Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
1.
Ann Biomed Eng ; 50(3): 330-342, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35099657

RESUMO

Biomechanical changes after anterior cruciate ligament reconstruction (ACLR) may be detrimental to long-term knee-joint health. We used pattern recognition to characterise biomechanical differences during the landing phase of a single-leg forward hop after ACLR. Experimental data from 66 individuals 12-24 months post-ACLR (28.2 ± 6.3 years) and 32 controls (25.2 ± 4.8 years old) were input into a musculoskeletal modelling pipeline to calculate joint angles, joint moments and muscle forces. These waveforms were transformed into principal components (features), and input into a pattern recognition pipeline, which found 10 main distinguishing features (and 8 associated features) between ACLR and control landing biomechanics at significance [Formula: see text]. Our process identified known biomechanical characteristics post-ACLR: smaller knee flexion angle; less knee extensor moment; lower vasti, rectus femoris and hamstrings forces. Importantly, we found more novel and less well-understood adaptations: smaller ankle plantar flexor moment; lower soleus forces; and altered patterns of knee rotation angle, hip rotator moment and knee abduction moment. Crucially, we identified, with high certainty, subtle aberrations indicating landing instability in the ACLR group for: knee flexion and internal rotation angles and moments; hip rotation angles and moments; and lumbar rotator and bending moments. Our findings may benefit rehabilitation and assessment for return-to-sport 12-24 months post-ACLR.


Assuntos
Reconstrução do Ligamento Cruzado Anterior/reabilitação , Atividade Motora/fisiologia , Músculo Esquelético/fisiologia , Fenômenos Biomecânicos , Humanos , Resistência Física/fisiologia , Análise e Desempenho de Tarefas
2.
Ecology ; 102(3): e03273, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33368188

RESUMO

Body mass is one of the most important phenotypic attributes in animal ecology and life history. This trait is widely used in the fields of ecology and macroevolution, since it influences physiology, morphological functions, and a myriad of ecological and social interactions. In this data set, our aim was to gather a comprehensive bird and mammal body mass data set from northern South America. We report body mass, discriminated by sex, for 42,022 individual birds and 7,441 mammals representing 1,317 bird species (69% of Colombia's avifauna) and 270 mammal species (51% of Colombian mammals) from the Neotropics. The data were sourced from vouchers collected between 1942 and 2020 and from individuals captured and released at banding stations over the last two decades for birds (2000-2020) and the last decade for mammals (2010-2020), by 10 research groups and institutions in Colombia. This data set fills gaps identified in other similar databases, as it focuses on northern South America, a highly diverse Neotropical region often underrepresented in morphological data sets. We provide wide taxonomic coverage for studies interested in information both at regional and local scales. There are no copyright restrictions; the present data paper should be appropriately cited when data are used for publication. The authors would appreciate learning about research projects, teaching exercises, and other uses given to this data set and are open to contribute in further collaborations using these data.

3.
Health Promot Pract ; 22(4): 462-468, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33073618

RESUMO

Latinos are the largest minority population group in the United States, and Latino children currently account for one fourth of U.S. children under age 18. Family is a core value in the Latino culture, and fathers play a central role within the family, including making decisions that influence their children's health. Nonetheless, Latino fathers are often underrepresented in child health research. This study was designed to describe effective strategies to recruit Latino fathers into five child health research studies. Using a data recruitment log, we collected quantitative and qualitative data on recruitment strategies used to reach and enroll Latino fathers into five child health research studies from 2016 to 2020. Methods classified as direct recruitment strategies involved interaction between potential participants with research staff, whereas indirect methods involved no interaction with research staff and potential participants. In total 113 Latino fathers, majority low-income, immigrant, participated in the studies. Direct recruitment methods in combination with snowball sampling were the most successful strategies for recruiting Latino fathers, contributing to approximately 96% (n = 107) of the total participants. Indirect methods were much less effective, with social media contributing to only 3.6% (n = 4) of total participants. Not a single participant was recruited through printed materials (e.g., flyers posted or distributed). Furthermore, qualitative findings revealed the importance of culturally and linguistically relevant approaches in efforts to recruit and enroll Latino fathers. Future research should consider directly asking Latino fathers' preferences for recruitment and participation in child health research.


