662 research outputs found
Cuscuton: A Causal Field Theory with an Infinite Speed of Sound
We introduce a model of scalar field dark energy, Cuscuton, which can be
realized as the incompressible (or infinite speed of sound) limit of a scalar
field theory with a non-canonical kinetic term (or k-essence). Even though
perturbations of Cuscuton propagate superluminally, we show that they have a
locally degenerate phase space volume (or zero entropy), implying that they
cannot carry any microscopic information, and thus the theory is causal. Even
coupling to ordinary scalar fields cannot lead to superluminal signal
propagation. Furthermore, we show that the family of constant field
hypersurfaces are the family of Constant Mean Curvature (CMC) hypersurfaces,
which are the analogs of soap films (or soap bubbles) in a Euclidian space.
This enables us to find the most general solution in 1+1 dimensions, whose
properties motivate conjectures for global degeneracy of the phase space in
higher dimensions. Finally, we show that the Cuscuton action can model the
continuum limit of the evolution of a field with discrete degrees of freedom
and argue why it is protected against quantum corrections at low energies.
While this paper mainly focuses on interesting features of Cuscuton in a
Minkowski spacetime, a companion paper (astro-ph/0702002) examines cosmology
with Cuscuton dark energy.Comment: 11 pages, 1 figure, added discussion of "coupled cuscuton", matches
the published version in PR
Total order in opportunistic networks
Opportunistic network applications are usually assumed to work only with unordered immutable messages, like photos, videos, or music files, while applications that depend on ordered or mutable messages, like chat or shared contents editing applications, are ignored. In this paper, we examine how total ordering can be achieved in an opportunistic network. By leveraging on existing dissemination and causal order algorithms, we propose a commutative replicated data type algorithm on the basis of Logoot for achieving total order without using tombstones in opportunistic networks where message delivery is not guaranteed by the routing layer. Our algorithm is designed to use the nature of the opportunistic network to reduce the metadata size compared to the original Logoot, and even to achieve in some cases higher hit rates compared to the dissemination algorithms when no order is enforced. Finally, we present the results of the experiments for the new algorithm by using an opportunistic network emulator, mobility traces, and Wikipedia pages.Peer ReviewedPostprint (author's final draft
INGA 3D - creative transfer of competence in 3D footwear CAD to VET professionals
INGA 3D project - Creative Transfer of Competence in 3D Footwear CAD to VET Professionals aims to transfer and extend innovative software solutions and 3D technologies for Footwear Computer Aided Design. The project brings together universities, research and training centres, adult education providers and IT companies from Romania, Spain, Portugal, and UK. The project products introduce innovative solutions for e-learning in order to test and to validate new teaching methodologies and approaches suitable for vocational training. The INGA 3D training content, its supportive guide as well as the online learning platform was designed, developed, tested and evaluated in line with the best practices identified by partners in their institutions, countries and elsewhere in Europe. INGA 3D project contributes to developing skills and competencies of VET teachers, trainers, tutors, in order to face the future challenges raised by the necessity of adding to the current curricula in VET institutions ICT skill sets that will enable their graduates to work with highly specialized footwear CAD technologies
Applications of Hilbert Module Approach to Multivariable Operator Theory
A commuting -tuple of bounded linear operators on a
Hilbert space \clh associate a Hilbert module over
in the following sense: where and
. A companion survey provides an introduction to the theory
of Hilbert modules and some (Hilbert) module point of view to multivariable
operator theory. The purpose of this survey is to emphasize algebraic and
geometric aspects of Hilbert module approach to operator theory and to survey
several applications of the theory of Hilbert modules in multivariable operator
theory. The topics which are studied include: generalized canonical models and
Cowen-Douglas class, dilations and factorization of reproducing kernel Hilbert
spaces, a class of simple submodules and quotient modules of the Hardy modules
over polydisc, commutant lifting theorem, similarity and free Hilbert modules,
left invertible multipliers, inner resolutions, essentially normal Hilbert
modules, localizations of free resolutions and rigidity phenomenon.
