Morpho-meiotic study in Mentha longifolia from cold desert regions of Lahaul-Spiti and adjoining areas of Himachal Pradesh (India)

A morpho-meiotic study of wild Mentha longifolia (L.) L. (Lamiaceae) is presented from the nine populations (Kukumsari, Zero-point, Kishori, Tosh, Kasol, Key, Tiling, Mudh and Darcha) in and around the cold desert regions of Lahaul-Spiti of Himachal Pradesh. Present work is needful effort to fill the gap of morpho-meiotic (morphological and cytological) knowledge in M. longifolia growing in high altitude regions. Meiotic study revealed the different chromosome counts in these populations as n = 12, n = 12 + 0-3B and n = 9. Presence of B-chromosome in the species is reported for the first time from the study area and it reflects inter-population variation in five important descriptors (such as a nature of whole plant, stem, leaves, inflorescences and pollen) with 17 sub-descriptor states and occurrence of B-chromosomes. Present study reflects the existence of M. longifolia at diploid (2x) level based on base numbers x = 12 and x = 9

Arbuscular Mycorrhiza-Associated Rhizobacteria and Biocontrol of Soilborne Phytopathogens

The mutualistic symbiosis of most land plants with arbuscular mycorrhizal (AM) fungi has been shown to favor mineral and water nutrition and to increase resistance to abiotic and biotic stresses. The main mechanisms involved in the control of the disease symptoms and intraradical proliferation of soilborne phytopathogens are due to root colonization with AM fungi. The role of the rhizobacteria is shown to be specifically associated with extraradical network of the AM and mycorrhizosphere. The mycorrhizosphere can form a favorable environment for microorganisms which have potentiality to act antagonistic to pathogen abundance. It makes an additional advantage in identifying rhizobacteria from AM fungi structures or mycorrhizosphere, which often lead to the isolation of organisms having strong properties of antagonism on various soilborne pathogens. The ability of AM fungi to control soilborne diseases is mainly related to their capacity to stimulate the establishment of rhizobacteria against the favorable environment of pathogen within the mycorrhizosphere prior to the root infection. Recent advancement in scientific research has provided more clear picture in understanding the mechanisms involved in AM fungi/rhizobacteria interactions. Herein, this chapter includes the mechanisms of the AM fungi-mediated biocontrol, interactions between AM-associated bacteria and AM fungus extraradical network, AM-associated bacteria and biocontrol activities and unfavorable zone to pathogen development: the mycorrhizosphere

Plutajuće mikrosfere cimetidina: Priprava, karakterizacija i in vitro evaluacija

The present study involves preparation and evaluation of floating microspheres with cimetidine as model drug for prolongation of gastric residence time. The microspheres were prepared by the solvent evaporation method using polymers hydroxypropylmethyl cellulose and ethyl cellulose. The shape and surface morphology of prepared microspheres were characterized by optical and scanning electron microscopy, respectively. In vitro drug release studies were performed and drug release kinetics was evaluated using the linear regression method. Effects of stirring rate during preparation, polymer concentration, solvent composition and dissolution medium on the size of microspheres and drug release were also observed. The prepared microspheres exhibited prolonged drug release (~ 8 h) and remained buoyant for > 10 h. The mean particle size increased and drug release rate increased at higher polymer concentration. In vitro studies demonstrated diffusion-controlled drug release from the microspheres. No significant effect of the stirring rate during preparation on drug release was observed.U radu je opisana priprava i evaluacija plutajućih mikrosfera za produljeno zadržavanje u želucu. Cimetidin je izabran kao model lijeka. Mikrosfere su pripravljene metodom uparavanja otapala koristeći hidroksipropilmetilcelulozu i etilcelulozu. Optičkom, odnosno pretražnom elektronskom mikroskopijom karakterizirani su oblik i morfologija površine mikrosfera. Kinetika oslobađanja ljekovite tvari in vitro evaluirana je pomoću metode linearne regresije. Proučavan je utjecaj brzine miješanja tijekom priprave, koncentracije polimera, vrste otapala i medija za oslobađanje na veličinu mikrosfera, odnosno oslobađanje lijeka. Iz pripravljenih mikrosfera lijek se produljeno oslobađa (~ 8 h), a mikrosfere ostaju plutati više od 10 h. Veće mikrosfere dobivene su upotrebom veće koncentracije polimera. Pokusi in vitro ukazuju da je oslobađanje ljekovite tvari studies kontrolirano difuzijom. Brzina miješanja tijekom priprave nema utjecaja na oslobađanje ljekovite tvari

Study of Microstrip filters

Volume 2 Issue 1 (January 2014

Investigations on Structural, Mechanical, and Dielectric Properties of PVDF/Ceramic Composites

Polymer ceramic composites are widely used for embedded capacitor application. In the present work PVDF has been used as a matrix and CCTO and LaCCTO have been used as reinforcement. Extrusion process has been used for the synthesis of composites. X-ray diffraction (XRD) patterns confirm the formation of single phase CCTO, and LaCCTO in its pure as well as composite state. It is found that La doping in CCTO considerably increases the dielectric constant and reduces the dielectric loss. A similar trend is observed in the composites with the increasing content of CCTO and LaCCTO

Partitioning Apomixis Components to Understand and Utilize Gametophytic Apomixis

Apomixis is a method of reproduction to generate clonal seeds and offers tremendous potential to fix heterozygosity and hybrid vigor. The process of apomictic seed development is complex and comprises three distinct components, viz., apomeiosis (leading to formation of unreduced egg cell), parthenogenesis (development of embryo without fertilization) and functional endosperm development. Recently, in many crops, these three components are reported to be uncoupled leading to their partitioning. This review provides insight into the recent status of our understanding surrounding partitioning apomixis components in gametophytic apomictic plants and research avenues that it offers to help understand the biology of apomixis. Possible consequences leading to diversity in seed developmental pathways, resources to understand apomixis, inheritance and identification of candidate gene(s) for partitioned components, as well as contribution towards creation of variability are all discussed. The potential of Panicum maximum, an aposporous crop, is also discussed as a model crop to study partitioning principle and effects. Modifications in cytogenetic status, as well as endosperm imprinting effects arising due to partitioning effects, opens up new opportunities to understand and utilize apomixis components, especially towards synthesizing apomixis in crops

Rehabilitation of ocular defect: A modified technique to produce corneal prominence

Esthetics is a vital social concern. The loss of any part of the body can be an extremely discouraging occasion in a person's life. Loss of an eye because of tumors, congenital abnormalities, and trauma is one such troublesome situation. Eye prosthesis boosts the morale and makes the life socially acceptable. A correctly placed ocular prosthesis should reestablish the normal opening of the eye, support the eyelids, reestablish a degree of movement, and be satisfactorily held and esthetically satisfying. A customized acrylic eye fulfills all these requirements. In the current article, a new and economic technique was used to duplicate corneal prominence using a clear acrylic shell. The characterization was further done to give a life-like appearance to the eye prostheses

Investigations on Structural, Mechanical, and Dielectric Properties of PVDF/Ceramic Composites

Polymer ceramic composites are widely used for embedded capacitor application. In the present work PVDF has been used as a matrix and CCTO and LaCCTO have been used as reinforcement. Extrusion process has been used for the synthesis of composites. X-ray diffraction (XRD) patterns confirm the formation of single phase CCTO, and LaCCTO in its pure as well as composite state. It is found that La doping in CCTO considerably increases the dielectric constant and reduces the dielectric loss. A similar trend is observed in the composites with the increasing content of CCTO and LaCCTO