574 research outputs found
Ethnicity and Local Identity in de Folklore of the South-western Oromo of Ethiopia: a Comparative Study
Abbink, G.J. [Promotor
Estimation du stock de carbone dans les faciès arborés et arbustifs des savanes soudano-guinéennes de Ngaoundéré, Cameroun.
Une des conséquences environnementales de la dégradation forestière est la perte de carbone, qui à son tour contribue indirectement au changement climatique. Dans la perspective d\'évaluer la contribution des savanes de l\'Adamaoua dans le changement climatique, une étude portant sur l\'estimation de stock du carbone a été menée dans les faciès arbustifs et arborés. La quantité de carbone a été estimée dans des parcelles carrées de 100 m2 pour les arbres et les arbustes, de 1 m2 pour le sous-bois et de 0,0625 m2 pour les racines et le sol. Le dispositif expérimental est un bloc complètement randomisé à trois répétitions. Les types de savanes sont des traitements principaux et les parcelles les répétitions. Les résultats montrent que la quantité totale de carbone est de l\'ordre de 81,48 et 118,36 tC/ha respectivement pour la savane arbustive et arborée. Dans la savane arborée, l\'essentiel de carbone est stocké dans la phytomasse des arbres (65,30 tC/ha) et dans le sol (48,37 tC/ha); la contribution des arbustes (3,83t/ha) des herbacées (0,30t/ha), des racines (1,96 tC/ha) et des litières (1,88 tC/ha) est faible, moins de 5% de carbone totale. Par contre, dans la savane arbustive, le sol constitue le principal réservoir de carbone (74,35 tC/ha). Les autres composantes à savoir les arbustes (0,66 tC/ha), les herbacées (3,15 tCha), les racines (1,98 tC/ha) et les litières (1,34 tC/ha) ont une contribution très faible, moins de 9% de la quantité totale de carbone. Les différences observées entre la savane arborée et arbustive sont dues en grande partie à la différence de leur structure et de leur composition floristique. Ces résultats préliminaires contribuent à la compréhension de l\'impact des conversions des savanes sur le changement climatique. Ceci permettra une prise de décision dans la gestion durable des savanes et la protection de l\'environnement.One of the environmental consequences of the modification of savannas is a carbon loss which in turn contributes indirectly to global climate change. In order to evaluate contribution of Adamawa savannas in global climate change, a study on the sequestration of carbon was conducted both in a shrubby and woody savannas of Ngaoundere. The quantity of carbon was estimated in a square plot of 100 m2 for the trees and shrubs, of 1m2 for grass and 0.0625 m2 for the roots and the soils. The experimental design is a randomized complete block with three replicates. The type of savannas are main treatment whereas the plots are replicates. The results show that the total average of carbon is about 81.48 tC/ha in shrubby savannas and 118.36 tC/ha in woody savannas. In the woody savannas, the essential of carbon was stored in the trees (65.30 tC/ha) and in the soil (48.37 tC/ha). Whereas in the shrubby savannas, it is based on in the soil. The contribution of shrubs and grass (0.78 tC/ha), roots (1.96 tC/ha) and litters (1.88 tC/ha) is less than 5% of the global quantity of carbon. Shrubby savannas soil appears to be the main carbon tank (74.35 tC/ha). The other components of shrubby savannas as shrubs, grass, litters and roots contributed for less than 9% in the total amount of carbon. The differences noticed between the type of savannas are due to their floristic structure et composition. These preliminary results contribute to the understanding impacts of savannas conversion to global climate change. This would allow to make decision in sustainable management of savannas and environment protection. Keywords: Phytomass, Carbon storage, soudano-guinea savannas, Ngaoundere, CameroonCameroon Journal of Experimental Biology Vol. 4 (1) 2008: pp. 1-1
Effect of curing conditions and harvesting stage of maturity on Ethiopian onion bulb drying properties
The study was conducted to investigate the impact of curing conditions and harvesting stageson the drying quality of onion bulbs. The onion bulbs (Bombay Red cultivar) were harvested at three harvesting stages (early, optimum, and late maturity) and cured at three different temperatures (30, 40 and 50 oC) and relative humidity (30, 50 and 70%). The results revealed that curing temperature, RH, and maturity stage had significant effects on all measuredattributesexcept total soluble solids
Book review
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43866/1/11256_2005_Article_BF01958807.pd
“As Tough As It Gets”: Women in Boston Politics, 1921-2004
This study seeks to answer the question: Given the wealth of talent and resources women possess—and the state offers—why is it so tough for women to gain representation in Boston City Hall? To answer this question, and to document the efforts women have made over almost 100 years, we examine the history of women who have run for and won—or lost—election to the Boston City Council in the 20th century. How does the structure and culture of a given urban political arena (i.e., “Boston politics”) affect women’s opportunities as elected officials? What is women’s political culture and how has it differed from patriarchal models of urban political culture? What constitutes political ambition and participation for women? How do women fare in Boston compared to other capital cities in the United States?