This article is a companion paper to "An Introduction to Hilbert Module
Approach to Multivariable Operator Theory".Comment: 46 pages. This is a companion paper to arXiv:1308.6103. To appear in
Handbook of Operator Theory, Springe
Operator theory and function theory in Drury-Arveson space and its quotients
The Drury-Arveson space , also known as symmetric Fock space or the
-shift space, is a Hilbert function space that has a natural -tuple of
operators acting on it, which gives it the structure of a Hilbert module. This
survey aims to introduce the Drury-Arveson space, to give a panoramic view of
the main operator theoretic and function theoretic aspects of this space, and
to describe the universal role that it plays in multivariable operator theory
and in Pick interpolation theory.Comment: Final version (to appear in Handbook of Operator Theory); 42 page
A QUALITATIVE APPROACH OF THE ASSOCIATION BETWEEN THE TODDLER’S ATTACHMENT STYLE AND THE DYADIC INTERACTION WITH THE MOTHER
The quality of toddler’s experience with the caregiver impacts the structuring of the internal working models of attachment (Bowlby, 1980, 1988), further used as means of comfort and security, and prototypes for later close relationships. Using inductive qualitative techniques, our study aims to describe specific schemes of mother-toddler interaction, for each of the attachment styles. Semi-structured interactions of 27 mother-child dyads were videotaped in their familiar environment and the films were qualitatively analyzed, for each group of toddlers previously identified as having the same attachment style. The interactions of secure toddlers and their mothers were marked by synchronized actions, joy of interacting, closeness, and security. Mothers of ambivalent children displayed a more dominant action, with discordances between the social and psychological level of communication. Avoidant toddler-mother dyads presented a higher balance between their relational spaces, maintaining contact, with a low level of intimacy. The absence of a coherent strategy defined the interaction between the toddlers with disorganized attachment and their mothers. Our results confirm previous findings in the field of attachment in early childhood and add up to these results by providing a methodology to approach these interactions and the use of video recordings as ways to develop interventions aiming to increase the attachment security.
ZUSAMMENFASSUNG. Die Qualität der Interaktion von Kleinkindern mit ihren Bezugspersonen wirkt auf die Strukturierung der inneren Arbeitsmodelle (Bowlby, 1980, 1988) ein. Diese Arbeitsmodelle werden als Mittel in der Suche nach Trost und Sicherheit und als Prototypen für spätere enge Beziehungen benutzt. Unsere Studie nimmt sich vor, Mutter-Kleinkind-Interaktionen für jeden Bindungstyp durch induktive qualitative Techniken zu beschreiben. Dazu wurden die halbstrukturierten Interaktionen von 27 Mutter-Kind Zweiergruppen in ihrem gewohnten Umgebung auf Video aufgezeichnet. Danach wurden die Aufnahmen für jede Gruppe von Kleinkindern, die zuvor die gleiche Bindungsart aufgewiesen hatten, einer qualitativen Analyse unterzogen. Die Interaktionen zwischen sicher gebundenen Kindern und ihren Müttern sind von synchronisierten Handlungen, Freude an Interaktion, Nähe und Sicherheit geprägt. Die Mütter von ambivalent gebundenen Kindern zeigen sich dominanter in ihren Handlungen, wobei auch Widesprüche zwischen der sozialen und psychologischen Kommunikationsebene zu beobachten sind. Das Gleichgewicht zwischen den Bindungsräumen von vermeidenden Kindern und ihren Müttern war besser, sie halten Kontakt, jedoch mit kleinem Vertrautheitsgrad. Die Interaktion zwischen desorganisiert gebundenen Kleinkindern und ihren Müttern wies den Mangel an einer kohärenten Strategie vor. Unsere Ergebnisse bestätigen vorausgegangene Untersuchungen über frühkindliche Bindung und ergänzen diese durch die Erstellung einer Analysemethode dieser Interaktionen und durch die Verwendung von Videoaufnahmen als Entwicklungsmöglichkeit für Interventionen zur Verbesserung der Bindungssicherheit der Kinder.
