2,764 research outputs found

    Induced polyploidization in Brassica campestris L. (Brassicaceae)

    No full text
    Present experimental design has been made up to obtain crop with higher ploidy level via synthetic polyploidization. Since ploidy manipulation is generally associated with the obtainment of some increased enviable traits of the crop and also provides them greater adaptability to unfavorable or harsh circumstances as compared to its diploids counterparts. Thus, herein present research autotetraploids of Brassica campestris L. have been lucratively achieved by the application of colchicine. Two methods of treatment were utilized i.e. seed treatment and seedling treatment. No polyploidy could be obtained through seed treatment while seedling treatment responded well towards polyploidy. However, the status of autotetraploidy has been confirmed by cytomorphological investigations of treated plants as against its diploids counterparts. For the purpose, morphological parameters such as increased stomata size, pollen diameter, flower size, reproductive organs whereas reduction in plant height, leaf length, leaf breadth, stomata frequency, number of flowers/inflorescence etc. were appraised. Further, cytological observations were made that had clearly revealed the doubling of genome in the autotetraploids as compared to diploids. Meanwhile, pollen fertility and size of pollen grains were evaluated as well.Разработана экспериментальная схема получения сельскохозяйственных культур с более высокой плодиностью путем искусственной полиплоидизации. Изменение плоидности обычно связано с приобретением некоторых важных признаков у таких культур, а также обеспечивает их более высокую приспособляемость к неблагоприятным или суровым условиям внешней среды по сравнению с диплоидными аналогами. В настоящем исследовании представлено успешное получение автотетраплоидов Brassica campestris L. с помощью колхицина. Для этого применяли два метода обработки – семян и проростков. Никакой полиплоидии не обнаружено при обработке семян, тогда как после обработки проростков полиплоиды были получены. С помощью цитоморфологических исследований подтверждено наличие автотетраплоидности у обработанных растений по сравнению с их диплоидными аналогами. Для этого оценивали такие морфологические параметры, как увеличенные размер устьиц, диаметр пыльцы, размер цветка, репродуктивные органы, а также уменьшенные высота растений, длина листа, ширина листа, частота устьиц, число цветков и соцветий. Более того, в результате цитологических исследований четко установлено удвоение генома у автотетраплоидов по сравнению с диплоидами. Наряду с этим в работе оценивали фертильность пыльцы и величину пыльцевых зерен

    Uterine cavity evaluation in infertile patients with transvaginal sonography, saline infusion sonography and hysteroscopy

    Get PDF
    Background: To compare diagnostic accuracy of Transvaginal sonography (TVS), Saline infusion sonography (SIS) and hysteroscopy in infertile women.Methods: In a prospective study, 250 women with complaint of infertility underwent TVS and SIS. Diagnostic and operative hysteroscopy under general anaesthesia was then performed.Results: Hysteroscopy with directed biopsy was considered as the gold standard. Endometrial polyp (n=25, 10%), submucosal fibroid (n=12, 4.8%), suspected intrauterine adhesions (n=4, 1.6%) and congenital uterine anamoly (n=2, 0.8%) were detected with TVS. In the evaluation with SIS results Endometrial polyp (n=34, 13.6%), submucosal fibroid (n=20, 18.1%), suspected intrauterine adhesions (n=5, 2%) and congenital uterine anamoly (3, 1.2%). Hysteroscopy results detected Endometrial polyp (n=32, 12.8%), submucosal fibroid (n=19, 7.6%), suspected intrauterine adhesions (n=8, 3.2%) and congenital uterine anamoly (n=5, 2%).Conclusions: TVS is the primary investigative method for evaluating every infertile couple by means of uterine cavity and ovaries. Hysteroscopy is superior to SIS in diagnosis of intracavitatory abnormalities. However SIS has the advantage of being noninvasive, cheap, affordable, short duration and accurate method for uterine cavity evaluation

    Appearance of the central singularity in spherical collapse

    Get PDF
    We analyze here the structure of non-radial nonspacelike geodesics terminating in the past at a naked singularity formed as the end state of inhomogeneous dust collapse. The spectrum of outgoing nonspacelike null geodesics is examined analytically. The local and global visibility of the singularity is also examined by integrating numerically the null geodesics equations. The possible implications of existence of such families towards the appearance of the star in late stages of gravitational collapse are considered. It is seen that the outgoing non-radial geodesics give an appearance to the naked central singularity as that of an expanding ball whose radius reaches a maximum before the star goes within its apparent horizon. The radiated energy (along the null geodesics) is shown to decay very sharply in the neighbourhood of the singularity. Thus the total energy escaping via non-radial null geodesics from the naked central singularity vanishes in the scenario considered here.Comment: 25 pages, 6 figure

