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Tachyons and the causal paradox

Advances in molecular technologies challenge the different concepts of causality in biology, epidemiology and multistage mathematical models. The lack of integration of the different aspects of causality...Full Text Available

Causality Constrains Higher Curvature Corrections to Gravity

The author attempts to clear up the causal 'paradox' often associated with the existence of tacyons. This leads to a discussion of the nature of tachyon messages and the problems involved in their interpretation. (W.D.L.).

Tachyons in bi-metric theories of gravitation

We show that causality constrains the sign of quartic Riemann corrections to the Einstein-Hilbert action. Our constraint constitutes a restriction on candidate theories of quantum gravity.

2006-01-01

Assessing and Compensating for Zero-lag Correlation Effects in Time-lagged Granger Causality Analysis of fMRI

Some kinematical consequences of the causal tachyons possible in bi-metric theories are considered. (author).

Principles and Algorithms for Causal Reasoning with ...

Effective connectivity in brain networks can be studied using Granger causality analysis which is based on temporal precedence, while functional connectivity is usually derived using zero-lag...Full Text Available

2010-06-01

Answer to 'Information flow, causality, and the classical theory of tachyons'

... Missionaries and Cannibals, etc.) Since the shooting example is intended to be an example of general autonomous reasoning, we will avoid such ...

1989-05-01

A methodology to model causal relationships on offshore safety assessment focusing on human and organizational factors

Recently Basano (Int. J. Theor. Phys.; 16:715 (1977)) in a paper entitled 'Information Flow, Causality and the Classical Theory of Tachyons' commented on earlier work by the present authors. In answer to those comments it is pointed out that although 'Extended Relativity' seems to allow one to solve any causal paradoxes with both usual particles and tachyons nevertheless a number of paradoxes are continuously proposed. It has already been shown by the authors that tachyons possibly do not imply any causality violations even in macro-physics but Basano claimed that the procedure lead to new, different paradoxes. It is here demonstrated that such presumed difficulties do not exist. (U.K.).

British Library Electronic Table of Contents (United Kingdom)

IntroductionFocusing on people and organizations, this paper aims to contribute to offshore safety assessment by proposing a methodology to model causal relationships.MethodThe methodology is proposed in a general sense that it will be capable of accommodating modeling of multiple risk factors considered in offshore operations and will have the ability to deal with different types of data that may come from different resources. Reason's ?Swiss cheese?? model is used to form a generic offshore safety assessment framework, and Bayesian Network (BN) is tailored to fit into the framework to construct a causal relationship model. The proposed framework uses a five-level-structure model to address latent failures within the causal sequence of events. The five levels include Root causes level, Tr...

2008-01-01

Tachyons without paradoxes

Tachyon paradoxes, including causality paradoxes, have persisted within tachyon theories and left little hope for the existence of observable tachyons. A way is presented to solve the causality paradoxes, along with two other paradoxes, by the introduction of an absolute frame of reference in which a tachyon effect may never precede its cause. Relativity for ordinary matter is unaffected by this, even if the tachyons couple to ordinary particles. Violations of the principle of relativity due to the absolute frame would appear only in the case of free tachyons.

Information flow, causality, and the classical theory of tachyons

The human causal factors for all human error licensing operational events on Daya Bay nuclear power station since 1993 to 2003 are categorized, the trend of these causal factors is analyzed. The emphasis is placed on analyzing the deficiencies on complying with and executing regulations and procedures. The results provide directional reference for nuclear power station to improve human performance. (author)

2005-09-01

Crude oil shocks and stock markets: A panel threshold cointegration approach

Causal paradoxes arising in the tachyon theory have been systematically solved by using the reinterpretation principle as a consequence of which cause and effect no longer retain an absolute meaning. However, even in the tachyon theory, a cause is always seen to chronologically precede its effect, but this is obtained at the price of allowing cause and effect to be interchanged when required. A recent result has shown that this interchange-ability of cause and effect must not be unlimited if heavy paradoxes are to be avoided. This partial recovery of the classical concept of causality has been expressed by the conjecture that transcendent tachyons cannot be absorbed by a tachyon detector. In this paper the directional properties of the flow of information between two observers in relative motion and its consequences on the logical self-consistency of the theory of superluminal particles are analyzed. It is shown that the above conjecture does ...

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This paper proposes a panel threshold cointegration approach to investigate the relationship between crude oil shocks and stock markets for the OECD and non-OECD panel from January 1995 to December 2009. Nonlinear cointegration is confirmed for the oil-stock nexus in the panel. Because threshold cointegration is found, the threshold vector error correction models can be run to investigate the presence of asymmetric dynamic adjustment. The Granger causality tests demonstrate the existence of bidirectional long-run Granger causality between crude oil shocks and stock markets for these OECD and non-OECD countries. However, the short-run Granger causality between them is bidirectional under positive changes in the deviation and unidirectional under negative ones. Moreover, the speed of adjustm...

