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Data, Metrics and Monitoring in CGIAR - a strategic study
This document contains the final report of the Panel together with the ISPC commentary. The Panel Report presents an analysis of the current activities within CGIAR concerning data, metrics and indicators, and offers a series of recommendations to address the key issues and challenges identified
Frontal plane roll-over analysis of prosthetic feet
In prosthetic walking mediolateral balance is compromised due to the lack of active ankle control, by moments of force, in the prosthetic limb. Active control is reduced to the hip strategy, and passive mechanical stability depends on the curvature of the prosthetic foot under load. Mediolateral roll-over curvatures of prosthetic feet are largely unknown. In this study we determined the mediolateral roll-over characteristics of various prosthetic feet and foot-shoe combinations. Characteristics were determined by means of an inverted pendulum-like apparatus. The relationship between the centre of pressure (CoP) and the shank angle was measured and converted to roll-over shape and effective radius of curvature. Further, hysteresis (i.e., lagging in CoP displacement due to material compliance or slip) at vertical shank angle was determined from the hysteresis curve. Passive mechanical stability varied widely, though all measured foot-shoe combinations were relatively compliant. Mediolateral motion of the CoP ranged between 4 mm and 40 mm, thereby remaining well within each foot's physical width. Derived roll-over radii of curvature are also small, with an average of 102 mm. Hysteresis ranges between 20% and 115% of total CoP displacement and becomes more pronounced when adding a shoe. This may be due to slipping of the foot core in its cosmetic cover, or the foot in the shoe. Slip may be disadvantageous for balance control by limiting mediolateral travel of the CoP. It may therefore be clinically relevant to eliminate mediolateral slip in prosthetic foot design
Soil quality and constraints in global rice production
We assessed soil quality in global rice production areas with the Fertility Capability Soil Classification (FCC) system adjusted to match the harmonized world soil database, established by the Food and Agriculture Organization and the International Institute for Applied Systems Analysis. We computed the distribution of 20 soil constraints, and used these to categorize soils as 'good', 'poor', 'very poor', or 'problem soil' for rice production. These data were then combined with data of global rice distribution to determine soil quality in the main rice production systems around the world. Most rice is grown in Asia (143.4. million. ha), followed by Africa (10.5. million. ha) and the Americas (7.2. million. ha). Globally, one-third of the total rice area is grown on very poor soils, which includes 25.6. million. ha of irrigated rice land, 18.5. million. ha in rainfed lowlands, and 7.5. million. ha of upland rice. At least 8.3. million. ha of rice is grown on problem soils, including saline, alkaline/sodic, acid-sulfate, and organic soils. Asia has the largest percentage of rice on good soils (47%) whereas rice production on good soils is much less common in the Americas (28%) and accounts for only 18% in Africa. The most common soil chemical problems in rice fields are very low inherent nutrient status (35.8. million. ha), very low pH (27.1. million. ha), and high P fixation (8.1. million. ha); widespread soil physical problems especially severe in rainfed environments are very shallow soils and low water-holding capacity. The results of the analysis can be used to better target crop improvement research, plant breeding, and the dissemination of stress-specific tolerant varieties and soil management technologies. © 2014 Elsevier B.V.S.M. Haefele, A. Nelson, R.J. Hijman
Trophic interactions will expand geographically but be less intense as oceans warm
Interactions among species are likely to change geographically due to climate-driven
species range shifts and in intensity due to physiological responses to increasing temperatures.
Marine ectotherms experience temperatures closer to their upper thermal
limits due to the paucity of temporary thermal refugia compared to those available to
terrestrial organisms. Thermal limits of marine ectotherms also vary among species
and trophic levels, making their trophic interactions more prone to changes as oceans
warm. We assessed how temperature affects reef fish trophic interactions in the
Western Atlantic and modeled projections of changes in fish occurrence, biomass,
and feeding intensity across latitudes due to climate change. Under ocean warming,
tropical reefs will experience diminished trophic interactions, particularly herbivory
and invertivory, potentially reinforcing algal dominance in this region. Tropicalization
events are more likely to occur in the northern hemisphere, where feeding by tropical
herbivores is predicted to expand from the northern Caribbean to extratropical reefs.
