64 research outputs found
Algebraic approach to quantum field theory on non-globally-hyperbolic spacetimes
The mathematical formalism for linear quantum field theory on curved
spacetime depends in an essential way on the assumption of global
hyperbolicity. Physically, what lie at the foundation of any formalism for
quantization in curved spacetime are the canonical commutation relations,
imposed on the field operators evaluated at a global Cauchy surface. In the
algebraic formulation of linear quantum field theory, the canonical commutation
relations are restated in terms of a well-defined symplectic structure on the
space of smooth solutions, and the local field algebra is constructed as the
Weyl algebra associated to this symplectic vector space. When spacetime is not
globally hyperbolic, e.g. when it contains naked singularities or closed
timelike curves, a global Cauchy surface does not exist, and there is no
obvious way to formulate the canonical commutation relations, hence no obvious
way to construct the field algebra. In a paper submitted elsewhere, we report
on a generalization of the algebraic framework for quantum field theory to
arbitrary topological spaces which do not necessarily have a spacetime metric
defined on them at the outset. Taking this generalization as a starting point,
in this paper we give a prescription for constructing the field algebra of a
(massless or massive) Klein-Gordon field on an arbitrary background spacetime.
When spacetime is globally hyperbolic, the theory defined by our construction
coincides with the ordinary Klein-Gordon field theory on aComment: 21 pages, UCSBTH-92-4
UPAYA GURU PAI DALAM MENGATASI PENYIMPANGAN PERILAKU ANAK TUNAGRAHITA DI SLB C YPLB DANYANG KABUPATEN GROBOGAN TAHUN AJARAN 2017/2018
Tujuan dalam penelitian ini adalah untuk mengetahui apa saja bentuk
penyimpangan perilaku yang dilakukan anak tunagrahita di SLB C YPLB
Danyang Purwodadi Kabupaten Grobogan. Tujuan selanjutnya yaitu bagaimana
upaya yang dilakukan guru pendidikan Agama Islam dalam mengatasi
penyimpangan perilaku anak tunagrahita tersebut. Selain itu peneliti juga ingin
mengetahui apa saja faktor penghambat dalam melaksanakan upaya mengatasi
penyimpangan perilaku anak tunagrahita di SLB C YPLB Danyang Purwodadi
Kabupaten Grobogan Tahun Ajaran 2017/2018.
Penelitian ini menggunakan metode kualitatif deskriptif lapangan.
Penelitian ini dilaksanakan di SLB C YPLB Danyang Purwodadi Kabupaten
Grobogan bulan April sampai dengan November 2017. Subjek penelitiannya
adalah Guru Pendidikan Agama Islam. Sedangkan informannya adalah Kepala
Sekolah dan siswa. Tehnik pengumpulan data yang peneliti gunakan dengan
metode observasi, wawancara dan dokumentasi. Untuk mengetahui keabsahan
data menggunakan tehnik triangulasi sumber dan triangulasi metode. Tehnik
analisis data dalam penelitian ini yaitu 1) data reduction (reduksi data), 2) data
display (penyajian data), 3) drawing conclusion/ verification (penarikan
kesimpulan/verifikasi).
Hasil penelitian ini berdasarkan yang telah diuraikan pada bab-bab
sebelumnya, maka dapat diambil kesimpulan bahwa bentuk-bentuk penyimpangan
perilaku yang dilakukan anak tunagrahita antara lain: 1) tindakan anti sosial 2)
tindakan yang tidak sesuai dengan norma di masyarakat 3) tindakan kriminal.
