Panoptic geographies: an examination of all U.S. geographic dissertations          下载免费PDF全文

David H. Kaplan  Jennifer E. Mapes 《Geographical review》2015,105(1):20-40

The study of geography as a discipline has often employed a top‐down approach that examines the output of the field's most prominent members. In this paper, we provide a bottom‐up approach by analyzing geography dissertations. We start by assembling a database that includes the title, author, date, and university for every geographic doctoral dissertation written in the United States over the last 120 years. The database allows us to track the rise and fall of regions of interest and specific topics. It gives a broad overview of the different schools in geography and their influence within separate historical periods. And it permits a more empirically based delineation of geographical “eras” based on the commonality of words in dissertation titles. This work is at the convergence of the quantitative and qualitative; we quantify and visualize textual data to provide a more robust history of geography. The result is a new, more comprehensive way to look at the changing discipline of geography.  相似文献   

Effective ecosystem-based management must encourage regulatory compliance: A Gulf of California case study     

C.H. Ainsworth  H. Morzaria-Luna  I.C. Kaplan  P.S. Levin  E.A. Fulton  R. Cudney-Bueno  P. Turk-Boyer  J. Torre  G.D. Danemann  T. Pfister 《Marine Policy》2012

The Northern Gulf of California is an area important for small-scale fisheries in terms of economic activity and food security, but widespread non-compliance with fisheries regulations impedes effective management of resources and conservation efforts. Where a previous study evaluated quantitatively a theoretical situation in which all regulations are perfectly followed, this article compares a suite of recently proposed ecosystem-based management (EBM) policies against the expected benefits of full enforcement of current regulations. Policies evaluated include no-take marine protected areas (MPAs), breeding period closures, changes in hook size and fishing effort, and gear-specific spatial closures. No-take MPAs yield ecological benefits over a wide range of MPA sizes and characteristics, but do not increase overall catch. Seasonal closures are effective at reducing overfishing for the depleted leopard grouper (Mycteroperca rosacea); changing the hook size of artisanal longlines does not increase catch of either the target species or the assemblage, and gear-specific fishery closures for crab traps near Puerto Peñasco are effective at reducing overfishing of blue crab (Callinectes bellicosus and C. arcuatus). In general, full enforcement of existing regulations outperforms these EBM policies in terms of conservation benefits, but it may be less palatable to stakeholders as it requires major reductions in catch.  相似文献   

Propagating PZ 90 to WGS 84 Transformation Parameters     

Yuri A. Bazlov  Viktor F. Galazin  Boris L. Kaplan  Valery G. Maksimov  Vladimir P. Rogozin 《GPS Solutions》1999,3(1):13-16

The 29^th Research Institute recently published its latest transformation parameters for WGS and PZ 90. Because these tranformation parameter estimates were derived from stations located within Russia, variance-covariance propagation was carried out to study the benefits of a better global distribution of stations. An example that includes two stations in North America is presented. The transformation improves significantly. ? 1999 John Wiley & Sons, Inc.  相似文献   

Accurate X-ray position and multiwavelength observations of the isolated neutron star RBS 1774     

N. Rea  M. A. P. Torres  P. G. Jonker  R. P. Mignani  S. Zane  M. Burgay  D. L. Kaplan  R. Turolla  G. L. Israel  D. Steeghs 《Monthly notices of the Royal Astronomical Society》2007,379(4):1484-1490

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Thin magnetic hydrogen atmospheres and the neutron star RX J1856.5–3754     

Wynn C. G. Ho  David L. Kaplan  Philip Chang  Matthew van Adelsberg  Alexander Y. Potekhin 《Astrophysics and Space Science》2007,308(1-4):279-286

RX J1856.5–3754 is one of the brightest nearby isolated neutron stars, and considerable observational resources have been devoted to it. However, current models are unable to satisfactorily explain the data. We show that our latest models of a thin, magnetic, partially ionized hydrogen atmosphere on top of a condensed surface can fit the entire spectrum, from X-rays to optical, of RX J1856.5–3754, within the uncertainties. In our simplest model, the best-fit parameters are an interstellar column density N _H≈1×10²⁰ cm^?2 and an emitting area with R ^∞≈17 km (assuming a distance to RX J1856.5–3754 of 140 pc), temperature T ^∞≈4.3×10⁵ K, gravitational redshift z _g ～0.22, atmospheric hydrogen column y _H≈1 g cm^?2, and magnetic field B≈(3–4)×10¹² G; the values for the temperature and magnetic field indicate an effective average over the surface.  相似文献   

Scattering of electromagnetic radiation by turbulent plasma under cosmic conditions     

S. A. Kaplan  V. N. Tsytovich 《Astrophysics》1968,4(3):130-139

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A three-dimensional model for calculating the concentration distribution in inhomogeneous turbulence     

