Coping with unobservable and mis-classified states in capture-recapture studies

Multistate mark-recapture methods provide an excellent conceptual framework for considering estimation in studies of marked animals. Traditional methods include the assumptions that (1) each state an animal occupies is observable, and (2) state is assigned correctly at each point in time. Failure of either of these assumptions can lead to biased estimates of demographic parameters. I review design and analysis options for minimizing or eliminating these biases. Unobservable states can be adjusted for by including them in the state space of the statistical model, with zero capture probability, and incorporating the robust design, or observing animals in the unobservable state through telemetry, tag recoveries, or incidental observations. Mis¿classification can be adjusted for by auxiliary data or incorporating the robust design, in order to estimate the probability of detecting the state an animal occupies. For both unobservable and mis-classified states, the key feature of the robust design is the assumption that the state of the animal is static for at least two sampling occasion

Data processing method for a weak, moving telemetry signal

Method of processing data from a spacecraft, where the carrier has a low signal-to-noise ratio and wide unpredictable frequency shifts, consists of analogue recording of the noisy signal along with a high-frequency tone that is used as a clock to trigger a digitizer

Cómo abordar los estados inobservables y clasificados incorrectamente en los estudios de captura–recaptura

Multistate mark–recapture methods provide an excellent conceptual framework for considering estimation in studies of marked animals. Traditional methods include the assumptions that (1) each state an animal occupies is observable, and (2) state is assigned correctly at each point in time. Failure of either of these assumptions can lead to biased estimates of demographic parameters. I review design and analysis options for minimizing or eliminating these biases. Unobservable states can be adjusted for by including them in the state space of the statistical model, with zero capture probability, and incorporating the robust design, or observing animals in the unobservable state through telemetry, tag recoveries, or incidental observations. Mis–classification can be adjusted for by auxiliary data or incorporating the robust design, in order to estimate the probability of detecting the state an animal occupies. For both unobservable and mis–classified states, the key feature of the robust design is the assumption that the state of the animal is static for at least two sampling occasions.Los métodos de marcaje–recaptura de estados múltiples brindan un excelente marco conceptual para considerar la estimación en los estudios de animales marcados. Los métodos tradicionales incluyen las dos hipótesis siguientes: (1) cada uno de los estados que ocupa un animal es observable; (2) el estado se asigna correctamente en cada momento. Fallos con cualquiera de estas dos hipótesis pueden traducirse en estimaciones sesgadas de parámetros demográficos. El presente estudio analiza las opciones de diseño y análisis para minimizar o eliminar estos sesgos. Los estados inobservables pueden ajustarse incluyéndolos en el espacio de estados del modelo estadístico, con cero probabilidades de captura, e incorporando el diseño robusto u observando los animales en estado inobservable mediante telemetría, recuperaciones de marcas u observaciones fortuitas. La clasificación errónea puede ajustarse mediante datos auxiliares o incorporando el diseño robusto, con objeto de estimar la probabilidad de detectar el estado que ocupa un animal. Tanto para los estados inobservables como para los clasificados erróneamente, la característica clave del diseño robusto se basa en la hipótesis de que el estado del animal es estático como mínimo en dos muestreos

Further studies of the coupled chemically reacting boundary layer and charring ablator. Part 1 - Summary Final report

Computer program development for charring ablative materials, chemically reacting laminar boundary layers, and turbulent boundary layer initiatio

Artifact Simulating Fracture on Cervical Spine Computed Tomography

We present the case of a 31-year-old trauma patient with computed tomography concerning significant C3–C4 subluxation. The abnormality is due to an artifact with which emergency physicians should be aware

Costes de los sesgos de detección en el monitoreo de poblaciones basado en índices

Managers of wildlife populations commonly rely on indirect, count–based measures of the population in making decisions regarding conservation, harvest, or control. The main appeal in the use of such counts is their low material expense compared to methods that directly measure the population. However, their correct use rests on the rarely–tested but often–assumed premise that they proportionately reflect population size, i.e., that they constitute a population index. This study investigates forest management for the endangered Red–cockaded Woodpecker (Picoides borealis) and the Wood Thrush (Hylocichla mustelina) at the Piedmont National Wildlife Refuge in central Georgia, U.S.A. Optimal decision policies for a joint species objective were derived for two alternative models of Wood Thrush population dynamics. Policies were simulated under scenarios of unbiasedness, consistent negative bias, and habitat–dependent negative bias in observed Wood Thrush densities. Differences in simulation outcomes between biased and unbiased detection scenarios indicated the expected loss in resource objectives (here, forest habitat and birds) through decision–making based on biased population counts. Given the models and objective function used in our analysis, expected losses were as great as 11%, a degree of loss perhaps not trivial for applications such as endangered species management. Our analysis demonstrates that costs of uncertainty about the relationship between the population and its observation can be measured in units of the resource, costs which may offset apparent savings achieved by collecting uncorrected population counts.Los gestores de poblaciones de fauna silvestre a menudo toman decisiones relativas a la conservación, recolección o control a partir de medidas indirectas de la población basadas en recuentos. El principal atractivo que presenta este tipo de recuentos son los bajos costes de material, en comparación con otros métodos que miden la población de forma directa. Sin embargo, el correcto uso de los mismos depende de una premisa que suele darse por sentada, aunque rara vez se comprueba, y que consiste en suponer que reflejan proporcionalmente el tamaño de la población; es decir, que constituyen un índice poblacional. El presente estudio investiga la gestión forestal de dos especies en peligro de extinción: el pájaro carpintero de cresta roja (Picoides borealis) y el zorzal mustelino (Hylocichla mustelina) en la Reserva Nacional de Animales Salvajes de Piedmont, en Georgia central, Estados Unidos. Se simularon varias políticas de conservación bajo escenarios referentes a las densidades del zorzal mustelino insesgados, con un consistente sesgo negativo y con un sesgo negativo dependiente del hábitat. Las diferencias obtenidas con respecto a los resultados de simulación entre los escenarios de detección sesgados y los no sesgados indicaron la pérdida prevista en los objetivos en materia de recursos (en este caso, el hábitat y las aves del bosque) a través de una toma de decisiones basada en los recuentos poblacionales sesgados. Teniendo en cuenta los modelos y la función de los objetivos que hemos empleado en nuestro análisis, las pérdidas previstas ascendieron al 11%, lo que supone un porcentaje bastante significativo en aplicaciones tales como la gestión de especies en peligro de extinción. Nuestro análisis demuestra que los costes de incertidumbre acerca de la relación entre la población y su observación pueden medirse en unidades del recurso dado; es posible que estos costes compensen los ahorros aparentemente conseguidos mediante la recopilación de recuentos poblacionales no corregidos