Assuntos
Pai , Mídias Sociais , Adolescente , Criança , Saúde da Criança , Hispânico ou Latino , Humanos , Masculino , Pobreza , Estados Unidos
4.
J Appl Biomech ; 36(4): 235-243, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32659745

RESUMO

This study compared lower-limb muscle function, defined as the contributions of muscles to center-of-mass support and braking, during a single-leg hopping task in anterior cruciate ligament-reconstructed (ACLR) individuals and uninjured controls. In total, 65 ACLR individuals and 32 controls underwent a standardized anticipated single-leg forward hop. Kinematics and ground reaction force data were input into musculoskeletal models to calculate muscle forces and to quantify muscle function by decomposing the vertical (support) and fore-aft (braking) ground reaction force components into contributions by individual lower-limb muscles. Four major muscles, the vasti, soleus, gluteus medius, and gluteus maximus, were primarily involved in support and braking in both ACLR and uninjured groups. However, although the ACLR group demonstrated lower peak forces for these muscles (all Ps < .001, except gluteus maximus, P = .767), magnitude differences in these muscles' contributions to support and braking were not significant. ACLR individuals demonstrated higher erector spinae (P = .012) and hamstrings forces (P = .085) to maintain a straighter, stiffer landing posture with more forward lumbar flexion. This altered landing posture may have enabled the ACLR group to achieve similar muscle function to controls, despite muscle force deficits. Our findings may benefit rehabilitation and the development of interventions to enable faster and safer return to sport.

5.
J Math Biol ; 80(7): 2227-2255, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32335708

RESUMO

In this paper we present a novel method for finding unknown parameters for an unknown morphogen. We postulate the existence of an unknown morphogen in a given three-dimensional domain due to the spontaneous arrangement of a downstream species on the domain boundary for which data is known. Assuming a modified Helmholtz model for the morphogen and that it is produced from a single source in the domain, our method accurately estimates the source location and other model parameters. Notably, our method does not require the forward solution of the model to be computed which can often be a challenge for three-dimensional PDE model parameter fitting. Instead, an extension is made from the problem domain to an infinite domain and the analytic nature of the fundamental solution is exploited. We explore in this manuscript strategies for best conditioning the problem and rigorously explore the accuracy of the method on two test problems. Our tests focus on the effect of source location on accuracy but also the robustness of the algorithm to experimental noise.


Assuntos
Modelos Biológicos , Morfogênese/fisiologia , Algoritmos , Animais , Conceitos Matemáticos , Transdução de Sinais/fisiologia
6.
Evol Comput ; 28(3): 379-404, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31295020

RESUMO

This article presents a method to generate diverse and challenging new test instances for continuous black-box optimization. Each instance is represented as a feature vector of exploratory landscape analysis measures. By projecting the features into a two-dimensional instance space, the location of existing test instances can be visualized, and their similarities and differences revealed. New instances are generated through genetic programming which evolves functions with controllable characteristics. Convergence to selected target points in the instance space is used to drive the evolutionary process, such that the new instances span the entire space more comprehensively. We demonstrate the method by generating two-dimensional functions to visualize its success, and ten-dimensional functions to test its scalability. We show that the method can recreate existing test functions when target points are co-located with existing functions, and can generate new functions with entirely different characteristics when target points are located in empty regions of the instance space. Moreover, we test the effectiveness of three state-of-the-art algorithms on the new set of instances. The results demonstrate that the new set is not only more diverse than a well-known benchmark set, but also more challenging for the tested algorithms. Hence, the method opens up a new avenue for developing test instances with controllable characteristics, necessary to expose the strengths and weaknesses of algorithms, and drive algorithm development.


