1,966 research outputs found
Windfall management for poverty reduction : improving public finance Management-the case of Chad
No full textThis paper aims at providing a guide to ensure efficiency in the management of Chad's windfall to support the development process and poverty reduction. The analysis is based on the lessons and experience of countries that have successfully used natural-resource-generated windfalls to launch their development process while avoiding the natural resource curse. The paper also discusses the petroleum management arrangements in place in Chad for poverty reduction. The author argues that the successful management of Chad's windfall for poverty reduction will depend on the effectiveness of oil revenue management arrangements in place in Chad and the government's willingness to improve public finance management (PFM).Public Sector Expenditure Analysis&Management,Debt Markets,,Public Sector Economics&Finance,Banks&Banking Reform
Spor, Chad and Ray
No full textChad and Ray Spor, sons of George Spor. Fluorspar of the Topaz Mountain district was developed by George A. Spor 1941. They shipped the ore to Geneva Steel near Provo, Utah. The steel industry is the primary user of fluorspar. Others are the ceramic and acid industrie
Data for "Deep Learning Cosmic Ray Transport from Density Maps of Simulated, Turbulent Gas"
No full textSeparated training, validation, and test data from a set of magnetohydrodynamic turbulent box simulations, including a relativistic cosmic ray fluid spanning a range of cosmic ray transport modes: no cosmic rays (MHD), cosmic ray advection (CR_Advect), fiducial cosmic ray diffusion (CR_Diff_Fiducial), fiducial diffusion x 100 (CR_Diff100), and diffusion plus streaming (CR_withStreaming).
Note this dataset comprises the "Full Power" images from Bustard and Wu 2024, submitted to Machine Learning Science and Technology. Scripts to analyze this data are available at https://github.com/bustardchad/ML_Turb.
Paper abstract: "The coarse-grained propagation of Galactic cosmic rays (CRs) is traditionally constrained by phenomenological models of Milky Way CR propagation fit to a variety of direct and indirect observables; however, constraining the fine-grained transport of CRs along individual magnetic field lines -- for instance, diffusive vs streaming transport models -- is an unsolved challenge. Leveraging a recent training set of magnetohydrodynamic turbulent box simulations, with CRs spanning a range of transport parameters, we use convolutional neural networks (CNNs) trained solely on gas density maps to classify CR transport regimes. We find that even relatively simple CNNs can quite effectively classify density slices to corresponding CR transport parameters, distinguishing between streaming and diffusive transport, as well as magnitude of diffusivity, with class accuracies between 92% and 99%. As we show, the transport-dependent imprints that CRs leave on the gas are not all tied to the resulting density power spectra: classification accuracies are still high even when image spectra are flattened (85% to 98% accuracy), highlighting CR transport-dependent changes to turbulent phase information. We interpret our results with saliency maps and image modifications, and we discuss physical insights and future applications.
Solid-phase phosphorus speciation in Saharan Bodélé depression dusts and source sediments
No full textPhosphorus (P) is one of the most important limiting nutrients for the growth of oceanic phytoplankton and terrestrial ecosystems, which in turn contributes to CO2 sequestration. The solid-phase speciation of P will influence its solubility and hence its availability to such ecosystems. This study reports on the results of X-ray diffraction, electron microprobe chemical analysis and X-ray mapping, chemical extractions and X-ray absorption near-edge spectroscopy analysis carried out to determine the solid-phase speciation of P in dusts and their source sediments from the Saharan Bodélé Depression, the world’s largest single source of dust. Chemical extraction data suggest that the Bodélé dusts contain 28 to 60% (mean 49%) P sorbed to, or co-precipitated with Fe (hydr)oxides, < 10% organic P, 21-50% (mean 32%) detrital apatite P, and 10-22% (mean 15%) authigenic-biogenic apatite P. This is confirmed by the other analyses, which also suggest that the authigenic-biogenic apatite P is likely fish bone and scale, and that this might form a larger proportion of the apatite pool (33 +/− 22%) than given by the extraction data. This is the first-ever report of fish material in aeolian dust, and it is significant because P derived from fish bone and scale is relatively soluble and is often used as a soil fertilizer. Therefore, the fish-P will likely be the most readily form of Bodélé P consumed during soil weathering and atmospheric processing, but given time and acid dissolution, the detrital apatite, Fe-P and organic-P will also be made available. The Bodélé dust input of P to global ecosystems will only have a limited life, however, because its major source materials, diatomite in the Bodélé Depression, undergo persistent deflation and have a finite thickness
Chad Genetic Diversity Reveals an African History Marked by Multiple Holocene Eurasian Migrations
