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The coexistence of Baird’s tapir (Tapirus bairdii) and indigenous hunters in northeastern Honduras

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Integrative Zoology 2012年第4期7卷 429-438页

作者： Marc DUNN Nereyda ESTRADA derek A.smith Department of Geography and Environmental Studies Carleton UniversityOttawaOntarioCanada International Union for Conservation of Nature(IUCN)Honduras Tapir Specialist Group TegucigalpaHonduras

The Baird’s tapir(Tapirus bairdii)is a popular game species throughout Central America,particularly among in-digenous populations,and is currently *** on Miskitu hunting was conducted over 4 months in a remote region in northeastern Honduras that overlaps with the Río Plátano Biosphere *** hunting zone was mapped together with hunters and interviews were conducted with elders and other community mem-bers about tapir *** show that tapir harvesting is targeted toward specific habitats at specific times of *** rates for one year suggest that tapir hunting in the area exceeds estimates of maximum sustain-able ***,field surveys reveal the presence of tapir within 1 km of the community,and its harvest tends to be nearby,in both forested and agricultural landscapes,suggesting that the animal has not been depleted in the *** appears that the existence of forest areas adjacent to the hunting zone that do not experi-ence hunting,together with the anthropogenic habitats created through shifting cultivation,are factors that help explain the presence of tapirs in the *** article concludes with a discussion regarding the potential posi-tive role of indigenous hunters in tapir conservation throughout its distribution range.

关键词： Baird’s tapir Honduras indigenous hunting Miskitu Río Plátano Biosphere Reserve

Sol-gel derived nanocrystalline and mesoporous barium strontium titanate prepared at room temperature

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Particuology 2011年第3期9卷 235-242页

作者： Mohammad Reza Mohammadi derek j.Fray Department of Materials Science & Engineering Sharif University of Technology Department of Materials Science & Metallurgy University of Cambridge

Perovskite-type barium strontium titanate （BST） thin films and powders with nanocrystalline and mesoporous structure were prepared by a straightforward particulate sol-gel route at room temperature. The prepared sol had a narrow particle size distribution of about 20 nm. X-ray diffraction （XRD） revealed that phase composition and preferable orientation growth of BST depended upon the annealing temperature. Transmission electron microscope （TEM） images showed that the crystallite size of the powders decreased with increasing annealing temperature from 8 nm at 25 ℃ down to 5 nm at 800 ℃. Field emission scanning electron microscope （FE-SEM） analysis and atomic force microscope （AFM） images revealed that BST thin films had mesoporous and nanocrystafiine structure with average grain size of 3Onm at 600 ℃. Based on Brunauer-Emmett-Teller （BET） analysis, the synthesized BST showed mesoporous structure containing nnres with needle, and nlate shanes and BET surface area in the range of 49-32 m^2/g at 500-800℃

关键词： Barium strontium titanate Room temperature Sol-gel chemistry Nanostructure

Template-based growth of titanium dioxide nanorods by a particulate sol-electrophoretic deposition process

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Particuology 2011年第2期9卷 161-169页

作者： Mohammad Reza Mohammadi Farideh Ordikhani derek j.Fray Farzad Khomamizadeh Department of Materials Science & Engineering Sharif University of Technology Department of Materials Science & Metallurgy University of Cambridge

TiO2 nanorods have been successfully grown into a track-etched polycarbonate （PC） membrane by a particulate sol-electrophoretic deposition from an aqueous medium. The prepared sols had a narrow particle size distribution around 17 nm and excellent stability against aging, with zeta potentials in the range of 47-50 mV at pH 2. It was found that TiO2 nanorods were grown from dilute aqueous sol with a low, 0.1-M concentration. Fourier transform infrared spectroscopy （FT-IR） analysis confirmed that a full conversion of titanium isopropoxide was obtained by hydrolysis, resulting in the formation of TiO2 particles. X-ray diffraction （XRD） results revealed that TiO2 nanorods dried at 100℃ were a mixture of anatase and brookite phases, whereas they were a mixture of anatase and futile structures at 500℃. Moreover, the rutile content of the TiO2 nanorods was higher than that of TiO2 powders. Transmission electron microscope （TEM） images confirmed that TiO2 nanorods had a smooth morphology and longi- tudinal uniformity in diameter. Field emission scanning electron microscope （FE-SEM） images showed that TiO2 nanorods grown by sol-electrophoresis from the dilute aqueous sol had a dense structure with a uniform diameter of 200 rim, containing small particles with an average size of 15 nm. Simultaneous differential thermal （SDT） analysis verified that individual TiO2 nanorods, grown into a PC template, were obtained after annealing at 500℃. Based on kinetic studies, it was found that uniform TiO2 nanorods with high-quality morphology were obtained under optimum conditions at an applied potential of 0.3 V/cm and a deposition time of 60 min.