Assuntos
Algoritmos , Benchmarking/métodos , Benchmarking/estatística & dados numéricos , Evolução Biológica , Biologia Computacional , Heurística Computacional , Análise de Componente Principal , Probabilidade , Software
7.
Emergencias (Sant Vicenç dels Horts) ; 30(3): 169-176, jun. 2018. tab, graf
Artigo em Espanhol | IBECS | ID: ibc-172957

RESUMO

OBJETIVO: Evaluar la eficiencia de cinco estrategias diagnóstico-terapéuticas posibles ante la sospecha de intoxicación aguda (IA) por paracetamol (PCT) a través de un análisis coste-efectividad, según la perspectiva del financiador en un hospital universitario terciario dotado de un programa de toxicovigilancia activa validado (SAT-HULP). MÉTODO: Estudio de análisis de coste-efectividad (ACE) de cinco alternativas diagnóstico-terapéuticas consideradas en el abordaje de los pacientes atendidos en el servicio de urgencias hospitalario (SUH) con intoxicación por PCT mediante un modelo de árbol de decisión. La población estudiada fueron los pacientes atendidos en un SUH detectados por el SAT-HULP, entre el 1/04/2011 y el 31/01/2015. Las alternativas diagnóstico-terapéuticas consideradas fueron: 1) administración sistemática de Nacetilcisteína; 2) administración del tratamiento según la dosis confirmada; 3) tratamiento según el nomograma de Rümack Matthew; 4) tratamiento según test de orina confirmado con posterior test en sangre; y 5) tratamiento según el cálculo de la semivida. Los datos correspondientes a probabilidades fueron obtenidos del programa SAT-HULP y publicaciones sobre la validación de las pruebas diagnósticas. Se realizaron análisis de sensibilidad determinístico y probabilístico. RESULTADOS: Las opciones "Tratar según dosis comunicada" y "Tratar según el nomograma" son las que muestran mejor coste-efectividad. Al compararlas, la razón coste-efectividad incremental es de 5.985,37 Euros para la primera. El análisis de sensibilidad mostró una importante dependencia del modelo a la variación de las variables principales. En el análisis de sensibilidad probabilístico la estrategia "Tratar a todos los casos" respecto a "Cálculo de semivida" obtuvo una razón coste-efectividad incremental de unos 25.111,06 Euros (DE: 1.534.420,16; intervalo: -42.136,03 a 92.358,75), resultando esta última la más eficiente. CONCLUSIONES: La estrategia "Tratar según el nomograma" es la alternativa más eficiente en el diagnóstico y tratamiento de la intoxicacióna aguda por Paracetamol en nuestro medio, no así para un escenario de mayor prevalencia e incertidumbre, donde la opción "Cálculo de semivida" se muestra como la más eficiente


OBJECTIVE: To evaluate 5 diagnostic-therapeutic strategies for suspected acute paracetamol poisoning in terms of cost-effectiveness in a tertiary university hospital with an active, validated poisoning surveillance program (SAT-HULP). METHODS: Cost-effectiveness analysis of the 5 diagnostic-therapeutic alternatives considered when attending patients with suspected paracetamol poisoning. The alternatives were chosen by means of a decision tree. We studied patients detected by the SAT-HULP program between April 1, 2011, and January 31, 2015. The diagnostic-therapeutic alternatives were as follows: 1) systematic treatment of all patients with N-acetylcysteine (NAC), 2) NAC treatment according to the reported dose; 3) NAC treatment according to a Rümack-Matthew nomogram; 4) NAC treatment according to urine test results confirmed by a blood test, and 5) treatment according to elimination half-life calculation. Probability data were obtained from the SAT-HULP program and validation studies corresponding to the diagnostic tests. Deterministic and probabilistic sensitivity analyses were performed. RESULTS: The approaches that were most cost-effective were those guided by reported doses and nomograms. The incremental cost-effectiveness of treatment according to reported dose was Euros 5985.37. The sensitivity analysis showed that the model was highly dependent on variations in the main variables; the probabilistic sensitivity analysis indicated an incremental cost-effectiveness of Euros 25 111.06 (SD, Euros 1 534 420.16; range, Euros 42 136.03-Euros 92 358.75) between the first approach (treat all cases) and last (calculate elimination half-life); half-life calculation was the more efficient. CONCLUSIONS: Treating according to nomogram was the most efficient diagnostic-therapeutic approach to treating paracetamol poisoning in our hospital. However, when the prevalence of paracetamol poisoning is higher and uncertainty is greater, it would be more efficient to treat based on calculating the half-life


