49,596 research outputs found
Born-Infeld Lagrangian using Cayley-Dickson algebras
We rewrite the Born-Infeld Lagrangian, which is originally given by the
determinant of a matrix composed of the metric tensor and the
field strength tensor , using the determinant of a matrix . If the elements of
are given by the linear combination of and , it is found, based on the
representation matrix for the multiplication operator of the Cayley-Dickson
algebras, that is distinguished by a single parameter,
where distinguished matrices are not similar matrices. We also give a
reasonable condition to fix the paramet
Dispatches from the interface of salivary bioscience and neonatal research.
The emergence of the interdisciplinary field of salivary bioscience has created opportunity for neonatal researchers to measure multiple components of biological systems non-invasively in oral fluids. The implications are profound and potentially high impact. From a single oral fluid specimen, information can be obtained about a vast array of biological systems (e.g., endocrine, immune, autonomic nervous system) and the genetic polymorphisms related to individual differences in their function. The purpose of this review is to describe the state of the art for investigators interested in integrating these unique measurement tools into the current and next generation of research on gonadal steroid exposure during the prenatal and neonatal developmental periods
Observables of the generalized 2D Yang-Mills theories on arbitrary surfaces: a path integral approach
Using the path integral method, we calculate the partition function and the
generating functional (of the field strengths) of the generalized 2D Yang-Mills
theories in the Schwinger--Fock gauge. Our calculation is done for arbitrary 2D
orientable, and also nonorientable surfaces.Comment: 6 pages, LaTe
D-instantons probing D3-branes and the AdS/CFT correspondence
D-instantons are considered as a probe of coinciding D3-branes. They can
feel an external metric via the commutator terms in their effective action. We
show that when the D-instantons are separated from the D3-branes, the metric
which is probed at the one loop level, {\it exactly} coincides with that of the
BPS R-R 3-brane. Interesting connection of this result to the possible
explanation of the AdS/CFT correspondence within IKKT M-atrix theory is
discussed.Comment: 8pp., Latex. Minor changes, misprints are correcte
The knowledge-based software assistant
Where the Knowledge Based Software Assistant (KBSA) is now, four years after the initial report, is discussed. Also described is what the Rome Air Development Center expects at the end of the first contract iteration. What the second and third contract iterations will look like are characterized
A matrix ATP requirement for presequence translocation across the inner membrane of mitochondria
What do we need for robust and quantitative health impact assessment?
Health impact assessment (HIA) aims to make the health consequences of decisions explicit. Decision-makers need to know that the conclusions of HIA are robust. Quantified estimates of potential health impacts may be more influential but there are a number of concerns. First, not everything that can be quantified is important. Second, not everything that is being quantified at present should be, if this cannot be done robustly. Finally, not everything that is important can be quantified; rigorous qualitative HIA will still be needed for a thorough assessment. This paper presents the first published attempt to provide practical guidance on what is required to perform robust, quantitative HIA. Initial steps include profiling the affected populations, obtaining evidence from for postulated impacts, and determining how differences in subgoups' exposures and suscepibilities affect impacts. Using epidemiological evidence for HIA is different from carrying out a new study. Key steps in quantifying impacts are mapping the causal pathway, selecting appropriate outcome measures and selecting or developing a statistical model. Evidence from different sources is needed. For many health impacts, evidence of an effect may be scarce and estimates of the size and nature of the relationship may be inadequate. Assumptions and uncertainties must therefore be explicit. Modelled data can sometimes be tested against empirical data but sensitivity analyses are crucial. When scientific problems occur, discontinuing the study is not an option, as HIA is usually intended to inform real decisions. Both qualitative and quantitative elements of HIA must be performed robustly to be of value
Tachyon-Free Non-Supersymmetric Strings on Orbifolds
We discuss tachyon-free examples of (Type IIB on) non-compact
non-supersymmetric orbifolds. Tachyons are projected out by discrete torsion
between orbifold twists, while supersymmetry is broken by a Scherk-Schwarz
phase (+1/-1 when acting on space-time bosons/fermions) accompanying some even
order twists. The absence of tachyons is encouraging for constructing
non-supersymmetric D3-brane gauge theories with stable infrared fixed points.
The D3-brane gauge theories in our orbifold backgrounds have chiral N = 1
supersymmetric spectra, but non-supersymmetric interactions.Comment: 17 page
Uniqueness of the minimum of the free energy of the 2D Yang-Mills theory at large N
There has been some controversies at the large behaviour of the 2D
Yang-Mills and chiral 2D Yang-Mills theories. To be more specific, is there a
one parameter family of minima of the free energy in the strong region, or the
minimum is unique. We show that there is a missed equation which, added to the
known equations, makes the minimum unique.Comment: 8 pages,Late
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