2,387 research outputs found
Well-posedness and asymptotic behavior of a multidimensional model of morphogen transport
Morphogen transport is a biological process, occurring in the tissue of
living organisms, which is a determining step in cell differentiation. We
present rigorous analysis of a simple model of this process, which is a system
coupling parabolic PDE with ODE. We prove existence and uniqueness of solutions
for both stationary and evolution problems. Moreover we show that the solution
converges exponentially to the equilibrium in topology. We
prove all results for arbitrary dimension of the domain. Our results improve
significantly previously known results for the same model in the case of one
dimensional domain
Medical Device Innovation in Massachusetts -- M2D2: Massachusetts Medical Device Development Center
This presentation describes the role of the medical device industry in the economy of Massachusetts and how the Massachusetts Medical Device Development (M2D2) Center can assist entrepreneurs and new companies working in this space
Playing with Casimir in the vacuum sandbox
The Casimir effect continues to be a subject of discussion regarding its
relationship, or the lack of it, with the vacuum energy of fluctuating quantum
fields. In this note, we propose a Gedankenexperiment considering an imaginary
process similar to a vacuum fluctuation in a typical static Casimir set up. The
thought experiment leads to intriguing conclusions regarding the minimum
distance between the plates when approaching the Planck scale. More
specifically, it is found that distance between the plates cannot reach a value
below Planck lengths, being the Planck length and the
typical lateral extension of the plates. Additional findings allow the
conclusion that the approach between the two plates towards this minimum
separation distance is asymptotic
Searching for galactic sources in the Swift GRB catalog
Since the early 1990s Gamma Ray Bursts have been accepted to be of
extra-galactic origin due to the isotropic distribution observed by BATSE and
the redshifts observed via absorption line spectroscopy. Nevertheless, upon
further examination at least one case turned out to be of galactic origin. This
particular event presented a Fast Rise, Exponential Decay (FRED) structure
which leads us to believe that other FRED sources might also be Galactic. This
study was set out to estimate the most probable degree of contamination by
galactic sources that certain samples of FREDs have. In order to quantify the
degree of anisotropy the average dipolar and quadripolar moments of each sample
of GRBs with respect to the galactic plane were calculated. This was then
compared to the probability distribution of simulated samples comprised of a
combination of isotropically generated sources and galactic sources. We observe
that the dipolar and quadripolar moments of the selected subsamples of FREDs
are found more than two standard deviations outside those of random
isotropically generated samples.The most probable degree of contamination by
galactic sources for the FRED GRBs of the Swift catalog detected until February
2011 that do not have a known redshift is about 21 out of 77 sources which is
roughly equal to 27%. Furthermore we observe, that by removing from this sample
those bursts that may have any type of indirect redshift indicator and multiple
peaks gives the most probable contamination increases up to 34% (17 out of 49
sources). It is probable that a high degree of contamination by galactic
sources occurs among the single peak FREDs observed by Swift.Comment: Published to A&A, 4 pages, 5 figures, this arXiv version includes
appended table with all the bursts considered in this stud
Extrinsic and intrinsic effects setting viscosity in life processes: implications for fundamental physical constants
Understanding the values and origin of fundamental physical constants, one of
the grandest challenges in modern science, has been discussed in particle
physics, astronomy and cosmology. More recently, it was realised that
fundamental constants have a bio-friendly window set by life processes
involving motion and flow. This window is related to intrinsic fluid properties
such as energy and length scales in condensed matter set by fundamental
constants. Here, we discuss important extrinsic factors governing the viscosity
of complex fluids operating in life processes due to collective effects. We
show that both extrinsic and intrinsic factors affecting viscosity need to be
taken into account when estimating the bio-friendly range of fundamental
constants from life processes, and our discussion provides a straightforward
recipe for doing this. We also find that the relative role of extrinsic and
intrinsic factors depends on the range of variability of these intrinsic and
extrinsic factors. Remarkably, the viscosity of a complex fluid such as blood
with significant extrinsic effects is not far from the intrinsic viscosity
calculated using the fundamental constants only, and we discuss the reason for
this in terms of dynamics of contact points between cells.Comment: arXiv admin note: text overlap with arXiv:2307.0527
Knowledge and degree of training of Primary Education teachers in relation to ICT taught to disabled students
