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3.
Comput Struct Biotechnol J ; 21: 4914-4922, 2023.
Article in English | MEDLINE | ID: mdl-37867974

ABSTRACT

The nematode Caenorhabditis elegans (C. elegans) is of significant interest for research into neurodegenerative diseases, aging, and drug screening. However, conducting these assays manually is a tedious and time-consuming process. This paper proposes a methodology to achieve a generalist C. elegans detection algorithm, as previous work only focused on dataset-specific detection, tailored exclusively to the characteristics and appearance of the images in a given dataset. The main aim of our study is to achieve a solution that allows for robust detection, regardless of the image-capture system used, with the potential to serve as a basis for the automation of numerous assays. These potential applications include worm counting, worm tracking, motion detection and motion characterization. To train this model, a dataset consisting of a wide variety of appearances adopted by C. elegans has been curated and dataset augmentation methods have been proposed and evaluated, including synthetic image generation. The results show that the model achieves an average precision of 89.5% for a wide variety of C. elegans appearances that were not used during training, thereby validating its generalization capabilities.

4.
Nature ; 613(7943): 298-302, 2023 01.
Article in English | MEDLINE | ID: mdl-36631652

ABSTRACT

Bed load sediment transport, in which wind or water flowing over a bed of sediment causes grains to roll or hop along the bed, is a critically important mechanism in contexts ranging from river restoration1 to planetary exploration2. Despite its widespread occurrence, predictions of bed load sediment flux are notoriously imprecise3,4. Many studies have focused on grain size variability5 as a source of uncertainty, but few have investigated the role of grain shape, even though shape has long been suspected to influence transport rates6. Here we show that grain shape can modify bed load transport rates by an amount comparable to the scatter in many sediment transport datasets4,7,8. We develop a theory that accounts for grain shape effects on fluid drag and granular friction and predicts that the onset and efficiency of transport depend on the coefficients of drag and bulk friction of the transported grains. Laboratory experiments confirm these predictions and reveal that the effect of grain shape on sediment transport can be difficult to intuit from the appearance of grains. We propose a shape-corrected sediment transport law that collapses our experimental measurements. Our results enable greater accuracy in predictions of sediment transport and help reconcile theories developed for spherical particles with the behaviour of natural sediment grains.

5.
J. inborn errors metab. screen ; 4: e150013, 2016. tab
Article in English | LILACS-Express | LILACS | ID: biblio-1090908

ABSTRACT

Abstract Newborn screening for the detection of inborn errors of metabolism (IEM), endocrinopathies, hemoglobinopathies, and other disorders is a public health initiative aimed at identifying specific diseases in a timely manner. Mexico initiated newborn screening in 1973, but the national incidence of this group of diseases is unknown or uncertain due to the lack of large sample sizes of expanded newborn screening (ENS) programs and lack of related publications. The incidence of a specific group of IEM, endocrinopathies, hemoglobinopathies, and other disorders in newborns was obtained from a Mexican hospital. These newborns were part of a comprehensive ENS program at Ginequito (a private hospital in Mexico), from January 2012 to August 2014. The retrospective study included the examination of 10 000 newborns' results obtained from the ENS program (comprising the possible detection of more than 50 screened disorders). The findings were the following: 34 newborns were confirmed with an IEM, endocrinopathies, hemoglobinopathies, or other disorders and 68 were identified as carriers. Consequently, the estimated global incidence for those disorders was 3.4 in 1000 newborns; and the carrier prevalence was 6.8 in 1000. Moreover, a 0.04% false-positive rate was unveiled as soon as diagnostic testing revealed negative results. The most frequent diagnosis was glucose-6-phosphate dehydrogenase deficiency; and in the case of carriers, it was hemoglobinopathies. The benefit of the ENS is clear as it offers prompt treatment on the basis of an early diagnosis including proper genetic counseling. Furthermore, these results provide a good estimation of the frequencies of different forms of newborn IEM, endocrinopathies, hemoglobinopathies, and other disorders at Ginequito.

