUMO

A new shock tube facility has been designed, constructed, and characterized at the University of Central Florida. This facility is capable of withstanding pressures of up to 1000 atm, allowing for combustion diagnostics of extreme conditions, such as in rocket combustion chambers or in novel power conversion cycles. For studies with toxic gas impurities, the high initial pressures required the development of a gas delivery system to ensure the longevity of the facility and the safety of the personnel. Data acquisition and experimental propagation were implemented with remote access to ensure safety, paired with a LabVIEW- and Python-based user interface. Thus far, test pressures of 270 atm, blast pressures of 730 atm, and temperatures approaching 10 000 K have been achieved. The extreme limitations of this facility allow for emission spectroscopy to be performed during the oxidation of fuel mixtures, e.g., alkanes diluted in argon and carbon dioxide. Ignition delay times were determined and compared to simulations using chemical kinetic mechanisms. The design, experimental procedures, processes of analysis, and uncertainty determination are outlined, and typical pressure profiles are compared with a new gas dynamics solver and empirical correlations developed across multiple shock tube facilities. Preliminary reactive mixture analyses are included with further investigation of the mixtures outlined.

4.
J Inorg Biochem ; 226: 111636, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34717253

RESUMO

Radical S-adenosylmethionine (SAM) enzymes utilize a [4Fe-4S]1+ cluster and S-(5'-adenosyl)-L-methionine, (SAM), to generate a highly reactive radical and catalyze what is arguably the most diverse set of chemical reactions for any known enzyme family. At the heart of radical SAM catalysis is a highly reactive 5'-deoxyadenosyl radical intermediate (5'-dAdo●) generated through reductive cleavage of SAM or nucleophilic attack of the unique iron of the [4Fe-4S]+ cluster on the 5' C atom of SAM. Spectroscopic studies reveal the 5'-dAdo● is transiently captured in an FeC bond (Ω species). In the presence of substrate, homolytic scission of this metal­carbon bond regenerates the 5'-dAdo● for catalytic hydrogen atom abstraction. While reminiscent of the adenosylcobalamin mechanism, radical SAM enzymes appear to encompass greater catalytic diversity. In this review we discuss recent developments for radical SAM enzymes involved in unique chemical rearrangements, specifically regarding class C radical SAM methyltransferases. Illuminating this class of radical SAM enzymes is especially significant as many enzymes have been shown to play critical roles in pathogenesis and the synthesis of novel antimicrobial compounds.


Assuntos
Proteínas Ferro-Enxofre/química , Metiltransferases/química , S-Adenosilmetionina/química , Catálise
5.
Am J Obstet Gynecol MFM ; 3(6): 100459, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34403822

RESUMO

Mental health disorders are common and have a significantly negative impact on the health and well-being of women. For example, perinatal mental health disorders such as anxiety and depression are widely understood to be the most common complications of pregnancy and childbirth. Untreated mental health disorders are associated with significant obstetrical and psychiatric sequelae and have a long-lasting impact on neonatal and childhood outcomes. As front-line providers for women during times of elevated risk of psychiatric morbidity, such as pregnancy and postpartum, obstetricians and gynecologists are compelled to have familiarity with such disorders. Yet, a wide gap exists between the level of education in mental health disorders that obstetrician and gynecologist providers receive and the clinical need thereof. The objectives of this commentary are to describe the urgent need for mental health education for obstetricians and gynecologists providers and to introduce our vision for a concise, evidence-based and accessible set of digital educational materials designed to convey core concepts in women's reproductive mental health.


Assuntos
Ginecologia , Obstetrícia , Ansiedade , Transtornos de Ansiedade , Criança , Feminino , Educação em Saúde , Humanos , Recém-Nascido , Gravidez
6.
Br J Dermatol ; 185(2): 353-362, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33782946

