201 research outputs found
Fetomaternal outcome in breech delivery
Background: Breech Presentation is the commonest of all malpresentations. Vaginal delivery of the breech presentations at term is associated with a much higher perinatal mortality and morbidity than that of vertex presentation. The objectives of the present study are to know the common causes leading to breech presentation. Further, to compare the different management protocols and outcome in different types of breech presentation. Also, to know the perinatal morbidity and mortality associated with different types of breech presentation nd comparison of perinatal morbidity and mortality with vaginal delivery against cesarean section.Methods: This is a retrospective study of randomized 100 cases of pregnant women in labour with breech presentations after 28 weeks or more attending C U Shah Medical College, Surendranagar, over a period of May 2012 to April 2014.Results: Out of 100 patients breech presentation was more common in booked patients and multigravida. In primi and multigravidae patients, caesarean delivery was more compared to assisted breech delivery. Perinatal outcome was good in majority of the patients in both extended and complete breech with an incidence of 94% and 88% respectively. perinatal outcome was good in caesarean section with 100% compared to assisted breech delivery 93%.Conclusions: The balanced decision about the mode of delivery on a case by case basis as well as conduct, training and regular drills of assisted breech delivery will go a long way to optimize the outcome of breech presentation like ours. Delivery of breech fetus when labor and delivery is supervised and or conducted by experienced obstetrician lowers maternal morbidity, neonatal morbidity and mortality
In-plane Magnetoconductivity of Si-MOSFET's: A Quantitative Comparison between Theory and Experiment
For densities above cm in the strongly
interacting system of electrons in two-dimensional silicon inversion layers,
excellent agreement between experiment and the theory of Zala, Narozhny and
Aleiner is obtained for the response of the conductivity to a magnetic field
applied parallel to the plane of the electrons. However, the Fermi liquid
parameter and the valley splitting obtained from
fits to the magnetoconductivity, although providing qualitatively correct
behavior (including sign), do not yield quantitative agreement with the
temperature dependence of the conductivity in zero magnetic field. Our results
suggest the existence of additional scattering processes not included in the
theory in its present form
Electron-electron interaction at decreasing
The contribution of the electron-electron interaction to conductivity is
analyzed step by step in gated GaAs/InGaAs/GaAs heterostructures with different
starting disorder. We demonstrate that the diffusion theory works down to , where is the Fermi quasimomentum, is the mean free
paths. It is shown that the e-e interaction gives smaller contribution to the
conductivity than the interference independent of the starting disorder and its
role rapidly decreases with decrease.Comment: 5 pages, 6 figure
Pantoea: A Versatile bacterial Candidate of Agricultural Importance
Genus Pantoea is a diverse group of the family Enterobacteriaceae which inhabit various ecological niches. Various species of Pantoea are found associated with a diverse host range that include plants, animals, insects and humans. Besides this Pantoea spp. has been widely distributed in nature including water, soil, dairy products, meat and fish. It is commonly associated with plants as epiphyte or pathogen. Pantoea was first recognized as a genus about 25 years ago, but since then, approximately 20 species with a wide range of characteristics have been discovered. Identification of plant-pathogenic Pantoea species is difficult, due to the high degree of phenotypic similarity between species of this genus and related Enterobacteriaceae. Pantoea species are typically characterized based on colony morphology, physiological and biochemical tests, and in some cases, fatty acid analysis or quinone composition. These have a wide range of plant hosts where they live as nonpathogenic endophytes as well as epiphytes that colonize the leaves, stems and roots. In this perspective, some Pantoea strains can be beneficial to the plant host by providing growth promoting substances such as the plant-growth hormone indole-acetic acid (IAA), phosphate solubilization or nitrogen fixation. Number of Pantoea species are also involved in bioremediation of various pesticides and organic chemical compounds. This indicates the potential to degrade some recalcitrant and xenobiotic compounds. Some Pantoea strains also provide effective protection to plants against various bacterial and fungal diseases and post-harvest fruit rots. On the other hand, some of the species are recognized as a human pathogen and has led to controversy as limited documented cases of P. agglomerans bacteremia and infections have been reported. Most of the cases reported among immunocompromised patients or the pediatric population. Thus, Pantoea is a multifaceted bacterium that plays a significant role in agriculture as a plant growth promoter by producing hormone like IAA, inorganic pollutant degradation by producing potent enzymes and also protects some plants against pathogens by producing antibacterial and antifungal compounds. In some cases, these also cause diseases in human beings. Therefore, this genus is very important for studies. In this review, the industrial, agricultural as well as ecological significance of the genus Pantoea is emphasized