6.
Nutr. hosp ; 32(3): 1116-1121, sept. 2015. ilus, tab
Article in Spanish | IBECS | ID: ibc-142475

ABSTRACT

Introducción: estudios consistentes durante los últimos años han caracterizado la relación entre la desnutrición calórico-proteica (DCP) y el desarrollo de enfermedades no transmisibles en la adultez, como el Síndrome Metabólico (SM). Objetivo: analizar la relación entre SM en la adultez y la DCP durante los primeros 1.000 días de vida en una cohorte de adultos recientemente generada en Curicó, Chile. Material y métodos: se analizaron 49 sujetos adultos jóvenes que durante sus primeros dos años de vida sufrieron desnutrición calórico-proteica moderada a severa mediante la realización de antropometría, medición de la presión arterial y exámenes de laboratorio. Se determinó la prevalencia del SM y la carga de sus atributos. Resultados: se obtuvo una prevalencia de SM del 14,3% sin diferencias significativas por género, con una asociación directa y notable entre la carga de SM, el índice de masa corporal (IMC), el índice cintura/talla, presión arterial y niveles plasmáticos de glicemia y triglicé- ridos (TG), y una asociación inversa con colesterol HDL. Conclusión: la presión arterial sistólica y el valor plasmático de TG representaron los factores de riesgo más importantes del SM en esta cohorte. No se encontró asociación entre la DCP en los 1.000 primeros días de vida y el SM en la adultez (AU)


Background: during recent years consistent studies have characterized the relationship between moderate and severe protein-calorie malnutrition and the appearance of non-communicable diseases in adulthood like metabolic syndrome (MS). Aim: to analyze the relationship between moderate and severe protein-calorie malnutrition during the first 1 000 days of life and the MS in a cohort of adults from Curicó, Chile. Material and methods: we studied 49 young adults who had suffered moderate to severe protein-calorie malnutrition during their first two years of life. Anthropometry, blood pressure measurement and laboratory tests were performed, and the burden of MS attributes was determined. Results: the prevalence of MS was 14.3% with no significant differences by gender, showing a direct and significant association between burden of MS and body mass index, waist / height index, blood pressure, plasma levels of glucose and triglyceride, and an inverse association with HDL. Conclusion: systolic blood pressure and plasma level of triglyceride represented the most important risk factors for SM in this cohort. We found no association between the presence of protein-calorie malnutrition and MS (AU)


Subject(s)
Humans , Infant , Young Adult , Protein-Energy Malnutrition/epidemiology , Metabolic Syndrome/epidemiology , Child Nutrition Disorders/complications , Cohort Studies , Risk Factors
7.
Nutr Hosp ; 32(3): 1116-21, 2015 Sep 01.
Article in Spanish | MEDLINE | ID: mdl-26319828

ABSTRACT

BACKGROUND: during recent years consistent studies have characterized the relationship between moderate and severe protein-calorie malnutrition and the appearance of non-communicable diseases in adulthood like metabolic syndrome (MS). AIM: to analyze the relationship between moderate and severe protein-calorie malnutrition during the first 1 000 days of life and the MS in a cohort of adults from Curicó, Chile. MATERIAL AND METHODS: we studied 49 young adults who had suffered moderate to severe protein-calorie malnutrition during their first two years of life. Anthropometry, blood pressure measurement and laboratory tests were performed, and the burden of MS attributes was determined. RESULTS: the prevalence of MS was 14.3% with no significant differences by gender, showing a direct and significant association between burden of MS and body mass index, waist / height index, blood pressure, plasma levels of glucose and triglyceride, and an inverse association with HDL. CONCLUSION: systolic blood pressure and plasma level of triglyceride represented the most important risk factors for SM in this cohort. We found no association between the presence of protein-calorie malnutrition and MS.


Introducción: estudios consistentes durante los últimos años han caracterizado la relación entre la desnutrición calórico-proteica (DCP) y el desarrollo de enfermedades no transmisibles en la adultez, como el Síndrome Metabólico (SM). Objetivo: analizar la relación entre SM en la adultez y la DCP durante los primeros 1.000 días de vida en una cohorte de adultos recientemente generada en Curicó, Chile. Material y métodos: se analizaron 49 sujetos adultos jóvenes que durante sus primeros dos años de vida sufrieron desnutrición calórico-proteica moderada a severa mediante la realización de antropometría, medición de la presión arterial y exámenes de laboratorio. Se determinó la prevalencia del SM y la carga de sus atributos. Resultados: se obtuvo una prevalencia de SM del 14,3% sin diferencias significativas por género, con una asociación directa y notable entre la carga de SM, el índice de masa corporal (IMC), el índice cintura/talla, presión arterial y niveles plasmáticos de glicemia y triglicéridos (TG), y una asociación inversa con colesterol HDL. Conclusión: la presión arterial sistólica y el valor plasmático de TG representaron los factores de riesgo más importantes del SM en esta cohorte. No se encontró asociación entre la DCP en los 1.000 primeros días de vida y el SM en la adultez.