This history of women and the Boston City Council uses public records, media reports, and oral histories with candidates and elected officials to tell a story that fills a gap in scholarship regarding the roles of women in Boston city politics. First, we will provide a brief description of the historical context—how “Boston politics” has shaped, hindered, or, in some cases, promoted women’s election to the City Council. Second, using data gathered from historical records, oral histories, interviews, and other sources, we will provide a chronological history of women who ran, won, and lost their bids for election. Finally, the paper concludes with an analysis of the reasons it has been so difficult for women to gain anything approaching equal representation on the Boston City Council. This analysis includes systemic constraints such as bias in gender roles and expectations; traditional notions about women’s capabilities and responsibility; familiarity with the political process; the role of gatekeepers; and fundraising and other forms of support
Detection rate of actionable mutations in diverse cancers using a biopsy-free (blood) circulating tumor cell DNA assay.
Analysis of cell-free DNA using next-generation sequencing (NGS) is a powerful tool for the detection/monitoring of alterations present in circulating tumor DNA (ctDNA). Plasma extracted from 171 patients with a variety of cancers was analyzed for ctDNA (54 genes and copy number variants (CNVs) in three genes (EGFR, ERBB2 and MET)). The most represented cancers were lung (23%), breast (23%), and glioblastoma (19%). Ninety-nine patients (58%) had at least one detectable alteration. The most frequent alterations were TP53 (29.8%), followed by EGFR (17.5%), MET (10.5%), PIK3CA (7%), and NOTCH1 (5.8%). In contrast, of 222 healthy volunteers, only one had an aberration (TP53). Ninety patients with non-brain tumors had a discernible aberration (65% of 138 patients; in 70% of non-brain tumor patients with an alteration, the anomaly was potentially actionable). Interestingly, nine of 33 patients (27%) with glioblastoma had an alteration (6/33 (18%) potentially actionable). Overall, sixty-nine patients had potentially actionable alterations (40% of total; 69.7% of patients (69/99) with alterations); 68 patients (40% of total; 69% of patients with alterations), by a Food and Drug Administration (FDA) approved drug. In summary, 65% of diverse cancers (as well as 27% of glioblastomas) had detectable ctDNA aberration(s), with the majority theoretically actionable by an approved agent
Texture and microstructure evolution in nickel electrodeposited from an additive-free Watts electrolyte
Impact of Trivalent Arsenicals on Selenoprotein Synthesis
BACKGROUND: Exposure to arsenic has been associated with development of skin, lung, bladder, liver, and kidney cancer. Recent evidence suggests that an increase in oxidative stress in cells treated with arsenicals represents the molecular mechanism behind arsenic-induced carcinogenesis. Selenium, in the form of selenocysteine, is necessary for the activity of several enzymes with a role in defense against reactive oxygen species. A mutual sparing effect between arsenic and selenium has been shown in animal studies when both metalloids are present in high concentrations. OBJECTIVES: To determine whether changes in selenoprotein synthesis may be an underlying mechanism behind arsenic-induced carcinogenesis, we analyzed the new synthesis of selenoproteins within cells after exposure to inorganic or methylated arsenicals using a human keratinocyte cell model. RESULTS: Addition of arsenite to culture medium blocked new synthesis of selenoproteins when selenium was present in the form of selenite, and appeared to stimulate the use of serum-derived selenium. Monomethylarsonous acid (MMA(III)) treatment of cells, in contrast, did not block all new synthesis of selenoproteins but did result in an increase in cytosolic thioredoxin reductase (TrxR1) at both the mRNA and protein levels. MMA(III) also reduced the new synthesis of cellular glutatione peroxidase (cGpx) and other smaller selenoproteins. Dimethylarsinous acid (DMA(III)) stimulated selenoprotein synthesis by an as yet unknown mechanism. CONCLUSIONS: These results suggest that arsenite and MMA(III) are key metabolites that trigger higher levels of TrxR1, and both lead to a reduction in the expression of cGpx. Together these effects certainly could lead to carcinogenesis given the knowledge that many cancers have higher levels of TrxR, and reduced Gpx levels will reduce the cell’s ability to defend against reactive oxygen species. Based on these results, the impact of the trivalent arsenicals arsenite and MMA(III) on selenoprotein synthesis may indeed represent a potential molecular mechanism for the higher rates of cancer observed in populations exposed to high levels of arsenic
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