Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 28
Filtrar
1.
Am J Occup Ther ; 77(4)2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37540763

RESUMO

IMPORTANCE: Outcomes research on the impact of seating and mobility services delivered using a short-term medical mission (STMM) model is limited. OBJECTIVE: To evaluate the impact of seating and mobility services on the occupational performance of individuals with disabilities in El Salvador. DESIGN: One-group retrospective pretest-posttest. SETTING: Clinical (El Salvador). PARTICIPANTS: Individuals with disabilities in El Salvador. OUTCOMES AND MEASURES: Survey and the standardized Wheelchair Outcome Measure (WhOM) for those who received a wheelchair as their mobility device. METHOD: Participants rated satisfaction with performance of preferred in-home and out-of-home occupations on the WhOM before and after receiving seating and mobility services. RESULTS: For most survey questions assessing the impact on activities of daily living, more than 86% of the respondents selected agree or strongly agree. Nearly half of the respondents reported that questions regarding work and education were not applicable. Participants' WhOM scores (n = 86) demonstrated a statistically significant improvement in performance satisfaction for both in-home (p < .001; d > 1) and out-of-home (p < .001; d > 1) occupations after they received services, with a huge effect size (d > 2). CONCLUSIONS AND RELEVANCE: The findings suggest that seating and mobility services provided by rehabilitation professionals in El Salvador improved occupational performance for people with disabilities. Compared with STMMs that solely provide equipment, the findings emphasize the importance of professional service provision with education and training as best practice. What This Article Adds: Seating and mobility services delivered through a STMM model may improve occupational performance for individuals with disabilities. However, STMMs should be carefully planned in collaboration with in-country partners, provide customized seating systems, and include education and training from licensed rehabilitation professionals.


Assuntos
Pessoas com Deficiência , Tecnologia Assistiva , Cadeiras de Rodas , Humanos , Atividades Cotidianas , El Salvador , Estudos Retrospectivos , Pessoas com Deficiência/reabilitação
2.
Arch Sex Behav ; 49(5): 1631-1643, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32222850

RESUMO

Historically, people with minority sexual and gender identities (e.g., gay, lesbian, bisexual, transgender) have been pathologized by mental and medical health practitioners. The potential for pathologization of asexuality is particularly salient considering a lack of sexual desire or interest has been studied in relationship to depression, antidepressant medication, and hypothyroidism. To explore this potential pathologization, asexual individuals were asked about their interactions with mental health and medical practitioners. The study included 136 adult participants, primarily from the U.S., who self-identified as asexual. Participants completed an online survey which contained questions about their experiences with mental health and medical practitioners. Results indicated that the majority of participants did not disclose their identity and felt uncomfortable discussing issues related to sexuality with their providers. Participants were more likely to disclose their asexual identity to mental health providers, as compared to medical providers. Participants who had positive experiences were more likely than those who had negative experiences to indicate that their practitioners were familiar with asexuality, accepted the participant's identity completely, and reacted to the disclosure in a positive and affirming manner. Positive experiences included practitioners educating themselves about asexuality, while negative experiences included practitioners disbelieving the existence of asexuality, and between one quarter and one half of participants reported that practitioners attributed their asexuality to a health condition. The findings from this study demonstrate the importance of including information about asexual identities in health education and ongoing diversity training in order to increase the cultural sensitivity of health practitioners.


Assuntos
Identidade de Gênero , Pessoal de Saúde/psicologia , Adulto , Feminino , Humanos , Estudos Longitudinais , Masculino , Adulto Jovem
3.
Arch Phys Med Rehabil ; 98(9): 1821-1827, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28130084