Subject(s)
Metabolic Syndrome/etiology , Metabolic Syndrome/metabolism , Nutritional Status , Protein-Energy Malnutrition/complications , Protein-Energy Malnutrition/epidemiology , Age Factors , Biomarkers , Body Mass Index , Body Weights and Measures , Child, Preschool , Chile/epidemiology , Female , Humans , Infant , Infant, Newborn , Male , Metabolic Syndrome/epidemiology , Prevalence , Risk Factors , Young Adult
8.
Phys Rev E Stat Nonlin Soft Matter Phys ; 90(5-1): 051003, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25493730

ABSTRACT

We demonstrate that systems with a parameter-controlled inverse cascade can exhibit critical behavior for which at the critical value of the control parameter the inverse cascade stops. In the vicinity of such a critical point, standard phenomenological estimates for the energy balance will fail since the energy flux towards large length scales becomes zero. We demonstrate this using the computationally tractable model of two-dimensional (2D) magnetohydrodynamics in a periodic box. In the absence of any external magnetic forcing, the system reduces to hydrodynamic fluid turbulence with an inverse energy cascade. In the presence of strong magnetic forcing, the system behaves as 2D magnetohydrodynamic turbulence with forward energy cascade. As the amplitude of the magnetic forcing is varied, a critical value is met for which the energy flux towards the large scales becomes zero. Close to this point, the energy flux scales as a power law with the departure from the critical point and the normalized amplitude of the fluctuations diverges. Similar behavior is observed for the flux of the square vector potential for which no inverse flux is observed for weak magnetic forcing, while a finite inverse flux is observed for magnetic forcing above the critical point. We conjecture that this behavior is generic for systems of variable inverse cascade.

9.
Rev. bras. ecocardiogr. imagem cardiovasc ; 24(3): 31-36, jul.-set. 2011. ilus, tab
Article in Portuguese | LILACS | ID: lil-592436

ABSTRACT

Introdução: É bastante conhecido que a cardiopatia congênita está relacionada à síndrome de Down. Entretanto, existem raros relatos de casos de displasia valvar em crianças portadoras de síndrome de Down, sem cardiopatia associada. Objetivos: Verificar a presença e magnitude de alterações nas valvas atrioventriculares, em pacientes com diagnóstico de síndrome de Down, sem cardiopatia congênita associada. Método: Foi realizado um estudo transversal, com captação prospectiva de 162 pacientes, avaliados pela ecocardiografia, classificados em Grupo 1, portadores de Síndrome de Down (n = 81) e Grupo 2, crianças normais, do ponto de vista genético e cardiológico (n = 81). Resultados: A frequência de displasia das valvas tricúspide e mitral foi superior no grupo 01, quando comparado ao grupo 2 (55 versus 0, p<0,00001 e 20 versus 2, p < 0,0001, respectivamente). No grupo 1, 19 crianças apresentaram comprometimento simultâneo das valvas tricúspide e mitral. O comprometimento isolado da valva tricúspide ocorreu em 36 casos e da valva mitral ocorreu em apenas 01 caso (p < 0,01). Vinte e cinco crianças do Grupo 1 tinham ambas as valvas normais. Conclusão: Este estudo descreveu, pela primeira vez, a alta frequência de displasia nas válvulas tricúspide e mitral, em crianças e adolescentes com síndrome de Down, sem doença cardíaca congênita.


Introduction: It is well known that congenital heart disease is related to Down syndrome, however there are rare reports of valvular dysplasia in children with Down syndrome without associated congenital heart disease. Objectives: To determine the presence and magnitude of changes in atrioventricular valves in patients with Down’s syndrome without associated congenital heart diseases. Methods: We conducted a prospective cross-sectional study of 162 patients assessed by echocardiography, classifi edin Group 1, patients with Down syndrome (n = 81) and Group 2, genetically normal children without congenital heart disease. (n=81). Results: Th e frequency of dysplasia of tricuspid and mitral valves was higher in the group 1 compared to group 2 (55 vs 0, p <0.00001 and 20 versus 2, p <0.0001, respectively). In group 1, 19 children had simultaneous involvement of the tricuspid and mitral valves. Th e isolated involvement of the tricuspid valve occurred in 36 cases and isolated involvement of the mitral valve inonly one case (p <0.01). Twenty-fi ve children in a group containing both normal valves. Conclusion: To our knowledge, this study described for the fi rst time the high frequency of dysplasia in the tricuspid and mitral valves in children with Down’s syndromewithout congenital heart disease.


