106 research outputs found

    Ricinus communis-linn (castor plant), male contraceptives and reproductive health of women

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    The medicinal use of castor plant is extensive. Castor oil is most commonly used as a laxative, and the leaves and seeds have been used to augment labour, promote lactation and to treat syphilis and leprosy. Its use for contraception is an ancient practice among the Rukuba women of Plateau State in Nigeria, who would chew 2-3 seeds for contraceptive coverage of one year. The acute and chronic spermatogenic effect of the minor seed variety of ricinus communis-linn is hereby reported. Thirty male rats weighing 200–250g were grouped (n = 5) and treated with the n-hexane extract of the seeds, each made up to 1ml with physiological saline, and given as a single dose, intraperitoneally. Control groups had 1 ml physiological saline. Semen was collected 72 h and 6 weeks after treatment and analyzed within one hour of collection. The seed extract suppressed spermatogenesis and sperm motility up to six weeks after treatment. But semen parameters reverted to normal values in the 7 weeks of treatment, showing primary spermatocytes and spermatids in the seminiferous tubules. Our results showed ricinus communis-linn to be a potent but reversible anti-spermatogenic agent with significant anti-motility properties. Moreover, being of plant origin, it is readily available and affordable. We hereby present ricinus communis-linn as a possible male contraceptive agent that can relieve women of their reproductive burden globally.   L'utilisation médicinale de la plante de ricin est étendue. L'huile de ricin est le plus souvent utilisée comme laxatif, et les feuilles et les graines ont été utilisées pour augmenter le travail, favoriser la lactation et traiter la syphilis et la lèpre. Son utilisation pour la contraception est une pratique ancienne chez les femmes Rukuba de l'État du Plateau au Nigeria, qui mâchaient 2-3 graines pour une couverture contraceptive d'un an. L'effet spermatogène aigu et chronique de la variété mineure de graines de ricinus communis-linn est rapporté ici. Trente rats mâles pesant 200 à 250 g ont été regroupés (n = 5) et traités avec l'extrait de n-hexane des graines, chacun complété à 1 ml de sérum physiologique et administré en une seule dose, par voie intrapéritonéale. Les groupes témoins avaient 1 ml de sérum physiologique. Le sperme a été collecté 72 h et 6 semaines après le traitement et analysé dans l'heure suivant le prélèvement. L'extrait de graines a supprimé la spermatogenèse et la motilité des spermatozoïdes jusqu'à six semaines après le traitement. Mais les paramètres du sperme sont revenus à des valeurs normales au cours des 7 semaines de traitement, montrant des spermatocytes et des spermatides primaires dans les tubules séminifères. Nos résultats ont montré que le ricinus communis-linn est un agent anti-spermatogène puissant mais réversible avec des propriétés anti-motilité significatives. De plus, étant d'origine végétale, il est facilement disponible et abordable. Nous présentons ici le ricinus communis-linn comme un agent contraceptif masculin possible qui peut soulager les femmes de leur fardeau reproductif à l'échelle mondiale

    Sensors and Systems for in situ Observations of Marine Carbon Dioxide System Variables

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    Autonomous chemical sensors are required to document the marine carbon dioxide system's evolving response to anthropogenic CO2 inputs, as well as impacts on short- and long-term carbon cycling. Observations will be required over a wide range of spatial and temporal scales, and measurements will likely need to be maintained for decades. Measurable CO2 system variables currently include total dissolved inorganic carbon (DIC), total alkalinity (AT), CO2 fugacity (fCO2), and pH, with comprehensive characterization requiring measurement of at least two variables. These four parameters are amenable to in situ analysis, but sustained deployment remains a challenge. Available methods encompass a broad range of analytical techniques, including potentiometry, spectrophotometry, conductimetry, and mass spectrometry. Instrument capabilities (precision, accuracy, endurance, reliability, etc.) are diverse and will evolve substantially over the time that the marine CO2 system undergoes dramatic changes. Different suites of measurements/parameters will be appropriate for different sampling platforms and measurement objectives

    Measurement of W Polarisation at LEP

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    The three different helicity states of W bosons produced in the reaction e+ e- -> W+ W- -> l nu q q~ at LEP are studied using leptonic and hadronic W decays. Data at centre-of-mass energies \sqrt s = 183-209 GeV are used to measure the polarisation of W bosons, and its dependence on the W boson production angle. The fraction of longitudinally polarised W bosons is measured to be 0.218 \pm 0.027 \pm 0.016 where the first uncertainty is statistical and the second systematic, in agreement with the Standard Model expectation