2011-01-01

Bi-directional causality in California's electricity and natural-gas markets

Bi-directional causality in California's electricity and natural-gas markets

The Granger instantaneous-causality test is applied to explore the potential causal relationships between wholesale electricity and natural-gas prices in California. The test shows these relationships to be bi-directional, and reveals California's electricity and natural-gas markets to be as inextricably intertwined as casual observation and theoretical considerations would suggest they ought to be. This meshing of markets exacerbated the effects of California's natural-gas crisis on the contemporaneous electricity crisis, while concurrently the electricity crisis may have contributed to the dysfunction in the national-gas market and helped to precipitate the natural-gas crisis. The finding supports an integrated approach, as opposed to a piecemeal approach, for formulating energy policy recommendations, not just in California but in the world at large. (author)

2006-10-01

Gene-Environment Interactions in Schizophrenia: Review of Epidemiological Findings and Future Directions

2006-10-01

Estimation of cancer incidence and mortality attributable to alcohol drinking in china

Concern is building about high rates of schizophrenia in large cities, and among immigrants, cannabis users, and traumatized individuals, some of which likely reflects the causal influence of environmental...Full Text Available

2008-11-01

Destructive effects of smoking on molecular and genetic factors of periodontal disease

BackgroundCancer constitutes a serious burden of disease worldwide and has become the second leading cause of death in China. Alcohol consumption is causally associated with the...Full Text Available

Decline of Ambient Air Pollution Levels and Improved Respiratory Health in Swiss Children

Many epidemiological evidences have proven the association between smoking and periodontal disease. The causality can be further established by linking findings of traditional epidemiological studies...Full Text Available

A path model of factors influencing morbidity and mortality in Ontario feedlot calves.

The causality of observed associations between air pollution and respiratory health in children is still subject to debate. If reduced air pollution exposure resulted in improved respiratory health...Full Text Available

2005-11-01

A NEW APPROACH TO UNDERSTANDING THE MOLECULAR MECHANISMS THROUGH WHICH ESTROGENS AFFECT COGNITION

The principles of path analysis and causal modelling are discussed. Path analysis was applied to three data sets to assess the relationship between group characteristics (number per group and "mixing"...Full Text Available

1986-01-01

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The Meaning of Cause and Prevent: The Role of Causal Mechanism

Traditional approaches to the study of hormones and cognition have been primarily observational or correlational in nature. Because this work does not permit causal relationships to be identified,...Full Text Available

2010-10-01

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How do people understand questions about cause and prevent? Some theories propose that people affirm that A causes B if A's occurrence makes a difference to B's occurrence in one way or another. Other theories propose that A causes B if some quantity or symbol gets passed in some way from A to B. The aim of our studies is to compare these theories' ability to explain judgements of causation and prevention. We describe six experiments that compare judgements for causal paths that involve a mechanism, i.e. a continuous process of transmission or exchange from cause to effect, against paths that involve no mechanism yet a change in the cause nevertheless brings about a change in the effect. Our results show that people prefer to attribute cause when a mechanism links cause to effect. In contr...

2011-01-01

Is XMRV a causal virus for prostate cancer?

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The potential association between xenotropic murine leukaemia virus-related gammaretrovirus (XMRV) and prostate cancer (PCa) has been documented since 2006. It is important for furthering our understanding of the biological mechanisms of PCa to ascertain whether this association is causal. To summarize the available information on the epidemiological and laboratory findings of the association, we conducted a literature search of the PubMed electronic database (from March 2006 to February 2011) to identify relevant published studies that examined the association between XMRV and PCa. Although several studies showed the positive association between XMRV and PCa, more recent studies did not support this conclusion. The positive findings might be due to contamination of human samples. Further ...

2011-01-01

How can supply networks increase firm value? A causal framework to structure the answer

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The recent literature in the field of supply chain management emphasizes the role of inter-organizational networks and the integration of vertical reproduction networks (supply chains) in particular as a key factor for value creation. However, the literature includes little empirical evidence. This situation suggests the need to appraise investments in such networks or supply chains carefully. How can a decision maker reliably assess the effect of investing in inter-organizational network arrangements on firm value? This article takes up this issue and suggests a framework consisting of five components to help answer the question. The task of the framework is to support the structuring and revelation of the causal chain between investments in the network on the one hand and the effect of t...

2009-01-01

Chronology protection in string theory

Urban Atmospheric Science

Many solutions of General Relativity appear to allow the possibility of time travel. This was initially a fascinating discovery, but geometries of this type violate causality, a basic physical law which is believed to be fundamental. Although string theory is a proposed fundamental theory of quantum gravity, geometries with closed timelike curves have resurfaced as solutions to its low energy equations of motion. In this paper, we will study the class of solutions to low energy effective supergravity theories related to the BMPV black hole and the rotating wave-D1-D5-brane system. Time travel appears to be possible in these geometries. We will attempt to build the causality violating regions and propose that stringy effects prohibit their construction. The proposed chronology protection agent for these geometries mirrors a mechanism string theory employs to resolve a class of naked singularities. (author)

2004-02-01

Environmental Research Database

DescriptionThis new research programme activity on Urban Atmospheric Science will deliver aspects of the NERC strategy: Next Generation Science for Planet Earth. It has been developed as part of the Environment, Pollution & Human Health theme. Research in the Environment, Pollution & Human Health theme is directed at elucidating key environmental processes that form part of a causal pathway between an environmental hazard and disease outcome, and providing a predictive capability of the risk to human heal [continued...

2012-01-01

Rotation in string cosmology

Rotation in string cosmology

We describe exact cosmological solutions with rotation and expansion in the low-energy effective string theory. These models are spatially homogeneous (closed Bianchi type IX) and they belong to the family of shear-free metrics which are causal (no closed timelike curves are allowed), admit no parallax effects and do not disturb the isotropy of the background radiation. The dilaton and the axion fields are nontrivial, in general, and we consider both cases with and without the central charge (effective cosmological constant)

2003-03-21

Relativistic semigroup, Lorentz group and tachyons. 1

2003-03-21

Lorentz noninvariance without tachyons in the Schwarzschild field

It is confirmed that actuality of tachyons and some unusual properties may be due to inadequate mathematical formalism based on the Lorentz group. Insertion of tachyons requires in addition to generalization of the causality principle also an extension of the relativistic invariance principle. It is proposed a way in the paper which removes a number of problematic situations in the tachyon problem.