Subject(s)
Humans , Infant , Child, Preschool , Child , Adolescent , Echocardiography/methods , Down Syndrome/complications , Heart Valves/abnormalities , Child
10.
Rev. chil. nutr ; 29(2): 78-85, ago. 2002. tab
Article in Spanish | LILACS | ID: lil-340271

ABSTRACT

El mundo ha progresado notoriamente en la solución de los problemas nutricionales, de mortalidad infantil e infecciosos. En Latinoamérica, Chile ha sido el que más ha mejorado estos indicadores, lo que explicaría la rápida transición epidemiológica que han experimentado. Sin embargo han aumentado los problemas nutricionales por exceso, con un considerable aumento de las enfermedades crónicas no transmisibles del adulto, las que constituyen actualmente la principal causa de muerte en el país. El desafío actual es disminuir la obesidad sin aumentar la desnutrición, la que actualmente es una enfermedad latente. En los últimos años la disminución del retraso estatural ha sido menos notoria que el aumento de la obesidad y la disminución de la desnutrición, lo que podría deberse a algún déficit de micronutrientes o bien visualizarse mejor al no existir déficits de macronutrientes


Subject(s)
Humans , Male , Child, Preschool , Adolescent , Female , Nutrition Disorders , Obesity , Body Mass Index , Chile , Chronic Disease/epidemiology , Failure to Thrive , Nutritional Status
12.
Rev. chil. nutr ; 29(1): 62-63, abr. 2002. tab
Article in Spanish | LILACS | ID: lil-340287

ABSTRACT

Se describe la evolución de la nutrición de yodo en el escolar chileno perteneciente a 4 zonas censorias del país, destacando la excesiva excreción urinaria de yodo a pesar que el Reglamento Sanitario de los Alimentos disminuyó el año 2000 la concentración de yodo en la sal de 100 ppm a un rango de 20 a 60 ppm. Nos interesó profundizar porque no disminuyeron las yodurias en los escolares. Para ello se midió el contenido de yodo en el pan, por tener un alto consumo en Chile (en promedio 250 g por día). En diferentes tipos de pan se determinó la concentración de yodo que fue alrededor de 0.5 ug/g, valor 10 veces mas alta que las concentraciones en Inglaterra y España. Sin embargo se estimó que el consumo de pan en Chile aportaría alrededor de 130 ug I/día, lo que no explicaría totalmente las altas cifras de excreción de yodo actuales. De importancia es continuar indagando las causas de este alto consumo para evitar sus posibles complicaciones


Subject(s)
Humans , Child , Bread , Iodine , Infant Nutrition , Food Analysis , Iodine , Micronutrients , Thyroiditis, Autoimmune
13.
Rev. chil. nutr ; 28(1): 149-58, abr. 2001. tab, graf
Article in Spanish | LILACS | ID: lil-290227

ABSTRACT

Este artículo revisa los actuales conceptos sobre los mecanismos de la formación de la caries dental y la influencia de la presencia de fluoruro (F) en la cavidad oral especialmente en el fluido de la placa y en los procesos de remineralización. Se comenta un esquema sencillo del metabolismo del fluoruro junto a algunos conceptos nuevos sobre la influencia de la edad y de las dosis diarias de F en la retención corporal y excreción renal de F


Subject(s)
Humans , Dental Caries/prevention & control , Fluorine/therapeutic use , Cariostatic Agents/therapeutic use , Dentifrices/analysis , Fluorine/metabolism
14.
Rev. chil. nutr ; 28(1): 159-67, abr. 2001.
Article in Spanish | LILACS | ID: lil-290228