Interactions in high-mobility 2D electron and hole systems
Electron-electron interactions mediated by impurities are studied in several
high-mobility two-dimensional (electron and hole) systems where the parameter
changes from 0.1 to 10 ( is the momentum relaxation
time). This range corresponds to the \textit{intermediate} and \textit
{ballistic} regimes where only a few impurities are involved in
electron-electron interactions. The interaction correction to the Drude
conductivity is detected in the temperature dependence of the resistance and in
the magnetoresistance in parallel and perpendicular magnetic fields. The
effects are analysed in terms of the recent theories of electron interactions
developed for the ballistic regime. It is shown that the character of the
fluctuation potential (short-range or long-range) is an important factor in the
manifestation of electron-electron interactions in high-mobility 2D systems.Comment: 22 pages, 11 figures; to appear in proceedings of conference
"Fundamental Problems of Mesoscopic Physics", Granada, Spain, 6-11 September,
200
Spin-orbit interaction and the 'metal-insulator' transition observed in two-dimensional hole systems
We present calculations of the spin and phase relaxation rates in GaAs/AlGaAs
-type quantum wells. These rates are used to derive the temperature
dependence of the weak-localization correction to the conductivity. In -type
quantum wells both weak localization and weak anti-localization are present due
to the strong spin-orbit interaction. When determining the total conductivity
correction one also have to include the term due to hole-hole interaction. The
magnitude of the latter depends on the ratio between the thermal energy and the
Fermi energy, and whether the system can be considered
as ballistic or diffusive (). We argue that due to the relatively low Fermi energy
and the moderate mobilities, in the -type systems in question, the
conductivity correction arising from hole-hole interactions is negligible at
the highest temperatures accessible in the experiments. Hence the
'metal-insulator' transition observed at these relatively high temperatures
could be caused by interference effects. We compare our calculations of the
weak anti-localization correction with the experimental results from different
independent groups with special emphasis on the experiments by Simmons et al.
We find good agreement between predicted and observed transistion density
.Comment: 6 pages, 4 figures. Accepted to PRB (15 June, 2002
Phase separation in the two-dimensional electron liquid in MOSFETs
We show that the existence of an intermediate phase between the Fermi liquid
and the Wigner crystal phases is a generic property of the two-dimensional pure
electron liqd in MOSFET's at zero temperature. The physical reason for the
existence of these phases is a partial separation of the uniform phases.
We discuss properties of these phases and a possible explanation of
experimental results on transport properties of low density electron gas in Si
MOSFET's. We also argue that in certain range of parameters the partial phase
separation corresponds to a supersolid phas e discussed in [AndreevLifshitz].Comment: 11 pages, 3 figure
Hall Coefficient in an Interacting Electron Gas
The Hall conductivity in a weak homogeneous magnetic field, , is calculated. We have shown that to leading order in
the Hall coefficient is not renormalized by the
electron-electron interaction. Our result explains the experimentally observed
stability of the Hall coefficient in a dilute electron gas not too close to the
metal-insulator transition. We avoid the currently used procedure that
introduces an artificial spatial modulation of the magnetic field. The problem
of the Hall effect is reformulated in a way such that the magnetic flux
associated with the scattering process becomes the central element of the
calculation.Comment: 23 pages, 15 figure
Preliminary results of a soft novel lumbar intervertebral prothesis (DIAM) in the degenerative spinal pathology
Summary The authors report a series of 43 patients su¤ering from lower limb pain, almost constantly associated with chronic or acute backpain, treated by microsurgical nerve root decompression and by implantation of a soft intervertebral prothesis (DIAM). Satisfying results were obtained in 97% of cases, inducing the authors to consider the device a reliable tool for curing low-back pain and sciatica. Selection criteria are exposed and discussed
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