<saponifiable and nonsaponifiable soxlet and cold solvent extracts of a number of soils, recent sediment cores from the pacific ocean, and the orgueil carbonaceous meteorite< semiannual progress report, nov. 1964 - may 1965

Saponifiable and nonsaponifiable soxlet and cold solvent extracts of soil, carbonaceous meteorite, and sedimentary rocks studied by thin layer chromatography and spectroscop

A review of evidence for biological material in meteorites

Carbonaceous chondrite - mineral and inorganic chemical composition and biological material in meteorite

Priorities and Preconditions for Successful Investment in Smallholder Agriculture in Sub-Saharan Africa

In the past couple of years, there has been resurgence in interest in smallholder agriculture as a potential driver for growth and poverty reduction in Sub-Saharan Africa. However, there remains considerable skepticism as to whether public investment in smallholder agriculture will lead to the desired growth and poverty reduction, given a general pessimism about "absorptive capacity" for (public) investment in Africa, the perception of failure of past agricultural investment and the observation that current conditions are unconducive to agricultural growth in Africa. This paper combines experiences of two UK-based NGOs dedicated to promoting smallholder agriculture and strengthening rural livelihoods in Africa with insights from academic literature on African agriculture and rural markets to set out an agenda for investment in smallholder agriculture in Africa. It identifies priorities for public investment, but also key issues related to "absorptive capacity" that need to be addressed if such investment is to succeed in generating agricultural growth and poverty reduction. Particular emphasis is placed on: a) investment in human and organisational capacity of smallholder farmers; b) investment in coordinated service provision to equip producers to respond to evolving market opportunities; c) the process of developing and implementing credible agricultural development strategies at both national and local level, and; d) reform of Ministries of Agriculture to support this process.International Development,

Effects of some glycosidases and of periodate on the activity of the glycoprotein NAD(P)ase

Effects of glycosidases and periodate on glycoprotein NAD(P)as

Hydrologic Transport of Dissolved Inorganic Carbon and Its Control on Chemical Weathering

Chemical weathering is one of the major processes interacting with climate and tectonics to form clays, supply nutrients to soil microorganisms and plants, and sequester atmospheric CO2. Hydrology and dissolution kinetics have been emphasized as factors controlling chemical weathering rates. However, the interaction between hydrology and transport of dissolved inorganic carbon (DIC) in controlling weathering has received less attention. In this paper, we present an analytical model that couples subsurface water and chemical molar balance equations to analyze the roles of hydrology and DIC transport on chemical weathering. The balance equations form a dynamical system that fully determines the dynamics of the weathering zone chemistry as forced by the transport of DIC. The model is formulated specifically for the silicate mineral albite, but it can be extended to other minerals, and is studied as a function of percolation rate and water transit time. Three weathering regimes are elucidated. For very small or large values of transit time, the weathering is limited by reaction kinetics or transport, respectively. For intermediate values, the system is transport controlled and is sensitive to transit time. We apply the model to a series of watersheds for which we estimate transit times and identify the type of weathering regime. The results suggest that hydrologic transport of DIC may be as important as reaction kinetics and dilution in determining chemical weathering rates

Improvements in Mass Spectrometers for the Measurement of Small Differences in Isotope Abundance Ratios

A Nier-type mass spectrometer and its associated electronic units have been constructed for the purpose of measuring small variations in the abundances of oxygen of mass 18 and of carbon of mass 13 in carbon dioxide, and of oxygen of mass 18 in oxygen gas, to an accuracy of ±0.01 percent of the abundance of these isotopes.The electronic units of the necessary stability for this degree of accuracy are described. A gas feed system is described which permits fast alternate introduction of the sample of gas to be analyzed and a standard gas into the mass spectrometer. All measurements of the variation in the abundance of the oxygen and carbon isotopes are made with reference to a standard

The Muonium Atom as a Probe of Physics beyond the Standard Model

The observed interactions between particles are not fully explained in the successful theoretical description of the standard model to date. Due to the close confinement of the bound state muonium ($M = \mu^+ e^-$) can be used as an ideal probe of quantum electrodynamics and weak interaction and also for a search for additional interactions between leptons. Of special interest is the lepton number violating process of sponteanous conversion of muonium to antimuonium.Comment: 15 pages,6 figure