RESUMO

OBJECTIVE: To determine the immediate effect of a portable, myoelectric elbow-wrist-hand orthosis on paretic upper extremity (UE) impairment in chronic, stable, moderately impaired stroke survivors. DESIGN: Observational cohort study. SETTING: Outpatient rehabilitation clinic. PARTICIPANTS: Participants exhibiting chronic, moderate, stable, poststroke, UE hemiparesis (N=18). INTERVENTIONS: Subjects were administered a battery of measures testing UE impairment and function. They then donned a fabricated myoelectric elbow-wrist-hand orthosis and were again tested on the same battery of measures while wearing the device. MAIN OUTCOME MEASURES: The primary outcome measure was the UE Section of the Fugl-Meyer Scale. Subjects were also administered a battery of functional tasks and the Box and Block (BB) test. RESULTS: Subjects exhibited significantly reduced UE impairment while wearing the myoelectric elbow-wrist-hand orthosis (FM: t17=8.56, P<.0001) and increased quality in performing all functional tasks while wearing the myoelectric elbow-wrist-hand orthosis, with 3 subtasks showing significant increases (feeding [grasp]: z=2.251, P=.024; feeding [elbow]: z=2.966, P=.003; drinking [grasp]: z=3.187, P=.001). Additionally, subjects showed significant decreases in time taken to grasp a cup (z=1.286, P=.016) and increased gross manual dexterity while wearing a myoelectric elbow-wrist-hand orthosis (BB test: z=3.42, P<.001). CONCLUSIONS: Results suggest that UE impairment, as measured by the Fugl-Meyer Scale, is significantly reduced when donning a myoelectric elbow-wrist-hand orthosis, and these changes exceeded the Fugl-Meyer Scale's clinically important difference threshold. Further, utilization of a myoelectric elbow-wrist-hand orthosis significantly increased gross manual dexterity and performance of certain functional tasks. Future work will integrate education sessions to increase subjects' ability to perform multijoint functional movements and attain consistent functional changes.


Assuntos
Terapia por Estimulação Elétrica/instrumentação , Aparelhos Ortopédicos , Paresia/reabilitação , Reabilitação do Acidente Vascular Cerebral/instrumentação , Acidente Vascular Cerebral/fisiopatologia , Idoso , Doença Crônica , Estudos de Coortes , Avaliação da Deficiência , Cotovelo/fisiopatologia , Terapia por Estimulação Elétrica/métodos , Feminino , Mãos/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Paresia/etiologia , Paresia/fisiopatologia , Recuperação de Função Fisiológica , Acidente Vascular Cerebral/complicações , Reabilitação do Acidente Vascular Cerebral/métodos , Resultado do Tratamento , Extremidade Superior/fisiopatologia , Punho/fisiopatologia
4.
Neural Plast ; 2017: 6971206, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28243474

RESUMO

Objectives. (a) To determine associations among motor evoked potential (MEP) amplitude, MEP latency, lower extremity (LE) impairment, and gait velocity and (b) determine the association between the presence of a detectable MEP signal with LE impairment and with gait velocity. Method. 35 subjects with chronic, stable LE hemiparesis were undergone TMS, the LE section of the Fugl-Meyer Impairment Scale (LE FM), and 10-meter walk test. We recorded presence, amplitude, and latency of MEPs in the affected tibialis anterior (TA) and soleus (SO). Results. MEP presence was associated with higher LEFM scores in both the TA and SO. MEP latency was larger in subjects with lower LEFM and difficulty walking. Conclusion. MEP latency appears to be an indicator of LE impairment and gait. Significance. Our results support the precept of using TMS, particularly MEP latency, as an adjunctive LE outcome measurement and prognostic technique.


Assuntos
Potencial Evocado Motor , Transtornos Neurológicos da Marcha/diagnóstico , Transtornos Neurológicos da Marcha/fisiopatologia , Neuronavegação/métodos , Paresia/diagnóstico , Paresia/fisiopatologia , Acidente Vascular Cerebral/complicações , Estimulação Magnética Transcraniana/métodos , Idoso , Feminino , Marcha , Transtornos Neurológicos da Marcha/etiologia , Humanos , Extremidade Inferior/fisiopatologia , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/fisiopatologia , Paresia/etiologia , Índice de Gravidade de Doença
5.
Am J Occup Ther ; 71(3): 7103190080p1-7103190080p6, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28422634

RESUMO

OBJECTIVE: To determine the impact of transcranial direct current stimulation (tDCS) combined with repetitive, task-specific training (RTP) on upper-extremity (UE) impairment in a chronic stroke survivor with moderate impairment. METHOD: The participant was a 54-yr-old woman with chronic, moderate UE hemiparesis after a single stroke that had occurred 10 yr before study enrollment. She participated in 45-min RTP sessions 3 days/wk for 8 wk. tDCS was administered concurrent to the first 20 min of each RTP session. RESULTS: Immediately after intervention, the participant demonstrated marked score increases on the UE section of the Fugl-Meyer Scale and the Motor Activity Log (on both the Amount of Use and the Quality of Movement subscales). CONCLUSION: These data support the use of tDCS combined with RTP to decrease impairment and increase UE use in chronic stroke patients with moderate impairment. This finding is crucial, given the paucity of efficacious treatment approaches in this impairment level.