RESUMO

BACKGROUND: Melanoma incidence has been dramatically increasing worldwide. Psoralen, a known photocarcinogen, is naturally abundant in citrus products, leading to the hypothesis that high citrus consumption may increase melanoma risk. OBJECTIVES: To investigate the association between total citrus consumption and melanoma risk, and the association between individual citrus products and melanoma risk, and to test for interactions between total citrus intake and established melanoma risk factors. METHODS: Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between citrus consumption and melanoma risk among 1592 cases and 197 372 controls from the UK Biobank cohort. Citrus consumption data were collected via five rounds of 24-h recall questionnaires. International Classification of Diseases codes were used to determine melanoma outcome. RESULTS: After adjusting for potential confounders, participants in the highest category of total citrus intake (> 2 servings per day) had a significantly increased risk of melanoma (OR 1·63, 95% CI 1·24-2·12) relative to those with no consumption. For individual citrus products, participants with the most orange and orange juice consumption (> 1 serving per day) had a significantly increased melanoma risk relative to those with no consumption (OR 1·79, 95% CI 1·07-2·78 and OR 1·54, 95% CI 1·10-2·10, respectively). Fair- or very fair-skinned participants with high citrus consumption had an even greater melanoma risk (OR 1·75, 95% CI 1·31-2·29). CONCLUSIONS: High citrus consumption was associated with an increased risk of melanoma in a large, prospective, population-based cohort. Further validation of these findings could lead to improved melanoma prevention strategies.


Assuntos
Citrus , Melanoma , Bancos de Espécimes Biológicos , Dieta , Humanos , Melanoma/epidemiologia , Melanoma/etiologia , Estudos Prospectivos , Fatores de Risco , Reino Unido/epidemiologia
7.
Psychol Rev ; 127(2): 186-215, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31580104

RESUMO

Independent racing evidence-accumulator models have proven fruitful in advancing understanding of rapid decisions, mainly in the case of binary choice, where they can be relatively easily estimated and are known to account for a range of benchmark phenomena. Typically, such models assume a one-to-one mapping between accumulators and responses. We explore an alternative independent-race framework where more than one accumulator can be associated with each response, and where a response is triggered when a sufficient number of accumulators associated with that response reach their thresholds. Each accumulator is primarily driven by the difference in evidence supporting one versus another response (i.e., that response's "advantage"), with secondary inputs corresponding to the total evidence for both responses and a constant term. We use Brown and Heathcote's (2008) linear ballistic accumulator (LBA) to instantiate the framework in a mathematically tractable measurement model (i.e., a model whose parameters can be successfully recovered from data). We show this "advantage LBA" model provides a detailed quantitative account of a variety of benchmark binary and multiple choice phenomena that traditional independent accumulator models struggle with; in binary choice the effects of additive versus multiplicative changes to input values, and in multiple choice the effects of manipulations of the strength of lure (i.e., nontarget) stimuli and Hick's law. We conclude that the advantage LBA provides a tractable new avenue for understanding the dynamics of decisions among multiple choices. (PsycINFO Database Record (c) 2020 APA, all rights reserved).


Assuntos
Comportamento de Escolha , Modelos Teóricos , Inibição Neural , Tempo de Reação , Humanos
9.
Anim Cogn ; 19(1): 75-89, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26286201

RESUMO

Perceiving and comparing ratios are crucial skills for humans. Little is known about whether other animals can compare ratios. We trained two rhesus macaques (Macaca mulatta) to choose arrays that contained the greater ratio of positive to negative stimuli, regardless of the absolute number of stimuli in each of the two choice arrays. Subjects learned this task, and their performance generalized to novel ratios. Moreover, performance was modulated by the ratio between ratios; subjects responded more quickly and accurately when the ratio between ratios was higher. Control conditions ruled out the possibility that subjects were relying on surface area, although the ratio between ratios of surface area did seem to influence their choices. Our results demonstrate that rhesus monkeys can compare discrete ratios, demonstrating not only proportional reasoning ability but also the ability to reason about relations between relations.


Assuntos
Comportamento de Escolha , Discriminação Psicológica , Macaca mulatta/psicologia , Animais , Cognição , Condicionamento Operante , Feminino , Conceitos Matemáticos
10.
CPT Pharmacometrics Syst Pharmacol ; 3: e118, 2014 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-24918743

RESUMO

Recent clinical studies suggest sustained treatment effects of interleukin-1ß (IL-1ß)-blocking therapies in type 2 diabetes mellitus. The underlying mechanisms of these effects, however, remain underexplored. Using a quantitative systems pharmacology modeling approach, we combined ex vivo data of IL-1ß effects on ß-cell function and turnover with a disease progression model of the long-term interactions between insulin, glucose, and ß-cell mass in type 2 diabetes mellitus. We then simulated treatment effects of the IL-1 receptor antagonist anakinra. The result was a substantial and partly sustained symptomatic improvement in ß-cell function, and hence also in HbA1C, fasting plasma glucose, and proinsulin-insulin ratio, and a small increase in ß-cell mass. We propose that improved ß-cell function, rather than mass, is likely to explain the main IL-1ß-blocking effects seen in current clinical data, but that improved ß-cell mass might result in disease-modifying effects not clearly distinguishable until >1 year after treatment.

