1,152 research outputs found
Marine Geology of Baie des Chaleurs
Baie des Chaleurs is the fourth largest estuary in eastern Canada. The bay is a broad and shallow basin, filled with up to 50 m of unconsolidated Quaternary sediment. The distribution of this sedimentary mass is in part controlled by a Cenozoic (Tertiary or Quaternary) drainage system that follows the main structural elements of the underlying Paleozoic sedimentary bedrock. Ice-contact Pleistocene sediment, including till, is generally thin or absent. However, in the central and outer bay the Cenozoic channels contain linear morainal accumulations up to 30 m thick. These deposits may indicate the terminal position of the Gaspé ice dome. Six large but separate glacimarine fans mark the position of major discharge outlets that operated during the retreat phase of the regional ice sheets. These Pleistocene deposits were partly eroded by glacifluvial drainage channels during a low sea level stand (-90 m) circa 9000 years BP. Subsequently, during the early to middle Holocene marine transgression, the glacigenic sediments were subjected to wave erosion. These deposits thus thin towards shallower water and are marked by shore-parallel terraces and surface lags along the margins of the bay. By 7000 years BP, a sandur complex located in the shallower inner bay was also transgressed by the rising sea. Early Holocene sedimentation occurred initially in the deeper waters of the central and outer bay, and subsequently formed an extensive veneer across the inner bay sandur with rising sea levels. These paraglacial sediments show a progression in bedding styles and particle size related to sea level position and sediment source. Modern océanographie conditions became established circa 5000 years ago, and include increased tidal and wave activity, and decreased sediment discharge. Modern sediments are deposited principally beneath a mid-bay gyre set up by the influx of the Gaspé current along the north shore and the efflux of fresher water along the New Brunswick shore.La baie des Chaleurs, quatrième estuaire en importance de l’est du Canada, est un large bassin peu profond rempli de sédiments non consolidés d'une épaisseur allant jusqu'à 50 m. La répartition de cette masse sédimentaire est en partie imposée par le réseau de drainage datant du Cénozoïque (Tertiaire ou Quaternaire), qui suit les principaux éléments structuraux du socle sédimentaire sous-jacent. Les dépôts de contact glaciaire pleistocenes, y compris le till, sont généralement minces ou absents. Toutefois, au centre et vers l’extérieur de la baie, les chenaux cénozoïques renferment les accumulations morainiques linéaires, jusqu'à 30 m d'épaisseur, qui pourraient signaler l'emplacement final du dôme de la Gaspésie. Six grands cônes glaciomarins identifient les exutoires en fonction pendant la phase de retrait des calottes régionales. Ces dépôts pléistocènes ont en partie été érodes par des chenaux de drainage fluvioglaciaires pendant une phase de bas niveau marin (-90 m), vers 9000 BP. Par la suite, au cours de la transgression marine de l'Holocène inférieur à moyen, les sédiments glaciaires ont été soumis à l’érosion par les vagues. Les dépôts s'amincissent donc en eaux peu profondes et sont caractérisés par la présence de terrasses parallèles à la rive et des surfaces de sédiments grossiers le long des marges de la baie. À 7000 BP, le complexe de sandur qui occupait le fond peu profond de la baie a aussi été atteint par la transgression marine. La surface du delta était protégée par une barrière morainique. Les sédiments de l'Holocène inférieur ont d'abord été déposés dans les eaux plus profondes du centre et de l'entrée de la baie et ont subséquemment formé une pellicule sur le sandur du fond de la baie à mesure que le niveau marin montait. Ces sédiments montrent une progression dans la stratification et la granulométrie en relation avec les fluctuations du niveau marin et des sources sédimentaires. Les conditions océanographiques modernes se sont établies il y a environ 5000 ans.Die Baie des Chaleurs ist das viertgrôBte Mùndungsbecken in Ostkanada. Die Bucht ist ein breites und fla-ches Becken, das mit bis zu 50 m dicken, nicht konsolidierten Quaternâr-Ablagerungen angefullt ist. Die Verteilung dieser Sediment-Masse wird zum Teil durch ein AbfluBsystem aus dem Cenozoikum (Tertiar oder Quaternàr) kontrolliert, das den hauptsàchlichen Strukturelementen der darunterliegenden Ablagerung anstehenden Ges-teins aus dem Palàozoikum folgt. Eis-Kontakt-Sediment aus dem Pleistozàn einschlieBlich Till ist im allgemeinen dùnn oder nicht vorhanden. Indessen enthalten die Cenozoikum-Kanàle im Zentrum und in deràuBeren Bucht bis zu 30 m dicke, lineare Morànen-Akkumulationen. Dièse Ablagerun-gen kônnten die Endposition des Gaspé-Eisdoms anzeigen. Sechs breite aber getrennte glaziomarine Fâcher zeigen die Position der wichtigsten Wasserabflùsse an, die wàhrend der Rùckzugsphase der regionalen