<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 POLICY AGENDA FOR PRO POOR AGRICULTURAL GROWTH

Economic growth has been low and the incidence and numbers of poor people remain very high in some parts of the world, notably in sub Saharan Africa and some parts of South Asia. Projections for poverty reduction suggest that these regions are likely to continue to hold very large numbers of very poor rural people in the foreseeable future. Theoretical arguments and empirical evidence suggest that in poor agrarian economies both the processes of structural change within national economies and micro-economic relations within rural economies give agriculture (and particularly intensive cereal based growth) a pre-eminent and unique role in economic development and in poverty reduction. However, reliance on pro-poor agricultural growth as the main weapon against rural poverty today faces more difficult challenges than those faced in the green revolution areas in the latter part of the 20th century, due to a number of features that together increase risk and uncertainty and raise costs and/or lower returns to agricultural investment. Many of these difficulties are endogenous to today's poor rural areas, others result from broader processes of global change, but it is argued that some are the direct result of policies supporting liberalisation and withdrawal of the state. A review of the green revolutions of the 20th century suggests that state interventions in agricultural markets were widely used and important in supporting sometimes short periods of critical market and technological development in the process of rural growth. Unfortunately the benefits of such interventions have been overlooked as a result of their very evident inefficiency and high costs, without a clear understanding of their institutional benefits. Policy and research implications of this analysis are discussed.Food Security and Poverty, International Development,

The Cognitive Use of Prior Knowledge in Design Cognition: The Role of Types and Precedents in Architectural Design

This paper examines the cognitive use of prior knowledge in the design and evaluates the role of types and precedents in architectural design and education from a cognitive perspective. The previous research on design cognition shows that the amount of prior knowledge possessed by the designer plays a fundamental role in the production and quality of the creative outcome. This paper examines this correlation between the cognitive concept of cultural schemas with the architectural concept of types and investigates the cognitive role of types and precedents within architectural design and education in the light of the cognitive literature. With such an attempt, the research conducts an interdisciplinary theoretical inquiry that respectively studies the role of prior knowledge in design cognition, the concept of cognitive-cultural schemas, the concept of type and its relationship with cultural schemas, and the cognitive role of types and precedents in architectural design and education. In conclusion, this study proposes that types function identically as cultural schemas at the cognitive level and types and precedents have a generative value for architectural design, by virtue of the fact that they exist as the initial cognitive schemas that are employed at the beginning of the design process

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,

Space bandwidth product of conventional Fourier Transforming Systems

Cataloged from PDF version of article.It is shown that the space-bandwidth product of conventional "2f" Fourier transforming configurations can be increased without bound by increasing the diameter D and focal length fof the lens simultaneously to Docf 3/4. This results in spacebandwidth product growth ocf ~/2 and accompanying system linear extent growth ocf ~/4. These are derived by considering the validity of the Fresnel approximation, the thin lens approximation, and the effects of aberrations

Scaling of diffractive and refractive lenses for optical computing and interconnections

Cataloged from PDF version of article.We discuss both numerically and analytically how the space-bandwidth product and the information density of lenses scale as functions of their diameter and f-number over many orders of magnitude. This information may be useful for the design of optical computing and interconnection systems. For diffractive lenses, cost is defined as the number of resolution elements the lithographic production system must have; the relationship of this quantity to the space-bandwidth product and information density is also given

Orbital effects of spatial variations of fundamental coupling constants

We deal with the effects induced on the orbit of a test particle revolving around a central body by putative spatial variations of fundamental coupling constants $\zeta$. In particular, we assume a dipole gradient for \zeta(\bds r)/\bar{\zeta} along a generic direction \bds{\hat{k}} in space. We analytically work out the long-term variations of all the six standard Keplerian orbital elements parameterizing the orbit of a test particle in a gravitationally bound two-body system. It turns out that, apart from the semi-major axis $a$, the eccentricity $e$, the inclination $I$, the longitude of the ascending node $\Omega$, the longitude of pericenter $\pi$ and the mean anomaly $\mathcal{M}$ undergo non-zero long-term changes. By using the usual decomposition along the radial ($R$), transverse ($T$) and normal ($N$) directions, we also analytically work out the long-term changes $\Delta R,\Delta T,\Delta N$ and $\Delta v_R,\Delta v_T,\Delta v_N$ experienced by the position and the velocity vectors \bds r and \bds v of the test particle. It turns out that, apart from $\Delta N$, all the other five shifts do not vanish over one full orbital revolution. In the calculation we do not use \textit{a-priori} simplifying assumptions concerning $e$ and $I$. Thus, our results are valid for a generic orbital geometry; moreover, they hold for any gradient direction (abridged).Comment: Latex2e, 20 pages, 1 figure, 7 tables. Version accepted by Monthly Notices of the Royal Astronomical Society (MNRAS). Error in the caption of Table 5 corrected. References update

Learned holographic light transport: Invited

Computer-generated holography algorithms often fall short in matching simulations with results from a physical holographic display.Our work addresses this mismatch by learning the holographic light transport in holographic displays. Using a camera and a holographic display, we capture the image reconstructions of optimized holograms that rely on ideal simulations to generate a dataset. Inspired by the ideal simulations, we learn a complex-valued convolution kernel that can propagate given holograms to captured photographs in our dataset. Our method can dramatically improve simulation accuracy and image quality in holographic displays while paving the way for physically informed learning approaches