No full textUnderstanding human genetic diversity in Africa is important for interpreting the evolution of all humans, yet vast regions in Africa, such as Chad, remain genetically poorly investigated. Here, we use genotype data from 480 samples from Chad, the Near East, and southern Europe, as well as whole-genome sequencing from 19 of them, to show that many populations today derive their genomes from ancient African-Eurasian admixtures. We found evidence of early Eurasian backflow to Africa in people speaking the unclassified isolate Laal language in southern Chad and estimate from linkage-disequilibrium decay that this occurred 4,750–7,200 years ago. It brought to Africa a Y chromosome lineage (R1b-V88) whose closest relatives are widespread in present-day Eurasia; we estimate from sequence data that the Chad R1b-V88 Y chromosomes coalesced 5,700–7,300 years ago. This migration could thus have originated among Near Eastern farmers during the African Humid Period. We also found that the previously documented Eurasian backflow into Africa, which occurred ∼3,000 years ago and was thought to be mostly limited to East Africa, had a more westward impact affecting populations in northern Chad, such as the Toubou, who have 20%–30% Eurasian ancestry today. We observed a decline in heterozygosity in admixed Africans and found that the Eurasian admixture can bias inferences on their coalescent history and confound genetic signals from adaptation and archaic introgression
Editorial Comment
No full textByline: Chad R. Ritch Author Affiliation: Vanderbilt University Medical Center, Nashville, TennesseeAcademi
Covid-19 Data from Senegal and Chad
No full textDescription of the files containing the data on covid-19 in Senegal and Chad. They are collected and calculated by the author and are freely available under creative comon open licens
Post-UN Withdrawal: An Assessment of Peacekeeping in Chad
No full textThe primary task of the parallel UN and European Union peace operations to Chad and the Central African Republic s (CAR) borders with Sudan in 2008 was protection of civilians and humanitarian workers. Delays in deployment by both EUFOR and MINURCAT undermined the operational effectiveness of the overall mission. Resistance by the government of Chad to the presence of an international UN force became problematic during 2010. Neither operation is reported to have succeeded in improving the overall security situation in both countries. A weakness of both operations was that each dealt with the consequences but not the root causes of the conflict. Despite continued insecurity, the UN peacekeeping mission, MINURCAT, withdrew late in 2010. Despite the provisions in Chapter VII of the UN Charter authorising intervention in the domestic affairs of a state, the political realities meant that MINURCAT could not function with the consent of the host state. This demonstrated the weakness in the legal regime governing the maintenance of international peace and security. Did the mission succeed in providing and creating a safe environment for vulnerable groups? What are the lessons to be learned and who will protect those groups in the absence of an international military force
Changing alignments: meanders of the political elite in Chad
No full textAt the outset the author shows the geographical and cultural background the country. Then he describes its creation and the most significant events of the independent state. In the presentation the author emphasizes that there are many opposing views on causes and the course of the civil strife in Chad from the first years of its independence. He summarises the most common explanations and points out that they are often based on stereotypes and subjective selected facts from the History of the country. He states that in these explanations there is much truth but they have to be taken into account in their totality and not on a selective basis. The author emphasizes the role played by France in creating colonial and independent Chad and continues to be involved by many armed interventions. He points to the changeable politics of Sudan and Libya towards the republic of Chad and also to the financial and other involvement of the USA and even Israel. He also discusses the role of „social class" and „professional classes" in the conflict, the role of Marxist ideology, cultural role of traditional communities and their segmentation. He underlines that these last ones from their nature have a limited role in the creation of state structures in the European sense. He explains many complicated interpersonal relations in the internal politics of Chad. Finally he puts the question as to whether this state is capable of existing and shows admiration for the many small local structures which allows the local people to survive
progress report FY 2004-2005
No full textPI: Michael Qian, Oregon State University ; collaborators: Chad Finn, USDA-ARS HCRL, Jan-Marie Schroeder, Oregon Raspberry & Blackberry Commission.This archived document is maintained by the State Library of Oregon as part of the Oregon Documents Depository Program. It is for informational purposes and may not be suitable for legal purposes.Mode of access: Internet from the Oregon Government Publications Collection.Text in English
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