638 research outputs found
Exploring the Causes of Low Immunization Status in School Going Children
Background: Although a definitive immunization program has been advocated for children in our country, the immunization coverage is far from satisfactory. There is paucity of survey studies related to immunization pattern. Objective: This study has been undertaken to explore the social and attitudinal factors with parents resulting into adverse immunization. Material and Methods: The study was school based cross-sectional study conducted in 50 schools of Indore district selected by random sampling from three groups. Information was collected from parents by providing pre-tested questionnaire. Result: Association of parent’s literacy and socioeconomic status with successful immunization could be established. Overall coverage rate with vaccines was poor in school going girls as compared to the boys; proving thereby that gender discrimination exists putting girls in disadvantageous position. Conclusion: It can be expected that the immunization status of school children will improve if identified risk factors such as parental education, socioeconomic status, awareness status are improved and attitudinal gender discrimination is curbed
The formation of super-Earths and mini-Neptunes with giant impacts
The majority of discovered exoplanetary systems harbour a new class of planets, bodies that are typically several times more massive than the Earth but that orbit their host stars well inside the orbit of Mercury. The origin of these close-in super-Earths and mini-Neptunes is one of the major unanswered questions in planet formation. Unlike the Earth, whose atmosphere contains less than 10[superscript −6] of its total mass, a large fraction of close-in planets have significant gaseous envelopes, containing 1–10 per cent or more of their total mass. It has been proposed that close-in super-Earths and mini-Neptunes formed in situ either by delivery of 50–100 M⊕ of rocky material to the inner regions of the protoplanetary disc or in a disc enhanced relative to the minimum mass solar nebula. In both cases, the final assembly of the planets occurs via giant impacts. Here we test the viability of these scenarios. We show that atmospheres that can be accreted by isolation masses are small (typically 10[superscript −3]–10[superscript −2] of the core mass) and that the atmospheric mass-loss during giant impacts is significant, resulting in typical post-giant impact atmospheres that are 8 × 10[superscript −4] of the core mass. Such values are consistent with terrestrial planet atmospheres but more than an order of magnitude below atmospheric masses of 1–10 per cent inferred for many close-in exoplanets. In the most optimistic scenario in which there is no core luminosity from giant impacts and/or planetesimal accretion, we find that post-giant impact envelope accretion from a depleted gas disc can yield atmospheric masses that are several per cent the core mass. If the gravitational potential energy resulting from the last mass doubling of the planet by giant impacts is released over the disc dissipation time-scale as core luminosity, then the accreted envelope masses are reduced by about an order of magnitude. Finally we show that, even in the absence of type I migration, radial drift time-scales due to gas drag for many isolation masses are shorter than typical disc lifetimes for standard gas-to-dust ratios. Given these challenges, we conclude that most of the observed close-in planets with envelopes larger than several per cent of their total mass likely formed at larger separations from their host stars
A Review of Methods Employed to Identify Flicker Producing Sources
Because of increasing requirements of the present consumers and industrial units utilizing sensitive loads, there is need of good power quality in order to retain the power quality standards. Nowadays the study of the voltage flicker is becoming essential part of power quality studies. The flicker is typically the effect of a rapidly changing load which is large with respect to the short circuit ability of an electrical supply system. The inferior effects of voltage flicker include malfunctioning of power electronic equipment. Also it causes annoying effects to human. Hence detection of the flicker source is an essential step in the power quality assessment process. This paper delivers a review about methods used to identify flicker producing loads in accordance with IEC 61000-4-15. Once the report related to the disturbance place is known, an investigation and corrective action can be accordingly carried out. Also a method based upon Discrete Wavelet Transform and Artificial Neural Network is proposed to detect initial instance of occurrence of flicker
Stealing the Gas: Giant Impacts and the Large Diversity in Exoplanet Densities