Eisdecke aktiv waren. Dièse Pleistozàn-Ablagerungen wurden zum Teil durch glazifluviale AbfluBkanàle wàhrend eines niedrigen Meeresniveaus (-90 m) um etwa 9000 Jahre v.u.Z. abgetragen. Danach, wàhrend der marinen Transgression im frùhen bis mittleren Holozàn, unterlagen die glazigenen Ablagerungen einer Abtragung durch Wellen. Dièse Ablagerungen verdùnnen sich auf dièse Weise zum seichteren Wasser hin, und zeichnen sich durch parallel zur Kùste liegende Terrassen und Flàchen groben Sediments entlang den Rândern der Bucht aus. Um 7 000 Jahre v.u.Z. erreichte die Transgression des ansteigenden Meeres einen Sandur-Komplex, der sich in der seichteren inneren Bucht befand. Anfangs kam es zu frùher Holozàn-Sedimentierung in den tieferen Wassern des Zentrums und Eingangs der Bucht, und dièse bildete anschlieBend einen extensiven Schleier durch die Sandur der inneren Bucht, wàhrend der Meeres-spiegel anstieg. Dièse paraglazialen Sedimente weisen eine Progression in der Stratifizierung und der KorngrôBe auf, abhàngig von der Position des Meeresniveaus und der Sedimentquelle
Training of population specialists for Africa’s needs: Past, current and future
Africa has been training population specialists since the early 1960s, following some countries’ acquiring political independence. The training has consisted of undergraduate degrees, post-graduate diplomas, masters, doctorates and postdoctorates at regional and national institutions as well as centres found outside the continent. Achievements of the training programme over several decades have included many population specialists trained and helping in implementing the population related projects in the region and building the capacity of several African population training centres. Challenges have consisted of inadequate financial support from development partners and regional and national governments, lack of scholarships for students, scarce research grants for staff and students, development partners’ related issues, problems related to national and regional governments, lack of interest in supporting training of technical demographers, limitation of infrastructure for training, shortage of qualified trainers and unemployment of graduates in population studies. It is recommended that national governments and regional agencies provide core financing of African population training centres and only mobilize donor funding as supplementary. More focus should be directed to advanced research training to ensure that qualified population specialists lost to the brain drain and other factors are continuously replaced. African training institutions need to be more innovative and create new opportunities of sustainability when the support being received is stopped
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The Lagrangian structure of ozone mini-holes and potential vorticity anomalies in the Northern Hemisphere
An ozone mini-hole is a synoptic-scale area of strongly reduced column total ozone, which undergoes a growth-decay cycle in association with baroclinic weather systems. The tracks of mini-hole events recorded during the TOMS observation period over the Northern Hemisphere provide a database for building anomaly fields of various meteorological parameters, following each mini-hole center in a Lagrangian sense. The resulting fields provide, for the first time, a complete mean Lagrangian picture of the three-dimensional structure of typical ozone mini-holes in the Northern Hemisphere. Mini-holes are shown to be associated with anomalous warm anticyclonic flow in the upper troposphere and cold cyclonic anomalies in the middle stratosphere. Ascending air columns occur upstream and descent downstream of the mini-hole centers. Band-pass filtering is used to reveal the transient synoptic nature of mini-holes embedded within larger scale circulation anomalies. Significant correlations between ozone and Ertel's potential vorticity on isentropes (IPV) both near the tropopause and in the middle stratosphere are shown and then utilized by reconstructing the Lagrangian analysis to follow local IPV anomalies instead of ozone minima. By using IPV as a proxy for ozone, the geopotential anomaly dipolar structure in the vertical characteristics of mini-holes is shown to result from a superposition of two largely independent dynamical components, stratospheric and tropospheric, typically operating on different time scales. Hence, ozone mini-holes may be viewed primarily as phenomena of coincidence
MARRIAGE PATTERNS IN ANKOLE, SOUTH - WESTERN UGANDA
This paper studies marriage patterns and systems in Ankole. Discussed in the study are age at marriage, proportion married, marriage dissolution, remarriages, types of marriage and bridewealth. The paper finds that most of the marriage patterns are among the major causes of high fertility in the area
Geology, Geography, and Humans Battle for Dominance over the Delivery of Fluvial Sediment to the Coastal Ocean