11.
Cogn Sci ; 38(4): 701-35, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24124986

RESUMO

Discrete choice experiments--selecting the best and/or worst from a set of options--are increasingly used to provide more efficient and valid measurement of attitudes or preferences than conventional methods such as Likert scales. Discrete choice data have traditionally been analyzed with random utility models that have good measurement properties but provide limited insight into cognitive processes. We extend a well-established cognitive model, which has successfully explained both choices and response times for simple decision tasks, to complex, multi-attribute discrete choice data. The fits, and parameters, of the extended model for two sets of choice data (involving patient preferences for dermatology appointments, and consumer attitudes toward mobile phones) agree with those of standard choice models. The extended model also accounts for choice and response time data in a perceptual judgment task designed in a manner analogous to best-worst discrete choice experiments. We conclude that several research fields might benefit from discrete choice experiments, and that the particular accumulator-based models of decision making used in response time research can also provide process-level instantiations for random utility models.


Assuntos
Atitude , Comportamento de Escolha , Cognição , Modelos Psicológicos , Humanos , Julgamento , Tempo de Reação
12.
Clin Auton Res ; 22(1): 25-33, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21792728

RESUMO

OBJECTIVE: Cognitive deficits are reported in 10-60% of individuals with SCI, the primary etiology of these deficits is believed to be concomitant traumatic brain injury (TBI). We recently documented diminished memory and marginally deficient attention and processing speed in individuals with SCI discordant for hypotension but matched for TBI. METHODS: Twenty-nine individuals participated: 16 non-SCI controls, 6 paraplegic (T2-T10) and 7 tetraplegic (C4-C8). The Stroop test was used to measure cognitive function and transcranial Doppler ultrasound was used to measure cerebral blood flow (CBF) while resting (5 min) and continuously during cognitive testing. Mean arterial pressure (MAP) was calculated from three brachial blood pressures and cerebral vascular resistance index was calculated as: CVRi = MAP/CBF. RESULTS: The paraplegia group (54 ± 6) was marginally older than the non-SCI (42 ± 15; p = 0.06) and tetraplegic (42 ± 11; p = 0.09) groups. Compared to non-SCI group, normalized t-score on the Stroop Color (SC) task was significantly lower in the paraplegic group (p < 0.05). In the tetraplegic group, MAP was significantly lower (p < 0.05) than the non-SCI and paraplegic groups, and related to SC t-score (r (2) = 0.873; p < 0.01). In the paraplegic group, CBF was reduced (p < 0.05) and CVRi increased (p < 0.05) compared to the non-SCI group, and CVRi was increased compared to the tetraplegic group (p < 0.05). A significant inverse relationship was noted between change in CVRi and SC t-score in the non-SCI group. CONCLUSION: Asymptomatic hypotension relates to cognitive performance in persons with tetraplegia; therefore, BP normalization should be considered. The inappropriate cerebral vascular response to cognitive testing and poor test performance should be investigated in persons with paraplegia.


Assuntos
Circulação Cerebrovascular/fisiologia , Cognição/fisiologia , Hemodinâmica/fisiologia , Testes Neuropsicológicos , Traumatismos da Medula Espinal/fisiopatologia , Traumatismos da Medula Espinal/psicologia , Adulto , Idoso , Pressão Sanguínea/fisiologia , Interpretação Estatística de Dados , Feminino , Humanos , Masculino , Processos Mentais/fisiologia , Pessoa de Meia-Idade , Paraplegia/fisiopatologia , Paraplegia/psicologia , Quadriplegia/fisiopatologia , Quadriplegia/psicologia , Estresse Psicológico/fisiopatologia , Teste de Stroop , Ultrassonografia Doppler Transcraniana , Adulto Jovem
13.
J Biomed Nanotechnol ; 7(3): 406-14, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21830481