Conventional and unconventional political participation

Considering the radial motion of a test particle in the Schwarzschild field in the hypothesis of local rotational invariance, the authors discuss the conditions to be satisfied by a physically acceptable model of broken SO(3,1) symmetry, and shown in particular that to preserve causality a breaking, even infinitesimal, makes necessarily impenetrable the interior of the Schwarzschild sphere.

1987-06-01

A class of finite one-loop light-cone integrals

A non-recursive model is proposed and empirically tested with data of opponents of nuclear power. In explaining conventional and unconventional participation the theory of collective action is applied and modified in two respects: the perceived influence on the elimination of collective evils are taken into account; the selective incentives considered are non-material ones. These modifications proved to be valid: the collective good variables and non-material incentives were important determinants for the two forms of participation. Another result was that there is a reciprocal causal relationship between conventional and unconventional participation.

1985-01-01

Mobile and stationary hydrogen power supply large scale applications - a not acceptable public risk? The technical, physical and chemical events course evaluation from accidents combined with the basics of causalities causing it - a necessity to avoid future ones

Using the manifestly causal gluon propagator in the light-cone gauge, we evaluate two one-loop Feynman integrals which appear in the computation of the three-gluon vertex correction in the two-component formalism of the Yang-Mills gauge fields. We conclude that they both are finite for {omega} -> 2, where {omega} is the dimensional regulator. They belong to a class of finite one-loop light-cone integrals. (author). 7 refs.

1992-10-01

Economic growth and pollutant emissions in Tunisia: An empirical analysis of the environmental Kuznets curve

Use of hydrogen in large scale applications is more usual than public is mentioning normally. Nevertheless reserve against hydrogen can be observed up to highest level decision-makers. Possibly a main reason can be found and eliminated by fixing: Some spectacular accidents happened in the past and found great interest. The publication of impressive accidents and the follow up of the events course was very carefully. The research in finding causalities in former decisions and follow up was not in the interest of some people or institutions. Important facts are even not noticed by insiders, but would have been very important for future decision makings and public acceptance of new applications. It will be demonstrated in three historical examples. Much more examples would be available and each one could help to find new applications for a saver and effective use of hydrogen in power supply. Awaking from new reserves could be avoided. Additional a safer handling would ...

2001-07-01

Economic growth and pollutant emissions in Tunisia: An empirical analysis of the environmental Kuznets curve

This paper investigates the relationship between economic growth and pollutant emissions for a small and open developing country, Tunisia, during the period 1961-2004. The investigation is made on the basis of the environmental Kuznets curve hypothesis, using time series data and cointegration analysis. Carbon dioxide (CO{sub 2}) and sulfur dioxide (SO{sub 2}) are used as the environmental indicators, and GDP as the economic indicator. Our results show that there is a long-run cointegrating relationship between the per capita emissions of two pollutants and the per capita GDP. An inverted U relationship between SO{sub 2} emissions and GDP has been found, with income turning point approximately equals to $1200 (constant 2000 prices) or to $3700 (in PPP, constant 2000 prices). However, a monotonically increasing relationship with GDP is found more appropriate for CO{sub 2} emissions. Furthermore, the causality results show that the relationship between income and ...

2010-02-15

Economic growth and pollutant emissions in Tunisia. An empirical analysis of the environmental Kuznets curve

This paper investigates the relationship between economic growth and pollutant emissions for a small and open developing country, Tunisia, during the period 1961-2004. The investigation is made on the basis of the environmental Kuznets curve hypothesis, using time series data and cointegration analysis. Carbon dioxide (CO2) and sulfur dioxide (SO2) are used as the environmental indicators, and GDP as the economic indicator. Our results show that there is a long-run cointegrating relationship between the per capita emissions of two pollutants and the per capita GDP. An inverted U relationship between SO2 emissions and GDP has been found, with income turning point approximately equals to $1200 (constant 2000 prices) or to $3700 (in PPP, constant 2000 prices). However, a monotonically increasing relationship with GDP is found more appropriate for CO2 emissions. Furthermore, the causality results show that the relationship between income and pollution in Tunisia is one ...

2010-02-01

Clean Technology Application : Kupola Model Burner for Increasing the Performance of Spent Accu Recycle

This paper investigates the relationship between economic growth and pollutant emissions for a small and open developing country, Tunisia, during the period 1961-2004. The investigation is made on the basis of the environmental Kuznets curve hypothesis, using time series data and cointegration analysis. Carbon dioxide (CO{sub 2}) and sulfur dioxide (SO{sub 2}) are used as the environmental indicators, and GDP as the economic indicator. Our results show that there is a long-run cointegrating relationship between the per capita emissions of two pollutants and the per capita GDP. An inverted U relationship between SO{sub 2} emissions and GDP has been found, with income turning point approximately equals to 1200 (constant 2000 prices) or to 3700 (in PPP, constant 2000 prices). However, a monotonically increasing relationship with GDP is found more appropriate for CO{sub 2} emissions. Furthermore, the causality results show that the relationship between income and ...

