Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
2.
Plant Methods ; 14: 49, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29946344

RESUMEN

BACKGROUND: Grain yield, ear and kernel attributes can assist to understand the performance of maize plant under different environmental conditions and can be used in the variety development process to address farmer's preferences. These parameters are however still laborious and expensive to measure. RESULTS: A low-cost ear digital imaging method was developed that provides estimates of ear and kernel attributes i.e., ear number and size, kernel number and size as well as kernel weight from photos of ears harvested from field trial plots. The image processing method uses a script that runs in a batch mode on ImageJ; an open source software. Kernel weight was estimated using the total kernel number derived from the number of kernels visible on the image and the average kernel size. Data showed a good agreement in terms of accuracy and precision between ground truth measurements and data generated through image processing. Broad-sense heritability of the estimated parameters was in the range or higher than that for measured grain weight. Limitation of the method for kernel weight estimation is discussed. CONCLUSION: The method developed in this work provides an opportunity to significantly reduce the cost of selection in the breeding process, especially for resource constrained crop improvement programs and can be used to learn more about the genetic bases of grain yield determinants.

3.
Theor Appl Genet ; 125(4): 759-71, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22566067

RESUMEN

The availability of high density panels of molecular markers has prompted the adoption of genomic selection (GS) methods in animal and plant breeding. In GS, parametric, semi-parametric and non-parametric regressions models are used for predicting quantitative traits. This article shows how to use neural networks with radial basis functions (RBFs) for prediction with dense molecular markers. We illustrate the use of the linear Bayesian LASSO regression model and of two non-linear regression models, reproducing kernel Hilbert spaces (RKHS) regression and radial basis function neural networks (RBFNN) on simulated data and real maize lines genotyped with 55,000 markers and evaluated for several trait-environment combinations. The empirical results of this study indicated that the three models showed similar overall prediction accuracy, with a slight and consistent superiority of RKHS and RBFNN over the additive Bayesian LASSO model. Results from the simulated data indicate that RKHS and RBFNN models captured epistatic effects; however, adding non-signal (redundant) predictors (interaction between markers) can adversely affect the predictive accuracy of the non-linear regression models.


Asunto(s)
Genoma de Planta/genética , Redes Neurales de la Computación , Zea mays/genética , Teorema de Bayes , Simulación por Computador , Bases de Datos Genéticas , Ambiente , Flores/genética , Flores/fisiología , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Carácter Cuantitativo Heredable , Zea mays/microbiología
4.
Trans Ophthalmol Soc U K (1962) ; 104 ( Pt 2): 142-5, 1985.
Artículo en Inglés | MEDLINE | ID: mdl-3857774

RESUMEN

In most reported series of trabeculectomy results a failure rate of 10 to 15 per cent is quoted. It seems likely that some, perhaps the majority of these failures are due to conjunctival or tenon scarring. If a method of trabeculectomy could be devised so that the conjunctiva and tenon's capsule were not injured, the failure rate might be reduced. The clear-cornea approach has been developed with this in mind. The rational basis, the surgical method and results in a small number of cases will be described.


Asunto(s)
Córnea/cirugía , Glaucoma de Ángulo Abierto/cirugía , Malla Trabecular/cirugía , Humanos , Métodos
5.
Trans Ophthalmol Soc U K (1962) ; 103 ( Pt 1): 39-41, 1983.
Artículo en Inglés | MEDLINE | ID: mdl-6581633

RESUMEN

The surgical treatment of open angle glaucoma in eyes expected to have an unsuccessful result from trabeculectomy is considered. It is concluded that the long-tube implant of Molteno is currently the method of choice. The rationale of the method is discussed. The technique is described.


