3,198 research outputs found
Lorentz and CPT Violation in the Higgs Sector
Colladay and Kostelecky have proposed a framework for studying Lorentz and
CPT violation in a natural extension of the Standard Model. Although numerous
bounds exist on the Lorentz and CPT violating parameters in the gauge boson and
fermion sectors, there are no published bounds on the parameters in the Higgs
sector. We determine these bounds. The bounds on the CPT-even asymmetric
coefficients arise from the one-loop contributions to the photon propagator,
those from the CPT-even symmetric coefficients arise from the equivalent
c_{\mu\nu} coefficients in the fermion sector, and those from the CPT-odd
coefficient arise from bounds on the vacuum expectation value of the Z-boson.Comment: 17 pages, 1 figure, 1 table; Clarifications and changes to text,
results unchanged. References added. Version to be published in Physical
Review
InN dielectric function from the midinfrared to the visible range
The dispersion of the dielectric function for wurtzite InN is analytically
evaluated in the region near the fundamental energy gap. The real part of the
dielectric function has a logarithmic singularity at the absorption edge. This
results in the large contribution into the optical dielectric constant. For
samples with degenerate carriers, the real part of the dielectric function is
divergent at the absorption edge. The divergence is smeared with temperatures
or relaxation rate. The imaginary part of the dielectric function has a plateau
far away from the absorption onset.Comment: 5 pages, 2 figure
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A critical analysis of COA research.
Five experts respected for their significant contributions to the scientific literature on children of alcoholics (COA's) offer their perspectives in a panel discussion format. The panel members reflect on the historical roots of COA research and comment on its current status and future direction. Enriched by the panelists' variety of backgrounds, research interests, and approaches, the discussion emphasizes the need to consider multiple variables that influence the risk for alcoholism among COA's
Type I interferons in tuberculosis: Foe and occasionally friend
Tuberculosis remains one of the leading causes of mortality worldwide, and, despite its clinical significance, there are still significant gaps in our understanding of pathogenic and protective mechanisms triggered by Mycobacterium tuberculosis infection. Type I interferons (IFN) regulate a broad family of genes that either stimulate or inhibit immune function, having both host-protective and detrimental effects, and exhibit well-characterized antiviral activity. Transcriptional studies have uncovered a potential deleterious role for type I IFN in active tuberculosis. Since then, additional studies in human tuberculosis and experimental mouse models of M. tuberculosis infection support the concept that type I IFN promotes both bacterial expansion and disease pathogenesis. More recently, studies in a different setting have suggested a putative protective role for type I IFN. In this study, we discuss the mechanistic and contextual factors that determine the detrimental versus beneficial outcomes of type I IFN induction during M. tuberculosis infection, from human disease to experimental mouse models of tuberculosis
Electromagnetic and Gravitational Radiation of Graviatoms
Graviatom existence conditions have been found. The graviatoms (quantum
systems around mini-black-holes) satisfying these conditions contain the
following charged particles: the electron, muon, tau lepton, wino, pion and
kaon. Electric dipole and quadrupole and gravitational radiations are
calculated for the graviatoms and compared with Hawking's mini-hole radiation.Comment: 7 pages, 1 figure, 3 tables; accepted in "Astronomical and
Astrophysical Transactions
Surgical technique of orthotopic liver transplantation
Athough significant strides have been made in the surgical technique of orthotopic liver transplantation, numerous problems and nuisances are still encountered. Further surgical refinements will certainly evolve. The development of better preservation techniques, the use of intraoperative flowmeters, and the availability of new technologies, such as an artificial liver, should impact and advance the techniques of liver transplantation significantly and improve the overall results even further
Obstructing mucocele of the cystic duct after transplantation of the liver
A tension mucocele was created in three hepatic homografts by ligating a low-lying cystic duct during transplant cholecystectomy and by incorporating its outflow end into the anastomosis of the common hepatic duct to the recipient common duct or Roux limb of jejunum. The consequent complication of obstruction of the biliary tract that necessitated reoperation and excision of the mucocele in all three patients can be avoided by the simple expedient of completely removing the cystic duct when feasible or providing egress to the secretion of the cystic duct as described
Rule behind the silk curtain: the Sultanahs of Aceh 1641-1699.
PhDThis thesis is about the kingdom of Aceh Dar al-Salam in the latter half of the
seventeenth century when four women ruled in succession: Sultanah Tajul Alam
Safiatuddin Syah (1641-1675), Sultanah Nur Alam Naqiatuddin Syah (1675-1678),
Sultanah Inayat Zakiatuddin Syah (1678-1688) and Sultanah Iamalat Zainatuddin Syah
(1688-1699). How and why these queens came to power, and how they exercised it, are
problems that have fascinated enquirers, prompting a range of comments and
observations, especially the assertion that the queens were mere figureheads, during
whose reigns the male elite (orangkaya) captured power. The Sultanahs were held
responsible for the erosion of royal power and the kingdom's decline in the seventeenth
century. Yet no in-depth study has ever investigated these claims. The main objective of
this thesis is to evaluate the received views on these female sovereigns. The thesis also
seeks to examine the origin, nature and impact of these Sultanahs. Female rule seems a
curious phenomenon in a Muslim state. Furthermore, in a largely patriarchal kingdom
such as Aceh, queens seemed to be strangely out of place. This unique episode in Aceh's
history happened when European Companies - the Dutch VOC (Veerinigde Ooost-Indische
Compagnie) and the English East India Company - were gradually increasing their
commercial hold and flexing their military muscles in the region. Indigenous polities
suffered increasing interference and pressure from Westerners. Most Malay and Muslim
coastal polities in maritime Southeast Asia fell into European intruders' hands. By
exploring the circumstances and arguments surrounding female accession, and
examining some key episodes that show how power worked in Aceh at the time, I hope
to approach a new understanding of how and why the male elite of Aceh placed the fate
of the kingdom in the hands of women, and with what effects
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