2010-02-15

Urinary catecholamines in iron deficiency anemia: effects of environmental temperature

Recycling of used battery for recovering lead done by either small household/small scale industries has been identified as a source of air pollution, especially by heavy metal (Pb). This condition give an adverse impact toward workers and societies. Technological aspect is one of the causal. The process apply an open system. Therefore, a lot of energy, as well as dust wasted to the air without prior treatment. For overcoming this condition, closed system by utilizing Cupola furnace will be offered as one of the alternatives clean technology application and to increase the recovering performance in order to set an effective and efficient result. (author)

2000-02-01

The tactical use of constraints and structure in diagnostic problem solving

Iron deficiency (ID) is associated with increased levels of norepinephrine (NE) in plasma and urine. They investigated the effect of 5-7 days exposure to three different environmental temperatures (10/sup 0/C, 24/sup 0/C, 30/sup 0/C) on urinary catecholamine levels to test the hypothesis that increased thermogenic activity is causal to this increased excretion in iron deficiency. Catecholamines were analyzed from acidified urine by HPLC-EC. The mean Hb in ID animals was 3.1 +/- .5 versus controls of 12.8 +/- 9. These data demonstrate that contrary to previous reports NE excretion is not normalized at a thermoneutral temperature and suggests a basic abnormality in peripheral SNS activity and NE metabolism in iron deficiency that is independent of environmental drive from thermogenesis.

1986-03-05

British Library Electronic Table of Contents (United Kingdom)

This paper presents a prescriptive account of diagnostic problem solving, or diagnosis, in quality and process control. This paper identifies a general strategy, named branch-and-prune, whose manifestations can be found in disciplines such as medical diagnosis, troubleshooting of devices, and model-based diagnosis in artificial intelligence. The work aims to offer a clear conceptualization of this strategy, based on the notions of structures for the search space, and constraints to the cause's nature.The idea is to treat the search space of candidate explanations as a tree structure, in which general and high-level causal directions are branched into more specific and detailed explanations. Constraints eliminate all but a few branches (pruning), which are explored in more detail. We enumer...

2011-01-01

The impact of Chernobyl on health and labour market performance

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Using longitudinal data from Ukraine we examine the extent of any long-lasting effects of exposure to the Chernobyl disaster on the health and labour market performance of the adult workforce. Variation in the local area level of radiation fallout from the Chernobyl accident is considered as a random exogenous shock with which to try to establish its causal impact on poor health, labour force participation, hours worked and wages. There appears to be a significant positive association between local area-level radiation dosage and perception of poor health, though much weaker associations between local area-level dosage and other specific self-reported health conditions. There is also some evidence to suggest that those who lived in areas more exposed to Chernobyl-induced radiation have sig...

2011-01-01

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Response to Kowalczynski on tachyons

Response to Kowalczynski on tachyons

The author answers and briefly and comment upon a paper on tachyons by J.K. Kowalczynski. Suitable answers are already contained in the recent literature about extended relativity (ER), apparently unknown to that author. His answer is threefold. (1) About causality: No paradoxes can be sensible discussed without studying in detail the tachyon-exchange dynamics; but once one knows tachyon mechanics, the solution of the paradox is straightforward. As an example, he exploits and solves the Tolman-Regge paradox. (2) About superluminal frames and transformations: I agrees that (as I has noted elsewhere) in four dimensions such language is unfortunate; it was borrowed from two dimensions, where it is completely justified. Formulations in terms of a new language can be found in my recent papers on ER. (3) The statement that the pseudo-Euclidean space-time is a particular Riemannian manifold is wrong. It is pseudo-Riemannian, or Lorentzian. When dealing with tachyons the ...

1987-09-01

Radio cellular phones and health: Up-to-date research on human health; Radiotelephones cellulaires et sante: mise au point des recherches portant sur la sante chez l'homme

Mechanisms of obesity-induced male infertility

Cellular telephones emit a radiofrequency electromagnetic field, part of which is absorbed in the user's head. Many studies have been conducted to look for their possible health hazard to human, at the experimental, epidemiological or clinical level. After a short recall on dosimetry, the author describes the state-of-the art about harmful and irreversible effects, up to now not confirmed, and about some benign symptoms which look absolutely actual. A causal relationship of the electromagnetic field on these benign symptoms is however not proven; other, studies are running to evaluate their possible long-term consequences. Interferences with cardiac pacemakers can easily be avoided by holding the telephone handset farther than 10 cm. (author)

1999-12-01

British Library Electronic Table of Contents (United Kingdom)

Male infertility, characterized by hypogonadism, decreased semen quality or ejaculatory dysfunction, accounts for approximately 20% of infertility cases. Obesity and metabolic dysfunction have been identified, among other causal factors, to contribute to male infertility. In the context of the Western world's `obesity epidemic', this article discusses three main biological mechanisms linking obesity to impaired male reproductive function: hypogonadism, testicular heat stress/hypoxia-induced apoptosis and endocrine disruption by `obesogens'. Among these, obesity-induced hypogonadism is undoubtedly the most clinically significant and is easily assessed. Rapidly expanding areas of research in this area include leptin modulation of kisspeptins and hypothalamic-pituitary-testicular hormone path...