H. Kaplan  N. Dinar 《Boundary-Layer Meteorology》1993,62(1-4):217-245

A new approach for calculating the concentration distribution in inhomogeneous turbulence is suggested. The model is a 3-D model, constrained to describe incompressible flow. The model requires a knowledge of the covariance matrix of the Eulerian velocities and the two-point third moments. The model is applied for three types of turbulent field: homogeneous isotropic turbulence, constant flux neutral boundary layer and free convective turbulence. The required Eulerian moments are calculated using the eddy model of the turbulent field. Concentration moments are calculated and results are compared to experimental data. Other model predictions which have no experimental support can be compared to measurements when available.  相似文献   

A variable source area for groundwater evapotranspiration: impacts on modeling stream flow          下载免费PDF全文

Yin‐Phan Tsang  George Hornberger  Louis A. Kaplan  J. Denis Newbold  Anthony K. Aufdenkampe 《水文研究》2014,28(4):2439-2450

Evapotranspiration (ET) plays a crucial role in catchment water budgets, typically accounting for more than 50% of annual precipitation falling within temperate deciduous forests. Groundwater ET is a portion of total ET that occurs where plant roots extend to the capillary fringe above the phreatic surface or induce upward movement of water from the water table by hydraulic redistribution. Groundwater ET is spatially restricted to riparian zones or other areas where the groundwater is accessible to plants. Due to the difficulty in measuring groundwater ET, it is rarely incorporated explicitly into hydrological models. In this study, we calibrated Topographic Model (TOPMODEL) using a 14‐year hydrograph record and added a groundwater ET pathway to derive a new model, Groundwater Evapotranspiration TOPMODEL (GETTOP). We inspected groundwater elevations and stream flow hydrographs for evidence of groundwater ET, examined the relationship between groundwater ET and topography, and delineated the area where groundwater ET is likely to take place. The total groundwater ET flux was estimated using a hydrological model. Groundwater ET was larger where the topography was flat and the groundwater table was shallow, occurring within about 10% of the area in a headwater catchment and accounting for 6 to 18% of total annual ET. The addition of groundwater ET to GETTOP improved the simulation of stream discharge and more closely balanced the watershed water budget. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

The POINT-AGAPE survey – II. An unrestricted search for microlensing events towards M31     

V. Belokurov  J. An  N. W. Evans  P. Hewett  P. Baillon  S. Calchi Novati  B. J. Carr  M. Crézé  Y. Giraud-Héraud  A. Gould  Ph. Jetzer  J. Kaplan  E. Kerins  S. Paulin-Henriksson  S. J. Smartt  C. S. Stalin  Y. Tsapras  M. J. Weston 《Monthly notices of the Royal Astronomical Society》2005,357(1):17-37

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Fluctuations of the Última Esperanza ice lobe (52°S), Chilean Patagonia,during the last glacial maximum and termination 1     

E.A. Sagredo  P.I. Moreno  R. Villa-Martínez  M.R. Kaplan  P.W. Kubik  C.R. Stern 《Geomorphology》2011,125(1):92-108

We present a new record from the Última Esperanza region (51°25’-52°25'S), southwestern Patagonia, to unravel the timing and structure of glacial fluctuations during the Last Glacial Termination (T1). This sector of southern South America represents the only windward-facing continental landmass in the Southern Hemisphere that intersects the core of the Southern Westerly Wind belt.Geomorphic, stratigraphic and geochronological evidence indicate the following stages during and since the Last Glacial Maximum (LGM): (i) deposition of prominent moraine complexes during at least two advances dated between ~ 39 and > 17.5 ka; (ii) development of an ice-dammed proglacial lake (glacial lake Puerto Consuelo) accompanying ice recession; (iii) active deposition of moraine complexes at intermediate positions followed by recession at ≥ 15.2 ka; (iv) lake level drop and subsequent stabilization between 15.2-12.8 ka; (v) a glacial readvance in glacial lake Puerto Consuelo between 14.8-12.8 ka; (vi) ice recession, stabilization, and lake level lowering between 12.8-10.3 ka; and (vii) glacial withdrawal and disappearance of glacial lake Puerto Consuelo prior to 10.3 ka. By comparing our results with the chronologies from neighboring regions we explore whether there was a consistent temporal/geographic pattern of glacial fluctuations during the LGM and T1, and examine their implications at regional, hemispheric, and global scales. The correspondence of these variations with key paleoclimate events recorded in the Southern and the Northern Hemispheres suggest a common forcing that, most likely, propagated through the atmosphere. Regional heterogeneities at millennial timescales probably reflect the influence of processes related to deep ocean circulation, and changes in the position/intensity of the Antarctic Polar Front and Southern Westerly Winds.  相似文献