Sedangkan upaya yang dilakukan guru pendidikan agama Islam dalam hal
mengatasi penyimpangan perilaku anak tunagrahita yaitu 1) konseling
individual/pribadi. 2) metode pembiasaan yang dilaksanakan pada saat di dalam
kelas maupun di luar kelas. 3) home visit. Adapun faktor penghambat dalam
melaksanakan upaya tersebut yaitu 1) pola perilaku yang tidak sesuai dengan
kemampuannya 2) ketidakmampuan dalam mengadaptasikan dirinya terhadap
lingkungan 3) adanya masalah kesehatan yang khusus seperti tingkat pertumbuhan
yang tidak normal 4) kelainan penyerta celebral palsy
The averaged null energy condition and difference inequalities in quantum field theory
Recently, Larry Ford and Tom Roman have discovered that in a flat cylindrical
space, although the stress-energy tensor itself fails to satisfy the averaged
null energy condition (ANEC) along the (non-achronal) null geodesics, when the
``Casimir-vacuum" contribution is subtracted from the stress-energy the
resulting tensor does satisfy the ANEC inequality. Ford and Roman name this
class of constraints on the quantum stress-energy tensor ``difference
inequalities." Here I give a proof of the difference inequality for a minimally
coupled massless scalar field in an arbitrary two-dimensional spacetime, using
the same techniques as those we relied on to prove ANEC in an earlier paper
with Robert Wald. I begin with an overview of averaged energy conditions in
quantum field theory.Comment: 20 page
Signaling, Entanglement, and Quantum Evolution Beyond Cauchy Horizons
Consider a bipartite entangled system half of which falls through the event
horizon of an evaporating black hole, while the other half remains coherently
accessible to experiments in the exterior region. Beyond complete evaporation,
the evolution of the quantum state past the Cauchy horizon cannot remain
unitary, raising the questions: How can this evolution be described as a
quantum map, and how is causality preserved? What are the possible effects of
such nonstandard quantum evolution maps on the behavior of the entangled
laboratory partner? More generally, the laws of quantum evolution under extreme
conditions in remote regions (not just in evaporating black-hole interiors, but
possibly near other naked singularities and regions of extreme spacetime
structure) remain untested by observation, and might conceivably be non-unitary
or even nonlinear, raising the same questions about the evolution of entangled
states. The answers to these questions are subtle, and are linked in unexpected
ways to the fundamental laws of quantum mechanics. We show that terrestrial
experiments can be designed to probe and constrain exactly how the laws of
quantum evolution might be altered, either by black-hole evaporation, or by
other extreme processes in remote regions possibly governed by unknown physics.Comment: Combined, revised, and expanded version of quant-ph/0312160 and
hep-th/0402060; 13 pages, RevTeX, 2 eps figure
Studi Kematian Ibu dan Kematian Bayi di Provinsi Sumatera Barat: Faktor Determinan dan Masalahnya
One of the main goals that WHO wants to reach in 2000 is Health for All Year 2000. Some of indicators have been using to measure the goals, such as infant mortality rate (IMR) and maternal mortality rate (MMR). West Sumatera Health Office had been successed reducing IMR and MMR for over 5 years, but the score was not mentioned the exact number becausethis measurement just using national statistic measurement. It also could not describe the disparity between the area and sosial group in West Sumatera. This research aim is to get the exact number of IMR and MMR, determinat factors and its problems in West Sumatera in 2007. The study desain was Direct Household Survey Method with prospective approach. The research was done in 19 different government district in West Sumatera from January 1st until December 31st 2007. Result of this research found IMR and MMR of West Sumatera in 2007 is 28,4 per 1.000 birth life and 211,9 per 100.000 birth life. Asphyxia and postpartum bleeding is the main cause of infant and maternal death. West Sumatera Health Office and its government should have a strong commitment to build effective networking to reduce IMR and MMR in West Sumatera
Mutations in GABRB3