2010-01-01

Introduction to symmetry and supersymmetry in quantum field theory

Impact of ocean pollution

This is a set of lecture notes given by the author at the Universities of Gottingen and Wroclaw. The text presents the axiomatic approach to field theory and studies in depth the concepts of symmetry and supersymmetry and their associated generators, currents and charges. It is intended as a one- semester course for graduate students in the field of mathematical physics and high energy physics. Contents: Introduction; Example of a Classical and Quantum Scalar Free Field Theory; Scene and Subject of the Drama. Axiom 1 and 2; Subject of the Drama; Principle of Relativity. Causality. Axiom 3, 4 and 5; Irreducibility of the Field Algebra and Scattering Theory. Axiom 6. Axiom O; Preliminaries about Physical Symmetries; Currents and Charges; Global Symmetries and Supersymmetries of the S - Matrix; Representations of the Super-Lie Algebra; The Case of Massless Particles; Fermionic Charges; Concluding Remarks.

1988-01-01

Human papillomavirus: science and technologies for the elimination of cervical cancer

Man's wastes are polluting the oceans from various sources and delivered by various routes. The result has been the loss of habitat and the irreversible altering of marine ecosystems. Development in the coastal zones and offshore activities that disrupt biologically sensitive areas have led to international negotiations to regulate these impacts and develop a law of the sea. Basic to international cooperation, however, is the need to develop answers to questions about the ecological consequences of development programs and the carrying capacity of the oceans. Current information does not demonstrate long-term global impacts, making it difficult to detect and predict incremental changes and causal relationships. Society needs to determine how much environmental damage it will accept and then to develop appropriate technology, such as biomonitoring. Society also needs to reexamine its positions on technology-based regulatory controls to see if the effects of ...

1981-03-01

British Library Electronic Table of Contents (United Kingdom)

Introduction: Academic research has made a significant advancement in understanding the viral causes of cervical cancer and generating the technology for prevention, both at the primary and secondary levels. Human papillomaviruses (HPVs) have been recognized as the first necessary cause of cervical cancer, the second most common cancer in women worldwide. Areas covered: This paper reviews the epidemiological evidence of the causality of HPV in relation to cervical cancer, other genital tract cancers and some cancers of the oral cavity and oropharynx. The review also covers HPV DNA testing as a screening tool. DNA probes of high-risk HPV types in different formats have been fully validated as primary screening tests, as secondary triage tests and as a prognostic marker following treatment o...

2011-01-01

Growth promotion and induction of resistance in tomato plant against Xanthomonas euvesicatoria and Alternaria solani by Trichoderma spp.

British Library Electronic Table of Contents (United Kingdom)

In tomato crop, the induction of resistance emerges as an important alternative for achieving the reduction of chemicals in disease control. This study aimed to evaluate the ability of 28 Trichoderma isolates to promote the growth of tomato seedlings and to induce systemic resistance (ISR) against Xanthomonas euvesicatoria and Alternaria solani, the causal agents of bacterial spot and early blight, respectively. Twelve isolates promoted the increase of plant dry matter mass (DMM) above 100%, showing the great potential of these strains. All isolates were able to colonize the root system of tomato plants. The plant growth-promoting isolates were further evaluated for potential elicitation of ISR. Treatment of the soil with all Trichoderma isolates provided protection in tomato plants from 2...

2011-01-01

From dispersion relations to spectral dimension - and back again

Enforcing Semantic Integrity on Untrusted Clients in Networked Virtual Environments

The so-called spectral dimension is a scale-dependent number associated with both geometries and field theories that has recently attracted much attention, driven largely though not exclusively by investigations of causal dynamical triangulations (CDT) and Horava gravity as possible candidates for quantum gravity. We advocate the use of the spectral dimension as a probe for the kinematics of these (and other) systems in the region where spacetime curvature is small, and the manifold is flat to a good approximation. In particular, we show how to assign a spectral dimension (as a function of so-called diffusion time) to any arbitrarily specified dispersion relation. We also analyze the fundamental properties of spectral dimension using extensions of the usual Seeley-DeWitt and Feynman expansions, and by saddle point techniques. The spectral dimension turns out to be a useful, robust and powerful probe, not only of geometry, but also of kinematics.

2011-01-01

Early universe in a generalized theory of gravitation

During the last years, large-scale simulations of realistic physical environments which support the interaction of multiple participants over the Internet have become increasingly available and economically significant, most notably in the computer gaming industry. Such systems, commonly called networked virtual environments (NVEs), are usually based on a client-server architecture where for performance reasons and bandwidth restrictions, the simulation is partially deferred to the clients. This inevitable architectural choice renders the simulation vulnerable to attacks against the semantic integrity of the simulation: malicious clients may attempt to compromise the physical and logical laws governing the simulation, or to alter the causality of events a posteriori. In this paper, we initiate the systematic study of semantic integrity in NVEs from a security point of view. We argue that naive policies to enforce semantic integrity involve intolerable network load, ...

2005-01-01

Bacterial vaginosis and other asymptomatic vaginal infections in pregnancy.

The standard Friedmann-Robertson-Walker (FRW) big bang model of the universe requires special initial conditions: the early universe is highly homogeneous and isotropic even though there exist causally disconnected regions (horizon problem). A plane symmetric (anisotropic) solution of field equations in a generalized theory of gravitation predicts the beginning of the universe as a vacuum instability at a specific fundamental time (which can be associated with the Planck time (tsub(p))), after which matter is created as the universe begins to expand. At a time t=tsub(c) there is a singular expansion, the anisotropy vanishes, and the physical horizon becomes infinite. Thereafter the solution of the field equations goes over into the FRW model. Thus the special initial conditions of the FRW model at the big bang singularity t=tsub(c) are predicted by the theory.

