Evaluation and Impact of Training in the CGIAR

This study was commissioned by the interim Science Council (iSC) to review training within the CGIAR as it contributes to capacity strengthening in the NARS. The purpose of the study was to evaluate the quality and relevance, efficiency and effectiveness terms of intermediate impacts in strengthening of the NARS and, to the extent possible, impacts in the CGIAR’s goals. The study was expected to provide recommendations to help Centers, Donors, the NARS and the System to strengthen and plan their future activities in relation to training and capacity strengthening. The Review Panel was composed of Elliot Stern (Chair), Lucia de Vaccaro and John Lyna

Systemwide Reviews in the CGIAR: Concepts, Options, and Recommendations

Study commissioned by the Oversight Committee of system-wide reviews in the CGIAR, conducted by a team headed by Martin Piñeiro and including Elliott Stern, and Dana Dalrymple. The study was considered by the Oversight Committee at CGIAR International Centers Week 2000, and circulated to CGIAR members. The Committee said it would implement the 15 recommendations of the study, and invited comments.Originally conceived as a retrospective review of the third system review of the CGIAR, the study was expanded to cover the first two system reviews, and system-level review processes in general. The study found that in contrast to the first two, the third review of the System suffered from the combination of a largely external review panel whose members were unfamiliar with the CGIAR, and the lack of preparatory work to define the issues. It considered various options for future reviews from the point of view of objectives, structure, and procedure, and made recommendations for each.There are two annexes with detailed information on the CGIAR review system, and the third System Review

Discovery of carbon monoxide in the upper atmosphere of Pluto

Pluto's icy surface has changed colour and its atmosphere has swelled since its last closest approach to the Sun in 1989. The thin atmosphere is produced by evaporating ices, and so can also change rapidly, and in particular carbon monoxide should be present as an active thermostat. Here we report the discovery of gaseous CO via the 1.3mm wavelength J=2-1 rotational transition, and find that the line-centre signal is more than twice as bright as a tentative result obtained by Bockelee-Morvan et al. in 2000. Greater surface-ice evaporation over the last decade could explain this, or increased pressure could have caused the atmosphere to expand. The gas must be cold, with a narrow line-width consistent with temperatures around 50 K, as predicted for the very high atmosphere, and the line brightness implies that CO molecules extend up to approximately 3 Pluto radii above the surface. The upper atmosphere must have changed markedly over only a decade since the prior search, and more alterations could occur by the arrival of the New Horizons mission in 2015.Comment: 5 pages; accepted for publication in MNRAS Letter

Runaway Growth During Planet Formation: Explaining the Size Distribution of Large Kuiper Belt Objects

Runway growth is an important stage in planet formation during which large protoplanets form, while most of the initial mass remains in small planetesimals. The amount of mass converted into large protoplanets and their resulting size distribution are not well understood. Here, we use analytic work, that we confirm by coagulation simulations, to describe runaway growth and the corresponding evolution of the velocity dispersion. We find that runaway growth proceeds as follows: Initially all the mass resides in small planetesimals, with mass surface density \sigma, and large protoplanets start to form by accreting small planetesimals. This growth continues until growth by merging large protoplanets becomes comparable to growth by planetesimal accretion. This condition sets in when \Sigma/\sigma ~\alpha^{3/4} ~ 10^{-3}, where \Sigma is the mass surface density in protoplanets in a given logarithmic mass interval and \alpha is the ratio of the size of a body to its Hill radius. From then on, protoplanetary growth and the evolution of the velocity dispersion become self-similar and \Sigma remains roughly constant, since an increase in \Sigma by accretion of small planetesimals is balanced by a decrease due to merging with large protoplanets. We show that this growth leads to a protoplanet size distribution given by N(>R) \propto R^{-3} where N(>R) is the number of objects with radii greater than R (i.e., a differential power-law index of 4). We apply our results to the Kuiper Belt, which is a relic of runaway growth. Our results successfully match the observed Kuiper belt size distribution, they illuminate the physical processes that shaped it and explain the total mass that is present in large Kuiper belt objects (KBOs) today. This work suggests that the current mass in large KBOs is primordial and that it has not been significantly depleted. AbridgedComment: 13 pages, 7 figue

The Edgeworth-Kuiper debris disk

(Abridged) The Edgeworth-Kuiper belt with its presumed dusty debris is a natural reference for extrsolar debris disks. We employ a new algorithm to eliminate the inclination and the distance selection effects in the known TNO populations to derive expected parameters of the "true" EKB. Its estimated mass is M_EKB=0.12 M_earth, which is by a factor of \sim 15 larger than the mass of the EKB objects detected so far. About a half of the total EKB mass is in classical and resonant objects and another half is in scattered ones. Treating the debiased populations of EKB objects as dust parent bodies, we then "generate" their dust disk with our collisional code. Apart from accurate handling of collisions and direct radiation pressure, we include the Poynting-Robertson (P-R) drag, which cannot be ignored for the EKB dust disk. Outside the classical EKB, the radial profile of the optical depth approximately follows tau \sim r^-2 which is roughly intermediate between the slope predicted analytically for collision-dominated (r^-1.5) and transport-dominated (r^-2.5) disks. The cross section-dominating grain size still lies just above the blowout size (\sim 1...2 \microm), as it would without the P-R transport. However, if the EKB were by one order of magnitude less massive, the optical depth profile would fall off as tau \sim r^-3, and the cross section-dominating grain size would shift from \sim 1...2\microm to ~100 \microm. These properties are seen if dust is assumed to be generated only by known TNOs. If the solar system were observed from outside, the thermal emission flux from the EKB dust would be about two orders of magnitude lower than for solar-type stars with the brightest known infrared excesses observed from the same distance. Herschel and other new-generation facilities should reveal extrasolar debris disks nearly as tenuous as the EKB disk. The Herschel/PACS instrument should be able to detect disks at a \sim 1...2M_EKB level.Comment: 18 pages, 14 figures, accepted for publication in A&