RESUMO

Curcumin is a polyphenol obtained from the plant Curcuma longa (called turmeric) that displays several pharmacological activities, including anti-inflammatory, antioxidant, antimicrobial and antitumoral activity, but clinical use has been limited by its poor solubility in water and, consequently, minimal systemic bioavailability. We have therefore formulated the drug into nanocarrier systems in an attempt to improve its therapeutic properties. This study evaluates the effect of intraperitoneally administered nanocapsules containing curcumin on subcutaneous melanoma in mice inoculated with B16-F10 cells, and on the cytotoxicity activity against B16-F10 cells in vitro. Phagocytic uptake of formulations was also evaluated upon incubation with macrophage J774 cells by fluorescence microscopy. Lipid and polymeric nanocapsules were prepared by the phase inversion and nanoprecipitation methods, respectively. The uptake of the lipid nanocapsules prepared using Solutol HS15 was significantly reduced in J774 cells. Curcumin, as free drug or as drug-loaded nanocapsules, was administrated at a dose of 6 mg/kg twice a week for 21 days. Free drug and curcumin-loaded nanocapsules significantly reduced tumor volume (P < 0.05 vs. control), but no difference was found in the antitumor activity displayed by lipid and polymeric nanocapsules. This assumption was supported by the in vitro study, in which free curcumin as well as loaded into nanocapsules caused significant reduction of cell viability in a concentration- and time-dependent manner.


Assuntos
Curcumina/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Nanocápsulas , Tensoativos , Animais , Transporte Biológico/efeitos dos fármacos , Linhagem Celular Tumoral , Curcumina/farmacocinética , Curcumina/uso terapêutico , Estabilidade de Medicamentos , Íons , Lipossomos , Macrófagos/imunologia , Melanoma Experimental/tratamento farmacológico , Camundongos , Camundongos Endogâmicos C57BL , Nanocápsulas/química , Tamanho da Partícula , Tensoativos/química
14.
Atten Percept Psychophys ; 73(6): 1977-86, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21671155

RESUMO

The bow effect is ubiquitous in standard absolute identification experiments; stimuli at the center of the stimulus-set range elicit slower and less accurate responses than do others. This effect has motivated various theoretical accounts of performance, often involving the idea that end-of-range stimuli have privileged roles. Two other phenomena (practice effects and improved performance for frequently-presented stimuli) have an important but less explored consequence for the bow effect: Standard within-subjects manipulations of set size could disrupt the bow effect. We found this disruption for stimulus types that support practice effects (line length and tone frequency), suggesting that the bow effect is more fragile than has been thought. Our results also have implications for theoretical accounts of absolute identification, which currently do not include mechanisms for practice effects, and provide results consistent with those in the literature on stimulus-specific learning.


Assuntos
Atenção , Percepção Sonora , Percepção da Altura Sonora , Tempo de Reação , Percepção de Tamanho , Habituação Psicofisiológica , Humanos , Prática Psicológica
15.
Diabetologia ; 53(5): 924-36, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20221584

RESUMO

AIMS/HYPOTHESIS: AMP-activated protein kinase (AMPK) is an evolutionarily conserved enzyme and a target of glucose-lowering agents, including metformin. However, the precise role or roles of the enzyme in controlling insulin secretion remain uncertain. METHODS: The catalytic alpha1 and alpha2 subunits of AMPK were ablated selectively in mouse pancreatic beta cells and hypothalamic neurons by breeding Ampkalpha1 [also known as Prkaa1]-knockout mice, bearing floxed Ampkalpha2 [also known as Prkaa2] alleles (Ampkalpha1 ( -/- ),alpha2( fl/fl ),), with mice expressing Cre recombinase under the rat insulin promoter (RIP2). RIP2 was used to express constitutively activated AMPK selectively in beta cells in transgenic mice. Food intake, body weight and urinary catecholamines were measured using metabolic cages. Glucose and insulin tolerance were determined after intraperitoneal injection. Beta cell mass and morphology were analysed by optical projection tomography and confocal immunofluorescence microscopy, respectively. Granule docking, insulin secretion, membrane potential and intracellular free Ca(2+) were measured with standard techniques. RESULTS: Trigenic Ampkalpha1 ( -/- ),alpha2( fl/fl ) expressing Cre recombinase and lacking both AMPKalpha subunits in the beta cell, displayed normal body weight and increased insulin sensitivity, but were profoundly insulin-deficient. Secreted catecholamine levels were unchanged. Total beta cell mass was unaltered, while mean islet and beta cell volume were reduced. AMPK-deficient beta cells displayed normal glucose-induced changes in membrane potential and intracellular free Ca(2+), while granule docking and insulin secretion were enhanced. Conversely, betaAMPK transgenic mice were glucose-intolerant and displayed defective insulin secretion. CONCLUSIONS/INTERPRETATION: Inhibition of AMPK activity within the beta cell is necessary, but not sufficient for stimulation of insulin secretion by glucose to occur. AMPK activation in extrapancreatic RIP2.Cre-expressing cells might also influence insulin secretion in vivo.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Hipotálamo/metabolismo , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Neurônios/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Análise de Variância , Animais , Glicemia/metabolismo , Peso Corporal/genética , Gorduras na Dieta , Ingestão de Alimentos/genética , Eletrofisiologia , Imunofluorescência , Teste de Tolerância a Glucose , Hiperglicemia/genética , Hiperglicemia/metabolismo , Insulina/genética , Secreção de Insulina , Camundongos , Camundongos Knockout , Regiões Promotoras Genéticas/genética , Ratos
16.
Psychon Bull Rev ; 16(3): 583-93, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19451389