    Formation of a rotating jet during the filament eruption on 10-11 April 2013

    Full text link
    We analyze multi-wavelength and multi-viewpoint observations of a helically twisted plasma jet formed during a confined filament eruption on 10-11 April 2013. Given a rather large scale event with its high spatial and temporal resolution observations, it allows us to clearly understand some new physical details about the formation and triggering mechanism of twisting jet. We identify a pre-existing flux rope associated with a sinistral filament, which was observed several days before the event. The confined eruption of the filament within a null point topology, also known as an Eiffel tower (or inverted-Y) magnetic field configuration results in the formation of a twisted jet after the magnetic reconnection near a null point. The sign of helicity in the jet is found to be the same as that of the sign of helicity in the filament. Untwisting motion of the reconnected magnetic field lines gives rise to the accelerating plasma along the jet axis. The event clearly shows the twist injection from the pre-eruptive magnetic field to the jet.Comment: 14 pages, 12 figures, to appear in MNRA

    A conceptual review of Basti (Urinary Bladder) as Pranayatana

    Get PDF
    Ayurveda is a system of medicine, which gives the way of perfect living with nature. It is a science which is on the rise as a result of various discussion and researches from ancient time onwards. Its gives equal importance to preventive and curative aspects of disease. As we know the diagnosis of any disease is very important before treatment, similarly the knowledge of Rachana Sharir is also important before diagnosis. The word Pranayatana is formed by two words – Prana + Ayatana. Here Ayatana means residing place (Ashraya Sthana) and Prana means live attribute (life). So, the Sthana which gives seat for Prana is called as Pranayatana. Basti is one such Pranayatana mentioned in Charaka Samhita. It has been given much importance that it has been mentioned both in the context of Dasha Pranayatana and Marma. In this article, an attempt is made to understand and review Basti in the context of Dasha Pranayatanas

    The final fate of spherical inhomogeneous dust collapse II: Initial data and causal structure of singularity

    Full text link
    Further to results in [9], pointing out the role of initial density and velocity distributions towards determining the final outcome of spherical dust collapse, the causal structure of singularity is examined here in terms of evolution of the apparent horizon. We also bring out several related features which throw some useful light towards understanding the nature of this singularity, including the behaviour of geodesic families coming out and some aspects related to the stability of singularity.Comment: Latex file, uses epsf.sty, 15 pages and 3 eps figures. Paragraph on role of smooth functions rewritten. Four references added. To appear in Classical & Quantum Gravit

    Compact thermally tunable silicon racetrack modulators based on an asymmetric waveguide

    Get PDF
    A compact wavelength-tunable 10-Gb/s silicon racetrack modulator with integrated thermo-optic heater is demonstrated by using a waveguide with an asymmetric cross section, combining the compact footprint of microdisk modulators with the design simplicity of regular racetrack or ring modulators. The outer perimeter of the asymmetric racetrack modulator is fully etched to maximize optical confinement, and the inner waveguide edge is shallowly etched to maintain an electrically conductive path to the embedded p-n diode and to control the propagation of the asymmetric optical mode and its coupling to the bus waveguide. The resistive heating elements based on highly doped Si strips are implemented at the outer edge of the modulator for thermo-optic control. The asymmetric modulators can be fabricated along with Si wire waveguides and shallowly etched fiber-grating couplers using a simple process flow involving just two Si-patterning steps. Devices with a bending radius of 10 mu m and a novel "T"-shaped p-n diode layout have been fabricated, and exhibit electro-optic modulation and heater efficiencies of 28 pm/V and 42 pm/mW, respectively. At 10 Gb/s, a stable extinction ratio of 10 dB is demonstrated from a 2V(pp) drive swing, which can be maintained over a wavelength range of 4.6 nm by thermally tuning the modulator. This is equivalent with a temperature variation of about 62 degrees C

    Initial data and the end state of spherically symmetric gravitational collapse

    Get PDF
    Generalizing earlier results on the initial data and the final fate of dust collapse, we study here the relevance of the initial state of a spherically symmetric matter cloud towards determining its end state in the course of a continuing gravitational collapse. It is shown that given an arbitrary regular distribution of matter at the initial epoch, there always exists an evolution from this initial data which would result either in a black hole or a naked singularity depending on the allowed choice of free functions available in the solution. It follows that given any initial density and pressure profiles for the cloud, there is a non-zero measure set of configurations leading either to black holes or naked singularities, subject to the usual energy conditions ensuring the positivity of energy density. We also characterize here wide new families of black hole solutions resulting from spherically symmetric collapse without requiring the cosmic censorship assumption.Comment: Ordinary Tex file, 31 pages no figure

    Viscoelastic Properties of Dynamically Asymmetric Binary Fluids Under Shear Flow

    Full text link
    We study theoretically the viscoelastic properties of sheared binary fluids that have strong dynamical asymmetry between the two components. The dynamical asymmetry arises due to asymmetry between the viscoelastic stresses, particularly the bulk stress. Our calculations are based on the two-fluid model that incorporates the asymmetric stress distribution. We simulate the phase separation process under an externally imposed shear and compare the asymmetric case with the usual phase separation under a shear flow without viscoelastic effects. We also simulate the behavior of phase separated stable morphologies under applied shear and compute the stress relaxation.Comment: 10 pages text, 9 figure
    corecore