Objective: To examine the role of mutations in GABRB3 encoding the b3 subunit of the GABAA receptor in individual patients with epilepsy with regard to causality, the spectrum of genetic variants, their pathophysiology, and associated phenotypes. Methods: We performed massive parallel sequencing of GABRB3 in 416 patients with a range of epileptic encephalopathies and childhood-onset epilepsies and recruited additional patients with epilepsy with GABRB3 mutations from other research and diagnostic programs. Results: We identified 22 patients with heterozygous mutations in GABRB3, including 3 probands frommultiplex families. The phenotypic spectrum of the mutation carriers ranged from simple febrile seizures, genetic epilepsies with febrile seizures plus, and epilepsy withmyoclonic-atonic seizures to West syndrome and other types of severe, early-onset epileptic encephalopathies. Electrophysiologic analysis of 7 mutations in Xenopus laevis oocytes, using coexpression of wild-type or mutant beta(3), together with alpha(5) and gamma(2s) subunits and an automated 2-microelectrode voltage-clamp system, revealed reduced GABA-induced current amplitudes or GABA sensitivity for 5 of 7 mutations. Conclusions: Our results indicate that GABRB3 mutations are associated with a broad phenotypic spectrum of epilepsies and that reduced receptor function causing GABAergic disinhibition represents the relevant disease mechanism
The effect of local corticosteroid injection on F-wave conduction velocity and sympathetic skin response in carpal tunnel syndrome
The aim of this study was to evaluate the efficacy of steroid injection for the treatment of the carpal tunnel syndrome (CTS), with F-wave parameters and sympathetic skin response (SSR). Seventeen hands of 10 women patients were treated with local steroid injection with 2-month follow-up. All patients underwent single injection into the carpal tunnel. Response to injection was measured nerve conduction studies (NCSs), median nerve F waves, and SSR before and after treatment. To determine the normal values, 42 hands of 21 healthy women were also studied. There was a significant improvement of sensory and motor nerve conduction values when compared to baseline values (P < 0.01). At the end of follow-up period, the median sensory distal latency and the sensory latency differences between the median and the ulnar nerve were improved 35 and 65%, respectively. The maximum, mean F-wave amplitudes and chronodispersion showed a slight improvement with respect to baseline values and controls, but statistical significance was not achieved after treatment. Although no statistically significant improvements were observed in SSR parameters, slightly decreased amplitudes and increased habituation of SSR were noted at the end of the treatment. The present study shows that the local steroid injection results in improvement in NCSs values, but the F-wave parameters were not effectual in short-term outcome of CTS treatment. These findings suggest that the sensory latency differences between the median and the ulnar wrist-to-digit 4 are better parameters in the median nerve recovery after treatment than the median sensory distal latency. Furthermore, the SSR does not seem to be a sensitive method in follow-up of CTS treatment
Understanding the roles of gingival beta-defensins
Gingival epithelium produces β-defensins, small cationic peptides, as part of its contribution to the innate host defense against the bacterial challenge that is constantly present in the oral cavity. Besides their functions in healthy gingival tissues, β-defensins are involved in the initiation and progression, as well as restriction of periodontal tissue destruction, by acting as antimicrobial, chemotactic, and anti-inflammatory agents. In this article, we review the common knowledge about β-defensins, coming from in vivo and in vitro monolayer studies, and present new aspects, based on the experience on three-dimensional organotypic culture models, to the important role of gingival β-defensins in homeostasis of the periodontium
Coccidian Infection Causes Oxidative Damage in Greenfinches
The main tenet of immunoecology is that individual variation in immune responsiveness is caused by the costs of immune responses to the hosts. Oxidative damage resulting from the excessive production of reactive oxygen species during immune response is hypothesized to form one of such costs. We tested this hypothesis in experimental coccidian infection model in greenfinches Carduelis chloris. Administration of isosporan coccidians to experimental birds did not affect indices of antioxidant protection (TAC and OXY), plasma triglyceride and carotenoid levels or body mass, indicating that pathological consequences of infection were generally mild. Infected birds had on average 8% higher levels of plasma malondialdehyde (MDA, a toxic end-product of lipid peroxidation) than un-infected birds. The birds that had highest MDA levels subsequent to experimental infection experienced the highest decrease in infection intensity. This observation is consistent with the idea that oxidative stress is a causative agent in the control of coccidiosis and supports the concept of oxidative costs of immune responses and parasite resistance. The finding that oxidative damage accompanies even the mild infection with a common parasite highlights the relevance of oxidative stress biology for the immunoecological research
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