关键词： Nanorod Crystal morphology Electrophoretic deposition Sol-electrophoresisTitanium dioxide

Do cratons preserve evidence of stagnant lid tectonics?

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Geoscience Frontiers 2018年第1期9卷 3-17页

作者： derek Wyman School of Geosciences The University of Sydney

Evidence for episodic crustal growth extending back to the Hadean has recently prompted a number of numerically based geodynamic models that incorporate cyclic changes from stagnant lid to mobile lid tectonics. A large part of the geologic record is missing for the times at which several of these cycles are inferred to have taken place. The cratons, however, are likely to retain important clues relating to similar cycles developed in the Mesoarchean and Neoarchean. Widespread acceptance of a form of plate tectonics by ～3.2 Ga is not at odds with the sporadic occurrence of stagnant lid tectonics after this time. The concept of scale as applied to cratons, mantle plumes and Neoarchean volcanic arcs are likely to provide important constraints on future models of Earth's geodynamic evolution. The Superior Province will provide some of the most concrete evidence in this regard given that its constituent blocks may have been locked into a stagnant lid relatively soon after their formation and then assembled in the next global plate tectonic interval. Perceived complexities associated with inferred mantle plume — volcanic arc associations in the Superior Province and other cratons may be related to an over estimation of plume size. A possible stagnant lid episode between ～2.9 Ga and ～2.8 Ga is identified by previously unexplained lapses in volcanism on cratons, including the Kaapvaal, Yilgarn and Superior Province cratons. If real, then mantle dynamics associated with this episode likely eliminated any contemporaneous mantle plume incubation sites, which has important implications for widespread plumes developed at ～2.7 Ga and favours a shallow mantle source in the transition zone. The Superior Province provides a uniquely preserved local proxy for this global event and could serve as the basis for detailed numerical models in the future.

关键词： Archean Mantle overturn Superior Province Mantle plumes Stagnant lid tectonics

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Transient Expression of Virally Delivered Meganuclease In Planta Generates Inherited Genomic Deletions

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Molecular Plant 2015年第8期8卷 1292-1294页

作者： Arik Honig Ira Marton Michal Rosenthal j. jeff smith Michael G. Nicholson derek jantz Amir Zuker Alexander Vainstein Danziger Innovations Ltd. Mishmar Hashiva Village Beit Dagan 50297 Israel Precision Biosciences 302 East Pettigrew Street Dibrell Building Suite A-100 Durham NC 27701 USA Institute of Plant Sciences and Genetics in Agriculture Robert H. Smith Faculty of Agriculture Food and Environment Hebrew University of Jerusalem Rehovot 76100 Israel

Dear Editor The use of sequence-specific nucleases for plant genomic DNA mutagenesis is an exciting and rapidly developing tech- nology （Voytas and Merchant, 2013; Baltes and Voytas, 2014）. To date, most mutated plants have been recovered from transgenic plants stably expressing nucleases. However, transient nuclease delivery by plant DNA- and RNA-based viral vectors followed by regeneration of plantlets from modi- fied tissues has emerged as an alternative, efficient strategy in some plant species （Marton et al., 2010; Baltes et al., 2014）. Delivery of nucleases by plant RNA viruses is particularly attractive because they typically do not integrate into the plant genome, and therefore the mutated plants are not classified as transgenic （Marton et al., 2013; Voytas and Gao, 2014）.