Asunto(s)
Drenaje/métodos , Glaucoma de Ángulo Abierto/cirugía , Drenaje/instrumentación , Humanos
6.
Trans Ophthalmol Soc U K (1962) ; 103 ( Pt 3): 297-312, 1983.
Artículo en Inglés | MEDLINE | ID: mdl-6200965

RESUMEN

Dissatisfaction with other forms of treatment in the neovascular and other 'difficult' glaucomas led the authors to use the Molteno long tube implant. This paper resulted from a review of the results obtained in 30 cases over the past four years. The patients fell naturally into the two groups of neovascular and non-neovascular glaucomas. The eyes with neovascular glaucoma had an implant used early in the disease process, while the eyes with non-neovascular glaucoma tended to have the implant used as a last resort, after the failure of conventional techniques. An overall success rate of 63 per cent was found and this could be subdivided into success rates of 50 per cent for the non-neovascular group and of 75 per cent for the neovascular group. These findings probably reflect the late or early use of the implant in the disease process. The results confirm the authors' clinical impression that the Molteno long tube implant is a useful tool in the management of these glaucomas, and that for optimal results it should be considered early in the condition.


Asunto(s)
Glaucoma/cirugía , Prótesis e Implantes , Adolescente , Adulto , Anciano , Cámara Anterior/cirugía , Antifibrinolíticos/efectos adversos , Antifibrinolíticos/uso terapéutico , Glaucoma/tratamiento farmacológico , Glaucoma/fisiopatología , Humanos , Persona de Mediana Edad , Neovascularización Patológica/fisiopatología , Complicaciones Posoperatorias , Vasos Retinianos/fisiopatología
7.
Trans Ophthalmol Soc U K (1962) ; 101(1): 184-5, 1981.
Artículo en Inglés | MEDLINE | ID: mdl-6192561

RESUMEN

The pathological physiology of neovascular glaucoma is discussed. Various methods of treatment are examined in the light of the theory of causation. The conclusion is drawn that drainage surgery is the most promising of the alternatives. Since conventional drainage surgery is not effective, it is suggested that the long-tube implant of Molteno is the treatment of choice. Results and complications in ten cases are presented.


Asunto(s)
Glaucoma/terapia , Neovascularización Patológica/terapia , Atropina/uso terapéutico , Drenaje/métodos , Glaucoma/etiología , Humanos , Fotocoagulación , Neovascularización Patológica/etiología , Vasos Retinianos/cirugía
9.
Nurs Mirror Midwives J ; 140(20): 53-5, 1975 May.
Artículo en Inglés | MEDLINE | ID: mdl-1039703
12.
J Virol ; 10(6): 1130-5, 1972 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-4345492

RESUMEN

The temperature dependence of the virion-associated polymerase activity of six temperature-sensitive (ts) mutants of vesicular stomatitis virus (tsW10, 11, 14, 16B, 28, and 29) has been examined in vitro and compared to the heat-resistant parent (HR). The polymerase of five of the mutants (tsW10, 11, 14, 16B, and 28) appears to be significantly more ts than that of HR. Because certain pairs of these five mutants can complement each other's in vitro polymerase activity, it appears that in vitro some components involved in the polymerase of one virion can be utilized by another virion. Examination of 19 revertants of tsW11 and tsW16B which had regained their ability to replicate at 38 C showed that their in vitro polymerase activity had also become less ts. Furthermore, it was found that the pairs of mutants which showed in vitro complementation of polymerase activity at 38 C were those which had shown complementation in yielding infectious progeny in mixedly infected cells. These two observations suggest that the ts behavior of the in vitro polymerase activity of the five mutants is related to their inability to replicate at the nonpermissive temperature.


Asunto(s)
ARN Polimerasas Dirigidas por ADN/metabolismo , Virus de la Estomatitis Vesicular Indiana/enzimología , Animales , Sistema Libre de Células , Centrifugación por Gradiente de Densidad , Centrifugación Zonal , Prueba de Complementación Genética , Guanosina Trifosfato/metabolismo , Células L , Ratones , Mutación , ARN Viral/biosíntesis , Temperatura , Tritio , Virus de la Estomatitis Vesicular Indiana/crecimiento & desarrollo , Virus de la Estomatitis Vesicular Indiana/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA