RECENT ADVANCES IN SUPERSTRING PERTURBATION THEORY

1990 ◽  
Vol 05 (06) ◽  
pp. 367-380 ◽  
Author(s):  
ERIC D'HOKER
Keyword(s):  
Perturbation Theory ◽  
String Theory ◽  
Quantum Gravity ◽  
Light Cone ◽  
Lorentz Invariance ◽  
Covariant Approach ◽  
Recent Advances ◽  
Made In

Recent advances made in the understading of the Ramond-Neveu-Schwarz formulation of superstring perturbation theory are reviewed. The role of chiral splitting, in terms of which a consistent GSO projected formula is obtained to all loop orders, is explained. Equivalence of the manifestly convariant Polyakov amplitudes with the manifestly unitary light-cone amplitudes is shown, thus establishing unitarity of the covariant approach and Lorentz invariance of the light-cone approach. Some implications for string theory and quantum gravity are pointed out.

scholarly journals QUANTUM GRAVITY AND TURBULENCE

2010 ◽  
Vol 19 (14) ◽  
pp. 2311-2317 ◽  
Author(s):  
VISHNU JEJJALA ◽  
DJORDJE MINIC ◽  
Y. JACK NG ◽  
CHIA-HSIUNG TZE
Keyword(s):  
String Theory ◽  
Quantum Gravity ◽  
Space Time ◽  
Recent Advances

We apply recent advances in quantum gravity to the problem of turbulence. Adopting the AdS/CFT approach we propose a string theory of turbulence that explains the Kolmogorov scaling in 3 + 1 dimensions and the Kraichnan and Kolmogorov scalings in 2 + 1 dimensions. In the gravitational context, turbulence is intimately related to the properties of space–time or quantum foam.

scholarly journals Recent advances in understanding of the pathogenesis of ANCA-associated vasculitis

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1113 ◽  
Author(s):  
Maria Prendecki ◽  
Charles D. Pusey
Keyword(s):  
Side Effects ◽  
Treatment Strategies ◽  
Current Treatment ◽  
Systemic Autoimmune Diseases ◽  
Treatment Protocols ◽  
Recent Advances ◽  
Recent Developments ◽  
The Complement System ◽  
Made In

Anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitides (AAV) are rare systemic autoimmune diseases characterised by inflammation of small blood vessels. Recent developments have been made in our understanding of the pathogenesis of these diseases, including the pathogenic role of ANCA, neutrophils and monocytes as mediators of injury, dysregulation of the complement system, and the role of T and B cells. Current treatment strategies for AAV are based on broad immunosuppression, which may have significant side effects. Advances in understanding of the pathogenesis of disease have led to the identification of new therapeutic targets which may lead to treatment protocols with less-toxic side effects. The aim of this review is to summarise current information and recent advances in understanding of the pathogenesis of AAV.

On the mass-independent renormalization scheme

1981 ◽  
Vol 59 (10) ◽  
pp. 1327-1333 ◽  
Author(s):  
Gerry McKeon
Keyword(s):  
Perturbation Theory ◽  
Quantum Electrodynamics ◽  
Renormalization Scheme ◽  
Second Order ◽  
Point Of View ◽  
Dimension Function ◽  
Order Coefficient ◽  
Mass Dimension ◽  
Made In

A calculation of the second order coefficient of the anomalous mass dimension function γm of Weinberg is made in quantum electrodynamics using the techniques of Sen and Sundaresan. The role of this quantity in perturbation theory is discussed from the point of view of the "Principle of Minimal Sensitivity" criterion of Stevenson.

scholarly journals Pathological implications of cell cycle re-entry in Alzheimer disease

2010 ◽  
Vol 12 ◽  
Author(s):  
David J. Bonda ◽  
Hyun-pil Lee ◽  
Wataru Kudo ◽  
Xiongwei Zhu ◽  
Mark A. Smith ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Alzheimer Disease ◽  
Neurofibrillary Tangles ◽  
Therapeutic Intervention ◽  
Amyloid Β ◽  
Regulatory Proteins ◽  
Early Event ◽  
Recent Advances ◽  
Made In

The complex neurodegeneration underlying Alzheimer disease (AD), although incompletely understood, is characterised by an aberrant re-entry into the cell cycle in neurons. Pathological evidence, in the form of cell cycle markers and regulatory proteins, suggests that cell cycle re-entry is an early event in AD, which precedes the formation of amyloid-β plaques and neurofibrillary tangles (NFTs). Although the exact mechanisms that induce and mediate these cell cycle events in AD are not clear, significant advances have been made in further understanding the pathological role of cell cycle re-entry in AD. Importantly, recent studies indicate that cell cycle re-entry is not a consequence, but rather a cause, of neurodegeneration, suggesting that targeting of cell cycle re-entry may provide an opportunity for therapeutic intervention. Moreover, multiple inducers of cell cycle re-entry and their interactions in AD have been proposed. Here, we review the most recent advances in understanding the pathological implications of cell cycle re-entry in AD.

scholarly journals DOES DLCQ S-MATRIX HAVE A COVARIANT CONTINUUM LIMIT?

2001 ◽  
Vol 16 (33) ◽  
pp. 2177-2185 ◽  
Author(s):  
MASA-AKI TANIGUCHI ◽  
SHOZO UEHARA ◽  
SATOSHI YAMADA ◽  
KOICHI YAMAWAKI
Keyword(s):  
Perturbation Theory ◽  
String Theory ◽  
Continuum Limit ◽  
Zero Mode ◽  
Great Care ◽  
S Matrix

We develop a systematic DLCQ perturbation theory and show that DLCQ S-matrix does not have a covariant continuum limit for processes with p+=0 exchange. This implies that the role of the zero mode is more subtle than ever considered in DLCQ and hence must also be treated with great care in nonperturbative approach. We also make a brief comment on DLCQ in string theory.

scholarly journals Emergence of stringlike physics from Lorentz invariance in loop quantum gravity

2014 ◽  
Vol 23 (12) ◽  
pp. 1442023 ◽  
Author(s):  
Rodolfo Gambini ◽  
Jorge Pullin
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
String Theory ◽  
Quantum Gravity ◽  
Loop Quantum Gravity ◽  
Lorentz Invariance ◽  
Spherically Symmetric ◽  
Quantum Field ◽  
Spin Network ◽  
Symmetric Quantum

We consider a quantum field theory on a spherically symmetric quantum spacetime described by loop quantum gravity. The spin network description of spacetime in such a theory leads to equations for the quantum field that are discrete. We show that to avoid significant violations of Lorentz invariance, one needs to consider specific nonlocal interactions in the quantum field theory similar to those that appear in string theory. This is the first sign that loop quantum gravity places restrictions on the type of matter considered, and points to a connection with string theory physics.

Recent Advances in Cochlear Neurotransmission: Physiology and Pathophysiology

Physiology ◽  
1995 ◽  
Vol 10 (4) ◽  
pp. 178-183
Author(s):  
R Pujol ◽  
M Eybalin ◽  
J-L Puel
Keyword(s):  
Considerable Progress ◽  
Clinical Implications ◽  
Recent Advances ◽  
Olivocochlear System ◽  
Made In

Recently, considerable progress has been made in the field of cochlear neurotransmitters. The glutamatergic nature of primary auditory synapses and related excitotoxic properties have strong pathophysiological consequences and clinical implications. Neurochemical advances also account for a much better understanding of the role of different components of the efferent olivocochlear system.

TWO DIMENSIONAL QUANTUM GRAVITY AND STRINGS

1990 ◽  
Vol 05 (10) ◽  
pp. 1833-1859 ◽  
Author(s):  
A.A. TSEYTLIN
Keyword(s):  
String Theory ◽  
Quantum Gravity ◽  
Conformal Factor ◽  
Target Space ◽  
Effective Theory ◽  
Two Dimensional ◽  
Conformal Gauge

We discuss some recent suggestions about a relation between 2-d quantum gravity and string theory. We consider the general 2-d σ model with D-dimensional target space coupled to 2-d quantum gravity and give arguments in favor of the conjecture that the effective theory which describes this system in the conformal gauge may be interpreted as a a model with a D+1-dimensional target space with the conformal factor of the metric playing the role of the D+1 coordinate. The latter σ model must be Weyl invariant while the original one may be arbitrary. The conformal “split” invariance which must be present in the conformal gauge imposes no restrictions on the original σ model couplings, but restricts the additional (D+1-dimensional) couplings which appear in the D+1-dimensional σ model.

ASPECTS IN BUILDING A COMPANY WEB-SITE AND ITS ROLE FOR THE DEVELOPMENT OF BUSINESS

2018 ◽  
pp. 117-124
Author(s):  
Petar Halachev ◽  
Victoria Radeva ◽  
Albena Nikiforova ◽  
Miglena Veneva
Keyword(s):  
Life Cycle ◽  
Web Site ◽  
The Internet ◽  
A Company ◽  
The Web ◽  
Design Construction ◽  
Made In ◽  
Site Types

This report is dedicated to the role of the web site as an important tool for presenting business on the Internet. Classification of site types has been made in terms of their application in the business and the types of structures in their construction. The Models of the Life Cycle for designing business websites are analyzed and are outlined their strengths and weaknesses. The stages in the design, construction, commissioning, and maintenance of a business website are distinguished and the activities and requirements of each stage are specified.

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