Further studies of the coupled chemically reacting boundary layer and charring ablator. Part 4 - Nonsimilar solution of an incompressible turbulent boundary layer by an integral matrix method

Nonsimilar solution of incompressible turbulent boundary layer by integral matrix metho

Performance Evaluation and Optimization of Math-Similarity Search

Similarity search in math is to find mathematical expressions that are similar to a user's query. We conceptualized the similarity factors between mathematical expressions, and proposed an approach to math similarity search (MSS) by defining metrics based on those similarity factors [11]. Our preliminary implementation indicated the advantage of MSS compared to non-similarity based search. In order to more effectively and efficiently search similar math expressions, MSS is further optimized. This paper focuses on performance evaluation and optimization of MSS. Our results show that the proposed optimization process significantly improved the performance of MSS with respect to both relevance ranking and recall.Comment: 15 pages, 8 figure

Self-care after traumatic injury and the use of the therapeutic self care scale in trauma populations

Aims: To report a correlational study of the relationship between gender, age, severity of injury, length of hospital stay and self-care behaviour in patients with traumatic injuries. Background: This study may provide a foundation for targeted nursing intervention and education programmes to help patients better recover from their injury, which is a fundamental aspect of nursing. Design: A longitudinal cohort study. Method: This study of patients hospitalized for traumatic injury was conducted from May 2006–November 2007. The Therapeutic Self Care Scale along with demographic and clinical data, were completed at 3 and 6 months after hospital discharge. Using data from the 3-month survey, the validity and reliability of the scale was calculated. Multiple regression was used to identify predictors of self-care at 3 and 6 months. Finding: Participants (n = 125) completed the questionnaire at 3 months and 103 participants completed it at 6 months. Self-care was high on both occasions and high self-care at 3 months was related to high self-care at 6 months. Older participants reported higher self-care at 3 months compared with younger patients. Factor analysis of the scale revealed three clear components; taking medication, recognition and managing symptoms and managing changes in health conditions, which explained a total of 59·8% of the variance. The 10-item revised scale was reliable. Conclusion: The findings indicate that self-care remains fairly high and stable in the first 6 months after trauma. The revised Therapeutic Self Care Scale was valid and reliable in the trauma population

Health status after traumatic injury

BACKGROUND: This study explored the relationships between health-related quality of life and postacute factors such as patients’ perceived access to information and support, perceptions of illness and ability to provide self-care after traumatic injury. METHODS: Adults (18 years or older) admitted to hospital for ≥24 hours for the acute treatment of trauma in two hospitals in Queensland, Australia, were enrolled in a prospective cohort study. Questionnaires completed at hospital discharge and 3 months and 6 months incorporated the following: demographic data; psychological factors (Revised Illness Perception Questionnaire, Information, Autonomy and Support Scale, and Therapeutic Self-Care Scale); and outcome data (medical short form-36). Data on injury and hospital stay were obtained from health care records and the Queensland Trauma Registry. RESULTS: One hundred ninety-four patients with a median Injury Severity Score 9 (interquartile range, 5–14) were enrolled, with 125 (64%) completing questionnaires at 6 months. More than half the cohort reported symptoms of pain, fatigue, stiff joints, sleep difficulties, and loss of strength. All subscale scores on the short form-36 were below Australian norms 6 months after injury. Predictors of poor physical health included older age, lower extremity injury, and increased perceived consequences of their injuries, whereas predictors of poor mental health included younger age, female gender, and lower perceived control over their environment. CONCLUSIONS: Patients with minor to moderate injury based on anatomic injury scoring systems have ongoing challenges with recovery including problematic symptoms and low quality of life. Interventions aimed toward assisting recovery should not be limited to trauma patients with major injury. LEVEL OF EVIDENCE: Prognostic study, level III