Although current sensitivity limits are such that true solar system analogs remain challenging to detect, numerous planetary systems have been discovered that are very different from our own solar system. The majority of systems harbor a new class of planets, bodies that are typically several times more massive than the Earth but orbit their host stars well inside the orbit of Mercury. These planets frequently show evidence for large hydrogen and helium envelopes containing several percent of the planet's mass and display a large diversity in mean densities. Here we show that this wide range can be achieved by one or two late giant impacts, which are frequently needed to achieve long-term orbital stability in multiple planet systems once the gas disk has disappeared. We demonstrate using hydrodynamical simulations that a single collision between similarly sized exoplanets can easily reduce the envelope-to-core-mass ratio by a factor of two and show that this leads to a corresponding increase in the observed mean density by factors of two to three. In addition, we investigate how envelope mass loss depends on envelope mass, planet radius, semimajor axis, and the mass distribution inside the envelope. We propose that a small number of giant impacts may be responsible for the large observed spread in mean densities, especially for multiple-planet systems that contain planets with very different densities and have not been significantly sculpted by photoevaporation
The Formation of Super-Earths and Mini-Neptunes with Giant Impacts
The majority of discovered exoplanetary systems harbour a new class of
planets, bodies typically several times more massive than Earth but orbiting
their host stars well inside the orbit of Mercury. The origin of these close-in
super-Earths and mini-Neptunes is a major unanswered question in planet
formation. Unlike Earth, whose atmosphere contains its total mass, a
large fraction of close-in planets have significant gaseous envelopes,
containing or more of their total mass. It has been proposed that
these close-in planets formed in situ either by delivery of
of rocky material to the inner disc, or in a disc enhanced relative to the
MMSN. In both cases, final assembly of the planets occurs by giant impacts
(GIs). Here we test the viability of these scenarios. We show that atmospheres
accreted by isolation masses are small ( the core mass) and
that atmospheric mass-loss during GIs is significant, with typical post-GI
atmospheres that are the core mass. Such values are
consistent with terrestrial planet atmospheres but more than an order of
magnitude below atmospheric masses of inferred for many close-in
exoplanets. In the most optimistic scenario with no core luminosity, post-GI
envelope accretion from a depleted gas disc yields atmospheric masses that are
several per cent the core mass. If the gravitational potential energy due to
the last mass doubling of the planet by GIs is released over the disc
dissipation time-scale as core luminosity, then envelope masses are reduced by
about an order of magnitude. Finally we show that radial drift time-scales due
to gas drag for many isolation masses are shorter than typical disc lifetimes.
Given these challenges, we conclude that most observed close-in planets with
envelopes larger than several per cent likely formed at larger separations from
their host stars.Comment: 10 pages, 10 figures. Abstract abridged for submission. Fixed
typographical error in Eq. 6 exponen
Generation of transgenic human embryonic stem cell line BJNhem20–OCIAD1-OV
Ovarian Carcinoma Immuno-reactive Antigen domain containing protein 1 (OCIAD1) was overexpressed in BJNhem20 human embryonic stem cell line (hESC) using plasmid transfection, followed by stable cell line generation. The construct pCAG-OCIAD1 was introduced into hESCs by microporation
Optimization of Spot Welding of An Assembly Like B-pillar of a Car For Minimum Distortion, By Sequencing Technique
The aim of this paper is to achieve optimisation of spot welding sequence to minimise the distortion of a sheet metal assembly. The distortion of the assembly involving number of spot welds is different for different sequences of welding The assembly consists of sheet metal components which are joined by using various welding sequence schemes. The components are manufactured in quantity and welding with various sequences. After welding the distortions in an assembly due to welding sequence change are worked out and compaired. The sequence with minimum distortion is suggested a solution for the quality manufacturing with minimum distortion induced in it
Expression of conserved signalling pathway genes during spontaneous vascular differentiation of R1 embryonic stem cells and in Py-4-1 endothelial cells
Embryonic stem (ES) cells are an invaluable model for identifying subtle phenotypes as well as severe outcomes of perturbing gene function that may otherwise result in lethality. However, though ES cells of different origins are regarded as equally pluripotent, their in vitro differentiation potential varies, suggesting that their response to developmental signals is different. The R1 cell line is widely used for gene manipulation due to its good growth characteristics and highly efficient germline transmission. Hence, we analysed the expression of Notch, Wnt and Sonic Hedgehog (Shh) pathway genes during differentiation of R1 cells into early vascular lineages. Notch-, Wnt- and Shh-mediated signalling is important during embryonic development. Regulation of gene expression through these signalling molecules is a frequently used theme, resulting in context-dependent outcomes during development.
Perturbing these pathways can result in severe and possibly lethal developmental phenotypes often due to primary cardiovascular defects. We report that during early spontaneous differentiation of R1 cells, Notch-1 and the Wnt target Brachyury are active whereas the Shh receptor is not detected. This expression pattern is similar to that seen in a mouse endothelial cell line. This temporal study of expression of genes representative of all three pathways in ES cell differentiation will aid in further analysis of cell signalling during vascular development
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