2,815 research outputs found
Level structures on the Weierstrass family of cubics
Let W -> A^2 be the universal Weierstrass family of cubic curves over C. For
each N >= 2, we construct surfaces parametrizing the three standard kinds of
level N structures on the smooth fibers of W. We then complete these surfaces
to finite covers of A^2. Since W -> A^2 is the versal deformation space of a
cusp singularity, these surfaces convey information about the level structure
on any family of curves of genus g degenerating to a cuspidal curve. Our goal
in this note is to determine for which values of N these surfaces are smooth
over (0,0). From a topological perspective, the results determine the
homeomorphism type of certain branched covers of S^3 with monodromy in
SL_2(Z/N).Comment: LaTeX, 12 pages; added section giving a topological interpretation of
the result
Density dependent strong coupling constant of QCD derived from compact star data
The present work is an endeavour to connect the properties of tiny nearly
massless objects with those of some of the most massive ones, the compact
stars.
Since 1996 there is major influx of X-ray and ray data from binary
stars, one or both of which are compact objects that are difficult to explain
as neutron stars since they contain a mass M in too small a radius R . The
suggestion has been put forward that these are strange quark stars (SS)
explainable in a simple model with chiral symmetry restoration (CSR) for the
quarks and the M, R and other properties like QPOs (quasi periodic
oscillations) in their X-ray power spectrum.
It would be nice if this astrophysical data could shed some light on
fundamental properties of quarks obeying QCD. One can relate the strong
coupling constant of QCD, to the quark mass through the
Dyson-Schwinger gap equation using the real time formalism of Dolan and Jackiw.
This enables us to obtain the density dependence of from the simple
CSR referred to above. This way fundamental physics, difficult to extract from
other models like for example lattice QCD, can be constrained from present-day
compact star data and may be put back to modelling the dense quark phase of
early universe.Comment: 7 pages, 4 figure
Examining the Impact of Treatment Fidelity on Client Outcomes in a Statewide Implementation of Parent-Child Interaction Therapy
Clinician treatment fidelity, consisting of treatment adherence and clinician competence, is commonly assessed during the implementation of evidence-based treatments to ensure that clinicians are delivering care according to an intended service model. Although resources are often expended in fidelity measurement, associations between fidelity and client outcomes has not been well established in the psychotherapy literature. The relationship between clinician fidelity and treatment outcomes was investigated in a longitudinal sample of clinicians (n = 17) and parent-child dyads (n = 32) following a statewide implementation of Parent-Child Interaction Therapy. Observer-rated measures of adherence and coaching competence collected from early treatment sessions were used to predict intake levels and growth trajectories of parent-reported behavior problems and positive parenting skills. Hierarchical linear modeling results indicated that higher levels of coaching competence were associated with greater behavior problem frequency at intake. Neither early session adherence nor early session competence, as they were measured in the current study, predicted changes in treatment outcomes over time. These results suggest that additional variables should be modeled alongside early treatment fidelity to predict treatment outcome change. Possible explanations for these findings, limitations of the current study, and directions for future research are discussed
Mechanisms for Outsourcing Computation via a Decentralized Market
As the number of personal computing and IoT devices grows rapidly, so does
the amount of computational power that is available at the edge. Since many of
these devices are often idle, there is a vast amount of computational power
that is currently untapped, and which could be used for outsourcing
computation. Existing solutions for harnessing this power, such as volunteer
computing (e.g., BOINC), are centralized platforms in which a single
organization or company can control participation and pricing. By contrast, an
open market of computational resources, where resource owners and resource
users trade directly with each other, could lead to greater participation and
more competitive pricing. To provide an open market, we introduce MODiCuM, a
decentralized system for outsourcing computation. MODiCuM deters participants
from misbehaving-which is a key problem in decentralized systems-by resolving
disputes via dedicated mediators and by imposing enforceable fines. However,
unlike other decentralized outsourcing solutions, MODiCuM minimizes
computational overhead since it does not require global trust in mediation
results. We provide analytical results proving that MODiCuM can deter
misbehavior, and we evaluate the overhead of MODiCuM using experimental results
based on an implementation of our platform
Holomorphic selection rules, the origin of the mu term, and thermal inflation
When an abelian gauge theory with integer charges is spontaneously broken by
the expectation value of a charge Q field, there remains a Z_Q discrete
symmetry. In a supersymmetric theory, holomorphy adds additional constraints on
the operators that can appear in the effective superpotential. As a result,
operators with the same mass dimension but opposite sign charges can have very
different coupling strengths. In the present work we characterize the operator
hierarchies in the effective theory due to holomorphy, and show that there
exist simple relationships between the size of an operator and its mass
dimension and charge. Using such holomorphy-induced operator hierarchies, we
construct a simple model with a naturally small supersymmetric mu term. This
model also provides a concrete realization of late-time thermal inflation,
which has the ability to solve the gravitino and moduli problems of weak-scale
supersymmetry.Comment: 18 pages, 1 figur
The combustion mitigation of methane as a non-CO2 greenhouse gas
These research results have received funding from the EU H2020 Programme (No. 689772) and from MCTI/RNP-Brazil under the HPC4E Project, grant agreement no 689772
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Qualified Person Learning Programme Development: An Example of the Tempus Joint Project Activity
The role of Qualified Person (QP) is a pivotal one in Quality Assurance within the pharmaceutical industry. The competences required are usually achieved through work experience and more formal forms of learning, such as postgraduate MSc and/or relevant short-term courses. Duties of QP in the pharmaceutical sector in Serbia used to be performed by expert pharmacists with the relevant industrial experience and a Postgraduate Specialization Degree in Drug Analysis and Quality Control. However, it has been recognized that the learning needs of QPs should be extended to
include knowledge of drug formulation and manufacturing processes. Taking into account the pre-accession status of Serbia, harmonization with EU practice and policies has been emphasized. In particular, compliance with EU directives 2001/82/EC and 2001/83/EC, which detail the role of, and academic qualifications required by a QP will be necessary. In order to respond to this need which has been highlighted within the sector, the Faculty of Pharmacy, University of Belgrade took responsibility for establishing the relevant postgraduate course, and set this as one of the priorities of the current Tempus PQPharm Project. The aim of this work is to provide an example of an outcomes-based interactive approach to curriculum development performed through an international joint-project collaboration activity
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