ABSTRACT

Este artículo analiza tanto los efectos beneficiosos como las posibles reacciones adversas que puede ocasionar el fluoruro (F). Se describen los países que usan sal fluorurada, el muy adecuado costo beneficio de esta suplementación, la concentración ideal de F que debe contener la sal (250 a 350 ppm), la utilidad de una elección individual o cobertura completa de esta medida en la salud dental poblacional y las técnicas de fluoruración de la sal. Se relatan las dificultades para obtener una adecuada suplementación con F que han tenido algunos países y la efectividad obtenida con la sal fluorurada en diferentes países. Luego se analizan los posibles efectos adversos de la suplementación con F para finalizar analizando las ventajas de la fluoruración de la leche al focalizar la medida al grupo que mas se beneficia con esta medida


Subject(s)
Humans , Dental Caries/prevention & control , Fluorine/therapeutic use , Sodium Chloride, Dietary/administration & dosage , Fluorine/adverse effects , Fluoridation/methods , Food, Fortified , Milk
15.
Rev. chil. nutr ; 28(1): 169-76, abr. 2001.
Article in Spanish | LILACS | ID: lil-290229

ABSTRACT

En este artículo se revisa la evolución de la suplementación de fluoruros a nivel poblacional a través del agua potable y su efecto en la prevalencia de caries dental y en el riesgo de fluorosis dental. Se analiza el estado actual de la fluoruración del agua potable en el mundo y el costo de este proceso. Se termina el artículo analizando las alternativas de suplementación con F a comunidades pequeñas


Subject(s)
Humans , Dental Caries/prevention & control , Fluorine/therapeutic use , Fluoridation/methods , Water Purification
16.
Rev. chil. nutr ; 28(supl.1): 57-70, ene. 2001. tab, graf
Article in Spanish | LILACS | ID: lil-340265

ABSTRACT

Se analizan los factores que inciden en la mineralización ósea (MO) del niño y del adolescente. Se detallan especialmente los factores nutricionales, describiendo los requerimientos de calcio y vitamina D, la ingesta de calcio del escolar chileno, la biodisponibilidad del calcio, la influencia de la ingesta de calcio en la MO y los efectos de una suplementación con calcio y vitamina D en la densidad mineral ósea, tomando como modelo la enfermedad celíaca. Se describe la influencia del peso de nacimiento, la actividad física y del estado de salud en la MO. Además se analizan todos los factores que influyen en la MO del adulto


Subject(s)
Humans , Male , Child, Preschool , Adolescent , Female , Calcification, Physiologic , Child Development , Nutritional Requirements , Adolescent Nutrition , Biological Availability , Birth Weight , Calcium , Calcium, Dietary , Dietary Supplements , Celiac Disease/etiology , Risk Factors , Vitamin D
18.
In. Albala Brevis, Cecilia; Kain B., Juliana; Burrows Argote, Raquel; Díaz Bustos, Erik. Obesidad: un desafío pendiente. Santiago de Chile, Universitaria, 2000. p.130-41, tab.
Monography in Spanish | LILACS | ID: lil-284853
19.
Rev. chil. nutr ; 26(3): 311-5, dic. 1999. tab
Article in Spanish | LILACS | ID: lil-286849

ABSTRACT

Se analiza el cambio en la prevalencia del exceso de peso escolar durante los últimos años en Chile. Detectamos que de 1986 a 1994 se ha producido un notorio incremento del sobrepeso (IMC entre el percertilo 85 y 95) de 9.5 y 10.4 a 16.6 y 19.8 por ciento en varones prepúberes y púberes respectivamente y de 9.9 y 10.3 a 14.5 y 17.0 por ciento en mujeres prepúberes y púberes respectivamente. La obesidad (IMC sobre el percentilo 95) también ha experimentado un notorio incremento de 5.9 y 4.0 a 13.5 y 13.4 por ciento en varones prepúberes y púberes respectivamente y de 6.4 y 4.8 a 12.9 y 16.7 por ciento en mujeres prepúberes y púberes respectivamente. Se discute la importancia de estos hallazgos en el aumento de las enfermedades cardiovasculares, diabetes tipo 2 y síndrome X en el adulto y la necesidad de implementar medidas para solucionar este problema


Subject(s)
Humans , Female , Male , Adolescent , Obesity/epidemiology , Weight Gain , Body Mass Index , Chile/epidemiology , Residence Characteristics/statistics & numerical data , Nutritional Status , Prevalence , Sex Distribution , Weight by Height
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