1982-05-01

The carbonate feedback system: interaction between stratigraphic accommodation, ecological succession and the carbonate factory; Le systeme de feed-back des carbonates: une interaction entre accomodation stratigraphique, succession ecologique et l`usine des carbonates

Preterm birth is a common cause of neonatal morbidity and mortality. Many asymptomatic genital infections have been associated with preterm birth, but attempts to determine a causal relationship between specific infections and preterm birth have been disappointing. Treatment trials of specific infections have generally failed to show a positive effect, and in some trials have shown a deleterious effect. Although there is a strong association between the presence of bacterial vaginosis and Trichomonas vaginalis in pregnancy and preterm birth, randomized treatment trials have failed to show a benefit of treatment of these organisms. Treatment of asymptomatic bacterial vaginosis or T. vaginalis to prevent preterm birth is not warranted. PMID:12112946

2001-08-01

The allusive cognitive deficit in paranoia: the case for mental time travel or cognitive self-projection.

In this paper, the analysis of carbonate depositional systems, using high resolution sequence stratigraphy, studies the ratio between change in accommodation space and skeletal carbonate production. This approach establishes the concurrent change in nature of facies belts (expansion, retraction and type) and fossil communities, within the detailed time frame in accommodation. Carbonate production is generally considered to be a fairly simple function of environmental conditions such as climate and water depth. However, data from several case studies also show a covariance between change in stratigraphic architecture of carbonate systems (the seaward or landward stepping stacking patterns of stratigraphic units) and charge in facies. Case studies include Carboniferous algal mound development in the Paradox Basin (USA), Devonian stromatoporoid reef development in Alberta (Canada), and Cenomanian rudistid shoal development in Oman. The hypotheses are tested on cases taken from the ...

1996-12-31

Solar wind driving of magnetospheric ULF waves: Field line resonances driven by dynamic pressure fluctuations

Delusional beliefs are characteristic of psychosis and, of the delusions, the paranoid delusion is the single most common type associated with psychosis. The many years of research focused on neurocognition in schizophrenia, using standardized neurocognitive tests, have failed to find conclusive cognitive deficits in relation to positive symptoms. However, UK-based psychological research has identified sociocognitive anomalies in relation to paranoid thinking in the form of theory of mind (ToM), causal reasoning and threat-related processing anomalies. Drawing from recent neuroscientific research on the default mode network, this paper asserts that the common theme running through the psychological tests that are sensitive to the cognitive impairment of paranoia is the need to cognitively project the self through time, referred to as mental time travel. Such an understanding of the cognitive roots of paranoid ideation provides a synthesis between psychological and ...

2010-08-01

Radiation induced micrencephaly in guinea pigs

Several observational studies suggest that solar wind dynamic pressure fluctuations can drive magnetospheric ultra-low frequency (ULF) waves on the dayside. To investigate this causal relationship, we present results from Lyon-Fedder-Mobarry (LFM) global, three-dimensional magnetohydrodynamic (MHD) simulations of the solar wind-magnetosphere interaction. These simulations are driven with synthetic solar wind input conditions, where idealized ULF dynamic pressure fluctuations are embedded in the upstream solar wind. In three of the simulations, a monochromatic, sinusoidal ULF oscillation is introduced into the solar wind dynamic pressure time series. In the fourth simulation, a continuum of ULF fluctuations over the 0-50 mHz frequency band is introduced into the solar wind dynamic pressure time series. In this numerical experiment, the idealized solar wind input conditions allow us to study only the effect of a fluctuating solar wind dynamic pressure, while holding ...

2010-01-01

Non local theories: New rules for old diagrams

A brain weight deficit of about 70 mg was induced at doses of approximately 75-mGy and a deficit of 60 mg was induced at 100 mGy. This confirms the effects projected and observed by Wanner and Edwards. Although the data do not demonstrate a clear dose-response relationship between the 75-mGy and 100-mGy groups, the data are statistically consistent with a dose-response effect because of the overlapping confidence intervals. The lack of a statistically significant observation is most likely related to the small difference in doses and the limited numbers of animals examined. There are several factors that can influence the brain weight of guinea pig pups, such as caging and housing conditions, the sex of the animal, and litter size. These should be taken into account for accurate analysis. Dam weight did not appear to have a significant effect. The confirmation of a micrencephalic effect induced x rays at doses of 75-mGy during this late embryonic stage of development is consistent with ...

2006-04-20

Magical Thinking in Somatoform Disorders: An Exploratory Study among Patients with Suspected Allergies.

We show that a general variant of the Wick theorems can be used to reduce the time ordered products in the Gell-Mann and Low formula for a certain class on non local quantum field theories, including the case where the interaction Lagrangian is defined in terms of twisted products. The only necessary modification is the replacement of the Stueckelberg-Feynman propagator by the general propagator (the 'contractor' of Denk and Schweda) D(y-y';#tau#-#tau#')=(1)/i(#DELTA#_+(y-y')#theta#(#tau#-#tau#')+#DELTA#+(y'-y)#theta#(#tau#'-#tau#)), where the violations of locality and causality are represented by the dependence of #tau#,#tau#' on other points, besides those involved in the contraction. This leads naturally to a diagrammatic expansion of the Gell-Mann and Low formula, in terms of the same diagrams as in the local case, the only necessary modification concerning the Feynman rules. The ordinary local theory is easily recovered as a special case, and there is a ...