Schlüsselwörter: Mutter-Kleinkind-Interaktion; Bindungstypen; Videoanalyse; qualitative Untersuchun
The employee as 'Dish of the Day’:human resource management and the ethics of consumption
This article examines the ethical implications of the growing integration of consumption into the heart of the employment relationship. Human resource management (HRM) practices increasingly draw upon the values and practices of consumption, constructing employees as the ‘consumers’ of ‘cafeteria-style’ benefits and development opportunities. However, at the same time employees are expected to market themselves as items to be consumed on a corporate menu. In relation to this simultaneous position of consumer/consumed, the employee is expected to actively engage in the commodification of themselves, performing an appropriate organizational identity as a necessary part of being a successful employee. This article argues that the relationship between HRM and the simultaneously consuming/consumed employee affects the conditions of possibility for ethical relations within organizational life. It is argued that the underlying ‘ethos’ for the integration of consumption values into HRM practices encourages a self-reflecting, self-absorbed subject, drawing upon a narrow view of individualised autonomy and choice. Referring to Levinas’ perspective that the primary ethical relation is that of responsibility and openness to the Other, it is concluded that these HRM practices affect the possibility for ethical being
Establishing What Constitutes a Healthy Human Gut Microbiome: State of the Science, Regulatory Considerations, and Future Directions.
On December 17, 2018, the North American branch of the International Life Sciences Institute (ILSI North America) convened a workshop "Can We Begin to Define a Healthy Gut Microbiome Through Quantifiable Characteristics?" with >40 invited academic, government, and industry experts in Washington, DC. The workshop objectives were to 1) develop a collective expert assessment of the state of the evidence on the human gut microbiome and associated human health benefits, 2) see if there was sufficient evidence to establish measurable gut microbiome characteristics that could serve as indicators of "health," 3) identify short- and long-term research needs to fully characterize healthy gut microbiome-host relationships, and 4) publish the findings. Conclusions were as follows: 1) mechanistic links of specific changes in gut microbiome structure with function or markers of human health are not yet established; 2) it is not established if dysbiosis is a cause, consequence, or both of changes in human gut epithelial function and disease; 3) microbiome communities are highly individualized, show a high degree of interindividual variation to perturbation, and tend to be stable over years; 4) the complexity of microbiome-host interactions requires a comprehensive, multidisciplinary research agenda to elucidate relationships between gut microbiome and host health; 5) biomarkers and/or surrogate indicators of host function and pathogenic processes based on the microbiome need to be determined and validated, along with normal ranges, using approaches similar to those used to establish biomarkers and/or surrogate indicators based on host metabolic phenotypes; 6) future studies measuring responses to an exposure or intervention need to combine validated microbiome-related biomarkers and/or surrogate indicators with multiomics characterization of the microbiome; and 7) because static genetic sampling misses important short- and long-term microbiome-related dynamic changes to host health, future studies must be powered to account for inter- and intraindividual variation and should use repeated measures within individuals
THE STUDY OF ACCLIMATIZATION OF GRAPES OF MEDITERRANEAN ORIGIN TO THE WEATHER CONDITIONS OF THE WINE-GROWING REGIONS OF SEGARCEA
This study was carried out during 2019-2020 on plots belonging to the wine-growing areas of Segarcea, famous wine areas in point of extracting red wine with remarkable qualities in the south of the country. The significance of the work consists in improving the useful climate of the wi ne area of Segarcea by introducing into the culture beside black grapes varieties, renowned varieties like Feteascăneagră, Merlot, Cabernet-Sauvignon, Pinot noir, etc., other grape varieties of Mediteranean origin, such as Syrah and Marselan. The aim is to rigorously monitor the weather conditions with a direct impact on the soils with a production potential, observing the dynamics of its establishment and maturation index for each variety during the period studied
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