Sediment flux to the coastal zone is conditioned by geomorphic and tectonic influences (basin area and relief), geography (temperature, runoff), geology (lithology, ice cover), and human activities (reservoir trapping, soil erosion). A new model, termed “BQART” in recognition of those factors, accounts for these varied influences. When applied to a database of 488 rivers, the BQART model showed no ensemble over‐ or underprediction, had a bias of just 3% across six orders of magnitude in observational values, and accounted for 96% of the between‐river variation in the long‐term (±30 years) sediment load or yield of these rivers. The geographical range of the 488 rivers covers 63% of the global land surface and is highly representative of global geology, climate, and socioeconomic conditions. Based strictly on geological parameters (basin area, relief, lithology, ice erosion), 65% of the between‐river sediment load is explained. Climatic factors (precipitation and temperature) account for an additional 14% of the variability in global patterns in load. Anthropogenic factors account for an additional 16% of the between‐river loads, although with ever more dams being constructed or decommissioned and socioeconomic conditions and infrastructure in flux, this contribution is temporally variable. The glacial factor currently contributes only 1% of the signal represented by our globally distributed database, but it would be much more important during and just after major glaciations. The BQART model makes possible the quantification of the influencing factors (e.g., climate, basin area, ice cover) within individual basins, to better interpret the terrestrial signal in marine sedimentary records. The BQART model predicts the long‐term flux of sediment delivered by rivers; it does not predict the episodicity (e.g., typhoons, earthquakes) of this delivery
Examination of specimens for mycobacteria in clinical laboratories in 21 countries: a 10-year review of the UK National Quality Assessment Scheme for Mycobacteria Culture
ABSTRACTResults from clinical diagnostic microbiology laboratories taking part in the UK National Quality Assessment Service (UK NEQAS) scheme for Mycobacteria Culture between 1993 and 2003 were evaluated and assessed to determine whether the perceived increase in the use of rapid methods is improving time-to-positive reporting of results. Four simulated sputum specimens containing mycobacteria in mixed cultures with normal commensal organisms were distributed three times a year. Participating laboratories were required to report on the presence of ‘mycobacteria’ and on the time required to obtain a positive result. The overall level of performance with the mycobacteria culture external quality assessment specimens remained consistently high, with an average success rate of 94% over 10 years. The mean time-to-positive decreased from 24 to 17 days during the previous 8 years. A survey questionnaire, circulated in 2002, addressed the use of continuous automated mycobacterial liquid culture (CAMLiC) and molecular methods. The increase in the use of rapid culture methods for the detection of Mycobacterium tuberculosis has resulted in an overall reduction in time-to-positive data reported by participants, and has provided an indication of participants’ ability to meet the 21-day target recommended by the CDC for the detection and identification of M. tuberculosis
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Very low ozone episodes due to polar vortex displacement
The large-scale ozone distribution over the northern hemisphere undergoes strong fluctuationseach winter on timescales of up to a few weeks. This is closely linked to changes in the stratosphericpolar vortex, whose shape, intensity and location vary with time. Elliptical diagnosticparameters provide an empirical description of the daily character of the polar vortex. Theseparameters are used as an objective measure to define two characteristic wintertime vortexdisplacements, towards northern Europe and Canada, respectively. The large-scale structuresin both the stratosphere and troposphere and the 3D ozone structures are determined for bothvortex displacement scenarios. A linear ozone transport model shows that the contribution ofhorizontal ozone advection dominates locally in the middle stratosphere. Nevertheless, thelargest contribution is due to vertical advection around the ozone layer maximum. The findingsare in agreement with an EOF analysis which reveals significant general modes of ozone variabilitylinked to polar vortex displacement and to phase-shifted large-scale tropospheric waves.When baroclinic waves travel through the regions of vortex-related ozone reduction, the combinedeffect is to produce transient synoptic-scale areas of exceptionally low ozone; namelydynamically induced strong ozone mini-holes
Has high knowledge of HIV/AIDS among the youth translated into positive sexual behavior in Northern Uganda?
