Proper motions of 59 766 stars absolutized using galaxies in 149 sky fields (PUL2)

The PUL2 catalog has been photographically compiled in Pulkovo according to Deutch's plan. The catalog contains the mean coordinates of stars in the ICRS system at epoch J2000.0 and their original absolute proper motions. The photographic observations were performed with a normal astrograph. The first and second epochs of the photographic plates are 1937–1965 and 1969–1986, respectively. The PUL2 fields uniformly cover the northern sky. The mean difference between the epochs is 24 years. At least three pairs of plates are available for each field. There are one-hour and five-minute exposures on all plates. One pair of plates was taken with a diffraction grating. Only bright reference stars were measured on the pairs of plates with a grating. Based on a reduction model with six constants and using faint (\(15\mathop m\limits_. 2\)) reference stars, we determined the relative proper motions of the stars. We used ～700 galaxies for absolutization. The mean errors in the relative proper motions of the PUL2 stars are 5.5 mas yr^?1 (milliarcseconds per year) in μ_α cos δ and 5.9 mas yr^?1 in μ_δ. When using galaxies, the mean absolutization error is 7.9 mas yr^?1 in both coordinates. By comparing the PUL2 and HIPPARCOS catalogs, we determined the components of the residual rotation vector ω for HIPPARCOS relative to the extragalactic (equatorial) coordinate system: ω_x,y,z=(?0.98, ?0.03, ?1.66)±(0.47, 0.38, 0.42) mas yr^?1. The mean error of one absolute proper motion of a bright PUL2 star in external convergence is 9 mas yr^?1 in both coordinates.     

Relationships between hydraulic conductivity distribution and synsedimentary faults,Rharb-Mamora basin,Morocco; Hydrogeological,geostatistical and modeling approaches

This paper deals with the relationship between the physical characteristics of the Rharb-Mamora basin (Northern Morocco) and the distribution of hydraulic conductivity values in the Plio-Quaternary aquifer. A steady state groundwater model has been calibrated using these values. The distribution of hydraulic conductivity corresponds to a hydrodynamic partition with permeabilities of 2×10^–3 to 5×10^–2 ms^–1 (in the coastal part). A numerical modeling process shows a relative error map between calculated and measured piezometric surfaces, in order to facilitate calibration in steady state.The distribution of hydraulic conductivity values, and the lateral variation of sequences (deduced from engineering geology methods e.g. hydrogeological drilling data, seismic reflection interpretation, and geostatistical analysis), are controlled by synsedimentary fault activity, which deepened the Mio-Pliocene basement resulting in a thickening of overlying permeable rocks.

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Resumen Esta nota trata la relación existente entre las características físicas y la distribución de la conductividad hidráulica de los acuíferos subyacentes de la cuenca del Rharb-Mamora (norte de Marruecos). Para la simulación del flujo del agua subterránea se ha establecido un modelo en régimen permanente. La distribución de la conductividad hidráulica corresponde a un reparto hidrodinámico cuyo grado de permeabilidad es generalmente alto: desde 2×10^–3 hasta 5×10^–2 ms^–1 (zona costera). Con el objetivo de facilitar la calibración del modelo en régimen permanente, el proceso numérico realizado mostró errores relativos entre la piezometría calculada y medida. La distribución de los valores de permeabilidad y la variación lateral de las unidades permeables ha sido deducida a partir de métodos de geología aplicada (análisis de los sondeos hidrogeológicos, interpretación de los perfiles de sísmica de reflexión y aplicación de métodos geoestadísticos), y están controlados por la actividad de las fallas sinsedimentarias que influyen sobre la topografía del basamento mio-plioceno y el grosor de las unidades acuíferas.

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Résumé Cette note traite la relation entre les caractéristiques physique du bassin Rharb-Mamora (Nord du Maroc) et la répartition de la conductivité hydraulique du réseau aquifère. Le modèle de simulation des écoulements souterrains a été établi en régime permanent. La distribution de la conductivité hydraulique correspond à un découpage hydrodynamique dont le degré de perméabilité est généralement bon entre 2×10^–3 to 5×10^–2 ms^–1 (zone côtière). Afin de faciliter le calage en régime permanent, le code numérique établi permet de mettre en évidence les erreurs relatives entre la piézométrie calculée et mesurée.La distribution des valeurs de perméabilité et la variation latérale des unités perméables, déduites des méthodes de la géologie appliquée (analyse des forages hydrogéologiques, interprétation des profils sismique réflexion et analyse géostatistique), sont contrôlées par lactivité des failles synsédimentaires qui influencent lapprofondissement du substratum hydrogéologique mio-pliocène et lépaississement des corps perméables.

