11,436 research outputs found
Proton Decay and Related Processes in Unified Models with Gauged Baryon Number:
In unification models based on SU(15) or SU(16), baryon number is part of the
gauge symmetry, broken spontaneously. In such models, we discuss various
scenarios of important baryon number violating processes like proton decay and
neutron-antineutron oscillation. Our analysis depends on the effective operator
method, and covers many variations of symmetry breaking, including different
intermediate groups and different Higgs boson content. We discuss processes
mediated by gauge bosons and Higgs bosons parallely. We show how accidental
global or discrete symmetries present in the full gauge invariant Lagrangian
restrict baryon number violating processes in these models. In all cases, we
find that baryon number violating interactions are sufficiently suppressed to
allow grand unification at energies much lower than the usual GeV.Comment: (32 pages LATEX) [DOE-ER\,40757-022, CPP-93-22] {Small changes made
and two references added. This version will appear in Phys. Rev. D
Vagal Withdrawal and Sympathetic Overactivity Contribute to the Genesis of Early-Onset Pregnancy-Induced Hypertension
Objective. In this study, we have assessed sympathovagal imbalance (SVI) by spectral analysis of heart rate variability (HRV) that contributes to the genesis of early-onset PIH.
Methods. Body mass index (BMI), basal heart rate (BHR), blood pressure (BP) and HRV indices such as LFnu, HFnu, LF-HF ratio, mean RR, SDNN and RMSSD were assessed in normal pregnant women (Control group) and pregnant women having risk factors for PIH (Study group) at all the trimesters pregnancy. Retrospectively, those who did not develop PIH (Study group I) were separated from those who developed PIH (Study group II). Study group II was subdivided into early-onset and late-onset PIH. Sympathovagal balance (LF-HF ratio) was correlated with BMI, BHR and BP.
Results. LF-HF ratio was significantly high in study group II compared to study group I and control group, and in early-onset PIH group compared to the late-onset category at all the trimesters of pregnancy, which was significantly correlated with BHR and BP. Alteration in HFnu in early-onset category was more prominent than the alteration in LFnu.
Conclusion. Though the SVI in PIH is contributed by both sympathetic overactivity and vagal withdrawal, especially in early-onset type, SVI is mainly due to vagal inhibition
Stability analysis of an eco-epidemiological model incorporating a prey refuge
The present paper deals with the problem of a predator-prey model incorporating a prey refuge with disease in the prey-population. We assume the predator population will prefer only infected population for their diet as those are more vulnerable. Dynamical behaviours such as boundedness, permanence, local and global stabilities are addressed. We have also studied the effect of discrete time delay on the model. The length of delay preserving the stability is also estimated. Computer simulations are carried out to illustrate our analytical findings
Keypad mobile phones are associated with a significant increased risk of microbial contamination compared to touch screen phones
The use of mobile phones in the clinical environment by healthcare workers has become widespread. Despite evidence that these devices can harbour pathogenic micro-organisms there is little guidance on how to reduce contamination. Recently touchscreen phones with a single flat surface have been introduced. We hypothesise that bacterial contamination of phones used in hospitals will be lower on touchscreen devices compared to keypad devices. Sixty seven mobile phones belonging to health care workers were sampled. The median colony count for touchscreen phones and keypad devices was 0·09 colony forming units (cfu)/cm2 (interquartile range (IQR) 0.05–0·14) and 0·77 cfu/cm2 (IQR range 0·45–3.52) respectively. Colony counts were significantly higher on the keypad phones (Fisher’s exact test p<0.001). Multivariate analysis showed the type of phone (keypad vs. touch screen) was associated with increased colony counts (F-statistic 14.13: p<0.001). Overall, nine (13%) phones grew either meticillin resistant Staphylococcus aureus or vancomycin resistant enterococci. Eight (24%) keypad phones were contaminated with these organisms compared with one touch screen phone (3%). Our data indicate that touchscreen mobile phones are less contaminated than their keypad counterparts, and they are less likely to harbour pathogenic bacteria in the clinical setting
Investigations on the Flexural Strength and the Effect of b/h and l/b ratio on the Carbon Fiber Reinforced Epoxy Laminated Composites
In present day the use of fiber reinforced composites is increased remarkably in the various sectors of industries owing to its relative advantages especially in industries like aeronotics, automobile, ship buildingand in chemical industries, where the major emphasis is on weight reduction with a subtantial increase in the mechanical strengt
h of the component with enhanced durabli
ty by having properties like corrosive resistance,
anti reactive to various acidic reactions and to
with stand various climatic and temperature conditions.In this context carbon fibre reinforced laminated composites exhibit excellent mechanical
properties.Investigation of various properties is difficult in composite materials because of its complex
behavior further it is very difficult to evaluate the behavior of fiber laminated composites because
of its enhanced complexity,evaluation of properties
in composites is difficult with the addition of the fiber (carbon fiber)into the matrix. in this paper an investigation on the flexural properties of the carbon fiber reinforced laminates is carried out and the effect of bredth(b)to thickness(t)and the influence of the of length(l)to breadth(b),Aspect ratiois being evaluated and appropriate conclusions are drawn
Deformed Special Relativity and Deformed Symmetries in a Canonical Framework
In this paper we have studied the nature of kinematical and dynamical laws in
-Minkowski spacetime from a new perspective: the canonical phase space
approach. We discuss a particular form of -Minkowski phase space
algebra that yields the -extended finite Lorentz transformations
derived in \cite{kim}. This is a particular form of a Deformed Special
Relativity model that admits a modified energy-momentum dispersion law as well
as noncommutative -Minkowski phase space. We show that this system can
be completely mapped to a set of phase space variables that obey canonical (and
{\it{not}} -Minkowski) phase space algebra and Special Relativity
Lorentz transformation (and {\it{not}} -extended Lorentz
transformation). The complete set of deformed symmetry generators are
constructed that obeys an unmodified closed algebra but induce deformations in
the symmetry transformations of the physical -Minkowski phase space
variables. Furthermore, we demonstrate the usefulness and simplicity of this
approach through a number of phenomenological applications both in classical
and quantum mechanics. We also construct a Lagrangian for the
-particle.Comment: Revised version with change in Title and Abstract, No change in
mathematical content, Reference section enlarged, Discussion on Soccer Ball
Problem removed; Version to appear in PR
SU(16) grandunification: breaking scales, proton decay and neutrino magnetic moment
We give a detailed renormalization group analysis for the SU(16) grandunified
group with general breaking chains in which quarks and leptons transform
separately at intermediate energies. Our analysis includes the effects of Higgs
bosons. We show that the grandunification scale could be as low as GeV and give examples where new physics could exist at relatively low
energy ( GeV). We consider proton decay in this model and show that
it is consistent with a low grandunification scale. We also discuss the
possible generation of a neutrino magnetic moment in the range of to
with a very small mass by the breaking of the embedded
SU(2) symmetry at a low energy.Comment: (16 pages in REVTEX + 6 figures not included) OITS-49
Reliability of criteria used for sexing of hip bones
For demarking a male from a female hip bone, the reliability of three most commonly used parameters i.e. chilotic line index, ischio-pubic index and acetabulo-pubic index were checked on 205 hip bones (143 males & 62 females). For all the three parameters "demarking points" were worked out. None of the parameters were promising in indentifying sex as a very low percentage of bones could be identified. The study concluded that the reliability of all the above parameters is doubtful
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