RESUMO

Unidimensional absolute identification-identifying a presented stimulus from an ordered set-is a common component of everyday tasks. Laboratory investigations have mostly used equally spaced stimuli, and the theoretical debate has focused on the merits of purely relative versus purely absolute models. Absolute models incorporate substantial knowledge of the complete set of stimuli, whereas relative models allow only partial knowledge and assume that each stimulus is compared with recently observed stimuli. We test and refute a general prediction made by relative models, that accuracy is very low for some stimulus sequences when the stimuli are unequally spaced. We conclude that, although relative judgment processes may occur in absolute identification, a model must incorporate long-term referents to explain performance with unequally spaced stimuli. This implies that purely relative models cannot provide a general account of absolute identification.


Assuntos
Atenção , Julgamento , Percepção Sonora , Rememoração Mental , Modelos Psicológicos , Percepção da Altura Sonora , Aprendizagem Seriada , Enquadramento Psicológico , Humanos , Desempenho Psicomotor , Tempo de Reação
17.
Palliat Med ; 23(2): 126-31, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18974174

RESUMO

This article describes health and social care professionals' perceptions of palliative care and facilitators and barriers to the delivery of such care for patients with advanced chronic obstructive pulmonary disease. Health professionals participated in semi structured interviews and focus groups which were analysed using content analysis. According to participants, care of patients with chronic obstructive pulmonary disease is focused upon the management of symptoms, with emphasis focused predominately on an acute model of care. Key barriers towards the delivery of palliative care included the reluctance to negotiatie end-of-life decisions and a perceived lack of understanding among patients and carers regarding the illness trajectory. Consequently the delivery of palliative care was viewed as a specialist role rather than an integral component of care. There is a need for education and training for health and social care professions to plan and provide high quality end-of-life care.


Assuntos
Atitude do Pessoal de Saúde , Cuidadores , Necessidades e Demandas de Serviços de Saúde/normas , Cuidados Paliativos/normas , Doença Pulmonar Obstrutiva Crônica/terapia , Qualidade de Vida , Adulto , Idoso , Feminino , Grupos Focais , Necessidades e Demandas de Serviços de Saúde/organização & administração , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação das Necessidades/organização & administração , Avaliação das Necessidades/normas , Cuidados Paliativos/organização & administração , Pesquisa Qualitativa
18.
Psychol Res ; 73(3): 308-16, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-18704493

RESUMO

Identification accuracy for sets of perceptually discriminable stimuli ordered on a single dimension (e.g., line length) is remarkably low, indicating a fundamental limit on information processing capacity. This surprising limit has naturally led to a focus on measuring and modeling choice probability in absolute identification research. We show that choice response time (RT) results can enrich our understanding of absolute identification by investigating dissociation between RT and accuracy as a function of stimulus spacing. The dissociation is predicted by the SAMBA model of absolute identification (Brown, Marley, Dockin, & Heathcote, 2008), but cannot easily be accommodated by other theories. We show that SAMBA provides an accurate, parameter free, account of the dissociation that emerges from the architecture of the model and the physical attributes of the stimuli, rather than through numerical adjustment. This violation of the pervasive monotonic relationship between RT and accuracy has implications for model development, which are discussed.