     

The Praesepe open cluster and the galactic distance scale

Updated proper motions for 328 probable members of the Praesepe are used to determine the distance to this open cluster by Hertzsprung's geometric method. The cluster distance was found to be r=171±15 pc, which corresponds to the distance modulus $V_0 - M_V = 6\mathop .\limits^m 16 \pm 0.19$ . The distance scale for open clusters is discussed.     

GPR reflection characteristics and depositional models of mud volcanic sediments—Wushanting mud volcano field, southwestern Taiwan

Ground penetrating radar (GPR) survey was conducted in the Wushanting mud volcano field (Yanchao, Kaohsiung) using a 500 MHz antennae, which allowed high-resolution imaging of subsurface structures. Seven GPR reflection characteristics are recognized. Sigmoid GPR reflection patterns resulted from a recent mud lobe deposited above an underlying older mud lobe front. Contorted GPR facies resulted from recent mud flow which encountered obstacles. Subparallel reflections resulted from mud volcano deposits of limited flowability, low velocity and gentle gradient. Hummocky reflection patterns are formed by interfingering of recent mud lobes building onto low land. Disrupted GPR facies were due to lateral breaks of continuity from mud cracks, which, according to field observation, can provide channels for erosion and form deeper erosion gullies. GPR time slices of different depths are rendered as a three-dimensional model. Approximately orbicular GPR reflection characteristics can indicate arcuate stacked mud lobe fronts of different periods. Some depositional models to explain GPR reflection characteristics can be founded upon observations of recent sedimentary phenomena. The models of this study may be applied to paleoenvironments and the depositional evolution of mud volcanoes in similar geological settings.     

Card-carrying hunters, rural poverty, and wildlife decline in northern Côte d'Ivoire

This paper examines wildlife decline in northern Côte d'Ivoire with emphasis on the political-economic and cultural dimensions of market hunting. Hunting and the trade in wild animal meat are situated within the economic diversification strategies of impoverished farmers and the flourishing of hunter associations. The role of hunter associations is critical in the rise in the number of hunters and firearms in the case study area of Kakoli. Initiation into the national hunters' association, Binkadi, allows card-carrying members to bear arms without legal repercussions. Higher quality arms and rural poverty motivate many of these recruits to engage in market hunting. Game market surveys for 1981–82 and 1997–99 in Kakoli show tremendous pressure on both vulnerable and robust species alike. Game depletion is conceptualized as the outcome of interacting social and biophysical processes that produce hunting pressure and habitat change. By drawing attention to the political-economic, ecological, and cultural dimensions of wildlife decline, this study implicates a diversity of actors and institutions in the dynamics of game depletion.     

Approaches to sustainable forestry in the Piatra Craiului National Park

Declared in 1990, the Piatra Craiului is one of Romania's 15 national parks and biosphere reserves. It has exceptional scenic and biodiversity value but is under threat from unsustainable agricultural, forestry and tourism management. The paper examines these threats in a historical context, regarding both the growth of the town of Braşov and areas of dispersed rural settlement on the mountain edge, and argues that a sustainable future will require negotiation between the park authorities and all stakeholders, including the local communities and private woodland owners who have benefited or will benefit from restitution. The way forward is explored with forest management in a central role. First, the certification of woodlands, along with the establishment of forest user groups and community woodlands, should help to reconcile the conflicting interests in the woodlands and in wood processing in support of sustainability. Second, the overgrazing of the meadows which is degrading the pastures, restricting forest regeneration and conflicting with large carnivore conservation, could be moderated by the growth of ecotourism linked with bears and wolves which would generate a new source of income to compensate farmers for reducing their flocks – given the importance of the biodiversity resources and the socio-economic pressures – and the paper therefore considers how new approaches to forest management might provide a basis for conservation and sustainable development. It will be for the recently-established national park management system – developed with World Bank Global Environment Facility funding – to take these ideas forward in due course. This revised version was published online in July 2006 with corrections to the Cover Date.     

