813 research outputs found
Gene transfer technologies in plants: Roles in improving crops
Gene is a segment of nucleic acid that encodes a functional protein or RNA and is the unit of inheritance. The principle objective of plant biotechnology is to create new varieties of cultivated plants by manipulating DNA molecule. Plant transformation technology has become a versatile platform for cultivar improvement as well as for analysis of gene function in plants. This article discuses and summarizes important work in the literature regarding the gene transfer technologies in plants. The main techniques focused in this article are gene transfer by Agrobacterium tumefaciens, microprojectile bombardment, electroporation of protoplast, polyethylene glycol method,ĂâĂ microinjection, silicon carbide mediated transformation, liposome mediated gene transfer and sonication assistedĂâĂ Agrobacterium-mediated transformation. Moreover the application of gene transfer technologies related to the improvement of crops was also focused. This article will help the reader to have an idea on gene transfer technologies and also to the researcher working on plant genetic engineering
Immunomodulatory activity of Terminalia chebula against Salmonella typhimurium in mice
Typhoid is a world wide problem today due to the emergence of multidrug resistance Salmonella typhi and limited scope of vaccine against this disease. As the plant product has little side effects and is the source of many compounds having wide range of biological activities, diverted the author to study the protective role of Terminalia chebula, against Salmonella typhimurium. The author has already reported the protective effect of aqueous extract of the fruits of this plant against S. typhimurium in vitro as well as in vivo and also the antioxidant activity against theseĂâĂ bacteria. In this study the same extract was evaluated for its immunomodulatory activityĂâĂ against S. typhimurium in vivo. Animals pretreated with the same extract at a dose 500 mg/kg body wt orally showed an increase in WBC count by 3x103/cu mm and lymphocyte count by 4 % as compared to saline treated control challenged with 50000 colony forming unit of S.ĂâĂ typhimurium. The drug showed the proliferation of lymphocyte by 102% and increase in food pad thickness by 28.87% as compared to infected control in delayed type of hypersensitivity test. Thus the drugs showed its protective effect through its immunomodulatory activity in mice and can be used in typhoid
Protective Effect of Emblica officinalis Against S.typhimurium Through its Antioxidant Activity
Typhoid is a major public health problem caused by Salmonella typhi. SalmonellaĂÂ typhimurium (S. typhimurium) causes an invasive disease in mice that has similarity with human typhoid. The antibiotics used got resistant to the bacteria and has side effects while vaccine developed has little scope against this disease. In this study antioxidant activity of fruits of Emblica officinalis was explored against the oxidative stress generated by S. typhimurium in mice. Animals pretreated with EO500 for a period of 30 days followed by challenged with 50000 (CFU) of S. typhimurium exhibit a decrease in Xanthine oxidase activity by 36% and increase in glutathione peroxidase and glutathione reductase activity by 37% and 38% respectively as compared to mice infected with same doses of S. typhimurium. ĂÂ The study confirmed the lowering of oxidative stress in mice by this drug and can be used in typhoid
Gene transfer technologies leading to transgenic animals
Gene that is introduced into the cell from an external source is called transgene. A fertile animal that carries an introduced gene (s) in its germ line is called transgenic animal. The introduction of gene (s) into animl cells that leads to the transmission of the input transgene to successive generation is called transgenesis. This article discuses and summarizes important work in the literature regarding the gene transfer technologies leading to transgenic animals. The main techniques focused in this article are DNA transfer to anmals by microinjection, biolistics and electroporation. Much stress has been given to embryonic stem cell technology, sperm-mediated gene transfer, intracytoplasmic sperm injection (ICSI), liposome/DNA delivery method, gene transfer by retrovirus and nuclear transfer method.ĂâĂ Models for transgenic animals were also focussed. The author also reviewed the transgenic animals as bioreactors, pharmaceutical proteins derived from these animals and transgenic expression of immunoglobulin. This article will be a valuable source of information for the researcher who are starting their career in transgenic animals
Polymers at Interfaces: Biological and Non-biological Applications
Polymer is a long chain macromolecule comprising of several monomers. The interface is the dividing region between two phases. In this article the authors describe about the polymers at interfaces. The interfacial behaviour of polymers is an area of active research and holds immense potential for technological advances. Polymers can adhere to an interface either by physisorption or by chemical grafting. This article discusses and summarizes important work in the literature regarding the various technological applications of polymers at interfaces. They are explored cutting across disciplines and emphasizing the versatility of the interfacial behavior phenomenon. The fields of colloidal stabilization and bridging flocculation, detergency and biomedical applications are explored and latest developments in these areas are focused. ĂâĂ The emphasis is on practical issues rather than on the theoretical ones, as there are quite a few review articles available on the latter. This article will be a valuable source of information for the researchers who are starting their career in polymers related to biotechnology and chemical engineering
