1,721,367 research outputs found
Fotografía UDBC019480
No full textFotografía del ejemplar Velasco, L. 385, determinado como Miconia ligustrina en el año 200
Fotografía UDBC019555
No full textFotografía del ejemplar Velasco, L. 376, determinado como Gaultheria anastomosans en el año 200
Fotografía UDBC019589
No full textFotografía del ejemplar Velasco, L. 378, determinado como Myrsine dependens en el año 200
Fotografía UDBC019463
No full textFotografía del ejemplar Velasco-L., P. 382, determinado como Galium hypocarpium en el año 200
Nondestructive assessment of protein content in single seeds of rapeseed (Brassica napus L.) by near-infrared reflectance spectroscopy
No full textThe potential of near-infrared reflectance spectroscopy (NIRS) to detect within-plant differences for seed protein content was investigated. Four hundred and fifty-one single seeds were scanned by NIRS using a special adapter. After non-destructive NIRS scanning, the seeds were analysed for protein content by the Dumas combustion method and a calibration equation was developed. A validation set of 117 additional seeds from three individual plants from the cultivars Bristol, Lirajet and Maplus was analysed for protein content both by NIRS and combustion. The coefficient of determination between NIRS and combustion values in the validation set was 0.94, with a standard error of performance (SEP) of 0.77% and a ratio of the SEP to the standard deviation (SD) of the validation set of 0.28. The coefficient of variation (CV) for seed protein content in individual plants. as determined by the combustion method, was 11.7% for Bristol, 8.9% for Lirajet, and 9.5% for Maplus. The comparison of such variation with the standard error (SE) of NIRS analysis, defined as the combination of the SE of the combustion method and the SEP of NIRS calibration equation, revealed that the maximum explainable variance within individual plants that can be detected using NIRS analysis of protein content in single seeds was 0.86 for Bristol, 0.83 for Lirajet, and 0.85 for Maplus. These results demonstrated that NIRS is a powerful tool for non-destructive assessment of within-plant variation for seed protein content in rapeseed
Use of near-infrared reflectance spectroscopy to assess nitrogen concentration in different plant tissues of rapeseed
No full textAn evaluation of the performance of near-infrared reflectance spectroscopy (NIRS) in the analysis of nitrogen (N) concentration in different rapeseed (Brassica napus L.) tissues was made. A total of 228 samples from an N-efficiency study corresponding to leaves and stems at flowering, fallen leaves, mature stems, and mature pod walls were oven dried, ground, and then analyzed by NIRS. The N concentration was determined by Dumas combustion. Two different calibration strategies were followed: (i) separate calibration equations were developed for each type of tissue, resulting in r(2) above 0.95 in crossvalidation for all tissues with the ratio of the standard error of crossvalidation (SECV) to the standard deviation of the population (SD) ranging from 0.10 to 0.22, and (ii) a NIRS calibration equation was developed from a set integrating 149 samples from the five groups of tissues. External validation with a set containing 79 further samples from all the groups resulted in an r(2) of 0.99 and a ratio of the standard error of performance (SEP) to the SD of 0.08. External validation for each group separately resulted in r(2) from 0.91 to 0.99 and SEP/SD from 0.10 to 0.27. It was concluded that a universal NIPS calibration equation integrating samples from all the types of tissues is an adequate approach for the accurate analysis of N concentration in rapeseed. Based on our results, the NIPS technique can reliably replace the Kjeldahl or Dumas methods to determine the N concentration in investigations of the N efficiency in rapeseed
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
- …