    Search for Anomalous Couplings in the Higgs Sector at LEP

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    Anomalous couplings of the Higgs boson are searched for through the processes e^+ e^- -> H gamma, e^+ e^- -> e^+ e^- H and e^+ e^- -> HZ. The mass range 70 GeV < m_H < 190 GeV is explored using 602 pb^-1 of integrated luminosity collected with the L3 detector at LEP at centre-of-mass energies sqrt(s)=189-209 GeV. The Higgs decay channels H -> ffbar, H -> gamma gamma, H -> Z\gamma and H -> WW^(*) are considered and no evidence is found for anomalous Higgs production or decay. Limits on the anomalous couplings d, db, Delta(g1z), Delta(kappa_gamma) and xi^2 are derived as well as limits on the H -> gamma gamma and H -> Z gamma decay rates

    Measurement of W Polarisation at LEP

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    The three different helicity states of W bosons produced in the reaction e+ e- -> W+ W- -> l nu q q~ at LEP are studied using leptonic and hadronic W decays. Data at centre-of-mass energies \sqrt s = 183-209 GeV are used to measure the polarisation of W bosons, and its dependence on the W boson production angle. The fraction of longitudinally polarised W bosons is measured to be 0.218 \pm 0.027 \pm 0.016 where the first uncertainty is statistical and the second systematic, in agreement with the Standard Model expectation

    Neutral-Current Four-Fermion Production in e+e- Interactions at LEP

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    Neutral-current four-fermion production, e+e- -> ffff is studied in 0.7/fb of data collected with the L3 detector at LEP at centre-of-mass energies root(s)=183-209GeV. Four final states are considered: qqvv, qqll, llll and llvv, where l denotes either an electron or a muon. Their cross sections are measured and found to agree with the Standard Model predictions. In addition, the e+e- -> Zgamma* -> ffff process is studied and its total cross section at the average centre-of-mass energy 196.6GeV is found to be 0.29 +/- 0.05 +/- 0.03 pb, where the first uncertainty is statistical and the second systematic, in agreement with the Standard Model prediction of 0.22 pb. Finally, the mass spectra of the qqll final states are analysed to search for the possible production of a new neutral heavy particle, for which no evidence is found

    Measurement of Exclusive rho+rho- Production in Mid-Virtuality Two-Photon Interactions and Study of the gamma gamma* -> rho rho Process at LEP

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    Exclusive rho+rho- production in two-photon collisions between a quasi-real photon, gamma, and a mid-virtuality photon, gamma*, is studied with data collected at LEP at centre-of-mass energies root(s)=183-209GeV with a total integrated luminosity of 684.8pb^-1. The cross section of the gamma gamma* -> rho+ rho- process is determined as a function of the photon virtuality, Q^2, and the two-photon centre-of-mass energy, W_gg, in the kinematic region: 0.2GeV^2 < Q^2 <0.85GeV^2 and 1.1GeV < W_gg < 3GeV. These results, together with previous L3 measurements of rho0 rho0 and rho+ rho- production, allow a study of the gamma gamma* -> rho rho process over the Q^2-region 0.2GeV^2 < Q^2 < 30 GeV^2

    Bose-Einstein Correlations of Neutral and Charged Pions in Hadronic Z Decays

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    Bose-Einstein correlations of both neutral and like-sign charged pion pairs are measured in a sample of 2 million hadronic Z decays collected with the L3 detector at LEP. The analysis is performed in the four-momentum difference range 300 MeV < Q < 2 GeV. The radius of the neutral pion source is found to be smaller than that of charged pions. This result is in qualitative agreement with the string fragmentation model

    Z Boson Pair-Production at LEP

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    Events stemming from the pair-production of Z bosons in e^+e^- collisions are studied using 217.4 pb^-1 of data collected with the L3 detector at centre-of-mass energies from 200 GeV up to 209 GeV. The special case of events with b quarks is also investigated. Combining these events with those collected at lower centre-of-mass energies, the Standard Model predictions for the production mechanism are verified. In addition, limits are set on anomalous couplings of neutral gauge bosons and on effects of extra space dimensions

    Measurement of the Running of the Electromagnetic Coupling at Large Momentum-Transfer at LEP

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    The evolution of the electromagnetic coupling, alpha, in the momentum-transfer range 1800GeV^2 < -Q^2 < 21600GeV^2 is studied with about 40000 Bhabha-scattering events collected with the L3 detector at LEP at centre-of-mass energies 189-209GeV. The running of alpha is parametrised as: alpha(Q^2) = alpha_0/(1-C Delta alpha(Q^2)), where alpha_0=\alpha(Q^2=0) is the fine-structure constant and C=1 corresponds to the evolution expected in QED. A fit to the differential cross section of the e+e- ->e+e- process for scattering angles in the range |cos theta|<0.9 excludes the hypothesis of a constant value of alpha, C=0, and validates the QED prediction with the result: C = 1.05 +/- 0.07 +/- 0.14, where the first uncertainty is statistical and the second systematic
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