Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
PLoS Comput Biol ; 18(7): e1010164, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35862309

RESUMEN

Conferences are spaces to meet and network within and across academic and technical fields, learn about new advances, and share our work. They can help define career paths and create long-lasting collaborations and opportunities. However, these opportunities are not equal for all. This article introduces 10 simple rules to host an inclusive conference based on the authors' recent experience organizing the 2021 edition of the useR! statistical computing conference, which attracted a broad range of participants from academia, industry, government, and the nonprofit sector. Coming from different backgrounds, career stages, and even continents, we embraced the challenge of organizing a high-quality virtual conference in the context of the Coronavirus Disease 2019 (COVID-19) pandemic and making it a kind, inclusive, and accessible experience for as many people as possible. The rules result from our lessons learned before, during, and after the organization of the conference. They have been written mainly for potential organizers and selection committees of conferences and contain multiple practical tips to help a variety of events become more accessible and inclusive. We see this as a starting point for conversations and efforts towards building more inclusive conferences across the world. * Translated versions of the English abstract and the list of rules are available in 10 languages in S1 Text: Arabic, French, German, Italian, Japanese, Korean, Portuguese, Spanish, Tamil, and Thai.


Asunto(s)
COVID-19 , COVID-19/epidemiología , Humanos , India , Italia , Pandemias , Escritura
2.
Spectrochim Acta A Mol Biomol Spectrosc ; 267(Pt 1): 120508, 2022 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-34740006

RESUMEN

Spectroscopic techniques are commonly used for the non-invasive characterization of the molecular and elemental composition of greenstone archaeological artifacts. The surface topography of these artifacts is greatly influenced by the crafting and polishing techniques employed in their making. However, no study of the effect of roughness on spectra has ever been reported for greenstones. Here we show that infrared, Raman and X-ray fluorescence spectra are strongly influenced by the sample's surface roughness. Spectral changes were seen in both geological (45 jadeite and green stone samples) and archaeological artifacts (12 axe-God pendants); in every case, the variations were more prominent in samples with higher arithmetic average height values. The results show that these changes can affect the interpretation of the spectroscopic data and limit the efficacy of statistical analysis. Consequently, any spectroscopic characterization of this type of samples should be performed preferably in areas with lower values of roughness parameters. Overall, FT-IR appears to be the most advantageous technique to distinguish the differences in mineral composition of this type of samples during in situ studies; its performance was evaluated with an innovative statistical analysis that treats the spectra as functional data. Additionally, the results suggest that confocal Raman spectroscopy is an ideal complementary technique that enhances mineralogical characterization, nevertheless its applicability is limited to laboratory settings.


Asunto(s)
Arqueología , Espectrometría Raman , Artefactos , Minerales , Espectroscopía Infrarroja por Transformada de Fourier
3.
PLoS One ; 16(2): e0237288, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33571212

RESUMEN

Many small parasitoid wasps have a black head, an orange mesosoma and a black metasoma (BOB color pattern), which is usually present in both sexes. A likely function of this widespread pattern is aposematic (warning) coloration, but this has never been investigated. To test this hypothesis, we presented spider predators (Lyssomanes jemineus), both field-captured and bred in captivity from eggs, to four wasp genera (Baryconus, Chromoteleia, Macroteleia and Scelio), each genus being represented by a BOB morphospecies and black morphospecies. We also used false prey, consisting of lures made of painted rice grains. Behavioral responses were analyzed with respect to presence or absence of the BOB pattern. In order to better understand the results obtained, two additional studies were performed. First, the reflection spectrum of the cuticle of the wasp and a theoretical visual sensibility of the spider were used to calculate a parameter we called "absorption contrast" that allows comparing the perception contrast between black and orange in each wasp genus as viewed by the spider. Second, acute toxicity trials with the water flea, Daphnia magna, were performed to determine toxicity differences between BOB and non-BOB wasps. At least some of the results suggest that the BOB color pattern may possibly play an aposematic role.


Asunto(s)
Mimetismo Biológico/genética , Conducta Predatoria/fisiología , Pigmentación de la Piel/fisiología , Animales , Mimetismo Biológico/fisiología , Color , Femenino , Insectos , Masculino , Pigmentación/fisiología , Arañas/fisiología , Avispas/fisiología
4.
Food Chem ; 314: 125959, 2020 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-31991283

RESUMEN

Anthocyanins from purple-fleshed sweetpotatoes constitute highly valued natural colorants and functional ingredients. In the past, anthocyanin extraction conditions and efficiencies using a single acidified solvent have been assessed. However, the potential of solvent mixes that can be generated by fermentation of biomass-derived sugars have not been explored. In this study, the effects of single and mixed solvent, time, temperature, sweetpotato genotype and preparation, on anthocyanin and phenolic extraction were evaluated. Results indicated that unconventional diluted solvent mixes containing acetone, butanol, and ethanol were superior or equally efficient for extracting anthocyanins when compared to commonly used concentrated extractants. In addition, analysis of anthocyanidins concentrations including cyanidin (cy), peonidin (pe), and pelargonidin (pl), indicated that different ratios of pn/cy were obtained depending on the solvent used. These results could be useful when selecting processing conditions that better suit particular end-use applications and more environmentally friendly process development for purple sweetpotatoes.


