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Int J Cardiovasc Imaging ; 34(1): 131-140, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28733755


Native T1 value is emerging as a reliable indicator of abnormal heart conditions related to myocardial fibrosis. Investigators have extensively used the standardized myocardial segmentation of the American Heart Association (AHA) to measure regional T1 values of the left ventricular (LV) walls. In this paper, we present a fully automatic system to analyze modified Look-Locker inversion recovery images and to report regional T1 values of AHA segments. Ten healthy individuals participated in the T1 mapping study with a 3.0 T scanner after providing informed consent. First, we obtained masks of an LV blood-pool region and LV walls by using an image synthesis method and a layer-growing method. Subsequently, the LV walls were divided into AHA segments by identifying the boundaries of the septal regions and by using a radial projection method. The layer-growing method significantly enhanced the accuracy of the derived myocardium mask. We compared the T1 values that were obtained using manual region of interest selections and those obtained using the automatic system. The average T1 difference of the calculated segments was 4.6 ± 1.5%. This study demonstrated a practical and robust method of obtaining native T1 values of AHA segments in LV walls.

Ventrículos do Coração/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/métodos , Imagem por Ressonância Magnética/métodos , Miocárdio , Função Ventricular Esquerda , Adulto , Automação , Voluntários Saudáveis , Humanos , Masculino , Valor Preditivo dos Testes , Adulto Jovem
Front Physiol ; 8: 208, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28428760


To understand dynamic changes in polyamines (PAs) forms and components of polyamine metabolism in zoysiagrass (Zoysia japonica Steud.) response to salt stress with exogenous spermidine (Spd) application, two Chinese zoysia cultivars, z081 and z057, were exposed to sodium chloride stress for 2, 4, 6, and 8 days. The z057 cultivar possesses higher salinity tolerance than the z081 cultivar. Salt stress decreased the zoysiagrass fresh weight (FW) and increased free Spd and spermine (Spm) levels and soluble and insoluble putrescine (Put), Spd and Spm levels in both cultivars. Moreover, salt stress enhanced the activities of arginine decarboxylase (ADC), ornithine decarboxylase (ODC), S-adenosylmethionine decarboxylase (SAMDC), and diamine oxidase (DAO). Exogenous Spd increased PA metabolism and ADC, SAMDC, and DAO activities and decreased free Put levels under salt stress conditions in both cultivars. In addition, structural equation modeling (SEM) showed that ODC, SAMDC, and DAO contributed to PA metabolism, and endogenous Spd levels also contributed to endogenous Spm levels. Free PAs may be the primary factor influencing the variation of other PA forms. SEM also indicated that ADC and polyamine oxidase (PAO) play a limited role in enhancing zoysia salt tolerance via PA metabolism under salt stress.

Phytopathology ; 106(11): 1319-1325, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27454703


Lettuce (Lactuca sativa L.) is a diploid (2n = 18) with a genome size of 2,600 Mbp, and belongs to the family Compositae. Bacterial leaf spot (BLS), caused by Xanthomonas campestris pv. vitians, is a major disease of lettuce worldwide. Leaf lettuce PI 358001-1 has been characterized as an accession highly resistant to BLS and has white seed. In order to understand inheritance of the high resistance in this germplasm line, an F3 population consisting of 163 families was developed from the cross PI 358001-1 × 'Tall Guzmaine' (a susceptible Romaine lettuce variety with black seed). The segregation ratio of reaction to disease by seedling inoculation with X. campestris pv. vitians L7 strain in the F3 families was shown to be 32:82:48 homozygous resistant/heterozygous/homozygous susceptible, fitting to 1:2:1 (n = 162, χ2 = 3.19, P = 0.20). The segregation ratio of seed color by checking F2 plants was 122:41 black/white, fitting to 3:1 (n = 163, χ2 = 0.002, P = 0.96). The results indicated that both BLS resistance and seed color were inherited as a dominant gene mode. A genetic linkage map based on 124 randomly selected F2 plants was developed to enable molecular mapping of the BLS resistance and the seed color trait. In total, 199 markers, comprising 176 amplified fragment length polymorphisms, 16 simple-sequence repeats, 5 resistant gene candidate markers, and 2 cleaved amplified polymorphic sequences (CAPS) markers were assigned to six linkage groups. The dominant resistance gene to BLS (Xcvr) was mapped on linkage group 2 and the gene locus y for seed color was identified on linkage group 5. Due to the nature of a single gene inheritance, the high-resistance gene should be readily transferred to adapted lettuce cultivars to battle against the devastating disease of lettuce.