Uganda has been hailed for combating the HIV/AIDS epidemic from an 18% prevalence in 1992 to only 6.1% . However, it rose to 6.4% in 2004/5. Northern Uganda, which faced political turmoil and insurgency for 20 years, presents a mixed picture, with the highest prevalence, 9.4% , in the country. The main objective of the research was to investigate the relationship between socio-economic characteristics, knowledge and practices towards HIV/AIDS among youth in Northern Uganda Region. Data on 910 youth from Northern Uganda was extracted from the national Uganda demographic and health survey of 2006. Univariate, bivariate and multivariate analyses were applied. Results from multivariate analysis show that age, residence, education, occupation, knowledge of one who has died from or is sick with AIDS and risk perceptions were significant predictors of condom use at last sex. Only sex was observed to be significantly related to willingness to be tested for HIV. In conclusion, although knowledge about HIV is important, translating it into behavior or practices to prevent or protect individuals from contracting HIV is essential. There is a need for sensitizing youth on the need to adopt safe sexual behavior. A comprehensive school sex education programme that scales up the understanding of safe behavior and enables girls to negotiate for safe sex will be required. The findings have important implications for the development of primary HIV/AIDS prevention programs for youth in war-torn areas.Résumé: L'Ouganda abstrait a été grêlé pour combattre l'épidémie de HIV/SIDA de la prédominance de 18% en 1992 à 6.1% . Cependant il a maintenant atteint 6.4% dans 2004/5. L'Ouganda nordique qui a fait face à l'agitation et à l'insurrection politiques pendant les 20 dernières années de présents une image mélangée avec la plus forte présence de 9.4% dans le pays. L'objectif principal de la recherche était d'étudier le rapport entre les caractéristiques, la connaissance et les pratiques socio-économiques vers le HIV/SIDA parmi la jeunesse dans la région nordique de l'Ouganda. Des données sur la jeunesse 910 d'Ouganda nordique ont été extraites à partir de l'Ouganda national démographique et de l'enquête de santé de 2006. Des analyses univariables, bivariate et multivariables ont été appliquées. Les résultats de l'analyse multivariable prouvent que l'âge, la résidence, l'éducation, le métier, la connaissance d'un mort ou le malade du SIDA et des perceptions de risque étaient les facteurs prédictifs significatifs de sexe d'utilisation de condom enfin. On a observé seulement le sexe pour être sensiblement relié avec la volonté de déterminer HIV. En conclusion bien que la connaissance au sujet d'HIV soit importante, la traduction de lui dans le comportement ou les pratiques d'empêcher ou protéger des individus contre contracter HIV est essentielle. Il y a besoin de sensibiliser la jeunesse sur la nécessité d'adopter le comportement sexuel sûr. Un programme d'éducation de sexe d'école d'enseignement secondaire qui mesure vers le haut de l'arrangement du comportement sûr et permet à des filles de négocier pour le sexe sûr sera exigé. Les résultats ont des implications importantes pour le développement des programmes primaires de prévention du SIDA d'HIV pour la jeunesse dans des secteurs déchirés par guerre.Mots clés: La connaissance, HIV/SIDA, jeunesse, positif, comportement sexue
Spousal sexual violence, sexual behavior and sexually transmitted infections among ever-married women in Uganda
Despite the increasing recognition of the significance of spousal sexual violence in developing countries, evidence on its consequences for reproductive health remains limited. The aim of the paper was to examine the relationship between spousal sexual violence (SSV) and sexually transmitted infections (STIs) using a sample of 1749 ever-married women, from the 2006 Uganda Demographic and Health Survey. Pearson Chi-square tests and binary logistic regressions were used to investigate associations between SSV, STIs and selected reproductive health outcomes. From the analyses, 25% and 15% of ever-married women experienced SSV and reported STIs, respectively in the last 12 months. Women who experienced SSV were twice more likely to have had STIs in the last 12 months compared to those who did not. SSV is an important social and public health problem having implications on women's reproductive health and interventions to improve it should directly address the issue of spousal sexual violence
First Observations of Benthos and Seston from a Submersible in the Lower St. Lawrence Estuary