Asunto(s)
Antocianinas/aislamiento & purificación , Fraccionamiento Químico/métodos , Ipomoea batatas/química , Solventes/química , Acetona/química , Antocianinas/análisis , Antocianinas/química , Butanoles/química , Etanol/química , Fenoles/aislamiento & purificación , Extractos Vegetales/química
5.
PLoS One ; 14(10): e0218061, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31647807

RESUMEN

Small parasitoid wasps are abundant and extremely diverse, yet their colors have not been analyzed. One of the more common color patterns observed in these wasps is a black-orange-black pattern, which is especially common among neotropical species of Scelionidae ranging in size from 2 to 10 mm. Due to the methodological challenges involved in extracting and analyzing pigments from small-sized insects, other methods for examining colors need to be explored. In this work, we propose the use of microspectrophotometry in combination with statistical analysis methods in order to 8 study the spectral properties in such cases. We examined 8 scelionid genera and 1 genus from a distantly related family (Evaniidae), all showing the black-orange-black pattern. Functional Data Analysis and statistical analysis of Euclidean distances for color components were applied to study color differences both between and within genera. The Functional Data Analysis proved to be a better method for treating the reflectance data because it gave a better representation of the physical information. Also, the reflectance spectra were separated into spectral color component contributions and each component was labeled according to its own dominant wavelength at the maximum of the spectrum: Red, Green and Blue. When comparing spectral components curves, the spectral blue components of the orange and black colors, independent of the genera being compared, result almost identical, suggesting that there is a common compound for the pigments. The results also suggest that cuticle from different genera, but with the same color might have a similar chemical composition. This is the first time that the black and orange colors in small parasitoid wasps has been analyzed and our results provide a basis for future research on the color patterns of an abundant but neglected group of insects.


Asunto(s)
Color , Pigmentación/fisiología , Pigmentos Biológicos/análisis , Análisis Espectral/métodos , Avispas/fisiología , Algoritmos , Animales , Modelos Biológicos
6.
PLoS One ; 12(1): e0169576, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28099449

RESUMEN

INTRODUCTION AND OBJECTIVES: Accelerometry is used as an objective measure of physical activity in humans and veterinary species. In cats, one important use of accelerometry is in the study of therapeutics designed to treat degenerative joint disease (DJD) associated pain, where it serves as the most widely applied objective outcome measure. These analyses have commonly used summary measures, calculating the mean activity per-minute over days and comparing between treatment periods. While this technique has been effective, information about the pattern of activity in cats is lost. In this study, functional data analysis was applied to activity data from client-owned cats with (n = 83) and without (n = 15) DJD. Functional data analysis retains information about the pattern of activity over the 24-hour day, providing insight into activity over time. We hypothesized that 1) cats without DJD would have higher activity counts and intensity of activity than cats with DJD; 2) that activity counts and intensity of activity in cats with DJD would be inversely correlated with total radiographic DJD burden and total orthopedic pain score; and 3) that activity counts and intensity would have a different pattern on weekends versus weekdays. RESULTS AND CONCLUSIONS: Results showed marked inter-cat variability in activity. Cats exhibited a bimodal pattern of activity with a sharp peak in the morning and broader peak in the evening. Results further showed that this pattern was different on weekends than weekdays, with the morning peak being shifted to the right (later). Cats with DJD showed different patterns of activity from cats without DJD, though activity and intensity were not always lower; instead both the peaks and troughs of activity were less extreme than those of the cats without DJD. Functional data analysis provides insight into the pattern of activity in cats, and an alternative method for analyzing accelerometry data that incorporates fluctuations in activity across the day.