Assuntos
Terapia por Exercício/métodos , Paresia/reabilitação , Reabilitação do Acidente Vascular Cerebral/métodos , Acidente Vascular Cerebral/fisiopatologia , Estimulação Transcraniana por Corrente Contínua/métodos , Extremidade Superior , Doença Crônica , Terapia Combinada , Feminino , Humanos , Pessoa de Meia-Idade , Paresia/etiologia , Paresia/fisiopatologia , Índice de Gravidade de Doença , Acidente Vascular Cerebral/complicações , Resultado do Tratamento
6.
J Stroke Cerebrovasc Dis ; 24(10): 2207-12, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26231474

RESUMO

BACKGROUND: The National Institutes of Health Stroke Scale (NIHSS) is purported to be associated with long-term outcomes. This study determined the concurrent validity of the NIHSS with the Stroke Impact Scale (SIS), a previously validated measure of health status in chronic stroke survivors. METHODS: The NIHSS and the SIS were administered to 147 subjects before participation in a multicenter, randomized, controlled trial. A Spearman's rho was used to determine correlations between NIHSS total score and (1) SIS physical dimension scores, (2) SIS overall perception of recovery scores, and (3) the SIS activities and independent activities of daily living (ADL/IADL) scores. SIS score variation and medians between subjects who scored a zero versus a nonzero on the NIHSS was also assessed. RESULTS: There was no association between total NIHSS scores and SIS physical dimension scores, SIS overall perception of recovery scores, and SIS ADL/IADL scores (P = -.036, P = .782; P = -.039, P = .640; P = -.054, P = .520; respectively). Lastly, significant variation and similar median scores on the SIS were found between those scoring a zero on the NIHSS versus those who did not score a zero. CONCLUSIONS: The NIHSS has no association with health status in chronic stroke and lacks association with measures of impairment and functional limitation. From these findings, we conclude that the NIHSS has poor validity to discern long-term poststroke outcomes and is not associated with health status. Because of possible limitation in the NIHSS's ability to accurately determine outcomes in this population, we recommend restriction of its use to the acute stage of recovery.


Assuntos
Paresia/etiologia , Índice de Gravidade de Doença , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , National Institutes of Health (U.S.)/normas , Paresia/diagnóstico , Reprodutibilidade dos Testes , Estados Unidos
8.
J Gambl Stud ; 26(4): 521-31, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20217196

RESUMO

Despite the prevalence of problem gamblers and the ethical issues involved in studying gambling behavior with humans, few animal models of gambling have been developed. When designing an animal model it is necessary to determine if behavior in the paradigm is similar to human gambling. In human studies, response latencies following winning trials and near win trials are greater than those following clear losses. Weatherly and Derenne (Anal Gambl Behav 1:79-89, 2007) investigated whether this pattern was found with rats working in an animal analogue of slot machine gambling. They found a similar pattern of response latencies but the subjects' behavior did not come under control of the visual stimuli signalling the different outcomes. The animal model of slot machine gambling we used addressed procedural issues in Weatherly and Derenne's model and examined whether reinforcer magnitude and the presence of near win trials influenced response latency and resistance to extinction. Response latencies of the six female Norway Hooded rats varied as a function of reinforcer magnitude and the presence of near-win trials. These results are consistent with prior research and with the idea that near win trials serve as conditional reinforcers.


Assuntos
Comportamento Animal , Jogo de Azar/fisiopatologia , Jogo de Azar/psicologia , Comportamento Impulsivo/fisiopatologia , Comportamento Impulsivo/psicologia , Modelos Animais , Recompensa , Experimentação Animal , Animais , Feminino , Distribuição Aleatória , Ratos , Tempo de Reação
9.
Forensic Sci Med Pathol ; 6(1): 20-34, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19924578

RESUMO

The objective of this study was to compose a reliable and readily reproducible method of predicting nasal morphology from the bony aperture, which restricts subjectivity whilst allowing anatomical nuance to be taken into account. Clinical head CT data from a sample of 79 North American subjects of varied ancestry was analysed for interrelationships between the bone and soft tissue of the nose in three dimensions, then pooled with 60 lateral cephalograms of subjects of European ancestry from England to augment nasal profile data. A series of simple regression equations was produced using linear distances between pairs of bony landmarks to predict nasal profile dimensions and restrict potential subjective error in Gerasimov's "Two-tangent" method. Maximum nasal width, the position of the alae and nostrils, and prediction of nasal asymmetry were incorporated into the resulting threedimensional nasal prediction method.