Promoting Lifelong Professional Development in Geography Education: International Perspectives on Developing the Scholarship of Teaching in Higher Education in the Twenty‐First Century*

Whereas the global march towards the professional development of geography teachers in schools was, perhaps, the major achievement in geography education of the twentieth century, promoting the professional development of faculty teaching geography in higher education is one of the major challenges that faces us in geography education for the twenty‐first century. What little educational development is currently provided for faculty teaching in universities is largely generic. There is a need for a disciplinary specific component in educational development, both for the initial training of faculty and for their continuing professional development. This article explores how the professional development of faculty is related to the international debate about developing the scholarship of teaching and learning in higher education. It reviews some recent initiatives, particularly from the United States and the United Kingdom, and examines the role of national associations and international networks in supporting faculty teaching geography in higher education. Some of the challenges involved in professionalizing teaching geography in higher education are discussed. The article ends with some suggestions for promoting lifelong professional development in geography in higher education nationally and internationally.     

Alluvial deposits from the strike-slip fault Lo River Basin (Oligocene/Miocene), Red River Fault Zone, north-western Vietnam

The Lo River Basin (LRB) is one of several narrow sedimentary basins associated with the main faults of the Red River Fault Zone separating the South China and Indochina microplates. The basin is located on the NE boundary of the high-grade metamorphic Con Voi Massif and the sedimentary and metasedimentary Viet Bac fold zone in north-eastern Vietnam.The LRB is filled with over 6000 m of Oligocene/Miocene alluvial deposits. The source area was probably located on the NE margin of the basin and was composed mostly of low-grade metamorphic rocks with a minor component of sedimentary rocks. Three alluvial systems are recognised. The oldest system was a proximal braided river system, with the minor occurrence of alluvial fans. The younger systems record changes in clast composition and lithofacies, which suggests a transition from a distal braided river to a distal braidplain system. The LRB fill shows a range of features characteristic of strike-slip fault basins. The origin of the LRB is correlated with the left-lateral transtensional regime. The present shape of the basin is a result of post-sedimentation tectonic activity.     

Amalgamation surfaces, bed thicknesses, and dish structures in sand-rich submarine fans: numeric differences in channelized and unchannelized deposits and their diagnostic value

Hydraulic differences between channelized and unchannelized flows in sand-rich submarine fans result in different distributions of amalgamation surfaces, bed thicknesses, and dish structures in successions of these two different environments. Distribution trends of these fabrics were quantified for the sand-rich fans of the Reiselsberger Sandstein (Cenomanian–Turonian). These trends can be used as criteria to distinguish channelized from unchannelized paleoenvironments of sand-rich submarine fans.

Amalgamation surfaces in the studied fans' channelized regions are considerably more abundant than in the unchannelized fan areas. In unchannelized deposits, tabular amalgamation surfaces outnumber nontabular ones, whereas the opposite occurs in channelized successions. These results indicate a higher degree of erosive power of gravity-driven sediment flows in channels as a result of a greater flow thickness, higher flow velocity, and turbulence.

The average turbidite layer thickness in channelized successions is markedly greater than in unchannelized deposits (“layer” as defined herein). This is mainly attributed to the combined effects of differences in sediment fall-out rate and the inefficiency of sand-rich suspensions to transport sand. In the proximal and channelized fan areas, more sediment is deposited from a flow in the form of a layer than in distal unchannelized fan regions despite a higher degree of erosion in channels. The greater average bed thickness in channel fills is a function of layer thickness and more frequent amalgamations (“bed” as defined herein).

Dish structures seem to be considerably more common in midfan than in outer-fan successions. This may indicate a higher sedimentation rate from individual suspension currents in midfan areas.     

The concept of self-reliance in community development initiatives in the Cameroon grassfields

The Grassfields of Cameroon is a fertile ground for self-help efforts. This paper examines the resurgence and role Village Development Associations (VDAs) are playing in national and community development. Community members are increasingly shouldering the adverse consequences of the economic downturn and the growing inability of the state to provide economic and social development by initiating, mobilising and galvanising their own resources in the quest for improving their standard of living. The reliance on indigenous technology and local human resources has led to overwhelming popular participation in community- driven development. This revised version was published online in July 2006 with corrections to the Cover Date.