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Problematic technology use during adolescence: why don’t teenagers seek treatment?
In recent issues of Education and Health, I have briefly reviewed the empirical evidence relating to problematic use of technology by adolescents including online video gaming (Griffiths, 2014), social networking (Griffiths, 2013a; Kuss & Griffiths, 2011), and mobile phone use (Griffiths, 2013b). Most of the research studies that have examined ‘technological addictions’ during adolescence have indicated that a small but significant minority experience severe problems resulting in detriments to education, physical fitness, psychological wellbeing, and family and personal relationships (Griffiths, 2010; Kuss, Griffiths, Karila & Billieux, 2014). Given these findings, why is it that so few teenagers seek treatment? This article briefly outlines a number of reasons why this might be the case by examining other literature on adolescent drug use and adolescent gambling (e.g., Chevalier & Griffiths, 2005; 2005; Griffiths, 2001). Three different types of explanation are discussed: (i) treatment-specific explanations, (ii) research-related explanations, and (iii) developmental and peer group explanations
Hodge metrics and positivity of direct images
Building on Fujita-Griffiths method of computing metrics on Hodge bundles, we
show that the direct image of an adjoint semi-ample line bundle by a projective
submersion has a continuous metric with Griffiths semi-positive curvature. This
shows that for every holomorphic semi-ample vector bundle on a complex
manifold, and every positive integer , the vector bundle
has a continuous metric with Griffiths semi-positive curvature. If is ample
on a projective manifold, the metric can be made smooth and Griffiths positive.Comment: revised and expanded version of "A positivity property of ample
vector bundles
Comment on "A Tale of Two Theories: Quantum Griffiths Effects in Metallic Systems" by A. H. Castro-Neto and B. A. Jones
In a recent paper Castro-Neto and Jones argue that because the observability
of quantum Griffiths-McCoy effects in metals is controlled by non-universal
quantities, the quantum Griffiths-McCoy scenario may be a viable explanation
for the non-fermi-liquid behavior observed in heavy fermion compounds. In this
Comment we point out that the important non-universal quantity is the damping
of the spin dynamics by the metallic electrons; quantum Griffiths-McCoy effects
occur only if this is parametrically weak relative to other scales in the
problem, i.e. if the spins are decoupled from the carriers. This suggests that
in heavy fermion materials, where the Kondo effect leads to a strong
carrier-spin coupling, quantum Griffiths-McCoy effects are unlikely to occur.Comment: 2 page
Quantum Locality?
Robert Griffiths has recently addressed, within the framework of a
'consistent quantum theory' that he has developed, the issue of whether, as is
often claimed, quantum mechanics entails a need for faster-than-light transfers
of information over long distances. He argues that the putative proofs of this
property that involve hidden variables include in their premises some
essentially classical-physics-type assumptions that are fundamentally
incompatible with the precepts of quantum physics. One cannot logically prove
properties of a system by establishing, instead, properties of a system
modified by adding properties alien to the original system. Hence Griffiths'
rejection of hidden-variable-based proofs is logically warranted. Griffiths
mentions the existence of a certain alternative proof that does not involve
hidden variables, and that uses only macroscopically described observable
properties. He notes that he had examined in his book proofs of this general
kind, and concluded that they provide no evidence for nonlocal influences. But
he did not examine the particular proof that he cites. An examination of that
particular proof by the method specified by his 'consistent quantum theory'
shows that the cited proof is valid within that restrictive version of quantum
theory. An added section responds to Griffiths' reply, which cites general
possibilities of ambiguities that make what is to be proved ill-defined, and
hence render the pertinent 'consistent framework' ill defined. But the vagaries
that he cites do not upset the proof in question, which, both by its physical
formulation and by explicit identification, specify the framework to be used.
Griffiths confirms the validity of the proof insofar as that framework is used.
The section also shows, in response to Griffiths' challenge, why a putative
proof of locality that he has described is flawed.Comment: This version adds a response to Griffiths' reply to my original. It
notes that Griffiths confirms the validity of my argument if one uses the
framework that I use. Griffiths' objection that other frameworks exist is not
germaine, because I use the unique one that satisfies the explicitly stated
conditions that the choices be macroscopic choices of experiments and
outcomes in a specified orde
Finite temperature behavior of strongly disordered quantum magnets coupled to a dissipative bath
We study the effect of dissipation on the infinite randomness fixed point and
the Griffiths-McCoy singularities of random transverse Ising systems in chains,
ladders and in two-dimensions. A strong disorder renormalization group scheme
is presented that allows the computation of the finite temperature behavior of
the magnetic susceptibility and the spin specific heat. In the case of Ohmic
dissipation the susceptibility displays a crossover from Griffiths-McCoy
behavior (with a continuously varying dynamical exponent) to classical Curie
behavior at some temperature . The specific heat displays Griffiths-McCoy
singularities over the whole temperature range. For super-Ohmic dissipation we
find an infinite randomness fixed point within the same universality class as
the transverse Ising system without dissipation. In this case the phase diagram
and the parameter dependence of the dynamical exponent in the Griffiths-McCoy
phase can be determined analytically.Comment: 23 pages, 12 figure
The Appointment of Dr. Jose-Marie Griffiths to the Position of Vice President for Academic Affairs
Bryant University President Ronald K. Machtley is proud to announce the appointment of Dr. Jośe-Marie Griffiths to the distinguished position of Vice President for Academic Affairs and requests that you join him in welcoming Dr. Griffiths to the Bryant University communit
On the Griffiths numbers for higher dimensional singularities
We show that Yau's conjecture on the inequalities for (n-1)-th Griffiths
number and (n-1)-th Hironaka number does not hold for isolated rigid Gorenstein
singularities of dimension greater than 2. But his conjecture on the inequality
for (n-1)-th Griffiths number is true for irregular singularities.Comment: to appear in Annales de l'Institut Fourie
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