Assuntos
Nariz/anatomia & histologia , Crânio/anatomia & histologia , Adulto , Face/anatomia & histologia , Feminino , Medicina Legal , Lateralidade Funcional , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Nariz/diagnóstico por imagem , Tamanho do Órgão , Fotografação , Grupos Raciais , Análise de Regressão , Crânio/diagnóstico por imagem , Tomografia Computadorizada por Raios X
12.
Artigo em Inglês | MEDLINE | ID: mdl-31550380

RESUMO

A Native community developed the Wicozani Instrument, a 9-item self-report measure, to assess overall health and well-being from an Indigenous epistemology. The Wicozani Instrument measures mental, physical, and spiritual health and their importance to an individual's quality of life. The instrument's validity and reliability was examined through two studies. Study 1 utilized standardized measures from Native (i.e., Awareness of Connectedness Scale) and Western (i.e., Psychological Sense of School Membership and Suicide Ideation Questionnaire) epistemologies with Native and non-Native youth. Study 2 utilized a community created measure (i.e., Indigenous Healing Strategies Scale) with Dakota women. Results suggest the Wicozani Instrument is valid and reliable. The development of an Indigenous measure of overall health and well-being addresses Western atomistic frameworks, which often perpetuate the perception of Native identity as a risk factor for poor health, and works to disrupt the Cycle of Native Health Disparities.


Assuntos
Disparidades nos Níveis de Saúde , Indígenas Norte-Americanos , Saúde das Minorias , Satisfação Pessoal , Psicometria/normas , Qualidade de Vida , Autorrelato/normas , Humanos , Estados Unidos
13.
J Mot Behav ; 49(1): 8-19, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27592596

RESUMO

Stroke remains a leading cause of disability, with survivors experiencing long-term decrements in independence and quality of life. Occupational therapists (OTs) employ numerous neurorehabilitative treatment approaches to remediate impairments that are impeding performance. OTs also use physical agent modalities to facilitate increased participation and success in therapy. One such modality is transcranial direct current stimulation (tDCS), a form a noninvasive brain stimulation that can be overlaid onto task practice and delivers a constant, low intensity current into the brain. tDCS is safe, portable, and efficacious in remediating a variety of deficits, yet is not consistently incorporated into clinical practice. The authors discuss the mechanisms, safety, evidence, and potential applications of tDCS to enhance outcomes for this growing population.


Assuntos
Terapia Ocupacional/métodos , Reabilitação do Acidente Vascular Cerebral/métodos , Estimulação Transcraniana por Corrente Contínua/métodos , Animais , Humanos , Córtex Motor/fisiologia , Recuperação de Função Fisiológica , Estimulação Transcraniana por Corrente Contínua/efeitos adversos
14.
Behav Processes ; 71(2-3): 286-96, 2006 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-16413975

RESUMO

The current study examined the effects of the D2 agonist (quinpirole) and D2 antagonist (eticlopride) on temporal discrimination performance in a conditional discrimination task (Experiment I) and a delayed conditional discrimination task (Experiment II). In both experiments rats discriminated between a scheduled stimulus duration of 3 s versus 9 s. Consistent with previous reports, overall discrimination performance decreased in a dose-dependent manner with both drugs. Changes in response bias (the tendency to choose-short or choose-long irrespective of actual stimulus duration), however, were best characterized in terms of both drugs tending to attenuate the bias effects normally observed during baseline drug-free performance. Specifically, the 'choose-short' bias observed in Experiment I and at a relatively short, 0.1 s, delay in Experiment II became less extreme with increasing doses. In addition, the 'choose-long' bias observed at a relatively long, 6 s, delay in Experiment II also became less extreme with increasing doses. Thus, whether there was an apparent shift from a short response bias to long, or vice versa, was the product of the delay interval between stimulus presentation and choice rather than whether the drug in question was a D2 agonist or antagonist. Such an attenuation of bias may have arisen because of subjects confounding the delay interval with the actual discriminative stimulus duration.