2004-08-01

Emission factors of polybrominated diphenyl ethers (PBDEs) from plastics processing and recycling facilities

Background: In order to reconceptualize somatoform disorders (SFDs), the psychological characteristics of SFD patients are increasingly investigated. The cognitive style of magical thinking (MT) has not been studied so far in patients with SFDs. Sampling and Methods: In a cross-sectional study, 201 allergy workup patients were interviewed using the Structured Clinical Interview for DSM-IV; they answered a set of self-report questionnaires including the Schizotypal Personality Questionnaire subscale for MT and the Patient Health Questionnaire (PHQ). The expression of MT was explored in 61 patients with SFDs compared to 140 patients without SFDs. Results: Patients with SFDs reached higher scores of MT, also when controlled for gender, depression, and anxiety. In particular, they stated more frequently that they were believers in telepathy (64 vs. 44%) and clairvoyance (43 vs. 16%). MT correlated only weakly with somatization/somatic symptom severity, depression, and anxiety. Conclusions: ...

2011-06-09

Effect of fatiguing exercise on longitudinal bone strain as related to stress fracture in humans.

With regard to polybrominated diphenyl ether (PBDE), there is few scientific knowledge on the emission patterns into the environment and exposure pathways to humans, and basic information is insufficient to consider what measures effective are. For the purpose of promoting risk reduction of target substances more effectively and efficiently, it is desirable to comprehend accurately the causal chain from the target substances utilization to the risk intake, and to evaluate the measures covering the whole applications of target substances. As the existing researches on the PBDE emission inventory, there are EU risk assessment report (European Chemical Bureau 2000, 2002, 2003), Danish EPA (1999), Palm et al.(2002) and Alcock et al. (2003). In addition, emissions of DecaBDE are published in TRI (Toxic Release Inventory) of US EPA. However, the primary information of the previous inventories is often the same and estimations based on the measured values are few. In ...

2004-09-15

Diesel engine exhaust and lung cancer: An unproven association

Muscular fatigue in the training athlete or military recruit has been hypothesized to cause increased bone strain that may contribute to the development of a stress fracture. Under normal circumstances, muscles exert a protective effect by contracting to reduce bending strains on cortical bone surfaces. In vivo strain studies in dogs show that muscle fatigue following strenuous exercise elevates bone strain and changes strain distribution. However, a similar experiment has yet to be performed in humans. The purpose of this work was to test the hypothesis in humans that strenuous fatiguing exercise causes an elevation in bone strain. It was also hypothesized that this elevation is greater in younger people than in older people due to the decline in muscle strength and endurance that normally occurs with age. To test these hypotheses, strain in the tibiae of seven human volunteers was measured during walking before and after a period of fatiguing exercise. Neither hypothesis was ...

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Assessing digital control system dependability using the dynamic flowgraph methodology

The risk of lung cancer associated with diesel exhaust has been calculated from 14 case-control or cohort studies. We evaluated the findings from these studies to determine whether there is sufficient evidence to implicate diesel exhaust as a human lung carcinogen. Four studies found increased risks associated with long-term exposure, although two of the four studies were based on the same cohort of railroad workers. Six studies were inconclusive due to missing information on smoking habits, internal inconsistencies, or inadequate characterization of diesel exposure. Four studies found no statistically significant association. It can be concluded that short-term exposure to diesel engine exhaust (20 years) increases the risk of lung cancer for locomotive engineers, brakemen, and diesel engine mechanics. There is inconsistent evidence on the effects of long-term exposure to diesel exhaust in the trucking industry. There is no evidence for a joint effect of diesel exhaust and cigarette ...

1995-09-01

Antilock brakes and the risk of driver injury in a crash: a case-control study.

Dynamic Flowgraph Methodology (DFM) is a methodological approach to modeling and analyzing the behavior of software-driven embedded systems for the purpose of reliability/safety assessment and verification. The methodology has two fundamental goals: (a) to identify how certain postulated events may occur in a system and (b) to identify an appropriate testing strategy based on an analysis of system functional behavior. To achieve these goals, the methodology employs a modeling framework in which system models are developed in terms of causal relationships between physical variables and temporal characteristics of the execution of software modules. These models are then analyzed to determine how a certain state (desirable or undesirable) can be reached. This is done by developing timed fault trees, which take the form of logical combinations of static trees relating system parameters at different points in time. The prime implicants (multistate analog of minimal cut ...

1993-01-01

Spin-s tachyons and the propagation of tachyon waves. Part B

While antilock brakes can improve steering and reduce stopping distance in some test situations, there is little evidence that they reduce the risk of crash-related injury. We sought to estimate the association between presence of antilock brakes and the risk of driver injury. We conducted a case-control study using claims data from the Insurance Corporation of British Columbia, Canada, for passenger vehicles insured during July 1, 2003, to June 30, 2004. Cases were 5000 vehicles with a driver crash injury during the study period. Controls were 49,994 vehicles insured at the mid-point of the study interval. The adjusted risk ratio for a crash with driver injury in a vehicle with antilock brakes was 1.06 (95% confidence interval, 0.95-1.17), compared with a vehicle without antilock brakes. If this estimated association is causal, antilock brakes do not prevent crash-related driver injuries. PMID:17320027

2007-02-22

Insights in the use of health care services in chronic benign pain in childhood and adolescence.

The propagation of bradyon and tachyon wave functions can be compared by considering them as cases of normal and anomalous dispersion and using the ideas of Brillouin which where developed in order to describe the propagation of light in a transparent medium near an adsorption line. It is found that if a wave packet, or pulse, is formed using a superposition of waves moving only in the positive x direction, including both positive energies, it will propagate superluminally for both bradyons and tachyons. If non-physical states, imaginary moments and energies, are included in the superposition, both types of waves will propagate subluminally and remain within the light cone. This last result has also been obtained by Fox, Kuper and Lipson and Strnad and Kodre for tachyons when they included imaginary energies in their superposition. However, these approaches allow the tachyon to be localizable in space and can lead to divergences in the wave packet. If all the physical states ...