THE THEORY AND MEASUREMENT OF ELASTICITY OF SUBSTITUTION IN INTERNATIONAL TRADE 1

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73671/1/j.1467-6435.1962.tb00077.x.pd

A single sub-km Kuiper Belt object from a stellar Occultation in archival data

The Kuiper belt is a remnant of the primordial Solar System. Measurements of its size distribution constrain its accretion and collisional history, and the importance of material strength of Kuiper belt objects (KBOs). Small, sub-km sized, KBOs elude direct detection, but the signature of their occultations of background stars should be detectable. Observations at both optical and X-ray wavelengths claim to have detected such occultations, but their implied KBO abundances are inconsistent with each other and far exceed theoretical expectations. Here, we report an analysis of archival data that reveals an occultation by a body with a 500 m radius at a distance of 45 AU. The probability of this event to occur due to random statistical fluctuations within our data set is about 2%. Our survey yields a surface density of KBOs with radii larger than 250 m of 2.1^{+4.8}_{-1.7} x 10^7 deg^{-2}, ruling out inferred surface densities from previous claimed detections by more than 5 sigma. The fact that we detected only one event, firmly shows a deficit of sub-km sized KBOs compared to a population extrapolated from objects with r>50 km. This implies that sub-km sized KBOs are undergoing collisional erosion, just like debris disks observed around other stars.Comment: To appear in Nature on December 17, 2009. Under press embargo until 1800 hours London time on 16 December. 19 pages; 7 figure

Introduction – Rethinking Impact Evaluation for Development

This IDS Bulletin is the first of two special issues presenting contributions from the event ‘Impact Innovation and Learning: Towards a Research and Practice Agenda for the Future’, organised by IDS in March 2013. The initiative, as well as these two issues, represent a ‘rallying cry’ for impact evaluation to rise to the challenges of a post?MDG/post?2015 development agenda. This introduction articulates first what these challenges are, and then goes on to summarise how the contributors propose to meet these challenges in terms of methodological and institutional innovation. Increasingly ambitious development goals, multiple layers of governance and lines of accountability require adequate causal inference frameworks and less ambitious expectations on the span of direct influence single interventions can achieve, as well as awareness of multiple bias types. Institutions need to be researched and become more impact?oriented and learning?oriented

Across-arc geochemical variations in the Southern Volcanic Zone, Chile (34.5- 38.0°S): Constraints on Mantle Wedge and Input Compositions

Crustal assimilation (e.g. Hildreth and Moorbath, 1988) and/or subduction erosion (e.g. Stern, 1991; Kay et al., 2005) are believed to control the geochemical variations along the northern portion of the Chilean Southern Volcanic Zone. In order to evaluate these hypotheses, we present a comprehensive geochemical data set (major and trace elements and O-Sr-Nd-Hf-Pb isotopes) from Holocene primarily olivine-bearing volcanic rocks across the arc between 34.5-38.0°S, including volcanic front centers from Tinguiririca to Callaqui, the rear arc centers of Infernillo Volcanic Field, Laguna del Maule and Copahue, and extending 300 km into the backarc. We also present an equivalent data set for Chile Trench sediments outboard of this profile. The volcanic arc (including volcanic front and rear arc) samples primarily range from basalt to andesite/trachyandesite, whereas the backarc rocks are low-silica alkali basalts and trachybasalts. All samples show some characteristic subduction zone trace element enrichments and depletions, but the backarc samples show the least. Backarc basalts have higher Ce/Pb, Nb/U, Nb/Zr, and Ta/Hf, and lower Ba/Nb and Ba/La, consistent with less of a slab-derived component in the backarc and, consequently, lower degrees of mantle melting. The mantle-like δ18O in olivine and plagioclase phenocrysts (volcanic arc = 4.9-5.6 and backarc = 5.0-5.4 per mil) and lack of correlation between δ18O and indices of differentiation and other isotope ratios, argue against significant crustal assimilation. Volcanic arc and backarc samples almost completely overlap in Sr and Nd isotopic composition. High precision (double-spike) Pb isotope ratios are tightly correlated, precluding significant assimilation of older sialic crust but indicating mixing between a South Atlantic Mid Ocean-Ridge Basalt (MORB) source and a slab component derived from subducted sediments and altered oceanic crust. Hf-Nd isotope ratios define separate linear arrays for the volcanic arc and backarc, neither of which trend toward subducting sediment, possibly reflecting a primarily asthenospheric mantle array for the volcanic arc and involvement of enriched Proterozoic lithospheric mantle in the backarc. We propose a quantitative mixing model between a mixed-source, slab-derived melt and a heterogeneous mantle beneath the volcanic arc. The model is consistent with local geodynamic parameters, assuming water-saturated conditions within the slab