Modelling of the effect of scale on the compressibility parameters of fine-grained soils
The effect of sample scale represents a challenge when obtaining engineering parameters in the laboratory compared to those obtained in the field. This study aimed at contributing to existing knowledge numerically using the finite element software PLAXIS 2D. The investigations were analysed in terms of height scale (HS) and diameter scale (DS) through a series of laboratory tests. Its effect on compressibility parameters such as coefficient of consolidation (cv) was noted experimentally and showed that the sample scale greatly influences soil parameters most particularly at DS. The soil behaviour was found to be dependent on both DS and HS with a correlation factor of 0.650 and 0.062, respectively. The experimental data were validated in PLAXIS and a new proposed model was developed in PLAXIS 2D under the DS. The new proposed model developed was found to show no significant difference with the laboratory data
New early Eocene tapiromorph perissodactyls from the Ghazij Formation of Pakistan, with implications for mammalian biochronology in Asia
Early Eocene mammals from Indo-Pakistan have only recently come under study. Here we describe the first tapiromorph perissodactyls from the subcontinent. Gandheralophus minor n. gen. and n. sp. and G. robustus n. sp. are two species of Isectolophidae differing in size and in reduction of the anterior dentition. Gandheralophus is probably derived from a primitive isectolophid such as Orientolophus hengdongensis from the earliest Eocene of China, and may be part of a South Asian lineage that also contains Karagalax from the middle Eocene of Pakistan. Two specimens are referred to a new, unnamed species of Lophialetidae. Finally, a highly diagnostic M3 and a molar fragment are described as the new eomoropid chalicothere Litolophus ghazijensis sp. nov. The perissodactyls described here, in contrast to most other mammalian groups published from the early Eocene of Indo-Pakistan, are most closely related to forms known from East and Central Asia. Tapiromorpha are diverse and biochronologically important in the Eocene there and our results allow the first biochronological correlation between early Eocene mammal faunas in Indo-Pakistan and the rest of Asia. We suggest that the upper Ghazij Formation of Pakistan is best correlated with the middle or late part of the Bumbanian Asian Land-Mammal Age, while the Kuldana and Subathu Formations of Pakistan and India are best correlated with the Arshantan Asian Land-Mammal Age
Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV
Results are presented from a search for a W' boson using a dataset
corresponding to 5.0 inverse femtobarns of integrated luminosity collected
during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV.
The W' boson is modeled as a heavy W boson, but different scenarios for the
couplings to fermions are considered, involving both left-handed and
right-handed chiral projections of the fermions, as well as an arbitrary
mixture of the two. The search is performed in the decay channel W' to t b,
leading to a final state signature with a single lepton (e, mu), missing
transverse energy, and jets, at least one of which is tagged as a b-jet. A W'
boson that couples to fermions with the same coupling constant as the W, but to
the right-handed rather than left-handed chiral projections, is excluded for
masses below 1.85 TeV at the 95% confidence level. For the first time using LHC
data, constraints on the W' gauge coupling for a set of left- and right-handed
coupling combinations have been placed. These results represent a significant
improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe
Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV
A search for a Higgs boson decaying into two photons is described. The
analysis is performed using a dataset recorded by the CMS experiment at the LHC
from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an
integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross
section of the standard model Higgs boson decaying to two photons. The expected
exclusion limit at 95% confidence level is between 1.4 and 2.4 times the
standard model cross section in the mass range between 110 and 150 GeV. The
analysis of the data excludes, at 95% confidence level, the standard model
Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The
largest excess of events above the expected standard model background is
observed for a Higgs boson mass hypothesis of 124 GeV with a local significance
of 3.1 sigma. The global significance of observing an excess with a local
significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is
estimated to be 1.8 sigma. More data are required to ascertain the origin of
this excess.Comment: Submitted to Physics Letters
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