Inherited partial direct duplication of 11q: First report and possible association with a midline developmental field defect

The utilization of health care services in children and adolescents with chronic benign pain was studied in a Dutch population sample of 254 chronic pain sufferers aged 0-18 years. Children and adolescents who had reported chronic pain (continuous or recurrent pain >3 months) in our previous prevalence study were asked to keep a 3-week diary on their pain and to fill out questionnaires on background factors, health care use and the impact of pain. Parent ratings were used for children aged 0-11 years, self-report was used in adolescents (12-18 years). In a 3-month period, in 53.4% of the cases medication was used for pain, and general practitioners and specialists were consulted for pain in 31.1% and 13.9% of subjects, respectively. Physiotherapists, psychologists and alternative health providers were visited by 11.5, 2.8, and 4.0%, respectively. In the preceding year, 6.4% had been hospitalized due to pain. The most important factors linked to utilizing medical services were ...

2001-11-01

Classical tachyons and possible applications

A 36-year-old woman underwent amniocentesis for advanced maternal age. The fetal karyotype had an extra dark staining G band on the long arm of chromosome 11 with no other identifiable abnormalities. FISH studies using a chromosome 11 paint probe confirmed the origin of the extra band. The abnormality was identified as a partial duplication of 11q: 46,XX dir dup (11)(q13.5q21) or (q21q23.1). The specific duplicated band could not be identified with certainty. Detailed fetal sonograms were normal. Family studies revealed the identical duplication in the mother but normal karyotypes in both maternal grandparents. The mother had strabismus and a short tongue frenulum which required surgical correction. Menses occurred late in adolescence and complete development of secondary sexual characteristics was delayed until adulthood. An infertility evaluation revealed duplication of the uterus, cervix, and vagina. An evaluation for metorrhagia identified a pituitary adenoma which was resected. ...

1994-09-01

Change of the mass of an accelerated charge as a dynamic manifestation of the clock paradox

This article is divided in five parts, the first one having nothing to do with tachyons. In fact, to prepare the ground, in part I (sect.2) we shall merely show that special relativity - even without tachyons - can be given a form such to describe both particles and antiparticles. Part II is the largest one: initially, after some historical remarks and having revisited the postulates of special relativity, we presnt a review of the elegant ''model theory'' of tachyons in two dimensions; passing then to four dimensions, we review the main results of the classical theory of tachyons that do not depend on the existence of Superluminal reference frames (or that are at least independent of the explicit form of the Superluminal Lorentz ''transformations''). In particular, we discuss how tachyons would look like, i.e. their apparent ''shape''. Last but not least, all the common ...

1986-01-01

A designed screening study with prespecified combinations of factor settings

Mass shift of accelerated charges-sources of a massive vector and massive scalar fields, are considered in an approximation which is classical with respect to the charge motion but quantum with respect to their interaction with their proper field. For uniformly accelerated charges the mass shifts are expressed in terms of cylindrical functions of the quantum parameter ..mu..c/sup 3//h/2..pi..w/sub 0/ which is the ratio of the mass ..mu.. of the proper field quanta to the charge acceleration w/sub 0/. For finite positive values of the parameter both the imaginary and real parts of the shifts are nonvanishing and negative. For ..mu -->..0 the real part of the mass shift of a vector charge tends to the classical value -..cap alpha..h/2..pi..w/sub 0//2c/sup 3/ obtained earlier, thereas that of the scalar charge tends to zero. These and other properties of the shifts as functions of ..mu.. are studied by taking into account the locality of interaction, unitarity and ...

1982-05-01

Sources of competitive advantage and business performance in the European meat processing industry

In many applications, the experimenter has limited options about what factor combinations can be chosen for a designed study. Consider a screening study for a production process involving five input factors whose levels have been previously established. The goal of the study is to understand the effect of each factor on the response, a variable that is expensive to measure and results in destruction of the part. From an inventory of available parts with known factor values, we wish to identify a best collection of factor combinations with which to estimate the factor effects. Though the observational nature of the study cannot establish a causal relationship involving the response and the factors, the study can increase understanding of the underlying process. The study can also help determine where investment should be made to control input factors during production that will maximally influence the response. Because the factor combinations are observational, the ...

2009-01-01

DEFF Research Database (Denmark)

1. The aim of the paper is to investigate the relative importance of three sets of sources of competitive advantages on business performance in a specific industry context, ie the European meat processing industry. The three sets of competitive sources are Firm Specific Advantages (FSAs), Localizational Specific Advantages (LSAs) and Relationship Specific Advantages (RSAs). Based on a literature study, each set of competitive advantages is briefly described in terms of their theoretical antecedents. Seven hypotheses are formulated regarding the direct as well as the indirect relationships between the FSAs, LSAs and RSAs and business performance. Also, the direction of causality between the various sets of explanatory variables is considered. The hypotheses are combined in a structural modelling of firm competition. 2. Data and measurements are derived from a survey in the European meat processing industry in which 133 meat processors from 10 EU countries agreed to ...

1999-01-01

The Integrated Status and Effectiveness Monitoring Program : Expansion of Existing Smolt Trapping Program and Steelhead Spawner Surveys : March 1st, 2008 - February 28th, 2009.