Assuntos
Discriminação Psicológica , Tempo de Reação , Atenção , Comportamento de Escolha/fisiologia , Humanos , Modelos Psicológicos , Estimulação Física/métodos
19.
Artigo em Português | LILACS | ID: lil-540394

RESUMO

As síndromes mielodisplásicas (SMDs) são caracterizadas por uma desordem clonal de células primordiais (stem cell) e hematopoese ineficaz que levam à displasia de uma ou mais linhagens celulares da medula óssea, citopenias periféricas e instabilidade genética, as quais aumentam o risco de transformação à leucemia mieloide aguda. Esse grupo heterogêneo de doenças hematopoéticas pode surgir como doença primária, que possui etiologia variada e não completamente definida, ou secundária ao tratamento quimioterápico ou radioterápico para outras neoplasias. O surgimento e aprimoramento de tecnologias de diagnóstico geraram uma melhor compreensão dos processos envolvidos na gênese e evolução das SMDs, o que possibilitou o desenvolvimento de marcadores de diagnóstico e acompanhamentos cada vez mais precoces e específicos. No ano de 2008, a Organização Mundial da Saúde (OMS) redefiniu os critérios para classificação das SMDs, dividindo-as em sete subgrupos. Nessa classificação foram incluídos novos aspectos imunofenotípicos, genéticos, citomorfológicos e moleculares, o que tornou o domínio e o acesso a tecnologias de ponta imprescindíveis para a realização do diagnóstico das SMDs. Apesar dos avanços tecnológicos, alguns pontos, como as bases moleculares da transformação de SMD para LMA, ainda não estão bem esclarecidos, fazendo necessária a continuação de estudos nessa área. Diante disso, essa revisão busca compilar dados atuais dos aspectos moleculares e laboratoriais das SMDs.


Myelodysplastic syndromes (MDSs) are characterized by a stem cell clonal disorder and ineffective hematopoiesis which causes dysplasia in one or more bone marrow hematopoietic cell lineages, peripheral cytopenia and genetic instability with enhanced risk to transform into acute myeloid leukemia (AML). This heterogeneous group of hematopoietic diseases can develop as primary diseases, which posses a variable and not completely defined etiology, or as secondary to chemotherapy or radiotherapy for other neoplasias. The evolution of diagnostic tests has improved comprehension of the process involved in the genesis and evolution of MDSs, making the development of earlier and more specific tests for diagnosis and follow ups possible. In 2008, the World Health Organization (WHO) redefined the criteria for the classification of MDSs, dividing them into seven subgroups. This classification included new immunophenotypic, genetic, cytomorphologic and molecular features, which are essential for the diagnosis of MDSs and for a better comprehension of the disease. Despite technological advances, some details, such as the molecular basis of the transformation of MDS to AML, are still not completely understood, which makes further studies in this field necessary. Hence, the objective of this review is to make a compilation of recent molecular and laboratory aspects of MDS.


Assuntos
Humanos , Imunofenotipagem , Síndromes Mielodisplásicas , Síndromes Mielodisplásicas/classificação , Organização Mundial da Saúde
20.
Percept Psychophys ; 70(7): 1274-88, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18927009

RESUMO

Researchers studying absolute identification have long known that it takes more time to identify a stimulus in the middle of a range than one at the extremes. That is, there is an inverted-U relation between mean response time and response position. In this task, an inverted-U relation also exists between response uncertainty and response position. Similarly, an inverted-U relation between mean response time and response position has been found for psychometric measures involving questions about the self. However, psychophysicists explain these inverted-U effects differently than do self-schema researchers. We propose an integrative framework in which task constraints explain these effects. To verify the generality of these inverted-U effects, we hypothesized that they would exist in three tasks having similar constraints--in this case, tasks involving the judgment of subjective properties of faces on a Likert-type scale. Our results are consistent with this hypothesis. We discuss the relevance of the results for other applications of Likert-type scales.


Assuntos
Face , Julgamento , Percepção Visual , Feminino , Humanos , Masculino , Modelos Teóricos , Tempo de Reação , Adulto Jovem
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