Asunto(s)
Enfermedades de los Gatos/fisiopatología , Actividad Motora/fisiología , Osteoartritis/veterinaria , Acelerometría , Animales , Gatos , Femenino , Masculino , Osteoartritis/fisiopatología
7.
AJR Am J Roentgenol ; 203(4): 838-45, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25247950

RESUMEN

OBJECTIVE: The objective of this study was to compare the image quality of a dual-energy nonlinear image blending technique at reduced load of contrast medium with a simulated 120-kVp linear blending technique at a full dose during portal venous phase MDCT of the abdomen. SUBJECTS AND METHODS: Forty-five patients (25 men, 20 women; mean age, 65.6 ± 9.7 [SD] years; mean body weight, 74.9 ± 12.4 kg) underwent contrast-enhanced single-phase dual-energy CT of the abdomen by a random assignment to one of three different contrast medium (iomeprol 400) dose injection protocols: 1.3, 1.0, or 0.65 mL/kg of body weight. The contrast-to-noise ratio (CNR) and noise at the portal vein, liver, aorta, and kidney were compared among the different datasets using the ANOVA. Three readers qualitatively assessed all datasets in a blinded and independent fashion. RESULTS: Nonlinear blended images at a 25% reduced dose allowed a significant improvement in CNR (p < 0.05 for all comparisons), compared with simulated 120-kVp linear blended images at a full dose. No statistically significant difference existed in CNR and noise between the nonlinear blended images at a 50% reduced dose and the simulated 120-kVp linear blended images at a full dose. Nonlinear blended images at a 50% reduced dose were considered in all cases to have acceptable image quality. CONCLUSION: The dual-energy nonlinear image blending technique allows reducing the dose of contrast medium up to 50% during portal venous phase imaging of the abdomen while preserving image quality.


Asunto(s)
Neoplasias Abdominales/diagnóstico por imagen , Yopamidol/análogos & derivados , Tomografía Computarizada Multidetector/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Radiografía Abdominal/métodos , Imagen Radiográfica por Emisión de Doble Fotón/métodos , Adulto , Anciano , Anciano de 80 o más Años , Algoritmos , Medios de Contraste/administración & dosificación , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Yopamidol/administración & dosificación , Masculino , Persona de Mediana Edad , Dinámicas no Lineales , Intensificación de Imagen Radiográfica/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Técnica de Sustracción
8.
Radiology ; 273(3): 813-20, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25162309

RESUMEN

PURPOSE: To investigate whether dual-energy multidetector row computed tomographic (CT) imaging with iodine quantification is able to distinguish between clear cell and papillary renal cell carcinoma ( RCC renal cell carcinoma ) subtypes. MATERIALS AND METHODS: In this retrospective, HIPAA-compliant, institutional review board-approved study, 88 patients (57 men, 31 women) with diagnosis of either clear cell or papillary RCC renal cell carcinoma at pathologic analysis, who underwent contrast material-enhanced dual-energy nephrographic phase study between December 2007 and June 2013, were included. Five readers, blinded to pathologic diagnosis, independently evaluated all cases by determining the lesion iodine concentration on color-coded iodine maps. The receiving operating characteristic curve analysis was adopted to estimate the optimal threshold for discriminating between clear cell and papillary RCC renal cell carcinoma , and results were validated by using a leave-one-out cross-validation. Interobserver agreement was assessed by using an intraclass correlation coefficient. The correlation between tumor iodine concentration and tumor grade was investigated. RESULTS: A tumor iodine concentration of 0.9 mg/mL represented the optimal threshold to discriminate between clear cell and papillary RCC renal cell carcinoma , and it yielded the following: sensitivity, 98.2% (987 of 1005 [95% confidence interval: 97.7%, 98.7%]); specificity, 86.3% (272 of 315 [95% confidence interval: 85.0%, 87.7%]); positive predictive value, 95.8% (987 of 1030 [95% confidence interval: 95.0%, 96.6%]); negative predictive value, 93.7% (272 of 290 [95% confidence interval: 92.8%, 94.7%]); overall accuracy of 95.3% (1259 of 1320 [95% confidence interval: 94.6%, 96.2%]), with an area under the curve of 0.923 (95% confidence interval: 0.913, 0.933). An excellent agreement was found among the five readers in measured tumor iodine concentration (intraclass correlation coefficient, 0.9990 [95% confidence interval: 0. 9987, 0.9993). A significant correlation was found between tumor iodine concentration and tumor grade for both clear cell (τ = 0.85; P < .001) and papillary RCC renal cell carcinoma (τ = 0.53; P < .001). CONCLUSION: Dual-energy multidetector CT with iodine quantification can be used to distinguish between clear cell and papillary RCC renal cell carcinoma , and it provides insights regarding the tumor grade.


Asunto(s)
Carcinoma Papilar/diagnóstico por imagen , Carcinoma de Células Renales/diagnóstico por imagen , Neoplasias Renales/diagnóstico por imagen , Tomografía Computarizada Multidetector , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma Papilar/patología , Carcinoma Papilar/cirugía , Carcinoma de Células Renales/patología , Carcinoma de Células Renales/cirugía , Medios de Contraste , Diagnóstico Diferencial , Femenino , Humanos , Yopamidol/análogos & derivados , Neoplasias Renales/patología , Neoplasias Renales/cirugía , Masculino , Persona de Mediana Edad , Nefrectomía , Estudios Retrospectivos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...