Conversely, feeding by omnivores is predicted to decrease in this area with minor increases
in the Caribbean and southern Brazil. Feeding by invertivores declines across
all latitudes in future predictions, jeopardizing a critical trophic link. Most changes
are predicted to occur by 2050 and can significantly affect ecosystem functioning,
causing dominance shifts and the rise of novel ecosystems.Postprint6,86
Application of the Coupling Angle to Investigate Upper Limb Interjoint Coordination After Stroke
Objective: Interjoint coordination after stroke is affected, which limits the use of the upper limb. Current methods to determine interjoint coordination lack the ability to visualize and quantify the movement. Therefore we investigated if the coupling angle can be used to visualize and interpret upper limb interjoint coordination following a stroke. Methods: Seven chronic stroke patients trained six weeks with an assistive home-training system (MERLIN). Kinematic outcomes, i.e. elbow and shoulder range of motion, movement duration, and angle-angle plots were determined in a retrieving task. Interjoint coordination between elbow flexion and shoulder abduction angles was expressed as the coupling angle phases and the number of phase transitions: proximal/distal joint leading phase, in-phase and anti-phase. Comparisons were made within sides: pre-test versus post-test, and between sides: most-affected (MA) versus least-affected (LA). Results: Smaller elbow flexion angles were found PreMA versus PreLA, and smaller shoulder abduction angles in PostMA versus PostLA. A general coordination pattern was revealed on the LA side, but not on the MA side. A trend showed less phase transitions at the MA side after training, suggesting a smoother movement. Quantification of the movement phases indicated more involvement of the shoulder joint involvement in the MA side during pre-test. After training, these differences were not apparent, which might reveal an increased independent control of the elbow joint. Conclusions: The coupling angle and the movement phases provide a promising tool to investigate post-stroke interjoint coordination patterns. Significance: A new visualisation of the interjoint coordination may benefit rehabilitation of stroke survivors. Registration: This trial was registered at the Netherlands Trial Register (NL7535) https://www.trialregister.nl/trial/7535.</p
Adiabatically changing the phase-space density of a trapped Bose gas
We show that the degeneracy parameter of a trapped Bose gas can be changed
adiabatically in a reversible way, both in the Boltzmann regime and in the
degenerate Bose regime. We have performed measurements on spin-polarized atomic
hydrogen in the Boltzmann regime demonstrating reversible changes of the
degeneracy parameter (phase-space density) by more than a factor of two. This
result is in perfect agreement with theory. By extending our theoretical
analysis to the quantum degenerate regime we predict that, starting close
enough to the Bose-Einstein phase transition, one can cross the transition by
an adiabatic change of the trap shape.Comment: 4 pages, 3 figures, Latex, submitted to PR
NMR imaging of the soliton lattice profile in the spin-Peierls compound CuGeO_3
In the spin-Peierls compound CuGeO, the commensurate-incommensurate
transition concerning the modulation of atomic position and the local
spin-polarization is fully monitored at T=0 by the application of an external
magnetic field () above a threshold value 13 Tesla. The
solitonic profile of the spin-polarization, as well as its absolute magnitude,
has been precisely imaged from NMR lineshapes obtained for
varying from 0.0015 to 2. This offers a unique possibility
to test quantitatively the various numerical and analytical methods developed
to solve a generic Hamiltonian in 1-D physics, namely strongly interacting
fermions in presence of electron-phonon coupling at arbitrary band filling.Comment: 3 pages, 4 eps figures, RevTeX, submitted to Physical Review Lette
Damagnetization cooling of a gas
We demonstrate demagnetization cooling of a gas of ultracold Cr atoms.
Demagnetization is driven by inelastic dipolar collisions which couple the
motional degrees of freedom to the spin degree. By that kinetic energy is
converted into magnetic work with a consequent temperature reduction of the
gas. Optical pumping is used to magnetize the system and drive continuous
demagnetization cooling. Applying this technique, we can increase the phase
space density of our sample by one order of magnitude, with nearly no atom
loss. This method can be in principle extended to every dipolar system and
could be used to achieve quantum degeneracy via optical means.Comment: 10 pages, 5 figure
Competition and coexistence of bond and charge orders in (TMTTF)2AsF6
(TMTTF)2AsF6 undergoes two phase transitions upon cooling from 300 K. At
Tco=103 K a charge-ordering (CO) occurs, and at Tsp(B=9 T)=11 K the material
undergoes a spin-Peierls (SP) transition. Within the intermediate, CO phase,
the charge disproportionation ratio is found to be at least 3:1 from carbon-13
NMR 1/T1 measurements on spin-labeled samples. Above Tsp, up to about 3Tsp,
1/T1 is independent of temperature, indicative of low-dimensional magnetic
correlations. With the application of about 0.15 GPa pressure, Tsp increases
substantially, while Tco is rapidly suppressed, demonstrating that the two
orders are competing. The experiments are compared to results obtained from
calculations on the 1D extended Peierls-Hubbard model.Comment: 4 pages, 5 figure
Modulated Phases in Spin-Peierls Systems
Lattice modulations in the high magnetic field phase and close to impurities
in spin-Peierls systems are considered and compared to experiment. Necessary
extensions of existing theories are proposed. The influence of zero-point
fluctuations on magnetic amplitudes is shown.Comment: 10 pages, 4 figures included, to appear in Advances in Solid State
Physics/Festkoerperprobleme Spring Conference 1999 of the DP
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