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Bank erosion in an Andean páramo river system: Implications for hydro-development and carbon dynamics in the neotropical Andes

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journal of Mountain Science 2019年第2期16卷 243-255页

作者： derek j.MARTIN Christopher ELY Beverley C.WEMPLE Department of Geography and Planning Appalachian State University Department of Geography University of Vermont

The páramo of the Northern Andes provide critically important ecosystem services to the Northern Andean region in the form of water provisioning and carbon sequestration, both of which are a result of the páramo?s organic-rich soils. Little is known, however, about the hydro-geomorphic characteristics of the rivers that drain these ecosystems. With impending plans for widespread hydro-development and increasing implementation of carbon-sequestering compensation for ecosystem services programs in the region it is imperative that we develop a thorough understanding of the hydrogeomorphic role that rivers play in this unique ecosystem. The objective of this study was to quantify bank erosion along an Amazonian headwater stream draining a small, relatively undisturbed páramo catchment to gain a better understanding of the natural erosion regime and the resulting sediment contributions from this unique ecosystem. This study implemented a combination of field, laboratory, and Geographic Information Systems techniques to quantify bank erosion rates and determine a bank erosion sediment yield from the Ningar River, a small páramo catchment(22.7 km^2) located in the eastern Andean cordillera of Ecuador. Results show that bank erosion rates range from 3.0 to ≥ 390.0 mm/yr, are highly episodic, and yield at least 487 tons of sediment annually to the Ningar River. These results imply that 1) páramo ecosystems substantially contribute to the sediment load of the Amazon River basin; 2) bank erosion is a potentially significant flux component of basin-scale carbon cycles in páramo ecosystems; and 3) hydrologic alteration campaigns(dam building) will likely critically alter these contributions and concomitantly disconnect a critical source of sediment and nutrients to downstream ecosystems.

关键词： Bank erosion Páramo Fluvial geomorphology Andes

A novel application of fluidization-Integrating three processes in reclaiming foundry sand

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Particuology 2010年第6期8卷 595-598页

作者： derek Geldart jim Lewis Powder Research Ltd Leeds University UK Coastal River Technologies PLLC USA

Immersion of automotive parts in a fluidized bed of foundry sand is used to both strip the castings free from moulding sand and to heat-treat the castings at 500℃. The fluid bed is heated by hot gases from a burner directed first into a serpentine heat exchanger located near one side-wall of the rectangular tank, and then into a distributor consisting of horizontal sparger pipes having maintenance standpipes fixed into their upper surfaces.

关键词： Removal of moulding sand Castings Fluidized beds Heat transfer Foundries

Generalized Baumslag-Solitar Graphs with Soluble Fundamental Groups

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Algebra Colloquium 2014年第1期21卷 53-58页

作者： Alberto L. Delgado derek j.S. Robinson Mathew Timm vDepartment of Mathematics illinois State University Normal IL 61790 USA Department of Mathematics University of Illinois at Urbana-Champaign Urbana IL 61801 USA Department of Mathematics Bradley University Peoria IL 61625 USA

It is shown that the generalized Baumslag-Solitar graphs which have soluble fundamental groups can be constructed from four simple types of graph by a process of decoration. The method of proof is elementary and emplo... 详细信息

关键词： generalized Baumslag-Solitar graph soluble fundamental group

Dry powder platform for pulmonary drug delivery

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Particuology 2008年第4期6卷 225-238页

作者： derek Ivan Daniher jesse Zhu Graduate Program in Biomedical Engineering Department of Chemical and Biochemical EngineeringThe University of Western OntarioLondonOntarioCanada

The phenomenon of particle interaction involved in pulmonary drug delivery belongs to a wide variety of disciplines of particle technology, in particular, fluidization. This paper reviews the basic concepts of pulmonary drug delivery with references to fluidization research, in particular, studies on Geldart group C powders. Dry powder inhaler device-formulation combination has been shown to be an effective method for delivering drugs to the lung for treatment of asthma, chronic obstructive pulmonary disease and cystic fibrosis. Even with advanced designs, however, delivery efficiency is still poor mainly due to powder dispersion problems which cause poor lung deposition and high dose variability. Drug particles used in current inhalers must be 1–5 μm in diameter for effective deposition in small-diameter airways and alveoli. These powders are very cohesive, have poor flowability, and are difficult to disperse into aerosol due to cohesion arising from van der Waals attraction. These problems are well known in fluidization research, much of which is highly relevant to pulmonary drug delivery.

关键词： Dry powder inhaler Interparticle forces Aerosol Pulmonary drug delivery Carrier particle Fluidization