2,282 research outputs found
A geometric basis for the standard-model gauge group
A geometric approach to the standard model in terms of the Clifford algebra
Cl_7 is advanced. A key feature of the model is its use of an algebraic spinor
for one generation of leptons and quarks. Spinor transformations separate into
left-sided ("exterior") and right-sided ("interior") types. By definition,
Poincare transformations are exterior ones. We consider all rotations in the
seven-dimensional space that (1) conserve the spacetime components of the
particle and antiparticle currents and (2) do not couple the right-chiral
neutrino. These rotations comprise additional exterior transformations that
commute with the Poincare group and form the group SU(2)_L, interior ones that
constitute SU(3)_C, and a unique group of coupled double-sided rotations with
U(1)_Y symmetry. The spinor mediates a physical coupling of Poincare and
isotopic symmetries within the restrictions of the Coleman--Mandula theorem.
The four extra spacelike dimensions in the model form a basis for the Higgs
isodoublet field, whose symmetry requires the chirality of SU(2). The charge
assignments of both the fundamental fermions and the Higgs boson are produced
exactly.Comment: 17 pages, LaTeX requires iopart. Accepted for publication in J. Phys.
A: Math. Gen. 9 Mar 2001. Typos correcte
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Regulatory incentives and financial reporting quality in public healthcare organisations
English National Health Service Foundation Trusts are subject to a regulatory regime in which the level of monitoring and intervention is determined by performance against two key performance metrics: a âfinancial risk ratingâ, based on a number of performance metrics, such as the reported surplus margin and return on assets, and a âprudential borrowing limitâ. In this paper, we investigate the variation in financial reporting quality, proxied by discretionary accruals, with the incentives introduced by this regime. We find: first, that discretionary accruals are managed to report small surpluses; second, that, consistent with the avoidance of regulatory intervention in both the short and medium term, discretionary accruals are more positive when pre-managed performance is below intervention triggering thresholds and more negative when well above threshold; third, that, despite a move away from financial breakeven as the primary performance objective, there remains an aversion to small loss reporting. We further find that the level of discretionary accruals is driven by two metrics of strategic significance: the surplus margin (a measure of retained earnings) and the prudential borrowing limit (a measure of borrowing capacity)
Failure to induce mutations in Neurospora with amino acid analogs
Failure to induce mutations with amino acid analog
The U.S.-UK âSpecial Military Relationshipâ: Resetting the Partnership
The article of record as published may be found at https://doi.org/10.1080/01495933.2012.665722Although the âspecial relationshipâ between U.S. and British officials is a fixture of the international scene, recent events have raised concerns about the nature and strength of the partnership. This article explores the issues that animate the dialogue between Washington and London and describes insights gathered from a recent Anglo-American forum held in the United Kingdom. Both countries have shared interests in Afghanistan, Libya, and in the nuclear and intelligence fields more generally. Nevertheless, a chang- ing geopolitical setting, especially increasing U.S. preoccupation with China and the declining British defense budget, suggests that sustaining the special relationship will become more difficult
Actidione resistance: a forward mutation technique and its application for mosaic analysis
Actidione resistance: a forward mutation technique and its application for mosaic analysi
Notes on the use of microconidiating strains in mutation experiments
Notes on the use of micrconidiating strains in mutation experiment
Estimation of the frequency of multinucleate conidia in microconidiating strains
Frequency of multinucleate conidia in microconidiating strain
Male gender predisposes to development of endotoxic shock in the rat
Objective: After intravenous (i.v.) injection of lipopolysaccharide (LPS) macrophages release nitric oxide (NO) due to the expression of the inducible NO synthase (iNOS). After LPS NO is abundantly produced also in the cardiovascular system and may contribute to the development of hypotension and shock. Since the immune response, the synthesis of NO and the regulation of blood pressure (BP) differ between males and females, in the present study the effect of LPS on BP, renal function, the plasma and urinary concentration of the metabolites of NO as well as the splenic and aortic expression of the iNOS gene were compared between male and female rats. Methods: BP and renal function were measured in anesthetized rats following the i.v. injection of LPS (E. coli, 4 mg/kg). The NOx and NOx (metabolites of NO=NOx) concentration was measured by the Griess reaction. The iNOS gene expression was studied by RT-PCR. Results: Four hours after LPS, BP of males (n=9) was reduced by 63+/-12 mmHg versus 10+/-4 in females (n=7, P<0.005). Aminoguanidine, a selective inhibitor of iNOS, prevented the reduction of BP in males. The plasma concentration of NOx (P-NOx, mu M) was lower in hypotensive males (128+/-20) than in normotensive females (235+/-29, P<0.005). Males also exhibited lower urinary NO, excretion (UNOxV) after LPS (P<0.001 vs, females). Prior castration of males provided protection against hypotension (fall of BP: -4+/-4 mmHg, n=6, P<0.02 versus males) and resulted in higher P-NOx as well as UNOxV (both P<0.001 versus males and not different from females). Prior ovariectomy (n=5) had no influence on the hemodynamic and NOx response to LPS. Male rats displayed enhanced aortic iNOS/beta-actin ratio relative to females after LPS (n=3 in each group, P<0.05). Conclusions: (1) Male gender may sensitize to LPS-induced shock and (2) sensitivity of males to endotoxin is associated with an attenuated, not exaggerated total rate of NO synthesis
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