Assuntos
Comportamento de Escolha/efeitos dos fármacos , Aprendizagem por Discriminação/efeitos dos fármacos , Tempo de Reação/efeitos dos fármacos , Receptores de Dopamina D2/efeitos dos fármacos , Percepção do Tempo/efeitos dos fármacos , Animais , Comportamento de Escolha/fisiologia , Condicionamento Psicológico/efeitos dos fármacos , Condicionamento Psicológico/fisiologia , Aprendizagem por Discriminação/fisiologia , Dopaminérgicos/farmacologia , Masculino , Quimpirol/farmacologia , Ratos , Tempo de Reação/fisiologia , Receptores de Dopamina D2/metabolismo , Salicilamidas/farmacologia , Estatísticas não Paramétricas , Percepção do Tempo/fisiologia
15.
Front Hum Neurosci ; 10: 394, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27555811

RESUMO

Stroke remains a leading cause of disability worldwide, with a majority of survivors experiencing long term decrements in motor function that severely undermine quality of life. While many treatment approaches and adjunctive strategies exist to remediate motor impairment, many are only efficacious or feasible for survivors with active hand and wrist function, a population who constitute only a minority of stroke survivors. Transcranial direct current stimulation (tDCS), a type of non-invasive brain stimulation, has been increasingly utilized to increase motor function following stroke as it is able to be used with stroke survivors of varying impairment levels, is portable, is relatively inexpensive and has few side effects and contraindications. Accordingly, in recent years the number of studies investigating its efficacy when utilized as an adjunct to motor rehabilitation regimens has drastically increased. While many of these trials have reported positive and promising efficacy, methodologies vary greatly between studies, including differences in stimulation parameters, outcome measures and the nature of physical practice. As such, an urgent need remains, centering on the need to investigate these methodological differences and synthesize the most current evidence surrounding the application of tDCS for post-stroke motor rehabilitation. Accordingly, the purpose of this paper is to provide a detailed overview of the most recent tDCS literature (published 2014-2015), while highlighting these variations in methodological approach, as well to elucidate the mechanisms associated with tDCS and post-stroke motor re-learning and neuroplasticity.

16.
Genetics ; 167(1): 217-31, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15166149

RESUMO

In a screen for new DNA repair mutants, we tested 6275 Drosophila strains bearing homozygous mutagenized autosomes (obtained from C. Zuker) for hypersensitivity to methyl methanesulfonate (MMS) and nitrogen mustard (HN2). Testing of 2585 second-chromosome lines resulted in the recovery of 18 mutants, 8 of which were alleles of known genes. The remaining 10 second-chromosome mutants were solely sensitive to MMS and define 8 new mutagen-sensitive genes (mus212-mus219). Testing of 3690 third chromosomes led to the identification of 60 third-chromosome mutants, 44 of which were alleles of known genes. The remaining 16 mutants define 14 new mutagen-sensitive genes (mus314-mus327). We have initiated efforts to identify these genes at the molecular level and report here the first two identified. The HN2-sensitive mus322 mutant defines the Drosophila ortholog of the yeast snm1 gene, and the MMS- and HN2-sensitive mus301 mutant defines the Drosophila ortholog of the human HEL308 gene. We have also identified a second-chromosome mutant, mus215(ZIII-2059), that uniformly reduces the frequency of meiotic recombination to <3% of that observed in wild type and thus defines a function required for both DNA repair and meiotic recombination. At least one allele of each new gene identified in this study is available at the Bloomington Stock Center.


Assuntos
Drosophila melanogaster/genética , Técnicas Genéticas , Mutagênicos , Alelos , Sequência de Aminoácidos , Animais , Sequência de Bases , Mapeamento Cromossômico , DNA/metabolismo , Reparo do DNA , Teste de Complementação Genética , Mecloretamina , Meiose , Metanossulfonato de Metila , Dados de Sequência Molecular , Mutação , Não Disjunção Genética , Recombinação Genética , Saccharomyces cerevisiae/genética , Homologia de Sequência de Aminoácidos
17.
Can Nurse ; 101(1): 20-4, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15776714

RESUMO

A street nurse position in the rural and small-town interior of British Columbia has been addressing the needs of street-involved or otherwise marginalized client populations by bringing healthcare services to wherever those clients are, rather than waiting for the clients to seek care. The primary reason for a street outreach approach is that marginalized populations face a variety of barriers to accessing traditional healthcare services--barriers such as homelessness, mental health problems, criminal involvement, lack of transportation, lack of ability to pay for prescriptions, lack of specialized or knowledgeable providers and provider discrimination. In the rural street nurse program, the target population includes the usual street nurse populations of illegal drug users and sex trade workers, which are more hidden in small communities than in larger urban centres, creating the community denial that is a barrier to healthcare access. Yet another barrier is the co-locaton of services common in small communities, where public health clinics might share a building with police services, making marginalized clients reluctant to attend clinics. The rural street nurse collaborates with public health nurses and other care providers (mental health workers, social workers, etc) with collegial advice and support, making and receiving referrals, and generally assisting one another--the street nurse through his rapport with the marginalized individuals and the others with their specialized knowledge. Rural street services are delivered whereverthe clientsfeel comfortable: a school, a drop-in centre, a mall, a youth centre or simplythe street. Services provided include sexually transmitted infection testing, chlamydia treatments, pregnancy testing emergency contraception pills and assistance with filling out forms for financial support. Accordingly, the street nurse's truck is equipped as a mobile treatment centre and office, with a cellphone and a stock of testing and treatment supplies.