Assuntos
Humanos , Acetaminofen/intoxicação , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/terapia , Farmacovigilância , Monitoramento de Medicamentos/métodos , 50303 , Serviço Hospitalar de Emergência/estatística & dados numéricos , Sistemas de Notificação de Reações Adversas a Medicamentos
8.
JMIR Public Health Surveill ; 4(1): e14, 2018 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-29382629

RESUMO

BACKGROUND: Research indicates that parents influence their children's physical activity (PA) and sedentary behaviors (SB) through their parenting styles and practices. OBJECTIVE: The objectives of this paper were to evaluate existing research examining the associations between parenting styles, parenting practices, and PA and SB among Latino children aged between 2 and 12 years, highlight limitations of the existing research, and generate suggestions for future research. METHODS: The method of this integrative review was informed by methods developed by Whittemore and Knafl, which allow for the inclusion of qualitative, quantitative, and mixed-methods studies. Using the Preferred Reporting Items for Systematic Reviews Meta-Analyses guidelines, five electronic academic databases (PubMed, SPORTDiscus, PsycINFO, PsycARTICLES, and CINAHL) were searched for peer-reviewed, full-text papers published in English. Of the 641 unique citations identified, 67 full-text papers were retrieved, and 16 were selected for review. RESULTS: The majority of the 16 reviewed studies were conducted with predominantly Mexican American or Mexican immigrant samples, and only 1 study examined the association between parenting styles and Latino children's PA and SB. Most (n=15) reviewed studies assessed the influence of parenting practices on children's PA and SB, and they provide good evidence that parenting practices such as offering verbal encouragement, prompting the child to be physically active, providing logistic support, engaging and being involved in PA, monitoring, and offering reinforcement and rewards encourage, facilitate, or increase children's PA. The examined studies also provide evidence that parenting practices, such as setting rules and implementing PA restrictions due to safety concerns, weather, and using psychological control discourage, hinder, or decrease children's PA. CONCLUSIONS: Because this review found a very small number of studies examining the relationship between parenting styles and Latino children's PA and SB, additional research is needed. Given that the majority of reviewed studies were conducted with predominantly Mexican American or Mexican immigrant samples, additional research examining parenting styles, parenting practices, and PA and SB among multiethnic Latino groups is needed to design interventions tailored to the needs of this ethnically diverse population group.

9.
Public Health Nutr ; 21(2): 403-415, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28994358

RESUMO

OBJECTIVE: Increasing evidence documents fathers' influential role in their children's eating, physical activity (PA) and sedentary behaviours (SB). We aimed to expand limited existing research examining fathers' influence in these areas by exploring Latino fathers' beliefs, attitudes and practices related to eating, PA and SB of their young children. DESIGN: Seven focus group discussions were conducted in Spanish with Latino fathers (n 28) of children aged 2-8 years. Audio recordings were transcribed and translated verbatim without identifiers. Data were analysed using thematic analysis to identify key concepts and themes using NVivo 11 software. RESULTS: Fathers expressed positive beliefs and attitudes about the importance of healthy eating for their young children, themselves and their families. Nevertheless, the majority reported familial practices including eating out, getting take-out, etc. that have been linked to increased obesity risk among Latino children. Fathers were more involved and engaged in children's PA than eating and feeding. However, several fathers reported engaging predominantly in sedentary activities with their children, appeared permissive of children's sedentary habits and struggled to set limits on children's screen-time. CONCLUSIONS: We provide new information on Latino fathers' beliefs and child feeding and PA practices that may provide important targets for interventions aimed at promoting healthful eating and PA behaviours of Latino children. Future research should further quantify the influence of Latino fathers' parenting styles and practices on development of children's eating, PA and SB. This information is needed to identify risk factors amenable to interventions and to design culturally appropriate parenting and family-based interventions targeting Latino children's home environment and designed to meet this ethnic group's specific needs.