Resistência à Doença/genética , Alface/genética , Doenças das Plantas/imunologia , Xanthomonas campestris/fisiologia , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Mapeamento Cromossômico , Ligação Genética , Alface/imunologia , Alface/microbiologia , Repetições de Microssatélites/genética , Fenótipo , Doenças das Plantas/microbiologia , Folhas de Planta/genética , Folhas de Planta/imunologia , Folhas de Planta/microbiologia , Sementes/genética , Sementes/imunologia , Sementes/microbiologia
Food Chem ; 139(1-4): 938-43, 2013 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-23561193


We evaluated the antioxidant, antibacterial, and anti-inflammatory activities of honey made from different floral sources, including the medicinal herb Bidens pilosa, fruit trees, Dimocarpus longan, Litchi chinensis, and Citrus maxima, the Taiwanese endemic plant Aglaia formosana, and a multifloral forest. The total phenolic and flavonoid contents of the honey made from B. pilosa were significantly higher than those of the other honeys. The honey from B. pilosa also had significantly greater scavenging activities for 1,1-diphenyl-2-picrylhydrazyl (DPPH·) and hydroxyl radical, and substantially more reducing power. In addition, the honey from B. pilosa showed greater antibacterial activity against gram-positive and gram-negative bacteria. However, B. pilosa honey showed little inhibitory activity against IL-8 secretion, whereas the other honeys did. These findings suggest that the levels of antioxidant and antibacterial activities are attributable to the total phenolic and flavonoid contents of honeys, while the IL-8 inhibition is attributable to components other than phenols.

Anti-Infecciosos/análise , Anti-Inflamatórios/análise , Antioxidantes/análise , Abelhas/metabolismo , Flores/metabolismo , Mel/análise , Animais , Anti-Infecciosos/farmacologia , Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Bactérias/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Flavonoides/análise , Flavonoides/farmacologia , Humanos , Interleucina-8/antagonistas & inibidores , Interleucina-8/imunologia , Taiwan
IEEE Trans Syst Man Cybern B Cybern ; 42(5): 1357-68, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22547457


Most face recognition scenarios assume that frontal faces or mug shots are available for enrollment to the database, faces of other poses are collected in the probe set. Given a face from the probe set, one needs to determine whether a match in the database exists. This is under the assumption that in forensic applications, most suspects have their mug shots available in the database, and face recognition aims at recognizing the suspects when their faces of various poses are captured by a surveillance camera. This paper considers a different scenario: given a face with multiple poses available, which may or may not include a mug shot, develop a method to recognize the face with poses different from those captured. That is, given two disjoint sets of poses of a face, one for enrollment and the other for recognition, this paper reports a method best for handling such cases. The proposed method includes feature extraction and classification. For feature extraction, we first cluster the poses of each subject's face in the enrollment set into a few pose classes and then decompose the appearance of the face in each pose class using Embedded Hidden Markov Model, which allows us to define a set of subject-specific and pose-priented (SSPO) facial components for each subject. For classification, an Adaboost weighting scheme is used to fuse the component classifiers with SSPO component features. The proposed method is proven to outperform other approaches, including a component-based classifier with local facial features cropped manually, in an extensive performance evaluation study.

Inteligência Artificial , Biometria/métodos , Técnicas de Apoio para a Decisão , Face/anatomia & histologia , Expressão Facial , Interpretação de Imagem Assistida por Computador/métodos , Reconhecimento Automatizado de Padrão/métodos , Algoritmos , Humanos
G3 (Bethesda) ; 2(3): 357-70, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22413090


Switchgrass (Panicum virgatum) has been identified as a promising cellulosic biofuel crop in the United States. Construction of a genetic linkage map is fundamental for switchgrass molecular breeding and the elucidation of its genetic mechanisms for economically important traits. In this study, a novel population consisting of 139 selfed progeny of a northern lowland genotype, NL 94 LYE 16X13, was used to construct a linkage map. A total of 2493 simple sequence repeat markers were screened for polymorphism. Of 506 polymorphic loci, 80.8% showed a goodness-of-fit of 1:2:1 segregation ratio. Among 469 linked loci on the framework map, 241 coupling vs. 228 repulsion phase linkages were detected that conformed to a 1:1 ratio, confirming disomic inheritance. A total of 499 loci were mapped to 18 linkage groups (LG), of which the cumulative length was 2085.2 cM, with an average marker interval of 4.2 cM. Nine homeologous LG pairs were identified based on multi-allele markers and comparative genomic analysis. Two clusters of segregation-distorted loci were identified on LG 5b and 9b, respectively. Comparative analysis indicated a one-to-one relationship between nine switchgrass homeologous groups and nine foxtail millet (Setaria italica) chromosomes, suggesting strong homology between the two species. The linkage map derived from selfing a heterozygous parent, instead of two separate maps usually constructed for a cross-fertilized species, provides a new genetic framework to facilitate genomics research, quantitative trait locus (QTL) mapping, and marker-assisted breeding.