Search results for "SAMPLE"
showing 10 items of 2270 documents
Analysis of Social Media Impact on Opportunity Recognition. A Social Networks and Entrepreneurial Alertness Mixed Approach
2020
This paper investigates the effects of social media on entrepreneurial opportunity recognition. Combining the internal and external approaches of opportunity recognition, the study analyzes how social media influences the entrepreneurs in discovering new entrepreneurial opportunities. Structural equation modeling was used in this study, using the variance-based partial least squares (PLS)&ndash
Comparative environmental analysis of soil sampling methods in precision agriculture for lime application in Paraná State, Brazil
2020
Precision agriculture (PA) provides techniques that favour the localized application of inputs allowing their rational use. This makes the PA a potential indicator of reduced operational costs, input volume, and environmental impacts. The objective of this study was to evaluate and compare the environmental effects of three different sampling methods used in PA for the lime application. The first sampling method evaluated was the grid sampling (GS). It was performed at a density of one sample per hectare in a 100×100 m georeferenced grid. The second method was the directed sampling, that was performed after defining the management zones by soil apparent electrical conductivity (ECa) using a…
Metodología innovadora en la universidad: sus efectos sobre los procesos de aprendizaje de los estudiantes universitarios
2015
Se pretendía evaluar el impacto de metodología centrada en el aprendizaje sobre las estrategias de aprendizaje y los enfoques de aprendizaje de un grupo de alumnos de Química, de 1º curso de Ingeniería, de la Universitat Politécnica de Valencia. Se utilizó un diseño preexperimental, con medidas de pretest y postest, tomadas mediante el cuestionario CEVEAPEU y el CPE. La muestra estaba constituida por 20 alumnos. Los métodos docentes utilizados integraban metodología expositiva, preguntas, resolución de problemas, elaboración de una monografía, exposiciones orales, prácticas de laboratorio, trabajo en grupo, tutorías en el aula y un sistema de evaluación que hacía uso de procedimientos forma…
Longitudinal associations between adolescent behaviour problems and perceived family relationships
2010
AbstractThe goal of the present study was to examine the longitudinal associations between perceived family relationships and adolescents’ externalizing/ internalizing problems. The study sample included 366 pupils from secondary schools in Latvia, 12-14 years of age, who completed self-report questionnaires. Data were collected in two assessments 1 year apart. The results indicate that elevations in adolescent problem behavior prospectively predicted subsequent decreases in perceived family cohesion and increases in family conflict. The effect of perceived family cohesion and conflict as assessed at Time1 was not statistically significant in prediction of Time2 adolescent behaviour problem…
Hopes and Fears for the Future Among Chinese Adolescents
2014
This study examined the contents of adolescents' hopes and fears for the future in a sample of 1,975 urban and rural 8th, 10th, and 12th graders in China. Chinese adolescents' hopes and fears were most often related to future education, occupation, parental well-being, marriage and family, academics, leisure activities, wealth, interpersonal relationships, collective issues, and self-related issues. Urban adolescents compared to rural ones reported more hopes for education and leisure activities and held fewer hopes and fears for parental well-being and interpersonal relationships. Males reported more hopes and fears for marriage, whereas females reported more hopes and fears for parental w…
Machine learning for mortality analysis in patients with COVID-19
2020
This paper analyzes a sample of patients hospitalized with COVID-19 in the region of Madrid (Spain). Survival analysis, logistic regression, and machine learning techniques (both supervised and unsupervised) are applied to carry out the analysis where the endpoint variable is the reason for hospital discharge (home or deceased). The different methods applied show the importance of variables such as age, O2 saturation at Emergency Rooms (ER), and whether the patient comes from a nursing home. In addition, biclustering is used to globally analyze the patient-drug dataset, extracting segments of patients. We highlight the validity of the classifiers developed to predict the mortality, reaching…
Italian Consumers’ Preferences for Pasta and Consumption Trends: Tradition or Innovation?
2019
The aim of this study is to know Italian consumers’ preferences for Pasta and consumption habits. Food culture and concerns about food security and product innovation were investigated. A sample of Italian consumers was interviewed. Consumer’ profile, motivations and purchasing behavior were described. Relationships between observed variables and the latent constructs that explain the preferences were highlighted. There is asymmetric information between consumers and producers. Consumers believe Pasta is made with Italian grains, and therefore it is healthy and safe, although that’s not always the case. Intrinsic and extrinsic high quality, which derives from growing and production technolo…
Different sample treatment approaches for the analysis of T-2 and HT-2 toxins from oats-based media.
2010
A LC-DAD method is proposed for the determination of the T-2 and HT-2 toxins in cultures of Fusarium langsethiae in oat-based and other in vitro media. Test media consisted of freshly prepared milled oats to which T-2 and HT-2 toxin stock solutions were added. Different mixtures of extraction solvent (acetonitrile:water and methanol water), extraction times (30', 60' or 90') and drying methods were investigated. Results showed that extraction with methanol: water (80:20, v/v) for 90 min, drying with N-2 and subsequent analysis by LC-DAD was the fastest and most user friendly method for detecting HT-2 and T-2 toxins production by F. langsethiae strains grown on oat-based media at levels of 0…
Validation and application of a PCR primer set to quantify fungal communities in the soil environment by real-time quantitative PCR
2011
Fungi constitute an important group in soil biological diversity and functioning. However, characterization and knowledge of fungal communities is hampered because few primer sets are available to quantify fungal abundance by real-time quantitative PCR (real-time Q-PCR). The aim in this study was to quantify fungal abundance in soils by incorporating, into a real-time Q-PCR using the SYBRGreen (R) method, a primer set already used to study the genetic structure of soil fungal communities. To satisfy the real-time Q-PCR requirements to enhance the accuracy and reproducibility of the detection technique, this study focused on the 18S rRNA gene conserved regions. These regions are little affec…
Unveiling the environment and faint features of the isolated galaxy CIG 96 with deep optical and HI observations
2018
Context. Asymmetries in atomic hydrogen (HI) in galaxies are often caused by the interaction with close companions, making isolated galaxies an ideal framework to study secular evolution. The AMIGA project has demonstrated that isolated galaxies show the lowest level of asymmetry in their HI integrated profiles compared to even field galaxies, yet some present significant asymmetries. CIG 96 (NGC 864) is a representative case reaching a 16% level. Aims. Our aim is to investigate the HI asymmetries of the spiral galaxy CIG 96 and what processes have triggered the star-forming regions observed in the XUV pseudo-ring. Methods. We performed deep optical observations at CAHA1.23m, CAHA2.2m and V…