Assuntos
Cultura , Ingestão de Alimentos/psicologia , Exercício Físico , Conhecimentos, Atitudes e Prática em Saúde , Hispânico ou Latino , Comportamento Sedentário , Adulto , Criança , Pré-Escolar , Comportamento de Escolha , Dieta Saudável/psicologia , Pai/psicologia , Grupos Focais , Preferências Alimentares/psicologia , Comportamentos Relacionados com a Saúde , Humanos , Masculino , Relações Pais-Filho , Poder Familiar/psicologia , Pesquisa Qualitativa , Fatores Socioeconômicos
10.
Evol Comput ; 25(4): 529-554, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27689468

RESUMO

This article presents a method for the objective assessment of an algorithm's strengths and weaknesses. Instead of examining the performance of only one or more algorithms on a benchmark set, or generating custom problems that maximize the performance difference between two algorithms, our method quantifies both the nature of the test instances and the algorithm performance. Our aim is to gather information about possible phase transitions in performance, that is, the points in which a small change in problem structure produces algorithm failure. The method is based on the accurate estimation and characterization of the algorithm footprints, that is, the regions of instance space in which good or exceptional performance is expected from an algorithm. A footprint can be estimated for each algorithm and for the overall portfolio. Therefore, we select a set of features to generate a common instance space, which we validate by constructing a sufficiently accurate prediction model. We characterize the footprints by their area and density. Our method identifies complementary performance between algorithms, quantifies the common features of hard problems, and locates regions where a phase transition may lie.


Assuntos
Algoritmos , Simulação por Computador
11.
J Biomech ; 47(12): 2863-8, 2014 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-25129166

RESUMO

The aim of this paper was to compare the effect of different optimisation methods and different knee joint degrees of freedom (DOF) on muscle force predictions during a single legged hop. Nineteen subjects performed single-legged hopping manoeuvres and subject-specific musculoskeletal models were developed to predict muscle forces during the movement. Muscle forces were predicted using static optimisation (SO) and computed muscle control (CMC) methods using either 1 or 3 DOF knee joint models. All sagittal and transverse plane joint angles calculated using inverse kinematics or CMC in a 1 DOF or 3 DOF knee were well-matched (RMS error<3°). Biarticular muscles (hamstrings, rectus femoris and gastrocnemius) showed more differences in muscle force profiles when comparing between the different muscle prediction approaches where these muscles showed larger time delays for many of the comparisons. The muscle force magnitudes of vasti, gluteus maximus and gluteus medius were not greatly influenced by the choice of muscle force prediction method with low normalised root mean squared errors (<48%) observed in most comparisons. We conclude that SO and CMC can be used to predict lower-limb muscle co-contraction during hopping movements. However, care must be taken in interpreting the magnitude of force predicted in the biarticular muscles and the soleus, especially when using a 1 DOF knee. Despite this limitation, given that SO is a more robust and computationally efficient method for predicting muscle forces than CMC, we suggest that SO can be used in conjunction with musculoskeletal models that have a 1 or 3 DOF knee joint to study the relative differences and the role of muscles during hopping activities in future studies.


Assuntos
Articulação do Joelho/fisiologia , Modelos Biológicos , Movimento/fisiologia , Músculo Esquelético/fisiologia , Adulto , Fenômenos Biomecânicos , Quadril/fisiologia , Humanos , Joelho/fisiologia , Perna (Membro)/fisiologia , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...