4,816 research outputs found
Influence of Di erent Sieving Methods on Estimation of Sand Size Parameters
Sieving is one of the most used operational methods to determine sand size parameters
which are essential to analyze coastal dynamics. However, the influence of hand versus mechanical
shaking methods has not yet been studied. Herein, samples were taken from inside the hopper of
a trailing suction dredger and sieved by hand with sieves of 10 and 20 cm diameters on board the
dredger. Afterwards, these same samples were sieved with a mechanical shaker in the laboratory on
land. The results showed di erences for the main size parameters D50, standard deviation, skewness,
and kurtosis. Amongst the main results, it should be noted that the highest values for D50 and
kurtosis were given by the small sieves method. On the other hand, the lowest values were given by
the mechanical shaker method in the laboratory. Furthermore, standard deviation and skewness did
not seem to be a ected by the sieving method which means that all the grainsize distribution was
shifted but the shape remained unchanged. The few samples that do not follow these patterns have a
higher percentage of shells. Finally and definitely, the small sieves should be rejected as a sieving
method aboard
Preventing Psychological Wear in Healthy Organizations. Research in the State of Hidalgo, Mexico
Materials and methods: Non-experimental, cross-sectional quantitative study of 188 employees in different business sectors, State of Hidalgo, Mexico. Instrument: a battery for the study of psychosocial work conditions “CTCPS-MAC”. A bivariate and multivariable logistic regression analysis was made with IBM SPSS Statistics 21 of psychological wear and psychosocial factors. Results: Work Context (p=0.000 Exp (B) = 5.565) infers a greater risk of cognitive-emotional psychological wear. Behavioral level: individual factors (p=0.000 Exp (B) = 8.531) and work context (p=0.000 Exp (B) = 4.759). Physiological level: work content (p=0.000 Exp (B) = 8.765) Conclusions: Probability of psychological wear at the behavioral level: 94.87% in employees with a negative perception of their personal traits and the work/family interrelation. Physiological level: 97.70% for employees in the morning or morning/afternoon shift, good perception of individual factors regarding their personal traits and psychological risk buffers and a bad perception of company characteristics, equipment and physical agents
Outflow of hot and cold molecular gas from the obscured secondary nucleus of NGC3256: closing in on feedback physics
The nuclei of merging galaxies are often deeply buried in dense layers of gas
and dust. In these regions, gas outflows driven by starburst and AGN activity
are believed to play a crucial role in the evolution of these galaxies.
However, to fully understand this process it is essential to resolve the
morphology and kinematics of such outflows. Using near-IR integral-field
spectroscopy obtained with VLT/SINFONI, we detect a kpc-scale structure of
high-velocity molecular hydrogen (H2) gas associated with the deeply buried
secondary nucleus of the IR-luminous merger NGC3256. We show that this
structure is likely the hot component of a molecular outflow, which is detected
also in the cold molecular gas by Sakamoto et al. This outflow, with a
molecular gas mass of M(H2)~2x10^7 Msun, is among the first to be spatially
resolved in both the hot H2 gas with VLT/SINFONI and the cold CO-emitting gas
with ALMA. The hot and cold components share a similar morphology and
kinematics, with a hot-to-cold molecular gas mass ratio of ~6x10^-5. The high
(~100 pc) resolution at which we map the geometry and velocity structure of the
hot outflow reveals a biconical morphology with opening angle ~40 deg and gas
spread across a FWZI~1200 km/s. Because this collimated outflow is oriented
close to the plane of the sky, the molecular gas may reach maximum intrinsic
outflow velocities of ~1800 km/s, with an average mass outflow rate of at least
~20 Msun/yr. By modeling the line-ratios of various near-IR H2 transitions, we
show that the H2 gas in the outflow is heated through shocks or X-rays to a
temperature of ~1900K. The energy needed to drive the outflow is likely
provided by a hidden Compton-thick AGN or by the nuclear starburst. We show
that the global kinematics of the molecular outflow in NGC3256 mimic those of
CO-outflows that have been observed at low spatial resolution in starburst- and
active galaxies.Comment: Accepted in Astronomy and Astrophysics (accepted 29 Aug 2014 v.3,
initial submission v.1 14 March 2014), 13 pages, 8 figure
Development of a Social Gamified Platform for e-Learning
The way in which nowadays education is evolving, makes it possible to associate it with MOOCs courses and gamification techniques to improve learning outcomes of students. To this end, this paper shows the development of an educational e-learning platform built upon the Elgg social framework, where a set of gamification elements were added: Points, achievements, leaderboards and rewards. For the future, effectiveness validations will be carried out with students as well as further developments with other types of gamification elements
Caracterización economica del municipio de Rionegro, Antioquia, 2004-2006
Este trabajo caracteriza la actividad económica del Municipio de Rionegro (Antioquia) en el período 2004-2006. A partir del análisis de la evolución de su estructura productiva, las dinámicas recientes en los principales sectores económicos y las características de su mercado laboral; todo enmarcado en el contexto del desempeño reciente de la economía del Oriente antioqueño. El dinamismo económico de esta región ha tenido especial relevancia en el municipio de Rionegro como resultado, entre otros factores, del abastecimiento de productos agrícolas y materias primas para el Área Metropolitana del Valle de Aburrá, del acelerado desarrollo urbano y turístico, de su infraestructura vial, de servicios y, telecomunicaciones de carácter departamental y nacional y por los servicios hoteleros de alta calidad. Rionegro es considerado eje central de la subregión, por su aparato productivo y laboral que le han permitido apalancar el desarrollo socioeconómico de la zona y servir como modelo y referente en sus prácticas administrativas.Oriente Antioqueño - condiciones economicas, Rionegro (Antioquia) - aspectos economicos, Mercado laboral - Rionegro (Antioquia)
Calibration of Numerical Modelling of Hydrological and Hydraulic Processes in Arnas Experimental Basin
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
Gamifying massive online courses: effects on the social networks and course completion rates
This paper analyzes the e ects of gamification in the social network of a massive online
course. An educational social-networking platform gathered information about the contributions of participants and about the social networks that were formed during the course. A gamification layer with three game elements (points, badges, and leaderboard) was then implemented in the online learning platform. Social network analysis (SNA) and principal component analysis (PCA) were used to analyze the di erences between a treatment and a comparison group (N = 591 and N = 427), using a set of 20 variables for each participant which quantified contributions to the learning platform as well as position and influence in the social network. The results of SNA show that gamification influences the structure of the social network of the course. The results also suggest that the variables cluster similarly for each group and that the linear combination of variables called the first component (F1) is a good descriptor of students’ work and position in the network. F1 can be used to build predictive models of course completion. The models show that the probability of passing the course increases more rapidly in the treatment (gamified) group.Spanish Ministry of Economic A airs and Digital Transformation (Grant TIN2014-54874-R) and Government of Comunidad de Madrid (Grant CM/JIN/2019-037).info:eu-repo/semantics/publishedVersio
Survival Patterns of Human Prion Diseases in Spain, 1998-2018: Clinical Phenotypes and Etiological Clues
Background: Human transmissible spongiform encephalopathies (TSEs) are a group of fatal neurodegenerative disorders of short duration. There are few studies on TSE survival. This study sought to analyze the survival and related factors of a TSE patient cohort, based on a nationwide surveillance system in Spain. Methods: Survival analyses were performed on 1,530 cases diagnosed across the period 1998–2018 in Spain. We calculated median survival times and plotted survival curves using the Kaplan–Meier method for all cases and for sporadic TSE (sTSE) and genetic TSE (gTSE). Crude and adjusted Cox proportional hazard models were used to identify variables associated with shorter survival. Findings: Median age at onset decreased from the sporadic forms to gTSE and, lastly, to acquired TSE. Overall median and interquartile range (IQR) survival time was 5.2 (IQR, 3.0–11.7) months and 4.9 (IQR, 2.8–10.8) months in sporadic cases and 9 (IQR, 4.9 to over 12) months in genetic cases, p < 0.001. Male sex, older age at onset, presence of 14-3-3 protein, typical MRI, and MM and VV polymorphisms at codon 129 were associated with shorter survival. gTSE showed higher survival in crude comparisons but not after adjustment. Interpretation: TSE survival in Spain replicates both the magnitude of that shown and the TSE entity-specific population patterns observed in Western countries but differs from features described in Asian populations, such as the Japanese. The reduction in differences in survival between gTSE and sTSE on adjusting for covariates and international patterns might support the view that gTSE and sTSE share causal and pathophysiological features.This work was basically funded by the Spain’s Ministry of Health and the Carlos III Health Institute (research grant no. PI08/0139) and Consortium for Biomedical Research in Neurodegenerative Diseases (CIBERNED) networks (QLRG3-CT-2002-81223). Role of funders: The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.S
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