The integration of Information and Communication Technologies (ICT) into the inclusive classroom requires competent teaching staff from both the technological and pedagogical points of view. Within this context, and with the aim of looking at one of these theoretical premises, this study aimed to identify the degree of training and technological knowledge of primary school teachers in Spain with respect to the use of ICT with individuals with disabilities (functional diversity). A descriptive ex post-facto research method was used, where the sample comprised 777 teachers. An ad-hoc questionnaire was used as the data-collection instrument. The results revealed the low skill levels of the teachers with respect to the use of ICT with students with disabilities, where the level of training of the teaching staff was determined by personal (gender, age), professional (teaching experience) or educational (qualifications) variables. The findings of this study point to the need for teacher training that instructs teachers on the use of ICT in order to favour the learning and educational innovation of students with disabilities
The metadata catalogue of the Spanish Institute of Oceanography: a tool to implement the EU Marine Strategy Framework Directive (MSFD)
The Spanish Institute of Oceanography (IEO-CSIC) is responsible, among other aspects, for scientific and technical advice for the Government's fisheries policy as well as for the protection and sustainability of the marine environment. Thus, the IEO-CSIC plays a key role in the implementation of the Marine Strategy Framework Directive (MSFD), an EU legislative act that seeks to achieve a good environmental status of European marine waters and protect the resource base on which sustain economic and social activities related to the sea. Under this commission, the IEO-CSIC generates a large amount of marine data characterized by its spatial dispersion during acquisition as well as by its different typology. One of the main tasks is to safeguard data and to disclose what data exists and where, how and when it has been acquired and, in addition, to provide access to that data through the collaboration with different national and international organizations. To this end, the data and metadata are subjected to quality control and formatted for integration into a national Spatial Data Infrastructure (SDI). This SDI has a GeoNetwork catalogue (http://datos.ieo.es) with ~ 2800 oceanographic campaigns. The metadata of the campaigns known as Cruise Summary Report (CSR) follow the ISO 19139, and although similar to those reported to the pan European SeaDataNet infrastructure, here they have been adapted following an XSL transformation to facilitate the data discovery to the Spanish community. CSRs constitute the parent metadata for ~ 250 layers associated with the implementation of the MSFD. Thus, the INSPIRE-compliant layers with biological, geological and physical resource data can be found through the catalogue and are linked to the corresponding map services. Finally, relevant metadata for the implementation of the MSFD are harvested in other national infrastructures, as the InfoMar catalogue (http://www.infomar.miteco.es/), promoted by the Ministry for the Ecological Transition and the Demographic Challenge and maintained by the CEDEX
Development of a work climate scale in emergency health services
An adequate work climate fosters productivity in organizations and increases employee satisfaction. Workers in emergency health services (EHS) have an extremely high degree of responsibility and consequent stress. Therefore, it is essential to foster a good work climate in this context. Despite this, scales with a full study of their psychometric properties (i.e., validity evidence based on test content, internal structure and relations to other variables, and reliability) are not available to measure work climate in EHS specifically. For this reason, our objective was to develop a scale tomeasure the quality of work climates in EHS.We carried out three studies. In Study 1, we used a mixed-method approach to identify the latent conceptual structure of the construct work climate. Thus, we integrated the results found in (a) a previous study, where a content analysis of seven in-depth interviews obtained from EHS professionals in two hospitals in Gibraltar Countryside County was carried out; and (b) the factor analysis of the responses given by 113 EHS professionals from these same centers to 18 items that measured the work climate in health organizations. As a result, we obtained 56 items grouped into four factors (work satisfaction, productivity/achievement of aims, interpersonal relationships, and performance at work). In Study 2, we presented validity evidence based on test content through experts’ judgment. Fourteen experts from the methodology and health fields evaluated the representativeness, utility, and feasibility of each of the 56 items with respect to their factor (theoretical dimension). Forty items met the inclusion criterion, which was to obtain an Osterlind index value greater than or equal to 0.5 in the three aspects assessed. In Study 3, 201 EHS professionals from the same centers completed the resulting 40-item scale. This new instrument produced validity evidence based on the internal structure in a second-order factormodel with four components (RMSEA=0.079,
GFI = 0.97, AGFI = 0.97, CFI = 0.97; NFI = 0.95, and NNFI = 0.97); absence of differential Item Functioning (DIF) in 80% of the items; reliability (a = 0.96); and validity evidence based on relations to other variables, specifically the test-criterion relationship (r = 0.680). Finally, we discuss further developments of the instrument and its possible implications for EHS workers.Ministerio de Ciencia e Innovación PSI2011-29587Ministerio de Economía y Competitividad PSI2015-71947-RED
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