Six dives with the submersible PISCES IV have permitted a unique description of the benthic and pelagic environments of a large, deep Canadian estuary. The estuarine floor and continental slopes are divided into five depth-dependent benthic zones. In order of decreasing depth are the Bathyal Trough Zone, the lnfaunal Zone, the Ophiura Zone, the Ice Rafting Zone and the Wave Base Zone. The zonal boundaries are based on changes in the faunal community, sediment texture, current energy, level of bioturbation and suspended particulate loading. Biological resuspension appears important in the Bathyal Trough and lnfaunal Zones. Current resuspension dominates the Ophiura and Ice Rafting Zones with storm waves additionally reworking the Wave-Base sediments. Seston characteristics are strongly influenced by the source and dynamics of the host water mass. The Surface Layer, the entrained outflow from the St. Lawrence River, is the source of most suspended matter found beneath. Large particles, mostly organo-mineral aggregates, become even larger with depth and indicate a rapid downward transfer of suspended sediment. The upper Intermediate Layer is complicated by stratified zones of turbulence that temporarily reduce the floe size. With the absence of such fine water structure, the lower Intermediate Layer is characterized by long chains of marine "snow" joined by delicate filaments. The Bottom Layer, a zone of increased turbulence, had aggregates breaking up into a haze of fine particles.Six plongées à bord du submersible Pisces IV ont permis de décrire les milieux benthique et pélagique de l'estuaire, large et profond, du Saint-Laurent. Le fond de l'estuaire et les talus continentaux ont été divisés, selon la profondeur, en cinq zones benthiques. Ce sont, du fond vers la surface, la zone bathyale du chenal Laurentien, la zone endobenthique, la zone à Ophiura, la zone de dépôts glaciels et la zone sous l'influence des vagues. Ces zones ont été déterminées à partir des variations des populations macrobenthiques, de la texture des sédiments, de l'énergie des courants, du niveau de bioturbation et de la concentration des particules en suspension. La resuspension biologique semble être importante dans les zones bathyale et endobenthique, mais la resuspension par les courants domine dans les trois autres zones. Les sédiments de la zone sous l'influence des vagues peuvent aussi être remaniés par les vagues de tempêtes. Les caractéristiques du seston sont fortement influencées par la source et la dynamique des différentes masses d'eau. Une grande partie du matériel en suspension provient de la couche superficielle, entraîné par le courant du Saint-Laurent. Les grosses particules, surtout les agrégats organo-minéraux, sont de plus en plus grosses en profondeur, ce qui suppose une descente rapide du matériel en suspension vers le fond. Dans la couche intermédiaire supérieure, des zones de turbulence stratifiées réduisent temporairement la taille des agrégats. La partie inférieure de la couche intermédiaire ne contient pas de ces stratifications fines et est plutôt caractérisée par la présence de longues chaînes de particules rattachées par un filament délicat. Dans la couche de fond, l'accroissement de la turbulence transforme les agrégats en un brouillard de fines particules.Sechs Tauchmanôver mit dem U-Boot Pisces IV haben eine einzigartige Beschreibung der benthis-chen und pelagischen Umgebung einer grossen, tiefen, kanadischen Mùndung erlaubt. Der Aestuarboden und die Kon-tinentalhànge sind in fùnf tiefenbedingte benthische Zonen eingeteilt. Der Ordnung nach, in abnehmender Tiefe, liegen die bathyal Zone des Skt-Lorenz Kanals, die endobenthische Zone, die Ophiura Zone, die Eisstrandungs Zone und die Wellen-Einfluss-Zone. Die Zonengrenzen sind auf Verànderungen in der Faunenwelt, Sedimenttextur, Strômungsenergie, Niveau der Bioturbation und der Konzentration der Schwebstoffe gegrùndet. Biologische Resuspension ist in der bathyalen und endobentischen Zone wichtig, wàhrend die Resuspension durch die Strômung in der Ophiura und Eisstrandungszone ùberwiegt, mit zusàtzlicher Bearbeitung der Wellen-Basis-Elemente durch Sturmwellen. Seston Kennzeichen sind durch die Dynamik der Gastgewàsser stark beeinflusst. Ein grosser Teil der Schwebstoffe kommt aus der oberen Schicht und wird durch die Strômung des Skt Lorenz Stromes mitgeschleppt. Grosse Teile, meistens organischmineral Aggregate werden mit wachsender Tiefe noch grosser und zeigen ein schnelles Sinken der Schwebstoffe an. In der oberen Zwischenschicht verringern die stratifizierten Turbulen Zonen zeitweilig die Grosse der Aggregate. Der untere Teil der Zwischenschicht zeigt keine solche feinen Stratifikationen und kennzeichnet sich eher durch die Gegenwart von langen Ketten von Schwebstoffteilchen, die durch einen dùnnen Faden zusammenhalten. In der Grundschicht, einer Zone mit vermehrterTurbulenz, werden die Aggregate zu einem Nebel feiner Teilchen aufgebrochen
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