Assuntos
Serviços de Saúde Comunitária/organização & administração , Serviços de Saúde Rural/organização & administração , População Rural , Especialidades de Enfermagem , Canadá , Acessibilidade aos Serviços de Saúde/organização & administração , Humanos
18.
Phys Med Rehabil Clin N Am ; 26(4): 715-27, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26522908

RESUMO

Stroke remains a leading cause of death, with most survivors experiencing long-term deficits in motor function. Upper extremity (UE) hemiparesis constitutes one of the most common and disabling poststroke impairments. Many contemporary rehabilitative methods target reacquisition of UE motor skills. One such intervention is mental practice (MP), which involves mental rehearsal without physical execution of the movement. MP has not been consistently integrated into clinical environments. This article discusses the scientific rationale for MPs, highlights evidence supporting their use, discusses components of the repetitive task-specific practice regimens accompanying MP, and discusses possible augmentative strategies and areas for research.


Assuntos
Medicina Baseada em Evidências , Processos Mentais , Reabilitação do Acidente Vascular Cerebral , Extremidade Superior/fisiopatologia , Humanos , Destreza Motora , Acidente Vascular Cerebral/fisiopatologia
19.
J Exp Psychol Anim Behav Process ; 30(1): 74-7, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14709117

RESUMO

Self-control is demonstrated when a less desirable immediate outcome is chosen to ensure a substantially better future. In a novel animal analogue of this situation, primary reinforcement was delivered in both the initial and terminal links of a concurrent chain schedule. Rats made initial link choices between equal amounts of ethanol-free or ethanol-containing milk. Choosing the ethanol-free reinforcer resulted in delivery of the larger terminal link reinforcer and was thus analogous to self-control. Self-control decreased as the delay between initial and terminal links increased. The results have implications for human choice situations where decisions are made between two immediately available reinforcement alternatives each associated with a different delayed outcome.


Assuntos
Consumo de Bebidas Alcoólicas , Comportamento de Escolha , Comportamento Impulsivo , Esquema de Reforço , Reforço Psicológico , Autoadministração/métodos , Animais , Masculino , Motivação , Ratos , Fatores de Tempo
20.
Appl Spectrosc ; 57(9): 1162-6, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-14611047

RESUMO

A liquid chromatography system with an inductively coupled plasma detector is used to prepare a single calibration curve that is useful for multiple analytes. The detector monitors the atomic emission from carbon at 193.09 nm. Hence, the analytes need not exhibit appreciable molar absorptivity or native fluorescence. Since the carbon signal is independent of molecular structure, the sensitivities for different compounds are similar as long as nebulization efficiencies are comparable. In fact, with a suitable internal standard, no calibration curve is necessary. The capability of the system is demonstrated with a test mixture of nine amino acids separated with a C30 reversed-phase column and a 20 mM phosphate buffered mobile phase. The system provides a detection limit of 30 ng carbon. A multi-analyte calibration curve is prepared with 135 distinct measurements: each of nine analytes, at five different concentrations, repeated in triplicate. The average relative standard deviation for 27 measurements of different amino acids at a given concentration is 2.5%. Clearly, a single analyte will suffice for the calibration of all nine test compounds. Similarly, the internal standard method provides an average percent error of 2.0% for the determination of 45 different amino acid concentrations using only a single replicate for each sample.


Assuntos
Aminoácidos/análise , Calibragem , Carbono/análise , Cromatografia Líquida de Alta Pressão/instrumentação , Gases/análise , Microquímica/instrumentação , Análise Espectral/instrumentação , Cromatografia Líquida de Alta Pressão/métodos , Desenho de Equipamento , Análise de Falha de Equipamento , Temperatura Alta , Microquímica/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Soluções , Análise Espectral/métodos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA